Tag: Aging Research

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Rapamycin’s Therapeutic Potential in Treating Werner Syndrome

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In this new study, researchers from Japan investigated the molecular mechanisms of subcutaneous fat dysfunction in Werner syndrome.

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Between 1904 and 2008, researchers found that approximately 75% of patients with Werner syndrome (WS) worldwide were of Japanese descent. WS is a rare genetic disorder that causes premature aging and increases the risk of various age-related diseases, such as diabetes, cardiovascular disease and cancer. One of the hallmarks of WS is the loss of subcutaneous fat, which is the layer of fat under the skin that helps regulate body temperature and store energy. Subcutaneous fat loss leads to severe insulin resistance, which means that the body cannot use glucose effectively and has high blood sugar levels. But what causes subcutaneous fat loss in WS? And how does it affect the metabolism and health of WS patients? 

In a new study, researchers Daisuke Sawada, Hisaya Kato, Hiyori Kaneko, Daisuke Kinoshita, Shinichiro Funayama, Takuya Minamizuka, Atsushi Takasaki, Katsushi Igarashi, Masaya Koshizaka, Aki Takada-Watanabe, Rito Nakamura, Kazuto Aono, Ayano Yamaguchi, Naoya Teramoto, Yukari Maeda, Tomohiro Ohno, Aiko Hayashi, Kana Ide, Shintaro Ide, Mayumi Shoji, Takumi Kitamoto, Yusuke Endo, Hideyuki Ogata, Yoshitaka Kubota, Nobuyuki Mitsukawa, Atsushi Iwama, Yasuo Ouchi, Naoya Takayama, Koji Eto, Katsunori Fujii, Tomozumi Takatani, Tadashi Shiohama, Hiromichi Hamada, Yoshiro Maezawa, and Koutaro Yokote from Chiba University Graduate School of Medicine, Chiba University Hospital, Kazusa DNA Research Institute, The University of Tokyo, Kyoto University, and International University of Welfare and Health School of Medicine aimed to shed light on these questions by investigating the molecular mechanisms of subcutaneous fat dysfunction in WS. On October 3, 2023, their research paper was published in Aging’s Volume 15, Issue 19, entitled, “Senescence-associated inflammation and inhibition of adipogenesis in subcutaneous fat in Werner syndrome.”

“[…] research on WS is important as it can provide insights into the pathogenesis and development of treatments not only for WS but also for general age-related diseases [5].”

The Study

The researchers analyzed subcutaneous fat samples from four Japanese patients with WS and compared them with samples from healthy individuals. They found that WS subcutaneous fat cells showed signs of cellular senescence, which is a state of irreversible growth arrest that occurs when cells are exposed to stress or damage. Senescent cells secrete inflammatory molecules that can harm neighboring cells and tissues, known as senescence-associated secretory phenotype, or SASP.

The study also revealed that WS subcutaneous fat cells had impaired adipogenesis, which is the ability to differentiate into mature fat cells that can store lipids and secrete hormones. This was associated with reduced expression of genes involved in insulin signaling and lipid metabolism, such as IRS1, PI3K, AKT, and SREBP1. Moreover, the researchers found that rapamycin, a drug that inhibits a protein called mTOR that regulates cell growth and metabolism, could partially restore insulin signaling and adipogenesis in WS subcutaneous fat cells.

“These results suggest that rapamycin rescues cellular senescence and insulin resistance in WSVF [WS subcutaneous adipose tissues], and extends the lifespan of the WS model in vivo.”

Their findings suggest that senescence-associated inflammation and inhibition of adipogenesis play a role in subcutaneous fat reduction and dysfunction in WS, which may contribute to insulin resistance and metabolic disorders. This study also provides evidence that targeting mTOR with rapamycin or other drugs may have therapeutic potential for improving subcutaneous fat function and metabolic health in WS patients.

Conclusions

This study is one of the first to explore the molecular mechanisms of subcutaneous fat dysfunction in WS using human samples. It adds to the growing body of research on the role of senescence and inflammation in aging and age-related diseases. It also highlights the importance of subcutaneous fat as a key metabolic organ that affects not only body shape but also systemic health.

“Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.”

Click here to read the full study published in Aging.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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How Cognitive Reserve Can Help You Sleep Better and Think Sharper

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In a new study, researchers investigated the association between sleep, cognitive reserve and cognition in older adults.

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Sleep is vital for our health and well-being, but as we age, we tend to experience less and less of it. In particular, we lose some of the deep sleep stages, known as slow wave sleep (SWS), that are crucial for memory consolidation and brain maintenance. This can affect cognitive performance and increase our risk of developing dementia.

Not everyone is equally vulnerable to the negative effects of poor sleep quality. Some people seem to be more resilient and able to cope with less SWS without compromising their mental abilities. What makes them different? One possible factor is cognitive reserve (CR).

CR is a concept that refers to the brain’s ability to adapt and compensate for age-related changes or brain damage. It is influenced by various aspects of our life experiences, such as education, occupation, leisure activities, social interactions, and mental stimulation. People with higher CR are thought to have more efficient brain networks, more cognitive strategies, and more brain reserve (i.e., more neurons and connections) that can buffer the impact of aging or pathology on cognition.

In a new study, researchers Valentin Ourry, Stéphane Rehel, Claire André, Alison Mary, Léo Paly, Marion Delarue, Florence Requier, Anne Hendy, Fabienne Collette, Natalie L. Marchant, Francesca Felisatti, Cassandre Palix, Denis Vivien, Vincent de la Sayette, Gaël Chételat, Julie Gonneaud, and Géraldine Rauchs from Normandie University, UNI – ULB Neuroscience Institute, University of Liege, University College London, and CHU de Caen aimed to identify individuals in whom sleep disturbances might have greater behavioral consequences. On September 28, 2023, their research paper was published in Aging’s Volume 15, Issue 18, entitled, “Effect of cognitive reserve on the association between slow wave sleep and cognition in community-dwelling older adults.”

The Study

The researchers investigated whether CR could modulate the association between SWS and cognition in older adults. The researchers recruited 135 cognitively intact older adults (mean age: 69.4 years) from the Age-Well randomized controlled trial and measured their sleep quality using polysomnography — a technique that records brain waves, eye movements, muscle activity, and other physiological signals during sleep. They also assessed their cognitive performance using neuropsychological tests that evaluated executive function (i.e., the ability to plan, organize, monitor, and control one’s behavior) and episodic memory (i.e., the ability to remember personal events and experiences).

To estimate CR, the researchers used two measures of cognitive engagement throughout life: a questionnaire that asked about the frequency and diversity of participation in various activities (such as reading, playing games, learning languages, etc.) in different age periods; and a composite score based on the highest level of education attained, the complexity of the main occupation held, and the current cognitive activity level.

The results showed that SWS was positively associated with episodic memory performance, meaning that participants who had more SWS tended to have better memory scores. However, this association was not observed for executive function performance. CR proxies modulated the associations between SWS and both executive and episodic memory performance. Specifically, participants with higher CR were able to maintain cognitive performance despite low amounts of SWS, whereas participants with lower CR showed a steeper decline in performance as SWS decreased.

“This study provides the first evidence that CR may protect against the deleterious effects of age-related sleep changes on cognition.”

Conclusions

The study suggests that engaging in cognitively stimulating activities throughout life may enhance one’s ability to cope with less SWS without compromising one’s mental abilities. It also highlights the importance of considering individual differences in CR when evaluating the impact of sleep quality on cognition in older adults.

The authors were forthcoming about limitations of their study, such as the cross-sectional design that does not allow causal inferences, the relatively small sample size that limits the generalizability of the findings, and the use of proxy measures that may not capture all aspects of CR. They also point out some directions for future research, such as exploring the underlying mechanisms of how CR influences sleep-cognition relationships, examining whether CR can also modulate the effects of other sleep parameters (such as sleep duration or fragmentation) on cognition, and investigating whether interventions that target sleep quality or CR can improve cognitive outcomes in older adults.

In conclusion, this study suggests that CR may be an important factor that can help us sleep better and think sharper as we age. It also encourages us to keep our brains active and challenged throughout our lives, as this may benefit not only our cognitive functioning but also our sleep quality.

“These findings are important to understand the factors promoting successful aging and suggest that the deleterious impact of sleep disturbances could be counteracted by an enriched lifestyle. This will help to design non-pharmacological interventions to promote successful aging and counter age-related sleep changes.”

Click here to read the full study published in Aging.

Interested in reading more about cognitive reserve and aging? Click here.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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The Role of R-loops in Neuronal Aging

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In a new editorial, researcher Hana Hall discusses the role of R-loops in neuronal aging and neurodegeneration. 

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R-loops are structures that form when the nascent RNA hybridizes with the template DNA strand, displacing the non-template strand. In other words, R-loops are like temporary tangles in our DNA where a new RNA molecule forms by copying one of the DNA strands and pushes aside the other DNA strand. Nascent RNA refers to the newly synthesized RNA molecule that is produced during the process of transcription. In addition to transcription, R-loops are involved in various biological processes, such as splicing, DNA repair and chromatin remodeling. However, when R-loop homeostasis is disrupted, they can also cause transcriptional impairment, genome instability and cellular dysfunction.

“R-loops have been shown and studied in a wide range of organisms and while they have important regulatory roles, persistent R-loops can be detrimental to cell function and survival, having been closely linked to both gene expression dysregulation and increased genome instability.”

In a new editorial paper, researcher Hana Hall from the Purdue Institute for Integrative Neuroscience at Purdue University discusses the role of R-loops in neuronal aging and neurodegeneration. On September 13, 2023, her editorial was published in Aging’s Volume 15, Issue 17, and entitled, “R-loops in neuronal aging.” Hall summarizes her recent study and the current knowledge on how R-loop levels change during aging, how they affect gene expression and neuronal function, and how they are regulated by different factors.

“In our recent study, we demonstrated that R-loops accumulate in fly PR [photoreceptor] neurons by middle age and significantly increase into late-life stages [5].”

The Editorial

According to Hall, R-loop levels increase with age in different organisms and tissues, including neurons. This could be due to several reasons, such as reduced expression or activity of R-loop resolving enzymes (e.g., Top3β, RNase H1), increased transcriptional activity or stress, or impaired DNA repair mechanisms. Hall also highlighted that R-loop accumulation is associated with decreased expression of long and highly expressed genes, which are enriched for neuronal functions. This could lead to impaired neuronal activity and communication, as well as increased vulnerability to neurodegenerative diseases.

“Our study provides first evidence of R-loop accumulation in aging neurons and a contributing role in loss of neuronal function during aging.”

Hall further discussed how R-loop homeostasis is modulated by various factors, such as chromatin structure, epigenetic modifications, RNA-binding proteins, and non-coding RNAs. She also mentioned some potential therapeutic strategies to restore R-loop balance in aging neurons, such as overexpressing or delivering R-loop resolving enzymes, modulating chromatin accessibility or targeting specific R-loop forming genes.

Conclusions

Hall concluded that R-loops are important players in neuronal aging and neurodegeneration, and that more studies are needed to understand their molecular mechanisms and functional consequences. She also suggested that R-loop mapping could be used as a biomarker to monitor neuronal health and disease progression. This editorial provides a comprehensive overview of the current knowledge of R-loops in neuronal aging, and highlights the challenges and opportunities for future research. 

“Undoubtedly, R-loops are at the crossroads of several hallmarks of aging, namely transcriptional stress, genome instability, and chronic immune response. Targeting R-loop levels thus may help restore these pathways to a normal/healthy state and slow down or prevent the onset of age-dependent neurodegenerative diseases.”

Click here to read the full editorial published in Aging.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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The Impact of Age on Melanoma: Insights from Recent Research

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In a new editorial, researchers delve into the intricate dynamics of melanoma and aim to illuminate differences in age-related incidence, prognosis and treatment.

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In the realm of cancer research, one persistent trend has emerged — the incidence of invasive melanoma rises steadily with advancing age. While this insidious disease remains rare in children and adolescents, it progressively asserts its presence as individuals grow older. The connection between age and melanoma incidence persists around the world, albeit with varying rates in different countries. 

Australia has the highest melanoma rates in the world. According to the Melanoma Institute Australia, every 30 minutes an Australian is diagnosed with melanoma and every 6 hours an Australian dies from it. Thankfully, research is making a difference. In the last decade, the 5-year overall survival rate for advanced melanoma has increased from less than 10% to more than 50%. In 2011, melanoma was Australia’s 7th most deadly cancer. In 2021, melanoma was Australia’s 11th most deadly cancer.

Figure 1. Melanoma incidence (A) and mortality (B) according to age [2].

In a new editorial paper, researchers John F. Thompson and Gabrielle J. Williams from the Melanoma Institute Australia at The University of Sydney discuss the intricacies of how age influences different varieties of melanoma incidence, prognosis and treatment. On August 17, 2023, their editorial was published in Aging’s Volume 15, Issue 16, entitled, “The effect of age on melanoma incidence and prognosis.”

Understanding Melanoma Subtypes

The researchers point out that while invasive melanoma is at the forefront of discussion, non-invasive “melanoma in situ” (MIS) follows a similar age-related pattern of increase. MIS, often exemplified by lentigo maligna (LM), results from chronic, accumulated exposure to ultraviolet light. The progression from LM to invasive lentigo maligna melanoma (LMM) occurs at an estimated rate of 3.5% per year, with an average transition period of 28.3 years.

Older patients are more prone to another unique subtype known as desmoplastic melanoma, linked to chronic sun exposure and frequently affects the head or neck. While desmoplastic melanomas have a somewhat higher local recurrence rate, the majority of invasive melanomas in elderly patients exhibit features associated with poorer prognosis, including ulceration, higher mitotic rates and increased Breslow thickness.

Melanoma Biopsies & Treatment Options

Patients with high-risk primary melanomas are often recommended for a sentinel lymph node biopsy (SLNB) to assess the presence of metastatic melanoma cells in regional lymph nodes—a pivotal prognostic factor. Strikingly, the likelihood of a positive SLNB result decreases with age. However, as age advances, the risk of death due to melanoma’s spread to distant sites increases, leaving researchers grappling with the mysteries of why these phenomena occur.

Current treatments for SLN-positive melanoma patients include immunotherapy and targeted therapy. Immunotherapy agents like ipilimumab, pembrolizumab and nivolumab have shown promise in treating melanoma. While initial clinical trials excluded the very young and elderly, subsequent non-randomized studies have revealed that these agents are similarly effective in older patients, with comparable adverse event profiles. However, the efficacy of these therapies in children and adolescents remains uncertain.

Targeted therapies focusing on BRAF mutations, including vemurafenib and dabrafenib, have been employed, particularly in younger patients who exhibit a higher prevalence of BRAF positivity. Response rates are significant but often followed by resistance. Interestingly, these therapies appear to exhibit similar efficacy and safety profiles in older patients, offering a glimmer of hope for this demographic.

In older melanoma patients with brain metastases, radiation therapy has historically played a crucial role, offering alternatives to surgical excision. Studies have revealed that both whole-brain radiotherapy and stereotactic radiotherapy are equally effective in patients aged 70-90 as in younger groups. With the advent of immunotherapy and targeted therapies, combining localized radiation with systemic treatment is becoming an option, particularly in older patients, offering the potential for similar benefits as seen in younger cohorts.

Conclusions & Future Directions

The data presented in this editorial underscore a stark reality — melanoma’s impact escalates with age. Patterns of the disease differ significantly in older age groups, with increasing rates of metastasis and death. However, standard forms of melanoma management, including surgery, radiation therapy and newer systemic therapies, have proven to be as effective and safe in older patients as in their younger counterparts. This knowledge serves as a beacon of hope, offering solace and potential avenues for treatment in the face of this disease.

In closing, the critical role of research and continued investigation cannot be overstated. Further exploration of age-related nuances in melanoma will undoubtedly uncover new insights and lead to more tailored and effective treatments for all patients, regardless of their age.

Click here to read the full editorial published in Aging.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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Dry Eyes? It May be Immune Infiltration in Aging Lacrimal Glands

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In a new editorial, researchers from Baylor College of Medicine artfully discuss the immune system’s role in dry eye disease. 

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The lacrimal gland, found in the upper outer part of the eye’s hollow area, is an important gland that makes tears to protect the eye from infections. It’s split into two parts: one near the inside of the eyelid that can be seen when the eyelid is flipped, and another part with ducts lower in the eye that connects to its counterpart. In their fully functioning status, these ducts release fluid onto the surface of the eye. As humans age (especially women), the lacrimal gland gradually becomes infiltrated by aberrant immune cells and can ultimately lead to an uncomfortable condition known as dry eye disease.

“Burning and redness in the eyes, grittiness and blurry vision make life miserable and currently, eye drops with a variety of lubricant components and in the most severe cases, immunosuppressors, are the only therapies approved for this disease.”

In a well-written new editorial paper, researchers Claudia M. Trujillo-Vargas and Cintia S. de Paiva from the Department of Ophthalmology at Baylor College of Medicine artfully discuss their recent studies which shed light on the immune system’s role in dry eye disease. On August 11, 2023, their editorial was published in Aging’s Volume 15, Issue 15, entitled, “Our search of immune invaders in the aged lacrimal gland.”

Editorial Summary

The authors write that their research group has been dedicated to investigating the changes that occur in the lacrimal gland due to aging and focus on immunopathological alterations. Due to limited human samples, their studies have centered on understanding the infiltration of lymphocytes, specifically B and T cells, in aged mice’s lacrimal glands. This infiltration has been linked to increased dysfunction of the ocular surface. 

“In the search of mechanisms that can counteract the effects of the overwhelming immune infiltration, we started characterizing one of the main players of immune tolerance, the thymic-derived T regulatory cells (Tregs).”

The researchers and their team have a particular interest in thymic-derived T regulatory cells (Tregs), which play a key role in immune tolerance. Paradoxically, in the aged glands, these Tregs, while exhibiting markers for their suppressive function, display heightened differentiation, infiltrate the tissue, produce inflammatory cytokines, and demonstrate impaired suppressive capabilities. When transferred to immunodeficient recipients, these dysfunctional Tregs replicate lacrimal gland pathology. 

Aged lacrimal glands contain highly differentiated CD4+ T cells of the Th1 and Th17 phenotypes, which exhibit exhaustion and immunopathological features. This environment hampers Tregs’ ability to suppress immune responses. There’s also an increase in naïve CD4+ T cells and IgD+ B cells, suggesting a unique environment for the recruitment of inexperienced immune cells in the gland.

Ectopic lymphoid structures, resembling those found in aged tissues, are observed in the lacrimal gland, potentially contributing to immune dysregulation. Despite the concept of immune cells being unwelcome invaders, the lacrimal gland relies on immune cell influx for surveillance purposes, as it is highly vascularized. Nonetheless, with age, immune cell infiltration intensifies, accompanied by fibrosis, duct issues and gland atrophy. Interestingly, antigen-presenting cells diminish, adding to the peculiar immune environment.

In their running analogy to the movie “Men in Black,” the researchers explain that they are seeking effective therapies, akin to the “noisy crickets,” to combat this pathological immune infiltration. They’re investigating differentially expressed genes in the aged gland, focusing on Tregs expressing Il1r2, CD81 and Tbx21, and B cells showing increased CD79a/b expression. The researchers are also exploring the gut microbiota’s role in ocular barrier disruption and dry eye disease in mice. This could lead to more cost-effective microbial treatments for dry eye disease in humans. However, the effectiveness of these therapies in impeding lymphocyte infiltration in aged lacrimal glands remains uncertain.

Conclusions & Future Directions

In conclusion, their editorial provides valuable insights into the role of the lacrimal gland in the immune system and how it could be used to develop new treatments for dry eyes and other age-related eye diseases. The authors’ research has shown that aged lacrimal glands are infiltrated not only by highly differentiated B but also T cells. This landscape is associated with increased ocular surface dysfunction. The authors suggest that this information could be used to develop new therapies for age-related eye diseases.

Considering the rising pollution and screen dependence in the past decade, the researchers predict an increase in severely damaged lacrimal glands in the elderly. This environment could foster the development of ectopic lymphoid structures, potentially leading to a higher prevalence of dry eye disease. As such, interventions will be required to mitigate the immune damage to the lacrimal gland. Ultimately, protecting the lacrimal glands from the consequences of immune dysregulation is a critical goal.

“Unquestionably, more than ‘fancy sunglasses’ would be needed to hinder the ‘carbonizing’ immune damage in the gland. Thus, Yes! We certainly need to protect our lacrimal glands from the scum of our own immune universe!”

Click here to read the full editorial published in Aging.

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Aging is an open-access, traditional, peer-reviewed journal that has published high-impact papers in all fields of aging research since 2009. All papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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Navigating the Frailty Factor in Atrial Fibrillation Management

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In a new editorial, researchers discuss the impact of frailty on clinical decision-making in managing patients with atrial fibrillation and the prescription of oral anticoagulants.

Atrial fibrillation (AF) is a type of heart arrhythmia that occurs when the ​​heart’s electrical signals become irregular. This condition can increase the risk of stroke and heart failure, and becomes more common in older adults. Frailty is another condition that coincides with aging. Frailty encompasses an accumulation of deficits and can be defined as decreased physical function and resilience. For a significant proportion of the elderly population, both of these conditions coexist. This convergence can lead to additional health issues and further complicate the clinical landscape for aging individuals. 

“The impact of frailty on outcomes has not been previously well characterized in populations with AF.”

Studies on frailty and its overall impact on patients with AF are needed. In a new editorial paper, researchers Stephanie L. Harrison, Søren P. Johnsen and Gregory Y.H. Lip from Liverpool John Moores University and Liverpool Heart and Chest Hospital discuss some of the existing studies assessing frailty and AF in terms of patient outcomes and clinical decision-making. The researchers also discuss recommendations for clinical management of AF and frailty patients and include suggestions for future studies. On July 19, 2023, their editorial was published in Aging’s Volume 15, Issue 14, entitled, “The impact of frailty on the management of atrial fibrillation.”

Oral Anticoagulants for AF With Frailty: Yay or Nay?

Oral anticoagulants (OACs) are often prescribed to AF patients, as OACs aid in reducing blood clots and the risk of stroke. However, frailty patients are more susceptible to falls and therefore, more susceptible to bleeding risk. The prevention of blood clots is less than ideal for wound healing and can lead to impaired tissue repair, increased risk of infection and prolonged recovery times. Has frailty status impacted clinical decision-making when it comes to the prescription of OACs for AF patients?

“The impact of frailty on clinical decision making for managing patients with AF such as the prescription of oral anticoagulants (OACs) is unclear.”

In an effort to begin answering this question, the authors of this editorial reviewed a number of studies on frailty and AF. Some cross-sectional analyses revealed a significant association between frailty status and the prescription of OACs, while other studies found no such association. The authors explain that these dueling results may be due to differences in study populations, the tools/methods used to assess frailty and the timing of when the studies were conducted. The prescription of anticoagulants increased when a new class of OACs was introduced to the market.

Non-vitamin K antagonist oral anticoagulants (NOACs) were first introduced in the early 2010s. They are a class of drugs with significant advantages over traditional OACs, including less off-target effects, more predictable pharmacokinetics and a more targeted mechanism of action — making them a safer option for use in combination with other drugs. Notably, certain NOACs have specific reversal agents available, which can be used to rapidly reverse their anticoagulant effect in case of emergency. International guidelines recommended their use as a first-line treatment to reduce the risk of stroke in AF patients.

“Frailty alone should not be reason to withhold oral anticoagulation in patients with AF. In patients with frailty, the benefits of oral anticoagulation outweigh the small absolute risk of bleeding [6].”

Conclusions & Future Directions

The authors close the editorial by stating that additional research is needed to understand how frailty impacts clinical decision-making for the management of atrial fibrillation. They strongly suggest that frailty not be the sole reason AF patients are not prescribed potentially life-saving oral anticoagulants. There are more sensitive options available today, such as NOACs, that can potentially mitigate the drawbacks of anticoagulants for people with frailty. The authors also emphasize that pre-frailty assessments should be conducted for AF patients in order to reduce treatment risk and optimize the management of this condition.

“Assessment of pre-frailty in patients with AF and the development of strategies to address potentially modifiable components of pre-frailty to reduce the risk of frailty progression could have important implications to optimize care.”

Click here to read the full editorial published in Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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Exploring the Impact of Cognitive Reserve on Cognitive Resilience

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In a new editorial, researchers discuss their recent study investigating the effect that cognitive reserve has on brain integrity and cognitive resilience.

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Why do some individuals maintain cognitive abilities throughout their lifespan and others do not? The better question may be: How can certain individuals preserve their cognitive abilities and delay the onset of dementia despite the presence of significant neuropathologies that would otherwise suggest cognitive decline? This question remains unanswered.

“What contributes to this ‘resilience’ [3], that is why some successfully cope with progressive neuropathology while others cannot tolerate the same level of neurodegeneration, is not fully understood.”

This unanswered question has driven researchers to consider the idea of “cognitive reserve.” The rather new concept of cognitive reserve suggests that certain factors, such as engaging in education, mental stimulation and challenging activities, can create a buffer against cognitive decline and delay the onset of cognitive impairment or dementia. Researchers continue to study cognitive reserve to better understand its mechanisms and potential implications for maintaining brain health and designing effective interventions.

In a new editorial paper, researchers Monica E. Nelson, Ross Andel and Jakub Hort from the University of South Florida’s​​ School of Aging Studies discussed the outcomes, lessons and future implications of their previous 2022 study. The team examined the influence of cognitive reserve proxies on the relationship between brain integrity and cognition. On July 14, 2023, their editorial was published in Aging’s Volume 15, Issue 13, entitled, “Cognitive reserve, neuropathology, and progression towards Alzheimer’s disease.”

Cognitive Reserve’s Effect on Brain Integrity and Cognitive Performance

In their 2022 study, a total 570 older adult participants were assessed from the Czech Brain Aging Study (a longitudinal cohort study from two memory clinics in the Czech Republic). Most of the participants (n = 457) were without dementia (including those with subjective cognitive decline and amnestic mild cognitive impairment) and the remaining participants were with dementia syndrome (n = 113). The researchers examined the influence of education and occupational position (cognitive reserve proxies) on the relationship between the participants’ hippocampal or total gray matter volume and cognitive performance. Measurements included brain volume, executive control, language, memory, attention/working memory, and visuospatial skills.

“[…] we assessed the inter-link between cognitive reserve, neuropathology, and cognitive functioning among participants with subjective cognitive decline, mild cognitive impairment, and dementia.”

The team found that the association between brain volume and cognitive performance varies based on cognitive reserve. Findings showed that a higher education and occupational position magnified the associations between brain volume and cognitive performance in participants without dementia. In participants with dementia, higher education decreased the associations between brain volume and visuospatial skills. Overall, the results showed that cognitive reserve affects the relationship between brain volume and cognitive performance, with greater cognitive reserve related to a stronger link before dementia diagnosis and a weaker link after.

Future Directions 

In their subsequent editorial, the researchers were forthcoming about limitations of this study and addressed key opportunities for future studies. Limitations were identified as the use of a relatively homogeneous sample population, the absence of the use of biomarkers in diagnosis and the cross sectional design. Cross-sectional studies may not fully capture disease-related changes in neuropathology and could present a distorted view of the linkages between cognitive reserve, neuropathology and cognitive outcomes. The authors advocate for conducting longitudinal studies to track how cognitive reserve operates in individuals as they progress from normal to dementia. 

Additionally, the team wrote that future studies would be improved by investigating a range of Alzheimer’s disease biomarkers, such as beta-amyloid and tau, individually and together, to understand how they influence the associations between cognitive reserve, brain health and cognition. Different biomarkers may lead to varied results in how cognitive reserve moderates these associations. And finally, future studies should also assess older adults across the cognitive spectrum to determine when cognitive reserve is protective against brain health decline and neuropathology, and when its effectiveness diminishes. Some researchers have suggested a U-shaped relationship to explain mixed findings in different studies.

“Even though our study represents one of the first to come from Eastern Europe [4], future work should be conducted in additional populations, representing geographic, racial, and socioeconomic diversity.”

Implications

The potential impact of this research may be important, as it could lead to the development of effective interventions and strategies to preserve cognitive abilities and delay the onset of dementia. By gaining a deeper understanding of cognitive reserve and its mechanisms, we can take steps to promote brain health throughout life, potentially reducing the burden of dementia on individuals, communities and society overall.

As research continues in this field, it is clear that cognitive reserve holds great promise for unlocking the secrets of cognitive resilience and paving the way for healthier aging and improved quality of life for older adults. By addressing the limitations of current studies and exploring new avenues of investigation, we move closer to finding answers to the vital question of how some individuals maintain their cognitive abilities despite the presence of significant neuropathologies, while others do not.

“By assessing cognitive reserve in distinct populations, a more complete understanding of how cognitive reserve relates to neuropathology and cognition and whether these associations may be affected by distinct macro-level contextual differences among populations can be established. Disentangling these complex relationships may provide a critical step in reducing the impact of dementia on society.”

Click here to read the full editorial published by Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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Can a Leaky Gut Lead to Alzheimer’s Disease?

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In a new editorial, researchers explore how a leaky gut can lead to Alzheimer’s disease using the Seed and Soil Model of Neurocognitive Disorders to explain.

New research continues to illuminate the far-reaching implications of the gut microbiome and its crucial role in our overall health. The term “gut dysbiosis” refers to an imbalance of healthy and unhealthy microbes in the gastrointestinal tract. Repercussions of gut dysbiosis are not only limited to innocuous discomfort—it can lead to immune dysregulation and trigger a cascade of various disease states. 

In a new editorial paper, researchers Chun-Che Hung, Kristi M. Crowe-White and Ian M. McDonough from Chang Gung University and The University of Alabama discuss the relationship between gut dysbiosis and neurocognitive disorders such as Alzheimer’s disease (AD). Their editorial was published in Aging’s Volume 15, Issue 12, on June 19, 2023, entitled, “A seed and soil model of gut dysbiosis in Alzheimer’s disease.”

“[…] recent research has demonstrated a crucial role of gut microbiota in the etiopathogenesis of AD [Alzheimer’s disease] that offers a new window into possible origins and consequences of AD through interactions between gut microbiota and the central nervous system, known as the ‘microbiota-gutbrain axis’ [1].”

The Seed and Soil Model of Neurocognitive Disorders

The “Seed and Soil Model” in biology was first used in an attempt to describe why some individuals who are predisposed to developing neurocognitive disorders do not ever develop them. As the researchers wrote in their editorial, the “seeds” in this analogy represent genetic predispositions or a family history of a particular disease state. The “soil” represents the external environment that either enables or disables the expression of these seeds. This external environment can be influenced by behavioral and/or lifestyle factors. Although this model did not originally include the microbiota-gut-brain axis, the authors of this editorial are now applying it.

Interestingly, the researchers here have related the “leaky gut” phenomenon of gut dysbiosis to Alzheimer’s disease (AD). A leaky gut, plainly described as increased intestinal permeability, is a condition where the lining of the intestine becomes more porous. This allows larger molecules and toxins to pass through into the bloodstream—opening the door to potential inflammation and various health problems. 

Metabolites involved with gut leakiness have previously been linked to increased permeability of the blood-brain barrier (BBB). The opening of the BBB allows bacterial endotoxins to travel from the gut to the brain environment. This can increase inflammation within the system. The authors propose that gut leakiness, through the Seed and Soil Model, may explain why some people predisposed to AD realize the disease, while those without gut dysbiosis may not.

“According to the Seed and Soil Model of Neurocognitive Disorders, this translocation would create a toxic microenvironment in the brain vulnerable to pathogenesis, especially for those with a genetic predisposition to AD.”

Conclusion

“According to the Seed and Soil Model of Neurocognitive Disorders, environmental and behavioral patterns can influence the balance of neuroprotection vs. toxicity of the brain’s micro-environment.”

In sum, emerging research continues to shed light on the significance of the gut microbiome and its connection to our overall health. The editorial by Hung, Crowe-White and McDonough explores the relationship between gut dysbiosis and neurocognitive disorders, particularly Alzheimer’s disease, through the lens of the Seed and Soil Model of Neurocognitive Disorders. By considering the impact of leaky gut and the translocation of bacterial endotoxins on the brain, the authors propose that gut dysbiosis may contribute to the pathogenesis of AD, particularly in individuals with a genetic predisposition. This perspective opens new avenues for understanding the complex interactions within the microbiota-gut-brain axis and provides insights into ways to potentially stave off cognitive decline with diet and lifestyle interventions.

“Here, we extend the model to better understand how the microbiota-gut-brain axis may play a causal role in the development of AD. However, more research is needed to test additional hypotheses of the model.”

Click here to read the full research paper published by Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

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The Impact of Age, Sex, CMV, and Smoking on Circulating Immune Cells

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In a new study, researchers investigated associations between circulating immune cells and age, sex, CMV infection, and smoking.

The Impact of Age, Sex, CMV, and Smoking on Circulating Immune Cells

As we age, our immune system undergoes changes that influence our susceptibility to various diseases. Certain factors, such as smoking, viruses, age, and sex can have differential impacts on our various circulating immune cells. How changes to these immune cells contribute to cardiovascular disease and other age-related diseases is not yet fully understood. More research is needed to fully understand the underlying mechanisms and implications. 

“Understanding the composition of circulating immune cells with aging and the underlying biologic mechanisms driving aging may provide molecular targets to slow the aging process and reduce age-related disease.”

In a new study, researchers Yuan Fang, Margaret F. Doyle, Jiachen Chen, Jesse Mez, Claudia L. Satizabal, Michael L. Alosco, Wei Qiao Qiu, Kathryn L. Lunetta, and Joanne M. Murabito from Boston University, Boston Medical Center, University of Vermont, and University of Texas Health Science Center aimed to characterize the circulating innate and adaptive immune system by profiling immune cell phenotypes from a community-based cohort. Their research paper was published in Aging’s Volume 15, Issue 10, on April 27, 2023, entitled, “Circulating immune cell phenotypes are associated with age, sex, CMV, and smoking status in the Framingham Heart Study offspring participants.”

“We hypothesize that we will identify immune cell phenotype and ARIP [age-related immune phenotype] measure associations with CMV serostatus, age, and sex, as well as associations with cardiovascular risk factors.”

The Study and Participant Characteristics

The Framingham Heart Study (FHS) is a community-based prospective cohort study that began in 1948. It initially recruited 5,209 primarily white American adults of European ancestry as the Original cohort. In 1971, the Offspring cohort was established, consisting of the children of the Original cohort and their spouses. The Offspring participants have been examined every 4-8 years since enrollment. 

For this study, 1,332 Offspring participants who attended exam seven (1998 to 2001) and had two or more vials of stored peripheral blood mononuclear cells (PBMCs) were identified. From this group, a study sample of 996 dementia-free individuals, aged 40 years and older, was selected. This cohort had a mean age of 62 years, with 52% representing males. All participants provided written informed consent, and the FHS exams were approved by the Institutional Review Board at Boston University Medical Center.

The research team used cryopreserved cell samples from the study participants to conduct comprehensive analyses of 116 circulating immune cell phenotypes, including subtypes of CD4 and CD8 T cells, B cells, NK cells, and monocytes. These subsets were further categorized based on specific surface markers to provide a detailed characterization of the immune cell populations.

The Results

Significant associations between circulating immune cell phenotypes and age, sex, a common virus, and smoking were revealed in this study. With advancing age, researchers saw a decline in the overall number of immune cells, as well as alterations in the distribution of different immune cell subsets. Notably, older individuals exhibited a higher proportion of memory T cells and a lower proportion of naive T cells, suggesting a shift towards a more experienced immune profile. Furthermore, females exhibited a higher abundance of immune cells compared to males, which may contribute to their generally stronger immune responses.

Cytomegalovirus (CMV), a common herpesvirus, can have a profound impact on the immune system. The study found that CMV seropositivity was associated with distinct alterations in immune cell phenotypes. CMV-positive individuals displayed higher numbers of late-stage differentiated effector memory T cells, which are indicative of previous exposure to CMV. This observation suggests that CMV infection contributes to the age-related changes in immune cell populations.

Smoking has long been recognized as a detrimental habit that affects overall health, including the immune system. This study uncovered compelling evidence linking smoking status to immune cell phenotypes. Smokers exhibited a higher proportion of pro-inflammatory immune cells, such as activated T cells and pro-inflammatory monocytes, while non-smokers had a higher proportion of regulatory T cells that help maintain immune balance. These findings emphasize the detrimental impact of smoking on immune cell profiles and further underscore the importance of smoking cessation.

“Importantly, we did not identify significant immune cell associations with other risk factors, such as body mass index, prevalent cardiovascular disease, hypertension or diabetes.”

Conclusions

“Our observations confirm and extend known associations of immune cell subtypes with CMV and age that show a shift from a naïve phenotype towards an exhausted phenotype. We report sex differences, with males exhibiting a more exhausted, cytotoxic landscape than females. We identified associations between CD8 exhausted cells and B cell subsets, but not overall B cells, with smoking status.” 

This research provides valuable insights into the relationship between circulating immune cell phenotypes and age, sex, CMV infection, and smoking status. In conclusion, the team did not find significant associations between these immune cells and cardiovascular risk factors. They did find some weak associations with cardiovascular disease, diabetes and hypertension. The findings contribute to our understanding of age-related changes in the immune system and highlight the impact of lifestyle factors on immune health. By unraveling the complex interplay between these variables, this study paves the way for future research on interventions and strategies to support healthy immune aging.

“While further studies in larger, more diverse sample[s] and more than one time point with immunophenotypic data are needed, this work will provide a valuable resource for future studies of the association of immune cell phenotypes and incident age-related disease.”

Click here to read the full research paper published by Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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Brain Aging Insights from Individuals Without Neurodegeneration

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The Trending With Impact series highlights Aging publications (listed by MEDLINE/PubMed as “Aging (Albany NY)” and “Aging-US” by Web of Science) that attract higher visibility among readers around the world online, in the news and on social media—beyond normal readership levels. Look for future science news about the latest trending publications here, and at Aging-US.com.

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A healthy brain continuously produces new proteins to support synaptic plasticity, maintain neuronal health, facilitate signaling pathways, produce neurotransmitters, enable neuroplasticity and adaptation, and meet its metabolic demands. These processes are essential for normal brain function, learning, memory, and overall cognitive abilities. Researchers believe that the dysregulation of proteins is at the core of brain aging. However, the exact recipe for protein dysregulation that leads to accelerated brain aging and neurodegenerative disorders has yet to be brought to light. 

Previous brain proteostasis (referring to the maintenance of protein homeostasis in brain cells) studies in individuals with Alzheimer’s disease (AD) pathology and age-related neuropathological changes have shown protein dysregulation leading to a buildup of amyloid plaques and neurofibrillary tangles. While these studies have greatly enhanced our knowledge of brain aging, gaps in our understanding remain. What proteomic characteristics do healthy brain aging individuals—without neurodegenerative disorders—have in common?

“To our knowledge, whole phosphoproteomes centered on the human brain aging without AD pathology are unavailable.”

In a new study, researchers Pol Andrés-Benito, Ignacio Íñigo-Marco, Marta Brullas, Margarita Carmona, José Antonio del Rio, Joaquín Fernández-Irigoyen, Enrique Santamaría, Mónica Povedano, and Isidro Ferrer from Bellvitge Institute for Biomedical Research, Universidad Pública de Navarra, Barcelona Institute for Science and Technology, and University of Barcelona aimed to shed light on the mechanisms underlying brain aging in the absence of AD pathology and age-related neuropathological changes. Their research paper was published on May 13, 2023, in Aging’s Volume 15, Issue 9, and entitled, “Proteostatic modulation in brain aging without associated Alzheimer’s disease-and age-related neuropathological changes.”

The Study

The production of new proteins is crucial for maintaining protein homeostasis in the brain. A post-translational modification used to maintain this homeostasis is protein phosphorylation. In this study, the researchers conducted proteomic and phosphoproteomic analyses of frontal cortex samples from the donor brains of deceased individuals between the ages of 30 and 85. These individuals had passed away due to non-neurological complications and were reported to have had full cognitive function. Individuals were divided into four groups: young group one (30–44), middle-aged group two (45-52), early-elderly group three (64–70), and late-elderly group four (75–85).

“​​We chose the FC [frontal cortex] because of its role in cognition and emotion and the abundant molecular information that permits comparison with other studies.”

Conventional label-free- and SWATH- (sequential window acquisition of all theoretical fragment ion spectra) mass spectrometry were used to assess the (phospho)proteomes of the frontal cortices from individuals in all four age groups. Immunohistochemistry and/or western blotting was/were also used to validate a subgroup of proteins. The researchers categorized deregulated proteins and phosphoproteins into eight clusters based on their age-dependent expression similarity (see paper for clusters). Interestingly, protein and phosphoprotein levels of the larger hierarchical clusters were stable until the age of 70 years. After 70, the late-elderly group showed significant decreased or increased expression of protein clusters one and seven, and major phosphorylation modifications occurred in clusters four and eight.

Results

The team then used multi-comparative analyses to categorize altered proteins and phosphoproteins as neuronal, astroglial, oligodendroglial, microglial, and endothelial. They observed a similar pattern among proteomic and phosphoproteomic alterations: major changes were related to neuronal cell populations across all four groups—and these changes were more pronounced with age. Cytoskeletal and membrane proteins accounted for the largest number of differentially-expressed proteins and phosphoproteins.

“Furthermore, main alterations in the proteome are associated with proteins specific to neuronal populations, rather than those found in other cell types in the brain.”

Their findings also revealed a decline in the expression of P20S α + β with aging, while the expression of P19S and immunoproteasome subunits LMP2 and LMP7 remained preserved. Notably, the expression levels of an autophagy component, ATG5, remained unchanged with age. Some mitochondrial membrane proteins showed altered levels at advanced ages, but key markers of mitochondrial function were preserved. These findings suggest a potential preservation of these pathways in advanced aging, contrasting with observations in neurodegenerative disorders. Additionally, reduced levels of GSK3α/β were observed, and the researchers point out that this decrease in GSK3α/β with age may be understood as protective against different age-related brain diseases.

Summary & Conclusion

“Therefore, our results fill the gap between brain ageing without ADNC [AD neuropathological changes], and cases with early and advanced stages of AD pathology.”

The researchers are forthcoming about limitations of this study. Given it is rare for old-aged individuals not to have neurological deficits, AD or other neuropathological changes, their main limitation was that each of the four groups included merely four individuals. Despite limitations, these findings contribute to our understanding of brain aging in the absence of AD pathology and age-related neuropathological changes. 

The study revealed that major changes in protein expression were primarily associated with neuronal cell populations and became more pronounced with age. The preservation of specific protein pathways, proteasome components, autophagy-related components, and mitochondrial markers in advanced aging individuals without neurodegenerative disorders suggests the presence of resilience mechanisms that protect against protein dysregulation and neurodegeneration. Overall, this research provides valuable insights into the proteomic characteristics of healthy brain aging and highlights potential targets for therapeutic interventions aimed at promoting healthy brain aging and preventing age-related neurodegenerative diseases. Further studies are necessary to elucidate the specific mechanisms underlying these proteomic alterations and their functional implications in brain aging.

“The present observations identify proteostatic changes, including different changes in the phosphoproteome in the human FC in brain aging in the rare subpopulation of old-aged individuals without neurological deficits, and not having ADNC and other neuropathological change in any region of the telencephalon.”

Click here to read the full research paper published by Aging.

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Aging is an open-access, peer-reviewed journal that has been publishing high-impact papers in all fields of aging research since 2009. These papers are available to readers (at no cost and free of subscription barriers) in bi-monthly issues at Aging-US.com.

Click here to subscribe to Aging publication updates.

For media inquiries, please contact [email protected].

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