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140 citation(s) found for "LeBrasseur, Nathan K".

Habitual physical activity and sedentary behavior among women with and without premenopausal bilateral oophorectomy: an exploratory study
Jahanian, Omid , Kapoor, Ekta , Rocca, Walter A. , Kantarci, Kejal, Morrow, Melissa M. , Fortune, Emma , Kantarci, Kejal , LeBrasseur, Nathan, Morrow, Melissa M , Kantarci, Kejal , Jahanian, Omid , Winham, Stacey J. , LeBrasseur, Nathan K. , Mielke, Michelle M.

Mayo Clinic

Menopause | July 15, 2025 | Volume: 32 | Issue: 9 | Pages: 829-837

10.1097/gme.0000000000002574 | PMID 40663581 Get It

Objective: To explore potential differences in physical activity and sedentary behavior volumes and patterns among postmenopausal women with and without premenopausal bilateral oophorectomy (PBO). Methods: Women with a history of PBO (n = 50) and age-matched postmenopausal referent women (n = 50) were recruited. Participants wore accelerometers on both ankles for 7 days. Volume metrics of sedentary behavior and physical activity, such as step counts, active time, and sedentary time, as well as the sedentary behavior and habitual physical activity distribution, and accumulation patterns, were quantified from the accelerometer data and compared between groups. Results: Metrics indicating volume of sedentary behavior and physical activity were not statistically different between groups. PBO was significantly associated with higher variability in stepping bout time ( P = 0.022), indicating a potentially more complex walking pattern. In addition, PBO was significantly associated with lower variability in sedentary break time ( P = 0.012), and lower activity time Gini index ( Z = −2.428, P = 0.015). This suggests that women with PBO may have broken up their sedentary time with shorter and less variable activity bouts, and because they had relatively shorter average daily active time, they might be at a higher risk of subsequent adverse health outcomes such as low bone mineral density. Conclusions: Although there were no differences in overall activity volume, some differences in activity patterns emerged between women with PBO and referent women. The study highlights the need for longitudinal research to understand how physical activity and sedentary behavior patterns evolve in postmenopausal women with a history of PBO.
Trends and Risk Factors for the Hospitalization of Older Adults Presenting to Emergency Departments After a Bed-Related Fall: A National Database Analysis
Tom, Andy , Navarro, Sergio M. , Spears, Grant M. , Schluttenhofer, Adam , Junker, Michelle S., Zietlow, John , Davis, R B, Palmer, Allyson K. , Bellolio, Fernanda , Park, Myung S., Junker, Michelle, Davis, Roderick, Bellolio, M Fernanda , Palmer, Allyson K , Navarro, Sergio Michael , Schluttenhofer, Adam , LeBrasseur, Nathan K.

Mayo Clinic

Journal of Clinical Medicine | July 15, 2025 | Volume: 14 | Issue: 14 | Pages: 5008

10.3390/jcm14145008 | PMID 40725700 Get It

Background/objectives: Falls are a leading cause of traumatic injury and hospitalization for adults over the age of 65. While common, bed-related falls are relatively understudied when compared to ambulatory falls. The aim of this study is to characterize the risk factors for the hospitalization of older adults presenting to U.S. emergency departments (EDs) after a fall from bed. Methods: This was a cross-sectional study using publicly available data from the U.S. Consumer Product Safety Commission’s National Electronic Injury Surveillance System (NEISS) from 2014 to 2023, including all adults over the age of 65 presenting to the NEISS’s participating EDs with bed-related fall injuries. We identified fall injuries using a keyword search of the NEISS narratives and determined how the fall occurred by manually reviewing a randomized 3% sample of the narratives. We summarized demographics and injury patterns with descriptive statistics. We constructed a multivariable logistic regression model to identify risk factors for hospitalization and used Poisson regression to assess temporal trends in fall incidence and hospital admissions. Results: An estimated average of 320,751 bed-related fall injuries presented to EDs annually from 2014 to 2023. ED visits increased by 2.85% per year, while hospital admissions rose by 5.67% per year (p < 0.001). The most common injury patterns were superficial injuries (contusions, abrasions, lacerations, avulsions, and punctures) (28.6%), fractures (21.7%), and internal injuries (including concussions) (21.6%). Most of the falls occurred while transitioning into or out of bed (34.4%) or falling out of bed (56.8%). Hospitalization was required in 34.1% of cases and was associated with male sex, medication use at time of injury, and fracture injuries. Conclusions: Bed-related falls and associated hospitalizations are increasing among older adults. ED providers should understand risk factors for hospitalization in these common injuries such as male sex, medication use at time of injury, and high-risk injury patterns. Additionally, prevention efforts should focus on helping older adults remain safely in bed and then assisting with transitions into or out of bed.
Biomarkers of Cellular Senescence in Type 2 Diabetes Mellitus
Hoong, Caroline Wei Shan , White, Thomas A. , Atkinson, Elizabeth J. , Tweed, Amanda, Sfeir, Jad , Khosla, Sundeep , Hoong, Caroline, Sfeir, Jad G , Khosla, Sundeep , Hoong, Caroline W S , Farr, Joshua N. , Monroe, David G. , White, Thomas A., Palmer, Allyson K. , LeBrasseur, Nathan K.

Mayo Clinic

Aging Cell | May 31, 2025 | Volume: 24 | Issue: 8 | Pages: No page available

10.1111/acel.70120 | PMID 40448295 Get It

ABSTRACT Although animal studies have linked cellular senescence to the pathogenesis and complications of type 2 diabetes mellitus (T2DM), there is a paucity of corroborating data in humans. Thus, we measured a previously validated marker for senescent cell burden in humans, T‐cell expression of p16 mRNA, along with additional biomarkers, to compare the senescence phenotypes of postmenopausal control (lean, N = 37) and T2DM ( N = 27) participants. To control for effects of obesity alone, we included a third group of obese but non‐diabetic women ( N = 29) who were matched for body mass index to the T2DM participants. In addition, given the increase in fracture risk in T2DM despite preserved or even increased bone mineral density, we related these senescence biomarkers in the T2DM participants to skeletal microarchitectural parameters. Relative to the lean participants, T‐cell p16 and p21 Cip1 expression was increased in the T2DM, but not the obese, non‐diabetic participants. Expression of p16 and p21 Cip1 was positively associated with HbA1c and an index of skin advanced glycation end‐products. T2DM was also associated with an increase in a number of SASP factors. Among participants with T2DM, women in the highest tertile for T‐cell expression of p16 had significantly reduced tibial cortical area and thickness as compared to those in the lower two tertiles. Overall, our studies link cellular senescence to metabolic and skeletal alterations in T2DM and point to the need for further studies evaluating the role of cellular senescence in mediating skeletal fragility, as well as potentially other complications in T2DM.
An unbiased cell-culture selection yields DNA aptamers as novel senescent cell-specific reagents
Jachim, Sarah K. , Prieto, Luis I. , Dugan, Maria , Maher, L. James , Pearson, Keenan S, Doherty, Caroline D, Wilbanks, Brandon A, III, Louis James Maher , Pearson, Keenan , Doherty, Caroline Lloyd , Wilbanks, Brandon , Baker, Darren J. , LeBrasseur, Nathan K.

Mayo Clinic

No container title available | March 19, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1101/2025.03.19.643361 | PMID 40166138 Get It

ABSTRACT Cellular senescence is an irreversible form of cell-cycle arrest caused by excessive stress or damage. While various biomarkers of cellular senescence have been proposed, there are currently no universal, stand-alone indicators of this condition. The field largely relies on the combined detection of multiple biomarkers to differentiate senescent cells from non-senescent cells. Here we introduce a new approach: unbiased cell culture selections to identify senescent cell-specific folded DNA aptamers from vast libraries of trillions of random 80-mer DNAs. Senescent mouse adult fibroblasts and their non-senescent counterparts were employed for selection. We demonstrate aptamer specificity for senescent mouse cells in culture, identify a form of fibronectin as the molecular target of two selected aptamers, show increased aptamer staining in naturally aged mouse tissues, and demonstrate decreased aptamer staining when p16 expressing cells are removed in a transgenic INK-ATTAC mouse model. This work demonstrates the value of unbiased cell-based selections to identify new senescence-specific DNA reagents.
Symposia Report of The Annual Biological Sciences Section Meeting of the Gerontological Society of America 2023, Tampa, Florida
Rogina, Blanka , Anderson, Rozalyn M. , Curan, Sean, Yousefzadeh, Matthew J. , Ghosh, Bhaswati, Duque, Gustavo , Howlett, Susan E. , Austad, Steven N. , Korfhage, Justin , Christensen, Kaare , Carey, James R. , Bell, Justice, Gomes, Ana P. , Dixit, Vishwa Deep , Sen, Payel , Imai, Shin‐ichiro , Valdez, Gregorio , Orr, Miranda E. , Jones, Leanne , Castillo-Azofeida, David, Bonaguidi, Michael A. , Suh, Yousin , Duncan, Francesca E. , C, Weigler G Perry, Burkewitz, Kristopher , Zhou, Kai , Bouhrara, Mustapha , Kolind, Shannon , Dean, Doug, Pálovics, Róbert , Niedernhofer, Laura J. , Fan, Rong , Bueckle, Andreas , Kapahi, Pankaj , Jiang, Nisi , Diaz, Jose , Mishra, Sidharth P. , Ralmundo, Nuno, Banarjee, Reema , Allsopp, Richard , Curran, Sean P. , Anderson, Rozalyn M , Curran, Sean P , Yousefzadeh, Matthew J , Duque, Gustavo , Howlett, Susan , Austad, Steven , Demuth, Ilja , Gerstorf, Denis , Abadir, Peter , Christensen, Kaare , Palmer, Allyson, Basisty, Nathan , de Cabo, Rafael , Sen, Payel , Baur, Joseph A , Duncan, Francesca E , Benjamini, Dan , Walker, Keenan A , Dean, Douglas C , Gladyshev, Vadim N , Fan, Rong , Sato, Shogo , Jiang, Nisi , Ashiqueali, Sarah A., Allsopp, Richard , Niedernhofer, Laura J , Kollind, Shannon H , LeBrasseur, Nathan K. , Lombard, David B. , Alberts, Susan C. , Campos, Fernando A. , Palavicini, Juan Pablo , Palmer, Allyson K. , Basisty, Nathan , Cabo, Rafael de , Baur, Joseph A. , Li, Xiaoling , Pletcher, Scott D. , Andersen, Julie Kay , Jones, Leanne, Suh, Yousin , Murray, Anna , Wang, Meng C., Henne, W. Mike , Walker, Keenan A. , Reiter, David A. , Gorbunova, Vera , Gladyshev, Vadim N. , Hurley, Jennifer , Esser, Karyn A. , Ashiqueali, Sarah , Reynolds, Lindsay M. , Zhang, Bohan , Sebastiani, Paola , Monti, Stefano , Schork, Nicholas J. , Rappaport, Noa

Mayo Clinic

The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences | February 11, 2025 | Volume: 80 | Issue: 5 | Pages: No page available

10.1093/gerona/glaf026 | PMID 39932386 Get It

Abstract The aging process is universal, and it is characterized by a progressive deterioration and decrease in physiological function leading to decline on the organismal level. Nevertheless, a number of genetic and nongenetic interventions have been described, which successfully extend healthspan and lifespan in different species. Furthermore, a number of clinical trials have been evaluating the feasibility of different interventions to promote human health. The goal of the annual Biological Sciences Section of the Gerontological Society of America meeting was to share current knowledge of different topics in aging research and provide a vision of the future of aging research. The meeting gathered international experts in diverse areas of aging research including basic biology, demography, and clinical and translational studies. Specific topics included metabolism, inflammaging, epigenetic clocks, frailty, senescence, neuroscience, stem cells, reproductive aging, inter-organelle crosstalk, comparative transcriptomics of longevity, circadian clock, metabolomics, and biodemography.
Characterization of Human Senescent Cell Biomarkers for Clinical Trials
Monroe, David G. , Atkinson, Elizabeth J. , Froemming, Mitchell N. , Ruan, Ming, LeBrasseur, Nathan K. , Khosla, Sundeep , Monroe, David G , LeBrasseur, Nathan K , Khosla, Sundeep , Farr, Joshua N.

Mayo Clinic

Aging Cell | January 17, 2025 | Volume: 24 | Issue: 5 | Pages: No page available

10.1111/acel.14489 | PMID 39823170 Get It

ABSTRACT There is an increasing need for biomarkers of senescent cell burden to facilitate the selection of participants for clinical trials. p16 Ink4a is encoded by the CDKN2A locus, which produces five variant transcripts in humans, two of which encode homologous p16 proteins: p16 Inka4a , encoded by p16_variant 1 , and p16ɣ, encoded by p16_variant 5. While distinct quantitative polymerase chain reaction primers can be designed for p16_variant 5, primers for p16_variant 1 also measure p16_variant 5 ( p16_variant 1 + 5 ). In a recent clinical trial evaluating the effects of the senolytic combination, dasatinib + quercetin (D + Q), on bone metabolism in postmenopausal women, we found that women in the highest tertile for T‐cell expression of p16_variant 5 had the most robust skeletal responses to D + Q. Importantly, the assessment of p16_variant 5 was more predictive of these responses than p16_variant 1 + 5 . Here, we demonstrate that in vitro, p16_variant 1 + 5 increased rapidly (Week 1) following the induction of DNA damage, whereas p16_variant 5 increased later (Week 4), suggesting that p16_variant 5 becomes detectable only when the abundance of senescent cells reaches some threshold. Further analysis identified a SASP panel in plasma that performed as well in identifying postmenopausal women with a positive skeletal response to D + Q. Collectively, our findings provide further support for the T‐cell p16_variant 5 assay as a biomarker for selecting participants in clinical trials of senolytic interventions. In addition, our data indicate that correlated plasma SASP markers could be used in lieu of the more technically challenging T‐cell p16 assay. Trial Registration: ClinicalTrials.gov identifier: NCT04313634.
THE SENESCENCE-ASSOCIATED SECRETOME AS A BIOMARKER OF AGING
LeBrasseur, Nathan K.

Mayo Clinic

Innovation in Aging | January 1, 2025 | Volume: 8 | Issue: Supplement_1 | Pages: 302-302

10.1093/geroni/igae098.0985 Get It

Abstract Senescent cells accumulate in nearly all organs with advancing age. A defining characteristic of senescent cells is a robust and heterogenous senescence-associated secretory phenotype (SASP). The SASP influences tissue health and function locally and systemically, hence, circulating components of the SASP may be informative of senescent cell burden. We established a candidate panel of senescence biomarkers based on common cytokines, chemokines, matrix remodeling proteins, growth factors and other proteins components of the SASP. In this seminar, the associations between senescence biomarkers and clinical manifestations of biological age, including frailty, functional limitations, and chronic disease, in humans will be presented. Moreover, the responsiveness of senescence biomarkers to interventions that counter the biology of aging, including exercise and caloric restriction, will be highlighted. Finally, the strengths and limitations of this approach and new directions will be discussed.
Premenopausal bilateral oophorectomy and Alzheimer's disease imaging biomarkers later in life
Kantarci, Kejal, Kapoor, Ekta , Geske, Jennifer R. , Fields, Julie A. , Knyazhanskaya, Evdokiya , Schwarz, Christopher G., Bailey, Kent R. , Lowe, Val J. , Rocca, Walter A. , Kantarci, Kejal , Castillo, Anna , Knyazhanskaya, Evdokiya E, Kantarci, Kejal , Geske, Jennifer , Kapoor, Ekta , Kara, Firat , Schwarz, Christopher G. , Senjem, Matthew L. , LeBrasseur, Nathan K. , Mielke, Michelle M.

Mayo Clinic

Alzheimer's & Dementia | December 23, 2024 | Volume: 21 | Issue: 7 | Pages: No page available

10.1002/alz.14469 | PMID 39711285 Get It

Abstract INTRODUCTION Premenopausal bilateral oophorectomy (PBO) before the age of 46 years is associated with an increased risk of dementia. We investigated the long‐term effects of PBO performed before age 50 years on amyloid beta (Aβ), tau, and neurodegeneration imaging biomarkers of Alzheimer's disease (AD). METHODS Mayo Clinic Cohort Study of Oophorectomy and Aging‐2 participants were divided into early PBO (< 46 years; n = 61), and late PBO (46–49 years; n = 51) groups and were compared to referent women who did not undergo PBO ( n = 119). RESULTS Early PBO was associated with thinner entorhinal cortex ( p = 0.014), higher tau load at higher levels of Aβ load ( Pp = 0.005), higher Aβ load ( p = 0.026), and smaller temporal lobe cortical thickness ( p = 0.022), only at older ages compared to the referent group. DISCUSSION PBO before the age of 46 years is associated with entorhinal cortex thinning, elevated tau at higher Aβ levels, along with an AD‐like pattern of atrophy at older ages. CLINICAL TRIALS REGISTRATION NCT03821857 sex‐specific effects of endocrine disruption on aging and AD. Highlights Premenopausal bilateral oophorectomy (PBO) before the ages of 46 (early PBO) years and ages 46 to 49 (late PBO) years was studied. Early PBO was associated with reduced entorhinal cortex thickness later in life. Early PBO was associated with greater amyloid beta (Aβ) load at older ages. Early PBO was associated with greater Alzheimer's disease pattern of atrophy at older ages. Early PBO was associated with higher tau load at higher Aβ levels.
Senescence Biomarkers and Trajectories of Frailty and Physical Function After Kidney Transplantation
Lorenz, Elizabeth C. , Smith, Byron H. , Wadei, Hani M. , Mour, Girish , Kennedy, Cassie C. , Schinstock, Carrie A. , Kremers, Walter K. , Cheville, Andrea , Hickson, LaTonya J. , Atkinson, Elizabeth J. , White, Thomas A. , Cheville, Andrea L , Rule, Andrew D , LeBrasseur, Nathan K , Smith, Byron , Hickson, LaTonya J , Schinstock, Carrie , Kennedy, Cassie C , Wadei, Hani M , Kremers, Walter K , Mour, Girish K , Rule, Andrew D. , LeBrasseur, Nathan K.

Mayo Clinic

Clinical Transplantation | November 20, 2024 | Volume: 38 | Issue: 11 | Pages: No page available

10.1111/ctr.70022 | PMID 39564682 Get It

ABSTRACTCellular senescence is a biological mechanism of aging and age‐related diseases. The aim of this study was to examine whether senescence biomarkers are associated with frailty and physical function trajectories in patients undergoing kidney transplantation (KT). We also discussed the relationship between senescence biomarkers and KT function. In this multicenter study, we prospectively assessed plasma levels of senescence biomarkers, frailty as measured by the Physical Frailty Phenotype, and physical function as measured by the Short Physical Performance Battery prior to KT. Frailty, physical function, and KT function were also measured 1 year after KT. Variable associations were assessed using Cox and relaxed least absolute shrinkage and selection operation regression. The cohort consisted of 197 participants (mean age 53 ± 13 years, 61.4% male, and 80.2% White race). Higher pre‐KT levels of macrophage‐derived chemokine (MDC/CCL22) and growth differentiation factor‐15 (GDF‐15) were independently associated with less improvement in frailty and/or physical function during the first year after KT. Higher pre‐KT levels tumor necrosis factor receptor superfamily member 6 (FAS) and MMP‐9 levels were independently associated with lower KT function one year after KT. Pre‐KT cellular senescence may contribute to frailty, physical function, and kidney function trajectories during the first year after KT.
The Fourth Annual Symposium of the Midwest Aging Consortium
Kim, Jinoh , Buffenstein, Rochelle , Vanegas, Natalia-Del Pilar , Agudelo-Garcia, Paula A., Rojas, Mauricio , Englund, Davis A. , Nunes, Allancer , Kohut, Marian L. , Kothadiya, Siddhant , Bardhan, Rizia , Camell, Christina D. , Sturmlechner, Ines , Lamming, Dudley W. , Leiser, Scott F. , Escorcia, Wilber , Gill, Matthew S. , Helfand, Stephen L., Korm, Sovannarith , Pehar, Mariana , Blaszkiewicz, Magdalena , McGregor, Eric R. , Stilgenbauer, Lukas , Taylor, Alicia , McNeill, Elizabeth M. , Sturmlechner, Ines , Lamming, Dudley W , Anderson, Rozalyn M , Bai, Hua , Englund, Davis A. , Bronikowski, Anne M. , Rosas, Lorena , Mora, Ana Lucia , LeBrasseur, Nathan K. , Robbins, Paul D. , Goronzy, Jörg J. , Yeh, Chung‐Yang , Huang, Shijiao , Taylor, Jackson R. , Gribble, Kristin E. , Townsend, Kristy L. , Anderson, Rozalyn M. , Sadagurski, Marianna , Stoeger, Thomas

Mayo Clinic

The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences | November 5, 2024 | Volume: 79 | Issue: 11 | Pages: No page available

10.1093/gerona/glae236 | PMID 39498863 Get It

Abstract The Midwest Aging Consortium (MAC) has emerged as a critical collaborative initiative aimed at advancing our understanding of aging and developing strategies to combat the rising prevalence of age-related diseases. Founded in 2019, MAC brings together researchers from various disciplines and institutions across the Midwestern United States to foster interdisciplinary geroscience research. This report summarizes the highlights of the Fourth Annual Symposium of MAC, which was held at Iowa State University in May 2023. The symposium featured presentations on a wide array of topics, including studies on slow-aging animals, cellular senescence and senotherapeutics, the role of the immune system in aging, metabolic changes in aging, neuronal health in aging, and biomarkers for measuring the aging process. Speakers shared findings from studies involving a variety of animals, ranging from commonly used species such as mice, rats, worms, yeast, and fruit flies, to less-common ones like naked mole-rats, painted turtles, and rotifers. MAC continues to emphasize the importance of supporting emerging researchers and fostering a collaborative environment, positioning itself as a leader in aging research. This symposium not only showcased the current state of aging biology research but also highlighted the consortium’s role in training the next generation of scientists dedicated to improving the healthspan and well-being of the aging population.