Longevity, cellular senescence and the gut microbiome: Lessons to be learned from crocodiles

Gut Microbiome and Cellular Senescence in the Context of Aging and Disease: An Emerging Frontier

10.20944/preprints202105.0372.v1 ◽

2021 ◽

Author(s):

Rohit Sharma

Keyword(s):

Gut Microbiota ◽

Cellular Senescence ◽

Gut Microbiome ◽

Biological Aging ◽

Future Research ◽

Age Related ◽

Integrative View ◽

Health And Disease ◽

Molecular Aspects ◽

Relationship Of

The significance of diversity, composition, and functional attributes of the gut microbiota is recognized in human health and disease. Studies have also shown that the gut microbiota is related to human aging, and a causal relationship between gut microflora dysbiosis and chronic age-related disorders is also becoming apparent. Further, emerging evidence indicates that age-associated changes in the gut microbiome are predictors of human survival and longevity. Recent advances in our understanding of the cellular and molecular aspects of biological aging have revealed a cellular senescence-centric view of the aging process. However, the association between gut microbiome and cellular senescence is only beginning to be understood. The present review provides an integrative view of the emerging relationship between the gut microbiome and cellular senescence in aging and disease. Evidence relating to microbiome-mediated modulation of senescent cells, as well as senescent cells-mediated changes in intestinal homeostasis have been discussed. Unanswered questions and future research directions have also been deliberated to truly ascertain the relationship of the gut microbiome and cellular senescence for developing microbiome-based age-delaying and longevity promoting therapies.

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Emerging Interrelationship Between the Gut Microbiome and Cellular Senescence in the Context of Aging and Disease: Perspectives and Therapeutic Opportunities

Probiotics and Antimicrobial Proteins ◽

10.1007/s12602-021-09903-3 ◽

2022 ◽

Author(s):

Rohit Sharma

Keyword(s):

Cellular Senescence ◽

Gut Microbiome

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Lamin B receptor: role on chromatin structure, cellular senescence and possibly aging

Biochemical Journal ◽

10.1042/bcj20200165 ◽

2020 ◽

Vol 477 (14) ◽

pp. 2715-2720

Author(s):

Susana Castro-Obregón

Keyword(s):

Cellular Senescence ◽

Nuclear Membrane ◽

Chromatin Structure ◽

Cholesterol Synthesis ◽

Reductase Activity ◽

Chimeric Protein ◽

Nuclear Lamina ◽

Lamin B ◽

Inner Nuclear Membrane ◽

Lamin B Receptor

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.

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Folate and vitamin B-12 deficiencies additively impaired memory function and disturbed the gut microbiota in amyloid-β infused rats

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000624 ◽

2019 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Sunmin Park ◽

Sunna Kang ◽

Da Sol Kim

Keyword(s):

Insulin Resistance ◽

Gut Microbiota ◽

Insulin Signaling ◽

Gut Microbiome ◽

Metabolic Diseases ◽

Memory Function ◽

Amyloid Β ◽

Impaired Memory ◽

Ca1 Region ◽

Folate And Vitamin B12

Abstract. Folate and vitamin B12(V-B12) deficiencies are associated with metabolic diseases that may impair memory function. We hypothesized that folate and V-B12 may differently alter mild cognitive impairment, glucose metabolism, and inflammation by modulating the gut microbiome in rats with Alzheimer’s disease (AD)-like dementia. The hypothesis was examined in hippocampal amyloid-β infused rats, and its mechanism was explored. Rats that received an amyloid-β(25–35) infusion into the CA1 region of the hippocampus were fed either control(2.5 mg folate plus 25 μg V-B12/kg diet; AD-CON, n = 10), no folate(0 folate plus 25 μg V-B12/kg diet; AD-FA, n = 10), no V-B12(2.5 mg folate plus 0 μg V-B12/kg diet; AD-V-B12, n = 10), or no folate plus no V-B12(0 mg folate plus 0 μg V-B12/kg diet; AD-FAB12, n = 10) in high-fat diets for 8 weeks. AD-FA and AD-VB12 exacerbated bone mineral loss in the lumbar spine and femur whereas AD-FA lowered lean body mass in the hip compared to AD-CON(P < 0.05). Only AD-FAB12 exacerbated memory impairment by 1.3 and 1.4 folds, respectively, as measured by passive avoidance and water maze tests, compared to AD-CON(P < 0.01). Hippocampal insulin signaling and neuroinflammation were attenuated in AD-CON compared to Non-AD-CON. AD-FAB12 impaired the signaling (pAkt→pGSK-3β) and serum TNF-α and IL-1β levels the most among all groups. AD-CON decreased glucose tolerance by increasing insulin resistance compared to Non-AD-CON. AD-VB12 and AD-FAB12 increased insulin resistance by 1.2 and 1.3 folds, respectively, compared to the AD-CON. AD-CON and Non-AD-CON had a separate communities of gut microbiota. The relative counts of Bacteroidia were lower and those of Clostridia were higher in AD-CON than Non-AD-CON. AD-FA, but not V-B12, separated the gut microbiome community compared to AD-CON and AD-VB12(P = 0.009). In conclusion, folate and B-12 deficiencies impaired memory function by impairing hippocampal insulin signaling and gut microbiota in AD rats.

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