scholarly journals MECHANISMS OF BRAIN REJUVENATION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S587-S587
Author(s):  
Saul Villeda

Abstract A growing body of work has shown that systemic manipulations, such as heterochronic parabiosis and young blood administration, can partially reverse age-related cellular impairments and loss of cognitive faculties in the aged brain. These studies have revealed an age-dependent bi-directionality in the influence of the systemic environment indicating anti-aging factors in young blood elicit rejuvenation while pro-aging factors in old blood drive aging. It has been proposed that introducing anti-aging factors or mitigating the effect of pro-aging factors may provide effective strategies to rejuvenate aging phenotypes. Despite this potential, much is unknown as to the systemic and molecular mechanisms regulating anti-aging and pro-aging effects of blood-borne factors. I will discuss work from my research group that begins to provide mechanistic insight into the systemic and molecular drivers promoting rejuvenation in the aging brain.

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 198-198
Author(s):  
Saul Villeda

Abstract Aging drives cellular and cognitive impairments in the adult brain. It is imperative to gain mechanistic insight into what drives aging phenotypes in the brain in order to maintain, and even restore, functional integrity in the elderly. We, and others, have shown that systemic manipulations - such as heterochronic parabiosis (in which a young and old circulatory system are joined) and administration of young blood or exercise induced blood factors - can reverse age-related impairments in regenerative, synaptic and inflammatory processes, as well as rescue cognitive faculties in the aged brain. These studies have revealed an age-dependent bi-directionality in the influence of the systemic environment indicating pro-youthful factors in young blood elicit rejuvenation while pro-aging factors in old blood drive aging. It has been proposed that introducing pro-youthful factors or mitigating the effect of pro-aging factors may provide effective strategies to rejuvenate aging phenotypes in the brain. Despite this potential, much is unknown as to the systemic and molecular mechanisms regulating pro-youthful and pro-aging effects of blood-borne factors. I will discuss work from my research group that begins to provide mechanistic insight into the systemic and molecular drivers promoting rejuvenation in the aging brain.


2020 ◽  
Vol 319 (1) ◽  
pp. C45-C63
Author(s):  
Jeffrey S. Isenberg ◽  
David D. Roberts

Numerous age-dependent alterations at the molecular, cellular, tissue and organ systems levels underlie the pathophysiology of aging. Herein, the focus is upon the secreted protein thrombospondin-1 (TSP1) as a promoter of aging and age-related diseases. TSP1 has several physiological functions in youth, including promoting neural synapse formation, mediating responses to ischemic and genotoxic stress, minimizing hemorrhage, limiting angiogenesis, and supporting wound healing. These acute functions of TSP1 generally require only transient expression of the protein. However, accumulating basic and clinical data reinforce the view that chronic diseases of aging are associated with accumulation of TSP1 in the extracellular matrix, which is a significant maladaptive contributor to the aging process. Identification of the relevant cell types that chronically produce and respond to TSP1 and the molecular mechanisms that mediate the resulting maladaptive responses could direct the development of therapeutic agents to delay or revert age-associated maladies.


2010 ◽  
Vol 205 (3) ◽  
pp. 201-210 ◽  
Author(s):  
Sebastio Perrini ◽  
Luigi Laviola ◽  
Marcos C Carreira ◽  
Angelo Cignarelli ◽  
Annalisa Natalicchio ◽  
...  

The widespread increase in life expectancy is accompanied by an increased prevalence of features of physical frailty. Signs and symptoms may include sarcopenia and osteopenia, reduced exercise capacity, and diminished sense of well-being. The pathogenesis of age-associated sarcopenia and osteopenia is multifactorial, and hormonal decline may be a contributing factor. Aging is associated with a progressive decrease in GH secretion, and more than 30% of elderly people have circulating IGF1 levels below the normal range found in the young. GH acts directly on target tissues, including skeletal muscle and bone among many others, but many effects are mediated indirectly by circulating (liver-derived) or locally produced IGF1. Aging is also associated with reduced insulin sensitivity which, in turn, may contribute to the impairment of IGF1 action. Recent experimental evidence suggests that besides the age-dependent decline in GH and IGF1 serum levels, the dysregulation of GH and IGF1 actions due to impairment of the post-receptor signaling machinery may contribute to the loss of muscle mass and osteopenia. This article will focus on the molecular mechanisms of impaired GH and IGF1 signaling and action in aging, and their role in the pathogenesis of sarcopenia and osteoporosis.


Author(s):  
Bing Si Li ◽  
Ri Zhe Zhu ◽  
Seok-Hee Lim ◽  
Jae Ho Seo ◽  
Byung-Min Choi

Oxidative stress-induced cellular senescence is now regarded as an important driving mechanism in chronic lung diseases-particularly chronic obstructive pulmonary disease (COPD). 4′,5,7-trihydroxyflavone (Apigenin) is a natural flavonoid product abundantly present in fruits, vegetables, and Chinese medicinal herbs. It has been known that apigenin has anti-oxidant, anti-inflammatory and liver-protecting effects. The efficacy of apigenin for lung aging, however, has not been reported. In this study, we selected the hydrogen peroxide (H2O[Formula: see text]- or doxorubicin (DOXO)-induced senescence model in WI-38 human embryonic lung fibroblast cells to determine the potential anti-aging effects of apigenin in vitro and associated molecular mechanisms. We found that apigenin reduced senescence-associated [Formula: see text]-galactosidase (SA-[Formula: see text]-gal) activity and promoted cell growth, concomitant with a decrease in levels of Acetyl (ac)-p53, p21[Formula: see text], and p16[Formula: see text] and an increase in phospho (p)-Rb. Apigenin also increased the activation ratio of silent information regulator 1 (SIRT1), nicotinamide adenine dinucleotide (NAD[Formula: see text], and NAD[Formula: see text]/NADH and inhibited cluster of differentiation 38 (CD38) activity in a concentration-dependent manner. SIRT1 inhibition by SIRT1 siRNA abolished the anti-aging effect of apigenin. In addition, CD38 inhibition by CD38 siRNA or apigenin increased the SIRT1 level and reduced H2O2-induced senescence. Our findings suggest that apigenin is a promising phytochemical for reducing the impact of senescent cells in age-related lung diseases such as COPD.


2018 ◽  
Vol 119 (2) ◽  
pp. 509-520 ◽  
Author(s):  
Faisal Karmali ◽  
Gregory T. Whitman ◽  
Richard F. Lewis

The brain uses information from different sensory systems to guide motor behavior, and aging is associated with simultaneous decline in the quality of sensory information provided to the brain and deterioration in motor control. Correlations between age-dependent decline in sensory anatomical structures and behavior have been demonstrated in many sensorimotor systems, and it has recently been suggested that a Bayesian framework could explain these relationships. Here we show that age-dependent changes in a human sensorimotor reflex, the vestibuloocular reflex, are explained by a Bayesian optimal adaptation in the brain occurring in response to death of motion-sensing hair cells. Specifically, we found that the temporal dynamics of the reflex as a function of age emerge from ( r = 0.93, P < 0.001) a Kalman filter model that determines the optimal behavioral output when the sensory signal-to-noise characteristics are degraded by death of the transducers. These findings demonstrate that the aging brain is capable of generating the ideal and statistically optimal behavioral response when provided with deteriorating sensory information. While the Bayesian framework has been shown to be a general neural principle for multimodal sensory integration and dynamic sensory estimation, these findings provide evidence of longitudinal Bayesian processing over the human life span. These results illuminate how the aging brain strives to optimize motor behavior when faced with deterioration in the peripheral and central nervous systems and have implications in the field of vestibular and balance disorders, as they will likely provide guidance for physical therapy and for prosthetic aids that aim to reduce falls in the elderly.NEW & NOTEWORTHY We showed that age-dependent changes in the vestibuloocular reflex are explained by a Bayesian optimal adaptation in the brain that occurs in response to age-dependent sensory anatomical changes. This demonstrates that the brain can longitudinally respond to age-related sensory loss in an ideal and statistically optimal way. This has implications for understanding and treating vestibular disorders caused by aging and provides insight into the structure-function relationship during aging.


2021 ◽  
Vol 22 (6) ◽  
pp. 3107
Author(s):  
Noemi Sola-Sevilla ◽  
Ana Ricobaraza ◽  
Ruben Hernandez-Alcoceba ◽  
Maria S. Aymerich ◽  
Rosa M. Tordera ◽  
...  

Sirtuin 2 (SIRT2) has been associated to aging and age-related pathologies. Specifically, an age-dependent accumulation of isoform 3 of SIRT2 in the CNS has been demonstrated; however, no study has addressed the behavioral or molecular consequences that this could have on aging. In the present study, we have designed an adeno-associated virus vector (AAV-CAG-Sirt2.3-eGFP) for the overexpression of SIRT2.3 in the hippocampus of 2 month-old SAMR1 and SAMP8 mice. Our results show that the specific overexpression of this isoform does not induce significant behavioral or molecular effects at short or long term in the control strain. Only a tendency towards a worsening in the performance in acquisition phase of the Morris Water Maze was found in SAMP8 mice, together with a significant increase in the pro-inflammatory cytokine Il-1β. These results suggest that the age-related increase of SIRT2.3 found in the brain is not responsible for induction or prevention of senescence. Nevertheless, in combination with other risk factors, it could contribute to the progression of age-related processes. Understanding the specific role of SIRT2 on aging and the underlying molecular mechanisms is essential to design new and more successful therapies for the treatment of age-related diseases.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Luis Fernando Hernandez-Zimbron ◽  
Rosario Gulias-Cañizo ◽  
María F. Golzarri ◽  
Blanca Elizabeth Martínez-Báez ◽  
Hugo Quiroz-Mercado ◽  
...  

Purpose. To examine the current knowledge about the age-related processes in the anterior segment of the eye at a biological, clinical, and molecular level. Methods. We reviewed the available published literature that addresses the aging process of the anterior segment of the eye and its associated molecular and physiological events. We performed a search on PubMed, CINAHL, and Embase using the MeSH terms “eye,” “anterior segment,” and “age.” We generated searches to account for synonyms of these keywords and MESH headings as follows: (1) “Eye” AND “ageing process” OR “anterior segment ageing” and (2) “Anterior segment” AND “ageing process” OR “anterior segment” AND “molecular changes” AND “age.” Results. Among the principal causes of age-dependent alterations in the anterior segment of the eye, we found the mutation of the TGF-β gene and loss of autophagy in addition to oxidative stress, which contributes to the pathogenesis of degenerative diseases. Conclusions. In this review, we summarize the current knowledge regarding some of the molecular mechanisms related to aging in the anterior segment of the eye. We also introduce and propose potential roles of autophagy, an important mechanism responsible for maintaining homeostasis and proteostasis under stress conditions in the anterior segment during aging.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
S. Falone ◽  
S. Jr Santini ◽  
V. Cordone ◽  
M. Grannonico ◽  
M. Cacchio ◽  
...  

Population aging results in urgent needs of interventions aimed at ensuring healthy senescence. Exercise often results in healthy aging, yet many molecular mechanisms underlying such effects still need to be identified. We here investigated whether the age-dependent accumulation of oxidative and methylglyoxal- (MG-) related molecular damage could be delayed by moderate exercise in the mouse ovary, an organ that first exhibits impaired function with advancing age in mammals. CD1 female mice underwent two- or four-month treadmill-based running through the transition from adult to middle age, when ovaries show signs of senescence, and markers of protection against reactive oxygen species (ROS) and MG were measured. The long-term exercise reduced the protein oxidative damage in the ovaries (P<0.01), and this was linked to the preservation of the glutathione peroxidase protection against ROS (P<0.001), as well as to the increased glutathione availability (P<0.001). Conversely, even though the age-related deactivation of the MG-targeting systems was partially prevented by the long-term running programme (P<0.001), exercised mice were not protected from the age-dependent glycative burden. In summary, lately initiated regular and moderate exercise limited some changes occurring in the ovaries of middle-aged mice, and this might help to develop nonpharmacological cointerventions to reduce the vulnerability of mammalian ovaries towards redox dysfunctions.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2013
Author(s):  
Błażej Westfalewicz ◽  
Mariola Słowińska ◽  
Sylwia Judycka ◽  
Andrzej Ciereszko ◽  
Mariola A. Dietrich

The age of the bull is widely accepted to influence the production of sperm, affecting the amount and quality of produced semen, which in turn impacts the results of cryopreservation. However, the exact influence of the maturation process on cryopreserved sperm, as well as the underlying molecular mechanisms of this process, are not fully understood. The goal of this study was to evaluate changes in the proteome of thawed semen (spermatozoa and supernatant) collected from young and adult bulls (n = 6) using the 2D-DIGE approach. The quality of semen was assessed using a CASA system and flow cytometry. We found no significant age-related variation in semen quality, with the exception of the average path velocity of sperm movement, which was higher in adult bulls. Proteomic analysis indicated 15 spermatozoa proteins and 10 supernatant proteins with significant age-related changes. Our results suggest that semen from adult bulls is better equipped with proteins related to energy production, protection of spermatozoa against oxidative stress and fertilizing ability. Proteins increased in abundance in young bull spermatozoa were connected to the cytoskeleton and its development, which strongly suggests that developmental processes are still in progress. In conclusion, our results provide novel insight into the mechanism of the development of the male reproductive system of cattle.


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