scholarly journals Mitochondria and Calcium Homeostasis: Cisd2 as a Big Player in Cardiac Ageing

2020 ◽  
Vol 21 (23) ◽  
pp. 9238
Author(s):  
Chi-Hsiao Yeh ◽  
Yi-Ju Chou ◽  
Cheng-Heng Kao ◽  
Ting-Fen Tsai

The ageing of human populations has become a problem throughout the world. In this context, increasing the healthy lifespan of individuals has become an important target for medical research and governments. Cardiac disease remains the leading cause of morbidity and mortality in ageing populations and results in significant increases in healthcare costs. Although clinical and basic research have revealed many novel insights into the pathways that drive heart failure, the molecular mechanisms underlying cardiac ageing and age-related cardiac dysfunction are still not fully understood. In this review we summarize the most updated publications and discuss the central components that drive cardiac ageing. The following characters of mitochondria-related dysfunction have been identified during cardiac ageing: (a) disruption of the integrity of mitochondria-associated membrane (MAM) contact sites; (b) dysregulation of energy metabolism and dynamic flexibility; (c) dyshomeostasis of Ca2+ control; (d) disturbance to mitochondria–lysosomal crosstalk. Furthermore, Cisd2, a pro-longevity gene, is known to be mainly located in the endoplasmic reticulum (ER), mitochondria, and MAM. The expression level of Cisd2 decreases during cardiac ageing. Remarkably, a high level of Cisd2 delays cardiac ageing and ameliorates age-related cardiac dysfunction; this occurs by maintaining correct regulation of energy metabolism and allowing dynamic control of metabolic flexibility. Together, our previous studies and new evidence provided here highlight Cisd2 as a novel target for developing therapies to promote healthy ageing

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Makoto Kuro-o

The basic research of aging has been primarily focused on elucidating mechanisms of aging and longevity that are evolutionarily conserved from yeasts to primates. Such efforts have culminated in the notion that (1) senescence at the cellular level is associated with aging at the organismal level and that (2) calorie restriction and growth suppression decelerate aging. However, these important findings in the basic research have not necessarily been linked to improvement of daily medical practice in the aging society. It has become increasingly important to investigate mechanisms of aging unique to mammals or humans and apply the research fruits for the treatment of major age-related disorders to extend the health span. Seminal studies on the klotho mouse, a mutant exhibiting a premature aging syndrome, have identified phosphate as a proaging factor in mammals. In this review, mechanisms of phosphate-induced premature aging and potential therapeutic targets will be discussed, which may be directly applicable for developing novel strategies for the treatment of chronic kidney disease and its complications.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Urata ◽  
K Ikeda ◽  
T Nakagawa ◽  
A Hoshino ◽  
S Honda ◽  
...  

Abstract Background Ischemic disease is prevalent in elderly population due to impaired angiogenesis. Endothelial cell (EC) generates energy largely via glycolysis, which is further activated when angiogenesis actively occurs. PFK-1 is one of the most important regulatory enzymes for glycolysis, which is activated by PFKFB3. On the other hand, TIGAR inhibits PFK-1 under the control of p53. Crucial roles of PFKFB3 in EC functions under physiological and pathological conditions have been reported; however, a role of TIGAR in EC angiogenic functions remains to be elucidated. Furthermore, it remains unknown whether and how cellular senescence affect the energy metabolism in EC. Purpose The purpose of this study is to investigate molecular mechanisms underlying EC dysfunction associated with ageing, especially by focusing on endothelial energy metabolism. Method and result Senescent EC showed reduced glucose consumption assessed by [U-13C]-glucose tracer assay in association with increased expression of p53 and TIGAR. Angiogenic capacity assessed by tube-formation assay was reduced in senescent EC. Of note, either silencing of TIGAR by siRNA or lentivirus-mediated overexpression of PFKFB3 improved angiogenic capacity in senescent EC. These results collectively suggest that senescence impairs glycolysis in EC by activating p53-TIGAR axis, which leads to senescence-associated endothelial dysfunction. To analyze an impact of EC senescence in angiogenesis in vivo, we generated EC-specific progeroid mice in which dominant negative form of telomere repeat-binding factor 2 (TRF2) was overexpressed in EC under the control of the TIE2 promoter. After confirming EC-specific senescence in these endothelial progeroid mice, we generated hind-limb ischemia model. Recovery of blood flow assessed by laser doppler velocimeter was significantly impaired in endothelial progeroid mice, indicating that EC senescence is directly and causally implicated in age-related angiogenic dysfunction. Of note, genetic inactivation of TIGAR completely rescued the impaired ischemia-induced neovessel formation in EC-specific progeroid mice. Conclusion Using unique endothelial progeroid mice, we revealed that EC senescence is a bona fide risk for ischemic disease, largely by reducing glycolysis in EC through p53-TIGAR axis. Our data suggest that endothelial energy metabolism is an attracting therapeutic target for the prevention and/or treatment of ischemic diseases, especially in elderly population.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mingjing Yan ◽  
Shenghui Sun ◽  
Kun Xu ◽  
Xiuqing Huang ◽  
Lin Dou ◽  
...  

With research progress on longevity, we have gradually recognized that cardiac aging causes changes in heart structure and function, including progressive myocardial remodeling, left ventricular hypertrophy, and decreases in systolic and diastolic function. Elucidating the regulatory mechanisms of cardiac aging is a great challenge for biologists and physicians worldwide. In this review, we discuss several key molecular mechanisms of cardiac aging and possible prevention and treatment methods developed in recent years. Insights into the process and mechanism of cardiac aging are necessary to protect against age-related diseases, extend lifespan, and reduce the increasing burden of cardiovascular disease in elderly individuals. We believe that research on cardiac aging is entering a new era of unique significance for the progress of clinical medicine and social welfare.


Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.


2019 ◽  
Vol 25 (29) ◽  
pp. 3098-3111 ◽  
Author(s):  
Luca Liberale ◽  
Giovanni G. Camici

Background: The ongoing demographical shift is leading to an unprecedented aging of the population. As a consequence, the prevalence of age-related diseases, such as atherosclerosis and its thrombotic complications is set to increase in the near future. Endothelial dysfunction and vascular stiffening characterize arterial aging and set the stage for the development of cardiovascular diseases. Atherosclerotic plaques evolve over time, the extent to which these changes might affect their stability and predispose to sudden complications remains to be determined. Recent advances in imaging technology will allow for longitudinal prospective studies following the progression of plaque burden aimed at better characterizing changes over time associated with plaque stability or rupture. Oxidative stress and inflammation, firmly established driving forces of age-related CV dysfunction, also play an important role in atherosclerotic plaque destabilization and rupture. Several genes involved in lifespan determination are known regulator of redox cellular balance and pre-clinical evidence underlines their pathophysiological roles in age-related cardiovascular dysfunction and atherosclerosis. Objective: The aim of this narrative review is to examine the impact of aging on arterial function and atherosclerotic plaque development. Furthermore, we report how molecular mechanisms of vascular aging might regulate age-related plaque modifications and how this may help to identify novel therapeutic targets to attenuate the increased risk of CV disease in elderly people.


2019 ◽  
Vol 19 (10) ◽  
pp. 705-718 ◽  
Author(s):  
Naima Mansoor ◽  
Fazli Wahid ◽  
Maleeha Azam ◽  
Khadim Shah ◽  
Anneke I. den Hollander ◽  
...  

: Age-related macular degeneration (AMD) is an eye disorder affecting predominantly the older people above the age of 50 years in which the macular region of the retina deteriorates, resulting in the loss of central vision. The key factors associated with the pathogenesis of AMD are age, smoking, dietary, and genetic risk factors. There are few associated and plausible genes involved in AMD pathogenesis. Common genetic variants (with a minor allele frequency of >5% in the population) near the complement genes explain 40–60% of the heritability of AMD. The complement system is a group of proteins that work together to destroy foreign invaders, trigger inflammation, and remove debris from cells and tissues. Genetic changes in and around several complement system genes, including the CFH, contribute to the formation of drusen and progression of AMD. Similarly, Matrix metalloproteinases (MMPs) that are normally involved in tissue remodeling also play a critical role in the pathogenesis of AMD. MMPs are involved in the degradation of cell debris and lipid deposits beneath retina but with age their functions get affected and result in the drusen formation, succeeding to macular degeneration. In this review, AMD pathology, existing knowledge about the normal and pathological role of complement system proteins and MMPs in the eye is reviewed. The scattered data of complement system proteins, MMPs, drusenogenesis, and lipofusogenesis have been gathered and discussed in detail. This might add new dimensions to the understanding of molecular mechanisms of AMD pathophysiology and might help in finding new therapeutic options for AMD.


2019 ◽  
Vol 19 (3) ◽  
pp. 259-273 ◽  
Author(s):  
Neelam Kaushal ◽  
Divya Vohora ◽  
Rajinder K Jalali ◽  
Sujeet Jha

Background And Objective:Osteoporosis is a common bone disorder that increases susceptibility to fragility bone fractures. The clinical and public health repercussions of osteoporosis are huge due to the morbidity, mortality, and cost of medical care linked with fragility fractures. Clinical assessment of osteoporotic risk factors can help to identify candidates at an early stage that will benefit from medical intervention and potentially lowering the morbidity and mortality seen with fractures and complications. Given this, research is ongoing to evaluate the association of osteoporosis with some novel or less well-studied risk factors/bio-markers such as uric acid (UA).Discussion:Uric acid’s antioxidant activity has been proposed to be one of the factors responsible for increasing longevity and lowering rates of age-related cancers during primate evolution, the level of which increased markedly due to loss of uricase enzyme activity (mutational silencing). Accumulated evidence shows that oxidative stress is the fundamental mechanism of age-related bone loss and acts via enhancing osteoclastic activity and increasing bone resorption. Antioxidant substances such as ascorbic acid scavenge free radicals are positively related to bone health. Thus, it is hypothesized that uric acid holds bone-protective potential owing to its potent antioxidative property. Several correlation studies have been conducted globally to investigate the relationship between serum uric acid with bone mineral density and osteoporosis. Few pre-clinical studies have tried to investigate the interaction between uric acid and bone mineral density and reported important role played via Runt-related transcription factor 2 (RUNX2)/core-binding factor subunit alpha-1 (CBF-alpha-1), Wingless-related integration site (Wnt)-3a/β-catenin signaling pathway and 11β Hydroxysteroid Dehydrogenase type 1.Conclusion:In this review, the authors provided a comprehensive summary of the literature related to association studies reported in humans as well work done until date to understand the potential cellular and molecular mechanisms that interplay between uric acid and bone metabolism.


Author(s):  
Jonathan E. Peelle

Language processing in older adulthood is a model of balance between preservation and decline. Despite widespread changes to physiological mechanisms supporting perception and cognition, older adults’ language abilities are frequently well preserved. At the same time, the neural systems engaged to achieve this high level of success change, and individual differences in neural organization appear to differentiate between more and less successful performers. This chapter reviews anatomical and cognitive changes that occur in aging and popular frameworks for age-related changes in brain function, followed by an examination of how these principles play out in the context of language comprehension and production.


2019 ◽  
Vol 104 (11) ◽  
pp. 5372-5381 ◽  
Author(s):  
Nigel K Stepto ◽  
Alba Moreno-Asso ◽  
Luke C McIlvenna ◽  
Kirsty A Walters ◽  
Raymond J Rodgers

Abstract Context Polycystic ovary syndrome (PCOS) is a common endocrine condition affecting 8% to 13% of women across the lifespan. PCOS affects reproductive, metabolic, and mental health, generating a considerable health burden. Advances in treatment of women with PCOS has been hampered by evolving diagnostic criteria and poor recognition by clinicians. This has resulted in limited clinical and basic research. In this study, we provide insights into the current and future research on the metabolic features of PCOS, specifically as they relate to PCOS-specific insulin resistance (IR), that may affect the most metabolically active tissue, skeletal muscle. Current Knowledge PCOS is a highly heritable condition, yet it is phenotypically heterogeneous in both reproductive and metabolic features. Human studies thus far have not identified molecular mechanisms of PCOS-specific IR in skeletal muscle. However, recent research has provided new insights that implicate energy-sensing pathways regulated via epigenomic and resultant transcriptomic changes. Animal models, while in existence, have been underused in exploring molecular mechanisms of IR in PCOS and specifically in skeletal muscle. Future Directions Based on the latest evidence synthesis and technologies, researchers exploring molecular mechanisms of IR in PCOS, specifically in muscle, will likely need to generate new hypothesis to be tested in human and animal studies. Conclusion Investigations to elucidate the molecular mechanisms driving IR in PCOS are in their early stages, yet remarkable advances have been made in skeletal muscle. Overall, investigations have thus far created more questions than answers, which provide new opportunities to study complex endocrine conditions.


Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 485
Author(s):  
Lorenzo Cuollo ◽  
Fabrizio Antonangeli ◽  
Angela Santoni ◽  
Alessandra Soriani

Cellular senescence represents a robust tumor-protecting mechanism that halts the proliferation of stressed or premalignant cells. However, this state of stable proliferative arrest is accompanied by the Senescence-Associated Secretory Phenotype (SASP), which entails the copious secretion of proinflammatory signals in the tissue microenvironment and contributes to age-related conditions, including, paradoxically, cancer. Novel therapeutic strategies aim at eliminating senescent cells with the use of senolytics or abolishing the SASP without killing the senescent cell with the use of the so-called “senomorphics”. In addition, recent works demonstrate the possibility of modifying the composition of the secretome by genetic or pharmacological intervention. The purpose is not to renounce the potent immunostimulatory nature of SASP, but rather learning to modulate it for combating cancer and other age-related diseases. This review describes the main molecular mechanisms regulating the SASP and reports the evidence of the feasibility of abrogating or modulating the SASP, discussing the possible implications of both strategies.


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