Mechanisms Of Cellular Senescence Research Articles

P1192 Deciphering the colonic immune landscape of UC from cellular senescence by integrated bioinformatics analysis and machine learning

Abstract Background Nowadays, there has been extensive interest in cellular senescence in gastrointestinal diseases. However, the pathological mechanism of cellular senescence in UC and its involvement in colonic immune characteristics remain enigmatic. Therefore, we aimed to investigate the contribution of cellular senescence-related signatures to the colonic immune landscape in UC based on bioinformatics combined machine learning strategy. Methods Three gene sets of UC were selected from the Gene Expression Omnibus database, including two training sets and one testing set. We identified cellular senescence-associated differentially expressed genes (DEGs) in UC and performed functional enrichment analysis. Afterwards, signature genes were determined by machine learning algorithms including least absolute shrinkage and selection operator (LASSO) regression, support vector machine recursive feature elimination (SVM-RFE), and artificial neural network (ANN). Furthermore, distinct immune microenvironment abnormalities in UC were comprehensively explored, and the correlation between the signature genes and the colonic immune landscape of UC was also evaluated. Based on the signature genes, we clustered UC samples into distinct subtypes by consensus clustering analysis. Finally, we performed validation of the signature genes in dextran sulfate sodium salt (DSS)-induced colitis. Results 41 cellular senescence-associated DEGs in UC were identified by intersecting DEGs with the cellular senescence-associated genes from the CellAge database, which were associated with cellular senescence and immune pathways. Following that, seven signature genes were determined by the machine learning method of LASSO regression, SVM-RFE, and ANN, comprising CXCL1, MMP9, CYR61, BAG3, PEX19, RPS6KA6, and ETS2, which were also validated in the testing set. Furthermore, we obtained the most correlated pairs of UC signature genes-immunocytes and found these signature genes were highly corelated with neutrophils and activated CD4+ memory T cells. Additionally, the expression profiling of human leukocyte antigen genes and immune checkpoints were also analyzed. Subsequently, two molecular subtypes related to senescence that exhibit significantly different immune characteristics were identified. Finally, the mRNA levels of the signature genes were confirmed in DSS-induced colitis, which were congruent with results gained from the datasets. Conclusion In summary, the result has emphasized the essential function of cellular senescence-associated genes in controlling the immune microenvironment for UC. The exploration of the etiopathogenesis of UC through cellular senescence is anticipated to lead to novel advancements in disease diagnosis and potential treatments.

Prognostic value and potential mechanism of cellular senescence and tumor microenvironment in hepatocellular carcinoma: Insights from bulk transcriptomics and single-cell sequencing analysis.

The high mortality rate and postoperative recurrence of hepatocellular carcinoma (HCC) contribute to the burden on society and healthcare. The prognostic value and underlying mechanisms of cellular senescence and tumor microenvironment (TME) in HCC remain unclear. Bulk transcriptomic data were obtained from 368 HCC samples in The Cancer Genome Atlas-liver hepatocellular carcinoma cohort and 64 samples from the GSE116174 dataset. Single-cell RNA sequencing (scRNA-seq) data of HCC were obtained from the GSE149614 dataset, including 18 tumor samples from 10 patients. Prognosis-related cellular senescence genes and immune cells were identified through univariate analysis. Least absolute shrinkage and selection operator regression analysis was performed to construct the CellAge score and TME score, both of which were identified as independent prognostic factors for HCC based on multivariate Cox analysis. The combined CellAge and TME scores showed improved prognostic stratification for HCC patients, as confirmed by multivariate Cox analysis (p < .001). The gene set enrichment analysis (GSEA) revealed enrichment of the extracellular matrix receptor interaction signaling pathway in the group with high CellAge scores and low TME scores, which exhibited a worse prognosis. Single-cell sequencing results revealed higher expression activity of the cAMP response element modulator (CREM) extended transcription factor in HCC cells and most immune cells, indicating its involvement in TME remodeling. Finally, the tumor immune dysfunction and exclusion (TIDE) analysis demonstrated that the combined scores could predict the outcomes of immune therapy in patients with HCC. In conclusion, cellular senescence contributes to TME remodeling in HCC, and the developed CellAge and TME scores serve as independent prognostic factors and predictors of immune therapy in HCC.

Image processing and supervised machine learning for retinal microglia characterization in senescence.

The process of senescence impairs the function of cells and can ultimately be a key factor in the development of disease. With an aging population, senescence-related diseases are increasing in prevalence. Therefore, understanding the mechanisms of cellular senescence within the central nervous system (CNS), including the retina, may yield new therapeutic pathways to slow or even prevent the development of neuro- and retinal degenerative diseases. One method of probing the changing functions of senescent retinal cells is to observe retinal microglial cells. Their morphological structure may change in response to their surrounding cellular environment. In this chapter, we show how microglial cells in the retina, which are implicated in aging and diseases of the CNS, can be identified, quantified, and classified into five distinct morphotypes using image processing and supervised machine learning algorithms. The process involves dissecting, staining, and mounting mouse retinas, before image capture via fluorescence microscopy. The resulting images can then be classified by morphotype using a support vector machine (SVM) we have recently described showing high accuracy. This SVM model uses shape metrics found to correspond with qualitative descriptions of the shape of each morphotype taken from existing literature. We encourage more objective and widespread use of methods of quantification such as this. We believe automatic delineation of the population of microglial cells in the retina, could potentially lead to their use as retinal imaging biomarkers for disease prediction in the future.

Иммуновоспалительные механизмы старения мочевого пузыря.

Introduction. Despite the absence of a generally accepted theory explaining the mechanisms of aging, existing scientific data indicate a close relationship between aging and chronic low-grade inflammation (low-grade inflammation). This theory of inflammatory aging (inflame-aging) suggests that aging is accompanied by the development of a chronic inflammatory phenotype, which ultimately leads to fibroplastic transformation of tissues, which manifests itself in a functional deficiency of organs and, in particular, the bladder. Aims. To study the role of free radical oxidation, endothelial dysfunction and low-level age-associated inflammation as universal mechanisms of cellular senescence in the process of age-related detrusor rearrangement in experimental animals. Materials and methods. Two groups of laboratory animals were used in the experiment: group 1 (30-month-old white mongrel rats, n=10) and group 2 (10- month-old white mongrel rats, n=10). Markers of low-level age-associated inflammation (TNF-α, IL-6, IL1RA), endothelial dysfunction (ET-1, IL-1β, ESM1), profibrotic status (TGF beta 1 and CTGF), and free radical oxidation (8-isoprostane) were determined in blood and bladder homogenate, malonic dialdehyde, diene conjugates).The Student's criterion was used to compare two groups with a normal distribution. Results and discussion. It was shown that with age in experimental animals, the levels of inflammation markers (TNF-α, IL-6, IL1RA), endothelial dysfunction (ET-1, IL-1β, ESM1), lipid peroxidation (diene conjugates, silicone dialdehyde) and profibrotic cytokines (TGF beta 1 and CTGF) increased, while the levels of antioxidant activity (catalase) decreased statistically significantly.This pattern was revealed both at the systemic (blood plasma) and organ levels (bladder wall). Conclusion. The results of our experimental study confirm the role of chronic low-level inflammation in fibrosis-mediated inflammatory aging of organs and, in particular, in age-associated bladder reconstruction.

Non-Intrinsic, Systemic Mechanisms of Cellular Senescence.

Cellular senescence is believed to contribute to aging and disease through the activity of secreted factors that promote inflammation, remodel the extracellular matrix, and adversely modify the behavior of non-senescent cells. While the markers and properties of senescent cells are still under investigation, it is postulated that cellular senescence manifests in vivo as the consequence of cellular damage that accumulates and becomes exacerbated with time. Yet, the notions that senescence has a solely intrinsic and time-dependent nature are questioned by the rapid induction of senescence in young mice and young cells in vitro by exposure to blood from aged animals. Here, we review some of the research on the systemically present factors that increase with age and may contribute to extrinsically induced senescence or "bystander senescence". These include proteins, reactive oxygen species, lipids, and nucleic acids, which may be present in individual soluble form, in vesicles, and in non-membranous multi-component macromolecules.

LEF1 isoforms regulate cellular senescence and aging.

The study of aging and its mechanisms, such as cellular senescence, has provided valuable insights into age-related pathologies, thus contributing to their prevention and treatment. The current abundance of high-throughput data combined with the surge of robust analysis algorithms has facilitated novel ways of identifying underlying pathways that may drive these pathologies. For the purpose of identifying key regulators of lung aging, we performed comparative analyses of transcriptional profiles of aged versus young human subjects and mice, focusing on the common age-related changes in the transcriptional regulation in lung macrophages, T cells, and B immune cells. Importantly, we validated our findings in cell culture assays and human lung samples. Our analysis identified lymphoid enhancer binding factor 1 (LEF1) as an important age-associated regulator of gene expression in all three cell types across different tissues and species. Follow-up experiments showed that the differential expression of long and short LEF1 isoforms is a key regulatory mechanism of cellular senescence. Further examination of lung tissue from patients with idiopathic pulmonary fibrosis, an age-related disease with strong ties to cellular senescence, revealed a stark dysregulation of LEF1. Collectively, our results suggest that LEF1 is a key factor of aging, and its differential regulation is associated with human and murine cellular senescence.

Anti-aging Factor GRSF1 Attenuates Cerebral Ischemia-Reperfusion Injury in Mice by Inhibiting GPX4-Mediated Ferroptosis.

Abnormal accumulation of senescent cells in tissues has been shown to facilitate the onset and progression of various diseases. As an important protein involving in the regulation of cellular senescence process, researches suggested GRSF1 as a potential senolytic target to improve multiple physiological and pathological processes. However, the underlying mechanism of cellular senescence on cerebral ischemia-reperfusion injury (CIRI) has not been revealed. Here, we investigated the effect of GRSF1 on CIRI and delved into its specific mechanisms. In the present study, we established a mouse model of cerebral ischemia-reperfusion (CIR) and observed low expression of anti-aging factor GRSF1, along with greatly increased levels of senescence-related markers p16 and p21 and senescence-associated secretory phenotype TNF-α. Furthermore, we found that the expression of GPX4 was elevated parallel to GRSF1 in CIR mice with overexpression of GRSF1, oxidative stress, and iron metabolism-related proteins were inhibited. Functionally, overexpressing GRSF1 significantly ameliorated infarct volume and neurological function scores and suppressed apoptosis in CIR mice, while administration of GPX4 inhibitors reversed these beneficial phenotypes. Taken together, our results indicate cellular senescence as an important pathological mechanism to exacerbate cerebral injury during CIRI, while GRSF1 could inhibit oxidative stress-mediated ferroptosis through upregulating GPX4 to attenuate reperfusion injury, which makes senolytic treatment, especially GRSF1, a promising therapeutic target for CIRI.

Tau protein modulates an epigenetic mechanism of cellular senescence in human SH-SY5Y neuroblastoma cells.

Introduction: Progressive Tau deposition in neurofibrillary tangles and neuropil threads is the hallmark of tauopathies, a disorder group that includes Alzheimer's disease. Since Tau is a microtubule-associated protein, a prevalent concept to explain the pathogenesis of tauopathies is that abnormal Tau modification contributes to dissociation from microtubules, assembly into multimeric β-sheets, proteotoxicity, neuronal dysfunction and cell loss. Tau also localizes in the cell nucleus and evidence supports an emerging function of Tau in DNA stability and epigenetic modulation. Methods: To better characterize the possible role of Tau in regulation of chromatin compaction and subsequent gene expression, we performed a bioinformatics analysis of transcriptome data obtained from Tau-depleted human neuroblastoma cells. Results: Among the transcripts deregulated in a Tau-dependent manner, we found an enrichment of target genes for the polycomb repressive complex 2. We further describe decreased cellular amounts of the core components of the polycomb repressive complex 2 and lower histone 3 trimethylation in Tau deficient cells. Among the de-repressed polycomb repressive complex 2 target gene products, IGFBP3 protein was found to be linked to increased senescence induction in Tau-deficient cells. Discussion: Our findings propose a mechanism for Tau-dependent epigenetic modulation of cell senescence, a key event in pathologic aging.

Impact of Aging and Cellular Senescence in the Pathophysiology of Preeclampsia.

The incidence of hypertensive disorders of pregnancy is increasing, which may be due to several factors, including an increased age at pregnancy and more comorbid health conditions during reproductive years. Preeclampsia, the most severe hypertensive disorder of pregnancy, has been associated with an increased risk of future disease, including cardiovascular and kidney diseases. Cellular senescence, the process of cell cycle arrest in response to many physiologic and maladaptive stimuli, may play an important role in the pathogenesis of preeclampsia and provide a mechanistic link to future disease. In this article, we will discuss the pathophysiology of preeclampsia, the many mechanisms of cellular senescence, evidence for the involvement of senescence in the development of preeclampsia, as well as evidence that cellular senescence may link preeclampsia to the risk of future disease. Lastly, we will explore how a better understanding of the role of cellular senescence in preeclampsia may lead to therapeutic trials. © 2023 American Physiological Society. Compr Physiol 13:5077-5114, 2023.

YPEL3 expression induces cellular senescence via the Hippo signaling pathway in human breast cancer cells.

The Hippo pathway is a signaling pathway that controls organ size in animals by regulating cell proliferation and apoptosis. Yes-associated protein 1 (YAP1), an oncogene associated with the development and progression of breast cancer, is downregulated by the Hippo pathway and is associated with the development and progression of breast cancer. Yippee-like 3 (YPEL3) is a target gene of the tumor suppressor protein p53, and its activation has been shown to inhibit cell growth, induce cellular senescence, and suppress tumor cell metastasis. In this study, we found that YAP1 inhibits the expression of YPEL3 expression in breast cancer cells. Furthermore, a decrease in lamin B1, a marker protein of cellular senescence, coupled with the activation of senescence-associated β-galactosidase indicated that upregulating YPEL3 levels through YAP1 downregulation can induce cellular senescence. Additionally, elevated YPEL3 levels resulted in higher levels of oxygen consumption rate in mitochondria, thus promoting apoptosis. This suggests that YPEL3 plays a crucial role in regulating oxidative stress and cell apoptosis in breast cancer cells. Therefore, the interaction between YAP1 and YPEL3 represents a novel mechanism of cellular senescence mediated by the Hippo signaling pathway. Collectively, our findings suggest that the Hippo signaling pathway plays an important role in regulating cellular senescence, which could have implications for the development of new therapeutic strategies for diseases such as cancer.

C-Jun N-terminal kinase signaling in cellular senescence.

Cellular senescence leads to decreased tissue regeneration and inflammation and is associated with diabetes, neurodegenerative diseases, and tumorigenesis. However, the mechanisms of cellular senescence are not fully understood. Emerging evidence has indicated that c-Jun N-terminal kinase (JNK) signaling is involved in the regulation of cellular senescence. JNK can downregulate hypoxia inducible factor-1α to accelerate hypoxia-induced neuronal cell senescence. The activation of JNK inhibits mTOR activity and triggers autophagy, which promotes cellular senescence. JNK can upregulate the expression of p53 and Bcl-2 and accelerates cancer cell senescence; however, this signaling also mediates the expression of amphiregulin and PD-LI to achieve cancer cell immune evasion and prevents their senescence. The activation of JNK further triggers forkhead box O expression and its target gene Jafrac1 to extend the lifespan of Drosophila. JNK can also upregulate the expression of DNA repair protein poly ADP-ribose polymerase 1 and heat shock protein to delay cellular senescence. This review discusses recent advances in understanding the function of JNK signaling in cellular senescence and includes a comprehensive analysis of the molecular mechanisms underlying JNK-mediated senescence evasion and oncogene-induced cellular senescence. We also summarize the research progress in anti-aging agents that target JNK signaling. This study will contribute to a better understanding of the molecular targets of cellular senescence and provides insights into anti-aging, which may be used to develop drugs for the treatment of aging-related diseases.

#5865 BET INHIBITION DIMINISHES CELLULAR SENESCENCE IN CULTURED TUBULAR EPITHELIAL CELLS

Abstract Background and Aims Chronic kidney disease (CKD) can be considered an age-related disorder. Recent studies have shown the involvement of the activation of cellular senescence mechanisms in the kidney and aging. Intensive research to develop pharmacological approaches targeting cellular senescence is under investigation. Among novel therapeutic options, epigenetic drugs, such as bromodomain and extra terminal BET inhibitors, are being widely explored in proliferative, immune and chronic inflammatory diseases, including CKD. These drugs regulate transcription activation of cell cycle control and proinflammatory factors. There are not studies about the potential effect of BET inhibitors on cellular senescence in the kidney despite the fact that tubular epithelial cells are frequently implicated in kidney senescence. Method To study this, we evaluate the effect of JQ1, a BET inhibitor, on cellular senescence in primary cell culture of murine tubular epithelial cells (TECs) using Adriamycin as a senescence inducer verified by B-galactosidase assay. Next, we evaluated the effect of JQ1 on gene expression levels of cell cycle markers, components of senescence-associated secretory phenotype (SASP) as well as anti-apoptotic and antioxidant markers, all of them related to senescence program. Results Our results indicated that JQ1 significantly decreased Adriamycin-induced p21 gene upregulation, a primordial cell cycle arrest factor. This BET inhibitor also downregulated SAPS genes, such as Tgfb1, Il1b, Ctgf, Ccl2 and Il6 overexpression in Adriamycin-treated tubular cells. Likewise, anti-apoptotic Bcl-xl and antioxidant factors Cat, Hmox-1, Nox-4 and Nrf2 mRNA levels were significantly restored by JQ1. Conclusion In conclusion, the present study highlights the use of JQ1 as a therapeutic option to ameliorate tubular cellular senescence-associated markers. These data support the potential use of BET inhibitors in chronic kidney diseases.

#3612 STING IS INVOLVED IN THE CELLULAR SENESCENCE PROCESS ASSOCIATED WITH RENAL AGING

Abstract Background and Aims Cellular senescence is an adaptative process in response to damage or stress. It consists of a cell-cycle-arrest (CCA) alternatively to the programmed cell death process, which is necessary for the regeneration of damaged tissues. However, permanent senescence promotes an aberrant inflammatory response associated to chronic diseases, fibrosis and aging. One of the mechanisms which triggers cellular senescence is the DNA damage response (DDR) activation, that leads to the emergence of a cellular senescence-associated secretory phenotype (SASP), inflammation and fibrosis. Sting is a detection protein of pathogenic DNA derived from cellular damage and genotoxic and environmental stresses, starting an innate immune response and inflammation. A deregulated DDR response and thus the process of senescence itself, are also able to activate Sting. Nevertheless, the role of Sting in senescence associated to renal aging is an unknown fact. The aim of this study is to evaluate the role of STING in aging-associated pathophysiological changes in the kidney. Method Studies were carried out in C57BL76 mice (wild type mice) and in mice with a phenotype deficient in the Sting gene (KO-Sting), of different ages: 3 (young) and 18 (aged) months. Renal function parameters, histology and markers of kidney damage, and activation of cellular senescence in presence or absence of Sting were studied. Results C57BL76 mice of 18 month presented renal dysfunction and fibrosis that was not observed in KO-Sting mice of the same age. Interestingly, 18 months wild-type mice showed an activation of the Sting pathway, characterized by increased transcriptional levels of Ifit1, Oasl2, Usp19 and Mx2. Moreover, the activation of STING pathway was associated to activation of cellular senescence mechanisms, including elevated renal gene expression of SASP components, such as Ccl2, Ccn2, Il1β, Il6, Pai1 or Tgf-β. Importantly, in Sting KO mice of 18 months, DNA damage response was not activated (no increase in ɣH2AX) and cell cycle arrest was not induced, as determined by the p21 and p16 markers. In addition, SAPS gene expression remained at basal levels in aged KO-Sting mice. However, Klotho gene expression levels are downregulated in all 18-month-old mice, wild type and KO mice. Conclusion In conclusion, these findings suggest that the absence of STING prevents age-related renal cellular senescence in a Klotho independent manner in a murine experimental model.

Integrated bioinformatics and machine learning algorithms reveal the critical cellular senescence-associated genes and immune infiltration in heart failure due to ischemic cardiomyopathy.

Heart failure (HF) is the final stage of many cardiovascular illnesses and the leading cause of death worldwide. At the same time, ischemic cardiomyopathy has replaced valvular heart disease and hypertension as the primary causes of heart failure. Cellular senescence in heart failure is currently receiving more attention. In this paper, we investigated the correlation between the immunological properties of myocardial tissue and the pathological mechanisms of cellular senescence during ischemic cardiomyopathy leading to heart failure (ICM-HF) using bioinformatics and machine learning methodologies. Our goals were to clarify the pathogenic causes of heart failure and find new treatment options. First, after obtaining GSE5406 from the Gene Expression Omnibus (GEO) database and doing limma analysis, differential genes (DEGs) among the ICM-HF and control groups were identified. We intersected these differential genes with cellular senescence-associated genes (CSAG) via the CellAge database to obtain 39 cellular senescence-associated DEGs (CSA-DEGs). Then, a functional enrichment analysis was performed to elucidate the precise biological processes by which the hub genes control cellular senescence and immunological pathways. Then, the respective key genes were identified by Random Forest (RF) method, LASSO (Least Absolute Shrinkage and Selection Operator) algorithms, and Cytoscape's MCODE plug-in. Three sets of key genes were taken to intersect to obtain three CSA-signature genes (including MYC, MAP2K1, and STAT3), and these three CSA-signature genes were validated in the test gene set (GSE57345), and Nomogram analysis was done. In addition, we assessed the relationship between these three CSA- signature genes and the immunological landscape of heart failure encompassing immunological infiltration expression profiles. This work implies that cellular senescence may have a crucial role in the pathogenesis of ICM-HF, which may be closely tied to its effect on the immune microenvironment. Exploring the molecular underpinnings of cellular senescence during ICM-HF is anticipated to yield significant advances in the disease's diagnosis and therapy.

The Cross Talk between Cellular Senescence and Melanoma: From Molecular Pathogenesis to Target Therapies.

Melanoma is a malignant skin tumor that originates from melanocytes. The pathogenesis of melanoma involves a complex interaction that occurs between environmental factors, ultraviolet (UV)-light damage, and genetic alterations. UV light is the primary driver of the skin aging process and development of melanoma, which can induce reactive oxygen species (ROS) production and the presence of DNA damage in the cells, and results in cell senescence. As cellular senescence plays an important role in the relationship that exists between the skin aging process and the development of melanoma, the present study provides insight into the literature concerning the topic at present and discusses the relationship between skin aging and melanoma, including the mechanisms of cellular senescence that drive melanoma progression, the microenvironment in relation to skin aging and melanoma factors, and the therapeutics concerning melanoma. This review focuses on defining the role of cellular senescence in the process of melanoma carcinogenesis and discusses the targeting of senescent cells through therapeutic approaches, highlighting the areas that require more extensive research in the field.

Epigenetic and non-epigenetic mechanisms in the accelerated cellular aging in late-onset Alzheimer’s disease

Late-onset Alzheimer’s disease (LOAD) is the most common form of Alzheimer’s disease (AD) and its risk increases exponentially with aging. The incidence of LOAD is reported to increase from 1 in every 1,000 people aged 37 to 65 in every 100 people aged 80 years and older. LOAD is extensively associated with aging and cognition decline. Several risk factors, including lifestyle choices, environmental factors, and medical ailments, affect cellular stress. The cellular stress can bring upon epigenetic alterations that affect cellular aging making the individual more susceptible to LOAD development. In due course the cellular stress resulting into epigenetic deregulation, oxidative burden, and genomic mutations leads to increased disease risk. Role of epigenetic and non-epigenetic mechanisms in accelerated cellular aging that are reported to increase the risk of LOAD development are summarized in this review. The underlying biological mechanism of cellular aging and the risk factors that could predispose cellular aging and LOAD development are also discussed in the upcoming sections.

Vitamin D, Cellular Senescence and Chronic Kidney Diseases: What Is Missing in the Equation?

As life expectancy increases in many countries, the prevalence of age-related diseases also rises. Among these conditions, chronic kidney disease is predicted to become the second cause of death in some countries before the end of the century. An important problem with kidney diseases is the lack of biomarkers to detect early damage or to predict the progression to renal failure. In addition, current treatments only retard kidney disease progression, and better tools are needed. Preclinical research has shown the involvement of the activation of cellular senescence-related mechanisms in natural aging and kidney injury. Intensive research is searching for novel treatments for kidney diseases as well as for anti-aging therapies. In this sense, many experimental shreds of evidence support that treatment with vitamin D or its analogs can exert pleiotropic protective effects in kidney injury. Moreover, vitamin D deficiency has been described in patients with kidney diseases. Here, we review recent evidence about the relationship between vitamin D and kidney diseases, explaining the underlying mechanisms of the effect of vitamin D actions, with particular attention to the modulation of cellular senescence mechanisms.

Modulation of Mitochondrial Function in Elderly Brain: Involvement of Autophagy and Apoptosis

Mitochondria are crucial cellular organelles that regulate energy production, oxidative balance, and calcium homeostasis, among other things. Aging is a natural, multifactorial, and multi-organic process, in which both pathological and physiological changes occur gradually over time. Autophagy capacity and mitochondrial processes such as mitophagy, biogenesis, and dynamics are associated with aging. These processes are important for maintaining the structural integrity of mitochondria and thus cell life since mitochondrial dysfunction leads to an impairment in energy metabolism and an increased production of reactive oxygen species, both of which may stimulate mechanisms of cellular senescence and apoptotic cell death. Furthermore, in both model organisms and humans, a decline in mitochondrial activity can contribute to age-related disease phenotypes. As people age, mitochondrial damage and malfunction may induce apoptosis, thus explaining the rise in cell death. Many aging processes are believed to be driven by oxidative stress. Taken together, the evidence strongly suggests a relation between mitochondrial function and a wide spectrum of aging processes. Although there is no general consensus among the studies reviewed, it appears that aging reduces mitochondrial biogenesis and dynamics, as well as the mitophagy capacity of the organism involved. This review describes the involvement of autophagy and apoptosis in the modulation of mitochondrial function in the brain.

Autophagy and senescence of rat retinal precursor cells under high glucose.

Diabetic retinopathy (DR) is a common diabetic ocular disease characterized by retinal ganglion cell (RGC) changes. An abnormal environment, hyperglycemia, may progressively alter the structure and function of RGCs, which is a primary pathological feature of retinal neurodegeneration in DR. Accumulated studies confirmed autophagy and senescence play a vital role in DR; however, the underlying mechanisms need to be clarified. This study included the microarray expression profiling dataset GSE60436 from Gene Expression Omnibus (GEO) to conduct the bioinformatics analysis. The R software was used to identify autophagy-related genes (ARGs) that were differentially expressed in fibrovascular membranes (FVMs) and normal retinas. Co-expression and tissue-specific expression were elicited for the filtered genes. The genes were then analyzed by ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and Gene Set Enrichment Analysis (GSEA). R28 cells were cultured with high glucose, detected by reverse transcription-quantitative (RT-qPCR) and stained by apoptosis kit. In the retina, 31 differentially expressed ARGs (24 up-regulated genes) were discovered and enriched. The enrichment results revealed that differentially expressed ARGs were significantly enriched in autophagy, apoptosis, aging, and neural function. Four hub genes (i.e., TP53, CASP1, CCL2, and CASP1) were significantly up-regulated. Upregulation of cellular autophagy and apoptosis level was detected in the hyperglycemia model in vitro. Our results provide evidence for the autophagy and cellular senescence mechanisms involved in retinal hyperglycemia injury, and the protective function of autophagy is limited. Further study may favour understanding the disease progression and neuroprotection of DR.

ПОЛИМОРФИЗМЫ ГЕНОВ NOS3 И CYBA В РАЗВИТИИ ЦИРРОЗА ПЕЧЕНИ У БОЛЬНЫХ ХРОНИЧЕСКИМ ВИРУСНЫМ ГЕПАТИТОМ В В ЯКУТСКОЙ ПОПУЛЯЦИИ

Chronic viral hepatitis B is a significant public health problem. Hepatitis virus carrier factors affect the course of chronic hepatitis B and odds of progression to liver cirrhosis. So, the research for the early development genetic predictors of complications of chronic hepatitis B is relevant. NOS3 and CYBA genes can act as predictor genes for early fibrotic processes in the liver. Researches confirm the role of oxidative stress and the mechanisms of cellular aging in the development of liver fibrosis. The purpose of this study is to identify the relationship between the carriage of polymorphisms of the NOS3 and CYBA genes and the development of liver fibrosis in patients with chronic viral hepatitis B in the Yakut population. Molecular genetic study of SNPs rs1799983 and rs1801131 of the NOS3 gene, rs4673 of the CYBA gene was carried out on 417 people. The collection of representative material was carried out on the basis of the Infectious Diseases Department of the Yakut Republican Clinical Hospital and the NEFU Clinic. As a result of a genetic study, it was found that in carriers of the mutant allele for the rs1799983 polymorphism of the NOS3 gene, the probability of developing liver cirrhosis is 1.81 times higher (0.176–0.098, CI 95%,), in carriers of the rs4673 mutant allele of the CYBA gene, the probability of developing liver cirrhosis is higher by 1.9 times (0.211–0.111, CI 95%), in carriers of the mutant allele for the rs2070744 polymorphism of the NOS3 gene, the probability of developing liver cirrhosis is 2.03 times higher (0.181–0.089, CI 95%). Thus, the obtained results indicate the need for additional studies of these genes, since they can be predictors of the development of liver cirrhosis in patients with chronic viral hepatitis B in the Yakut population.