Mitochondrion: A bridge linking aging and degenerative diseases

The effect of Hydrogen-rich water on retinal degeneration in the outer nuclear layer of simulated weightlessness rats

Long-term spaceflight can lead to changes in eye structure and decreased visual function. At present, there are almost no effective methods to prevent and treat eye damage caused by microgravity environments. Oxidative stress has been identified as one of the contributing mechanisms of spaceflight-associated neuro-ocular syndrome (SANS), and hydrogen (H2) has demonstrated significant antioxidant and anti-inflammatory effects. The aim of this study was to determine whether hydrogen-rich water (HRW) has a protective effect against eye injury induced by tail-suspension simulated weightlessness in rats, and to elucidate the underlying mechanisms. In this experiment, we utilized an 8-week tail-suspension model to simulate weightlessness, and employed histopathology, visual electrophysiology, and biochemical indices to evaluate retinal structure, function, and related molecular mechanisms leading to retinal damage. We also assessed the therapeutic efficacy of HRW treatment. Results demonstrated that tail-suspension simulated weightlessness induced thinning of the retinal outer nuclear layer, decreased visual function, and promoted retinal inflammation, oxidative stress, and mitochondrial dysfunction in rats. HRW treatment effectively alleviated the degenerative changes in the retinal outer nuclear layer, improved retinal function, and reduced retinal inflammation in treated rats. Our findings revealed that HRW reduced the retinal oxidative stress response and enhanced mitochondrial function through the PI3K/Akt/Nrf2 signaling pathway. Overall, HRW may be a promising candidate for the treatment of eye injuries in simulated microgravity environments.

From Obesity to Mitochondrial Dysfunction in Peripheral Tissues and in the Central Nervous System

Obesity is a condition of chronic low-grade inflammation affecting peripheral organs of the body, as well as the central nervous system. The adipose tissue dysfunction occurring under conditions of obesity is a key factor in the onset and progression of a variety of diseases, including neurodegenerative disorders. Mitochondria, key organelles in the production of cellular energy, play an important role in this tissue dysfunction. Numerous studies highlight the close link between obesity and adipocyte mitochondrial dysfunction, resulting in excessive ROS production and adipose tissue inflammation. This inflammation is transmitted systemically, leading to metabolic disorders that also impact the central nervous system, where pro-inflammatory cytokines impair mitochondrial and cellular functions in different areas of the brain, leading to neurodegenerative diseases. To date, several bioactive compounds are able to prevent and/or slow down neurogenerative processes by acting on mitochondrial functions. Among these, some molecules present in the Mediterranean diet, such as polyphenols, carotenoids, and omega-3 PUFAs, exert a protective action due to their antioxidant and anti-inflammatory ability. The aim of this review is to provide an overview of the involvement of adipose tissue dysfunction in the development of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and multiple sclerosis, emphasizing the central role played by mitochondria, the main actors in the cross-talk between adipose tissue and the central nervous system.

Determination of ADP/ATP translocase isoform ratios in malignancy and cellular senescence

Cellular senescence has recently been recognized as a significant contributor to the poor prognosis of glioblastoma, one of the most aggressive brain tumors. Consequently, effectively eliminating senescent glioblastoma cells could benefit patients. Human ADP/ATP translocases (ANTs) play a role in oxidative phosphorylation in both normal and tumor cells. Previous research has shown that the sensitivity of senescent cells to mitochondria-targeted senolytics depends on the level of ANT2. Here, we systematically mapped the transcript and protein levels of ANT isoforms in various types of senescence and glioblastoma tumorigenesis. We employed bioinformatics analysis, targeted mass spectrometry, RT-PCR, immunoblotting, and assessment of cellular energy state to elucidate how individual ANT isoforms are expressed during the development of senescence in noncancerous and glioblastoma cells. We observed a consistent elevation of ANT1 protein levels across all tested senescence types, while ANT2 and ANT3 exhibited variable changes. Alterations in ANT protein isoform levels correlated with shifts in the cellular oxygen consumption rate. Our findings suggest that ANT isoforms are mutually interchangeable for oxidative phosphorylation and manipulating individual ANT isoforms could have potential for senolytic therapy.

Pharmacological approaches to enhance mitochondrial biogenesis: focus on PGC-1Α, AMPK, and SIRT1 in cellular health

BACKGROUND

Mitochondrial biogenesis is essential for cellular energy balance and metabolic stability. Its dysregulation is linked to various metabolic and neurodegenerative diseases, making it a significant therapeutic target. Pharmacological approaches aimed at enhancing mitochondrial function have gained attention for their potential to restore cellular metabolism.

OBJECTIVES

This review examines recent advancements in pharmacological strategies targeting mitochondrial biogenesis, focusing on the roles of PGC-1α, AMPK, and SIRT1, alongside novel therapeutic agents and drug delivery systems.

METHODS

A systematic review of studies published between 2018 and 2023 was conducted using databases such as PubMed, Web of Science, and Elsevier. Keywords related to mitochondrial biogenesis and pharmacological modulation were used to identify relevant literature.

RESULTS

Various pharmacological agents, including resveratrol, curcumin, and metformin, activate mitochondrial biogenesis through different pathways. SIRT1 activators and AMPK agonists have shown promise in improving mitochondrial function. Advances in mitochondria-targeted drug delivery systems enhance therapeutic efficacy, yet challenges remain in clinical translation due to the complexity of mitochondrial regulation.

CONCLUSION

Pharmacological modulation of mitochondrial biogenesis holds therapeutic potential for metabolic and neurodegenerative diseases. While preclinical studies are promising, further research is needed to optimize drug efficacy, delivery methods, and personalized treatment strategies.

Mitochondrial DNA in atherosclerosis research progress: a mini review

Atherosclerosis (AS) is a chronic inflammatory disease that primarily affects large and medium-sized arteries and is one of the leading causes of death worldwide. This article reviews the multifaceted role of mitochondrial DNA (mtDNA) in AS, including its structure, function, release, and relationship with inflammation. Damage and release of mtDNA are considered central drivers in the development of AS, as they participate in the progression of AS by activating inflammatory pathways and affecting lipid metabolism. Therefore, therapeutic strategies targeting mtDNA and its downstream effects may provide new avenues to address this global health challenge.

A Network Meta-Analysis of Different Psychological Therapies for Death Anxiety in Older Adults

Objective: The purpose of this research was to assess and contrast the impact of psychosocial therapies on older individuals' death anxiety and to offer evidence-based recommendations to both older adults and healthcare professionals. Methods: Randomized controlled trials (RCTs) were collected through a thorough search of multiple databases such as PubMed, Embase, Cochrane Library, Web of Science, Scopus, etc. Review Manager 5.4 was employed to evaluate the caliber of the included studies, and STATA (15.1) was used for data analysis. Results: This study included seven randomized controlled trials with a total of 266 older adults, and the search time ranged from the earliest possible date to July 2024. The results of the Network Meta-Analysis (NMA) showed that the teaching the components of spiritual intelligence therapy significantly reduced death anxiety in the elderly (SUCRA: 99.6%). Conclusion: The network ranking chart showed that the teaching the components of spiritual intelligence therapy as a psychotherapeutic method, had the most superior efficacy in reducing death anxiety in the elderly.

Research on Prediction of Multiple Degenerative Diseases and Biomarker Screening Based on DNA Methylation

The aging process will lead to a gradual functional decline in the human body, and even accelerate a significantly increased risk of degenerative diseases. DNA methylation patterns change markedly with one's age, serving as a biomarker of biological age and closely linked to the occurrence and progression of age-related diseases. Currently, diagnostic methods for individual degenerative diseases are relatively mature. However, aging often accompanies the onset of multiple degenerative diseases, presenting certain limitations in existing diagnostic models. Additionally, some identified DNA methylation biomarkers are typically applicable to only one or a few types of cancer or diseases, further restricting their utility. We endeavor to screen for biomarkers associated with multiple degenerative diseases from the perspective of aging-related co-morbid mechanisms and to perform multiple degenerative disease diagnoses. In this study, we explored research based on methylation correlations and patterns to investigate shared mechanisms across multiple degenerative diseases, identifying a set of biomarkers associated with them. We validated these biomarkers with biological omics analysis and the prediction of multiple classes of degenerative diseases, screened the biomarkers from 600 to 110 by biological omics analysis, and demonstrated the validity and predictive ability of the screened 110 biomarkers. We propose a disease diagnostic model based on a multi-scale one-dimensional convolutional neural network (MSDCNN) and a multi-class degenerative disease prediction model (ResDegNet). The two models are well trained and tested to accurately diagnose diseases and categorize four types of degenerative diseases. The research identified 110 biomarkers associated with degenerative diseases, providing a foundation for further exploration of age-related degenerative conditions. This work aims to facilitate early diagnosis, the identification of biomarkers, and the development of therapeutic targets for drug interventions.

Mitophagy Unveiled: Exploring the Nexus of Mitochondrial Health and Neuroendocrinopathy

Mitochondria play a pivotal role in cellular metabolism, energy production, and apoptotic signaling, making mitophagy, the selective degradation of damaged mitochondria, crucial for mitochondrial health. Dysregulation of mitophagy has been implicated in various neuroendocrinopathies, yet the mechanisms linking these processes remain poorly understood. This review aims to explore the intersection between mitophagy and neuroendocrinopathy, addressing the critical gaps in knowledge regarding how mitochondrial dysfunction may contribute to the pathophysiology of neuroendocrine disorders. We conducted a comprehensive literature review of studies published on mitophagy and neuroendocrinopathies, focusing on data that elucidate the pathways involved and the clinical implications of mitochondrial health in neuroendocrine contexts. Our findings indicate that altered mitophagy may lead to the accumulation of dysfunctional mitochondria, contributing to neuroendocrine dysregulation. We present evidence linking impaired mitochondrial clearance to disease models of conditions such as metabolic syndrome, depression, and stress-related disorders, highlighting the potential for therapeutic interventions targeting mitophagy. While significant advances have been made in understanding mitochondrial biology, the direct interplay between mitophagy and neuroendocrinopathies remains underexplored. This review underscores the necessity for further research to elucidate these connections, which may offer novel insights into disease mechanisms and therapeutic strategies for treating maladaptive neuroendocrine responses.

Targeting lysosomal quality control as a therapeutic strategy against aging and diseases

Previously, lysosomes were primarily referred to as the digestive organelles and recycling centers within cells. Recent discoveries have expanded the lysosomal functional scope and revealed their critical roles in nutrient sensing, epigenetic regulation, plasma membrane repair, lipid transport, ion homeostasis, and cellular stress response. Lysosomal dysfunction is also found to be associated with aging and several diseases. Therefore, function of macroautophagy, a lysosome-dependent intracellular degradation system, has been identified as one of the updated twelve hallmarks of aging. In this review, we begin by introducing the concept of lysosomal quality control (LQC), which is a cellular machinery that maintains the number, morphology, and function of lysosomes through different processes such as lysosomal biogenesis, reformation, fission, fusion, turnover, lysophagy, exocytosis, and membrane permeabilization and repair. Next, we summarize the results from studies reporting the association between LQC dysregulation and aging/various disorders. Subsequently, we explore the emerging therapeutic strategies that target distinct aspects of LQC for treating diseases and combatting aging. Lastly, we underscore the existing knowledge gap and propose potential avenues for future research.

Mitochondria: fundamental characteristics, challenges, and impact on aging

As one of the most vital organelles within biological cells, mitochondria hold an irreplaceable status and play crucial roles in various diseases. Research and therapies targeting mitochondria have achieved significant progress in numerous conditions. Throughout an organism's lifespan, mitochondrial dynamics persist continuously, and due to their inherent characteristics and various external factors, mitochondria are highly susceptible to damage. This susceptibility is particularly evident during aging, where the decline in biological function is closely intertwined with mitochondrial dysfunction. Despite being an ancient and enigmatic organelle, much remains unknown about mitochondria. Here, we will explore the past and present knowledge of mitochondria, providing a comprehensive review of their intrinsic properties and interactions with nuclear DNA, as well as the challenges and impacts they face during the aging process.

Prevalence and pattern of multimorbidity in China: a cross-sectional study of 224,142 adults over 60 years old

Aim

To examine the prevalence and potential risk factors of multimorbidity among older adult in China. In addition, we investigated the pattern of multimorbidity.

Methods

This study is based on data from the fourth Sample Survey of the Aged Population in Urban and Rural China (SSAPUR) in 2015, a comprehensive survey of individuals aged 60 years or older in China. We calculated baseline data and prevalence rates for comorbidities, stratified by household registration, age, sex, education, exercise, and health insurance. Univariate and multivariate logistic regression analyses were conducted to identify potential risk factors for comorbidities. Furthermore, we determined the prevalence rates for the three most frequent disease combinations.

Results

A total of 215,040 participants were included in our analysis. The prevalence of multimorbidity was 50.5% among the older adult in China. The prevalence rate was slightly higher in rural areas than in urban areas, with rates of 51.5 and 49.6%, respectively (p < 0.001). Moreover, the prevalence rate was higher in females than in males, with rates of 55.2 and 45.3%, respectively (p < 0.001). Multivariate logistic regression analysis revealed that individuals aged 70-79 years (OR:1.40, 95% CI: 1.38-1.43, p < 0.001) and over 80 years (OR:1.41, 95% CI: 1.38-1.45, p < 0.001) had a higher prevalence of multimorbidity than those aged 60-69 years. The most prevalent pair of comorbidities was hypertension and osteoarthropathy, with 19.6% of the participants having these two conditions, accounting for 5.4% of the total participants.

Conclusion

Our findings indicate a high prevalence of multimorbidity among the older adult in China. Increased expenditure on preventive health care, popularization of general medicine and popular medical education may be adopted by the Government to cope with the high prevalence of multimorbidity.

Mitochondria-Targeted Delivery Strategy of Dual-Loaded Liposomes for Alzheimer's Disease Therapy

Liposomes modified with tetradecyltriphenylphosphonium bromide with dual loading of α-tocopherol and donepezil hydrochloride were successfully designed for intranasal administration. Physicochemical characteristics of cationic liposomes such as the hydrodynamic diameter, zeta potential, and polydispersity index were within the range from 105 to 115 nm, from +10 to +23 mV, and from 0.1 to 0.2, respectively. In vitro release curves of donepezil hydrochloride were analyzed using the Korsmeyer-Peppas, Higuchi, First-Order, and Zero-Order kinetic models. Nanocontainers modified with cationic surfactant statistically better penetrate into the mitochondria of rat motoneurons. Imaging of rat brain slices revealed the penetration of nanocarriers into the brain. Experiments on transgenic mice with an Alzheimer's disease model (APP/PS1) demonstrated that the intranasal administration of liposomes within 21 days resulted in enhanced learning abilities and a reduction in the formation rate of Aβ plaques in the entorhinal cortex and hippocampus of the brain.

Modulation of Mitochondrial Function as a Therapeutic Strategy for Neurodegenerative Diseases

Despite recent FDA approval of anti-amyloid antibodies for Alzheimer's Disease, strategies that target early molecular mechanisms and could delay or change the disease trajectory are still needed. Mitochondria emerge as a signaling organelle that could modulate multiple molecular mechanisms to enhance cellular bioenergetics and promote neuronal survival. Approaches to enhance mitochondrial function could promote healthy aging delaying the onset of age-related diseases such as Alzheimer's Disease. Some of these strategies have been recently tested in clinical trials. Emerging evidence demonstrates that in response to mild energetic stress, mitochondria could orchestrate a robust adaptive stress response activating multiple neuroprotective mechanism. The objective of this review is to highlight recent development of mitochondria-targeting therapeutics for neurodegenerative diseases, mitochondria complex I inhibitors in particular.