Sirt1 and the Mitochondria

DEHP regulates ferritinophagy to promote testicular ferroptosis via suppressing SIRT1/PGC-1α pathway

To increase elasticity and flexibility, di-2-ethylhexyl phthalate (DEHP) is used in a variety of industrial products, but excessive exposure to it can pose a threat to human health. In epidemiological studies of population exposure to DEHP, attention has been paid to damage to the male reproductive system. However, the toxicological mechanism of DEHP regarding testicular injury is not well understood. We used Western blot analysis, transmission electron microscopy, fluorescence staining, transient transfection and assay kit to detect relevant indicators, and the results were as follows: After DEHP exposure, the expression levels of ACSL4, COX2, TF, FTH1, LC3, AMPK, p-AMPK, ULK1, p-ULK1, serum iron, tissue iron and MDA in the exposure group were significantly increased. The expression levels of GPX4, NCOA4, p62, SIRT1, and PGC-1α, as well as the contents of GSH and ATP, decreased. Electron microscopy showed that more autophagosomes were observed. Our findings suggest that exposure to DEHP induced ferritinophagy and ferroptosis in the testis. In vitro, the promoting effect of ferritinophagy on ferroptosis was verified by applying the autophagy inhibitor (3-MA) and si-NCOA4. Moreover, Mono-(2-ethylhexyl) phthalate (MEHP) inhibited the mitochondrial regulatory protein SIRT1/PGC-1α, leading to mitochondrial dysfunction. Changes in mitochondrial reactive oxygen species (MtROS) and energy over-activated AMPK/ULK1 autophagy pathway, and then promoted ferritinophagy, which increased the sensitivity of TM4 cells to ferroptosis. This research offers a theoretical framework for the prevention and management of DEHP-induced harm.

Renal denervation improves mitochondrial oxidative stress and cardiac hypertrophy through inactivating SP1/BACH1-PACS2 signaling

BACKGROUND

Renal denervation (RDN) has been proved to relieve cardiac hypertrophy; however, its detailed mechanisms remain obscure. This study investigated the detailed protective mechanisms of RDN against cardiac hypertrophy during hypertensive heart failure (HF).

METHODS

Male 5-month-old spontaneously hypertension (SHR) rats were used in a HF rat model, and male Wistar-Kyoto (WKY) rats of the same age were used as the baseline control. Myocardial hypertrophy and fibrosis were evaluated by hematoxylin-eosin (HE) staining and Masson staining. The expression of target molecule was analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western blot, immunohistochemical and immunofluorescence, respectively. Cardiomyocyte hypertrophy was induced by norepinephrine (NE) in H9c2 cells in vitro and evaluated by brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), β-myosin heavy chain (β-MHC), and α-myosin heavy chain (α-MHC) levels. Oxidative stress was determined by malondialdehyde (MDA) level, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) enzyme activities. Mitochondrial function was measured by mitochondrial membrane potential, adenosine triphosphate (ATP) production, mitochondrial DNA (mtDNA) number, and mitochondrial complex I-IV activities. Molecular mechanism was assessed by dual luciferase reporter and chromatin immunoprecipitation (ChIP) assays.

RESULTS

RDN decreased sympathetic nerve activity, attenuated myocardial hypertrophy and fibrosis, and improved cardiac function in the rat model of HF. In addition, RDN ameliorated mitochondrial oxidative stress in myocardial tissues as evidenced by reducing MDA and mitochondrial reactive oxygen species (ROS) levels, and enhancing SOD and GSH-Px activities. Moreover, phosphofurin acid cluster sorting protein 2 (PACS-2) and broad-complex, tramtrak and bric à brac (BTB) domain and cap'n'collar (CNC) homolog 1 (BACH1) were down-regulated by RDN. In NE-stimulated H9c2 cells, PACS-2 and BACH1 levels were markedly elevated, and knockdown of them could suppress NE-induced oxidative stress, cardiomyocyte hypertrophy, fibrosis, as well as mitochondrial dysfunction. Transforming growth factor beta1(TGFβ1)/SMADs signaling pathway was inactivated by RDN in the HF rats, which sequentially inhibited specificity protein 1 (SP1)-mediated transcription of PACS2 and BACH1.

CONCLUSION

Collectively, these data demonstrated that RDN improved cardiac hypertrophy and sympathetic nerve activity of HF rats via repressing BACH1 and PACS-2-mediated mitochondrial oxidative stress by inactivating TGF-β1/SMADs/SP1 pathway, which shed lights on the cardioprotective mechanism of RDN in HF.

Unveiling the Longevity Potential of Natural Phytochemicals: A Comprehensive Review of Active Ingredients in Dietary Plants and Herbs

Ancient humans used dietary plants and herbs to treat disease and to pursue eternal life. Today, phytochemicals in dietary plants and herbs have been shown to be the active ingredients, some of which have antiaging and longevity-promoting effects. Here, we summarize 210 antiaging phytochemicals in dietary plants and herbs, systematically classify them into 8 groups. We found that all groups of phytochemicals can be categorized into six areas that regulate organism longevity: ROS levels, nutrient sensing network, mitochondria, autophagy, gut microbiota, and lipid metabolism. We review the role of these processes in aging and the molecular mechanism of the health benefits through phytochemical-mediated regulation. Among these, how phytochemicals promote longevity through the gut microbiota and lipid metabolism is rarely highlighted in the field. Our understanding of the mechanisms of phytochemicals based on the above six aspects may provide a theoretical basis for the further development of antiaging drugs and new insights into the promotion of human longevity.

Alpha-Linolenic Acid Supplementation Improves Testosterone Production in an Aged Breeder Rooster Model: Role of Mitochondrial Modulation and SIRT1 Activation

SCOPE

Aging in males can lead to declines in testosterone production, essential for maintaining male reproductive health.

METHODS AND RESULTS

To investigate the effects of dietary supplementation with alpha-linolenic acid (ALA) on testosterone production in aged breeder roosters and understand the underlying molecular mechanisms involved. An in vivo model is established to investigate the effects of dietary ALA supplementation on testosterone production in aged breeder roosters, and the Leydig cell culture is used to identify the potential molecular mechanism. Dietary supplementation with ALA increases in plasma testosterone. Congruently, ALA supplementation enhances the expression of testosterone biosynthesis-related enzymes. ALA supplementation exerts anti-apoptotic effects in testicular mitochondria, as evidenced by a lower expression of pro-apoptotic factors and a higher expression of the anti-apoptotic factor B-cell lymphoma 2 (Bcl-2). Moreover, In Leydig cells, ALA supplementation promotes mitochondrial biogenesis genes. The proposed mechanism is that ALA activates the sirtuin1 (SIRT1) pathway and is supported by higher SIRT1 transcript and protein in Leydig cells. Furthermore, blocking SIRT1 with siRNA reverses ALA's effects on testosterone biosynthesis and mitochondrial function-related genes.

CONCLUSION

These findings indicate that dietary supplementation with ALA can improve testosterone production in aged breeder roosters, possibly by modulation of mitochondrial function via activating the SIRT1 pathway.

Antifreeze protein type I in the vitrification solution improves the cryopreservation of immature cat oocytes

Oocyte cryopreservation is not yet considered a reliable technique since it can reduce the quality and survival of oocytes in several species. This study determined the effect of different concentrations of antifreeze protein I (AFP I) on the vitrification solution of immature cat oocytes. For this, oocytes were randomly distributed in three groups and vitrified with 0 μg/mL (G0, 0 μM); 0.5 μg/mL (G0.5, 0.15 μM), or 1 μg/mL (G1, 0.3 μM) of AFP I. After thawing, oocytes were evaluated for morphological quality, and compared to a fresh group (FG) regarding actin integrity, mitochondrial activity and mass, reactive oxygen species (ROS) and glutathione (GSH) levels, nuclear maturation, expression of GDF9, BMP15, ZAR-1, PRDX1, SIRT1, and SIRT3 genes (normalized by ACTB and YWHAZ genes), and ultrastructure. G0.5 and G1 presented a higher proportion of COCs graded as I and while G0 had a significantly lower quality. G1 had a higher percentage of intact actin in COCs than G0 and G0.5 (P < 0.05). There was no difference (P > 0.05) in the mitochondrial activity between FG and G1 and they were both higher (P < 0.05) than G0 and G0.5. G1 had a significantly lower (P < 0.05) mitochondrial mass than FG and G0, and there was no difference among FG, G0, and G0.5. G1 had higher ROS than all groups (P < 0.05), and there was no difference in GSH levels among the vitrified groups (P > 0.05). For nuclear maturation, there was no difference between G1 and G0.5 (P > 0.05), but these were both higher (P < 0.05) than G0 and lower (P < 0.05) compared to FG. Regarding gene expression, in G0 and G0.5, most genes were downregulated compared to FG, except for SIRT1 and SIRT3 in G0 and SIRT3 in G0.5. In addition, G1 kept the expression more similar to FG. Regardless of concentration, AFP I supplementation in vitrification solution of immature cat oocytes improved maturation rates, morphological quality, and actin integrity and did not impact GSH levels. In the highest concentration tested (1 μg/mL), AFP maintained the mitochondrial activity, reduced mitochondrial mass, increased ROS levels, and had the gene expression more similar to FG. Altogether these data show that AFP supplementation during vitrification seems to mitigate some of the negative impact of cryopreservation improving the integrity and cryosurvival of cat oocytes.

The Role of Non-Coding RNAs in Mitochondrial Dysfunction of Alzheimer's Disease

Although brain amyloid-β (Aβ) peptide buildup is the main cause of Alzheimer's disease (AD), mitochondrial abnormalities can also contribute to the illness's development, as either a primary or secondary factor, as programmed cell death and efficient energy generation depend on the proper operation of mitochondria. As a result, non-coding RNAs (ncRNAs) may play a crucial role in ensuring that nuclear genes related to mitochondria and mitochondrial genes function normally. Interestingly, a significant number of recent studies have focused on the impact of ncRNAs on the expression of nucleus and mitochondrial genes. Additionally, researchers have proposed some intriguing therapeutic approaches to treat and reduce the severity of AD by adjusting the levels of these ncRNAs. The goal of this work was to consolidate the existing knowledge in this field of study by systematically investigating ncRNAs, with a particular emphasis on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs). Therefore, the impact and processes by which ncRNAs govern mitochondrial activity in the onset and progression of AD are thoroughly reviewed in this article. Collectively, the effects of ncRNAs on physiological and molecular mechanisms associated with mitochondrial abnormalities that exacerbate AD are thoroughly reviewed in the current research, while also emphasizing the relationship between disturbed mitophagy in AD and ncRNAs.

Effect of Nicotinamide Riboside Against the Exhaustion of CD8+ T Cells via Alleviating Mitochondrial Dysfunction

Background: Targeting mitochondria and protecting the mitochondrial function of CD8+ T cells are crucial for enhancing the clinical efficacy of cancer immunotherapy. Objectives: In this study, our objective was to investigate the potential of nicotinamide riboside (NR) in preserving the mitochondrial function of CD8+ T cells and mitigating their exhaustion. Methods: We established two in vitro models to induce CD8+ T cell exhaustion either by tumor cell-conditioned medium (TCM) or by continuous stimulation with OVA(257-264) peptide. CD8+ T cells were treated in the absence/presence of NR. Results: Our findings demonstrated that NR supplementation effectively inhibited CD8+ T cell exhaustion and preserved mitochondrial function in both models. Moreover, apoptosis of CD8+ T cells was reduced after NR treatment. Western blot data indicated that NR treatment upregulated Silent information regulator 1 (SirT1) expression. Further inhibition of Sirt1 activity using EX527 uncovered that the inhibitory effect of NR on CD8+ T cell exhaustion and its protective effect on mitochondria were attenuated. Conclusions: In conclusion, our results indicate that NR supplementation attenuates CD8+ T cell exhaustion, and its underlying mechanism is associated with increased mitochondrial function regulated by the SirT1 pathway. Our research provides evidence that NR may assist in enhancing the clinical efficacy of immunotherapy.

More than a mutagenic Aflatoxin B1 precursor: The multiple cellular targets of Versicolorin A revealed by global gene expression analysis

Versicolorin A (VerA), a precursor of the potent carcinogen Aflatoxin B1 (AFB1), is an emerging mycotoxin. Recent research has highlighted the mutagenic and genotoxic properties of VerA, yet several facets of its pronounced toxicity remain unexplored. In the present study, we investigated early (6 h) transcriptomic changes induced by VerA in differentiated intestinal cells in non-cytotoxic conditions (1 and 3 μM) and compared its effects to those of AFB1 at 1 μM. Our findings indicated that VerA led to substantial alterations in global gene expression profiles, while AFB1 did not exhibit the same effects. As expected, both toxins caused alterations in gene expression associated with well-known aspects of their toxicity, including mutagenicity, genotoxicity, oxidative stress, and apoptosis. However, we also observed novel features of VerA toxicity, including the ability to cause mitochondrial dysfunction and to trigger a type-1 interferon response, at least partially mediated by cGAS-STING. VerA also induced changes in the expression of genes involved in the regulation of cell shape and adhesion, transcription/translation as well as genes associated with tumor biology. Our results provide new evidence of the high toxicity of VerA and underscore the importance of further assessing the risks associated with its presence in food.

Mitochondrial Function and Dysfunction in White Adipocytes and Therapeutic Implications

For a long time, white adipocytes were thought to function as lipid storages due to the sizeable unilocular lipid droplet that occupies most of their space. However, recent discoveries have highlighted the critical role of white adipocytes in maintaining energy homeostasis and contributing to obesity and related metabolic diseases. These physiological and pathological functions depend heavily on the mitochondria that reside in white adipocytes. This article aims to provide an up-to-date overview of the recent research on the function and dysfunction of white adipocyte mitochondria. After briefly summarizing the fundamental aspects of mitochondrial biology, the article describes the protective role of functional mitochondria in white adipocyte and white adipose tissue health and various roles of dysfunctional mitochondria in unhealthy white adipocytes and obesity. Finally, the article emphasizes the importance of enhancing mitochondrial quantity and quality as a therapeutic avenue to correct mitochondrial dysfunction, promote white adipocyte browning, and ultimately improve obesity and its associated metabolic diseases. © 2024 American Physiological Society. Compr Physiol 14:5581-5640, 2024.

Activation of the Gut-Brain Interaction by Urolithin A and Its Molecular Basis

Background: Urolithin A (Uro-A), a type of polyphenol derived from pomegranate, is known to improve memory function when ingested, in addition to its direct effect on the skin epidermal cells through the activation of longevity gene SIRT1. However, the molI ecular mechanism by which orally ingested Uro-A inhibits cognitive decline via the intestine remains unexplored. Objectives: This study aimed to evaluate the role of Uro-A in improving cognitive function via improved intestinal function and the effect of Uro-A on the inflammation levels and gene expression in hippocampus. Methods: Research to clarify the molecular basis of the functionality of Uro-A was also conducted. Results: The results demonstrated that Uro-A suppressed age-related memory impairment in Aged mice (C57BL/6J Jcl, male, 83 weeks old) by reducing inflammation and altering hippocampal gene expression. Furthermore, exosomes derived from intestinal cells treated with Uro-A and from the serum of Aged mice fed with Uro-A both activated neuronal cells, suggesting that exosomes are promising candidates as mediators of the Uro-A-induced activation of gut-brain interactions. Additionally, neurotrophic factors secreted from intestinal cells may contribute to the Uro-A-induced activation of gut-brain interactions. Conclusions: This study suggests that Uro-A suppresses age-related cognitive decline and that exosomes and other secreted factors may contribute to the activation of the gut-brain interaction. These findings provide new insights into the therapeutic potential of Uro-A for cognitive health.

Unveiling the regulatory role of SIRT1 in the oxidative stress response of bovine mammary cells

High-yield dairy cows typically undergo intense cellular metabolism, leading to oxidative stress in their mammary tissues. Our study found that compared with ordinary cows, these high-yield cows had significantly elevated levels of H2O2, lipoperoxidase, and total antioxidant capacity in their blood. This increased oxidative stress is associated with heightened expression of genes such as GCLC, GCLM, and SIRT1 and proteins such as SIRT1 in the mammary tissue of high-yield cows. We stimulated MAC-T cells with H2O2 at a concentration equal to the average H2O2 level in the serum of ethically high-yielding cows, as detected by an assay kit. Our observations revealed that short-term exposure (12 h) to H2O2 upregulated the expression of the SIRT1 gene and SIRT1 protein. It also increased gene expression for SOD2, CAT, GCLC, GCLM, PGC-1α, and NQO1, elevated the phosphorylation of AMPK, and enhanced protein expression of PGC-1α, NQO1, Nrf2, and HO-1, as well as reduced the phosphorylation of NF-κB. Additionally, short-term H2O2 stimulation resulted in increased total antioxidant capacity and levels of superoxide dismutase, glutathione, and catalase in the mammary epithelial cells of dairy cows. In contrast, prolonged exposure to H2O2 (24 h) yielded opposite results, indicating reduced antioxidant capacity. Further investigation showed that the SIRT1 inhibitor EX 527 could reverse the enhanced cellular antioxidant capacity triggered by short-term oxidative stress. However, it is crucial to note that although 12 h of H2O2 stimulation improved antioxidant capacity, reactive oxygen species (ROS) and malondialdehyde (MDA) levels inside the cell gradually increased over time, suggesting greater damage under long-term stimulation. Conversely, the SIRT1 activator SRT 2104 could reverse the reduced cellular antioxidant capacity caused by long-term oxidative stress and significantly inhibit the accumulation of ROS and MDA. Notably, SRT 2104 demonstrated similar effects in MAC-T cells during lactation. In summary, SIRT1 plays a crucial role in regulating the antioxidant capacity of mammary epithelial cells in dairy cows. This discovery provides valuable insights into the antioxidant mechanisms of mammary cells, which can serve as a theoretical foundation for future mammary health strategies.

The Changes of Mitochondria during Aging and Regeneration

Aging and regeneration are opposite cellular processes. Aging refers to progressive dysfunction in most cells and tissues, and regeneration refers to the replacement of damaged or dysfunctional cells or tissues with existing adult or somatic stem cells. Various studies have shown that aging is accompanied by decreased regenerative abilities, indicating a link between them. The performance of any cellular process needs to be supported by the energy that is majorly produced by mitochondria. Thus, mitochondria may be a link between aging and regeneration. It should be interesting to discuss how mitochondria behave during aging and regeneration. The changes of mitochondria in aging and regeneration discussed in this review can provide a timely and necessary study of the causal roles of mitochondrial homeostasis in longevity and health.

Differences in autophagy marker levels at birth in preterm vs. term infants

BACKGROUND

Preterm infants are susceptible to oxidative stress and prone to respiratory diseases. Autophagy is an important defense mechanism against oxidative-stress-induced cell damage and involved in lung development and respiratory morbidity. We hypothesized that autophagy marker levels differ between preterm and term infants.

METHODS

In the prospective Basel-Bern Infant Lung Development (BILD) birth cohort we compared cord blood levels of macroautophagy (Beclin-1, LC3B), selective autophagy (p62) and regulation of autophagy (SIRT1) in 64 preterm and 453 term infants.

RESULTS

Beclin-1 and LC3B did not differ between preterm and term infants. However, p62 was higher (0.37, 95% confidence interval (CI) 0.05;0.69 in log2-transformed level, p = 0.025, padj = 0.050) and SIRT1 lower in preterm infants (-0.55, 95% CI -0.78;-0.31 in log2-transformed level, padj < 0.001). Furthermore, p62 decreased (padj-value for smoothing function was 0.018) and SIRT1 increased (0.10, 95% CI 0.07;0.13 in log2-transformed level, padj < 0.001) with increasing gestational age.

CONCLUSION

Our findings suggest differential levels of key autophagy markers between preterm and term infants. This adds to the knowledge of the sparsely studied field of autophagy mechanisms in preterm infants and might be linked to impaired oxidative stress response, preterm birth, impaired lung development and higher susceptibility to respiratory morbidity in preterm infants.

IMPACT

To the best of our knowledge, this is the first study to investigate autophagy marker levels between human preterm and term infants in a large population-based sample in cord blood plasma This study demonstrates differential levels of key autophagy markers in preterm compared to term infants and an association with gestational age This may be linked to impaired oxidative stress response or developmental aspects and provide bases for future studies investigating the association with respiratory morbidity.

Effects of intermittent exposure to hypobaric hypoxia and cold on skeletal muscle regeneration: Mitochondrial dynamics, protein oxidation and turnover

Muscle injuries and the subsequent regeneration events compromise muscle homeostasis at morphological, functional and molecular levels. Among the molecular alterations, those derived from the mitochondrial function are especially relevant. We analysed the mitochondrial dynamics, the redox balance, the protein oxidation and the main protein repairing mechanisms after 9 days of injury in the rat gastrocnemius muscle. During the recovery rats were exposed to intermittent cold exposure (ICE), intermittent hypobaric hypoxia (IHH), and both simultaneous combined stimuli. Non-injured contralateral legs were also analysed to evaluate the specific effects of the three environmental exposures. Our results showed that ICE enhanced mitochondrial adaptation by improving the electron transport chain efficiency during muscle recovery, decreased the expression of regulatory subunit of proteasome and accumulated oxidized proteins. Exposure to IHH did not show mitochondrial compensation or increased protein turnover mechanisms; however, no accumulation of oxidized proteins was observed. Both ICE and IHH, when applied separately, elicited an increased expression of eNOS, which could have played an important role in accelerating muscle recovery. The combined effect of ICE and IHH led to a complex response that could potentially impede optimal mitochondrial function and enhanced the accumulation of protein oxidation. These findings underscore the nuanced role of environmental stressors in the muscle healing process and their implications for optimizing recovery strategies.

SIRT-1/RHOT-1/PGC-1α loop modulates mitochondrial biogenesis and transfer to offer resilience following endovascular stem cell therapy in ischemic stroke

Current clinical interventions for stroke majorly involve thrombolysis or thrombectomy, however, cessation of the progressive deleterious cellular cascades post-stroke and long-term neuroprotection are yet to be explored. Mitochondria are highly vulnerable organelles and their dysfunction is one of the detrimental consequences following stroke. Mitochondria dysregulation activate unfavourable cellular events over a period of time that leads to the collapse of neuronal machinery in the brain. Hence, strategies to protect and replenish mitochondria in injured neurons may be useful and needs to be explored. Stem cell therapy in ischemic stroke holds a great promise. Past studies have shown beneficial outcomes of endovascularly delivered stem cells in both pre-clinical and clinical settings. Intra-arterial (IA) administration can provide more cells to the stroke foci and affected brain regions than intravenous administration. Supplying new mitochondria to the stroke-compromised neurons either in the core or penumbra by infused stem cells can help increase their survival and longevity. Previously, our lab has demonstrated that IA 1∗105 mesenchymal stem cells (MSCs) in rats were safe, efficacious and rendered neuroprotection by regulating neuronal calcineurin, modulating sirtuin1(SIRT-1) mediated inflammasome signaling, ameliorating endoplasmic reticulum-stress, alleviation of post-stroke edema and reducing cellular apoptosis. To explore further, our present study aims to investigate the potential of IA MSCs in protecting and replenishing mitochondria in the injured neurons post-stroke and the involvement of SIRT-1/RHOT-1/PGC-1α loop towards mitochondria transfer, biogenesis, and neuroprotection. This study will open new avenues for using stem cells for ischemic stroke in clinics as one of the future adjunctive therapies.

SIRT1-mediated deacetylation of FOXO3 enhances mitophagy and drives hormone resistance in endometrial cancer

BACKGROUND

The complex interplay between Sirtuin 1 (SIRT1) and FOXO3 in endometrial cancer (EC) remains understudied. This research aims to unravel the interactions of deacetylase SIRT1 and transcription factor FOXO3 in EC, focusing on their impact on mitophagy and hormone resistance.

METHODS

High-throughput sequencing, cell experiments, and bioinformatics tools were employed to investigate the roles and interactions of SIRT1 and FOXO3 in EC. Co-immunoprecipitation (Co-IP) assay was used to assess the interaction between SIRT1 and FOXO3 in RL95-2 cells. Functional assays were used to assess cell viability, proliferation, migration, invasion, apoptosis, and the expression of related genes and proteins. A mouse model of EC was established to evaluate tumor growth and hormone resistance under different interventions. Immunohistochemistry and TUNEL assays were used to assess protein expression and apoptosis in tumor tissues.

RESULTS

High-throughput transcriptome sequencing revealed a close association between SIRT1, FOXO3, and EC development. Co-IP showed a protein-protein interaction between SIRT1 and FOXO3. Overexpression of SIRT1 enhanced FOXO3 deacetylation and activity, promoting BNIP3 transcription and PINK1/Parkin-mediated mitophagy, which in turn promoted cell proliferation, migration, invasion, and inhibited apoptosis in vitro, as well as increased tumor growth and hormone resistance in vivo. These findings highlighted SIRT1 as an upstream regulator and potential therapeutic target in EC.

CONCLUSION

This study reveals a novel molecular mechanism underlying the functional relevance of SIRT1 in regulating mitophagy and hormone resistance through the deacetylation of FOXO3 in EC, thereby providing valuable insights for new therapeutic strategies.

MicroRNAs: pioneering regulators in Alzheimer's disease pathogenesis, diagnosis, and therapy

This article delves into Alzheimer's disease (AD), a prevalent neurodegenerative condition primarily affecting the elderly. It is characterized by progressive memory and cognitive impairments, severely disrupting daily life. Recent research highlights the potential involvement of microRNAs in the pathogenesis of AD. MicroRNAs (MiRNAs), short non-coding RNAs comprising 20-24 nucleotides, significantly influence gene regulation by hindering translation or promoting degradation of target genes. This review explores the role of specific miRNAs in AD progression, focusing on their impact on β-amyloid (Aβ) peptide accumulation, intracellular aggregation of hyperphosphorylated tau proteins, mitochondrial dysfunction, neuroinflammation, oxidative stress, and the expression of the APOE4 gene. Our insights contribute to understanding AD's pathology, offering new avenues for identifying diagnostic markers and developing novel therapeutic targets.

Polydatin ameliorates early brain injury after subarachnoid hemorrhage through up-regulating SIRT1 to suppress endoplasmic reticulum stress

Objective

This study aims to investigate the inhibitory effect of Polydatin (PD) on endoplasmic reticulum (ER) stress following subarachnoid hemorrhage (SAH) and to elucidate the underlying mechanisms.

Methods

A standard intravascular puncture model was established to mimic SAH in mice. Neurological functions were assessed using neurological scoring, Grip test, and Morris water maze. Brain edema and Evans blue extravasation were measured to evaluate blood-brain barrier permeability. Western blot and quantitative real-time polymerase chain reaction (PCR) analyses were performed to examine protein and mRNA expressions related to ER stress. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to detect cell apoptosis, and transmission electron microscopy was used to observe the ultrastructure of the endoplasmic reticulum.

Results

The results indicated that PD significantly reduced brain edema and Evans blue extravasation after SAH, improving neurological function. Compared to the SAH group, the expression levels of ER stress-related proteins including glucose-regulated protein 78 (GRP78), phosphorylated protein kinase R-like endoplasmic reticulum kinase (p-PERK), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP), were significantly lower in the PD-treated group. Moreover, PD significantly enhances the protein expression of Sirtuin 1 (SIRT1). Validation with sh-SIRT1 confirmed the critical role of SIRT1 in ER stress, with PD's inhibitory effect on ER stress being dependent on SIRT1 expression. Additionally, PD attenuated ER stress-mediated neuronal apoptosis and SAH-induced ferroptosis through upregulation of SIRT1.

Conclusion

PD alleviates ER stress following SAH by upregulating SIRT1 expression, thereby mitigating early brain injury. The protective effects of PD are mediated through SIRT1, which inhibits ER stress and reduces neuronal apoptosis and ferroptosis.

Polygala fallax Hemsl. ameliorated high glucose-induced podocyte injury by modulating mitochondrial mPTP opening through the SIRT1/PGC-1α pathway

This study aimed to investigate the effects and molecular mechanism of PF on high glucose (HG)-induced podocyte injury. Results found that PF increased proliferation activity, decreased apoptosis, LDH, and caspase-3 levels, and increased nephrin and podocin expression in HG-induced cells. Similarly, PF improved HG-induced mitochondrial damage, decreased Ca2+ and ROS content, alleviated oxidative stress, inhibited mPTP opening, increased mitochondrial membrane potential, and decreased the expressions of Drp1, Bak, Bax, and Cytc in cytoplasm, increased the expressions of SIRT1, PGC-1α, HSP70, HK2, and Cytc in mitochondria of podocytes. The use of mPTP agonist/blocker and SIRT1 inhibitor confirmed that PF alleviates HG-induced podocyte injury by regulating mitochondrial mPTP opening through SIRT1/PGC-1α. In addition, PF affected HK2-VDAC1 protein binding to regulate mPTP opening via the SIRT1/PGC-1α pathway. In conclusion, PF-regulated HK2-VDAC1 protein binding affected mitochondrial mPTP opening and improved HG-induced podocyte injury through the SIRT1/PGC-1α pathway.

Ropivacaine prompts ferroptosis to enhance the cisplatin-sensitivity of human colorectal cancer through SIRT1/Nrf2 signaling pathway

The ineffectiveness of cisplatin therapy in treating colorectal cancer (CRC) is attributed to an increase of resistance. It's necessary to investigate adjunctive agents capable of enhancing drug efficacy. Previous studies have shown that ropivacaine inhibit the growth of various cancer cells, but its impact on cisplatin resistance in tumors is not well understood. This study was to illustrate the impact and mechanism of ropivacaine enhanced cisplatin-sensitivity of CRC. Cisplatin alone treatment resulted in the elevation of reactive oxygen species (ROS) and intracellular Fe2+ levels, as well as a reduction in mitochondrial membrane potential (MMP) in cisplatin-sensitive LOVO cells, while these effects were mitigated in the cisplatin-resistant LOVO/DDP cells. The co-administration of ropivacaine with cisplatin inhibited cell viability and cell migration, decreased MMP, and promoted ROS accumulation and apoptosis in both LOVO cells and LOVO/DDP cells. And they upregulated the levels of ferroptosis makers and downregulated the expression of anti-ferroptosis proteins. However, this effect was reversed by ferroptosis inhibitor ferrostatin-1 or liproxstatin-1. Furthermore, we o demonstrated that the co-administration of ropivacaine and cisplatin resulted in a decrease in SIRT1 expression, and SIRT1 knockdown in LOVO/DDP cells enhanced the ferroptosis and the anti-tumor properties of ropivacaine, while also inhibiting the activation of the Nrf2/Keap1 pathway. The above results suggested that ropivacaine increased the sensitivity of CRC cells to cisplatin by promoting ferroptosis through the inhibition of SIRT1 expression, which proposes a therapeutic approach for overcoming cisplatin resistance in CRC.

LncRNAs are involved in regulating ageing and age-related disease through the adenosine monophosphate-activated protein kinase signalling pathway

A long noncoding RNA (lncRNA) is longer than 200 bp. It regulates various biological processes mainly by interacting with DNA, RNA, or protein in multiple kinds of biological processes. Adenosine monophosphate-activated protein kinase (AMPK) is activated during nutrient starvation, especially glucose starvation and oxygen deficiency (hypoxia), and exposure to toxins that inhibit mitochondrial respiratory chain complex function. AMPK is an energy switch in organisms that controls cell growth and multiple cellular processes, including lipid and glucose metabolism, thereby maintaining intracellular energy homeostasis by activating catabolism and inhibiting anabolism. The AMPK signalling pathway consists of AMPK and its upstream and downstream targets. AMPK upstream targets include proteins such as the transforming growth factor β-activated kinase 1 (TAK1), liver kinase B1 (LKB1), and calcium/calmodulin-dependent protein kinase β (CaMKKβ), and its downstream targets include proteins such as the mechanistic/mammalian target of rapamycin (mTOR) complex 1 (mTORC1), hepatocyte nuclear factor 4α (HNF4α), and silencing information regulatory 1 (SIRT1). In general, proteins function relatively independently and cooperate. In this article, a review of the currently known lncRNAs involved in the AMPK signalling pathway is presented and insights into the regulatory mechanisms involved in human ageing and age-related diseases are provided.

Biological functions and biomedical applications of extracellular vesicles derived from blood cells

There is a growing interest in using extracellular vesicles (EVs) for therapeutic applications. EVs are composed of cytoplasmic proteins and nucleic acids and an external lipid bilayer containing transmembrane proteins on their surfaces. EVs can alter the state of the target cells by interacting with the receptor ligand of the target cell or by being internalised by the target cell. Blood cells are the primary source of EVs, and 1 μL of plasma contains approximately 1.5 × 107 EVs. Owing to their easy acquisition and the avoidance of cell amplification in vitro, using blood cells as a source of therapeutic EVs has promising clinical application prospects. This review summarises the characteristics and biological functions of EVs derived from different blood cell types (platelets, erythrocytes, and leukocytes) and analyses the prospects and challenges of using them for clinical therapeutic applications. In summary, blood cell-derived EVs can regulate different cell types such as immune cells (macrophages, T cells, and dendritic cells), stem cells, and somatic cells, and play a role in intercellular communication, immune regulation, and cell proliferation. Overall, blood cell-derived EVs have the potential for use in vascular diseases, inflammatory diseases, degenerative diseases, and injuries. To promote the clinical translation of blood cell-derived EVs, researchers need to perform further studies on EVs in terms of scalable and reproducible isolation technology, quality control, safety, stability and storage, regulatory issues, cost-effectiveness, and long-term efficacy.

Mitochondrial DNA transcription and mitochondrial genome-encoded long noncoding RNA in diabetic retinopathy

In diabetic retinopathy, mitochondrial DNA (mtDNA) is damaged and mtDNA-encoded genes and long noncoding RNA cytochrome B (LncCytB) are downregulated. LncRNAs lack an open reading frame, but they can regulate gene expression by associating with DNA/RNA/protein. Double stranded mtDNA has promoters on both heavy (HSP) and light (LSP) strands with binding sites for mitochondrial transcription factor A (TFAM) between them. The aim was to investigate the role of LncCytB in mtDNA transcription in diabetic retinopathy. Using human retinal endothelial cells incubated in high glucose, the effect of regulation of LncCytB on TFAM binding at mtDNA promoters was investigated by Chromatin immunoprecipitation, and binding of LncCytB at TFAM by RNA immunoprecipitation and RNA fluorescence in situ hybridization. High glucose decreased TFAM binding at both HSP and LSP, and binding of LncCytB at TFAM. While LncCytB overexpression ameliorated decrease in TFAM binding and transcription of genes encoded by both H- and L- strands, LncCytB-siRNA further downregulated them. Maintenance of mitochondrial homeostasis by overexpressing mitochondrial superoxide dismutase or Sirtuin-1 protected diabetes-induced decrease in TFAM binding at mtDNA and LncCytB binding at TFAM, and mtDNA transcription. Similar results were obtained from mouse retinal microvessels from streptozotocin-induced diabetic mice. Thus, LncCytB facilitates recruitment of TFAM at HSP and LSP, and its downregulation in diabetes compromises the binding, resulting in the downregulation of polypeptides encoded by mtDNA. Regulation of LncCytB, in addition to protecting mitochondrial genomic stability, should also help in maintaining the transcription of mtDNA encoded genes and electron transport chain integrity in diabetic retinopathy.

Temporal expression of mitochondrial life cycle markers during acute and chronic overload of rat plantaris muscles

Skeletal muscle hypertrophy is generally associated with a fast-to-slow phenotypic adaptation in both human and rodent models. Paradoxically, this phenotypic shift is not paralleled by a concomitant increase in mitochondrial content and aerobic markers that would be expected to accompany a slow muscle phenotype. To understand the temporal response of the mitochondrial life cycle (i.e., biogenesis, oxidative phosphorylation, fission/fusion, and mitophagy/autophagy) to hypertrophic stimuli, in this study, we used the functional overload (FO) model in adult female rats and examined the plantaris muscle responses at 1 and 10 weeks. As expected, the absolute plantaris muscle mass increased by ∼12 and 26% at 1 and 10 weeks following the FO procedure, respectively. Myosin heavy-chain isoform types I and IIa significantly increased by 116% and 17%, respectively, in 10-week FO plantaris muscles. Although there was a general increase in protein markers associated with mitochondrial biogenesis in acute FO muscles, this response was unexpectedly sustained under 10-week FO conditions after muscle hypertrophy begins to plateau. Furthermore, the early increase in mito/autophagy markers observed under acute FO conditions was normalized by 10 weeks, suggesting a cellular environment favoring mitochondrial biogenesis to accommodate the aerobic demands of the plantaris muscle. We also observed a significant increase in the expression of mitochondrial-, but not nuclear-, encoded oxidative phosphorylation (OXPHOS) proteins and peptides (i.e., humanin and MOTS-c) under chronic, but not acute, FO conditions. Taken together, the temporal response of markers related to the mitochondrial life cycle indicates a pattern of promoting biogenesis and mitochondrial protein expression to support the energy demands and/or enhanced neural recruitment of chronically overloaded skeletal muscle.

Inter-organ differences in redox imbalance and apoptosis depict metabolic resilience in migratory redheaded buntings

Migration, a bird's metabolic apex, depends primarily on the liver and muscle for fuel mobilization and endurance flight. In migratory redheaded buntings, adaptive increase in mitochondrial membrane (MM) proton gradient to drive ATP synthesis, measured by MM potential (MMP+) and reactive oxygen species (ROS) response, have been well characterized in the blood but not in the muscle or liver. We assessed MMP+, ROS, and apoptosis in the liver and pectoralis muscle of photosensitive nonmigratory (nMig.) male redheaded buntings photoinduced to migratory (Mig.) states. Relative expression levels of genes associated with energy (ACADM, PEPCK, GOT2, GLUT1, and CS), ROS modulation (SIRT1), mitochondrial free-radical scavengers (SOD1, PRX4, NOS2, GPX1, and GPX4), anti-apoptotic genes (NF-κβ), apoptotic (CASP7), and tissue damage using histology, during migration were assessed. The MMP+ decreased and the ROS concentration increased, due to the metabolic load on liver and pectoralis muscle tissues during Mig. However, percentage of apoptotic cells increased in liver but decreased in muscle, which is of functional significance to migratory passerines. During Mig., in muscle, SIRT1 increased, while an increase in anti-apoptotic NF-κβ aided immune pathway-mediated antioxidant activity and guarded against muscle oxidative damage during migration. Inter-organ differences in metabolism add to our current understanding of metabolic flexibility that supports successful migration in buntings.

Enhancing catechins, antioxidant and sirtuin 1 enzyme stimulation activities in green tea extract through pulse electric field-assisted water extraction: Optimization by response surface methodology approach

Green tea is an economic resource in Thailand because it is derived from smallholder agriculture and has expanded into food production. The purpose of this study is to optimize the parameters of pulsed electric field (PEF) assisted green tea extraction to produce a natural health product. A central composite design was involved to determine the effect of independent variables, including the intensity of electric field (I; 3-5 kV/cm), number of pulses (Np; 1000 to 3000 pulses) and green tea-to-water ratio (GT/W; 0.05-0.15 g/mL) on catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG), total phenolic compound, antioxidant and sirtuin 1 enzyme stimulating activities. The results indicated that the Np had the most significant impact (p < 0.05) on the content of catechin and its derivatives and sirtuin 1 enzyme stimulating activity. The observations revealed that the I had a greater impact on antioxidant activities compared to the Np. The optimal conditions for PEF using the response surface method were determined to be I of 5 kV/cm, Np of 3000 pulses, GT/W of 0.14 g/mL and specific energy of 27 kJ/kg. Under the optimized conditions, the content of C, EC, ECG, EGC and EGCG were 7.34 ± 0.33, 11.26 ± 0.25, 3.75 ± 0.13, 7.53 ± 0.77 and 37.78 ± 0.58 mg/g extract, respectively. Furthermore, it was observed that green tea extract exhibited the ability to modulate the deacetylation activity of the sirtuin 1 enzyme, with a value of 22.63 ± 0.17 FIR. The results emphasized that the PEF led to achieving better responses compared to without pre-treatment using the PEF. Therefore, innovative technologies as PEF can be utilized for green tea extraction to produce natural ingredients, which can contribute to improved accessibility to healthcare. Additionally, the implementation of innovation techniques, such as PEF, in the extraction industry can enhance productivity growth and economic development.

Oxidative stress and senescence in aging kidneys: the protective role of SIRT1

Aging leads to a gradual decline in kidney function, making the kidneys increasingly vulnerable to various diseases. Oxidative stress, together with cellular senescence, has been established as paramount in promoting the aging process of the kidney. Oxidative stress, defined as an imbalance between ROS formation and antioxidant defense mechanisms, has been implicated in the kidney's cellular injury, inflammation, and premature senescence. Concurrently, the accumulation of SCs in the kidney also exacerbates oxidative stress via the secretion of pro-inflammatory and tissue-damaging factors as the senescence-associated secretory phenotype (SASP). Recently, SIRT1, a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, has been pivotal in combating oxidative stress and cellular senescence in the aging kidney. SIRT1 acts as a potential antioxidant molecule through myriad pathways that influence diverse transcription factors and enzymes essential in maintaining redox homeostasis. SIRT1 promotes longevity and renal health by modulating the acetylation of cell cycle and senescence pathways. This review covers the complex relationship between oxidative stress and cellular senescence in the aging kidney, emphasizing the protective role of SIRT1. See also the graphical abstract(Fig. 1).

Allosteric Activation of SIRT1 by 2,4-Dihydroxy-azaflavanone Averts MPP+-Mediated Dysfunction in Mitochondrial Biogenesis and Bioenergetics: Implications for Parkinson's Disease

Parkinson's disease (PD) is a complex neurodegenerative disorder that affects dopamine neurons of the substantia nigra pars compacta (SNpc), resulting in motor dysfunction. Among the pathways examined, mitochondria and α-synuclein were found to play a major role in the disease progression. Hence, several attempts are being made to restore mitochondrial bioenergetics or protein aggregation pathways as disease-modifying strategies. Our earlier studies reported the protective effect of 2,4-dihydroxy-azaflavanone (azaflavanone) in a transgenic Drosophila fly model of PD. In the present study, we found that azaflavanone acts as an allosteric activator of SIRT1 in both cell-free and cell-based systems and the effects were more pronounced as compared to resveratrol. Also, azaflavanone appears to interact selectively with SIRT1 as other SIRTs such as SIRT3 and SIRT6 did not exhibit any gross changes in cellular thermal shift assay (CETSA). Molecular docking studies depicted a higher docking score with azaflavanone than with resveratrol. Further, N27 cells treated with azaflavanone exhibited a dose-dependent increase in the mitotracker staining, mtDNA/nuclear DNA ratio, and also mitochondrial bioenergetics. The observed effects appear to be due to the activation of SIRT1, as evidenced by an increase in the expression of PGC-1α and TFAM, which are the downstream targets of SIRT1. Lastly, the Parkinsonian mimic MPP+-induced disturbance in the mitochondrial membrane potential, mitochondrial bioenergetics, and biogenesis were ameliorated by azaflavanone. Overall, our findings indicate that azaflavanone, being an antioxidant and an allosteric activator of SIRT1, is a promising compound for ameliorating the pathophysiology of PD.

Crosstalk between the DNA damage response and cellular senescence drives aging and age-related diseases

Cellular senescence is a crucial process of irreversible cell-cycle arrest, in which cells remain alive, but permanently unable to proliferate in response to distinct types of stressors. Accumulating evidence suggests that DNA damage builds over time and triggers DNA damage response signaling, leading to cellular senescence. Cellular senescence serves as a platform for the perpetuation of inflammatory responses and is central to numerous age-related diseases. Defects in DNA repair genes or senescence can cause premature aging disease. Therapeutic approaches limiting DNA damage or senescence contribute to a rescued phenotype of longevity and neuroprotection, thus suggesting a mechanistic interaction between DNA damage and senescence. Here, we offer a unique perspective on the crosstalk between the DNA damage response pathway and senescence as well as their contribution to age-related diseases. We further summarize recent progress on the mechanisms and therapeutics of senescence, address existing challenges, and offering new insights and future directions in the senescence field.

Gut microbiota as a sensor of autoimmune response and treatment for rheumatoid arthritis

Rheumatoid arthritis (RA) is considered a multifactorial condition where interaction between the genetic and environmental factors lead to immune dysregulation causing autoreactivity. While among the various genetic factors, HLA-DR4 and DQ8, have been reported to be the strongest risk factors, the role of various environmental factors has been unclear. Though events initiating autoreactivity remain unknown, a mucosal origin of RA has gained attention based on the recent observations with the gut dysbiosis in patients. However, causality of gut dysbiosis has been difficult to prove in humans. Mouse models, especially mice expressing RA-susceptible and -resistant HLA class II genes have helped unravel the complex interactions between genetic factors and gut microbiome. This review describes the interactions between HLA genes and gut dysbiosis in sex-biased preclinical autoreactivity and discusses the potential use of endogenous commensals as indicators of treatment efficacy as well as therapeutic tool to suppress pro-inflammatory response in rheumatoid arthritis.

Histone deacetylases and inhibitors in diabetes mellitus and its complications

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, with its prevalence linked to both genetic predisposition and environmental factors. Epigenetic modifications, particularly through histone deacetylases (HDACs), have been recognized for their significant influence on DM pathogenesis. This review focuses on the classification of HDACs, their role in DM and its complications, and the potential therapeutic applications of HDAC inhibitors. HDACs, which modulate gene expression without altering DNA sequences, are categorized into four classes with distinct functions and tissue specificity. HDAC inhibitors (HDACi) have shown efficacy in various diseases, including DM, by targeting these enzymes. The review highlights how HDACs regulate β-cell function, insulin sensitivity, and hepatic gluconeogenesis in DM, as well as their impact on diabetic cardiomyopathy, nephropathy, and retinopathy. Finally, we suggest that targeted histone modification is expected to become a key method for the treatment of diabetes and its complications. The study of HDACi offers insights into new treatment strategies for DM and its associated complications.

SIRT-associated attenuation of cellular senescence in vascular wall

This review focuses on the vital function that SIRT1 and other sirtuins play in promoting cellular senescence in vascular smooth muscle cells, which is a key element in the pathogenesis of vascular aging and associated cardiovascular diseases. Vascular aging is a gradual process caused by the accumulation of senescent cells, which results in increased vascular remodeling, stiffness, and diminished angiogenic ability. Such physiological alterations are characterized by a complex interplay of environmental and genetic variables, including oxidative stress and telomere attrition, which affect gene expression patterns and trigger cell growth arrest. SIRT1 has been highlighted for its potential to reduce cellular senescence through modulation of multiple signaling cascades, particularly the endothelial nitric oxide (eNOS)/NO signaling pathway. It also modulates cell cycle through p53 inactivation and suppresses NF-κB mediated expression of adhesive molecules at the vascular level. The study also examines the therapeutic potential of sirtuin modulation in vascular health, identifying SIRT1 and its sirtuin counterparts as potential targets for reducing vascular aging. This study sheds light on the molecular basis of vascular aging and the beneficial effects of sirtuins, paving the way for the development of tailored therapies aimed at enhancing vascular health and prolonging life.

Dapagliflozin improves skeletal muscle insulin sensitivity through SIRT1 activation induced by nutrient deprivation state

Lipid peroxidation and mitochondrial damage impair insulin sensitivity in skeletal muscle. Sirtuin-1 (SIRT1) protects mitochondria and activates under energy restriction. Dapagliflozin (Dapa) is an antihyperglycaemic agent that belongs to the sodium-glucose cotransporter-2 (SGLT2) inhibitors. Evidence shows that Dapa can induce nutrient deprivation effects, providing additional metabolic benefits. This study investigates whether Dapa can trigger nutrient deprivation to activate SIRT1 and enhance insulin sensitivity in skeletal muscle. We treated diet-induced obese (DIO) mice with Dapa and measured metabolic parameters, lipid accumulation, oxidative stress, mitochondrial function, and glucose utilization in skeletal muscle. β-hydroxybutyric acid (β-HB) was intervened in C2C12 myotubes. The role of SIRT1 was verified by RNA interference. We found that Dapa treatment induced nutrient deprivation state and reduced lipid deposition and oxidative stress, improved mitochondrial function and glucose tolerance in skeletal muscle. The same positive effects were observed after β-HB intervening for C2C12 myotubes, and the promoting effects on glucose utilization were diminished by SIRT1 RNA interference. Thus, Dapa promotes a nutrient deprivation state and enhances skeletal muscle insulin sensitivity via SIRT1 activation. In this study, we identified a novel hypoglycemic mechanism of Dapa and the potential mechanistic targets.

Daily Vinegar Ingestion Improves Depression and Enhances Niacin Metabolism in Overweight Adults: A Randomized Controlled Trial

Depressive disorders are the most prevalent mental health conditions in the world. The commonly prescribed antidepressant medications can have serious side effects, and their efficacy varies widely. Thus, simple, effective adjunct therapies are needed. Vinegar, a fermented acetic acid solution, is emerging as a healthful dietary supplement linked to favorable outcomes for blood glucose management, heart disease risk, and adiposity reduction, and a recent report suggests vinegar may improve symptoms of depression. This randomized controlled study examined the 4-week change in scores for the Center for Epidemiological Studies Depression (CES-D) questionnaire and the Patient Health Questionnaire (PHQ-9) in healthy overweight adults ingesting 2.95 g acetic acid (4 tablespoons vinegar) vs. 0.025 g acetic acid (one vinegar pill) daily. A secondary objective explored possible underlying mechanisms using metabolomics analyses. At week 4, mean CES-D scores fell 26% and 5% for VIN and CON participants respectively, a non-significant difference between groups, and mean PHQ-9 scores fell 42% and 18% for VIN and CON participants (p = 0.036). Metabolomics analyses revealed increased nicotinamide concentrations and upregulation of the NAD+ salvage pathway for VIN participants compared to controls, metabolic alterations previously linked to improved mood. Thus, daily vinegar ingestion over four weeks improved self-reported depression symptomology in healthy overweight adults, and enhancements in niacin metabolism may factor into this improvement.

Therapeutic Potential of Quercetin as an Antioxidant for Bone-Muscle-Tendon Regeneration and Aging

Quercetin (QC), a naturally occurring bioflavonoid found in various fruits and vegetables, possesses many potential health benefits, primarily attributed to its robust antioxidant properties. The generation of oxidative stress in bone cells is a key modulator of their physiological behavior. Moreover, oxidative stress status influences the pathophysiology of mineralized tissues. Increasing scientific evidence demonstrates that manipulating the redox balance in bone cells might be an effective technique for developing bone disease therapies. The QC antioxidant abilities in skeletal muscle significantly enhance muscle regeneration and reduce muscle atrophy. In addition, QC has been shown to have protective effects against oxidative stress, inflammation, apoptosis, and matrix degradation in tendons, helping to maintain the structural integrity and functionality of tendons. Thus, the antioxidant properties of QC might be crucial for addressing age-related musculoskeletal disorders like osteoporosis, sarcopenia, and tendon-related inflammatory conditions. Understanding how QC influences redox signaling pathways involved in musculoskeletal disorders, including their effect on bone, muscle, and tendon differentiation, might provide insights into the diverse advantages of QC in promoting tissue regeneration and preventing cellular damage. Therefore, this study reviewed the intricate relationship among oxidative stress, inflammation, and tissue repair, affected by the antioxidative abilities of QC, in age-related musculoskeletal tissues to improve the overall health of bones, muscles, and tendons of the skeletal system. Also, reviewing the ongoing clinical trials of QC for musculoskeletal systems is encouraging. Given the positive effect of QC on musculoskeletal health, further scientific investigations and controlled human intervention studies are necessary to explore the therapeutic potential to its optimum strength.

Dulaglutide restores endothelial progenitor cell levels in diabetic mice and mitigates high glucose-induced endothelial injury through SIRT1-mediated mitochondrial fission

Type 2 diabetes mellitus (T2DM) significantly impairs the functionality and number of endothelial progenitor cells (EPCs) and resident endothelial cells, critical for vascular repair and regeneration, exacerbating the risk of vascular complications. GLP-1 receptor agonists, like dulaglutide, have emerged as promising therapeutic agents due to their multifaceted effects, including the enhancement of EPC activity and protection of endothelial cells. This study investigates dulaglutide's effects on peripheral blood levels of CD34+ and CD133+ cells in a mouse model of lower limb ischemia and its protective mechanisms against high-glucose-induced damage in endothelial cells. Results demonstrated that dulaglutide significantly improves blood flow, reduces tissue damage and inflammation in ischemic limbs, and enhances glycemic control. Furthermore, dulaglutide alleviated high-glucose-induced endothelial cell damage, evident from improved tube formation, reduced reactive oxygen species accumulation, and restored endothelial junction integrity. Mechanistically, dulaglutide mitigated mitochondrial fission in endothelial cells under high-glucose conditions, partly through maintaining SIRT1 expression, which is crucial for mitochondrial dynamics. This study reveals the potential of dulaglutide as a therapeutic option for vascular complications in T2DM patients, highlighting its role in improving endothelial function and mitochondrial integrity.

Peripheral inflammation as a potential mechanism and preventive strategy for perioperative neurocognitive disorder under general anesthesia and surgery

General anesthesia, as a commonly used medical intervention, has been widely applied during surgical procedures to ensure rapid loss of consciousness and pain relief for patients. However, recent research suggests that general anesthesia may be associated with the occurrence of perioperative neurocognitive disorder (PND). PND is characterized by a decline in cognitive function after surgery, including impairments in attention, memory, learning, and executive functions. With the increasing trend of population aging, the burden of PND on patients and society's health and economy is becoming more evident. Currently, the clinical consensus tends to believe that peripheral inflammation is involved in the pathogenesis of PND, providing strong support for further investigating the mechanisms and prevention of PND.

Mitochondrial Morphology and Function Abnormality in Ovarian Granulosa Cells of Patients with Diminished Ovarian Reserve

In this study, we examined the changes in the mitochondrial structure and function in cumulus granulosa cells of patients with diminished ovarian reserve (DOR) to explore the causes and mechanisms of decreased mitochondrial quality. The mitochondrial ultrastructure was observed by transmission electron microscope, and the function was determined by detecting the ATP content, reactive oxygen species (ROS) levels, the number of mitochondria, and the mitochondrial membrane potential. The expression of ATP synthases in relation to mitochondrial function was analyzed. Additionally, protein immunoblotting was used to compare the expression levels of mitochondrial kinetic protein, the related channel protein in the two groups. Patients with DOR had abnormal granulosa cell morphology, increased mitochondrial abnormalities, decreased mitochondrial function, and disturbed mitochondrial dynamics. Additionally, the silent information regulator 1 (SIRT1)/phospho-AMP-activated protein kinase (P-AMPK)-peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) pathway expression was decreased, which was speculated to be associated with the decreased mitochondrial mass in the DOR group. The mitochondrial mass was decreased in granulosa cells of patients in the DOR group. The mitochondrial dysfunction observed in granulosa cells of patients in the DOR group may be associated with dysregulation of the SIRT1/P-AMPK-PGC-1α-mitochondrial transcription factor A (TFAM) pathway.

Emerging phosphodiesterase inhibitors for treatment of neurodegenerative diseases

Neurodegenerative diseases (NDs) cause progressive loss of neuron structure and ultimately lead to neuronal cell death. Since the available drugs show only limited symptomatic relief, NDs are currently considered as incurable. This review will illustrate the principal roles of the signaling systems of cyclic adenosine and guanosine 3',5'-monophosphates (cAMP and cGMP) in the neuronal functions, and summarize expression/activity changes of the associated enzymes in the ND patients, including cyclases, protein kinases, and phosphodiesterases (PDEs). As the sole enzymes hydrolyzing cAMP and cGMP, PDEs are logical targets for modification of neurodegeneration. We will focus on PDE inhibitors and their potentials as disease-modifying therapeutics for the treatment of Alzheimer's disease, Parkinson's disease, and Huntington's disease. For the overlapped but distinct contributions of cAMP and cGMP to NDs, we hypothesize that dual PDE inhibitors, which simultaneously regulate both cAMP and cGMP signaling pathways, may have complementary and synergistic effects on modifying neurodegeneration and thus represent a new direction on the discovery of ND drugs.

Tissue-resident C1q + macrophages exert anti-aging potential through the Sirt1 pathway

OBJECTIVE

Resident immune cells are at the forefront of sensory organ-specific signals, and changes in these cells are closely related to the aging process. The Sirt pathway can regulate NAD + metabolism during aging, thereby affecting the accumulation of ROS. However, the role of the Sirt pathway in resident immune cells in aged tissues is currently unclear.

METHODS

We investigated Sirt1 signalling in resident immune cells during chronic inflammation in an aged mouse model. Integrated single-cell RNA sequencing data from young and aged mice were used to refine the characterization of immune cells in aged tissues RESULTS: We found that C1q + macrophages could affect chronic inflammation during aging. C1q + macrophages acted in an opposing manner to Il1b + macrophages and were responsible for anti-inflammatory effects during aging. Sirt1 agonists inhibited the decrease in C1qb in macrophages during aging, and anti-aging drugs could affect the expression of C1qb in macrophages via the Sirt1 pathway.

CONCLUSIONS

In this study, we first identified the relevance of C1q + macrophages in chronic inflammation during aging. The potential anti-aging effect of C1q + macrophages was mediated by the Sirt1 pathway, suggesting new strategies for aging immunotherapy.

Role of the gut-muscle axis in mitochondrial function of ageing muscle under different exercise modes

The fundamental role of the gut microbiota through the gut-muscle axis in skeletal muscle ageing is increasingly recognised. Metabolites derived from the intestinal microbiota are essential in maintaining skeletal muscle function and metabolism. The energy produced by mitochondria and moderate levels of reactive oxygen species can contribute to this process. Metabolites can effectively target the mitochondria, slowing the progression of muscle ageing and potentially representing a marker of ageing-related skeletal muscle loss. Moreover, mitochondria can contribute to the immune response, gut microbiota biodiversity, and maintenance of the intestinal barrier function. However, the causal relationship between mitochondrial function and gut microbiota crosstalk remains poorly understood. In addition to elucidating the regulatory pathways of the gut-muscle axis during the ageing process, we focused on the potential role of the "exercise-gut-muscle axis", which represents a pathway under stimulation from different exercise modes to induce mitochondrial adaptations, skeletal muscle metabolism and maintain intestinal barrier function and biodiversity stability. Meanwhile, different exercise modes can induce mitochondrial adaptations and skeletal muscle metabolism and maintain intestinal barrier function and biodiversity. Resistance exercise may promote mitochondrial adaptation, increase the cross-sectional area of skeletal muscle and muscle hypertrophy, and promote muscle fibre and motor unit recruitment. Whereas endurance exercise promotes mitochondrial biogenesis, aerobic capacity, and energy utilisation, activating oxidative metabolism-related pathways to improve skeletal muscle metabolism and function. This review describes the effects of different exercise modes through the gut-muscle axis and how they act through mitochondria in ageing to define the current state of the field and issues requiring resolution.

Sirt1 Deficiency Promotes Age-Related AF Through Enhancing Atrial Necroptosis by Activation of RIPK1 Acetylation

BACKGROUND

Aging is one of the most potent risk determinants for the onset of atrial fibrillation (AF). Sirts (sirtuins) have been implicated in the pathogenesis of cardiovascular disease, and their expression declines with aging. However, whether Sirts involved in age-related AF and its underlying mechanisms remain unknown. The present study aims to explore the role of Sirts in age-related AF and delineate the underlying molecular mechanisms.

METHODS

Sirt1 levels in the atria of both elderly individuals and aging rats were evaluated using quantitative real-time polymerase chain reaction and Western blot analysis. Mice were engineered to specifically knockout Sirt1 in the atria and right ventricle (Sirt1mef2c/mef2c). Various techniques, such as echocardiography, atrial electrophysiology, and protein acetylation modification omics were employed. Additionally, coimmunoprecipitation was utilized to substantiate the interaction between Sirt1 and RIPK1 (receptor-interacting protein kinase 1).

RESULTS

We discerned that among the diverse subtypes of sirtuin proteins, only Sirt1 expression was significantly diminished in the atria of elderly people and aged rats. The Sirt1mef2c/mef2c mice exhibited an enlarged atrial diameter and heightened vulnerability to AF. Acetylated proteomics and cell experiments identified that Sirt1 deficiency activated atrial necroptosis through increasing RIPK1 acetylation and subsequent pseudokinase MLKL (mixed lineage kinase domain-like protein) phosphorylation. Consistently, necroptotic inhibitor necrosulfonamide mitigated atrial necroptosis and diminished both the atrial diameter and AF susceptibility of Sirt1mef2c/mef2c mice. Resveratrol prevented age-related AF in rats by activating atrial Sirt1 and inhibiting necroptosis.

CONCLUSIONS

Our findings first demonstrated that Sirt1 exerts significant efficacy in countering age-related AF by impeding atrial necroptosis through regulation of RIPK1 acetylation, highlighting that the activation of Sirt1 or the inhibition of necroptosis could potentially serve as a therapeutic strategy for age-related AF.

Menaquinone-4 alleviates hypoxic-ischemic brain damage in neonatal rats by reducing mitochondrial dysfunction via Sirt1-PGC-1α-TFAM signaling pathway

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is a major contributor to neonatal mortality and neurodevelopmental disorders, but currently there is no effective therapy drug for HIE. Mitochondrial dysfunction plays a pivotal role in hypoxic-ischemic brain damage(HIBD). Menaquinone-4 (MK-4), a subtype of vitamin K2 prevalent in the brain, has been shown to enhance mitochondrial function and exhibit protective effects against ischemia-reperfusion injury. However, the impact and underlying molecular mechanism of MK-4 in HIE have not been fully elucidated.

METHODS

In this study, we established the neonatal rats HIBD model in vivo and oxygen-glucose deprivation and reperfusion (OGD/R) of primary neurons in vitro to explore the neuroprotective effects of MK-4 on HI damage, and illuminate the potential mechanism.

RESULTS

Our findings revealed that MK-4 ameliorated mitochondrial dysfunction, reduced oxidative stress, and prevented HI-induced neuronal apoptosis by activating the Sirt1-PGC-1α-TFAM signaling pathway through Sirt1 mediation. Importantly, these protective effects were partially reversed by EX-527, a Sirt1 inhibitor.

CONCLUSION

Our study elucidated the potential therapeutic mechanism of MK-4 in neonatal HIE, suggesting its viability as an agent for enhancing recovery from HI-induced cerebral damage in newborns. Further exploration into MK-4 could lead to novel interventions for HIE therapy.

Arctigenin derivative A-1 ameliorates motor dysfunction and pathological manifestations in SOD1G93A transgenic mice via the AMPK/SIRT1/PGC-1α and AMPK/SIRT1/IL-1β/NF-κB pathways

AIM

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease characterized by progressive death of upper and lower motor neurons, leading to generalized muscle atrophy, paralysis, and even death. Mitochondrial damage and neuroinflammation play key roles in the pathogenesis of ALS. In the present study, the efficacy of A-1, a derivative of arctigenin with AMP-activated protein kinase (AMPK) and silent information regulator 1 (SIRT1) activation for ALS, was investigated.

METHODS

A-1 at 33.3 mg/kg was administrated in SOD1G93A transgenic mice orally from the 13th week for a 6-week treatment period. Motor ability was assessed before terminal anesthesia. Muscle atrophy and fibrosis, motor neurons, astrocytes, and microglia in the spinal cord were evaluated by H&E, Masson, Sirius Red, Nissl, and immunohistochemistry staining. Protein expression was detected with proteomics analysis, Western blotting, and ELISA. Mitochondrial adenosine triphosphate (ATP) and malondialdehyde (MDA) levels were measured using an assay kit.

RESULTS

A-1 administration in SOD1G93A mice enhanced mobility, decreased skeletal muscle atrophy and fibrosis, mitigated loss of spinal motor neurons, and reduced glial activation. Additionally, A-1 treatment improved mitochondrial function, evidenced by elevated ATP levels and increased expression of key mitochondrial-related proteins. The A-1 treatment group showed decreased levels of IL-1β, pIκBα/IκBα, and pNF-κB/NF-κB.

CONCLUSIONS

A-1 treatment reduced motor neuron loss, improved gastrocnemius atrophy, and delayed ALS progression through the AMPK/SIRT1/PGC-1α pathway, which promotes mitochondrial biogenesis. Furthermore, the AMPK/SIRT1/IL-1β/NF-κB pathway exerted neuroprotective effects by reducing neuroinflammation. These findings suggest A-1 as a promising therapeutic approach for ALS.

Cardioprotective properties of OMT-28, a synthetic analog of omega-3 epoxyeicosanoids

OMT-28 is a metabolically robust small molecule developed to mimic the structure and function of omega-3 epoxyeicosanoids. However, it remained unknown to what extent OMT-28 also shares the cardioprotective and anti-inflammatory properties of its natural counterparts. To address this question, we analyzed the ability of OMT-28 to ameliorate hypoxia/reoxygenation (HR)-injury and lipopolysaccharide (LPS)-induced endotoxemia in cultured cardiomyocytes. Moreover, we investigated the potential of OMT-28 to limit functional damage and inflammasome activation in isolated perfused mouse hearts subjected to ischemia/reperfusion (IR) injury. In the HR model, OMT-28 (1 μM) treatment largely preserved cell viability (about 75 versus 40% with the vehicle) and mitochondrial function as indicated by the maintenance of NAD+/NADH-, ADP/ATP-, and respiratory control ratios. Moreover, OMT-28 blocked the HR-induced production of mitochondrial reactive oxygen species. Pharmacological inhibition experiments suggested that Gαi, PI3K, PPARα, and Sirt1 are essential components of the OMT-28-mediated pro-survival pathway. Counteracting inflammatory injury of cardiomyocytes, OMT-28 (1 μM) reduced LPS-induced increases in TNFα protein (by about 85% versus vehicle) and NF-κB DNA binding (by about 70% versus vehicle). In the ex vivo model, OMT-28 improved post-IR myocardial function recovery to reach about 40% of the baseline value compared to less than 20% with the vehicle. Furthermore, OMT-28 (1 μM) limited IR-induced NLRP3 inflammasome activation similarly to a direct NLRP3 inhibitor (MCC950). Overall, this study demonstrates that OMT-28 possesses potent cardio-protective and anti-inflammatory properties supporting the hypothesis that extending the bioavailability of omega-3 epoxyeicosanoids may improve their prospects as therapeutic agents.

Brain-gut photobiomodulation restores cognitive alterations in chronically stressed mice through the regulation of Sirt1 and neuroinflammation

BACKGROUND

Chronic stress is an important risk factor for the development of major depressive disorder (MDD). Recent studies have shown microbiome dysbiosis as one of the pathogenic mechanisms associated with MDD. Thus, it is important to find novel non-pharmacological therapeutic strategies that can modulate gut microbiota and brain activity. One such strategy is photobiomodulation (PBM), which involves the non-invasive use of light.

OBJECTIVE/HYPOTHESIS

Brain-gut PBM could have a synergistic beneficial effect on the alterations induced by chronic stress.

METHODS

We employed the chronic unpredictable mild stress (CUMS) protocol to induce a depressive-like state in mice. Subsequently, we administered brain-gut PBM for 6 min per day over a period of 3 weeks. Following PBM treatment, we examined behavioral, structural, molecular, and cellular alterations induced by CUMS.

RESULTS

We observed that the CUMS protocol induces profound behavioral alterations and an increase of sirtuin1 (Sirt1) levels in the hippocampus. We then combined the stress protocol with PBM and found that tissue-combined PBM was able to rescue cognitive alterations induced by CUMS. This rescue was accompanied by a restoration of hippocampal Sirt1 levels, prevention of spine density loss in the CA1 of the hippocampus, and the modulation of the gut microbiome. PBM was also effective in reducing neuroinflammation and modulating the morphology of Iba1-positive microglia.

LIMITATIONS

The molecular mechanisms behind the beneficial effects of tissue-combined PBM are not fully understood.

CONCLUSIONS

Our results suggest that non-invasive photobiomodulation of both the brain and the gut microbiome could be beneficial in the context of stress-induced MDD.

Understanding oocyte ageing

Females are born with a finite and non-renewable reservoir of oocytes, which therefore decline both in number and quality with advancing age. A striking characteristic of oocyte quality is that "ageing" effects manifest whilst women are in their thirties and are therefore still chronologically and physically young. Furthermore, this decline is unrelenting and not modifiable to any great extent by lifestyle or diet. Since oocyte quality is rate-limiting for pregnancy success, as the proportion of good-quality oocytes progressively deteriorate, the chance of successful pregnancy during each 6-12-month period also decreases, becoming exponential after 37 years. Unlike oocyte quality, age-related attrition in the size of the ovarian reservoir is less impactful for natural fertility since only one mature oocyte is typically ovulated per menstrual cycle. In contrast, oocyte numbers are pivotal for in-vitro fertilization success, since larger numbers enable better-quality oocytes to be found and is important for buffering the inefficiencies of the IVF process. The ageing trajectory is accelerated in ~10% of women, so-called premature ovarian ageing, with ~1% of women at the extreme end of this spectrum with loss of ovarian function occurring before 40 years of age, termed premature ovarian insufficiency. The aim of this review was to analyze how ageing impacts the size and quality of the oocyte pool along with emerging interventions for combating low oocyte numbers and improving quality.

The role of mitochondrial dysfunction in kidney injury and disease

Mitochondria are the main sites of aerobic respiration in the cell and mainly provide energy for the organism, and play key roles in adenosine triphosphate (ATP) synthesis, metabolic regulation, and cell differentiation and death. Mitochondrial dysfunction has been identified as a contributing factor to a variety of diseases. The kidney is rich in mitochondria to meet energy needs, and stable mitochondrial structure and function are essential for normal kidney function. Recently, many studies have shown a link between mitochondrial dysfunction and kidney disease, maintaining mitochondrial homeostasis has become an important target for kidney therapy. In this review, we integrate the role of mitochondrial dysfunction in different kidney diseases, and specifically elaborate the mechanism of mitochondrial reactive oxygen species (mtROS), autophagy and ferroptosis involved in the occurrence and development of kidney diseases, providing insights for improved treatment of kidney diseases.

The Antimicrobial Peptide Tilapia Piscidin 4 Induced the Apoptosis of Bladder Cancer Through ERK/SIRT1/PGC-1α Signaling Pathway

Marine antimicrobial peptides have been demonstrated in numerous studies to possess anti-cancer properties. This research investigation aimed to explore the fundamental molecular mechanisms underlying the antitumor activity of Tilapia piscidin 4 (TP4), an antimicrobial peptide, in human bladder cancer. TP4 exhibited a remarkable inhibitory effect on the proliferation of bladder cancer cells through cell cycle arrest at the G2/M phase. Additionally, TP4 upregulated the expression of cleaved caspase-3, caspase-9, and PARP, leading to the activation of apoptotic pathways in bladder cancer cells. TP4 exhibit a marked rise in mitochondria reactive oxygen species, leading to the subsequent loss of potential for the mitochondrial membrane. Furthermore, the inhibition of mitochondrial oxidative phosphorylation resulted in a decrease in downstream ATP production. Meanwhile, TP4-treated bladder cancer cells showed an increase in Bax and ERK but a decrease in SIRT1, PGC-1α, and Bcl2. ERK activation, SIRT1/PGC-1α-axis, and TP4-induced apoptosis were all significantly reversed by the ERK inhibitor SCH772984. Finally, the inhibitory effect of TP4 on tumor growth has been confirmed in a zebrafish bladder cancer xenotransplantation model. These findings suggest that TP4 may be a potential agents for human bladder cancer through apoptosis induction, ERK activation, and the promotion of SIRT1-mediated signaling pathways.

Repurposing Ketamine in the Therapy of Depression and Depression-Related Disorders: Recent Advances and Future Potential

Depression represents a prevalent and enduring mental disorder of significant concern within the clinical domain. Extensive research indicates that depression is very complex, with many interconnected pathways involved. Most research related to depression focuses on monoamines, neurotrophic factors, the hypothalamic-pituitary-adrenal axis, tryptophan metabolism, energy metabolism, mitochondrial function, the gut-brain axis, glial cell-mediated inflammation, myelination, homeostasis, and brain neural networks. However, recently, Ketamine, an ionotropic N-methyl-D-aspartate (NMDA) receptor antagonist, has been discovered to have rapid antidepressant effects in patients, leading to novel and successful treatment approaches for mood disorders. This review aims to summarize the latest findings and insights into various signaling pathways and systems observed in depression patients and animal models, providing a more comprehensive view of the neurobiology of anxious-depressive-like behavior. Specifically, it highlights the key mechanisms of ketamine as a rapid-acting antidepressant, aiming to enhance the treatment of neuropsychiatric disorders. Moreover, we discuss the potential of ketamine as a prophylactic or therapeutic intervention for stress-related psychiatric disorders.