Preventing loss of sirt1 lowers mitochondrial oxidative stress and preserves C2C12 myotube diameter in an in vitro model of cancer cachexia.

Cancer cachexia is a multifactorial syndrome associated with advanced cancer that contributes to mortality. Cachexia is characterized by loss of body weight and muscle atrophy. Increased skeletal muscle mitochondrial reactive oxygen species (ROS) is a contributing factor to loss of muscle mass in cachectic patients. Mice inoculated with Lewis lung carcinoma (LLC) cells lose weight, muscle mass, and have lower muscle sirtuin-1 (sirt1) expression. Nicotinic acid (NA) is a precursor to nicotinamide dinucleotide (NAD+) which is exhausted in cachectic muscle and is a direct activator of sirt1. Mice lost body and muscle weight and exhibited reduced skeletal muscle sirt1 expression after inoculation with LLC cells. C2C12 myotubes treated with LLC-conditioned media (LCM) had lower myotube diameter. We treated C2C12 myotubes with LCM for 24 h with or without NA for 24 h. C2C12 myotubes treated with NA maintained myotube diameter, sirt1 expression, and had lower mitochondrial superoxide. We then used a sirt1-specific small molecule activator SRT1720 to increase sirt1 activity. C2C12 myotubes treated with SRT1720 maintained myotube diameter, prevented loss of sirt1 expression, and attenuated mitochondrial superoxide production. Our data provides evidence that NA may be beneficial in combating cancer cachexia by maintaining sirt1 expression and decreasing mitochondrial superoxide production.

Inflammatory Changes after Medical Suppression of Suspected Endometriosis for Implantation Failure: Preliminary Results.

Unexplained euploid embryo transfer failure (UEETF) is a frustrating and unanswered conundrum accounting for 30 to 50% of failures in in vitro fertilization using preimplantation genetic testing for aneuploidy (PGT-A). Endometriosis is thought by many to account for most of such losses and menstrual suppression or surgery prior to the next transfer has been reported to be beneficial. In this study, we performed endometrial biopsy in a subset of women with UEETF, testing for the oncogene BCL6 and the histone deacetylase SIRT1. We compared 205 PGT-A cycles outcomes and provide those results following treatment with GnRH agonist versus controls (no treatment). Based on these and previous promising results, we next performed a pilot randomized controlled trial comparing the orally active GnRH antagonist, elagolix, to oral contraceptive pill (OCP) suppression for 2 months before the next euploid embryo transfer, and monitored inflammation and miRNA expression in blood, before and after treatment. These studies support a role for endometriosis in UEETF and suggest that medical suppression of suspected disease with GnRH antagonist prior to the next transfer could improve success rates and address underlying inflammatory and epigenetic changes associated with UEETF.

miR-485-3p targets SIRT1 in vascular smooth muscle cells mediating the occurrence of aortic dissection.

Studies have demonstrated a close correlation between MicroRNA and the occurrence of aortic dissection (AD). However, the molecular mechanisms underlying this relationship have not been fully elucidated and further exploration is still required. In this study, we found that miR-485-3p was significantly upregulated in human aortic dissection tissues. Meanwhile, we constructed in vitro AD models in HAVSMCs, HAECs and HAFs and found that the expression of miR-485-3p was increased only in HAVSMCs. Overexpression or knockdown of miR-485-3p in HAVSMCs could regulate the expression of inflammatory cytokines IL1ß, IL6, TNF-α, and NLRP3, as well as the expression of apoptosis-related proteins BAX/BCL2 and Cleaved caspase3/Caspase3. In the in vivo AD model, we have observed that miR-485-3p regulates vascular inflammation and apoptosis, thereby participating in the modulation of AD development in mice. Based on target gene prediction, we have validated that SIRT1 is a downstream target gene of miR-485-3p. Furthermore, by administering SIRT1 agonists and inhibitors to mice, we observed that the activation of SIRT1 alleviates vascular inflammation and apoptosis, subsequently reducing the incidence of AD. Additionally, functional reversal experiments revealed that overexpression of SIRT1 in HAVSMCs could reverse the cell inflammation and apoptosis mediated by miR-485-3p. Therefore, our research suggests that miR-485-3p can aggravate inflammation and apoptosis in vascular smooth muscle cells by suppressing the expression of SIRT1, thereby promoting the progression of aortic dissection.

Emodin alleviates cholestatic liver injury by modulating Sirt1/Fxr signaling pathways.

Emodin (EMO) has the effect of anti-cholestasis induced by alpha-naphthylisothiocyanate (ANIT). But its mechanism is still unclear. The farnesoid X receptor (Fxr) is the master bile acid nuclear receptor. Recent studies have reported that Sirtuin 1 (Sirt1) can regulate the activities of Fxr. The purpose of the current study was to investigate the mechanism of EMO against ANIT-induced liver injury based on Sirt1/Fxr signaling pathway. The ANIT-induced cholestatic rats were used with or without EMO treatment. Serum biochemical indicators, as well as liver histopathological changes were examined. The genes expressions of Sirt1, Fxr, Shp, Bsep and Mrp2 were detected. The expressions of Sirt1, Fxr and their downstream related genes were investigated in vitro. The results showed that EMO significantly alleviated ANIT-induced liver injury in rats, and increased Sirt1, Fxr, Shp, Bsep and Mrp2 gene expression in liver, while decreased the expression of Cyp7a1. EMO significantly activated Fxr, while Sirt1 inhibitor and Sirt1 gene silencing significantly reduced Fxr activity in vitro. Collectively, EMO in the right dose has a protective effect on liver injury induced by ANIT, and the mechanism may be through activation of Fxr by Sirt1, thus regulating bile acid metabolism, and reducing bile acid load in hepatocytes.

Resveratrol Alleviates Liver Fibrosis Induced by Long-Term Inorganic Mercury Exposure through Activating the Sirt1/PGC-1α Signaling Pathway.

Liver disease has become an important risk factor for global health. Resveratrol (Res) is a natural polyphenol which is widely found in foods and has a variety of biological activities. This study investigated the role of the microbiota-gut-liver axis in the Res relieving the liver fibrosis induced by inorganic mercury exposure. Twenty-eight mice were divided into four groups (n = 7) and treated with mercuric chloride and/or Res for 24 weeks, respectively. The results showed that Res mitigated the ileum injury induced by inorganic mercury and restrained LPS and alcohol entering the body circulation. Network pharmacological and molecular analyses showed that Res alleviated oxidative stress, metabolism disorders, inflammation, and hepatic stellate cell activation in the liver. In conclusion, Res alleviates liver fibrosis induced by inorganic mercury via activating the Sirt1/PGC-1α signaling pathway and regulating the microbial-gut-liver axis, particularly, increasing the relative enrichment of Bifidobacterium in the intestinal tract.

Vitamin D alleviation of oxidative stress in human retinal pigment epithelial cells.

BACKGROUND: Oxidative stress-induced retinal pigment epithelium (RPE) cell damage is a major factor in age-related macular degeneration (AMD). Vitamin D3 (VD3) is a powerful antioxidant and it has been suggested to have anti-aging properties and potential for treating AMD. This study aimed to investigate the effect of VD3 on RPE cell oxidative apoptosis of RPE cells in order to provide experimental evidence for the treatment of AMD. METHODS: Human retinal pigment epithelial cell 19 (ARPE-19) cells were divided into four groups: blank group (untreated), model group (incubated in medium with 400 µmol/L H2O2 for 1 h), VD3 group (incubated in medium with 100 µmol/L VD3 for 24 h), and treatment group (incubated in medium with 400 µmol/L H2O2 for 1 h and 100 µmol/L VD3 for 24 h). Cell viability, cell senescence, ROS content, expression levels of vitamin D specific receptors, Akt, Sirt1, NAMPT, and JNK mRNA expression levels, SOD activity, and MDA, GSH, and GPX levels were measured. RESULTS: We first established an ARPE-19 cell stress model with H2O2. Our control experiment showed that VD3 treatment had no significant effect on ARPE-19 cell viability within 6-48 h. Treating the stressed ARPE-19 cells with VD3 showed mixed results; caspase-3 expression was decreased, Bcl-2 expression was increased, MDA level of ARPE-19 cells was decreased, GSH-PX, GPX and SOD levels were increased, the relative mRNA expression levels of Akt, Sirt1, NAMPT were increased (P < 0.05), and the relative mRNA expression level of JNK was decreased (P < 0.05). CONCLUSION: VD3 can potentially slow the development of AMD.

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.

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. ß-hydroxybutyric acid (ß-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 ß-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.

Lactate transported by MCT1 plays an active role in promoting mitochondrial biogenesis and enhancing TCA flux in skeletal muscle.

Once considered as a "metabolic waste," lactate is now recognized as a major fuel for tricarboxylic acid (TCA) cycle. Our metabolic flux analysis reveals that skeletal muscle mainly uses lactate to fuel TCA cycle. Lactate is transported through the cell membrane via monocarboxylate transporters (MCTs) in which MCT1 is highly expressed in the muscle. We analyzed how MCT1 affects muscle functions using mice with specific deletion of MCT1 in skeletal muscle. MCT1 deletion enhances running performance, increases oxidative fibers while decreasing glycolytic fibers, and enhances flux of glucose to TCA cycle. MCT1 deficiency increases the expression of mitochondrial proteins, augments cell respiration rate, and elevates mitochondrial activity in the muscle. Mechanistically, the protein level of PGC-1α, a master regulator of mitochondrial biogenesis, is elevated upon loss of MCT1 via increases in cellular NAD+ level and SIRT1 activity. Collectively, these results demonstrate that MCT1-mediated lactate shuttle plays a key role in regulating muscle functions by modulating mitochondrial biogenesis and TCA flux.

Sirtuin1 (sirt1) regulates the glycolysis pathway and decreases cisplatin chemotherapeutic sensitivity to esophageal squamous cell carcinoma.

We aimed to evaluate the influence of sirtuin1 (sirt1) on the ESCC chemotherapeutic sensitivity to cisplatin. We used ESCC cell ablation sirt1 for establishing a xenograft mouse tumor model. The tumor volume was then detected. sirt1 was over-expressed significantly in ESCC patients and cells. Moreover, sirt1 knockdown raised ESCC sensitivity to cisplatin. Besides, glycolysis was associated with ESCC cell chemotherapy resistance to cisplatin. Furthermore, sirt1 increased ESCC cells' cisplatin chemosensitivity through HK2. Sirt1 enhanced in vivo ESCC chemosensitivity to cisplatin. Overall, these findings suggested that sirt1 knockdown regulated the glycolysis pathway and raised the ESCC chemotherapeutic sensitivity.

The mitochondrial protease ClpP is a druggable target that controls VSMC phenotype by a SIRT1-dependent mechanism.

Vascular smooth muscle cells (VSMCs), known for their remarkable lifelong phenotypic plasticity, play a pivotal role in vascular pathologies through their ability to transition between different phenotypes. Our group discovered that the deficiency of the mitochondrial protein Poldip2 induces VSMC differentiation both in vivo and in vitro. Further comprehensive biochemical investigations revealed Poldip2's specific interaction with the mitochondrial ATPase caseinolytic protease chaperone subunit X (CLPX), which is the regulatory subunit for the caseinolytic protease proteolytic subunit (ClpP) that forms part of the ClpXP complex - a proteasome-like protease evolutionarily conserved from bacteria to humans. This interaction limits the protease's activity, and reduced Poldip2 levels lead to ClpXP complex activation. This finding prompted the hypothesis that ClpXP complex activity within the mitochondria may regulate the VSMC phenotype. Employing gain-of-function and loss-of-function strategies, we demonstrated that ClpXP activity significantly influences the VSMC phenotype. Notably, both genetic and pharmacological activation of ClpXP inhibits VSMC plasticity and fosters a quiescent, differentiated, and anti-inflammatory VSMC phenotype. The pharmacological activation of ClpP using TIC10, currently in phase III clinical trials for cancer, successfully replicates this phenotype both in vitro and in vivo and markedly reduces aneurysm development in a mouse model of elastase-induced aortic aneurysms. Our mechanistic exploration indicates that ClpP activation regulates the VSMC phenotype by modifying the cellular NAD+/NADH ratio and activating Sirtuin 1. Our findings reveal the crucial role of mitochondrial proteostasis in the regulation of the VSMC phenotype and propose the ClpP protease as a novel, actionable target for manipulating the VSMC phenotype.

Cardiotoxicity Induced by Intratracheal Instillation of Diesel Exhaust Particles in Mice, and the Protective Effects of Carnosol: Suppression of Inflammation and Oxidative and Nitrosative Stress via Modulation of NF-κb/MAPKs Signaling Pathways.

BACKGROUND/AIMS: Inhaled particulate air pollution is associated with cardiotoxicity with underlying mechanisms including oxidative stress and inflammation. Carnosol, commonly found in rosemary and sage, is known to possess a broad range of therapeutic properties such as antioxidant, anti-inflammatory and antiapoptotic. However, its cardioprotective effects on diesel exhaust particles (DEPs)-induced toxicity have not been studied yet. Hence, we evaluated the potential ameliorative effects of carnosol on DEPs-induced heart toxicity in mice, and the underlying mechanisms involved. METHODS: Mice were intratracheally instilled with DEPs (1 mg/kg) or saline, and 1 hour prior to instillation they were given intraperitoneally either carnosol (20 mg/kg) or saline. Twenty-four hours after the DEPs instillation, multiple parameters were evaluated in the heart by enzyme-linked immunosorbent assay, colorimetric assay, Comet assay and Western blot technique. RESULTS: Carnosol has significantly reduced the elevation in the plasma levels of lactate hydrogenase and brain natriuretic peptide induced by DEPs. Likewise, the augmented cardiac levels of proinflammatory cytokines, lipid peroxidation, and total nitric oxide in DEPs-treated groups were significantly normalized with the treatment of carnosol. Moreover, carnosol has markedly reduced the heart mitochondrial dysfunction, as well as DNA damage and apoptosis of mice treated with DEPs. Similarly, carnosol significantly reduced the elevated expressions of phosphorylated nuclear factor-кB (NF-кB) and mitogen-activated protein kinases (MAPKs) in the hearts. Furthermore, the treatment with carnosol has restored the decrease in the expression of sirtuin-1 in the hearts of mice exposed to DEPs. CONCLUSION: Carnosol significantly attenuated DEP-induced cardiotoxicity in mice by suppressing inflammation, oxidative stress, DNA damage, and apoptosis, at least partly via mechanisms involving sirtuin-1 activation and the inhibition of NF-кB and MAPKs activation.

Organic light-emitting diode therapy promotes longevity through the upregulation of SIRT1 in senescence-accelerated mouse prone 8 mice.

Phototherapy has been extensively used to prevent and treat signs of aging and stimulate wound healing, and phototherapy through light-emitting diodes (LEDs). In contrast to LED, organic LED (OLED) devices are composed of organic semiconductors that possess novel characteristics. We investigated the regenerative potential of OLED for restoring cellular potential from senescence and thus delaying animal aging. Bone marrow-derived stem cells (BMSCs) and adipose-derived stem cells (ADSCs) were isolated from the control and OLED- treated groups to evaluate their proliferation, migration, and differentiation potentials. Cellular senescence was evaluated using a senescence-associated ß-galactosidase (SA-ß-gal) activity assay and gene expression biomarker assessment. OLED treatment significantly increased the cell proliferation, colony formation, and migration abilities of stem cells. SA-ß-gal activity was significantly decreased in both ADSCs and BMSCs in the OLED-treated group. Gene expression biomarkers from treated mice indicated a significant upregulation of IGF-1 (insulin growthfactor-1). The upregulation of the SIRT1 gene inhibited the p16 and p19 genes then to downregulate the p53 expressions for regeneration of stem cells in the OLED-treated group. Our findings indicated that the survival rates of 10-month aging senescence-accelerated mouse prone 8 mice were prolonged and that their gross appearance improved markedly after OLED treatment. Histological analysis of skin and brain tissue also indicated significantly greater collagen fibers density, which prevents ocular abnormalities and ß-amyloid accumulation. Lordokyphosis and bone characteristics were observed to resemble those of younger mice after OLED treatment. In conclusion, OLED therapy reduced the signs of aging and enhanced stem-cell senescence recovery and then could be used for tissue regeneration.

Melatonin Delays Arthritis Inflammation and Reduces Cartilage Matrix Degradation through the SIRT1-Mediated NF-κB/Nrf2/TGF-ß/BMPs Pathway.

Cartilage, a flexible and smooth connective tissue that envelops the surfaces of synovial joints, relies on chondrocytes for extracellular matrix (ECM) production and the maintenance of its structural and functional integrity. Melatonin (MT), renowned for its anti-inflammatory and antioxidant properties, holds the potential to modulate cartilage regeneration and degradation. Therefore, the present study was devoted to elucidating the mechanism of MT on chondrocytes. The in vivo experiment consisted of three groups: Sham (only the skin tissue was incised), Model (using the anterior cruciate ligament transection (ACLT) method), and MT (30 mg/kg), with sample extraction following 12 weeks of administration. Pathological alterations in articular cartilage, synovium, and subchondral bone were evaluated using Safranin O-fast green staining. Immunohistochemistry (ICH) analysis was employed to assess the expression of matrix degradation-related markers. The levels of serum cytokines were quantified via Enzyme-linked immunosorbent assay (ELISA) assays. In in vitro experiments, primary chondrocytes were divided into Control, Model, MT, negative control, and inhibitor groups. Western blotting (WB) and Quantitative RT-PCR (q-PCR) were used to detect Silent information regulator transcript-1 (SIRT1)/Nuclear factor kappa-B (NF-κB)/Nuclear factor erythroid-2-related factor 2 (Nrf2)/Transforming growth factor-beta (TGF-ß)/Bone morphogenetic proteins (BMPs)-related indicators. Immunofluorescence (IF) analysis was employed to examine the status of type II collagen (COL2A1), SIRT1, phosphorylated NF-κB p65 (p-p65), and phosphorylated mothers against decapentaplegic homolog 2 (p-Smad2). In vivo results revealed that the MT group exhibited a relatively smooth cartilage surface, modest chondrocyte loss, mild synovial hyperplasia, and increased subchondral bone thickness. ICH results showed that MT downregulated the expression of components related to matrix degradation. ELISA results showed that MT reduced serum inflammatory cytokine levels. In vitro experiments confirmed that MT upregulated the expression of SIRT1/Nrf2/TGF-ß/BMPs while inhibiting the NF-κB pathway and matrix degradation-related components. The introduction of the SIRT1 inhibitor Selisistat (EX527) reversed the effects of MT. Together, these findings suggest that MT has the potential to ameliorate inflammation, inhibit the release of matrix-degrading enzymes, and improve the cartilage condition. This study provides a new theoretical basis for understanding the role of MT in decelerating cartilage degradation and promoting chondrocyte repair in in vivo and in vitro cultured chondrocytes.

SIRT1 mediates the excitability of spinal CaMKIIα-positive neurons and participates in neuropathic pain by controlling Nav1.3.

AIMS: Neuropathic pain is a common chronic pain disorder, which is largely attributed to spinal central sensitization. Calcium/calmodulin-dependent protein kinase II alpha (CaMKIIα) activation in the spinal dorsal horn (SDH) is a major contributor to spinal sensitization. However, the exact way that CaMKIIα-positive (CaMKIIα+) neurons in the SDH induce neuropathic pain is still unclear. This study aimed to explore the role of spinal CaMKIIα+ neurons in neuropathic pain caused by chronic constriction injury (CCI) and investigate the potential epigenetic mechanisms involved in CaMKIIα+ neuron activation. METHODS: CCI-induced neuropathic pain mice model, Sirt1loxP/loxP mice, and chemogenetic virus were used to investigate whether the activation of spinal CaMKIIα+ neurons is involved in neuropathic pain and its involved mechanism. Transcriptome sequence, western blotting, qRT-PCR, and immunofluorescence analysis were performed to assay the expression of related molecules and activation of neurons. Co-immunoprecipitation was used to observe the binding relationship of protein. Chromatin immunoprecipitation (ChIP)-PCR was applied to analyze the acetylation of histone H3 in the Scn3a promoter region. RESULTS: The expression of sodium channel Nav1.3 was increased and the expression of SIRT1 was decreased in the spinal CaMKIIα+ neurons of CCI mice. CaMKIIα neurons became overactive after CCI, and inhibiting their activation relieved CCI-induced pain. Overexpression of SIRT1 reversed the increase of Nav1.3 and alleviated pain, while knockdown of SIRT1 or overexpression of Nav1.3 promoted CaMKIIα+ neuron activation and induced pain. By knocking down spinal SIRT1, the acetylation of histone H3 in the Scn3a (encoding Nav1.3) promoter region was increased, leading to an increased expression of Nav1.3. CONCLUSION: The findings suggest that an aberrant reduction of spinal SIRT1 after nerve injury epigenetically increases Nav1.3, subsequently activating CaMKIIα+ neurons and causing neuropathic pain.

Neratinib stimulates senescence of mammary cancer cells by reducing the levels of SIRT1.

Neratinib, a typical small-molecule, pan-human tyrosine kinase inhibitor (TKI), has been licensed for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, the underlying pharmacological mechanism is still unknown. In the current study, we report a novel function of Neratinib by showing that its treatment stimulates senescence of the mammary cancer AU565 cells. Our results demonstrate that Neratinib induces mitochondrial injury by increasing mitochondrial reactive oxygen species (ROS) and reducing intracellular adenosine triphosphate (ATP). Also, we found that Neratinib induced DNA damage by increasing the levels of 8-Hydroxy-desoxyguanosine (8-OHdG) and γH2AX in AU565 cells. Additionally, Neratinib reduced the levels of telomerase activity after 7 and 14 days incubation. Importantly, the senescence-associated-ß-galactosidase (SA-ß-Gal) assay revealed that Neratinib stimulated senescence of AU565 cells. Neratinib decreased the gene levels of human telomerase reverse transcriptase (hTERT) but increased those of telomeric repeat-binding factor 2 (TERF2) in AU565 cells. Further study displayed that Neratinib upregulated the expression of K382 acetylation of p53 (ac-K382) and p21 but reduced the levels of sirtuin-1 (SIRT1). However, overexpression of SIRT1 abolished the effects of Neratinib in cellular senescence. These findings provide strong preclinical evidence of Neratinib's treatment of breast cancer.

Mannan-binding lectin inhibits oxidative stress-induced senescence via the NAD+/Sirt1 pathway.

Prolonged or excessive oxidative stress can lead to premature cellular and body aging. Mannan-binding lectin (MBL) is synthesized by the liver and plays an important role in innate immunity, anti-inflammation, and anti-oxidation, and has a positive impact on health and longevity. To date, few studies investigated the role of MBL in attenuating oxidative stress-induced senescence. In this study, we evaluated the role of MBL in oxidative stress-induced premature aging and explored its underlying mechanism in C57BL/6 mice and mouse embryonic fibroblasts (NIH/3T3). First, we established an oxidative premature senescence model induced by D-galactose in C57BL/6 mice. We found that MBL-deficient mice had a marked aging-like appearance, reduced learning and spatial exploration abilities, severe liver pathological damage, and significantly upregulated expression of Senescence-associated proteins (p53 and p21), inflammatory kinesins (IL-1ß and IL-6), and the senescence ß-galactosidase (SA-ß-Gal) positive rate as compared with WT mice. In the H2O2-induced oxidative senescence model of NIH/3T3 cells, consistent results were obtained after MBL intervention. In addition, MBL effectively inhibited G1 phase arrest, ROS levels, DNA damage, and mitochondrial dysfunction in premature senescent cells. Mechanistically, we found that oxidative stress inhibited the nicotinamide adenine dinucleotide (NAD+)/ silent information regulator 1 (Sirt1) signaling pathway, while MBL activated the NAD+/Sirt1 signaling pathway inhibited by oxidative stress. In addition, MBL could activate the NAD+/Sirt1 pathway by upregulating NAMPT, which in turn inhibited p38 phosphorylation by activating the NAD+/Sirt1 pathway. In conclusion, MBL inhibits oxidative aging, which may facilitate the development of therapeutics to delay oxidative aging.

Autophagic signaling promotes systems-wide remodeling in skeletal muscle upon oncometabolic stress by D2-HG.

OBJECTIVES: Cachexia is a metabolic disorder and comorbidity with cancer and heart failure. The syndrome impacts more than thirty million people worldwide, accounting for 20% of all cancer deaths. In acute myeloid leukemia, somatic mutations of the metabolic enzyme isocitrate dehydrogenase 1 and 2 cause the production of the oncometabolite D2-hydroxyglutarate (D2-HG). Increased production of D2-HG is associated with heart and skeletal muscle atrophy, but the mechanistic links between metabolic and proteomic remodeling remain poorly understood. Therefore, we assessed how oncometabolic stress by D2-HG activates autophagy and drives skeletal muscle loss. METHODS: We quantified genomic, metabolomic, and proteomic changes in cultured skeletal muscle cells and mouse models of IDH-mutant leukemia using RNA sequencing, mass spectrometry, and computational modeling. RESULTS: D2-HG impairs NADH redox homeostasis in myotubes. Increased NAD+ levels drive activation of nuclear deacetylase Sirt1, which causes deacetylation and activation of LC3, a key regulator of autophagy. Using LC3 mutants, we confirm that deacetylation of LC3 by Sirt1 shifts its distribution from the nucleus into the cytosol, where it can undergo lipidation at pre-autophagic membranes. Sirt1 silencing or p300 overexpression attenuated autophagy activation in myotubes. In vivo, we identified increased muscle atrophy and reduced grip strength in response to D2-HG in male vs. female mice. In male mice, glycolytic intermediates accumulated, and protein expression of oxidative phosphorylation machinery was reduced. In contrast, female animals upregulated the same proteins, attenuating the phenotype in vivo. Network modeling and machine learning algorithms allowed us to identify candidate proteins essential for regulating oncometabolic adaptation in mouse skeletal muscle. CONCLUSIONS: Our multi-omics approach exposes new metabolic vulnerabilities in response to D2-HG in skeletal muscle and provides a conceptual framework for identifying therapeutic targets in cachexia.

Understanding the Impact of the Sirtuin 1 (SIRT1) Gene on Age-related Macular Degeneration: A Comprehensive Study.

Age-related macular degeneration (AMD) is a prevalent and incurable condition affecting the central retina and posing a significant risk to vision, particularly in individuals over the age of 60. As the global population ages, the prevalence of AMD is expected to rise, leading to substantial socioeconomic impacts and increased healthcare costs. The disease manifests primarily in two forms, neovascular and non-neovascular, with genetic, environmental and lifestyle factors playing a pivotal role in disease susceptibility and progression. This review article involved conducting an extensive search across various databases, including Google Scholar, PubMed, Web of Science, ScienceDirect, Scopus and EMBASE, to compile relevant case-control studies and literature reviews from online published articles extracted using search terms related to the work. SIRT1, a key member of the sirtuin family, influences cellular processes such as ageing, metabolism, DNA repair and stress response. Its dysregulation is linked to retinal ageing and ocular conditions like AMD. This review discusses the role of SIRT1 in AMD pathology, its association with genetic variants and its potential as a biomarker, paving the way for targeted interventions and personalised treatment strategies. In addition, it highlights the findings of case-control studies investigating the relationship between SIRT1 gene polymorphisms and AMD risk. These studies collectively revealed a significant association between certain SIRT1 gene variants and AMD risk. Further studies with larger sample sizes are required to validate these findings. As the prevalence of AMD grows, understanding the role of SIRT1 and other biomarkers becomes increasingly vital for improving diagnosis, treatment and, ultimately, patient outcomes.

LncRNA Peg13 Alleviates Myocardial Infarction/Reperfusion Injury through Regulating MiR-34a/Sirt1-Mediated Endoplasmic Reticulum Stress.

Myocardial infarction/reperfusion (I/R) injury significantly impacts the health of older individuals. We confirmed that the level of lncRNA Peg13 was downregulated in I/R injury. However, the detailed function of Peg13 in myocardial I/R injury has not yet been explored.To detect the function of Peg13, in vivo model of I/R injury was constructed. RT-qPCR was employed to investigate RNA levels, and Western blotting was performed to assess levels of endoplasmic reticulum stress and apoptosis-associated proteins. EdU staining was confirmed to assess the cell proliferation.I/R therapy dramatically produced myocardial injury, increased the infarct area, and decreased the amount of Peg13 in myocardial tissues of mice. In addition, hypoxia/reoxygenation (H/R) notably induced the apoptosis and promoted the endoplasmic reticulum (ER) stress of HL-1 cells, while overexpression of Peg13 reversed these phenomena. Additionally, Peg13 may increase the level of Sirt1 through binding to miR-34a. Upregulation of Peg13 reversed H/R-induced ER stress via regulation of miR-34a/Sirt1 axis.LncRNA Peg13 reduces ER stress in myocardial infarction/reperfusion injury through mediation of miR-34a/Sirt1 axis. Hence, our research might shed new lights on developing new strategies for the treatment of myocardial I/R injury.