Sirtuin 1 Levels Research Articles

Calycosin‑7‑O‑β‑D‑glucoside downregulates mitophagy by mitigating mitochondrial fission to protect HT22 cells from oxygen‑glucose deprivation/reperfusion‑induced injury.

Calycosin‑7‑O‑β‑D‑glucoside (CG), a major active ingredient of Astragali Radix, exerts neuroprotective effects against cerebral ischemia; however, whether the effects of CG are associated with mitochondrial protection remains unclear. The present study explored the role of CG in improving mitochondrial function in a HT22 cell model of oxygen‑glucose deprivation/reperfusion (OGD/R). The Cell Counting Kit‑8 assay, flow cytometry, immunofluorescence and western blotting were performed to investigate the effects of CG on mitochondrial function. The results demonstrated that mitochondrial function was restored after treatment with CG, as indicated by reduced mitochondrial reactive oxygen species levels, increased mitochondrial membrane potential and improved mitochondrial morphology. Overactivated mitophagy was revealed to be inhibited by the regulation of proteins involved in fission [phosphorylated‑dynamin‑related protein 1 (Drp1) and Drp1] and mitophagy (LC3, p62 and translocase of outer mitochondrial membrane 20), and mitochondrial biogenesis was demonstrated to be enhanced by increased levels of sirtuin 1 (SIRT1) and peroxisome proliferator‑activated receptor γ coactivator‑1α (PGC‑1α). In addition, neuronal apoptosis was ameliorated by CG, as determined by a decreased rate of apoptosis, and levels of caspase‑3 and Bcl‑2/Bax. In conclusion, the present study demonstrated that CG may alleviate OGD/R‑induced injury by upregulating SIRT1 and PGC‑1α protein expression, and reducing excessive mitochondrial fission and overactivation of mitophagy.

Integrated analysis of non‑coding RNAs (HOTAIR and miR‑130a) and their cross‑talk with TGF‑β1, SIRT1 and E‑cadherin as potential biomarkers in colorectal cancer.

Molecular changes have a substantial impact on the onset of colorectal cancer (CRC). Complexes of HOTAIR and miRNAs disrupt several cellular functions during carcinogenesis, primarily by disrupting several carcinogenic signaling pathways. In the present study, the relationships between the serum levels of transforming growth factor-β1 (TGF-β1), sirtuin-1 (SIRT1) and E-cadherin and those of HOX transcript antisense intergenic RNA (HOTAIR) and microRNA-130a (miR-130a) in individuals with CRC were analyzed, including their correlations and diagnostic potential. Patients with colon cancer and healthy volunteers were enrolled in the study. Blood samples were collected from 70 patients with CRC and 30 age-matched healthy control volunteers and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine the serum levels of HOTAIR and miR-130a. In addition, the levels of TGF-β1, SIRT1 and E-cadherin were determined utilizing enzyme-linked immunosorbent assays. Patients with CRC were found to have significantly higher TGF-β1, SIRT1, HOTAIR and miR-130a serum levels than those of healthy participants. In addition, patients with high-grade CRC had significantly higher levels of TGF-β1, SIRT1, HOTAIR and miR-130a compared with those of patients with low-grade CRC. A significant reduction in the serum levels of E-cadherin was observed in participants with CRC compared with healthy participants, but no significant difference was detected according to the grade of CRC. Positive correlations were found between HOTAIR and miR-130a, as well as TGF-β1 and SIRT1. By contrast, negative correlations were noted between E-cadherin and HOTAIR, miR-130a, TGF-β1 and SIRT1. Therefore, it may be concluded that the miR-130a/HOTAIR and TGF-β1/SIRT1/E-cadherin axes may serve as novel biomarkers for the early diagnosis of CRC.

PGC-1α Promotes Mitochondrial Biosynthesis and Energy Metabolism of Goose Fatty Liver

To investigate the functions of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in the goose fatty liver, a total of 30 healthy 63-day-old male Landes geese were selected and randomly assigned to control group and overfeeding group. The overexpression or RNA interference assay of PGC-1α was performed in goose primary hepatocytes. Our data showed that the PGC-1α expression was increased in fatty liver. The abundance of mitochondrial biosynthesis-related and energy metabolism-related genes, including mitochondrial transcription factor A (TFAM), mitochondrial transcription factor B1 (TFB1M), mitochondrial transcription factor B2 (TFB2M), nuclear respiratory factor 1 (NRF1), DNA topoisomerase I mitochondrial (TOP1MT), peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC-1β), sirtuin 3 (SIRT3), mitochondrially encoded cytochrome B (CYTB), and AMP-activated protein kinase alpha (AMPKα) were significantly increased in fatty liver. The abundance of TFAM, TFB1M, TFB2M, NRF1, and TOP1MT transcript was induced by PGC-1α overexpression, but inhibited by PGC-1α interference in primary hepatocytes. The mRNA expression levels of PGC-1β, SIRT3, SIRT5, CYTB, and AMPKα were significantly enhanced after PGC-1α overexpression. However, the mRNA expression levels of PGC-1β, SIRT5 and AMPKα were decreased after PGC-1α interference. Furthermore, we observed a significant increase in the mitochondrial DNA (mtDNA) copy number, the activity of mitochondrial respiratory chain complex Ⅳ (MRCC Ⅳ), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), and the NAD+/NADH ratio in fatty liver. But the activity of MRCC Ⅴ, as well as the levels of ADP and ATP in fatty liver were reduced. Additionally, the mtDNA copy number, the activity of MRCC Ⅰ, MRCC Ⅲ-Ⅴ, SDH, and MDH, and NAD+/NADH ratio were enhanced by PGC-1α overexpression; Whereas the mtDNA copy number, the activity of MRCC Ⅰ, SDH, and MDH, and the ratio of NAD+/NADH were inhibited by PGC-1α interference. In conclusion, these findings suggest that PGC-1α improves mitochondrial biosynthesis and energy metabolism in goose fatty liver, which may be an adaptive mechanism for goose fatty liver to cope with steatosis.

Semaglutide protects against diabetes-associated cardiac inflammation via Sirt3-dependent RKIP pathway.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) exert cardiovascular benefits in diabetic patients, but the underlying mechanisms remain incompletely understood. Semaglutide, a novel long-acting GLP-1RA, has shown a reduced risk of cardiovascular events. Based on these results, we investigated the therapeutic potential of semaglutide in diabetic cardiomyopathy and sought to elucidate the underlying mechanisms. Mice with diabetes induced by high-fat diet/streptozotocin were treated with semaglutide. The mechanisms underlying the cardioprotective effects of semaglutide were analysed using animal and cell experiments. In diabetic mice, semaglutide alleviated metabolic disorders, ameliorated myocardial fibrosis, improved cardiac function, antagonized oxidative stress and suppressed cardiomyocyte apoptosis. More significantly, semaglutide attenuated cardiac inflammation through restoring Raf kinase inhibitor protein (RKIP) expression and inhibiting downstream TANK-binding kinase 1 (TBK1)-NF-κB pathway. Meanwhile, decreased RKIP expression and activated TBK1-NF-κB signalling pathway were also found in tissues from human diabetic hearts. RKIP deficiency exacerbated cardiac inflammation and offset the cardioprotective effect of semaglutide in diabetic mice. Moreover, semaglutide also restored the expression level of Sirtuin 3(Sirt3), which served as a modulator against cardiac inflammation by regulating RKIP-dependent pathway. In diabetic mice, RKIP deficiency abolished the cardioprotective benefits conferred by the Sirt3 activator honokiol. We also found that cAMP/PKA signalling, rather than glucose lowering, contributed to the anti-inflammatory effect of semaglutide through Sirt3-dependent RKIP pathway. Semaglutide exerted cardioprotective effects against diabetic heart failure by alleviating cardiac inflammation through Sirt3-dependent RKIP signalling pathway.

Exercise training alleviates neuronal apoptosis and re-establishes mitochondrial quality control after cerebral ischemia by increasing SIRT3 expression

Existing evidence indicates that exercise training can enhance neural function by regulating mitochondrial quality control (MQC), which can be impaired by cerebral ischemia, and that sirtuin-3 (SIRT3), a protein localized in mitochondria, is crucial in maintaining mitochondrial functions. However, the relationship among exercise training, SIRT3, and MQC after cerebral ischemia remains obscure. This study attempted to elucidate the relationship among exercise training, SIRT3 and MQC after cerebral ischemia in rats. Male adult SD rats received tMCAO after the transfection of adeno-associated virus encoding either sirtuin-3 (AAV-SIRT3) or SIRT3 knockdown (AAV-sh-SIRT3) into the ipsilateral striata and cortex. Subsequently, the animals were randomly selected for exercise training. The index changes were measured by transmission electron microscopy, Western blot analysis, nuclear magnetic resonance imaging, TUNEL staining, and immunofluorescence staining, etc. The results revealed that after cerebral ischemia, exercise training increased SIRT3 expression, significantly improved neural function, alleviated infarct volume and neuronal apoptosis, maintained the mitochondrial structural integrity, and re-established MQC. The latter promoted mitochondrial biogenesis, balanced mitochondrial fission/fusion, and enhanced mitophagy. These favorable benefits were reversed after SIRT3 interference. In addition, a cellular OGD/R model showed that the increased SIRT3 expression alleviates neuronal apoptosis and re-establishes mitochondrial quality control by activating the β-catenin pathway. These findings suggest that exercise training may optimize mitochondrial quality control by increasing the expression of SIRT3, thereby improving neural functions after cerebral ischemia, which illuminates the mechanism underlying the exercise training-conferred neural benefits and indicates SIRT3 as a therapeutic strategy for brain ischemia.Graphical 1. The expression of SIRT3 decreases after cerebral ischemia in rats, while exercise training can increase SIRT3 levels in ischemic rats.2. Exercise training alleviates neuronal apoptosis and re-establishes mitochondrial quality control (MQC) after cerebral ischemia by increasing SIRT3 expression, thereby promoting neurological function recovery.3. SIRT3 overexpression reduces neuronal apoptosis and re-establishes MQC by activating the β-catenin pathway.

Hippocampal SIRT1 signaling mediates the ameliorative effect of treadmill exercise on anxiety- and depression-like behavior in APP/PS1 mice.

Anxiety and depression-like symptoms occur in the early stages of Alzheimer's disease. Hippocampal Sirtuin 1 (SIRT1) signaling mediates anxiety- and depression-like behavior. Exercise training improves anxiety and depression-like behavior in various disease models, such as the rat chronic restraint stress model, rat model of posttraumatic stress disorder, and rat model of fetal alcohol spectrum disorders. Here, we aimed to investigate whether exercise ameliorates anxiety- and depression like behaviors in APP/PS1 mice and explore the potential mechanisms. After eight weeks of exercise intervention, we assessed anxiety- and depression-like behaviors in Alzheimer's disease (AD) model mice. We then measured the levels of SIRT1, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), and mitochondrial biogenesis (CO2, ATP6, and mitochondrial content) using immunofluorescence, reverse transcription-quantitative real-time PCR, and transmission electron microscopy. Finally, we investigated the effects of pharmacological activation of SIRT1 on anxiety- and depression-like behaviors, the SIRT1/PGC-1α/NRF1/TFAM signaling axis, and mitochondrial biogenesis. We first observed that treadmill exercise improved anxiety- and depression-like behaviors in six-month-old APP/PS1 mice and increased SIRT1 levels in the hippocampus. Pharmacological activation of hippocampal SIRT1 function also reduced anxiety and depression-like behaviors in APP/PS1 mice. Meanwhile, both treadmill exercise and pharmacological activation of hippocampal SIRT1 increased the levels of PGC1α, NRF1, TFAM, and enhanced mitochondrial biogenesis (CO2, ATP6, or mitochondrial content) in the hippocampus of APP/PS1 mice. These findings reveal that treadmill exercise reduces anxiety- and depression-like behaviors in six-month-old APP/PS1 mice by enhancing the SIRT1-dependent PGC-1α/NRF1/TFAM axis, promoting mitochondrial biogenesis in the hippocampus.

The Influence of Nordic Walking Training on the Serum Levels of Sirtuins, FOXO3a, and Vitamin D Metabolites in Patients with Multiple Myeloma.

Multiple myeloma, a malignancy of plasma cells, often involves the disruption of vitamin D metabolism. Vitamin D, acting through its receptor (VDR), affects transcription factors like FOXO and sirtuins, which regulate cellular processes. The impact of physical activity on these markers in multiple myeloma patients is unclear. Therefore, the objective of this study was to evaluate the effects of a 6-week training program on these parameters. The study was completed by 30 patients, including 16 in the Nordic walking training group (TG) and 14 in the control group (non-exercising, CG). All participants underwent a thorough medical interview before starting the project. Venous blood samples were collected from all participants four times-at baseline, after 3 weeks, after 6 weeks, and after 9 weeks (follow-up). The serum concentrations of sirtuin 1, sirtuin 3, Foxo3a, vitamin D receptor (VDR), 25(OH)D3, and 1,25(OH)2D were determined. Body composition, physical fitness, and physical activity level were assessed at baseline and after 6 weeks. No statistically significant changes were observed in the serum levels of sirtuins, the FOXO3a protein, and 1,25(OH)2D. A statistically significant difference was observed in the levels of VDR for both time and group factors, but this was not confirmed in the post hoc test. Vitamin 25(OH)D3 level increased significantly in the study group with time. The applied 6-week Nordic walking training cycle positively affected the level of vitamin 25(OH)D3 but did not influence the rest of the biochemical parameters studied. The obtained results also indicate that the applied intervention is safe for patients and does not interfere with body composition.

Astragaloside IV Alleviates Acute Hepatic Injury by Regulating Macrophage Polarization and Pyroptosis via Activation of the AMPK/SIRT1 Signaling Pathway.

Acute hepatic injury (AHI) is associated with poor prognosis in sepsis patient; however, to date, no specific therapeutic approach has been established for this disease. Therefore, we aimed to explore the effects and action mechanisms of Astragaloside IV (AS) on AHI. C57BL/6 mice, RAW264.7 cells, and bone marrow-derived macrophages were used in this study. Sepsis-associated AHI model mice were established using lipopolysaccharide + D-galactosamine. Pathological examination of liver tissues and serum alanine aminotransferase/aspartate aminotransferase was performed to evaluate the liver function. Moreover, inflammatory cytokine levels, proportion of M1/M2 macrophages and their marker levels, and cell pyroptosis-related indicator levels were determined in the liver of the AHI model mice with or without AS treatment. AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) expression was determined after AS treatment. Additionally, inflammatory cytokine levels, liver injury, and macrophage polarization were evaluated after inhibiting the AMPK/SIRT1 pathway. AS alleviated lipopolysaccharide + D-galactosamine-induced AHI and inhibited inflammatory reactions in the blood and liver of mice. AS also promoted the M1-to-M2 phenotypic transformation of macrophages in the liver of AHI model mice and invitro, thereby decreasing the pro-inflammatory cytokine levels and increasing the anti-inflammatory cytokine levels. AS increased AMPK and SIRT1 levels in the liver and macrophages. Furthermore, AS improved liver injury by elevating the expression of the AMPK/SIRT1 signaling pathway and inhibiting pyroptosis in macrophages. Overall, AS alleviated AHI by promoting M1-to-M2 macrophage transformation and inhibiting macrophage pyroptosis via activation of the AMPK/SIRT1 signaling pathway.

Characterization of tea polysaccharides from Tieguanyin oolong tea and their hepatoprotective effects via AMP-activated protein kinase-mediated signaling pathways.

In the present study, we succeeded in extracting tea polysaccharide (TPS) from Tieguanyin oolong tea, and the TPS was characterized. TPS is an acidic heteropolysaccharide containing rhamnose, arabinose, galactose, glucose (Glc), xylose, mannose, galacturonic acid, and guluronic acid. We found that TPS supplementation partially reversed the elevated levels of serum alanine aminotransferase, total cholesterol, and low-density lipoprotein cholesterol in high-fat diet (HD)-induced nonalcoholic fatty liver disease (NAFLD) mice (p<0.05), and hepatic steatosis and impaired Glc tolerance were also ameliorated. After HD intervention, the activity of Adenosine 5'-monophosphate-activated protein kinase (AMPK) and its downstream genes, including Sirtuin 1 (SIRT1), sterol regulatory element-binding protein-1c (SREBP1c), acetyl-coenzyme A carboxylase 1 (ACC1), and adipose triglyceride lipase (ATGL), was significantly inhibited (p<0.05). TPS can increase the expression of these genes. The hepatoprotective effects of TPS in AMPK-/- mice almost completely disappeared. Moreover, the expression levels of SIRT1, SREBP1c, ACC1, and ATGL did not significantly change after TPS supplementation (p>0.05). Therefore, our findings suggest that TPS protects the liver from hepatic glucolipid metabolism disorders in HD-induced NAFLD mice by activating AMPK-mediated signaling pathways.

Circ-TTC17 Promotes Esophagus Squamous Cell Carcinoma Cell Growth, Metastasis, and Inhibits Autophagy-Mediated Radiosensitivity Through miR-145-5p/SIRT1 Axis.

Circular RNA (circRNA) plays a significant role in esophagus squamous cell carcinoma (ESCC) progression. Nevertheless, circ-TTC17 roles in ESCC have not fully understood. The levels of circ-TTC17, miR-145-5p and sirtuin 1 (SIRT1) were determined using qRT-PCR. ESCC cell functions were examined by CCK8 assay, flow cytometry, transwell assay and colony formation assay. The relative protein levels of autophagy marker and SIRT1 were determined by western blot (WB). The interactions among circ-TTC17, miR-145-5p, and SIRT1 were verified by dual-luciferase reporter assay and RIP assay. circ-TTC17 was overexpressed and miR-145-5p was underexpressed in ESCC. circ-TTC17 knockdown restrained ESCC cell proliferation and metastasis, while enhance apoptosis and autophagy-mediated radiosensitivity. Circ-TTC17 could sponge miR-145-5p, and its inhibitor reversed the inhibitory effect of circ-TTC17 knockdown on ESCC cell progression. Additionally, SIRT1 was targeted by miR-145-5p, and SIRT1 overexpression abolished miR-145-5p-mediated the suppressive effect on ESCC cell progression. Also, circ-TTC17 interference reduced ESCC tumor growth via miR-145-5p/SIRT1 axis. circ-TTC17 promoted ESCC cell growth, metastasis and inhibited autophagy-mediated radiosensitivity by miR-145-5p/SIRT1 axis.

2-hydroxy-3-methyl anthraquinone promotes apoptosis and inhibits invasion of human hepatocellular carcinoma cells by targeting nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-1/cellular tumor antigen p53 signaling pathway.

To investigate the anti-liver cancer effect of 2-hydroxy-3-methyl anthraquinone (HMA) and the specific mechanism based on nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-1 (SIRT1)/cellular tumor antigen p53 (p53) pathway. Cell counting kit-8 method was used to observe the effect of HMA on the activity of human hepatocellular carcinoma cells (HepG2) cells. At 72 h and 80 μL HMA, the apoptosis rate of HepG2 cells in each group was measured by flow cytometry. Transwell was used to assay for cell invasion. The protein expression levels of SIRT1, p53, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), caspase-9 (CASP9) and caspase-3 (CASP3) were detected by Western Blot. HMA significantly inhibited the proliferation of HepG2 cells, The half inhibiting concentration (IC50) of the HMA at 24, 48 and 72 h were examined and it were 126.3, 98.6, and 80.55 μM, respectively. Compared with the control group, the apoptosis rate of HMA, Selisistat (EX527), and HMA+ EX527 groups enhanced, while the apoptosis rate of SRT1720 diminished, demonstrating that inhibition of SIRT1 can lead to apoptosis of HepG2 cells. HMA+ EX527 group had the highest apoptosis rate, the lowest expression of SIRT1 and Bcl-2, and the highest expression of p53, Bax, CASP9 and CASP3. The number of invasions of HepG2 was significantly reduced after HMA and EX527 intervened. Western blot shows HMA could inhibit SIRT1, promote the expression of p53, and decrease the ratio of Bcl-2/Bax. HMA induced apoptosis in HepG2 cells, while inhibiting proliferation and invasion. The mechanism of HMA against HCC may be related to the SIRT1/p53 pathway.

Nicotinamide Riboside Ameliorates Fructose-Induced Lipid Metabolism Disorders in Mice by Activating Browning of WAT, and May Be Also Related to the Regulation of Gut Microbiota.

This study aims to observe the preventive effect of nicotinamide riboside (NR) on fructose-induced lipid metabolism disorders and explore its mechanism. Male C57BL/6J mice were fed a 20% fructose solution and given 400 mg/kg NR daily by gavage for 10 weeks. The results indicated that NR supplementation significantly reduced the body weight, liver weight, white adipose tissue (WAT) weight, serum, and hepatic lipid levels. NR upregulated the protein expression levels of sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), PR domain containing 16 (PRDM16), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor-gamma coactiva-tor-1-alpha (PGC-1α), nuclear respiratory factor 1-encoding gene (NRF1), mitochondrial transcription factor A (TFAM), cluster of differentiation 137 (CD137), transmembrane protein 26 (TMEM26), and T-box 1 (TBX1). Moreover, NR enhanced the Actinobacteria and Enterorhabdus abundance. Spearman's correlation analysis revealed that significant correlations exist between Firmicutes, Bacteroidetes, and Erysipelotrichaceae with browning-related indicators. In conclusion, NR could alleviate lipid metabolic abnormalities induced by fructose through activating SIRT1/AMPK-mediated browning of WAT. The mechanism by which NR improves fructose-induced lipid metabolism disorders may also be associated with the modulation of intestinal flora.

Antioxidant Effect of a Plant-Derived Extracellular Vesicles' Mix on Human Skin Fibroblasts: Induction of a Reparative Process.

Plant-Derived Extracellular Vesicles extracellular vesicles (PDEVs) from organic agriculture (without the use of pesticides and microbicides) contain high levels of antioxidants. Organic PDEVs have shown an increased antioxidant power compared to PDEVs from single plants, suggesting a synergistic effect of the bioactives constitutively expressed in the PDEVs from single fruits. With this study, we wanted to investigate the beneficial effects of a mix of PDEVs on human skin cells. We found detectable levels of citric acid, ascorbic acid, glutathione, catalase, and SOD in a mix of PDEVs deriving from five different fruits (grape, red orange, papaya, pomegranate, and tangerine). We then treated H2O2-conditioned fibroblasts with the mix of PDEVs. The results showed that the PDEVs' mixture reverted the H2O2-induced redox imbalance, restoring mitochondrial homeostasis, with a strong reduction of mitochondrial anion superoxide and an increase in sirtuin levels. The antioxidant action was consistent with wound repair on a lesion produced in a fibroblast's monolayer. This result was consistent with an increased level of vimentin and matrix metalloproteinase-9, whose expression is directly related to the efficiency of the reparative processes. These data support a beneficial role of PDEVs in both preventing and treating skin injuries through their potent antioxidant and reparative activities.

Evaluation of sirtuin 1 as a predictor of cardiovascular outcomes in diabetic patients with limb-threatening ischemia.

Chronic limb-threatening ischemia (CLTI) significantly increases the risk of major adverse limb events (MALE) and major adverse cardiac events (MACE) after lower extremity revascularization (LER). This study aims to identify novel biomarkers that help to further reduce the risk of postoperative cardiovascular complications. In this prospective, nonrandomized, observational study, baseline serum levels of sirtuin 1 (SIRT1) were assessed in 147 diabetic patients scheduled for LER due to CLTI, and participants were followed for the occurrence of MALE and MACE over 12 months. Fifty-three patients experienced MALE, and 33 experienced MACE within the follow-up period. Lower baseline SIRT1 levels were significantly associated with an increased risk of MALE and MACE, independent of other risk factors. The ROC curve analysis identified a SIRT1 cutoff of 3.79 ng/mL for predicting the risk of MALE. Moreover, incorporating SIRT1 into predictive models significantly enhanced the accuracy of predicting adverse outcomes. Results suggest serum SIRT1 is a potential independent marker for predicting MALE and MACE in diabetic patients with CLTI undergoing LER. Further research is needed to clarify the mechanistic pathways in which SIRT1 may influence cardiovascular outcomes, and the role of this novel biomarker in the management of PAD and CLTI among patients with diabetes.

Pathophysiology of vascular ageing and the effect of novel cardio-renal protective medications in preventing progression of chronic kidney disease in people living with diabetes.

Among people with diabetes those with chronic kidney disease (CKD) have a reduced life expectancy with increased risk of cardiovascular disease (CVD) a major contributor to morbidity and mortality. CKD related to diabetes is growing worldwide and is one of the leading causes of kidney failure globally. Diabetes is associated with accelerated vascular ageing and the related mechanisms and mediators that drive the progression of CKD and CVD disease in people with diabetes may help provide insights into the pathophysiology of cardio-renal complications and guide treatment interventions in people with diabetes. We conducted a narrative review of the literature using PubMed for English language articles that contained keywords that related to diabetes, chronic or diabetic kidney disease, ageing, cellular senescence, arterial stiffness, Klotho and sirtuins, sodium-glucose co-transporter-2 (SGLT-2) inhibitors, renin angiotensin aldosterone system (RAAS) and glucagon-like peptide-1 (GLP-1) receptor agonists. Progressive kidney disease in diabetes is associated with accelerated ageing driven in part by multiple processes such as cellular senescence, inflammation, oxidative stress and circulating uremic toxins. This accelerated ageing phenotype contributes to increased arterial stiffness, endothelial dysfunction, cognitive decline and muscle wasting, thereby elevating morbidity and mortality in individuals with diabetes and CKD. Deficiency of the kidney-derived anti-ageing hormone Klotho and reduced sirtuin levels play pivotal roles in these ageing pathways. Dietary, lifestyle and pharmacological interventions targeting vascular ageing may help reduce the progression of CKD and associated CVD in people with diabetes. The current standard of care and pillars of treatment for kidney disease such as RAAS inhibitors, SGLT-2 inhibitors and GLP-1 receptor agonists all influence pathways involved in vascular ageing. A multifactorial intervention to prevent the development of CKD by targeting traditional risk factors as well as treatment with novel agents with cardio-renal beneficial effects can prevent accelerated ageing and extend lifespan in people with diabetes.

Correlation Between Serum and Tissue SIRT1 Levels in Patients With Esophageal Squamous Cell Carcinoma.

Identifying prognostic and molecular markers as therapeutic targets for esophageal squamous cell carcinoma (ESCC) could enhance the efficacy of multidisciplinary treatments. While tissue expression of sirtuin 1 (SIRT1) has been linked to tumor progression in ESCC, prognostic significance of serum SIRT1 levels and their correlation with tissue SIRT1 remains unexplored. This study aimed to investigate the correlation between serum and tissue SIRT1 levels in patients with ESCC. A total of 38 patients diagnosed with ESCC who were untreated preoperatively were recruited for this study. SIRT1 expression in the surgical specimens was assessed through immunostaining, while serum SIRT1 levels were measured using an enzyme-linked immunosorbent assay. We analyzed the association between tissue and serum SIRT1 levels, clinicopathological features, and patient prognosis. Positive SIRT1 expression in tissue was significantly associated with deeper tumor depth (p=0.020). It was also significantly associated with poorer overall survival (OS) and relapse-free survival (RFS) (p=0.041 and p=0.012, respectively). Elevated serum SIRT1 levels were significantly correlated with increased tumor depth and weight loss (p=0.012 and p=0.030). While higher serum SIRT1 levels tended to be associated with poorer OS (p=0.069), no significant correlation was found between SIRT1 expression in tissue and its concentration in serum. SIRT1 tissue expression may be a valuable prognostic marker in ESCC. However, the clinical significance of serum SIRT1 levels appears to differ from that of its tissue expression. Future research is required to clarify the role of serum SIRT1 in ESCC.

The renoprotective effect of Tibolone in sepsis-induced acute kidney injury.

Sepsis-induced acute kidney injury (AKI) remains a major challenge in intensive care, contributing significantly to morbidity and mortality. Tibolone, known for its neuroprotective and hormonal properties, has not been explored for its potential in AKI management. This study investigates the protective effects of Tibolone and its underlying mechanisms involving Sirtuin-1 (SIRT1) and Yes-Associated Protein (YAP) in a rat sepsis model. Thirty-six female Wistar albino rats underwent cecal ligation and puncture (CLP) to induce sepsis. They were randomly assigned to control, CLP+Saline, and CLP+Tibolone groups. Tibolone was administered intraperitoneally. Biomarkers, including Sirtuin (SIRT1), Yes-associated protein (YAP), Tumor necrosis factor (TNF-α), High mobility group box 1 (HMGB1), malondialdehyde (MDA), creatinine, and urea, were assessed. Histopathological examination evaluated renal damage. Tibolone administration significantly reduced plasma TNF-α, HMGB1, MDA, creatinine, and urea levels compared to the CLP+Saline group. Moreover, Tibolone elevated SIRT1 and YAP levels in kidney tissues. Histopathological examination demonstrated a significant decrease in tubular epithelial necrosis, luminal debris, dilatation, hemorrhage, and interstitial inflammation in Tibolone-treated rats. This study unveils the protective role of Tibolone against sepsis-induced AKI in rats. The improvements in inflammatory and oxidative biomarkers and histological evidence suggest Tibolone's potential as a therapeutic intervention in sepsis-associated kidney injury. The upregulation of SIRT1 and YAP indicates their involvement in Tibolone's renoprotective mechanisms. Further investigations are warranted to explore Tibolone's translational potential in human sepsis-induced AKI.

M7G-modified mt-tRF3b-LeuTAA regulates mitophagy and metabolic reprogramming via SUMOylation of SIRT3 in chondrocytes

N7-methylguanosine (m7G) modification is one of the most prevalent RNA modifications, and methyltransferase-like protein-1 (METTL1) is a key component of the m7G methyltransferase complex. METTL1-catalyzed m7G as a new RNA modification pathway that regulates RNA structure, biogenesis, and cell migration. Increasing evidence indicates that m7G modification has been implicated in the pathophysiological process of osteoarthritis (OA). However, the underlying molecular mechanisms of m7G modification remains incompletely elucidated during the progression of OA. Here we found that METTL1 and m7G levels were markedly increased in OA chondrocytes. In addition, METTL1-mediated m7G modification upregulated mt-tRF3b-LeuTAA expression to exacerbate chondrocyte degeneration. Mechanistically, mt-tRF3b-LeuTAA decreased the SUMO-specific protease 1 (SENP1) protein expression and upregulated the level of sirtuin 3 (SIRT3) SUMOylation to inhibit PTEN induced kinase 1 (PINK1)/Parkin-mediated mitochondrial mitophagy. Intra-articular injection of PMC-tRF3b-LeuTAA inhibitor (Polyamidoamine-polyethylene glycol surface-modified with Minimal self-peptides and Chondrocyte-affinity peptides, PMC) attenuated destabilization of the medial meniscus (DMM) mouse cartilage degeneration in vivo. Our study demonstrates that METTL1/m7G/mt-tRF3b-LeuTAA axis accelerate cartilage degradation by inhibiting mitophagy and promoting mitochondrial dysfunction through SIRT3 SUMOylation, and suggest that targeting METTL1 and its downstream signaling axis could be a promising therapeutic target for OA treatment.

Luteolin Protects against Vascular Calcification by Modulating SIRT1/CXCR4 Signaling Pathway and Promoting Autophagy.

Vascular calcification (VC) is a common pathological manifestation of atherosclerosis, hypertension, diabetes vascular disease, vascular injury, chronic kidney disease and aging, which is mainly manifested as increased stiffness of the vascular wall. Oxidative stress and autophagy dysfunction are key factors in the pathogenesis of vascular calcification, but the specific mechanisms and the therapeutic strategy of vascular calcification have not been clarified. In the present study, Sirtuin 1 (SIRT1) was screened as the therapeutic targets for vascular calcification by the bioinformatics. SIRT1 is a nicotinamide adenine dinucleotide, which plays an important role in inhibiting oxidative stress and promoting autophagy. Luteolin(LUT), a kind of natural tetrahydroxyl flavonoid, exists in many plants and has many pharmacological effects such as anti-oxidation and anti-apoptosis. We have reported that luteolin has certain anti-osteoporosis effects in the previous study, and it is accepted that the development of vascular calcification is similar to bone formation, indicating that luteolin may also resist vascular calcification. And luteolin is known to activate SIRT1 to some extent. Moreover, the molecular docking analysis predicted that SIRT1 could bind directly to luteolin. Therefore, the purpose of this study was to investigate the potential role of luteolin in inhibiting oxidative stress and promoting autophagy during vascular calcification via modulating SIRT1 expression. The results showed that luteolin significantly improved vascular calcification induced by a high-fat diet (HFD) and vitamin D3 in rats in vivo. In addition, luteolin significantly repressed the formation of mineralized nodules and ALP activity in H2O2-treated A7r5 cells. Luteolin reduced the level of MDA, LDH and ROS generation, inhibited the protein expression of cleaved caspase-3, cleaved caspase-9, β-catenin and BMP-2 in the aortic tissue of the rat and rat smooth muscle cells (A7r5) treated with hydrogen peroxide. At the same time, luteolin could promote the expression of autophagy related proteins. Moreover, luteolin also produced effects to increase the protein expression levels of SIRT1 more than 2 times both in vivo and in vitro. In terms of mechanism, luteolin attenuated vascular calcification by inhibiting oxidative stress and improving autophagy level, via modulating SIRT1 / CXCR4 signaling pathway. In conclusion, this experiment for the first time revealed that LUT protected against VC via modulating SIRT1 / CXCR4 signaling pathway to promote autophagy and inhibit vascular calcification and may be developed as a new therapeutic agent for vascular calcification and atherosclerosis.

USP26 Combats Age-Related Declines in Self-Renewal and Multipotent Differentiation of BMSC by Maintaining Mitochondrial Homeostasis.

Age-related declines in self-renewal and multipotency of bone marrow mesenchymal stem cells (BMSCs) limit their applications in tissue engineering and clinical therapy. Thus, understanding the mechanisms behind BMSC senescence is crucial for maintaining the rejuvenation and multipotent differentiation capabilities of BMSCs. This study reveals that impaired USP26 expression in BMSCs leads to mitochondrial dysfunction, ultimately resulting in aging and age-related declines in the self-renewal and multipotency of BMSCs. Specifically, decreased USP26 expression results in decreased protein levels of Sirtuin 2 due to its ubiquitination degradation, which leads to mitochondrial dysfunction in BMSCs and ultimately resulting in aging and age-related declines in self-renewal and multilineage differentiation potentials. Additionally, decreased USP26 expression in aging BMSCs is a result of dampened hypoxia-inducible factor 1α (HIF-1α) expression. HIF-1α facilitates USP26 transcriptional expression by increasing USP26 promoter activity through binding to the -191 - -198 bp and -262 - -269 bp regions on the USP26 promoter. Therefore, the identification of USP26 as being correlated with aging and age-related declines in self-renewal and multipotency of BMSCs, along with understanding its expression and action mechanisms, suggests that USP26 represents a novel therapeutic target for combating aging and age-related declines in the self-renewal and multipotent differentiation of BMSCs.