SIRT1 Protein Levels Research Articles

The Expression of SIRT3 in Endometrial Carcinoma and Its Effect on Promoting Apoptosis of Ishikawa Cells.

Endometrial cancer (EC) is one of the three most common malignancies of the female reproductive system. SIRT3 is an NAD+-dependent protein deacetylase that maintains the stability of the intracellular environment. This study aims to investigate the mechanism of SIRT3 in regulating apoptosis in endometrial cancer and further reveal the role of SIRT3 in endometrial cancer. Differential expression of SIRT3 in tumors was analyzed by GEPIA using TCGA database data. Meanwhile, mRNA and protein expression levels of SIRT3 in tissues and cells were examined using RT-qPCR, Western Blot, and immunohistochemistry. The expression of SIRT3 after estradiol (E2) stimulation of Ishikawa cells was detected using RT-qPCR and Western Blot techniques. The effect of transfection after SIRT3 knockdown and overexpression was verified using RT-qPCR and Western Blot. Flow cytometry and TUNEL assay were used to detect the effect of SIRT3 on apoptosis. Reactive oxygen species (ROS) was used to detect the effect of SIRT3 on the level of oxidative stress in cells. The expression of apoptotic protein (BAX, cleaved-Caspase 3) and autophagy protein (cyto C and LC3A) were detected in transfected Ishikawa cell. Differences analysis of TCGA database data showed that the expression of SIRT3 in EC was significantly lower than that in normal endometrial tissue. The mRNA and protein levels of SIRT3 were significantly lower in EC tissues or cells than normal controls. E2 stimulation in Ishikawa cells resulted in the down-regulation of SIRT3 expression. After transfection, SIRT3 promoted the apoptosis of Ishikawa cells and attenuated the levels of ROS. Overexpression of SIRT3 promoted apoptosis and autophagy-related proteins. Thus, high expression of SIRT3 inhibits the development of EC whereas low expression of SIRT3 may promote the progression of EC, which provides a new direction for studying the treatment of EC.

MiR-204-5p regulates SIRT1 to promote the endoplasmic reticulum stress-induced apoptosis of inner ear cells in C57BL/6 mice with hearing loss.

This study investigated the effect of miR-204-5p-mediated silencing of SIRT1 on the development of deafness in C57BL/6 mice and the roles of miR-204-5p and SIRT1 in deafness. Auditory brainstem response recordings, H&E staining, and immunohistochemistry were used to observe changes in hearing function and cochlear tissue morphology in 2-month-old and 15-month-old C57BL/6 mice. A senescence model was induced using H2O2 in inner ear cells (HEI-OC1). Changes in HEI-OC1 cell proliferation were detected using the CCK-8 assay, whereas flow cytometry was used to detect changes in apoptosis. MiR-204-5p expression was measured via RT‒qPCR. The SIRT1 agonist RSV and a miR-204-5p inhibitor were used to study changes in ER stress (ERS), proliferation, and apoptosis in HEI-OC1 cells. Western blotting was performed to detect changes in ATF4, CHOP, SIRT1, PERK, p-PERK, Bax, and Bcl-2 protein levels. A dual-luciferase reporter gene assay was carried out to assess the ability of miR-204-5p to target SIRT1. Relative miR-204-5p expression levels in the cochleae of aged C57BL/6 mice increased, whereas SIRT1 expression levels decreased, and miR-204-5p and SIRT1 expression levels were negatively correlated. ERS and increased 8-OHDG levels were observed in aged C57BL/6 mice. In a model of inner ear cell aging, H2O2 treatment induced increases in miR-204-5p expression and ERS-mediated apoptosis. MiR-204-5p was found to target SIRT1 and inhibit its expression. SIRT1 activation and a miR-204-5p inhibitor promoted HEI-OC1 cell proliferation and reduced apoptosis. The miR-204-5p inhibitor regulated expression of the ERS proteins PERK, ATF4, and CHOP to upregulate Bcl-2 and downregulate Bax. This study identified the roles of miR-204-5p and SIRT1 in deafness in C57BL/6 mice and investigated the loss of cochlear outer hair cells and the involvement of apoptosis and ERS in deafness.

Intranasal AdipoRon Mitigated Anxiety and Depression-Like Behaviors in 6-OHDA-Induced Parkinson 's Disease Rat Model: Going Beyond Motor Symptoms.

Depression and anxiety are prevalent neuropsychiatric conditions among patients with Parkinson's disease (PD), which may manifest prior to motor symptoms. As levodopa, a prominent treatment for PD motor symptoms, provides few benefits for mood-related abnormalities, tackling non-motor symptoms is particularly important. AdipoRon (Ad), an adiponectin agonist, has demonstrated neuroprotective effects by suppressing neuroinflammatory responses and activating the AMPK/Sirt-1 signaling pathway. This study looked at the potential advantages and underlying mechanisms of intranasal Ad in a rat model of PD induced by 6-hydroxydopamine (6-OHDA). We found that Ad at doses of 1 and 10µg for 21 days exhibited anxiolytic- and antidepressant effects in the open field (OF) test, elevated plus maze (EPM), sucrose splash test, and forced swimming test in a PD model caused by a unilateral 6-OHDA injection into the medial forebrain bundle (MFB). The Ad also lowered the levels of corticosterone in the blood, decreased inflammasome components (NLRP3, caspase 1, and IL-1β), and increased Sirt-1 protein levels in the prefrontal cortex (PFC) of PD rats. We conclude that Ad ameliorates anxious and depressive-like behaviors in the PD rat model through stimulating the AMPK/Sirt-1 signaling and blocking the NLRP3 inflammasome pathways in the PFC.

Caffeine improves systemic lupus erythematosus endothelial dysfunction by promoting endothelial progenitor cells survival.

We studied the role of caffeine intake on endothelial function in SLE by assessing its effect on circulating endothelial progenitor cells (EPCs) both ex vivo in SLE patients and in vitro in healthy donors (HD) treated with SLE sera. We enrolled SLE patients without traditional cardiovascular risks factors. Caffeine intake was evaluated with a 7-day food frequency questionnaire. EPCs percentage was assessed by flow cytometry analysis and, subsequently, EPCs pooled from six HD were co-cultured with caffeine with and without SLE sera. After 7 days, we evaluated cells' morphology and ability to form colonies, the percentage of apoptotic cells by flow cytometry analysis and the levels of autophagy and apoptotic markers by western blot. Finally, we performed a western blot analysis to assess the A2AR/SIRT3/AMPK pathway. We enrolled 31 SLE patients, and observed a positive correlation between caffeine intake and circulating EPCs percentage. HD EPCs treated with SLE sera and caffeine showed an improvement in morphology and in number of EPCs colony-forming units in comparison with those incubated without caffeine. Caffeine was able to restore autophagy and apoptotic markers in HD EPCs as before SLE sera treatment. Finally, caffeine treatment was able to significantly reduce A2AR levels, leading to an increase in protein levels of SIRT3 and subsequently AMPK phosphorylation. Caffeine intake positively correlated with the percentage of circulating EPCs in SLE patients; moreover, caffeine in vitro treatment was able to improve EPC survival and vitality through the inhibition of apoptosis and the promotion of autophagy via A2AR/SIRT3/AMPK pathway.

Melinjo (Gnetum gnemon L) Extract Attenuates Colonic Inflammation in a Mouse Colitis Model by Regulating the AMPK/NFκB/Sirt1 Pathway.

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease affecting the colon with idiopathic origin. Melinjo endosperm extract (MeE) contains polyphenolic compounds that have antioxidative and anticancer properties. We examined the effect of MeE on inflammation and mucin expression in the colons of UC of mice treated with dextran sulfate sodium (DSS). C57BL/6J male mice were assigned into four categories: control, DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE. The control group was provided distilled water and a standard chow diet for 4 weeks. In DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE groups, the mice were treated with MeE for 3 weeks followed by MeE diets and drinking water containing 3% DSS for a week. Macrophage count, the mucus area stained by Alcian blue (AB), the levels of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor-κB (NFκB) p65, and silent information regulator (Sirt) 1 protein expression, as well as proinflammatory mediators and Mucin 2 mRNA expression were assessed. In the DSS + 0% MeE group, the AB-stained areas and Mucin 2 mRNA expression levels were observed to be lower than those of controls. However, the levels in the +0.5% MeE group were significantly increased. Compared with the control group, the macrophage number, the expression of IL-1β mRNA, and NFκB p65 protein in the DSS + 0% MeE group showed a significant increase. Conversely, these levels were significantly decreased in the +0.5% MeE group. The phosphorylated AMPK and Sirt1 protein levels were upregulated in the +0.5% MeE group. In conclusion, MeE may alleviate UC injury by reducing macrophage infiltration and regulating the AMPK/NFκB/Sirt1 pathway.

Loss of NAMPT and SIRT2 but not SIRT1 attenuate GLO1 expression and activity in human skeletal muscle

Glyoxalase I (GLO1) is the primary enzyme for detoxification of the reactive dicarbonyl methylglyoxal (MG). Loss of GLO1 promotes accumulation of MG resulting in a recapitulation of diabetic phenotypes. We previously demonstrated attenuated GLO1 protein in skeletal muscle from individuals with type 2 diabetes (T2D). However, whether GLO1 attenuation occurs prior to T2D and the mechanisms regulating GLO1 abundance in skeletal muscle are unknown. GLO1 expression and activity were determined in skeletal muscle tissue biopsies from 15 lean healthy individuals (LH, BMI: 22.4 ± 0.7) and 5 individuals with obesity (OB, BMI: 32.4 ± 1.3). GLO1 protein was attenuated by 26 ± 0.3 % in OB compared to LH skeletal muscle (p = 0.019). Similar reductions for GLO1 activity were observed (p = 0.102). NRF2 and Keap1 expression were equivocal between groups despite a 2-fold elevation in GLO1 transcripts in OB skeletal muscle (p = 0.008). GLO1 knock-down (KD) in human immortalized myotubes promoted downregulation of muscle contraction and organization proteins indicating the importance of GLO1 expression for skeletal muscle function. SIRT1 KD had no effect on GLO1 protein or activity whereas, SIRT2 KD attenuated GLO1 protein by 28 ± 0.29 % (p < 0.0001) and GLO1 activity by 42 ± 0.12 % (p = 0.0150). KD of NAMPT also resulted in attenuation of GLO1 protein (28 ± 0.069 %, p = 0.003), activity (67 ± 0.09 %, p = 0.011) and transcripts (50 ± 0.13 %, p = 0.049). Neither the provision of the NAD+ precursors NR nor NMN were able to prevent this attenuation in GLO1 protein. However, NR did augment GLO1 specific activity (p = 0.022 vs NAMPT KD). These perturbations did not alter GLO1 acetylation status. SIRT1, SIRT2 and NAMPT protein levels were all equivocal in skeletal muscle tissue biopsies from individuals with obesity and lean individuals. These data implicate NAD+-dependent regulation of GLO1 in skeletal muscle independent of altered GLO1 acetylation and provide rationale for exploring NR supplementation to rescue attenuated GLO1 abundance and activity in conditions such as obesity.

Hesperidin Alleviates Acute Necrotizing Pancreatitis by Activating SIRT1 - Molecular Docking, Molecular Dynamics Simulation, and Experimental Validation.

Acute necrotizing pancreatitis is a serious pancreatic injury with limited effective treatments. This study aims to investigate the therapeutic effects of hesperidin on Larginine- induced acute pancreatitis and its potential targets. The authors induced acute pancreatitis in mice by administering two hourly intraperitoneal injections of L-arginine-HCl, and evaluated the impact of hesperidin on pancreatic and lung tissues, plasma amylase activity, and myeloperoxidase content. Additionally, necrosis and mitochondrial function was tested in primary pancreatic acinar cells. The interactions between hesperidin and proteins involved in necrosis and mitochondrial dysfunction were further invested using in silico molecular docking and molecular dynamic simulations. Hesperidin effectively ameliorated the severity of acute necrotizing pancreatitis by reducing plasma amylase, pancreatic MPO, serum IL-6 levels, pancreatic edema, inflammation, and pancreatic necrosis. Hesperidin also protected against acute pancreatitis-associated lung injury and prevented acinar cell necrosis, mitochondrial membrane potential loss, and ATP depletion. In addition, hesperidin exhibited a high binding affinity with SIRT1 and increased the protein levels of SIRT1. The SIRT1 inhibitor EX527 abolished the protective effect of hesperidin against necrosis in acinar cells. These findings indicate that hesperidin alleviates the severity of acute necrotizing pancreatitis by activating SIRT1, which may provide insight into the mechanisms of natural compounds in treating AP. Hesperidin has potential as a therapeutic agent for acute necrotizing pancreatitis and provides a new approach for novel therapeutic strategies.

Baicalin promotes migration and angiogenesis of endothelial progenitor cells but impedes thrombus formation via SIRT1/NF-κB signaling in a rat model of deep vein thrombosis.

Deep vein thrombosis (DVT) is the third most prevalent vascular disease worldwide, seriously threatening human health. Baicalin, a flavonoid isolated from the roots of Scutellaria baicalensis, has been identified to play a crucial role in various vascular diseases. The study aimed to explore the efficacy and underlying mechanisms of baicalin in DVT. Endothelial progenitor cells (EPCs) were differentiated from peripheral blood mononuclear cells isolated from rat bone marrow. Dil-ac-LDL/FITC-UEA-1 double staining and flow cytometry analysis were conducted for the identification of EPCs. The angiogenesis and migration of EPCs in vitro were tested by a tube formation assay and Transwell assay, respectively. DVT rat models were established by stenosis of the inferior vena cava (IVC). After the euthanasia of rats, thrombi in the IVC were collected and weighed, and histological alterations in IVC tissue were measured by H&E staining. The protein levels of SIRT1, p-P65, and p65 in rat IVC tissues were quantified via western blotting. EPCs used in this study displayed a spindle-like shape and were positive for endothelial cell-specific markers, suggesting the phenotypic characteristics of EPCs. Baicalin enhanced the migratory and angiogenetic abilities of EPCs in vitro. For in vivo experiments, baicalin reduced thrombus weight and mitigated DVT formation in model rats. Moreover, baicalin activated SIRT but repressed NF-κB signaling in IVC tissues of DVT rats. Baicalin facilitates migration and angiogenesis of EPCs but impedes thrombus formation via regulation of SIRT1/NF-κB signaling in DVT model rats.

Diethyl phthalate and dibutyl phthalate disrupt sirtuins expression in the HepG2 cells.

Phthalates are additives used as plasticizers among other uses, classified as endocrine disruptors and may contribute to some metabolic disorders. The aim of this work was to determine the effect of the exposure of diethyl phthalate (DEP) and dibutyl phthalate (DBP) on cell viability and reactive oxygen species (ROS) production, as well as the regulation of sirloins in HepG2 cells. HepG2 cells were exposed to DEP or DBP at 0.1, 1, 10 and 100 μg/mL, and after 48 or 72 h the gene and protein expression of sirtuins was quantified by qRT-PCR and Western-Blot, respectively. Results showed that even at a low concentration of 0.1 μg/mL DEP affected the expression of Sirt3 and Sirt4, whereas DBP at 0.1 μg/mL affected Sirt3 and Sirt5 gene expression. Protein analysis showed a reduction in Sirt1 levels at a DEP concentration of 1 μg/mL and higher, while DBP at higher dose (100 μg/mL) decreased Sirt3 protein levels. Cell viability decreased by 20% only at higher dose (100 μg/mL) and ROS production increased at 10 and 100 μg/mL for both phthalates. These findings indicate that exposure to low concentrations (0.1 μg/mL) of DEP or DBP can negatively influence the expression of some sirtuins.

Lycopene alleviates Bisphenol a-induced lipid accumulation via activating the SIRT1/PGC-1α signaling in PK15 cells

The present study sought to investigate the protective effect of Lycopene (LYC) on Bisphenol A (BPA)-induced lipid accumulation and elucidate the potential molecular mechanism. In vitro, the PK15 cells with or without LYC were exposed to BPA for 6 h to detect the lipid accumulation using Nile red’s and Oil Red O’ staining. Meanwhile, redox status, mitochondrial function, gene expression and protein levels relating to lipid accumulation were evaluated by cellular biochemical assays, immunofluorescence staining, quantitative real-time PCR (qRT-PCR) and Western blot, respectively. In addition, ROS scavenger N-acetylcysteine (NAC), SIRT1 inhibitor EX527, SIRT1 siRNA and PGC-1α siRNA were used to verify the target signaling pathways responsible for the protective effect of LYC against BPA-indcued lipid accumulation. In vivo, the twenty four male Wistar rats were randomly divided into three groups, received either BPA (50 mg/kg/day BW) or LYC (10 mg/kg/day BW) orally for 60 days. The kidney tissues were evaluated by HE’s and Oil Red O’s staining, lipid-associated genes and proteins expression were detected through qRT-PCR and Western blot. The results showed that BPA-exposed PK15 cells and rats had increased lipid droplets with elevated transcription of lipogenic factors SREBP1 and PPARγ, and down-regulated PPARα expression, and which is accompanied by redox imbalance and abnormal mitochondrial function. Conversely, LYC prevented BPA-induced lipid metabolism disorder and lipid accumulation through impeding ROS overproduction. Moreover, PK15 cells and rats exposed to BPA showed decrease in SIRT1 and PGC-1α levels, whereas LYC blocked the decrease of SIRT1 and PGC-1α protein levels. Furthermore, inhibition or silence of SIRT1 and PGC-1α abrogated the improvements of LYC on ROS generation, mitochondrial mass impairement and lipid accumulation in BPA-treated PK15 cells. Collectively, these findings indicate that SIRT1/PGC-1α signaling pathway is involved in the protective effect of LYC on BPA-induced lipid accumulation. These results also provide a potential promising therapeutic of LYC against BPA-induced lipid accumulation in kidney cells and organs.

Anti-osteoporosis effect of Prunus humilis fruit on ovariectomized rats via modulating the function of bone metabolism

Prunus humilis Bge. (PH), also known as calcium fruits, is rich in minerals and polyphenols. Given its high content of calcium and other mineral elements, it is believed to be an ideal health fruit to prevent osteoporosis (OP). Hence, the present research aimed to estimate the anti-osteoporotic activity of the fruit of PH in ovariectomized (OVX) rats and to explore the corresponding mechanisms. By utilizing LC-QTOF-MS/MS, 18 primary components, including 14 flavonoids and 4 phospholipids were elucidated in PH. The results of inductively coupled plasma optical emission spectrometry demonstrated that PH exhibited high levels of calcium (1573–1829 mg/kg), phosphorus (1328–1731 mg/kg), and magnesium (897–1027 mg/kg). The pharmacodynamic experiments conducted on OVX rats revealed that continuous oral intervention with PH (10–62.5 mg/kg/day) for three months resulted in significant improvements in both bone mineral density and bone microarchitecture. Meanwhile, the intervention with PH also effectively reversed the bone resorption and formation factors, including type I collagen carboxy-terminal peptide, acid phosphatase 5 tartrate-resistant, deoxypyridinoline, alkaline phosphatase, and procollagen amino-terminal peptide. Additionally, the utilization of LC-QTOF-MS/MS metabolomics revealed the identification of 16 differential metabolites linked to 9 metabolic pathways, all of which were recovered following PH treatment. Furthermore, the protein levels of β-catenin, Wnt1, Sirt1, and FOXO3a were significantly up-regulated after PH intervention, indicating a potential association between the anti-osteoporosis properties of PH and the Wnt/β-catenin and Sirt1/FOXO3a signaling pathways. Our findings provide a new idea for the prevention and treatment of OP through the daily consumption of PH, a sweet and flavorful fruit.

Sex-related differences in SIRT3-mediated mitochondrial dynamics in renal ischemia/reperfusion injury

The prevalence of renal ischemia/reperfusion injury (IRI) in premenopausal women is considerably lower than that in age-matched men. This suggests that sex-related differences in mitochondrial function and homeostasis may contribute to sexual dimorphism in renal injury, though the mechanism remains unclear. Mouse model of unilateral left renal IRI with contralateral kidney enucleation, Ovariectomy in female mice, and a human embryonic kidney (HEK) cell model of hypoxia-reoxygenation were used to study how estrogen affects the sexual dimorphism of renal IRI through SIRT3 in vitro and in vivo, respectively. Here, we demonstrate differential expression of renal SIRT3 may induce sexual dimorphism in IRI using the renal IRI model. Higher SIRT3 level in female mice was associated with E2-induced protection of renal tubular epithelium, reduced mitochondrial reactive oxygen species (ROS), and IRI resistance. In hypoxia-reoxygenated HEK cells, SIRT3 knockdown increased oxidative stress, shifted the interconnected mitochondrial network toward fission, exacerbated hypoxia/reoxygenation-induced endoplasmic reticulum stress (ERS), and abolished the protective effects of E2 on IRI. Mechanistically, the SIRT3 level is E2-dependent and that E2 increases the SIRT3 protein level via estrogen receptor. SIRT3 targeted an i-AAA protease, yeast mitochondrial AAA metalloprotease (YME1L1), and hydrolyzed long optic atrophy 1 (L-OPA) to short-OPA1 (S-OPA1) by deacetylating YME1L1, regulating mitochondrial dynamics toward fusion to reduce oxidative stress and ERS. These findings explored the mechanism by how estrogen alleviates renal IRI and providing a basis for potential therapeutic interventions targeting SIRT3.

A proteasome-dependent inhibition of SIRT-1 by the resveratrol analogue 4,4′-dihydroxy-trans-stilbene

Background and aimResveratrol (RSV), is a stilbene-based compound exerting wide biological properties. Its analogue 4,4′-dihydroxy-trans-stilbene (DHS) has shown improved bioavailability and antiproliferative activity in vitro and in vivo. One of the hypotheses on how resveratrol works is based on SIRT1 activation. Since their strict structural similarities, we have explored a potential interaction between DHS and SIRT1, in comparison with the parental molecule. Experimental procedureTiming of incubation and concentrations of DHS have been determined using MTT assay in normal human lung fibroblasts. Untreated, DHS- or RSV-treated cells were harvested and analysed by Western Blotting or RT-PCR, in order to evaluate SIRT1 levels/activity and expression, and by Cellular Thermal shift assay (CETSA) to check potential DHS or RSV-SIRT1 interaction. Transfection experiments have been performed with two SIRT1 mutants, based on the potential binding pockets identified by Molecular Docking analysis. Results and conclusionWe unexpectedly found that DHS, but not RSV, exerted a time-dependent inhibitory effect on both SIRT1 protein levels and activity, the latter measured as p53 acetylation. At the mRNA level no significant changes were observed, whereas a proteasome-dependent mechanism was highlighted for the reduction of SIRT1 levels by DHS in experiments performed with the proteasome inhibitor MG132. Bioinformatics analysis suggested a higher affinity of RSV in binding all SIRT1 complexes compared to DHS, except comparable results for complex SIRT1-p53. Nevertheless, both CETSA and SIRT1 mutants transfected in cells did not confirm this interaction. In conclusion, DHS reduces SIRT1 protein level, thereby inhibiting its activity through a proteasome-mediated mechanism.

Anthocyanins from Lycium ruthenicum Murray Mitigate Cadmium-Induced Oxidative Stress and Testicular Toxicity by Activating the Keap1/Nrf2 Signaling Pathway.

Cadmium (Cd) is a hazardous heavy metal environmental pollutant that has carcinogenic, teratogenic, and mutagenic properties. Excessive exposure to Cd can induce oxidative stress, which greatly harms the male reproductive system. Anthocyanins have remarkable antioxidative, anti-inflammatory, and anti-stress properties. In this study, we investigated the effects of anthocyanins and the underlying mechanisms through which anthocyanins mitigate Cd-induced reproductive damage. We isolated and purified Lycium ruthenicum Murray anthocyanin extract (LAE) and performed UHPLC-MS/MS to identify 30 different anthocyanins. We established an ICR mouse Cd injury model by administering 5 mg/kg/day CdCl2 for 28 consecutive days. LAE at 500 mg/kg/day effectively ameliorated testicular damage and preserved spermatogenesis. The mice in the LAE-treated group had elevated testosterone and inhibin B levels. Additionally, the treatment restored the activity of antioxidant enzymes, including T-SOD, CAT, and GR, and substantially increased the levels of the non-enzymatic antioxidant GSH. Research findings indicate that LAE can activate the SIRT1/Nrf2/Keap1 antioxidant pathway. This activation is achieved through the upregulation of both the SIRT1 gene and protein levels, leading to the deacetylation of Nrf2. Moreover, LAE reduces the expression of Keap1, alleviating its inhibitory effect on Nrf2. This, in turn, facilitates the uncoupling process, promoting the translocation of Nrf2 to the nucleus, where it governs downstream expression, including that of HO-1 and GPX1. LAE effectively mitigated toxicity to the reproductive system associated with exposure to the heavy metal Cd by alleviating oxidative stress in the testes.

Ameliorative effect of resveratrol on acute ocular hypertension induced retinal injury through the SIRT1/NF-κB pathway

Glaucoma is a kind of neurodegenerative disorder characterized by irreversible loss of retinal ganglion cells (RGCs) and permanent visual impairment. It is reported that resveratrol (RES) is a promising drug for neurodegenerative diseases. However, the detailed molecular mechanisms underlying its protective potential have not yet been fully elucidated. The present study sought to investigate whether resveratrol could protect RGCs and retinal function triggered by acute ocular hypertension injury through the SIRT1/NF-κB pathway. An experimental glaucoma model was generated in C57BL/6J mice. Resveratrol was intraperitoneally injected for 5 days. Sirtinol was injected intravitreally on the day of retinal AOH injury. RGC survival was determined using immunostaining. TUNEL staining was conducted to evaluate retinal cell apoptosis. ERG was used to evaluate visual function. The proteins Brn3a, SIRT1, NF-κB, IL-6, Bax, Bcl2, and Cleaved Caspase3 were determined using western blot. The expression and localisation of SIRT1 and NF-κB in the retina were detected by immunofluorescence. Our data indicated that resveratrol treatment significantly increased Brn3a-labelled RGCs and reduced RGC apoptosis caused by AOH injury. Resveratrol administration also remarkably decreased NF-κB, IL-6, Bax, and Cleaved Caspase3 proteins and increased SIRT1 and Bcl2 proteins. Furthermore, resveratrol treatment obviously inhibited the reduction in ERG caused by AOH injury. Importantly, simultaneous administration of resveratrol and sirtinol abrogated the protective effect of resveratrol, decreased NF-κB protein expression, and increased SIRT1 protein levels. These results suggest that resveratrol administration significantly mitigates retinal AOH-induced RGCs loss and retinal dysfunction, and that this neuroprotective effect is partially regulated through the SIRT1/NF-κB pathway.

ZMIZ1 Regulates Proliferation, Autophagy and Apoptosis of Colon Cancer Cells by Mediating Ubiquitin-Proteasome Degradation of SIRT1.

There are nearly 1.15 million new cases of colon cancer, as well as 586,858 deaths from colon cancer worldwide in 2020. The aim of this study is to reveal whether ZMIZ1 can control the fate of colon cancer cells and the mechanism by which it functions. Specific shRNA transfection was used to knock down the expression of ZMIZ1 in colon cancer cell lines (HCT116 and HT29), and cell proliferation was detected using EdU and CCK-8 reagents, apoptosis by flow cytometry, and autophagy by western blot. The interaction of ZMIZ1 and SIRT1 was analyzed. Knockdown of ZMIZ1 significantly inhibited autophagy and proliferation, and induced apoptosis of HCT116 and HT29 cells. The mRNA level of SIRT1 was not affected by ZMIZ1 knockdown, but the protein level of SIRT1 was significantly decreased and the protein level of the SIRT1-specific substrate, acetylated FOXO3a, was reduced. Immunoprecipitation assays identified the interaction between SIRT1 and ZMIZ1 in HCT116 and HT29 cells. ZMIZ1 increased intracellular ubiquitination of SIRT1. Knockdown or pharmacological inhibition of SIRT1 neutralized the effects of ZMIZ knockdown on proliferation, autophagy and apoptosis in HCT116 and HT29 cells. ZMIZ1 may control the fate of colon cancer cells through the SIRT1/FOXO3a axis. Targeting ZMIZ1 would be beneficial for the treatment of colon cancer.

Diosmin ameliorates renal fibrosis through inhibition of inflammation by regulating SIRT3-mediated NF-κB p65 nuclear translocation

BackgroundRenal fibrosis is considered an irreversible pathological process and the ultimate common pathway for the development of all types of chronic kidney diseases and renal failure. Diosmin is a natural flavonoid glycoside that has antioxidant, anti-inflammatory, and antifibrotic activities. However, whether Diosmin protects kidneys by inhibiting renal fibrosis is unknown. We aimed to investigate the role of Diosmin in renal interstitial fibrosis and to explore the underlying mechanisms.MethodsThe UUO mouse model was established and gavaged with Diosmin (50 mg/kg·d and 100 mg/kg·d) for 14 days. HE staining, Masson staining, immunohistochemistry, western blotting and PCR were used to assess renal tissue injury and fibrosis. Elisa kits were used to detect the expression levels of IL-1β, IL-6, and TNF-α and the activity of SIRT3 in renal tissues. In addition, enrichment maps of RNA sequencing analyzed changes in signaling pathways. In vitro, human renal tubular epithelial cells (HK-2) were stimulated with TGF-β1 and then treated with diosmin (75 μM). The protein and mRNA expression levels of SIRT3 were detected in the cells. In addition, 3-TYP (selective inhibitor of SIRT3) and SIRT3 small interfering RNA (siRNA) were used to reduce SIRT3 levels in HK-2.ResultsDiosmin attenuated UUO-induced renal fibrosis and TGF-β1-induced HK-2 fibrosis. In addition, Diosmin reduced IL-1β, IL-6, and TNF-α levels in kidney tissues and supernatants of HK-2 medium. Interestingly, Diosmin administration increased the enzymatic activity of SIRT3 in UUO kidneys. In addition, Diosmin significantly increased mRNA and protein expression of SIRT3 in vitro and in vivo. Inhibition of SIRT3 expression using 3-TYP or SIRT3 siRNA abolished the anti-inflammatory effects of diosmin in HK-2 cells. Enrichment map analysis by RNA sequencing indicates that the nuclear factor-kappa B (NF-κB) signaling pathway was inhibited in the Diosmin intervention group. Furthermore, we found that TGF-β1 increased the nuclear expression of nuclear NF-κB p65 but had little significant effect on the total intracellular expression of NF-κB p65. Additionally, Diosmin reduced TGF-β1-caused NF-κB p65 nuclear translocation. Knockdown of SIRT3 expression by SIRT3 siRNA increased the nuclear expression of NF-κB p65 and abolished the inhibition effect of Diosmin in NF-κB p65 expression.ConclusionsDiosmin reduces renal inflammation and fibrosis, which is contributed by inhibiting nuclear translocation of NF-κB P65 through activating SIRT3.

Reduced SIRT1 and SIRT3 and Lower Antioxidant Capacity of Seminal Plasma Is Associated with Shorter Sperm Telomere Length in Oligospermic Men.

Infertility affects millions of couples worldwide and has a profound impact not only on their families, but also on communities. Telomere attrition has been associated with infertility, DNA damage and fragmentation. Oxidative stress has been shown to affect sperm DNA integrity and telomere length. Sirtuins such as SIRT1 and SIRT3 are involved in aging and oxidative stress response. The aim of the present study is to determine the role of SIRT1 and SIRT3 in regulating oxidative stress, telomere shortening, and their association with oligospermia. Therefore, we assessed the protein levels of SIRT1 and SIRT3, total antioxidant capacity (TAC), superoxide dismutase (SOD), malondialdehyde (MDA) and catalase activity (CAT) in the seminal plasma of 272 patients with oligospermia and 251 fertile men. We also measured sperm telomere length (STL) and leukocyte telomere length (LTL) using a standard real-time quantitative PCR assay. Sperm chromatin and protamine deficiency were also measured as per standard methods. Our results for oligospermic patients demonstrate significant reductions in semen parameters, shorter STL and LTL, lower levels of SOD, TAC, CAT, SIRT1 and SIRT3 levels, and also significant protamine deficiency and higher levels of MDA and DNA fragmentation. We conclude that a shorter TL in sperms and leukocytes is associated with increased oxidative stress that also accounts for high levels of DNA fragmentation in sperms. Our results support the hypothesis that various sperm parameters in the state of oligospermia are associated with or caused by reduced levels of SIRT1 and SIRT3 proteins.

Downregulation of miR-138-5p alleviates propofol-induced neurotoxicity and autophagy by regulating SIRT1.

Propofol, a commonly utilized anesthetic, has been shown to induce neurotoxicity in developing neurons. A previous study showed that microRNA (miR)-138-5p was dysregulated in hippocampus tissue of mice administrated with propofol. The current study aimed to investigate the functions of miR-138-5p and its target gene in propofol-induced neurotoxicity. SH-SY5Y neuronal cells were treated with increasing doses of propofol for indicated time to identify the optimal concentration and treatment time. MiR-138-5p and SIRT1 expression in SH-SY5Y neuronal cells stimulated with propofol were measured by RT-qPCR. Western blotting was performed to quantify protein levels of SIRT1 and autophagy markers. After interference of miR-138-5p and/or SIRT1 expression, the toxicity of SH-SY5Y neuronal cells was evaluated by cell counting kit-8 (CCK-8) assays and flow cytometry. The formation of autophagosomes was estimated by monodansylcadaverine staining. Propofol induced neurotoxicity in a dose- or time-dependent manner. Propofol upregulated miR-138-5p while downregulating SIRT1 in SH-SY5Y neuronal cells. The propofol-stimulated neurotoxicity and autophagy was inhibited by miR-138-5p knockdown. Moreover, miR-138-5p bound to SIRT1 3'untranslated region. SIRT1 overexpression increased cell viability while inhibiting apoptosis and autophagy in the context of propofol. SIRT1 downregulation reversed the ameliorative effect of miR-138-5p inhibition on propofol-induced neurotoxicity and autophagy. Downregulation of miR-138-5p alleviates propofol-induced neurotoxicity and autophagy via upregulation of SIRT1.

Exploring the mRNA and Plasma Protein Levels of BDNF, NT4, SIRT1, HSP27, and HSP70 in Multiple Sclerosis Patients and Healthy Controls.

Multiple sclerosis (MS) is a chronic, autoimmune neurodegenerative disease affecting the central nervous system. It is a major cause of non-traumatic neurological disability among young adults in North America and Europe. This study focuses on neuroprotective genes (BDNF, NT4/5, SIRT1, HSP70, and HSP27). Gene expression and protein levels of these markers were compared between MS patients and healthy controls. Blood samples were collected from 42 patients with multiple sclerosis (MS) and 48 control subjects without MS. Quantitative real-time PCR was performed to measure the expression of specific genes. The samples were analyzed in duplicate, and the abundance of mRNA was quantified using the 2-ΔCt method. ELISA assay was used to measure the concentration of specific proteins in the plasma samples. The results show that a 3.5-fold decrease in the gene expression of BDNF corresponds to a 1.5-fold downregulation in the associated plasma protein concentration (p < 0.001). Similar trends were observed with NT-4 (five-fold decrease, slight elevation in protein), SIRT1 (two-fold decrease, two-fold protein decrease), HSP70 (four-fold increase, nearly two-fold protein increase), and HSP27 (four-fold increase, two-fold protein increase) (p < 0.001). This study reveals strong correlations between gene expression and protein concentration in MS patients, emphasizing the relevance of these neuroprotective markers in the disease.