Sirtuin 1 Protein Levels Research Articles

Enhanced SIRT1 Activity by Galangin Mitigates UVB-Induced Senescence in Dermal Fibroblasts via p53 Acetylation Regulation and Activation.

Human skin aging, a complex process influenced by intrinsic aging and extrinsic photoaging, is marked by the accumulation of reactive oxygen species (ROS) that cause DNA damage, impaired dermal fibroblast function, and wrinkle formation. External stressors, such as ultraviolet (UV) radiation, can trigger cellular senescence. Sirtuin-1 (SIRT1), an NAD+-dependent enzyme in the sirtuin family, plays a crucial role in deacetylating p53, thereby inhibiting its nuclear translocation and reducing skin senescence. Galangin, a flavonoid found in honey and Alpinia officinarum root, has antioxidant and anti-inflammatory properties. This study investigates the protective mechanism of galangin against UVB-induced senescence in human dermal fibroblasts (HDFs) by examining its effects on SIRT1 and its target, acetylated-p53. An in vitro model of UVB-induced senescence using HDFs and an in vivo model using nude mice were employed to assess the dermal protective effects of galangin. The results demonstrate that while UVB exposure does not decrease SIRT1 protein levels, it impairs its enzymatic function. However, galangin treatment counteracts these adverse effects. Additionally, UVB exposure significantly reduces cell viability and upregulates senescence markers like p16, p21, and p53 nuclear transactivation. An increase in senescence-associated β-galactosidase (SA-β-gal) positive cells was observed in UVB-exposed dermal fibroblasts. Galangin treatment mitigates UVB-induced cellular senescence by enhancing SIRT1-mediated p53 deacetylation, thereby inhibiting nuclear translocation and reducing dermal senescence. These findings suggest that galangin is a promising agent for alleviating UVB-induced skin aging and could be a potential component in antiaging cosmetic formulations.

Shenmai injection improves lipid metabolism in post-myocardial infarction heart failure based on network pharmacology and experimental validation

BackgroundShenmai injection (SMI), a traditional Chinese medicine formulation derived from the herbal decoction Shenmai Yin, is widely used in treating cardiovascular disorders. This study extensively investigated the effects and mechanisms of action of SMI on lipid metabolism in post-myocardial infarction heart failure (pMIHF). MethodsNetwork pharmacology was employed to predict the key targets and associated pathways involved in lipid metabolism for potential SMI treatments in post-myocardial infarction heart failure (pMIHF). Subsequently, a pMIHF mouse model and an ischemia/reperfusion (I/R) cell model were established to delve deeper into and validate the underlying mechanism of action. ResultsWe performed network pharmacology analysis, which identified 48 active components in SMI and 201 common gene targets. Subsequent screening using the protein–protein interaction network identified 26 core targets, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, peroxisome proliferator-activated receptor alpha (PPARα), and sirtuin 1 (SIRT1). Based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, we predicted that SMI might act on lipid metabolism in pMIHF through the PPARα pathway, a hypothesis supported by the strong binding affinity between this receptor and the active components of SMI, as confirmed via molecular docking. In a left anterior descending artery-ligation mouse model, SMI significantly improved cardiac function, reduced serum free fatty acid levels, decreased inflammatory cell infiltration and myocardial fibrosis, and maintained myocardial mitochondrial morphology. In ischemia-reperfusion (I/R) cells, SMI reduced cell apoptosis, improved mitochondrial membrane potential, and decreased mRNA expression levels of IL-6 and TNF-α, while increasing protein levels of PPARα, SIRT1, and PPARα co-activator-1 alpha (PGC1α). ConclusionCollectively, our findings suggest that SMI enhances myocardial lipid metabolism and ameliorates pMIHF by upregulating the PPARα/SIRT1/PGC1α pathway.

SIRT1 Regulates Mitochondrial Damage in N2a Cells Treated with the Prion Protein Fragment 106-126 via PGC-1α-TFAM-Mediated Mitochondrial Biogenesis.

Mitochondrial damage is an early and key marker of neuronal damage in prion diseases. As a process involved in mitochondrial quality control, mitochondrial biogenesis regulates mitochondrial homeostasis in neurons and promotes neuron health by increasing the number of effective mitochondria in the cytoplasm. Sirtuin 1 (SIRT1) is a NAD+-dependent deacetylase that regulates neuronal mitochondrial biogenesis and quality control in neurodegenerative diseases via deacetylation of a variety of substrates. In a cellular model of prion diseases, we found that both SIRT1 protein levels and deacetylase activity decreased, and SIRT1 overexpression and activation significantly ameliorated mitochondrial morphological damage and dysfunction caused by the neurotoxic peptide PrP106-126. Moreover, we found that mitochondrial biogenesis was impaired, and SIRT1 overexpression and activation alleviated PrP106-126-induced impairment of mitochondrial biogenesis in N2a cells. Further studies in PrP106-126-treated N2a cells revealed that SIRT1 regulates mitochondrial biogenesis through the PGC-1α-TFAM pathway. Finally, we showed that resveratrol resolved PrP106-126-induced mitochondrial dysfunction and cell apoptosis by promoting mitochondrial biogenesis through activation of the SIRT1-dependent PGC-1α/TFAM signaling pathway in N2a cells. Taken together, our findings further describe SIRT1 regulation of mitochondrial biogenesis and improve our understanding of mitochondria-related pathogenesis in prion diseases. Our findings support further investigation of SIRT1 as a potential target for therapeutic intervention of prion diseases.

Deacetylation of HnRNP U mediated by sirtuin1 ameliorates aged rat with liver fibrosis via inhibiting p53-related senescence and NLRP3-related inflammation

Senescence represents a major risk factor promoting liver fibrosis progression. Sirtuin 1 (SIRT1), an essential regulator of cellular senescence, may be involved in developing liver fibrosis. However, the role and mechanism of SIRT1 in liver fibrosis development were largely unknown. We constructed the liver fibrosis in aged rats induced by carbon tetrachloride (CCl4) and then transfected with GFP-SIRT1 adenoviral vectors. After that, we performed acetylomic analysis of liver tissue in aged rats to identify potential substrates of SIRT1. Furthermore, replicative senescent rat hepatocytes were pretreated with siRNA HnRNP U, SIRT1 adenoviral vectors, resveratrol, and siRNA SIRT1, following stimulation with H2O2. We found that the protein levels of SIRT1 and HnRNP U were down-regulation in aged rat liver fibrotic tissues, with an accumulation of NLRP3 inflammasome and activation of the p53/p21 pathway in liver tissue, as well as an increased level of plasma IL-1β secretion. In comparison, these effects were reversed by overexpressing SIRT1 with adenoviral vectors. Acetylation of HnRNP U and its sites at K28 and K787 might be potential targets for SIRT1-mediated liver fibrosis in aged rats. Silencing HnRNP U reduced H2O2-induced up-regulation expression of p53, p21, and NLRP3 inflammasome at protein levels. Additionally, H2O2 induced high acetylation of HnRNP U in senescent hepatocytes, whereas overexpressing SIRT1 with adenoviral vectors and resveratrol deacetylate HnRNP U to inhibit NLRP3 inflammasome and the p53/p21 pathway. Besides, the silence of SIRT1 aggravated H2O2-induced p53-related senescence and NLRP3-related inflammation in senescent hepatocytes. Our findings suggested that deacetylation of HnRNPU mediated by SIRT1 attenuated liver fibrosis in the elderly by inhibiting p53/p21 pathway and NLRP3-related inflammation.

Inhibition of SIRT1 relieves hepatocarcinogenesis via alleviating autophagy and inflammation

Imbalanced Sirtuin 1 (SIRT1) levels may lead to liver diseases through abnormal regulation of autophagy, but the roles of SIRT1-regulated autophagy in hepatocellular carcinoma are still controversial. In this study, we found that SIRT1 mRNA and protein levels were upregulated in hepatocellular carcinoma, and high SIRT1 expression hinted an advanced stage and a poor prognosis. The differentially expressed proteins were significantly elevated in autophagy, cellular response to stress, and immune signaling pathways. In a thioacetamide-induced hepatocellular carcinoma mouse model, we found that SIRT1 expression was highly increased with increased autophagy and excessive macrophage inflammatory response. Next, we established a Hepa 1–6 cells and macrophage co-culture system in vitro to model the alteration of tumor microenvironment, and found that the medium from CCl4-treated or SIRT1-overexpressing Hepa 1–6 cells triggered the polarization of macrophage M1, and the culture medium derived from M1 macrophage promoted Hepa 1–6 cells growth and intracellular oxidative stress. The progression of liver fibrosis in the CCl4-induced liver fibrosis mouse model showed that inhibition of SIRT1 alleviated inflammatory response and ameliorated liver fibrosis. These findings suggest that SIRT1-regulated autophagy and inflammation are oncogenic in hepatocarcinogenesis.

SIRT1 regulates hepatic vldlr levels

BackgroundEndoplasmic reticulum (ER) stress-mediated increases in the hepatic levels of the very low-density lipoprotein (VLDL) receptor (VLDLR) promote hepatic steatosis by increasing the delivery of triglyceride-rich lipoproteins to the liver. Here, we examined whether the NAD(+)-dependent deacetylase sirtuin 1 (SIRT1) regulates hepatic lipid accumulation by modulating VLDLR levels and the subsequent uptake of triglyceride-rich lipoproteins.MethodsRats fed with fructose in drinking water, Sirt1−/− mice, mice treated with the ER stressor tunicamycin with or without a SIRT1 activator, and human Huh-7 hepatoma cells transfected with siRNA or exposed to tunicamycin or different inhibitors were used.ResultsHepatic SIRT1 protein levels were reduced, while those of VLDLR were upregulated in the rat model of metabolic dysfunction-associated steatotic liver disease (MASLD) induced by fructose-drinking water. Moreover, Sirt1−/− mice displayed increased hepatic VLDLR levels that were not associated with ER stress, but were accompanied by an increased expression of hypoxia-inducible factor 1α (HIF-1α)-target genes. The pharmacological inhibition or gene knockdown of SIRT1 upregulated VLDLR protein levels in the human Huh-7 hepatoma cell line, with this increase abolished by the pharmacological inhibition of HIF-1α. Finally, SIRT1 activation prevented the increase in hepatic VLDLR protein levels in mice treated with the ER stressor tunicamycin.ConclusionsOverall, these findings suggest that SIRT1 attenuates fatty liver development by modulating hepatic VLDLR levels.

Nephroprotective effect of Ginsenoside Rg1 in lipopolysaccharide-induced sepsis in mice through the SIRT1/NF-κB signaling.

During sepsis, the kidney is one of the most vulnerable organs. Sepsis-associated acute kidney injury (S-AKI) is hallmarked by renal inflammation, apoptosis, and oxidative injury. Ginsenoside Rg1 (Rg1) is a natural product that possesses abundant pharmacological actions and protects against many sepsis-related diseases. Nevertheless, its role and related mechanism in S-AKI remain to be determined. S-AKI was induced using lipopolysaccharide (LPS, 10 mg/kg) via a single intraperitoneal injection. Rg1 (200 mg/kg) was intraperitoneally administered for 3 consecutive days before LPS treatment. For histopathological examination, murine kidney tissues were stained with hematoxylin and eosin. Tubular injury score was calculated to evaluate kidney injury. Serum creatinine and BUN levels were measured for assessing renal dysfunction. The levels and activities of oxidative stress markers (MDA, 4-HNE, PC, GSH, SOD, and CAT) in renal tissue were measured by corresponding kits. Renal cell apoptosis was detected by TUNEL staining. The protein levels of apoptosis-related markers (Bcl-2, Bax, and Cleaved caspase-3), proinflammatory factors, SIRT1, IκBα, p-NF-κB p65, and NF-κB p65 in kidneys were determined using western blotting. Immunofluorescence staining was employed to assess p-NF-κB p65 expression in renal tissues. LPS-induced injury of kidneys and renal dysfunction in mice were ameliorated by Rg1. Rg1 also impeded LPS-evoked renal cell apoptosis in kidneys. Moreover, Rg1 attenuated LPS-triggered inflammation and oxidative stress in kidneys by inhibiting proinflammatory cytokine release, enhancing antioxidant levels and activities, and reducing lipid peroxidation. However, all these protective effects of Rg1 in LPS-induced AKI mice were reversed by EX527, an inhibitor of sirtuin 1 (SIRT1). Mechanistically, Rg1 upregulated SIRT1 protein expression, increased SIRT1 activity, and inactivated NF-κB signaling in the kidney of LPS-induced AKI mice, which was also reversed by EX527. Rg1 ameliorates LPS-induced kidney injury and suppresses renal inflammation, apoptosis, and oxidative stress in mice via regulating the SIRT1/NF-κB signaling.

Synergistic effect of genistein and adiponectin reduces fat deposition in chicken hepatocytes by activating the ERβ-mediated SIRT1-AMPK signaling pathway

Dietary supplementation with bioactive substances that can regulate lipid metabolism is an effective approach for reducing excessive fat deposition in chickens. Genistein (GEN) has the potential to alleviate fat deposition; however, the underlying mechanism of GEN's fat-reduction action in chickens remains unclear. Therefore, the present study aimed to explore the underlying mechanism of GEN on the reduction of fat deposition from a novel perspective: intercellular transmission of adipokine between adipocytes and hepatocytes. The findings showed that GEN enhanced the secretion of adiponectin (APN) in chicken adipocytes, and the enhancement effect of GEN was completely blocked when the cells were pretreated with inhibitors targeting estrogen receptor β (ERβ) or proliferator-activated receptor γ (PPARγ) signals, respectively. Furthermore, the results demonstrated that both co-treatment with GEN and APN or treatment with the medium supernatant (Med SUP) derived from chicken adipocytes treated with GEN significantly decreased the content of triglyceride and increased the protein levels of ERβ, Sirtuin 1 (SIRT1) and phosphor-AMP-activated protein kinase (p-AMPK) in chicken hepatocytes compared to the cells treated with GEN or APN alone. Moreover, the increase in the protein levels of SIRT1 and p-AMPK induced by GEN and APN co-treatment or Med SUP treatment were blocked in chicken hepatocytes pretreated with the inhibitor of ERβ signals. Importantly, the up-regulatory effect of GEN and APN co-treatment or Med SUP treatment on the protein level of p-AMPK was also blocked in chicken hepatocytes pretreated with a SIRT1 inhibitor; however, the increase in the protein level of SIRT1 induced by GEN and APN co-treatment or Med SUP treatment was not reversed when the hepatocytes were pretreated with an AMPK inhibitor. In conclusion, the present study demonstrated that GEN enhanced APN secretion by activating the ERβ-Erk-PPARγ signaling pathway in chicken adipocytes. Subsequently, adipocyte-derived APN synergized with GEN to activate the ERβ-mediated SIRT1-AMPK signaling pathway in chicken hepatocytes, ultimately reducing fat deposition. These findings provide substantial evidence from a novel perspective, supporting the potential use of GEN as a dietary supplement to prevent excessive fat deposition in poultry.

Gracilaria chorda attenuates obesity-related muscle wasting through activation of SIRT1/PGC1α in skeletal muscle of mice.

Gracilaria chorda (GC) is a red algal species that is primarily consumed in Asia. Here, we investigated the effect of GC on obesity-related skeletal muscle wasting. Furthermore, elucidating its impact on the activation of sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) constituted a critical aspect in understanding the underlying mechanism of action. In this study, 6-week-old male C57BL/6 mice were fed a high-fat diet (HFD) for 8 weeks to induce obesity, then continued on the HFD for another 8 weeks while orally administered GC. GC decreased ectopic fat accumulation in skeletal muscle and increased muscle weight, size, and function in obese mice. Furthermore, GC reduced skeletal muscle atrophy and increased hypertrophy in mice. We hypothesized that the activation of SIRT1/PGC1α by GC regulates skeletal muscle atrophy and hypertrophy. We observed that GC increased the expression of SIRT1 and PGC1α in skeletal muscle of mice and in C2C12 cells, which increased mitochondrial function and biogenesis. In addition, when C2C12 cells were treated with the SIRT1-specific inhibitor EX-527, no changes were observed in the protein levels of SIRT1 and PGC1α in the GC-treated C2C12 cells. Therefore, GC attenuated obesity-related muscle wasting by improving mitochondrial function and biogenesis through the activation of SIRT1/PGC1α in the skeletal muscle of mice.

Coptisine prevents angiotensin II‑induced endothelial cell injury and senescence via the lncRNA SNHG12/miR‑603/NAMPT pathway.

Atherosclerosis (AS) is a major health problem and targeting the associated molecular pathways is critical for developing therapies. The present study investigated the effect of coptisine on human umbilical vein endothelial cells (HUVECs) in response to angiotensin II (Ang II) induction by focusing on cellular senescence, apoptosis and inflammation. HUVECs were treated with different Ang II concentrations and long non-coding RNA small nucleolar RNA host gene 12 (SNHG12), microRNA (miRNA/miR)-603 and nicotinamide phosphoribosyltransferase (NAMPT) expressions were assessed. Cell viability, nicotinamide adenine dinucleotide (NAD+) levels, senescence, apoptosis and inflammation were assessed. The interactions among SNHG12, miR-603 and NAMPT were investigated using dual-luciferase reporter gene assays and RNA pull-down experiments. Coptisine treatment increased SNHG12 expression and attenuated Ang II-induced adverse effects in HUVECs. SNHG12 silencing abrogated coptisine's protective effects, indicating that SNHG12 is a key mediator. SNHG12 targets miR-603, which then directly targets NAMPT, an age-related gene involved in NAD(+) regulation. Coptisine modulated the SNHG12/miR-603/NAMPT pathway and miR-603 inhibition enhanced the protective effects of coptisine. NAMPT overexpression reversed the negative effects of miR-603 and enhanced the protective effect of the miR-603 inhibitor. Finally, the protective mechanism of coptisine is linked to the regulation of NAD(+), sirtuin 3 (SIRT3) and p53. Coptisine treatment counteracted the AngII-induced increase in SIRT3 and p53 protein levels, whereas the miR-603 inhibitor potentiated the effect of coptisine. SNHG12 knockdown partially abolished these effects, which were reversed by NAMPT overexpression. In conclusion, the present study revealed a novel protective mechanism involving the SNHG12/miR-603/NAMPT pathway in HUVECs exposed to Ang II, highlighting the potential therapeutic application of coptisine in treating atherosclerosis. These results suggested that coptisine exerts its protective effects by modulating the SNHG12/miR-603/NAMPT axis, which ultimately affects the regulation of NAD(+), SIRT3 and p53. Future studies should explore the potential of the SNHG12/miR-603/NAMPT pathway as a target for developing novel AS therapies.

Effects of sirtuin 1 deficiency on trophoblasts and its implications in the pathogenesis of pre-eclampsia

Background Sirtuin 1 (SIRT1) is mainly localised in syncytiotrophoblasts and cytotrophoblasts, and is involved in pregnancy regulation. However, data on the association between SIRT1 and pre-eclampsia (PE) remains limited. This study aimed to investigate the role of SIRT1 in PE pathophysiology. Methods Placental SIRT1 expression, as well as serum SIRT1, placental growth factor (PlGF), and soluble FMS-like tyrosine kinase 1 (sFlt-1) levels, were measured using quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assays in 40 healthy pregnant women (NP group) and 40 women with severe PE (PE group). Additionally, the effects of SIRT1 on the migration, invasion, PlGF, and sFlt-1 secretion of HTR-8/SVneo cells were analysed. Results SIRT1 expression was significantly reduced in the placenta of patients with severe PE compared with that in healthy pregnant women. Compared with the NP group, serum SIRT1 and PlGF expression was significantly lower in the PE group; however, the expression of serum sFlt-1 was significantly higher in the PE group. Correlation analysis showed that in the PE group, placental SIRT1 protein levels positively correlated with serum PlGF levels (r = 0.468, P = .002) and negatively correlated with serum sFlt-1 levels (r = −0.542, P < .001). Cells with downregulated SIRT1 had a significantly shorter migration distance and a prominently reduced number of invasive cells compared with the corresponding negative control group, suggesting that SIRT1 deficiency may inhibit the migration and invasive ability of HTR-8/SVneo cells. The opposite results were observed after transfection with lentivirus overexpressing SIRT1. Compared with the corresponding controls, cells with downregulated SIRT1 had significantly reduced PlGF levels and significantly increased sFlt-1 levels in the cell culture supernatants, whereas SIRT1 overexpression produced the opposite results. Conclusions SIRT1 deficiency may contribute to the pathogenesis of pre-eclampsia by reducing trophoblastic migration, invasion, and PlGF secretion and increasing sFlt-1 secretion.

Cardioprotective effects of calorie restriction against inflammation and apoptosis in ovariectomized obese rats: Role of classical estrogen receptors and SIRT1

AimObesity is a metabolic complication linked with bad eating habits and a sedentary lifestyle, and the heart is one of the target organs damaged by it. Estrogen deficiency during menopause worsens the situation. Calorie restriction (CR) can contribute to reducing cardiovascular disease (CVD) in postmenopausal conditions. Thus, the effects of CR on inflammation and apoptosis in ovariectomized rats' hearts with obesity were studied. MethodFemale Wistar rats were categorized into Sham and OVX (ovariectomized) groups and received a standard diet (SD) or high-fat diet (60%HFD) or calorie restriction (30% CR) for 16 weeks. The real-time PCR method was used to evaluate the inflammatory markers and estrogen receptors gene expression. Western-blot and ELISA methods were respectively used for the measurement of apoptosis and SIRT1 protein expression. ResultsHFD led to the elevation of body weight, IL-6 (interleukin-6) and TNF-α (tumor necrosis factor-α) and reduction of IL-10 (interleukin-10) gene expressions, and also an increment in protein levels of cleaved caspase-3, Bax and Bax/Bcl2 ratio and decrement in Bcl-2 in OVX rats (P < 0.001). Additionally, HFD reduced SIRT1 (sirtuin1) protein levels, ERα (estrogen receptor α), and ERβ (estrogen receptor β) gene expressions (P < 0.001). In contrast, CR declined body weight, IL-6 and TNF-α (P < 0.001), increased IL-10 expressions (P < 0.05), decreased cleaved caspase-3 (P < 0.001), Bax (P < 0.01), and Bax/Bcl2 ratio (P < 0.05), enhanced Bcl-2 (P < 0.001), increased SIRT1 (P < 0.05) and ERα (P < 0.001) and ERβ (P < 0.01) expressions. ConclusionCR through the SIRT1 regulation and estrogen receptors attenuate obesity-induced-cardiac inflammation and apoptosis. CR can be a cardioprotective candidate in postmenopausal conditions.

Evaluation of the Relationship between Aromatase/Sirtuin1 Interaction and miRNA Expression in Human Neuroblastoma Cells.

Changes in activation/inhibition of Sirtuin-1 (SIRT1) and aromatase play an important role in a plethora of diseases. MicroRNAs (miRNAs) modulate multiple molecular pathways and affect a substantial number of physiological and pathological processes. The aim of this study was to investigate any possible interaction between aromatase and SIRT1 in SH-SY5Y cells and to see how there is a connection between this interaction and miRNA expression, if there is an interaction. In this study, cells were incubated in serum-deprived media for 6, 12, and 24 h. Aromatase and SIRT1 expressions were evaluated by Western blot. The IC50 concentration of SIRT1 activator (SRT1720), SIRT1 inhibitor (EX527), and aromatase inhibitors (letrozole and fadrozole) was determined by the XTT method. Then, CYP19A1 and SIRT1 levels were evaluated in the presence of SIRT1 siRNA or IC50 values for each activator/inhibitor. Finally, CYP19A1, SIRT1 expression and miRNA target gene were assessed with bioinformatic approaches. Aromatase and SIRT1 protein levels were significantly elevated in the cells incubated at 24 h in serum-deprived media (p ≤ 0.05). SIRT1 also positively regulated CYP19A1 in SH-SY5Y cells in media with/without FBS. Serum deprivation depending on time course caused changes in the oxidant/ antioxidant system. While oxidative stress index tended to decrease in the absence of FBS at 24 h compared to the control, it showed a significant decrease at 48 h in a serum-deprived manner (p ≤ 0.001). As a result of bioinformatics analysis, we determined 3 miRNAs that could potentially regulate SIRT1 and CYP19A1. hsa-miR-27a-3p and hsa-miR-181a-5p correlated in terms of their expressions at 24 h compared to 12 h, and there was a significant decrease in the expression of these miRNAs. On the contrary, the expression of hsa-miR-30c-5p significantly increased at 24 h compared to 12 h. Considering the results, a direct link between aromatase and SIRT1 was observed in human neuroblastoma cells. The identification of key miRNAs, hsa-miR-27a-3p, hsa-miR-30c-5p, and hsa-miR-181a-5p targeting both aromatase and SIRT1, provides an approach with novel insights on neurology-associated diseases.

Chito-oligosaccharides and macrophages have synergistic effects on improving ovarian stem cells function by regulating inflammatory factors

BackgroundChronic low-grade inflammation and ovarian germline stem cells (OGSCs) aging are important reasons for the decline of ovarian reserve function, resulting in ovarian aging and infertility. Regulation of chronic inflammation is expected to promote the proliferation and differentiation of OGSCs, which will become a key means for maintaining and remodeling ovarian function. Our previous study demonstrated that Chitosan Oligosaccharides (Cos) promoted the OGSCs proliferation and remodelled the ovarian function through improving the secretion of immune related factors,but the mechanism remains unclear, and the role of macrophages, the important source of various inflammatory mediators in the ovary needs to be further studied. In this study, we used the method of macrophages and OGSCs co-culture to observe the effect and mechanism of Cos on OGSCs, and explore what contribution macrophages give during this process. Our finding provides new drug treatment options and methods for the prevention and treatment of premature ovarian failure and infertility.MethodsWe used the method of macrophages and OGSCs co-culture to observe the effect and mechanism of Cos on OGSCs, and explore the important contribution of macrophages in it. The immunohistochemical staining was used to locate the OGSCs in the mouse ovary. Immunofluorescent staining, RT-qPCR and ALP staining were used to identify the OGSCs. CCK-8 and western blot were used to evaluate the OGSCs proliferation. β-galactosidase(SA-β-Gal) staining and western blot were used to detect the changing of cyclin-dependent kinase inhibitor 1A(P21), P53, Recombinant Sirtuin 1(SIRT1) and Recombinant Sirtuin 3(SIRT3). The levels of immune factors IL-2, IL-10, TNF-α and TGF-β were explored by using Western blot and ELISA.ResultsWe found that Cos promoted OGSCs proliferation in a dose-and time-dependent manner, accompanied by IL-2, TNF-α increase and IL-10, TGF-β decrease. Mouse monocyte-macrophages Leukemia cells(RAW) can also produce the same effect as Cos. When combined with Cos, it can enhance the proliferative effect of Cos in OGSCs, and further increase IL-2, TNF-α and further decrease IL-10, TGF-β. The macrophages can enhance the proliferative effect of Cos in OGSCs is also associated with the further increase in IL-2, TNF-α and the further decrease in IL-10, TGF-β. In this study, we determined that the anti-aging genes SIRT-1 and SIRT-3 protein levels were increased by Cos and RAW respectively, whereas the senescence-associated SA-β-Gal and aging genes P21 and P53 were decreased. Cos and RAW had a protective effect on OGSCs delaying aging. Furthermore, RAW can further decrease the SA-β-Gal and aging genes P21 and P53 by Cos, and further increase SIRT1 and SIRT3 protein levels in OGSCs by Cos.ConclusionIn conclusion, Cos and macrophages have synergistic effects on improving OGSCs function and delaying ovarian aging by regulating inflammatory factors.

Ellagic acid ameliorates aging-induced renal oxidative damage through upregulating SIRT1 and NRF2

BackgroundAging is associated with impaired renal function and structural alterations. Oxidative stress plays a vital role in renal senescence and damage. Sirtuin 1 (SIRT1) is thought to protect cells from oxidative stress through nuclear factor erythroid 2-related factor 2 (NRF2). Ellagic acid (EA), a natural antioxidant, has been demonstrated to have renoprotective roles in vitro and in vivo. This study investigated if SIRT1 and NRF2 mediate the protective effects of EA in aged kidneys.MethodsMale Wistar rats were divided into three groups including young (4 months), old, and old + EA (25 months). Young and old groups received EA solvent, while the old + EA group was treated with EA (30 mg/kg) by gavage for 30 days. Then, the level of renal oxidative stress, SIRT1 and NRF2 expression, kidney function parameters, and histopathological indices were measured.ResultsTreatment with EA significantly increased the level of antioxidant enzymes and reduced malondialdehyde concentration (P < 0.01). Moreover, EA administration remarkably upregulated mRNA and protein levels of SIRT1 and NRF2 as well as deacetylated NRF2 protein (P < 0.05). Additionally, EA treated rats improved kidney function and histopathological scores (P < 0.05).ConclusionsThese findings suggest that ellagic acid exerts protective effects on aged kidneys by activating SIRT1 and NRF2 signaling.

The effect of 8 weeks of vitamin D supplementation and aerobic exercise on sirtuin-1 protein levels and oxidative stress markers of myocardial tissue in middle-aged male rats

زمینه و هدف: فعالیت ورزشی و مکمل‌یاری ویتامین D نقش مهمی در سلامت قلبی- عروقی دارند. با این حال، آثار ترکیب این دو راهبرد و نقش مولکولی آن‌ها در سازگاری‌های قلبی کمتر شناخته شده است. ازاین‌رو تحقیق حاضر با هدف تعیین تأثیر مکمل‌یاری ویتامین D و تمرین هوازی بر نشانگرهای فشار اکسایشی و پروتئین سیرتوئین 1 (SIRT-1) در بافت میوکارد موش‌های صحرایی نر میانسال انجام گرفت.مواد و روش‌ها: 32 سر موش صحرایی نر با دامنة سنی 12–14 ماه و با دامنة وزنی 350–400 گرم پس از طی دو هفته آشناسازی و انجام آزمون حداکثر سرعت هوازی و اندازه‌گیری وزن آن‌ها، به‌طور تصادفی به چهار گروه کنترل (Con)، تمرین هوازی (AT)، ویتامین D (Vit-D) و تمرین هوازی + ویتامین D (AT+Vit_D) تقسیم شدند. برنامة اصلی تمرین شامل هشت هفته تمرین فزاینده و پنج جلسه در هفته بود. گروه Vit_D و AT+Vit-D 500 واحد ویتامین D همراه با 3/0 میلی‌لیتر روغن زیتون به ازای هر کیلوگرم از وزن بدن به‌صورت یک روز در میان دریافت کردند. همچنین از روغن زیتون به‌عنوان دارونما استفاده شد. 48 ساعت پس از آخرین جلسة مداخله بافت قلب حیوانات خارج شد. میزان فعالیت سوپراکسید دسموتاز (SOD)، گلوتاتیون پراکسیداز (GPx) و نیز غلظت مالون دی‌آلدهید (MDA)، هیدروژن پراکسید (H2O2) و پروتئین SIRT-1 اندازه‌گیری شد. تجزیه‌وتحلیل داده‌ها از طریق آزمون آنوا یکراهه در سطح 05/0 P< انجام گرفت.نتایج: یافته‌ها نشان داد مقادیر SIRT-1 به‌طور معناداری در گروه AT بیشتر از گروه Con بود (05/0P<). همچنین مقادیر MDA در گروه AT نسبت به گروه Con کمتر بود (05/0P<). بین دیگر گروه‌های مورد بررسی تفاوت معناداری در مقادیر MDA و SIRT-1 مشاهده نشد (05/0P>). افزون‌بر این تفاوت معناداری در مقادیر GPx، SOD و H2O2 بین گروه‌های مورد بررسی مشاهده نشد (05/0P>).نتیجه‌گیری: در کل، یافته‌های تحقیق حاضر نشان داد تمرین منظم هوازی برای کاهش آسیب‌های اکسایشی بافت قلب در دورة میانسالی ممکن است سودمند باشد. همچنین تمرین هوازی در میانسالی به افزایش پروتئین SIRT-1 منجر می‌شود. با توجه به نقش مهم SIRT-1 در پیشگیری از بیماری‌های قلبی و تقویت دستگاه دفاع ضداکسایشی، به‌نظر می‌رسد تمرین هوازی راهبردی مؤثر برای کاهش بیماری‌های قلبی- عروقی مرتبط با افزایش سن باشد. همچنین یافته‌های پژوهش حاضر نشان داد مکمل‌یاری ویتامین D در کنار تمرین هوازی آثار هم‌افزایی در بهبود نشانگرهای فشار اکسایشی یا SIRT-1 ایجاد نمی‌کند. با این حال با توجه به حجم کم مطالعات در این مورد و نیز برخی محدودیت‌های پژوهش حاضر پیشنهاد می‌شود تحقیقات بیشتری در این باره انجام گیرد.

Molecular Mechanisms Underlying the Anti-Inflammatory Properties of (R)-(-)-Carvone: Potential Roles of JNK1, Nrf2 and NF-κB.

To explore the molecular mechanisms underlying the anti-inflammatory activity of (R)-(-)-carvone, we evaluated its ability to inhibit the signaling pathways involving the mitogen-activated protein kinases (MAPKs) and the transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). (R)-(-)-carvone significantly decreased c-Jun N-terminal kinase (JNK) 1phosphorylation, but not that of the other MAPKs, induced by bacterial lipopolysaccharides (LPS) in the RAW 264.7 macrophage cell line. Although (R)-(-)-carvone significantly inhibited resynthesis of the inhibitor of NF-κB (IκB)-α induced by LPS, it did not interfere with the canonical NF-κB activation pathway, suggesting that it may interfere with its transcriptional activity. (R)-(-)-carvone also showed a tendency to decrease the levels of acetylated NF-κB/p65 in the nucleus, without affecting the activity and protein levels of Sirtuin-1, the major NF-κB/p65 deacetylating enzyme. Interestingly, the nuclear protein levels of the transcription factor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and the expression of its target,, heme oxygenase-1 (HO-1), an antioxidant enzyme, also showed a tendency to increase in the presence of (R)-(-)-carvone. Taken together, these results suggest that the ability of (R)-(-)-carvone to inhibit JNK1 and to activate Nrf2 can underlie its capacity to inhibit the transcriptional activity of NF-κB and the expression of its target genes. This study highlights the diversity of molecular mechanisms that can be involved in the anti-inflammatory activity of monoterpenes.

Low-Intensity Exercise Affects Cardiac Fatty Acid Oxidation by Increasing the Nuclear Content of PPARα, FOXO1, and Lipin1 in Fructose-Fed Rats.

Background and Aim: Excessive fructose consumption along with a sedentary lifestyle provokes metabolic disorders and cardiovascular diseases. Fructose overload causes cardiac insulin resistance and increases reliance on fatty acid (FA) uptake and catabolism. The cardiometabolic benefits of exercise training have long been appreciated. The goal of the presented study is to shed a new light to the preventive role of exercise training on cardiac lipid metabolism in fructose-fed rats. Methods: Male Wistar rats were divided into control (C), sedentary fructose (F), and exercised fructose (EF) groups. Fructose was given as a 10% fructose solution in drinking water for 9 weeks. Low-intensity exercise training was applied for 9 weeks. The protein expression and subcellular localization of Lipin1, peroxisome proliferator-activated receptor α (PPARα), and peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC1) were analyzed in the heart using Western blot. Cardiac forkhead box transcription factor 1 (FOXO1) and sirtuin 1 (SIRT1) protein levels were also evaluated. Gene expression of long-chain acyl-CoA dehydrogenase was analyzed by quantitative polymerase chain reaction. Results: Exercise training has augmented the expression of main regulators of FA oxidation in the heart and achieves its effect by increasing the nuclear content of PPARα, Lipin1, and FOXO1 compared with the fructose group (P = 0.0422, P = 0.000045, P = 0.00958, respectively). In addition, Lipin1, FOXO1, and SIRT1 were increased in nuclear extract after exercise compared with the control group (P = 0.000043, P = 0.0417, P = 0.0329, respectively). In cardiac lysate, low-intensity exercise caused significantly increased protein level of PPARα, PGC1, FOXO1, and SIRT1 compared with control (P = 0.0377, P = 0.0275, P = 0.0096, P = 0.0282, respectively) and PGC1 level compared with the fructose group (P = 0.0417). Conclusion: The obtained results imply that the heart with a metabolic burden additionally relies on FA as an energy substrate after low-intensity running.

Genistein activated SIRT1-AMPK signaling pathway mediated by ERβ-FOXO1-Nampt to reduce fat accumulation in chicken hepatocytes

Excessive fat accumulation in broiler chickens would seriously threaten the poultry industry. It leads to lower feed conversion rate and worse meat quality. Even worse, it harms the consumers' health due to the intake of high-fat chicken products. Dietary supplements with bioactive ingredients have been considered an effective way to solve this problem. Genistein is the primary phytoestrogen in soybean. Its fat-reduction effect has been reported, but the molecular mechanism is unclear. The present study found that genistein reduced lipid droplets accumulation by regulating lipid metabolism-related factors expression in chicken hepatocytes. The research showed that genistein significantly increased phosphor (p)-AMP-activated protein kinase (p-AMPK) and Sirtuin 1 (SIRT1) protein expressions. The effect of genistein on reducing lipid droplets accumulation and upregulating p-AMPK protein level was blocked entirely when pretreated with SIRT1 inhibitor. These results implied that SIRT1 is required to activate AMPK. Furthermore, genistein treatment significantly upregulated the SIRT1 protein level when pretreated with AMPK inhibitor. We demonstrated that the activation of estrogen receptor β-Forkhead box O1-Nicotinamide phosphoribosyl transferase (ERβ-FOXO1-Nampt) signaling pathway upregulated the NAD+ concentration in hepatocytes, and activated SIRT1 ultimately. In summary, we demonstrated that genistein suppressed lipid droplets accumulation in chicken hepatocytes by activating SIRT1-AMPK. The SIRT1-AMPK signaling pathway was mediated by ERβ-FOXO1-Nampt. These findings increase our understanding of the mechanisms of genistein on fat reduction, and provide compelling evidence for it as a nutritional supplement to prevent excessive fat deposition and lipid metabolism-related diseases in animals and even humans.

Downregulation of SIRT3 Aggravates Lung Ischemia Reperfusion Injury by Increasing Mitochondrial Fission and Oxidative Stress through HIF-1α-Dependent Mechanisms.

Lung ischemia-reperfusion injury (LIRI) is a severe multifaceted pathological condition that can lead to poor patient outcome where oxidative stress and the resulting inflammatory response can trigger and exacerbate tissue damage in LIRI patients. Sirtuin3 (SIRT3), a member of the sirtuin family, protects against oxidative stress-related diseases. However, it remains unclear if and how SIRT3 alleviates lung injury induced by ischemia/reperfusion (I/R). Our previous study showed that lung tissue structures were severely damaged at 6 h after lung I/R in mice, however, repair of the injured lung tissue was significant at 24 h. In this study, we found that both SIRT3 mRNA and protein levels were markedly increased at 24 h after lung I/R in vivo. Meanwhile, inhibition of SIRT3 aggravated lung injury and inflammation, augmented mitochondrial fission and oxidative stress and increased Hypoxia-inducible factor-1α (HIF-1α) expression in vivo. The results suggest that SIRT3 may be an upstream regulator of HIF-1α expression. Knockdown of SIRT3 resulted in excessive mitochondrial fission and increased oxidative stress in vitro, and we found that knocking down the expression of HIF-1α alleviated these changes. This suggests that the SIRT3-HIF-1α signaling pathway is involved in regulating mitochondrial function and oxidative stress. Furthermore, inhibition of dynamin-related protein 1 (Drp-1) by the inhibitor of mitophagy, Mdivi-1, blocked mitochondrial fission and alleviated oxidative stress in vitro. Taken together, our results demonstrated that downregulation of SIRT3 aggravates LIRI by increasing mitochondrial fission and oxidative stress. Activation of SIRT3 inhibits mitochondrial fission and this mechanism may serve as a new therapeutic strategy to treat LIRI.