To investigate the effect of Huazhi Rougan Granules(HZRG) on autophagy in a steatotic hepatocyte model of free fatty acid(FFA)-induced nonalcoholic fatty liver disease(NAFLD) and explore the possible mechanism. FFA solution prepared by mixing palmitic acid(PA) and oleic acid(OA) at the ratio of 1∶2 was used to induce hepatic steatosis in L02 cells after 24 h treatment, and an in vitro NAFLD cell model was established. After termination of incubation, cell counting kit-8(CCK-8) assay was performed to detect the cell viability; Oil red O staining was employed to detect the intracellular lipid accumulation; enzyme-linked immunosorbnent assay(ELISA) was performed to measure the level of triglyceride(TG); to monitor autophagy in L02 cells, transmission electron microscopy(TEM) was used to observe the autophagosomes; LysoBrite Red was used to detect the pH change in lysosome; transfection with mRFP-GFP-LC3 adenovirus was conducted to observe the autophagic flux; Western blot was performed to determine the expression of autophagy marker LC3B-Ⅰ/LC3B-Ⅱ, autophagy substrate p62 and silent information regulator 1(SIRT1)/adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK) signaling pathway. NAFLD cell model was successfully induced by FFA at 0.2 mmol·L~(-1) PA and 0.4 mmol·L~(-1) OA. HZRG reduced the TG level(P<0.05, P<0.01) and the lipid accumulation of FFA-induced L02 cells, while elevated the number of autophagosomes and autophagolysosomes to generate autophagic flux. It also affected the functions of lysosomes by regulating their pH. Additionally, HZRG up-regulated the expression of LC3B-Ⅱ/LC3B-Ⅰ, SIRT1, p-AMPK and phospho-protein kinase A(p-PKA)(P<0.05, P<0.01), while down-regulated the expression of p62(P<0.01). Furthermore, 3-methyladenine(3-MA) or chloroquine(CQ) treatment obviously inhibited the above effects of HZRG. HZRG prevented FFA-induced steatosis in L02 cells, and its mechanism might be related to promoting autophagy and regulating SIRT1/AMPK signaling pathway.
Humans ; Non-alcoholic Fatty Liver Disease/metabolism* ; Sirtuin 1/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Fatty Acids, Nonesterified/metabolism* ; Autophagy ; Liver

This study aims to investigate the role of slient mating-type information regulation 2 homolog 1(SIRT1)/tuberous sclerosis complex 2(TSC2)/mammalian target of rapamycin(mTOR) signaling pathways in the Periplaneta americana extract CⅡ-3-induced senescence of human leukemia K562 cells. K562 cells were cultured in vitro and treated with 0(control), 5, 10, 20, 40, 80, and 160 μg·mL~(-1) of P. americana extract CⅡ-3. Cell counting kit-8(CCK-8) and flow cytometry were employed to examine the proliferation and cell cycle of the K562 cells. Senescence-associated β-galactosidase stain kit(SA-β-gal) was used to detect the positive rate of senescent cells. Mitochondrial membrane potential was detected by flow cytometry. The relative mRNA level of telomerase reverse transcriptase(TERT) was determined by fluorescence quantitative PCR. The mRNA and protein levels of SIRT1, TSC2, and mTOR were determined by fluorescence quantitative PCR and Western blot, respectively. The results showed that CⅡ-3 significantly inhibited the proliferation of K562 cells and the treatment with 80 μg·mL~(-1) CⅡ-3 for 72 h had the highest inhibition rate. Therefore, 80 μg·mL~(-1) CⅡ-3 treatment for 72 h was selected as the standard for subsequent experiments. Compared with the control group, CⅡ-3 increased the proportion of cells arrested in G_0/G_1 phase, decreased the proportion of cells in S phase, increased the positive rate of SA-β-Gal staining, elevated the mitochondrial membrane potential and down-regulated the mRNA expression of TERT. Furthermore, the mRNA expression of SIRT1 and TSC2 was down-regulated, while the mRNA expression of mTOR was up-regulated. The protein expression of SIRT1 and p-TSC2 was down-regulated, while the protein expression of p-mTOR was up-regulated. The results indicated that P. americana extract CⅡ-3 induced the senescence of K562 cells via the SIRT1/mTOR signaling pathway.
Humans ; Animals ; Periplaneta ; Sirtuin 1/genetics* ; K562 Cells ; Signal Transduction ; TOR Serine-Threonine Kinases/genetics* ; RNA, Messenger ; Mammals

OBJECTIVE: To investigate the role of the SIRT1/NF-κB pathway in mediating the effect of puerarin against lipopolysaccharide (LPS)-induced acute kidney injury (AKI). METHODS: Fifteen BALB/C mice were randomized into control group, LPS group and puerarin treatment group, and in the latter two groups, the mice were given an intraperitoneal injection of LPS (5 mg/kg), followed by daily injection of normal saline for 3 days or injection of puerarin (25 mg/kg) given 1 h later and then on a daily basis for 3 days. On day 5 after modeling, the kidney tissues were taken for histological observation and detection of cell apoptosis. The renal function indexes including urea nitrogen (BUN), serum creatinine (Scr) and kidney injury molecule 1 (KIM-1) and the levels of tumor necrosis factor (TNF-α) and interleukin 1β (IL-1β) were measured, and the expressions of SIRT1 and NF-κB-p65(acetyl K310) in the renal tissues were detected. RESULTS: Intraperitoneal injection of LPS caused obvious glomerular capillary dilatation, hyperemia, renal interstitial edema, and renal tubular epithelial cell swelling and deformation in the mice. The mouse models of LPS-induced AKI also showed significantly increased renal tubular injury score and renal cell apoptosis (P < 0.01) with increased serum levels of BUN, Scr, KIM-1, TNF-α and IL-1β (P < 0.01), enhanced renal expressions of TNF-α, IL-1β and NF-κB p65(acetyl K310) (P < 0.01) and lowered renal expression of SIRT1 (P < 0.05). Treatment with puerarin effectively alleviated LPS-induced renal interstitial edema and renal tubular epithelial cell shedding, lowered renal tubular injury score (P < 0.01) and renal cell apoptosis rate (P < 0.01), and decreased serum levels of BUN, Scr, KIM, TNF-α and IL-1β (P < 0.01). Puerarin treatment significantly reduced TNF-α, IL-1β and NF-κB p65 (acetyl K310) expression in the renal tissue (P < 0.05) and increased SIRT1 expression by 17% (P < 0.05) in the mouse models. CONCLUSION Puerarin can effectively alleviate LPS-induced AKI in mice possibly by modulating the SIRT1/NF-κB signaling pathway.
Animals ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; Lipopolysaccharides ; Sirtuin 1 ; Tumor Necrosis Factor-alpha ; Acute Kidney Injury ; Disease Models, Animal ; Edema

Resveratrol (RES), a natural polyphenolic phytochemical, has been suggested as a putative anti-aging molecule for the prevention and treatment of Alzheimer's disease (AD) by the activation of sirtuin 1 (Sirt1/Sir2). In this study, we tested the effects of RES and Sirt1/Sir2 on sleep and courtship memory in a Drosophila model by overexpression of amyloid precursor protein (APP), whose duplications and mutations cause familial AD. We found a mild but significant transcriptional increase of Drosophila Sir2 (dSir2) by RES supplementation for up to 17 days in APP flies, but not for 7 days. RES and dSir2 almost completely reversed the sleep and memory deficits in APP flies. We further demonstrated that dSir2 acts as a sleep promotor in Drosophila neurons. Interestingly, RES increased sleep in the absence of dSir2 in dSir2-null mutants, and RES further enhanced sleep when dSir2 was either overexpressed or knocked down in APP flies. Finally, we showed that Aβ aggregates in APP flies were reduced by RES and dSir2, probably via inhibiting Drosophila β-secretase (dBACE). Our data suggest that RES rescues the APP-induced behavioral deficits and Aβ burden largely, but not exclusively, via dSir2.
Animals ; Alzheimer Disease/metabolism* ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/metabolism* ; Drosophila/physiology* ; Drosophila Proteins/metabolism* ; Resveratrol/pharmacology* ; Sirtuin 1 ; Sleep

Sirtuin 1

OBJECTIVE: To investigate the role and mechanism of silent information regulator 1 (SIRT1) in regulating nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in oxidative stress and inflammatory response to sepsis-induced liver injury. METHODS: A total of 24 male Sprague-Dawley (SD) rats were randomly divided into sham operation (Sham) group, cecal ligation and puncture (CLP) group, SIRT1 agonist SRT1720 pretreatment (CLP+SRT1720) group and SIRT1 inhibitor EX527 pretreatment (CLP+EX527) group, with 6 rats in each group. Two hours before operation, SRT1720 (10 mg/kg) or EX527 (10 mg/kg) were intraperitoneally injected into the CLP+SRT1720 group and CLP+EX527 group, respectively. Blood was collected from the abdominal aorta at 24 hours after modeling and the rats were sacrificed for liver tissue. The serum levels of interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by microplate method. Hematoxylin-eosin (HE) staining was used to observe the pathological injury of rats in each group. The levels of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), glutathione (GSH) and superoxide dismutase (SOD) in liver tissue were detected by corresponding kits. The mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting. RESULTS: Compared with the Sham group, the serum levels of IL-6, IL-1β, TNF-α, ALT and AST in the CLP group were significantly increased; histopathological results showed that liver cords were disordered, hepatocytes were swollen and necrotic, and a large number of inflammatory cells infiltrated; the contents of MDA and 8-OHdG in liver tissue increased, while the contents of GSH and SOD decreased; and the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were significantly decreased. These results suggest that sepsis rats have liver dysfunction, and the levels of SIRT1, Nrf2, HO-1 and antioxidant protein in liver tissues were decreased, while the levels of oxidative stress and inflammation were increased. Compared with the CLP group, the levels of inflammatory factors and oxidative stress were significantly decreased in the CLP+SRT1720 group, the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were significantly increased [IL-6 (ng/L): 34.59±4.21 vs. 61.84±3.78, IL-1β (ng/L): 41.37±2.70 vs. 72.06±3.14, TNF-α (ng/L): 76.43±5.23 vs. 130.85±5.30, ALT (U/L): 30.71±3.63 vs. 64.23±4.59, AST (U/L): 94.57±6.08 vs. 145.15±6.86, MDA (μmol/g): 6.11±0.28 vs. 9.23±0.29, 8-OHdG (ng/L): 117.43±10.38 vs. 242.37±11.71, GSH (μmol/g): 11.93±0.88 vs. 7.66±0.47, SOD (kU/g): 121.58±5.05 vs. 83.57±4.84, SIRT1 mRNA (2^-ΔΔCt): 1.20±0.13 vs. 0.46±0.02, Nrf2 mRNA (2^-ΔΔCt): 1.21±0.12 vs. 0.58±0.03, HO-1 mRNA (2^-ΔΔCt): 1.71±0.06 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.89±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.87±0.08 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.93±0.14 vs. 0.54±0.12, all P < 0.05], these results indicated that SIRT1 agonist SRT1720 pretreatment could improve liver injury in sepsis rats. However, pretreatment with SIRT1 inhibitor EX527 showed the opposite effect [IL-6 (ng/L): 81.05±6.47 vs. 61.84±3.78, IL-1β (ng/L): 93.89±5.83 vs. 72.06±3.14, TNF-α (ng/L): 177.67±5.12 vs. 130.85±5.30, ALT (U/L): 89.33±9.52 vs. 64.23±4.59, AST (U/L): 179.59±6.44 vs. 145.15±6.86, MDA (μmol/g): 11.39±0.51 vs. 9.23±0.29, 8-OHdG (ng/L): 328.83±11.26 vs. 242.37±11.71, GSH (μmol/g): 5.07±0.34 vs. 7.66±0.47, SOD (kU/g): 59.37±4.28 vs. 83.57±4.84, SIRT1 mRNA (2^-ΔΔCt): 0.34±0.03 vs. 0.46±0.02, Nrf2 mRNA (2^-ΔΔCt): 0.46±0.04 vs. 0.58±0.03, HO-1 mRNA (2^-ΔΔCt): 0.21±0.03 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.47±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.32±0.07 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.19±0.09 vs. 0.54±0.12, all P < 0.05]. CONCLUSIONS SIRT1 can inhibit the release of proinflammatory factors and alleviate the oxidative damage of hepatocytes by activating Nrf2/HO-1 signaling pathway, thus playing a protective role against CLP-induced liver injury.
Animals ; Male ; Rats ; Actins/metabolism* ; Chemical and Drug Induced Liver Injury, Chronic ; Heme Oxygenase-1/metabolism* ; Interleukin-6 ; NF-E2-Related Factor 2/metabolism* ; Rats, Sprague-Dawley ; RNA, Messenger ; Sepsis/metabolism* ; Signal Transduction ; Sirtuin 1/metabolism* ; Superoxide Dismutase/metabolism* ; Tumor Necrosis Factor-alpha/metabolism*

Silent information regulator 1 (SIRT1) is one of the seven mammalian proteins of the sirtuin family of NAD⁺-dependent deacetylases. SIRT1 plays a pivotal role in neuroprotection and ongoing research has uncovered a mechanism by which SIRT1 may exert a neuroprotective effect on Alzheimer's disease (AD). Growing evidence demonstrates that SIRT1 regulates many pathological processes including amyloid-β precursor protein (APP) processing, neuroinflammation, neurodegeneration, and mitochondrial dysfunction. SIRT1 has recently received enormous attention, and pharmacological or transgenic approaches to activate the sirtuin pathway have shown promising results in the experimental models of AD. In the present review, we delineate the role of SIRT1 in AD from a disease-centered perspective and provides an up-to-date overview of the SIRT1 modulators and their potential as effective therapeutics in AD.
Animals ; Alzheimer Disease ; Amyloid beta-Protein Precursor ; Animals, Genetically Modified ; Sirtuin 1 ; Sirtuins ; Humans

This study aims to explore the anti-depression mechanism of Zuojin Pills based on the plasma constituents, network pharmacology, and experimental verification. UHPLC-TOF-MS was used for qualitative analysis of Zuojin Pills-containing serum. Targets of the plasma constituents and the disease were retrieved from PharmMapper and GeneCards. Then the protein-protein interaction(PPI) network was constructed and core targets were screened for GO term enrichment and KEGG pathway enrichment. Cytoscape 3.7.2 was employed construct the "compound-target-pathway" network and the targets and signaling pathways of Zuojin Pills against depression were predicted. CUMS-induced depression mouse model was established to verify the key targets. The results showed that a total of 21 constituents migrating to blood of Zuojin Pills were identified, which were mainly alkaloids. A total of 155 common targets of the constituents and the disease and 67 core targets were screened out. KEGG enrichment and PPI network analysis showed that Zuojin Pills may play a role in the treatment of depression through AMPK/SIRT1, NLRP3, insulin and other targets and pathways. Furthermore, the results of animal experiments showed that Zuojin Pills could significantly improve the depression behaviors of depression, reduce the levels of IL-1β, IL-6 and TNF-α in hippocampus and serum, activate AMPK/SIRT1 signaling, and reduce the protein expression of NLRP3. In conclusion, Zuojin Pills may play a role in the treatment of depression by activating AMPK/SIRT1 signaling pathway, and inhibiting NLRP3 activation and neuroinflammation in the hippocampus of mice.
Animals ; Mice ; Network Pharmacology ; AMP-Activated Protein Kinases ; Chromatography, High Pressure Liquid ; NLR Family, Pyrin Domain-Containing 3 Protein ; Sirtuin 1 ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

This study aimed to explore the possible effect of Xixin Decoction(XXD) on the learning and memory ability of Alzheimer's disease(AD) model senescence-accelerated mouse-prone 8(SAMP8) and the related mechanism in enhancing neuroprotective effect and reducing neuroinflammation. Forty SAMP8 were randomly divided into a model group(10 mL·kg~(-1)·d~(-1)), a probiotics group(0.39 g·kg~(-1)·d~(-1)), a high-dose group of XXD granules(H-XXD, 5.07 g·kg~(-1)·d~(-1)), a medium-dose group of XXD granules(M-XXD, 2.535 g·kg~(-1)·d~(-1)), and a low-dose group of XXD granules(L-XXD, 1.267 5 g·kg~(-1)·d~(-1)). Eight senescence-accelerated mouse-resistant 1(SAMR1) of the same age and strain were assigned to the control group(10 mL·kg~(-1)·d~(-1)). After ten weeks of intragastric administration, the Morris water maze was used to test the changes in spatial learning and memory ability of mice after treatment. Meanwhile, immunofluorescence staining was used to detect the positive expression of receptor for advanced glycation end products(AGER), Toll-like receptor 1(TLR1), and Toll-like receptor 2(TLR2) in the hippocampal CA1 region of mice. Western blot was employed to test the protein expression levels of silencing information regulator 2 related enzyme 1(SIRT1), AGER, TLR1, and TLR2 in the hippocampus of mice. Enzyme linked immunosorbent assay(ELISA) was applied to assess the levels of Aβ_(1-42) in the hippocampus of mice and the levels of nuclear factor κB p65(NF-κB p65), NOD-like receptor protein 3(NLRP3), tumor necrosis factor-α(TNF-α), and interleukin-1β(IL-1β) in the serum and hippocampus of mice. Compared with the model group, XXD significantly improved the spatial learning and memory ability of SAMP8, increased the expression of neuroprotective factors in the hippocampus, decreased the levels of neuroinflammatory factors, and inhibited the expression of Aβ_(1-42). In particular, H-XXD significantly increased the expression of SIRT1 in the hippocampus of mice, reduced the expression levels of NF-κB p65, NLRP3, TNF-α, and IL-1β in the serum and hippocampus of mice, and decreased the expression of AGER, TLR1, and TLR2 in the hippocampus of mice(P<0.05 or P<0.01). XXD may improve the spatial learning and memory ability of AD model SAMP8 by enhancing the neuroprotective effect and inhibiting neuroinflammation.
Humans ; Neuroprotective Agents/therapeutic use* ; Sirtuin 1/metabolism* ; Toll-Like Receptor 2/metabolism* ; NF-kappa B/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Neuroinflammatory Diseases ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Toll-Like Receptor 1/metabolism* ; Alzheimer Disease/genetics* ; Hippocampus