Apoptotic Effect of Isoimpertorin via Inhibition of c-Myc and SIRT1 Signaling Axis.

Though Isoimperatorin from Angelicae dahuricae is known to have antiviral, antidiabetic, anti-inflammatory and antitumor effects, its underlying antitumor mechanism remains elusive so far. Hence, the apoptotic mechanism of Isoimperatorin was explored in hepatocellular carcinomas (HCCs). In this study, Isoimperatorin inhibited the viability of Huh7 and Hep3B HCCs and increased the subG1 apoptotic portion and also abrogated the expression of pro-poly-ADP ribose polymerase (pro-PARP) and pro-caspase 3 in Huh7 and Hep3B cells. Also, Isoimperatorin abrogated the expression of cyclin D1, cyclin E1, CDK2, CDK4, CDK6 and increased p21 as G1 phase arrest-related proteins in Huh7 and Hep3B cells. Interestingly, Isoimperatorin reduced the expression and binding of c-Myc and Sirtuin 1 (SIRT1) by Immunoprecipitation (IP), with a binding score of 0.884 in Huh7 cells. Furthermore, Isoimperatorin suppressed the overexpression of c-Myc by the proteasome inhibitor MG132 and also disturbed cycloheximide-treated c-Myc stability in Huh7 cells. Overall, these findings support the novel evidence that the pivotal role of c-Myc and SIRT1 is critically involved in Isoimperatorin-induced apoptosis in HCCs as potent molecular targets in liver cancer therapy.

Quercetin and tanshinone prevent mitochondria from oxidation and autophagy to inhibit KGN cell apoptosis through the SIRT1/SIRT3-FOXO3a axis.

Granulosa cells are somatic cells located inside follicles that play a crucial role in the growth and development of follicles. Quercetin and tanshinone are two key monomers in traditional Chinese medicine that have antioxidant and anti-aging properties. The KGN cell apoptosis model caused by triptolide (TP) was employed in this work to investigate granulosa cell death and medication rescue. Quercetin and tanshinone therapy suppressed KGN cell death and oxidation while also regulating the expression of critical apoptosis and oxidation-related markers such as B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax). Further research revealed that the effects of Quercetin and Tanshinone were accomplished via deacetylation of FOXO3A in the cytoplasm and mitochondria via the SIRT1/SIRT3-FOXO3a axis. In summary, Quercetin and tanshinone protect KGN cells from apoptosis by reducing mitochondrial apoptosis and oxidation via the SIRT1/SIRT3-FOXO3a axis.

Diverse Response to Local Pharmacological Blockade of Sirt1 Cleavage in Age-Induced versus Trauma-Induced Osteoarthritis Female Mice.

Objective: Previous studies have shown that the cleavage of Sirt1 contributes to the development of osteoarthritis (OA). In fact, OA was effectively abrogated by the intra-articular (IA) administration of two compounds, one blocking Sirt1 cleavage (CA074me) and the other activating Sirt1 (SRT1720), using a post-traumatically induced model (PTOA) in young female mice. In this study, we attempted to understand if this local treatment is effective in preventing age-associated OA (AOA) progression and symptoms. Design: A group of 17-month-old female C57BL/6J mice were IA administered with CA074me and/or SRT1720 or their combination. Joint histopathological analysis and bone histomorphometry were carried out, with an assessment of knee mechanical hyperalgesia. A serum analysis for NT/CT Sirt1 was carried out along with immunohistochemistry for articular cartilage to detect p16INK4A or γH2A.X. Similarly, meniscal cartilage was monitored for Lef1 and Col1a1 deposition. The data were compared for young female mice subjected to post-traumatic OA (PTOA). Results: Similar to PTOA, combination-treated AOA exhibited improved knee hyperalgesia, yet structural improvements were undetected, corresponding to unchanged NT/CT Sirt1 serum levels. Both AOA and PTOA exhibited unchanged staining for nuclear p16INK4A or γH2A.X and lacked a correlation with OA severity. Contrarily to PTOA, the combination treatment with AOA did not exhibit a local reduction in the Lef1 and Col1 targets. Conclusions: When targeting Sirt1 cleavage, the PTOA and AOA models exhibited a similar pain response to the combination treatment; however, they displayed diverse structural outcomes for joint-related damage, related to Lef1-dependent signaling. Interestingly, nuclear p16INK4A was unaffected in both models, regardless of the treatment's effectiveness. Finally, these findings highlight the variations in the responses between two highly researched OA preclinical models, reflecting OA pathophysiology heterogeneity and variations in gender-related drug-response mechanisms.

The ROS/SIRT1/STAR axis as a target for melatonin ameliorating atrazine-induced mitochondrial dysfunction and steroid disorders in granulosa cells.

The granulosa cells (GCs) of birds are essential for the reproduction and maintenance of populations in nature. Atrazine (ATR) is a potent endocrine disruptor that can interfere with reproductive function in females and Diaminochlorotriazine (DACT) is the primary metabolite of ATR in the organism. Melatonin (MT) is an endogenous hormone with antioxidant properties that plays a crucial role in development of animal germ cells. However, how ATR causes mitochondrial dysfunction, abnormal secretion of steroid hormones, and whether MT prevents ATR-induced female reproductive toxicity remains unclear. Thus, the purpose of this study is to investigate the protective effect of MT against ATR-induced female reproduction. In the present study, the GCs of quail were divided into 6 groups, as follows: C (Serum-free medium), MT (10 µM MT), A250 (250 µM ATR), MA250 (10 µM MT+250 µM ATR), D200 (200 µM DACT) and MD200 (10 µM MT+200 µM DACT), and were cultured for 24 h. The results revealed that ATR prevented GCs proliferation and decreased cell differentiation. ATR caused oxidative damage and mitochondrial dysfunction, leading to disruption of steroid synthesis, which posed a severe risk to GC's function. However, MT supplements reversed these changes. Mechanistically, our study exhibited that the ROS/SIRT1/STAR axis as a target for MT to ameliorate ATR-induced mitochondrial dysfunction and steroid disorders in GCs, which provides new insights into the role of MT in ATR-induced reproductive capacity and species conservation in birds.

Resveratrol induces apoptosis by modulating the reciprocal crosstalk between p53 and Sirt-1 in the CRC tumor microenvironment.

Introduction: P53 represents a key player in apoptosis-induction in cancers including colorectal cancer (CRC) that ranks third worldwide in cancer prevalence as well as mortality statistics. Although a pro-apoptotic effect of resveratrol has been repeatedly proven in CRC cells, its pathway mechanisms are not completely understood, as there are controversial statements in the literature regarding its activation or inhibition of the counteracting proteins Sirt-1 and p53. Methods: CRC cells as wild-type (HCT-116 WT) or p53-deficient (HCT-116 p53-/-) were cultured using multicellular tumor microenvironment (TME) cultures containing T-lymphocytes and fibroblasts to elucidate the role of p53/Sirt-1 modulation in resveratrol's concentration-dependent, pro-apoptotic, and thus anti-cancer effects. Results: Resveratrol dose-dependently inhibited viability, proliferation, plasticity as well as migration, and induced apoptosis in HCT-116 WT more effectively than in HCT-116 p53-/- cells. Moreover, resveratrol stimulated Sirt-1 expression when administered at low concentrations (<5µM) but suppressed it when added at high concentrations (>10µM) to CRC-TME. In parallel, similar to the knockdown of Sirt-1 at the mRNA level, treatment with high-concentration resveratrol boosted the acetylation of p53, the expression of p21, Bax, cytochrome C, caspase-3, and ultimately induced apoptosis in CRC WT but not in CRC p53-/- cells. Notably, increasing concentrations of resveratrol were found to promote hyperacetylation of p53 and FOXO3a as post-translational substrates of Sirt-1, indicating a negative regulatory loop between Sirt-1 and p53. Discussion: These results demonstrate for the first time, a negative reciprocal crosstalk between the regulatory circuits of p53 and Sirt-1, consequently, apoptosis induction by higher resveratrol concentrations in CRC-TME.

Ligustilide, a novel SIRT1 agonist, alleviates lipopolysaccharide-induced acute lung injury through deacetylation of NICD.

Development and progression of sepsis-induced acute lung injury (ALI) involve apoptosis and oxidative stress in lung epithelial cells. Ligustilide (LIG) is one of the main bioactive constituents derived from the Angelica sinensis. As a novel SIRT1 agonist, LIG owns powerful anti-inflammatory and antioxidative properties, exerting remarkable therapeutic effects on cancers, neurological disorders, and diabetes mellitus. However, whether LIG could protect against lipopolysaccharide (LPS)-induced ALI by activating SIRT1 remains unclear. Mice underwent intratracheal LPS injection to mimic sepsis-induced ALI while MLE-12 cells were treated with LPS for 6 h to establish an in vitro ALI model. At the same time, mice or MLE-12 cells were treated with different doses of LIG to access its pharmacological effect. The results demonstrated that LIG pretreatment could improve LPS-induced pulmonary dysfunction and pathological injury, apart from increasing 7-day survival rate. In addition, LIG pretreatment also decreased inflammation, oxidative stress and apoptosis during LPS-induced ALI. Mechanically, LPS stimulation decreased the expression and activity of SIRT1 but increased the expression of Notch1 and NICD. And LIG could also enhance the interaction between SIRT1 and NICD, thus deacetylating NICD. In vitro experiments also unveiled that EX-527, a selective SIRT1 inhibitor, could abolish LIG-elicited protection in LPS-treated MLE-12 cells. And in SIRT1 knockout mice with ALI, LIG pretreatment also lost its effects on inflammation, apoptosis, and oxidative stress during ALI.

Naringin against doxorubicin-induced hepatotoxicity in mice through reducing oxidative stress, inflammation, and apoptosis via the up-regulation of SIRT1.

Clinical application of doxorubicin is limited because of its potential side effects. The present study examined whether naringin had protective actions on doxorubicin-induced liver injury. Male BALB/c mice and alpha mouse liver 12 (AML-12) cells were used in this paper. The results showed that AML-12 cells treated with naringin significantly reduced cell injury, reactive oxygen species release and apoptosis level; Moreover, naringin notably alleviated liver injury by decreasing aspartate transaminase, alanine transaminase and malondialdehyde, and increasing superoxide dismutase, glutathione and catalase levels. Mechanism researches indicated that naringin increased the expression levels of sirtuin 1 (SIRT1), and inhibited the downstream inflammatory, apoptotic and oxidative stress signaling pathways. Further validation was obtained by knocking down SIRT1 in vitro, which proved the effects of naringin on doxorubicin-induced liver injury. Therefore, naringin is a valuable lead compound for preventing doxorubicin-induced liver damage by reducing oxidative stress, inflammation, and apoptosis via up-regulation of SIRT1.

Rosmarinic acid mitigates chlorpyrifos-induced oxidative stress, inflammation, and kidney injury in rats by modulating SIRT1 and Nrf2/HO-1 signaling.

Chlorpyrifos (CPF) is a widely used broad-spectrum pesticide with multi-organ toxic effects. Oxidative stress was found to play a role in the deleterious effects of CPF, including nephrotoxicity. This study investigated the protective effect of the antioxidant polyphenol rosmarinic acid (RA) against CPF-induced kidney injury, with an emphasis on oxidative injury, inflammation, SIRT1, and Nrf2/HO-1 signaling. Rats received 10 mg/kg CPF and 25, 50, and 100 mg/kg RA orally for 28 days, and the samples were collected for analysis. CPF increased serum urea and creatinine and kidney Kim-1 and caused several histopathological alterations. ROS, MDA, NO, NF-κB p65, TNF-α, and IL-1ß were elevated in the kidney of CPF-intoxicated rats. RA ameliorated kidney function markers, prevented tissue injury, suppressed ROS, MDA, and NO, and downregulated NF-κB p65, TNF-α, and IL-1ß in CPF-intoxicated rats in a dose-dependent manner. RA decreased Bax, caspase-3, oxidative DNA damage, and Keap1, boosted antioxidant enzymes and Bcl-2, and upregulated Nrf2, HO-1, and SIRT1 in CPF-administered rats. Molecular docking simulation revealed the binding affinity of RA toward NF-κB, Keap1, HO-1, and SIRT1. In conclusion, RA prevented CPF nephrotoxicity by attenuating oxidative stress, inflammation, and apoptosis and upregulating SIRT1 and Nrf2/HO-1 signaling.

Bergenin has neuroprotective effects in mice with ischemic stroke through antioxidative stress and anti-inflammation via regulating Sirt1/FOXO3a/NF-κB signaling.

OBJECTIVE: Bergenin (BGN) is a C-glycoside of 4-O-methylgallic acid with anti-inflammatory, antioxidant, and tissue-repairing abilities. Here, we probed the roles and mechanisms of BGN in ischemic stroke-mediated cerebral injury. METHODS: The middle cerebral artery occlusion (MCAO) model was established in mice, which were injected intraperitoneally with varying concentrations of BGN (10, 20, and 40 mg/kg). The modified neurological severity score (mNSS) and the water maze experiment were adopted to evaluate mice's neural functions (movement and memory). The brain edema was assessed by the dry and wet method. TdT-mediated dUTP nick end labeling (TUNEL)-labeled apoptotic neurons and Iba1-labeled microglia in the cortex were measured by immunohistochemistry (IHC). Quantitative reverse transcription-PCR and ELISA were implemented to determine the expression of inflammatory cytokines (TNFα, IL-1ß, and IL-6), neurotrophic factors (BDNF and VEGF), and oxidative stress factors (SOD and MDA) in brain tissues. The profiles of Sirt1, FOXO3a, Nrf2, NF-κB, and STAT6 in brain tissues were checked by western blot. RESULTS: BGN significantly improved MCAO mice's cognitive, learning, and motor functions, reduced brain edema, hampered the production of inflammatory factors and oxidative stress mediators, and suppressed neuronal apoptosis. Additionally, BGN dampened the expression of proinflammatory cytokines and upregulated neurotrophic factors and oxidative stress factors in ischemic brain tissues of MCAO mice. Meanwhile, BGN reduced the expression of inflammatory cytokines and oxidative stressors in oxygen-glucose deprivation/reoxygenation-induced BV2 microglia. Further mechanistic studies revealed that BGN concentration dependently elevated the profiles of Sirt1, FOXO3a, STAT6, and Nrf2, and abated the NF-κB phosphorylation. CONCLUSION: BGN protects against ischemic stroke in mice by boosting the Sirt1/FOXO3a pathway, suggesting its potential as a therapeutic agent for ischemic stroke.

In vitro antiaging activity of polyphenol rich Polyalthia longifolia (Annonaceae) leaf extract in Saccharomyces cerevisiae BY611 yeast cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Polyalthia longifolia var. angustifolia Thw. (Annonaceae) is commonly used in traditional medicine as a tonic for rejuvenation and exhibiting good antioxidant activities. AIM OF THE STUDY: To evaluate P. longifolia methanolic leaf extract (PLME) antiaging activity at 1 mg/mL in Saccharomyces cerevisiae BY611 yeast. MATERIALS AND METHODS: The antiaging effect of PLME was studied via replicative lifespan assay, antioxidative stress assays, reactive oxygen species (ROS) determination, reduced glutathione (GSH) determination, superoxide dismutase (SOD) and Sirtuin 1 (SIRT1) genes regulation studies and SOD and SIRT1 proteins activities. RESULTS: The PLME treatment increased the growth and prolonged the lifespan of the yeast significantly (p < 0.05) compared to the untreated yeast group. Besides, the PLME also protected the yeast from oxidative stress induced by 4-mM-H2O2 via decreasing (p < 0.05) the ROS from 143.207 to 127.223. The antioxidative action of PLME was proved by spot assay. Phloxine B staining was further confirmed the PLME antioxidative action of PLME, where more whitish-pink live yeast cells were observed. In addition, the PLME also enhanced GSH content significantly (p < 0.05) in yeast treated with PLME from 16.81 to 25.31 µmol. Furthermore, PLME increased the SOD and SIRT1 genes expression significantly (p < 0.05) with ΔCt values of 1.11 and 1.15, respectively. The significantly (p < 0.05) elevated SOD and SIRT1 protein activities were recorded as 51.54 U/mg Prot and 1716 ng/mL, respectively. CONCLUSIONS: PLME exhibited good antiaging activities in S. cerevisiae, by modulating oxidative stress, enhancing GSH content, and increasing SOD and SIRT1 genes expression.

Nicotinamide mononucleotide increases cell viability and restores tight junctions in high-glucose-treated human corneal epithelial cells via the SIRT1/Nrf2/HO-1 pathway.

BACKGROUND: Diabetes mellitus (DM)-related corneal epithelial dysfunction is a severe ocular disorder; however, the effects of nicotinamide mononucleotide (NMN) on high-glucose (HG)-treated human corneal epithelial cells (HCECs) remain unclear. METHODS: We conducted an in-vitro study to examine the effects of NMN treatment on HG-treated HCECs. Cell viability was measured using trypan blue stain, mitochondrial membrane potential was measured using JC-1 stain, and intracellular reactive oxygen species and apoptosis assays were conducted using flow cytometry. Transepithelial electrical resistance (TEER) and zonula occludens-1 (ZO-1) immunofluorescence for tight junction examinations were conducted. Immunoblot analyses were conducted to analyze the expression of silent information regulator-1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) of the SIRT1/Nrf2/HO-1 pathway. RESULTS: NMN increased cell viability by reducing cell damage, reducing apoptosis, increasing cell migration, and restoring tight junctions in HG-treated HCECs. By analyzing the expressions of SIRT1, Nrf2, HO-1, NMN demonstrated protective effects via the SIRT1/Nrf2/HO-1 pathway. CONCLUSIONS: NMN increases cell viability by reversing cell damage, reducing apoptosis, increasing cell migration, and restoring tight junctions in HG-treated HCECs, and these effects may be mediated by the SIRT1/Nrf2/HO-1 pathway.

Effects of Stevia rebaudiana Bertoni extracts in the rat model of epilepsy induced by pentylenetetrazol: Sirt-1, at the crossroads between inflammation and apoptosis.

The current study investigated the effects of stevia extracts on a PTZ-induced epileptic rat model and its potential mechanism. Thirty male Sprague-Dawley rats were equally subdivided into 3 groups; (1) normal control (NC) group, (2) PTZ-group: received PTZ (50 mg/kg, i.p. every other day) for 2 weeks, and (3) PTZ+ Stevia group: received PTZ and stevia (200 mg/kg orally daily) for 4 weeks (2 weeks before the start of PTZ treatment and 2 weeks with PTZ administration). The first jerk latency and the seizure score were assessed in rats. Also, brain tissue samples were collected by the end of the experiment, and oxidative stress markers (catalase, MDA, and total antioxidant capacity (TAC)) were measured by biochemical analysis in hippocampal brain homogenates. Also, in the hippocampus, the expression of IL6 and Bcl-2 at the mRNA level and expression of Sirt-1, P53, caspase-3, GFAP, and NF-kB in CA3 hippocampal region by immunohistochemistry was investigated. PTZ substantially increased the seizure score and decreased the seizure latency. Also, PTZ significantly increased MDA, GFAP, IL-6, NF-kB, caspase-3, and p53 and significantly reduced Sirt-1, TAC, and Bcl-2 in hippocampal tissues compared to the control group (p < 0.01). However, Stevia Rebaudiana Bertoni (Stevia R.) significantly attenuated the PTZ-induced seizures, improved oxidative stress markers, downregulated GFAP, IL-6, NF-kB, caspase-3, and p53, and upregulated Sirt-1 and Bcl-2 in the CA3 hippocampal region (p < 0.01). In conclusion, Stevia R. exhibits neuroprotective and antiepileptic actions in PTZ-induced epilepsy due to its antioxidant, anti-apoptotic, and anti-inflammatory effects. Additionally, the Sirt-1 pathway might be involved in the antiepileptic and neuroprotective effects of stevia in PTZ-kindled epileptic rat model.

Flavonostilbenes Isolated from the Stems of Rhamnoneuron balansae as Potential SIRT1 Activators.

The cumulative effects of cell damage result in aging, which gradually decreases human function in various aspects and leads to multiple age-related chronic diseases. To overcome the adverse effects of aging, silent mating type information regulation 2 homologue (SIRT1) activators are promising bioactive compounds that mimic calorie restriction to improve quality of life and prevent aging. In this study, 11 new flavonostilbenes (1-11) and three known compounds (12-14) were purified from stems of Rhamnoneuron balansae. The structures of the new compounds were determined using extensive data from spectroscopic methods, including NMR and HRESIMS. Their absolute configurations were deduced by ECD calculations with coupling constant analysis. All of the isolated new compounds (1-11) were evaluated for their effects on SIRT1 deacetylase activity, the NAD+/NADH ratio, and the AMP-activated protein kinase activation level in cell-based assays. The results showed that rhamnoneuronal D (1) exhibits promising biological activity in several in vitro models related to SIRT1 and suggest it is a potential natural-product-based antiaging agent.

Neuroprotective effects of indole-3-carbinol on the rotenone rat model of Parkinson's disease: Impact of the SIRT1-AMPK signaling pathway.

Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder. Although mounting studies have been conducted, no effective therapy is available to halt its progression. Indole-3-carbinol (I3C) is a naturally occurring compound obtained by ß-thioglucosidase-mediated autolysis of glucobrassicin in cruciferous vegetables. Besides its powerful antioxidant activity, I3C has shown neuroprotection against depression and chemically induced neurotoxicity via its anti-inflammatory and antiapoptotic effects. This study aimed to investigate the neuroprotective effects of I3C against rotenone (ROT)-induced PD in male albino rats. The possible protective mechanisms were also explored. PD was induced by subcutaneous administration of ROT (2 mg/kg) for 28 days. The effects of I3C (25, 50, and 100 mg/kg/day) were assessed by catalepsy test (bar test), spontaneous locomotor activity, rotarod test, weight change, tyrosine hydroxylase (TH) expression, α-synuclein (α-Syn) expression, striatal dopamine (DA) content, and histological examination. The highest dose of I3C (100 mg/kg) was the most effective to prevent ROT-mediated motor dysfunctions and amend striatal DA decrease, weight loss, neurodegeneration, TH expression reduction, and α-Syn expression increase in both the midbrain and striatum. Further mechanistic investigations revealed that the neuroprotective effects of I3C are partially attributed to its anti-inflammatory and antiapoptotic effects and the activation of the sirtuin 1/AMP-activated protein kinase pathway. Altogether, these results suggested that I3C could attenuate biochemical, molecular, and functional changes in a rat PD model with following repeated rotenone exposures.

High concentration of hydrogen ameliorates lipopolysaccharide-induced acute lung injury in a sirt1-dependent manner.

The aim of this study was to investigate the efficacy and underlying mechanism of high concentration of hydrogen on lipopolysaccharide (LPS)-induced acute lung injury (ALI). We have established a corresponding mouse model and examined the function of hydrogen inhalation on lung pathology and pulmonary edema induced by LPS, as well as contents of IL-1ß, TNF-α and IL-8. The pulmonary microvascular permeability and 66.7 % hydrogen on the expression of sirt1 and its downstream signaling molecules were tested. Results showed that 66.7 % hydrogen alleviated lung pathological changes and pulmonary edema caused by LPS, and reduced the degree of ALI by inhibiting pro-inflammatory cytokine release and oxidative stress response, thereby decreasing the expression of molecules related to intercellular adhesion. sirt1 contributed to the repair of LPS-induced ALI by hydrogen through the regulation of NF-κB and catalase expression. In conclusion, 66.7 % hydrogen protected against LPS-induced ALI by suppressing inflammatory response and oxidative stress mediated by NF-κB and catalase in a sirt1-dependent manner.

Ovatodiolide protects ischemia-reperfusion-induced neuronal injury via microglial neuroinflammation via mediating SIRT1/NF-κB pathway.

BACKGROUND: Ovatodiolide (OVA), a bioactive substance extracted from the bioactive component of Anisomeles indica, is reported to be endowed with anti-inflammatory properties. Nonetheless, its function in ischemia-reperfusion (I/R)-induced neurological deficits and microglial inflammation remains unclear. METHOD: A middle cerebral artery occlusion (MCAO) model was set up in SD rats, which were then dealt with varying doses of OVA. The rats' neurological functions were estimated at diverse periods postoperatively. The dry and wet method, triphenyl tetrazolium chloride (TTC) staining, and Nissl's staining were conducted to measure brain edema, cerebral infarction area and neuronal damage, respectively. Immunohistochemistry (IHC) was performed to detect neuronal apoptosis and microglial activation, and the profiles of inflammatory factors in the cerebral tissues were estimated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). In-vitro assays were implemented on HT22 neuronal cells and BV2 microglia to elaborate the effect of OVA against oxygen-glucose deprivation (OGD)-mediated effects. RESULTS: OVA relieved HT22 cell apoptosis and eased inflammation in BV2 microglia, which were induced by OGD. OVA mitigated NF-κB phosphorylation in BV2 cells, whereas boosted SIRT1 expression. However, inhibiting SIRT1 abolished the anti-inflammatory effects of OVA in BV2 microglia under OGD stimulation. The condition medium (CM) of OGD-treated BV2 cells enhanced HT22 cell apoptosis and damage. OVA treatment in BV2 cells relieved BV2-mediated injury on HT22 cells, which was reversed by SIRT1 inhibitor. In-vivo results revealed that OVA dose-dependently attenuated I/R rats' neurological deficits, reduced brain edema, cerebral infarction area, neuronal apoptosis and microglial overactivation. Additionally, OVA inactivated the NF-κB pathway and up-regulated SIRT1 in the I/R rat model. CONCLUSION: OVA prevented rats from brain I/R damage by hampering neuronal apoptosis and microglial inflammation via the SIRT1-NF-κB pathway. DATA AVAILABILITY: The data sets used and analyzed during the current study are available from the corresponding author on reasonable request.

Isoliquiritigenin prevents Doxorubicin-induced hepatic damage in rats by upregulating and activating SIRT1.

This study evaluated if the hepatic protective effect of Isoliquiritigenin (ISL) against doxorubicin (DOX)-treated rats involves upregulating sirtuin-1 (SIRT1) signaling. Adult male was divides into 5 groups (n = 6 rats/each) as control (vehicle), ISL (25 mg/kg), DOX (15 mg/kg), DOX + ISL, and DOX + ISL + EX-527 (a SIRT1 inhibitor, 5 mg/kg). ISL and EX-527 were administered 10 days before and after the single treatment of DOX. Also, cultured AML-12 hepatocytes (5 ×104) were treated with 10 µM of ISL for 24 h with or without DOX-treatments (10 µM) and in the presence or absence of EX-527 (5 µM). ISL prevented hepatocyte damage and decreased serum levels of hepatic transaminases, hepatic levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and hepatic mRNA levels of Bax and caspases-3,8, and 9. In the liver of the control and DOX-treated rats, ISL reduced levels of malondialdehyde (MDA) but increased hepatic levels of glutathione (GSH), superoxide dismutase (SOD), and catalase, as well as mRNA levels of Bcl2. In vitro, ISL stimulated cell survival and lowered levels of ROS but increased GSH levels. In vivo and in vitro, in the livers of control and DOX-treated animals, ISL significantly increased the nuclear activity and mRNA levels of SIRT1, enhanced the nuclear levels of Nrf2, and reduced nuclear levels of NF-κB p65. In conclusion, ISL alleviates DOX-induced hepatocyte toxicity by stimulating the Nrf2/antioxidants axis and concomitant suppression of NF-κB, mainly by upregulating/activating SIRT1.

Melatonin enhances SIRT1 to ameliorate mitochondrial membrane damage by activating PDK1/Akt in granulosa cells of PCOS.

Mitochondrial injury in granulosa cells (GCs) is associated with the pathophysiological mechanism of polycystic ovary syndrome (PCOS). Melatonin reduces the mitochondrial injury by enhancing SIRT1 (NAD-dependent deacetylase sirtuin-1), while the mechanism remains unclear. Mitochondrial membrane potential is a universal selective indicator of mitochondrial function. In this study, mitochondrial swelling and membrane defect mitochondria in granulosa cells were observed from PCOS patients and DHT-induced PCOS-like mice, and the cytochrome C level in the cytoplasm and the expression of BAX (BCL2-associated X protein) in mitochondria were significantly increased in GCs, with p-Akt decreased, showing mitochondrial membrane was damaged in GCs of PCOS. Melatonin treatment decreased mitochondrial permeability transition pore (mPTP) opening and increased the JC-1 (5,5',6,6'-tetrachloro1,1',3,3'-tetramethylbenzimidazolylcarbocyanine iodide) aggregate/monomer ratio in the live KGN cells treated with DHT, indicating melatonin mediates mPTP to increase mitochondrial membrane potential. Furthermore, we found melatonin decreased the levels of cytochrome C and BAX in DHT-induced PCOS mice. PDK1/Akt played an essential role in improving the mitochondrial membrane function, and melatonin treatment increased p-PDK 1 and p-Akt in vivo and in vitro. The SIRT1 was also increased with melatonin treatment, while knocking down SIRT1 mRNA inhibiting the protective effect of melatonin to activate PDK1/Akt. In conclusion, melatonin enhances SIRT1 to ameliorate mitochondrial membrane damage by activating PDK1/Akt in granulosa cells of PCOS.

Downregulation of miR-128 Ameliorates Ang II-Induced Cardiac Remodeling via SIRT1/PIK3R1 Multiple Targets.

Recent studies reported that miR-128 was differentially expressed in cardiomyocytes in response to pathologic stress. However, its function and mechanism remain to be fully elucidated. The aim of the present study was to investigate the role of miR-128 in chronic angiotensin II (Ang II) infusion-induced cardiac remodeling and its underlying mechanism. The cardiac remodeling and heart failure in vivo were established in C57BL/6 mice by chronic subcutaneous Ang II delivery. Knocking down miR-128 was conducted in the hearts of the mice by intravenous injection of HBAAV2/9-miR-128-GFP sponge (miR-128 inhibitor). In vitro experiments of cardiac hypertrophy, apoptosis, and aberrant autophagy were performed in cultured cells after Ang II treatment or transfection of miR-128 antagomir. Our results showed that chronic Ang II delivery for 28 days induced cardiac dysfunction, hypertrophy, fibrosis, apoptosis, and oxidative stress in the mice, while the miR-128 expression was notably enhanced in the left ventricle. Silencing miR-128 in the hearts of mice ameliorated Ang II-induced cardiac dysfunction, hypertrophy, fibrosis apoptosis, and oxidative stress injury. Moreover, Ang II induced excessive autophagy in the mouse hearts, which was suppressed by miR-128 knockdown. In cultured cells, Ang II treatment induced a marked elevation in the miR-128 expression. Downregulation of miR-128 in the cells by transfection with miR-128 antagomir attenuated Ang II-induced apoptosis and oxidative injury probably via directly targeting on the SIRT1/p53 pathway. Intriguingly, we found that miR-128 inhibition activated PIK3R1/Akt/mTOR pathway and thereby significantly damped Ang II-stimulated pathological autophagy in cardiomyocytes, which consequently mitigated cell oxidative stress and apoptosis. In conclusion, downregulation of miR-128 ameliorates Ang II-provoked cardiac oxidative stress, hypertrophy, fibrosis, apoptosis, and dysfunction in mice, likely through targeting on PIK3R1/Akt/mTORC1 and/or SIRT1/p53 pathways. These results indicate that miR-128 inhibition might be a potent therapeutic strategy for maladaptive cardiac remodeling and heart failure.

Activation of SIRT1 by Resveratrol Alleviates Pressure Overload-Induced Cardiac Hypertrophy via Suppression of TGF-ß1 Signaling.

INTRODUCTION: Silent information regulator 1 (SIRT1) has been extensively investigated in the cardiovascular system and has been shown to play a pivotal role in mediating cell death/survival, energy production, and oxidative stress. However, the functional role of SIRT1 in pressure overload-induced cardiac hypertrophy and dysfunction remains unclear. Resveratrol (Rsv), a widely used activator of SIRT1, has been reported to protect against cardiovascular disease. We here examine whether activation of SIRT1 by Rsv attenuate pressure overload-induced cardiac hypertrophy and to identify the underlying molecular mechanisms. METHODS: In vivo, rat model of pressure overload-induced myocardial hypertrophy was established by abdominal aorta constriction (AAC) procedure. In vitro, Angiotensin II (Ang II) was applied to induce hypertrophy in cultured neonatal rat cardiomyocytes (NCMs). Hemodynamics and histological analyses of the heart were evaluated. The expression of SIRT1, transforming growth factor-ß1 (TGF-ß1)/phosphorylated (p)-small mother against decapentaplegic (Smad)3 and hypertrophic markers were determined by immunofluorescence, real-time PCR, and Western blotting techniques. RESULTS: In the current study, Rsv treatment improved left ventricular function and reduced left ventricular hypertrophy and cardiac fibrosis significantly in the pressure overload rats. The expression of SIRT1 was significantly reduced, while the expression of TGF-ß1/p-Smad3 was significantly enhanced in AAC afflicted rat heart. Strikingly, treatment with Rsv restored the expressions of SIRT1 and TGF-ß1/p-Smad3 under AAC influence. However, SIRT1 inhibitor Sirtinol (Snl) markedly prevented the effects of Rsv, which suggest that SIRT1 signaling pathway was involved in the cardiac protective effect of Rsv. In vitro studies performed in Ang II-induced hypertrophy in NCMs confirmed the cardiac protective effect of Rsv. Furthermore, the study presented that SIRT1 negatively correlated with the cardiac hypertrophy, cardiac fibrosis, and the TGF-ß1/p-Smad3 expression. CONCLUSIONS: Taken together, these results indicated that activation of SIRT1 by Rsv attenuates cardiac hypertrophy, cardiac fibrosis, and improves cardiac function possibly via regulation of the TGF-ß1/p-Smad3 signaling pathway. Our study may provide a potential therapeutic strategy for cardiac hypertrophy.