T-2 toxin induces cardiac fibrosis by causing metabolic disorders and up-regulating Sirt3/FoxO3α/MnSOD signaling pathway-mediated oxidative stress.

T-2 toxin, an omnipresent environmental contaminant, poses a serious risk to the health of humans and animals due to its pronounced cardiotoxicity. This study aimed to elucidate the molecular mechanism of cardiac tissue damage by T-2 toxin. Twenty-four male Sprague-Dawley rats were orally administered T-2 toxin through gavage for 12 weeks at the dose of 0, 10, and 100 nanograms per gram body weight per day (ng/(g·day)), respectively. Morphological, pathological, and ultrastructural alterations in cardiac tissue were meticulously examined. Non-targeted metabolomics analysis was employed to analyze alterations in cardiac metabolites. The expression of the Sirt3/FoxO3α/MnSOD signaling pathway and the level of oxidative stress markers were detected. The results showed that exposure to T-2 toxin elicited myocardial tissue disorders, interstitial hemorrhage, capillary dilation, and fibrotic damage. Mitochondria were markedly impaired, including swelling, fusion, matrix degradation, and membrane damage. Metabonomics analysis unveiled that T-2 toxin could cause alterations in cardiac metabolic profiles as well as in the Sirt3/FoxO3α/MnSOD signaling pathway. T-2 toxin could inhibit the expressions of the signaling pathway and elevate the level of oxidative stress. In conclusion, the T-2 toxin probably induces cardiac fibrotic impairment by affecting amino acid and choline metabolism as well as up-regulating oxidative stress mediated by the Sirt3/FoxO3α/MnSOD signaling pathway. This study is expected to provide targets for preventing and treating T-2 toxin-induced cardiac fibrotic injury.

Polydatin: a potential NAFLD therapeutic drug that regulates mitochondrial autophagy through SIRT3-FOXO3-BNIP3 and PINK1-PRKN mechanisms - a network pharmacology and experimental investigation.

Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disorder that is linked to metabolic syndrome, mitochondrial dysfunction and impaired autophagy. Polydatin (PD), a natural polyphenol from Polygonum cuspidatum, exhibits various pharmacological effects and protects against NAFLD. The aim of this study was to reveal the molecular mechanisms and therapeutic potential of PD for NAFLD, with a focus on the role of mitochondrial autophagy mediated by sirtuin 3 (SIRT3), fork-head box O3 (FOXO3) and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), and by PTEN-induced putative kinase 1 (PINK1) and parkin (PRKN). We combined network pharmacology analysis, animal models and cell culture experiments to show that PD could regulate the mitochondrial autophagy pathway by modulating several key genes related to mitochondrial function, and ameliorate the liver function, histopathology and mitochondrial biogenesis of NAFLD mice and hepatocytes by activating the SIRT3-FOXO3-BNIP3 axis and the PINK1-PRKN-dependent mechanism of mitochondrial autophagy. We also identified the core targets of PD, including SIRT3, FOXO3A, CASP3, PARKIN, EGFR, STAT3, MMP9 and PINK, and confirmed that silencing SIRT3 could significantly attenuate the beneficial effect of PD. This study provided novel theoretical and experimental support for PD as a promising candidate for NAFLD treatment, and also suggested new avenues and methods for investigating the role of mitochondrial autophagy in the pathogenesis and intervention of NAFLD.

Resveratrol protects against myocardial ischemic injury in obese mice via activating SIRT3/FOXO3a signaling pathway and restoring redox homeostasis.

BACKGROUND: Increasing global overweight and obesity rates not only increase the prevalence of myocardial infarction (MI), but also exacerbate ischemic injury and result in worsened prognosis. Currently, there are no drugs that can reverse myocardial damage once MI has occurred, therefore discovering drugs that can potentially limit the extent of ischemic damage to the myocardium is critical. Resveratrol is a polyphenol known for its antioxidant properties, however whether prolonged daily intake of resveratrol during obesity can protect against MI-induced damage remains unexplored. METHODS: We established murine models of obesity via high-fat/high-fructose diet, along with daily administrations of resveratrol or vehicle, then performed surgical MI to examine the effects and mechanisms of resveratrol in protecting against myocardial ischemic injury. RESULTS: Daily administration of resveratrol in obese mice robustly protected against myocardial ischemic injury and improved post-MI cardiac function. Resveratrol strongly inhibited oxidative and DNA damage via activating SIRT3/FOXO3a-dependent antioxidant enzymes following MI, which were completely prevented upon administration of 3-TYP, a selective SIRT3 inhibitor. Hence, the cardioprotective effects of prolonged resveratrol intake in protecting obese mice against myocardial ischemic injury was due to reestablishment of intracellular redox homeostasis through activation of SIRT3/FOXO3a signaling pathway. CONCLUSION: Our findings provide important new evidence that supports the daily intake of resveratrol, especially in those overweight or obese, which can robustly decrease the extent of ischemic damage following MI. Our study therefore provides new mechanistic insight and suggests the therapeutic potential of resveratrol as an invaluable drug in the treatment of ischemic heart diseases.

A new andrographolide derivative ADA targeting SIRT3-FOXO3a signaling mitigates cognitive impairment by activating mitophagy and inhibiting neuroinflammation in Apoe4 mice.

BACKGROUND: Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and mitophagy deficit was identified as the typical abnormality in early stage of AD. The neuroprotective effect of andrographolide (AGA) has been confirmed, anda acetylated derivative of AGA (3,14,19-triacetylandrographolide, ADA) was considered to have stronger efficacy. PURPOSE: The current study aims to investigate the impact of ADA on cognitive ability in a sporadic AD model and explore its potential mechanism. STUDY DESIGN/ METHODS: Apoe4 mouse was adopted for evaluating the impact of AGA on cognitive impairment through a serious of behavioral tests. The molecular mechanism of ADA involved in mitophagy and neuroinflammation was investigated in detailby Western blot, ELISA, immunofluorescence and transmission electron microscopy in Apoe4 mice, as well as Apoe4-transfected BV2 cells and HT22 cells. RESULTS: ADA application significantly improved cognitive impairment of Apoe4 mice, and lessened Aß load and neuronal damage, which has stronger activity than its prototype AGA. Accumulated mitophagy markers LC3II, P62, TOM20, PINK1 and Parkin, and decreased mitophagy receptor BNIP3 in hippocampus of Apoe4 mice were greatly reversed after ADA treatment. Meanwhile, ADA promoted the recruitment of BNIP3 to mitochondria, and the transport of damaged mitochondria to lysosome, indicating that disturbed mitophagy in AD mice was restored by ADA. Inhibited SIRT3 and FOXO3a in Apoe4 mice brains were elevated after ADA treatment. ADA also lightened the neuroinflammation caused by NLRP3 inflammasome activation. Additionally, damaged mitophagy and/or activated NLRP3 inflammasome were also observed in BV2 cells and HT22 cells transfected with Apoe4, all of which were rescued by ADA incubation. Noteworthily, SIRT3 inhibitor 3-TYP could abolish the impact of ADA on mitophagy and NLRP3 inflammasome in vitro. CONCLUSION: ADA exerted stronger cognition-enhancing ability in relative to AGA, and ADA could repaire mitophagy deficiency via SIRT3-FOXO3a pathway, and subsequently inhibite NLRP3 inflammasome to mitigate AD pathology.

Melatonin alleviates pyroptosis by regulating the SIRT3/FOXO3α/ROS axis and interacting with apoptosis in Atherosclerosis progression.

BACKGROUND: Atherosclerosis (AS), a significant contributor to cardiovascular disease (CVD), is steadily rising with the aging of the global population. Pyroptosis and apoptosis, both caspase-mediated cell death mechanisms, play an essential role in the occurrence and progression of AS. The human pineal gland primarily produces melatonin (MT), an indoleamine hormone with powerful anti-oxidative, anti-pyroptotic, and anti-apoptotic properties. This study examined MT's anti-oxidative stress and anti-pyroptotic effects on human THP-1 macrophages treated with nicotine. METHODS: In vitro, THP-1 macrophages were induced by 1 µM nicotine to form a pyroptosis model and performed 30 mM MT for treatment. In vivo, ApoE-/- mice were administered 0.1 mg/mL nicotine solution as drinking water, and 1 mg/mL MT solution was intragastric administrated at 10 mg/kg/day. The changes in pyroptosis, apoptosis, and oxidative stress were detected. RESULTS: MT downregulated pyroptosis, whose changes were paralleled by a reduction in reactive oxygen species (ROS) production, reversal of sirtuin3 (SIRT3), and Forkhead box O3 (FOXO3α) upregulation. MT also inhibited apoptosis, mainly caused by the interaction of caspase-1 and caspase-3 proteins. Vivo studies confirmed that nicotine could accelerate plaque formation. Moreover, mice treated with MT showed a reduction in AS lesion area. CONCLUSIONS: MT alleviates pyroptosis by regulating the SIRT3/FOXO3α/ROS axis and interacting with apoptosis. Importantly, our understanding of the inhibitory pathways for macrophage pyroptosis will allow us to identify other novel therapeutic targets that will help treat, prevent, and reduce AS-associated mortality.

Resveratrol reduces ROS-induced ferroptosis by activating SIRT3 and compensating the GSH/GPX4 pathway.

BACKGROUND: Intestinal ischemia-reperfusion injury occurs in acute intestinal obstruction, intussusception, acute mesenteric artery embolism, and other diseases and can lead to local intestinal necrosis, distant organ involvement, or systemic reactions, with high morbidity and mortality. Ferroptosis plays a crucial role in intestinal ischemia-reperfusion injury, and inhibition of ferroptosis may provide new approaches for treating the disease. SIRT3 protects cells from oxidative stress and may be involved in the process of ferroptosis. We hypothesized that resveratrol, an agonist of SIRT3, could ameliorate intestinal ischemia-reperfusion injury by compensating the GSH/GPX4 pathway. METHODS: Intestinal ischemia-reperfusion (I/R) and Caco-2 hypoxia-reoxygenation models were established. Transmission electron microscopy was used to assess mitochondrial function; the Chiu's score was used to evaluate the degree of intestinal mucosal injury based on HE staining; and Western blot was used to detect the SIRT3/FoxO3a pathway, tight junction proteins and ferroptosis-related protein expression. Sirt3-/- C57, shSIRT3-Caco-2 cells and siFoxO3a-Caco-2 cells were established. C11-BODIPY was used to detect lipid peroxide in cells; FD4 and IFABP were used to detect intestinal permeability; MitoSOX was used to detect ROS levels; and MitoTracker and immunofluorescence colocalization were used to detect SIRT3 levels. RESULTS: In the intestinal I/R model, I/R injury occurs mainly during the reperfusion period and leads to ferroptosis through the GSH/GPX4 pathway. Resveratrol could reduce ferroptosis and ameliorate I/R injury by activating SIRT3. In Sirt3-/- mice, more intestinal mucosal cells underwent ferroptosis, I/R injury was more severe, and resveratrol lost the ability to ameliorate I/R injury. In addition, hypoxia-reoxygenation increased RSL3-induced ferroptosis sensitivity in Caco-2 cells in vitro. In the presence of shSIRT3 or RSL3 alone, resveratrol could ameliorate Caco-2 ferroptosis, but not RSL3-induced shSIRT3-Caco-2 ferroptosis. Furthermore, resveratrol might activate the SIRT3/FoxO3a pathway, increase the expression of SOD2 and catalase, and inhibit ROS generation, thus reducing lipid peroxidation and ferroptosis. CONCLUSION: To date, this is the first study to show that resveratrol ameliorates intestinal ischemia-reperfusion injury by activating SIRT3 and reducing ferroptosis. Resveratrol can reduce intestinal ischemia-reperfusion injury by activating the SIRT3/FoxO3a pathway, increasing the expression of SOD2 and catalase, reducing ROS and LPO production, compensating for the GSH/GPX4 pathway and inhibiting ferroptosis. Resveratrol increases the expression of SOD2 and catalase, reduces the production of ROS and LPO, compensates for the GSH/GPX4 pathway and inhibits ferroptosis by activating the SIRT3/FoxO3a pathway.

Loxenatide attenuates ROS-mediated vascular endothelial progenitor cell damage and mitochondrial dysfunction via SIRT3/Foxo3 signaling pathway.

Diabetes mellitus (DM), becomes a main public health issue worldwide due to the rapid increase in DM patient numbers. The dysfunction of endothelial progenitor cells (EPCs) in DM patients plays a critical role in endothelial repair and the progression of DM-related vascular complications. Loxenatide is an a glucagon-like peptide 1 receptor agonist, which is used to control glycemic in type 2 diabetes patients. However, the role of Loxenatide in EPCs remains to be investigated. EPCs were isolated, characterized, and treated with Loxenatide, high-glucose, or 3-TYP. quantitative real-time polymerase chain reaction, flow cytometry, western blot, and cell counting kit-8 assay were employed to validate the expression of gene and protein expressions and cell viability, respectively. Application of Seahorse XFp to measure oxygen consumption and mitochondrial membrane potential (MMP) were measured by Seahorse XFp and MMP assay. Loxenatide attenuated high-glucose-induced reactive oxygen species (ROS) production and mitochondrial-dependent apoptosis of EPCs in a concentration-dependent manner. The EPC mitochondrial respiration dysfunction induced by high glucose was also repressed by the loxenatide treatment. The protection effect of Loxenatide on EPCs against high-glucose was applied by activating the sirtuin 3 (SIRT3)/Foxo3 signaling pathway. We demonstrated the regulatory role of Loxenatide in mitochondrial dysfunction and apoptosis of EPCs. We elucidated that Loxenatide protects EPC from high-glucose-induced apoptosis via ROS-mediated mitochondrial pathway through the SIRT3/Foxo3 signing pathway. This may provide a new therapeutical target for the treatment of DM-related vascular complications.

Piceatannol alleviate ROS-mediated PC-12 cells damage and mitochondrial dysfunction through SIRT3/FOXO3a signaling pathway.

Oxidative stress-associated mitochondrial dysfunction has been identified as a major mechanism in multiple neurodegenerative diseases. This study aims to investigate the cytoprotective effects of piceatannol on ROS-mediated PC-12 cells damage and related mitochondrial dysfunction. Piceatannol treatment could significantly attenuate PC-12 cells oxidative damage and ROS-mediated cells apoptosis. Moreover, pretreatment with piceatannol effectively decreased mitochondrial membrane depolarization, cleaved-caspase 3, and increased Bcl-2 and Bcl-2/Bax compared with control H2 O2 group. Meanwhile, piceatannol treatment improved mitochondrial respiration function which led to an enhancement in the maximal respiration and spare respiratory capacity. Further mechanisms analysis showed that the protein expression of SIRT3 and its downstream protein FOXO3a were significantly increased after piceatannol addition in a dose-dependent manner. Whereas the cytoprotective role of piceatannol was markedly abolished by the SIRT3 inhibitor 3-TYP, suggesting that SIRT3/FOXO3a signaling pathway played a vital role in mediating the neuronal cytoprotective effects of piceatannol. PRACTICAL APPLICATIONS: The results of our study provide a novel insight that piceatannol could be potentially used as a promising bioactive component against oxidative damage and neurocyte apoptosis. The findings may provide theoretical basis for brain health of piceatannol consumption in some extent.

Sirt3-mediated mitochondrial dysfunction is involved in fluoride-induced cognitive deficits.

Excessive fluoride is capable of inducing cognitive deficits, but the mechanisms remain elusive. This study aimed to investigate the effects and underlying mechanisms of fluoride on mitochondrial dysfunction and neurobiological alterations, as well as cognitive impairment. C57BL/6 mice were orally administered 25, 50, and 100 mg/L NaF for 90 days. Cultured human neuroblastoma SH-SY5Y cells were exposed to NaF (110 mg/L) for 24 h in the presence or absence of Sirt3 overexpression. The results demonstrated that chronic exposure to high fluoride induced cognitive deficits and neural/synaptic injury in mice. Fluoride reduced mitochondrial antioxidant enzyme activities and elevated SOD2 acetylation by downregulating Sirt3 expression in the brains of mice and NaF-treated SH-SY5Y cells. Moreover, fluoride lowered mtDNA transcription and induced mitochondrial dysfunction along with increased FoxO3A acetylation in the brains of mice and NaF-treated SH-SY5Y cells. Subsequent experiments revealed that overexpression of Sirt3 significantly attenuated the adverse effects of fluoride on radical scavenging capabilities and mtDNA transcription, as well as mitochondrial function in SH-SY5Y cells. These results suggest that chronic long-term fluoride exposure evokes neural/synaptic injury and cognitive impairment through mitochondrial dysfunction and its associated oxidative stress, which is, at least partly, mediated by Sirt3 inhibition in the mouse brain.

CD38 Deficiency Protects Heart from High Fat Diet-Induced Oxidative Stress Via Activating Sirt3/FOXO3 Pathway.

BACKGROUND/AIMS: Previous studies showed that CD38 deficiency protected heart from ischemia/reperfusion injury and high fat diet (HFD)-induced obesity in mice. However, the role of CD38 in HFD-induced heart injury remains unclear. In the present study, we have investigated the effects and mechanisms of CD38 deficiency on HFD-induced heart injury. METHODS: The metabolites in heart from wild type (WT) and CD38 knockout (CD38-/-) mice were examined using metabolomics analysis. Cell viability, lactate hydrogenase (LDH) release, super oxide dismutase (SOD) activity, reactive oxygen species (ROS) production, triglyceride concentration and gene expression were examined by biochemical analysis and QPCR. RESULTS: Our results revealed that CD38 deficiency significantly elevated the intracellular glutathione (GSH) concentration and GSH/GSSG ratio, decreased the contents of free fatty acids and increased intracellular NAD+ level in heart from CD38-/- mice fed with HFD. In addition, in vitro knockdown of CD38 significantly attenuated OA-induced cellular injury, ROS production and lipid synthesis. Furthermore, the expression of mitochondrial deacetylase Sirt3 as well as its target genes FOXO3 and SOD2 were markedly upregulated in the H9C2 cell lines after OA stimulation. In contrast, the expressions of NOX2 and NOX4 were significantly decreased in the cells after OA stimulation. CONCLUSION: Our results demonstrated that CD38 deficiency protected heart from HFD-induced oxidative stress via activating Sirt3/FOXO3-mediated anti-oxidative stress pathway.

MicroRNA-421 induces hepatic mitochondrial dysfunction in non-alcoholic fatty liver disease mice by inhibiting sirtuin 3.

BACKGROUND AND AIM: Mitochondrial dysfunction plays a major role in critical initiating or propagating events in nonalcoholic fatty liver disease (NAFLD), but its pathogenesis remains obscure. Recently, microRNAs have been found to affect oxidant stress and lipid metabolism. In this study, we elucidated the functions of microRNA-421 in the development of NAFLD and identified its potential targets. METHODS: An experimental model for the study of NAFLD was constructed by feeding a high fat diet to C57BL/6J mice. Differentially expressed miRNA in livers of NAFLD mice compared with controls were identified by high-throughput sequencing. Relative repression of luciferase expression standardized to a transfection control was analyzed by luciferase reporter assays. RESULTS: The microRNA profiling presented that microRNA-421 expression was significantly upregulated in hepatic tissues of NAFLD model mouse. The sirtuin 3 was identified as a functionally relevant target of microRNA-421. The microRNA-421 acts upstream of SIRT3/FOXO3 pathway in modulation the oxidant stress and lipid metabolism. Overexpression of microRNA-421 decreased SIRT3 and FOXO3 protein levels, and then led to MnSOD and CAT decrease, the downstream targets of SIRT3/FOXO3 pathway. On the contrary, suppression of microRNA-421 had adverse effects on performance of celluar oxidative damage. CONCLUSIONS: Regulating or inhibiting hepatic microRNA-421 could decrease celluar oxidative damage and contribute to therapeutic potential in NAFLD.