Effects of electroacupuncture on Sirt3/NLRP3/GSDMD signaling pathway in the substantia nigra of midbrain of rats with Parkinson's disease. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å¤§é¼ ä¸­è„‘é»‘è´¨Sirt3/NLRP3/GSDMD信号通路的影响.

OBJECTIVES: To observe the effects on tyrosine hydroxylase (TH), α-synaptic nucleoprotein (α-syn), sirtuin 3 (Sirt3), NOD-like receptor 3 (NLRP3) and gasdermin-D (GSDMD) in the substantia nigra of midbrain after electroacupuncture (EA) at "Fengfu"(GV16), "Taichong" (LR3) and "Zusanli" (ST36) in rats of Parkinson's disease (PD), so as to explore the mechanism of EA in treatment of PD. METHODS: SD rats were randomly divided into control, model and EA groups, with 10 rats in each group. The PD model was established by injecting rotenone into the neck and back, lasting 28 days. In the EA group, EA was applied to GV16, LR3 and ST36, 30 min each time, once daily, consecutively for 28 days. The open-field test was adopted to detect the total distance of autonomic movement of rats, and the pole climbing test was used to detect the body coordination ability of rats. In the substania nigra of midbrain, the positive expression of TH was determined using immunohistochemistry, the mRNA expression levels of α - syn, Sirt3, NLRP3 and GSDMD were detected by quantitative real-time fluorescence PCR, and the protein expression levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and cysteinyl aspartate specific proteinase (Caspase)-1 were detected by Western blot. RESULTS: Compared with the control group, the total distance of autonomous movement was decreased (P<0.01) in the model group, and the score of pole climbing experiment was increased (P<0.01)；in the midbrain substantia nigra the positive expression of TH was decreased (P<0.01)；the mRNA expression level of Sirt3 was decreased (P<0.01), and those of α-syn, NLRP3 and GSDMD were increased (P<0.01)；while the protein expression levels of NLRP3, ASC and Caspase-1 were increased (P<0.01). When compared with the model group, the total distance of autonomous movement in open field experiment was increased (P<0.01) in the EA group and the score of pole climbing experiment was lower (P<0.05)；in the midbrain substantia nigra the positive expression of TH was increased (P<0.01)；the mRNA expression level of Sirt3 in the midbrain substantia nigra was increased (P<0.01), and those of α-syn, NLRP3 and GSDMD were reduced (P<0.01)；while the protein expression levels of NLRP3, ASC and Caspase-1 decreased (P<0.01, P<0.05). CONCLUSIONS: EA at "GV16" "LR3" and "ST36" can repair the neuronal injury, clear the abnormal accumulation of α-syn in the substania nigra of midbrain, and ameliorate mitochondrial damage in PD rats, which may be obtained by regulating Sirt3/NLRP3/GSDMD signaling pathway, so as to delay the occurrence and development of Parkinson's disease.

Macrod1 suppresses diabetic cardiomyopathy via regulating PARP1-NAD+-SIRT3 pathway.

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with oxidative stress, inflammation and apoptosis in the heart. MACRO domain containing 1 (Macrod1) is an ADP-ribosylhydrolase 1 that is highly enriched in mitochondria, participating in the pathogenesis of cardiovascular diseases. In this study, we investigated the role of Macrod1 in DCM. A mice model was established by feeding a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). We showed that Macrod1 expression levels were significantly downregulated in cardiac tissue of DCM mice. Reduced expression of Macrod1 was also observed in neonatal rat cardiomyocytes (NRCMs) treated with palmitic acid (PA, 400 µM) in vitro. Knockout of Macrod1 in DCM mice not only worsened glycemic control, but also aggravated cardiac remodeling, mitochondrial dysfunction, NAD+ consumption and oxidative stress, whereas cardiac-specific overexpression of Macrod1 partially reversed these pathological processes. In PA-treated NRCMs, overexpression of Macrod1 significantly inhibited PARP1 expression and restored NAD+ levels, activating SIRT3 to resist oxidative stress. Supplementation with the NAD+ precursor Niacin (50 µM) alleviated oxidative stress in PA-stimulated cardiomyocytes. We revealed that Macrod1 reduced NAD+ consumption by inhibiting PARP1 expression, thereby activating SIRT3 and anti-oxidative stress signaling. This study identifies Macrod1 as a novel target for DCM treatment. Targeting the PARP1-NAD+-SIRT3 axis may open a novel avenue to development of new intervention strategies in DCM. Schematic illustration of macrod1 ameliorating diabetic cardiomyopathy oxidative stress via PARP1-NAD+-SIRT3 axis.

Effects of electroacupuncture on mitophagy mediated by SIRT3/PINK1/Parkin pathway in Parkinson's disease mice. / ç”µé’ˆå¯¹å¸•é‡‘æ£®ç— å°é¼ SIRT3/PINK1/Parkin通路介导的线粒体自噬的影响.

OBJECTIVES: To observe the effects of electroacupuncture (EA) at "Fengfu"(GV16), "Taichong"(LR3), and "Zusanli"(ST36) on mitophagy mediated by silencing regulatory protein 3 (SIRT3)/ PTEN induced putative kinase 1 (PINK1)/PARK2 gene coding protein (Parkin) in the midbrain substantia nigra of Parkinson's disease (PD) mice, and to explore the potential mechanisms of EA in treating PD. METHODS: C57BL/6 mice were randomly divided into the control, model, EA, and sham EA groups, with 12 mice in each group. The PD mouse model was established by intraperitoneal injection of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). The EA group received EA stimulation at GV16, LR3 and ST36, while the sham EA group received shallow needling 1 mm away from the above acupoints without electrical stimulation. The motor ability of mice in each group was evaluated using an open field experiment. Immunohistochemistry was used to detect the expression of tyrosine hydroxylase (TH) and α-synuclein (α-syn) in the substantia nigra of mice. The ultrastructure of neurons in substantia nigra was observed by transmission electron microscope (TEM). Immunofluorescence was used to detect the expression of the autophagy marker autophagy-associated protein light chain 3 (LC3). The expression levels of TH, α-syn, SIRT3, PINK1, Parkin, P62, Beclin-1, LC3Ⅱ mRNA and protein were detected by PCR and Western blot. RESULTS: Compared with the control group, mice in the model group showed a decrease in the total exercise distance, time, movement speed and times of crossing central region (P<0.01)；the positive expressions of TH and LC3 were decreased (P<0.01), while the positive expression of α-syn increased (P<0.01), accompanied by mitochondrial swelling, mitochondrial cristae fragmentation and decrease, and decreased lysosome count；the expression levels of TH, SIRT3, PINK1, Parkin, Beclin-1, and LC3Ⅱ mRNA and protein in the midbrain substantia nigra were decreased (P<0.01), while the expression levels of α-syn and P62 mRNA and protein were increased (P<0.01, P<0.05). Compared with the model group, the mice in EA group showed a significant increase in the total exercise distance, time, movement speed and times of crossing central region (P<0.01, P<0.05)；the positive expressions of TH and LC3 were increased (P<0.01, P<0.05), while the positive expression of α-syn was decreased (P<0.01), accompanied by an increase in mitochondrial count, appearance of autophagic va-cuoles, and a decrease in swelling, the expression levels of TH, SIRT3, PINK1, Parkin, Beclin-1 and LC3Ⅱ mRNA and protein in the midbrain substantia nigra were increased (P<0.01, P<0.05), while the mRNA and protein expression levels of α-syn and P62 were decreased (P<0.01)；the sham EA group showed an increase in the total exercise distance and time(P<0.05), with an increase in the positive expression of TH (P<0.05) and a decrease in the positive expression of α-syn (P<0.05)；some mitochondria exhibited swelling, and no autophagic vacuoles were observed；the protein expression levels of TH, SIRT3, Parkin and LC3Ⅱ were increased (P<0.01, P<0.05), and the expression levels of P62 mRNA, α-syn mRNA and protein were decreased (P<0.01, P<0.05), and LC3Ⅱ mRNA expression was increased (P<0.05). In comparison to the sham EA group, the EA group showed an extension in the total exercise time (P<0.01), the positive expression and mRNA expression levels of α-syn were decreased (P<0.01, P<0.05), while the expression levels of TH, SIRT3, PINK1, Parkin mRNA and SIRT3 protein were increased (P<0.05). CONCLUSIONS: EA at GV16, LR3, and ST36 can exert neuroprotective function and improve the motor ability of PD mice by activating the SIRT3/PINK1/Parkin pathway to enhance the expression of TH and reduce α-syn aggregation in the substantia nigra of PD mice.

Indole-3-Propionic Acid Protects Against Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a common but poorly understood form of heart failure, characterized by impaired diastolic function. It is highly heterogeneous with multiple comorbidities, including obesity and diabetes, making human studies difficult. METHODS: Metabolomic analyses in a mouse model of HFpEF showed that levels of indole-3-propionic acid (IPA), a metabolite produced by gut bacteria from tryptophan, were reduced in the plasma and heart tissue of HFpEF mice as compared with controls. We then examined the role of IPA in mouse models of HFpEF as well as 2 human HFpEF cohorts. RESULTS: The protective role and therapeutic effects of IPA were confirmed in mouse models of HFpEF using IPA dietary supplementation. IPA attenuated diastolic dysfunction, metabolic remodeling, oxidative stress, inflammation, gut microbiota dysbiosis, and intestinal epithelial barrier damage. In the heart, IPA suppressed the expression of NNMT (nicotinamide N-methyl transferase), restored nicotinamide, NAD+/NADH, and SIRT3 (sirtuin 3) levels. IPA mediates the protective effects on diastolic dysfunction, at least in part, by promoting the expression of SIRT3. SIRT3 regulation was mediated by IPA binding to the aryl hydrocarbon receptor, as Sirt3 knockdown diminished the effects of IPA on diastolic dysfunction in vivo. The role of the nicotinamide adenine dinucleotide circuit in HFpEF was further confirmed by nicotinamide supplementation, Nnmt knockdown, and Nnmt overexpression in vivo. IPA levels were significantly reduced in patients with HFpEF in 2 independent human cohorts, consistent with a protective function in humans, as well as mice. CONCLUSIONS: Our findings reveal that IPA protects against diastolic dysfunction in HFpEF by enhancing the nicotinamide adenine dinucleotide salvage pathway, suggesting the possibility of therapeutic management by either altering the gut microbiome composition or supplementing the diet with IPA.

Electroacupuncture Mediates Fat Metabolism and Autophagy via a Sirt3-Dependent Mechanism in Mice Fed High-Fat Diet.

This study investigates the therapeutic potential of electroacupuncture (EA) on obesity, focusing on its influence on autophagy and energy metabolism, utilizing a high-fat diet (HFD)-induced mouse model. Treatment with EA significantly reduces body weight, fat deposition, and lipid accumulation in HFD-fed mice. Additionally, EA effectively ameliorates metabolic imbalances, reducing blood glucose levels and plasma markers of liver function. At the molecular level, EA enhances the expression of thermogenesis-associated genes in brown adipose tissue and decreases p53 expression, suggesting a decrease in apoptosis. Autophagy in white adipose tissue is inhibited by EA, as demonstrated by the suppression of key autophagy-related proteins. Further experiments highlight the critical role of Sirtuin 3 (Sirt3) in EA's anti-obesity effects. Sirt3 supplementation combined with EA results in reduced body weight, fat deposition, and lipid accumulation, along with modulations in key metabolic indicators. Moreover, EA's modulatory effect on uncoupling protein 1 (Ucp1), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α), and p53 is found to be Sirt3 dependent. In conclusion, EA exerts beneficial effects against obesity through Sirt3-dependent modulation of autophagy and energy metabolism, indicating a potential therapeutic approach for obesity and related metabolic disorders.

Fufang Zhenzhu Tiaozhi (FTZ) capsule ameliorates diabetes-accelerated atherosclerosis via suppressing YTHDF2-mediated m6A modification of SIRT3 mRNA.

ETHNOPHARMACOLOGICAL RELEVANCE: Fufang Zhenzhu TiaoZhi (FTZ), a Chinese medicinal decoction, has continuously been used to treat metabolic syndrome. Atherosclerosis is the main pathological basis of cardiovascular disease. The N6 methyladenosine (m6A) modification is a highly dynamic and reversible process involving a variety of important biological processes. AIM OF THE STUDY: Here, we investigated the therapeutic effects and mechanism of FTZ in diabetes-accelerated atherosclerosis. MATERIALS AND METHODS: Doppler ultrasonography was used to examine the carotid intima-media thickness and plaque area in diabetic atherosclerosis patients. HFD mice were injected with streptozotocin to induce diabetes. HE and Oil red O staining were used to assess the effect of FTZ on lipid deposition. HUVECs were induced with HG/ox-LDL as a model of diabetic atherosclerosis. Furthermore, application of m6A methylation level kit, qRT-PCR, Western blot, tunel staining, reactive oxygen species staining and mPTP staining were performed to analyze the detailed mechanism. RESULTS: Clinical trials of FTZ have shown obvious effect of lowering blood glucose and blood lipids. These effects were reversed after FTZ intervention. Compared with the control, lipid deposition decreased significantly after FTZ administration. FTZ reduced endothelial cell apoptosis. At the same time, we found that FTZ reversed the increase of methylation reader YTHDF2 caused by ox-LDL treatment. Subsequently, we discovered that YTHDF2 degraded SIRT3 mRNA, leading to endothelial cell apoptosis and oxidative stress. CONCLUSION: FTZ attenuated diabetes-accelerated atherosclerosis by decreasing blood glucose and serum lipids levels, and increased endothelial cell antioxidant capacity, inhibited endothelial cell apoptosis via inhibiting YTHDF2-mediated m6A modification of SIRT3 mRNA, which reduced mRNA degradation.

Duhuo Jisheng Decoction suppresses apoptosis and mitochondrial dysfunction in human nucleus pulposus cells by miR-494/SIRT3/mitophagy signal axis.

BACKGROUND: Increasing evidence suggests that mitophagy is responsible for the pathogenesis of intervertebral disk (IVD) degeneration. Previous studies have shown that Duhuo Jisheng Decoction (DHJSD), a classic Fangji of traditional Chinese medicine, can delay IVD degeneration; however, its specific mechanism of action is unknown. In this study, we investigated the mechanism by which DHJSD treatment prevented IVD degeneration in IL-1ß-treated human nucleus pulposus (NP) cells in vitro. METHODS: Cell Counting Kit-8 was performed to explore the effects of DHJSD on the viability of NP cells exposed to IL-1ß. The mechanism by which DHJSD delays IVD degeneration was explored using luciferase reporter assay, RT-qPCR, western blotting, TUNEL assay, mitophagy detection assay, Mito-SOX, Mitotracker and in situ hybridization. RESULTS: We observed that DHJSD enhanced the viability of NP cells treated with IL-1ß in a concentration-time dependent approach. Moreover, DHJSD lessened IL-1ß-induced NP apoptosis and mitochondrial dysfunction and activated mitophagy in NP cells treated with IL-1ß. Mitophagy suppressor cyclosporin A reversed the beneficial impacts of DHJSD in NP cells. In addition, the differential expression of miR-494 regulated IL-1ß-induced NP apoptosis and mitochondrial dysfunction, and the protective impact of miR-494 on NP cells treated with IL-1ß was achieved by mitophagy activation, which was regulated by its target gene, sirtuin 3 (SIRT3). Finally, we observed that DHJSD treatment could effectively delay IL-1ß-induced NP apoptosis by affecting the miR-494/SIRT3/mitophagy signal axis. CONCLUSIONS: These results show that the miR-494/SIRT3/mitophagy signaling pathway is responsible for the apoptosis and mitochondrial dysfunction of NP cells and that DHJSD may exert protective effects against IVD degeneration by regulating the miR-494/SIRT3/mitophagy signal axis.

Spinal Sirtuin 3 Contributes to Electroacupuncture Analgesia in Mice With Chronic Constriction Injury-Induced Neuropathic Pain.

BACKGROUND: Electroacupuncture (EA) is a traditional Chinese therapeutic technique that has a beneficial effect on neuropathic pain; however, the specific mechanism remains unclear. In this study, we investigated whether EA inhibits spinal Ca/calmodulin-dependent protein kinase II (CaMKIIα) phosphorylation through Sirtuin 3 (SIRT3) protein, thus relieving neuropathic pain. MATERIALS AND METHODS: We used wild-type and SIRT3 knockout (SIRT3-/-) mice and used chronic constriction injury (CCI) as a pain model. We performed Western blotting, immunostaining, von Frey, and Hargreaves tests to gather biochemical and behavioral data. Downregulation and overexpression and spinal SIRT3 protein were achieved by intraspinal injection of SIRT3 small interfering RNA and intraspinal injection of lentivirus-SIRT3. To test the hypothesis that CaMKIIα signaling was involved in the analgesic effects of EA, we expressed CaMKIIα-specific designer receptors exclusively activated by designer drugs (DREADDs) in the spinal dorsal horn (SDH) of mice. RESULTS: These results showed that the mechanical and thermal hyperalgesia induced by CCI was related to the decreased spinal SIRT3 expression in the SDH of mice. A significant reduction of mechanical and thermal thresholds was found in the SIRT3-/- mice. SIRT3 overexpression or EA treatment alleviated CCI-induced neuropathic pain and prevented the spinal CaMKIIα phosphorylation. Most importantly, EA increased the expression of spinal SIRT3 protein in the SDH. Downregulation of spinal SIRT3 or CaMKIIα Gq-DREADD activation inhibited the regulatory effect of EA on neuropathic pain. CONCLUSION: Our results showed that CaMKIIα phosphorylation was inhibited by spinal SIRT3 in neuropathic pain and that EA attenuated CCI-induced neuropathic pain mainly by upregulating spinal SIRT3 expression in the SDH of mice.

[Electroacupuncture preconditioning alleviates renal injury and oxidative stress through Sirt3/MnSOD pathway in type 2 diabetic rats].

OBJECTIVE: To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury in type 2 diabetic rats. METHODS: Fifty male Wistar rats were randomly divided into control, model, EA, EA+inhibitor, and inhibitor groups, with 10 rats in each group. Diabetes model was established by high fat and high glucose diet and intraperitoneal injection of streptozotocin (40 mg/kg). EA (2 Hz, 1 mA) preconditioning was applied to "Guanyuan" (CV4), "Zhongwan" (CV12), bilateral "Zusanli" (ST36) and "Fenglong" (ST40) for 15 min, once every other day for 8 weeks. Rats of the inhibitor and EA+inhibitor groups were given intraperitoneal injection of 3-TYP (50 mg/kg) once every other day for a total of 3 times. The body weight, kidney mass, and renal index were recorded. The contents of urine microalbumin (ALB), 24 h urine 8-hydroxydeoxyguanosine (8-OHdG) and activities of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione glycine peroxidase (GSH-Px) in kidney were detected by ELISA. The activities of mitochondrial respiratory chain enzyme complex (RCCⅠ-RCCⅣ) in kidney were detected using spectrophotometric method. HE staining, Masson staining and transmission electron microscopy were used to observe the changes of renal structure. The protein and mRNA expressions of silent information regulator 3 (Sirt3), manganese superoxide dismutase (MnSOD) in kidney were detected by Western blot and quantitative real-time PCR, respectively. RESULTS: After modeling and compared with the control group, the contents of ALB, the renal index, activity of ROS and content of 8-OHdG, and the renal collagen volume fraction (CVF) were increased (P<0.01), while the activities of SOD, CAT and GSH-Px, RCCⅠ-RCCⅣ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.01). After the treatment and compared with the model group, the contents of ALB, the renal index, ROS, 8-OHdG, and the CVF were decreased in the EA group(P<0.01, P<0.05), while the activities of SOD, CAT, GSH-Px, RCCⅠ-RCCⅣ, and Sirt3 and MnSOD expression levels were increased (P<0.01, P<0.05)；the RCCⅡ activity and the expression level of MnSOD mRNA were increased (P<0.05) in the EA+inhibitor group; the ALB and 8-OHdG contents and the CVF in the inhibitor group were increased (P<0.05), while the activity of SOD, and Sirt3 and MnSOD expression levels were decreased (P<0.05). In comparison with the EA group, the contents of ALB, the renal index, activities of ROS and 8-OHdG contents, and the CVF were increased (P<0.05, P<0.01), activities of SOD, CAT and GSH-Px and RCCⅠ and RCCⅡ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.05, P<0.01) in both EA+inhibitor group and inhibitor group, whereas the activities of RCCⅢ and RCCⅣ were decreased in the inhibitor group (P<0.05). The therapeutic effect of inhibitor was notably inferior to that of EA+inhibitor in decreasing ALB and 8-OHdG contents, and CVF (P<0.01), and in up-regulating SOD and RCCⅡ activities, Sirt3 and MnSOD expression levels (P<0.01, P<0.05). CONCLUSION: EA preconditioning can increase the expressions of renal Sirt3 and MnSOD in type 2 diabetic rats, thereby reducing the oxidative stress response and protecting the kidneys.

Wenshen Yangxue decoction promotes follicular development in aged female mice stimulation of the silent information regulator 3/forkhead transcription factor O1 3a pathway.

OBJECTIVE: To primarily explore the effect and mechanism of Wenshen Yangxue decoction in promoting follicular development in elderly female mice. METHODS: Fifty Institute of Cancer Research mice were randomly divided into blank, controlled ovarian hyperstimulation (COH), low-dose Wenshen Yangxue decoction, medium-dose Wenshen Yangxue decoction, and high-dose Wenshen Yangxue decoction groups, with 10 mice in each group. The number of ovulations, number of fertilizations, mitochondrial adenosine triphosphate (ATP) level, and mitochondrial DNA (mtDNA) of oocytes in each group were compared. Reverse transcription-polymerase chain reaction and Western blotting were used to detect the mRNA and protein expression levels of silent information regulator 3 (Sirt3) and forkhead transcription factor O1 3a (FOXO3a). RESULTS: Wenshen Yangxue decoction significantly increased the number of ovulations in mice (P < 0.05) and promoted the formation of fertilized eggs. The ATP level and mtDNA copy number of mice oocytes in the high-dose groups were significantly higher than those in the COH group (P < 0.05). Wenshen Yangxue decoction significantly increased the mRNA and protein levels of Sirt3 and FOXO3a in mouse oocytes. CONCLUSION: Wenshen Yangxue decoction promoted the development of follicles in elderly female mice, increased the number of ovulations and improved fertility. Its mechanism may be related to increased mitochondrial energy metabolism and regulation of the Sirt3/FOXO3a pathway.

Icariin attenuates excessive alcohol consumption-induced susceptibility to atrial fibrillation through SIRT3 signaling.

Excessive alcohol consumption has long been identified as a risk factor for adverse atrial remodeling and atrial fibrillation (AF). Icariin is a principal active component from traditional Chinese medicine Herba Epimedii and has been demonstrated to exert potential antiarrhythmic effect. The present study was designed to evaluate the effect of icariin against alcohol-induced atrial remodeling and disruption of mitochondrial dynamics and furthermore, to elucidate the underlying mechanisms. Excessive alcohol-treated C57BL/6 J mice were infected with serotype 9 adeno-associated virus (AAV9) carrying mouse SIRT3 gene or negative control virus. Meanwhile, icariin (50 mg/kg/d) was administered to the animals in the presence or absence of AAV9 carrying SIRT3 shRNA. We noted that 8 weeks of icariin treatment effectively attenuated alcohol consumption-induced atrial structural and electrical remodeling as evidenced by reduced AF inducibility and reversed atrial electrical conduction pattern as well as atrial enlargement. Furthermore, icariin-treated group exhibited significantly enhanced atrial SIRT3-AMPK signaling, decreased atrial mitoSOX fluorescence and mitochondrial fission markers, elevated mitochondrial fusion markers (MFN1, MFN2) as well as NRF-1-Tfam-mediated mitochondrial biogenesis. Importantly, these beneficial effects were mimicked by SIRT3 overexpression while abolished by SIRT3 knockdown. These data revealed that targeting atrial SIRT3-AMPK signaling and preserving mitochondrial dynamics might serve as the novel therapeutic strategy against alcohol-induced AF genesis. Additionally, icariin ameliorated atrial remodeling and mitochondrial dysfunction by activating SIRT3-AMPK signaling, highlighting the use of icariin as a promising antiarrhythmic agent in this circumstance.

Protective Effect of Cordycepin on Impairment of Endothelial Function in Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a major risk factor for cardiovascular diseases. The reduction of mitochondrial protein sirtuin protein 3 (SIRT3) has been reported to contribute to the development of T2DM by impacting mitochondrial respiration. Cordycepin is an adenosine derivative and is isolated from the culture filtrate of Cordyceps militaris. This study explored the protective effect of cordycepin on vascular impairment induced by T2DM and its properties and protective mechanism. In this study, a T2DM rat model was established. The endothelium-dependent relaxation of the thoracic aorta ring decreased in T2DM rats could be reversed by cordycepin. Next, mitochondrial impairment in human umbilical vein endothelial cells was detected by JC-1 staining. In vitro studies revealed that cordycepin plays a beneficial role in advanced glycation end product-induced endothelial mitochondrial impairment. Moreover, according to the cordycepin molecular docking analysis, cordycepin can bind to SIRT3. Cordycepin increased the expression and activation of SIRT3 in a dose-dependent manner. SIRT3 interruption blocked the protective effect of cordycepin on mitochondria in human umbilical vein endothelial cells. Cordycepin can conclusively protect vascular function impaired by T2DM, and the mechanism may potentially be involved in SIRT3 signaling pathways.

FTZ protects against cardiac hypertrophy and oxidative injury via microRNA-214 / SIRT3 signaling pathway.

BACKGROUND: Despite the fact that the initial hypertrophic response to ventricular pressure overload is thought to be compensatory, prolonged stress often leads to heart failure. Previous studies have shown that the Fufang-Zhenzhu-Tiaozhi (FTZ) formula is beneficial for the treatment of dyslipidemia and hyperglycemia. However, the effects of FTZ on cardiac hypertrophy remain unclear. OBJECTIVE: The aim of this study is to evaluate the protective effects of FTZ on cardiac hypertrophy and determine the underlying mechanisms. METHODS: TAC was utilized to establish a cardiac hypertrophy animal model, and FTZ was given via gavage for four weeks. Next, echocardiographic measurements were made. The morphology of mouse cardiomyocytes was examined using H&E and WGA staining. In vitro, the neonatal cardiomyocytes were stimulated with angiotensin Ⅱ (Ang Ⅱ). In addition to measuring the size of cardiomyocytes, qRT-PCR and western blotting were conducted to measure cardiac stress markers and pathway. RESULTS: According to our findings, FTZ alleviated cardiac hypertrophy in mice and cell models. Furthermore, expression of miR-214 was down-regulated following FTZ, whereas the effect of FTZ therapy was reversed using miR-214 transfection. Furthermore, the expression of Sirtuin 3 (SIRT3) was decreased in Ang Ⅱ-induced oxidative damage, which was associated with a reduction in SOD-1, GPX1, and HO-1 and an increase in MDA, while SIRT3 expression was restored following FTZ treatment. CONCLUSIONS: Collectively, these findings indicate that FTZ is a protective factor for cardiac hypertrophy due to its regulation of the miR-214-SIRT3 axis, which suggests that FTZ may be a therapeutic target for cardiac hypertrophy.

Tubeimoside I Ameliorates Myocardial Ischemia-Reperfusion Injury through SIRT3-Dependent Regulation of Oxidative Stress and Apoptosis.

Myocardial ischemia-reperfusion injury (MIRI) is a phenomenon that reperfusion leads to irreversible damage to the myocardium and increases mortality in acute myocardial infarction (AMI) patients. There is no effective drug to treat MIRI. Tubeimoside I (TBM) is a triterpenoid saponin purified from Chinese traditional medicine tubeimu. In this study, 4 mg/kg TBM was given to mice intraperitoneally at 15 min after ischemia. And TBM treatment improved postischemic cardiac function, decreased infarct size, diminished lactate dehydrogenase release, ameliorated oxidative stress, and reduced apoptotic index. Notably, ischemia-reperfusion induced a significant decrease in cardiac SIRT3 expression and activity, while TBM treatment upregulated SIRT3's expression and activity. However, the cardioprotective effects of TBM were largely abolished by a SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). This suggests that SIRT3 plays an essential role in TBM's cardioprotective effects. In vitro, TBM also protected H9c2 cells against simulated ischemia/reperfusion (SIR) injury by attenuating oxidative stress and apoptosis, and siSIRT3 diminished its protective effects. Taken together, our results demonstrate for the first time that TBM protects against MIRI through SIRT3-dependent regulation of oxidative stress and apoptosis. TBM might be a potential drug candidate for MIRI treatment.

Dietary Cocoa Flavanols Enhance Mitochondrial Function in Skeletal Muscle and Modify Whole-Body Metabolism in Healthy Mice.

Mitochondrial dysfunction is widely reported in various diseases and contributes to their pathogenesis. We assessed the effect of cocoa flavanols supplementation on mitochondrial function and whole metabolism, and we explored whether the mitochondrial deacetylase sirtuin-3 (Sirt3) is involved or not. We explored the effects of 15 days of CF supplementation in wild type and Sirt3-/- mice. Whole-body metabolism was assessed by indirect calorimetry, and an oral glucose tolerance test was performed to assess glucose metabolism. Mitochondrial respiratory function was assessed in permeabilised fibres and the pyridine nucleotides content (NAD+ and NADH) were quantified. In the wild type, CF supplementation significantly modified whole-body metabolism by promoting carbohydrate use and improved glucose tolerance. CF supplementation induced a significant increase of mitochondrial mass, while significant qualitative adaptation occurred to maintain H2O2 production and cellular oxidative stress. CF supplementation induced a significant increase in NAD+ and NADH content. All the effects mentioned above were blunted in Sirt3-/- mice. Collectively, CF supplementation boosted the NAD metabolism that stimulates sirtuins metabolism and improved mitochondrial function, which likely contributed to the observed whole-body metabolism adaptation, with a greater ability to use carbohydrates, at least partially through Sirt3.

Effect of extracts and isolated compounds derived from Retama monosperma (L.) Boiss. on anti-aging gene expression in human keratinocytes and antioxidant activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Moroccan folk medicine treats skin cicatrization with Retama monosperma (L.) Boiss. locally named "Rtem", but the mechanism involved is still not well known. Traditional healers use the plant in small doses as an anthelmintic, disinfectant and an effective abortive. In addition, the cladodes powder mixed with honey is employed as purgative and vermifuge. Equally, the SIRT1 and SIRT3 genes activation and sirtuin proteins expression, which delay cellular senescence, participate in wound healing and skin regeneration especially, SIRT1 the most studied gene, leads to fast skin restoration and cicatrization. AIM OF THE STUDY: In this study, we evaluated the ability of the Retama monosperma (L.)Boiss. flowers and seeds extracts and the isolated compounds in augmenting the SIRT1 and SIRT3 gene expression in HaCaT cells and expressing the antioxidant activity. MATERIALS AND METHODS: We examined for quantitative expression levels of SIRT1 and SIRT3 in HaCaT cell by qRT-PCR and the antioxidant activity by four tests (conjugated diene, TBARS assay, DPPH scavenging activity and H2O2 radical scavenging assay) of diethyl ether extract of flowers (DEF extract) and ethyl acetate extract of seeds (EAS extract) of R. monosperma(L.) Boiss. and the isolated compounds (quercetin, 6-methoxykaempferol, kaempferol and genistein). RESULTS: The screening system by EGFP fluorescence revealed that all samples and resveratrol significantly increase SIRT1 and SIRT3 promoters activities in HaCaT cells with p< 0.05. Furthermore, EAS, quercetin, 6-methoxykaempferol and kaempferol increase significantly (p< 0.05) SIRT1 (3.43, 1.18, 2.62, and 1.72 expression quantity, respectively) and SIRT3 (16.27, 5.01, 3.01, and 6.18 expression quantity, respectively) in HaCaT cells. On the other hand, genistein has a moderate activity on SIRT1 and SIRT3 with 1.43 and 2.04 expression levels. For the antioxidant activity, the EAS and the pure compounds exhibited stronger antioxidant activity than BHT. While DEF and genistein have a moderate antioxidant activity when compared with BHT. CONCLUSIONS: In this study, the expression levels of SIRT1 and SIRT3 in HaCaT cells increase in the presence of extracts of R. monosperma (L.) Boiss. and the pure compounds.

Lycopene attenuates di(2-ethylhexyl) phthalate-induced mitophagy in spleen by regulating the sirtuin3-mediated pathway.

Lycopene (Lyc) has been discussed as a potential effector in the prevention and therapy of various diseases. Di(2-ethylhexyl) phthalate (DEHP) is regarded as a universal environmental pollutant. To clarify the potential protective effect of Lyc on DEHP-induced splenic injury, 140 male mice were randomized into seven groups: control (distilled water), vehicle control (corn oil per day), Lyc (5 mg per kg BW per day), DEHP (500 or 1000 mg per kg BW per day), and DEHP combined Lyc group, respectively. All experimental animals were treated by oral gavage for 28 days. The results that showed DEHP exposure significantly up-regulated the mRNA and protein expression of the sirtuin family (except SIRT4-5), PGC-1α, OPA1, Drp1, MFN1/2, NRF1, TFAM, Parkin and PINK in DEHP-treated alone groups and the SOD2 and LC3-II protein expression were also in accordance with the above changes. These were accompanied with an increase of the number of inflammatory cells and rate of mitochondrial damage, and autophagosome formation in the spleen. Notably, Lyc supplementation facilitated all these changes to effectively return to the normal level, indicating that Lyc exerts protective effects against DEHP-induced splenic toxicity. Altogether, the protective effects of Lyc may be a strategy to ameliorate DEHP-induced spleen damage.

SIRT3 is required for liver regeneration but not for the beneficial effect of nicotinamide riboside.

Liver regeneration is critical to survival after traumatic injuries, exposure to hepatotoxins, or surgical interventions, yet the underlying signaling and metabolic pathways remain unclear. In this study, we show that hepatocyte-specific loss of the mitochondrial deacetylase SIRT3 drastically impairs regeneration and worsens mitochondrial function after partial hepatectomy. Sirtuins, including SIRT3, require NAD as a cosubstrate. We previously showed that the NAD precursor nicotinamide riboside (NR) promotes liver regeneration, but whether this involves sirtuins has not been tested. Here, we show that despite their NAD dependence and critical roles in regeneration, neither SIRT3 nor its nuclear counterpart SIRT1 is required for NR to enhance liver regeneration. NR improves mitochondrial respiration in regenerating WT or mutant livers and rapidly increases oxygen consumption and glucose output in cultured hepatocytes. Our data support a direct enhancement of mitochondrial redox metabolism as the mechanism mediating improved liver regeneration after NAD supplementation and exclude signaling via SIRT1 and SIRT3. Therefore, we provide the first evidence to our knowledge for an essential role for a mitochondrial sirtuin during liver regeneration and insight into the beneficial effects of NR.

Melatonin sensitises shikonin-induced cancer cell death mediated by oxidative stress via inhibition of the SIRT3/SOD2-AKT pathway.

Recent research suggests that melatonin (Mel), an endogenous hormone and natural supplement, possesses anti-proliferative effects and can sensitise cells to anti-cancer therapies. Although shikonin (SHK) also possesses potential anti-cancer properties, the poor solubility and severe systemic toxicity of this compound hinders its clinical usage. In this study, we combined Mel and SHK, a potentially promising chemotherapeutic drug combination, with the aim of reducing the toxicity of SHK and enhancing the overall anti-cancer effects. We demonstrate for the first time that Mel potentiates the cytotoxic effects of SHK on cancer cells by inducing oxidative stress via inhibition of the SIRT3/SOD2-AKT pathway. Particularly, Mel-SHK treatment induced oxidative stress, increased mitochondrial calcium accumulation and reduced the mitochondrial membrane potential in various cancer cells, leading to apoptosis. This drug combination also promoted endoplasmic reticulum (ER) stress, leading to AKT dephosphorylation. In HeLa cells, Mel-SHK treatment reduced SIRT3/SOD2 expression and SOD2 activity, while SIRT3 overexpression dramatically reduced Mel-SHK-induced oxidative stress, ER stress, mitochondrial dysfunction and apoptosis. Hence, we propose the combination of Mel and SHK as a novel candidate chemotherapeutic regimen that targets the SIRT3/SOD2-AKT pathway in cancer.

ROS Mediate xCT-Dependent Cell Death in Human Breast Cancer Cells under Glucose Deprivation.

xCT, also known as solute carrier family 7 member 11 (SLC7A11), the light chain of the cystine/glutamate antiporter, is positively correlated with cancer progression due to antioxidant function. During glucose deprivation, the overexpression of xCT does not protect cancer cells but instead promotes cell death. Further understanding the mechanism of glucose deprivation-induced cell death is important for developing anticancer treatments targeting the glucose metabolism. In this study, we found that breast cancer cells with a high expression of xCT demonstrated increased levels of reactive oxygen species (ROS) and were more sensitive to glucose deprivation than the cells with a low expression of xCT. However, AMP-activated protein kinase (AMPK) did not significantly affect glucose-deprivation-induced cell death. The antioxidant N-acetyl-cysteine prevented glucose-deprivation-induced cell death, and the glutathione biosynthesis inhibitor L-buthionine-S, R-sulfoximine enhanced glucose-deprivation-induced cell death. The inhibition of xCT by sulfasalazine or a knockdown of xCT reduced the glucose-deprivation-increased ROS levels and glucose-deprivation-induced cell death. Glucose deprivation reduced the intracellular glutamate, and supplementation with α-ketoglutarate prevented the glucose-deprivation-increased ROS levels and rescued cell death. The knockdown of sirtuin-3 (SIRT3) further enhanced the ROS levels, and promoted xCT-related cell death after glucose deprivation. In conclusion, our results suggested that ROS play a critical role in xCT-dependent cell death in breast cancer cells under glucose deprivation.