SIRT3 inhibited the formation of calcium oxalate-induced kidney stones through regulating NRF2/HO-1 signaling pathway

Oxidative stress is important for the calcium oxalate (CaOx)-induced kidney stone formation. Sirtuin 3 (SIRT3) plays an essential role in the amelioration of oxidative damages. This study aims to explore the effect of SIRT3 on the formation of CaOx-induced kidney stones and the underlying mechanism. SIRT3 expression in renal tissues was detected by immunohistochemistry. Apoptosis in renal tissues was examined by TUNEL staining. Crystal-cell adherence and cell apoptosis in HK-2 cells were assessed by analyzing Ca²⁺ concentration and by the flow cytometry analysis, respectively. Protein expression of SIRT3, nuclear factor erythroid 2-related factor (NRF2), heme oxygenase-1 (HO-1), and Bax in renal tissues or HK-2 cells was examined by Western blot analysis. Renal pathological changes and the adhesion of CaOx crystals in the kidneys were examined by hematoxylin-eosin and von Kossa staining, respectively. Human kidneys with stones showed enhanced renal apoptosis, downregulated SIRT3 expression, and upregulated NRF2/HO-1 expression, compared with the controls. Furthermore, SIRT3 overexpression inhibited the CaOx-induced promotion of crystal-cell adherence and cell apoptosis in human proximal tubular cell line HK-2 cells, which was reversed by the NRF2 knockdown. Moreover, our in vivo assay further confirmed that SIRT3 overexpression alleviated the glyoxylate administration-induced renal damage, renal apoptosis, and crystals deposition in the kidneys from the stone model mice, which was also associated with its activation of the NRF2/HO-1 pathway. Our findings support the notion that overexpression of SIRT3 may inhibit the formation of CaOx-induced kidney stones, at least in part, through regulating the NRF2/HO-1 signaling pathway.     

Ferroptosis in calcium oxalate kidney stone formation and the possible regulatory mechanism of ANKRD1

The objective of this study was to explore the role of ferroptosis in the formation of calcium oxalate (CaOx) kidney stones and the regulatory mechanism of the ankyrin repeat domain 1 (ANKRD1) gene. The study found that the Nrf2/HO-1 and p53/SLC7A11 signaling pathways were activated in the kidney stone model group, and the expression of the ferroptosis marker proteins SLC7A11 and GPX4 was significantly reduced, while the expression of ACSL4 was significantly increased. The expression of the iron transport-related proteins CP and TF increased significantly, and Fe²⁺ accumulated in the cell. The expression of HMGB1 increased significantly. In addition, the level of intracellular oxidative stress was increased. The gene with the most significant difference caused by CaOx crystals in HK-2 cells was ANKRD1. Silencing or overexpression of ANKRD1 by lentiviral infection technology regulated the expression of the p53/SLC7A11 signaling pathway, which regulated the ferroptosis induced by CaOx crystals. In conclusion, CaOx crystals can mediate ferroptosis through the Nrf2/HO-1 and p53/SLC7A11 pathways, thereby weakening the resistance of HK-2 cells to oxidative stress and other unfavorable factors, enhancing cell damage, and increasing crystal adhesion and CaOx crystal deposition in the kidney. ANKRD1 participates in the formation and development of CaOx kidney stones by activating ferroptosis mediated by the p53/SLC7A11 pathway.     

H2O2 down-regulates SIRT7’s protective role of endothelial premature dysfunction via microRNA-335-5p

Endothelial senescence is believed to constitute the initial pathogenesis of the atherosclerotic cardiovascular disease (ASCVD). MicroRNA-335-5p (miR-335-5p) expression is significantly up-regulated in oxidative stress-induced endothelial cells (ECs). Sirtuin7 (SIRT7) is considered to prevent EC senescence, yet data on its response to ASCVD risk factors are limited. The present study analyzed the elevated levels of miR-335-5p and the decreased levels of SIRT7 in human umbilical vein endothelial cells (HUVECs), and found that high glucose, tumor necrosis factor-α (TNF-α), and H₂O₂ are the three contributing factors that induced cellular senescence. The current study also assessed premature endothelial senescence and decreased proliferation, adhesion, migration, and nitric oxide (NO) secretion in HUVECs with these risk factors together with SIRT7–siRNA transfection. It found that the miR-335-5p inhibitor attenuated the down-regulation of SIRT7 expression induced by oxidative stress in HUVECs, and SIRT7 overexpression exerts a rescue effect against miR-335-5p-induced endothelial dysfunction. Furthermore, the direct binding of miR-335-5p to SIRT7 was observed in human embryonic kidney cells 293T (HEK 293T). Therefore, it can be inferred that miR-335-5p down-regulates the expression of SIRT7 in human cells. Current findings may provide deeper insights into the underlying mechanisms of endothelial senescence and potential therapeutic targets of ASCVD as well as other age-related diseases.     

LncRNA TUG1 attenuates ischaemia-reperfusion-induced apoptosis of renal tubular epithelial cells by sponging miR-144-3p via targeting Nrf2

Renal ischaemia/reperfusion (I/R) injury may induce kidney damage and dysfunction, in which oxidative stress and apoptosis play important roles. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are reported to be closely related to renal I/R, but the specific molecular mechanism is still unclear. The purpose of this research was to explore the regulatory effect of lncRNA TUG1 on oxidative stress and apoptosis in renal I/R injury. This research revealed that in renal I/R injury and hypoxia/reperfusion (H/R) injury in vitro, the expression level of lncRNA TUG1 was upregulated, and oxidative stress levels and apoptosis levels were negatively correlated with the expression level of lncRNA TUG1. Using bioinformatics databases such as TargetScan and microRNA.org, microRNA-144-3p (miR-144-3p) was predicted to be involved in the association between lncRNA TUG1 and Nrf2. This study confirmed that the level of miR-144-3p was significantly reduced following renal I/R injury and H/R injury in vitro, and miR-144-3p was determined to target Nrf2 and inhibit its expression. In addition, lncRNA TUG1 can reduce the inhibitory effect of miR-144-3p on Nrf2 by sponging miR-144-3p. In summary, our research shows that lncRNA TUG1 regulates oxidative stress and apoptosis during renal I/R injury through the miR-144-3p/Nrf2 axis, which may be a new treatment target for renal I/R injury.     

miR-23b-3p regulates apoptosis and autophagy via suppressing SIRT1 in lens epithelial cells

Age-related cataract is one of the prior causes of blindness and the incidence rates of cataract are even rising. Oxidative stress plays an important role in the pathogenesis of cataracts. Under oxidative stress, lens epithelial cell (LEC cell) apoptosis is activated, which might lead to the opacity of the lens and accelerate the progression of cataract development. Meanwhile, autophagy is also active to face oxidative stress. miRNAs have been reported to involve cataract. However, the underlying mechanism is not clear. The present study aimed to investigate the regulatory effect of miR23b-3p on apoptosis and autophagy in LEC cells under oxidative stress. The expression levels of miR-23b-3p were examined in age-related cataract tissues and LEC cells treated with hydrogen peroxide, showing that miR23b-3p expression levels were upregulated. Knockdown of miR23b-3p expression in LEC cells brought about apoptosis significantly decreased while autophagy significantly increased during hydrogen peroxide. We predicted microRNA miRNA-23b-3p might participate in regulating silent information regulator 1 (SIRT1) by bioinformatics database of TargetScan. Luciferase reporter assays confirmed that miRNA-23b-p could suppress SIRT1 expression by binding its 3′UTR. In addition, overexpression or knockdown of miR-23b-3p could decrease or increase SIRT1 expression, which indicated that Mir-23b-3p could suppress SIRT1 expression. In addition, enhanced SIRT1 could attenuate the regulation of cell apoptosis and autophagy induced by overexpression of miR-23b-3p. Taken together, our findings revealed that miR-23b-3p regulated apoptosis and autophagy via suppressing SIRT1 in LEC cell under oxidative stress, which could provide new ideas for clinical treatment of cataract.     

Fibulin7 aggravates calcium oxalate-induced acute kidney injury by binding to calcium oxalate crystals

Fibulin7 (Fbln7) is a matricellular protein that is structurally similar to short fibulins but does not possess elastogenic abilities. Fbln7 is localized on the cell surface of the renal tubular epithelium in the adult kidney. We previously reported that Fbln7 binds artificial calcium phosphate particles in vitro, and that heparin counteracts this binding by releasing Fbln7 from the cell surface. Fbln7 gene (Fbln7) deletion in vivo decreased interstitial fibrosis and improved renal function in a high phosphate diet-induced chronic kidney disease mouse model. However, the contribution of Fbln7 during acute injury response remains largely unknown. We hypothesized that Fbln7 serves as an exacerbating factor in acute kidney injury (AKI). We employed three AKI models in vivo and in vitro, including unilateral ureteral obstruction (UUO), cisplatin-induced AKI, and calcium oxalate (CaOx)-induced AKI. Here, we report that Fbln7KO mice were protected from kidney damage in a CaOx-induced AKI model. Using HEK293T cells, we found that Fbln7 overexpression enhanced the CaOx-induced upregulation of EGR1 and LAMB3, and that heparin treatment canceled this effect. Interestingly, the protective function observed in Fbln7KO kidneys was limited to the CaOx-induced AKI model, while Fbln7KO mice were not protected against UUO-induced renal fibrosis or cisplatin-induced renal tubular damage. Taken together, our study indicates that Fbln7 mediates the local deposition of CaOx and damages the renal tubular epithelium. Releasing Fbln7 from the cell surface via heparin/heparin derivatives or Fbln7 inhibitory antibodies may provide a general strategy to mitigate calcium crystal-induced kidney injuries.     

MicroRNA-22 inhibition prevents doxorubicin-induced cardiotoxicity via upregulating SIRT1

Oxidative stress and cardiomyocyte apoptosis contributed to the progression of doxorubicin (Dox)-induced cardiotoxicity. Recent studies identified microRNA-22 (miR-22) as a cardiac- and skeletal muscle-enriched microRNA that functioned as a key regulator in stress-induced cardiac injury. The present study aimed to investigate the role and possible mechanism of miR-22 on Dox-induced oxidative stress and cardiomyocyte apoptosis. Mice were exposed to reduplicative injections of Dox (i.p., 4 mg/kg) weekly for consecutive 4 weeks to generate Dox-induced cardiotoxicity. Herein, we found that miR-22 level was significantly increased in murine hearts subjected to chronic Dox treatment. MiR-22 inhibition attenuated oxidative stress and cardiomyocyte apoptosis in vivo and in vitro, thereby preventing Dox-induced cardiac dysfunction. Mechanistically, we observed that miR-22 directly bound to the 3′-UTR of Sirt1 and caused SIRT1 downregulation. Conversely, miR-22 antagomir upregulated SIRT1 expression and SIRT1 inhibitor abolished the beneficial effects of miR-22 antagomir. In conclusion, miR-22 inhibition prevented oxidative stress and cardiomyocyte apoptosis via upregulating SIRT1 and miR-22 might be a new target for treating Dox-induced cardiotoxicity.     

MiR-150-5p protects against septic acute kidney injury via repressing the MEKK3/JNK pathway

BackgroundSeptic acute kidney injury (AKI) is associated with increased morbidity and mortality in critically ill patients. MicroRNA is reportedly involved in sepsis-induced organ dysfunction, while the role of miR-150 in septic AKI remains ambiguous.MethodsQuantitative real-time PCR (qRT-PCR) was carried out to examine miR-150-5p expression in both septic AKI patients and volunteers without septic AKI. Lipopolysaccharide (LPS) was used to treat renal tubular epithelial cell line HK-2 and C57/BL6 mice to establish in vitro and in vivo sepsis-induced AKI models. Cell apoptosis was determined using TdT-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry. Cell viability was tested using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Renal pathological changes were examined via Hematoxylin-Eosin (H&E) staining, and renal function was measured via blood urea nitrogen (BUN) and creatinine (Cre) measurements. The MEKK3/JNK profile and oxidative stress markers (including COX2 and iNOS) were examined by immunoblot analysis, and the expression levels of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and oxidative stress markers (MDA, SOD, and CAT) were evaluated by ELISA.ResultsMiR-150-5p was down-regulated in the serum of patients with septic AKI (compared to healthy volunteers). Moreover, miR-150-5p levels were lower in LPS-treated HK-2 cell lines and in the septic AKI mouse model. Additionally, Stat-3 activation mediated the decrease of miR-150-5p. Functionally, miR-150-5p agomir attenuated LPS-induced apoptosis in HK-2 cells, in addition to renal inflammatory responses and oxidative stress. In contrast, inhibition of miR-150-5p aggravated LPS-induced apoptosis, inflammatory reactions and oxidative stress. Furthermore, miR-150-5p agomir decreased BUN and Scr levels in the septic AKI mice model repressed TNF-α, IL-6 and IL-1β, and up-regulated SOD and CAT down-regulated MDA in the kidney tissues. Moreover, miR-150-5p was identified as a target gene for Stat3, and the overexpression of Stat3 partially promoted the effect of down-regulating miR-150-5p on LPS-induced HK2 cell injury. Mechanistically, the MEKK3/JNK pathway was identified as a functional target of miR-150-5p, and the knockdown of MEKK3 showed protective effects against LPS mediated HK-2 cell apoptosis.ConclusionStat3-mediated miR-150-5p exerted protective effects in sepsis-induced acute kidney injury by regulating the MEKK3/JNK pathway.     

MicroRNA-590-3P suppresses cell survival and triggers breast cancer cell apoptosis via targeting sirtuin-1 and deacetylation of p53

Downregulation of microRNA-590-3p (miR-590-3p) is a frequently occurring, nonphysiological event which is observed in several human cancers, especially breast cancer. However, the significance of miR-590-3p still remain unclear in the progression of this disease. This study explored the role of miR-590-3p in apoptosis of breast cancer cells. Gene expression of miR-590-3p, Sirtuin-1 (SIRT1), Bcl-2 associated X protein (BAX), and p21 was evaluated with real-time polymerase chain reaction (PCR) and SIRT1 protein expression was assessed by Western blot analysis in breast cancer cell lines. Bioinformatics analysis and luciferase reporter assay were used to evaluate targeting of SIRT1 messenger RNA (mRNA) by miR-590-3p. Cells were transfected with miR-590-3p mimic and inhibitor and their effects on the expression and activity of SIRT1 were evaluated. The effects of miR-590-3p upregulation on the acetylation of p53 as well as cell viability and apoptosis were assessed by Western blot analysis, WST-1 assay, and flow cytometry, respectively. miR-590-3p expression was considerably downregulated in breast cancer cells which was accompanied by upregulation of SIRT1 expression. SIRT1 was recognized as a direct target for miR-590-3p in breast cancer cells and its protein expression and activity was dramatically inhibited by the miR-590-3p. In addition, there was an increase in p53 and its acetylated form that ultimately led to upregulation of BAX and p21 expression, suppression of cell survival, and considerable induction of apoptosis in breast cancer cells. These findings suggest that miR-590-3p exerts tumor-suppressing effects through targeting SIRT1 in breast cancer cells, which makes it a potential therapeutic target for developing more efficient treatments for breast cancer.     

High Sodium-Induced Oxidative Stress and Poor Anticrystallization Defense Aggravate Calcium Oxalate Crystal Formation in Rat Hyperoxaluric Kidneys

Enhanced sodium excretion is associated with intrarenal oxidative stress. The present study evaluated whether oxidative stress caused by high sodium (HS) may be involved in calcium oxalate crystal formation. Male rats were fed a sodium-depleted diet. Normal-sodium and HS diets were achieved by providing drinking water containing 0.3% and 3% NaCl, respectively. Rats were fed a sodium-depleted diet with 5% hydroxyl-L-proline (HP) for 7 and 42 days to induce hyperoxaluria and/or calcium oxalate deposition. Compared to normal sodium, HS slightly increased calcium excretion despite diuresis; however, the result did not reach statistical significance. HS did not affect the hyperoxaluria, hypocalciuria or supersaturation caused by HP; however, it increased calcium oxalate crystal deposition soon after 7 days of co-treatment. Massive calcium oxalate formation and calcium crystal excretion in HS+HP rats were seen after 42 days of treatment. HP-mediated hypocitraturia was further exacerbated by HS. Moreover, HS aggravated HP-induced renal injury and tubular damage via increased apoptosis and oxidative stress. Increased urinary malondialdehyde excretion, in situ superoxide production, NAD(P)H oxidase and xanthine oxidase expression and activity, and decreased antioxidant enzyme expression or activity in the HS+HP kidney indicated exaggerated oxidative stress. Interestingly, this redox imbalance was associated with reduced renal osteopontin and Tamm-Horsfall protein expression (via increased excretion) and sodium-dependent dicarboxylate cotransporter NaDC-1 upregulation. Collectively, our results demonstrate that a HS diet induces massive crystal formation in the hyperoxaluric kidney; this is not due to increased urinary calcium excretion but is related to oxidative injury and loss of anticrystallization defense.     

Pterostilbene and allopurinol reduce fructose-induced podocyte oxidative stress and inflammation via microRNA-377

High dietary fructose is an important causative factor in the development of metabolic syndrome-associated glomerular podocyte oxidative stress and injury. Here, we identified microRNA-377 (miR-377) as a biomarker of oxidative stress in renal cortex of fructose-fed rats, which correlated with podocyte injury and albuminuria in metabolic syndrome. Fructose feeding increased miR-377 expression, decreased superoxide dismutase (SOD) expression and activity, and caused O₂⁻ and H₂O₂ overproduction in kidney cortex or glomeruli of rats. This reactive oxygen species induction increased p38 MAPK phosphorylation and thioredoxin-interacting protein (TXNIP) expression and activated the NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome to produce interleukin-1β in kidney glomeruli of fructose-fed rats. These pathological processes were further evaluated in cultured differentiated podocytes exposed to 5 mM fructose, or transfected with miR-377 mimic/inhibitor and TXNIP siRNA, or co-incubated with p38 MAPK inhibitor, demonstrating that miR-377 overexpression activates the O₂⁻/p38 MAPK/TXNIP/NLRP3 inflammasome pathway to promote oxidative stress and inflammation in fructose-induced podocyte injury. Antioxidants pterostilbene and allopurinol were found to ameliorate fructose-induced hyperuricemia, podocyte injury, and albuminuria in rats. More importantly, pterostilbene and allopurinol inhibited podocyte miR-377 overexpression to increase SOD1 and SOD2 levels and suppress the O₂⁻/p38 MAPK/TXNIP/NLRP3 inflammasome pathway activation in vivo and in vitro, consistent with the reduction of oxidative stress and inflammation. These findings suggest that miR-377 plays an important role in glomerular podocyte oxidative stress, inflammation, and injury driven by high fructose. Inhibition of miR-377 by antioxidants may be a promising therapeutic strategy for the prevention of metabolic syndrome-associated glomerular podocyte injury.     

A novel fine tuning scheme of miR-200c in modulating lung cell redox homeostasis

Oxidative stress induces miR-200c, the predominant microRNA (miRNA) in lung tissues; however, the antioxidant role and biochemistry of such induction have not been clearly defined. Therefore, a lung adenocarcinoma cell line (A549) and a normal lung fibroblast (MRC-5) were used as models to determine the effects of miR-200c expression on lung antioxidant response. Hydrogen peroxide (H₂O₂) upregulated miR-200c, whose overexpression exacerbated the decrease in cell proliferation, retarded the progression of cells in the G2/M-phase, and increased oxidative stress upon H₂O₂ stimulation. The expression of three antioxidant proteins, superoxide dismutase (SOD)-2, haem oxygenase (HO)-1, and sirtuin (SIRT) 1, was reduced upon H₂O₂ stimulation in miR-200c-overexpressed A549 cells. This phenomenon of increased oxidative stress and antioxidant protein downregulation also occurs simultaneously in miR-200c overexpressed MRC-5 cells. Molecular analysis revealed that miR-200c inhibited the gene expression of HO-1 by directly targeting its 3′-untranslated region. The downregulation of SOD2 and SIRT1 by miR-200c was mediated through zinc finger E-box-binding homeobox 2 (ZEB2) and extracellular signal-regulated kinase 5 (ERK5) pathways, respectively, where knockdown of ZEB2 or ERK5 decreased the expression of SOD2 or SIRT1 in A549 cells. LNA anti-miR-200c transfection in A549 cells inhibited the endogenous miR-200c expression, resulting in increased expressions of antioxidant proteins, reduced oxidative stress and recovered cell proliferation upon H₂O₂ stimulation. These findings indicate that miR-200c fine-tuned the antioxidant response of the lung cells to oxidative stress through several pathways, and thus this study provides novel information concerning the role of miR-200c in modulating redox homeostasis of lung.     

MicroRNA-363-3p/sphingosine-1-phosphate receptor 1 axis inhibits sepsis-induced acute lung injury via the inactivation of nuclear factor kappa-B ligand signaling

Infection-associated inflammation and coagulation are critical pathologies in sepsis-induced acute lung injury (ALI). This study aimed to investigate the effects of microRNA-363-3p (miR-363-3p) on sepsis-induced ALI and explore the underlying mechanisms. A cecal ligation and puncture-induced septic mouse model was established. The results of this study suggested that miR-363-3p was highly expressed in lung tissues of septic mice. Knockdown of miR-363-3p attenuated sepsis-induced histopathological damage, the inflammation response and oxidative stress in lung tissues. Furthermore, knockdown of miR-363-3p reduced the formation of platelet-derived microparticles and thrombin generation in blood samples of septic mice. Downregulation of miR-363-3p suppressed sphingosine-1-phosphate receptor 1 (S1PR1) expression in lung tissues and subsequently inactivated the nuclear factor kappa-B ligand (NF-κB) signaling. A luciferase reporter assay confirmed that miR-363-3p directly targeted the 3’-untranslated region of the mouse S1pr1 mRNA. Collectively, our study suggests that inactivation of NF-κB signaling is involved in the miR-363-3p/S1PR1 axis-mediated protective effect on septic ALI.     

Activation of liver X receptor suppresses osteopontin expression and ameliorates nephrolithiasis

Nephrolithiasis is a common disease of the urinary system, of which idiopathic calcium oxalate (CaOx) kidney stones, in particular, are one of the special types. In the initial stages of CaOx kidney stone formation, Randall's plaques (RPs) develop. Liver X receptors (LXRs) inhibit oxidative stress and inflammatory in other diseases; nevertheless, the role of LXRs in nephrolithiasis has yet to be elucidated. In this study, the role of LXRs in the progression of RP formation was investigated. Microarray analysis revealed that LXR/RXR levels were significantly greater in low-plaque tissues (<5%) than in high-plaque tissues (>5%), confirming the link between LXR activation and RP formation. Correspondingly, expression levels of two LXR target genes, LXRα and LXRβ, were lower in high-plaque tissues than in low-plaque tissues. In vitro, LXR agonist alleviated calcium oxalate monohydrate-induced cellular calcium deposits and apoptosis. LXR activation decreased reactive oxygen species production and gene expression of inflammatory mediators, including osteopontin that has recently been demonstrated to correlate with the development of RPs. Moreover, p38 MAPK and JNK signaling may mediate LXR-regulated expression in HK-2 cells. In an animal model, the deposition was reduced by activating LXR, and osteopontin expression was also inhibited. Our findings suggest a role for LXRs in the progression of idiopathic CaOx kidney stones; LXR agonists may have therapeutic potential for the treatment of nephrolithiasis.     

MicroRNA-135b-5p Downregulation Causes Antidepressant Effects by Regulating SIRT1 Expression

Depression is a serious and potentially life-threatening mental illness. Recently, the role of sirtuin 1 (SIRT1) in chronic unpredictable mild stress (CUMS) management has been examined. The present study explored and clarified whether microRNA (miR)-135b-5p could play a role in depression by regulating the expression of SIRT1. SIRT1 was identified as the target gene of miR-135b-5p using TargetScan and the dual luciferase reporter assay. In addition, the expression levels of SIRT1 were significantly reduced in mouse peripheral blood and hippocampal tissue samples, while the expression of miR-135b-5p exhibited the opposite effects. Subsequently, the effects of miR-135b-5p inhibition were investigated in mice with depression. The results indicated that the miR-135b-5p inhibitor significantly increased the weight loss induced by CUMS compared with the model group, while reducing the expression levels of miR-135b-5p and further alleviating the depression-like behavior induced by CUMS. Concomitantly, the results indicated that the miR-135b-5p inhibitor inhibited CUMS-induced hippocampal cell apoptosis and significantly reduced the expression levels of cleaved caspase-3 and the ratio of cleaved caspase-3/caspase-3. Moreover, the miR-135b-5p inhibitor significantly reduced the CUMS-induced increase of the inflammatory factors IL-1β, IL-6 and TNF-α in the hippocampal mouse samples, while significantly increasing the expression levels of SIRT1. Finally, the results demonstrated that all the effects of the miR-135b-5p inhibitor on CUMS-induced mice were significantly reversed by SIRT1 silencing. In conclusion, the present study indicated that the miR-135b-5p/SIRT1 pathway was a key mediator of antidepressant effects induced in depressed mice. Therefore, it could be considered a potential therapeutic target for the treatment of CUMS-induced depression.

     

microRNA-340-5p inhibits hypoxia/reoxygenation-induced apoptosis and oxidative stress in cardiomyocytes by regulating the Act1/NF-κB pathway

MicroRNAs (miRNAs) have been reported to play critical roles in the occurrence, progression, and treatment of many cardiovascular diseases. However, the molecular mechanism by which miRNA regulates target gene expression in ischemia-reperfusion (I/R) injury in acute myocardial infarction (AMI) is not entirely clear. MiR-340-5p was reported to be downregulated in acute ischemic stroke. However, it still remains unknown whether miR-340-5p is mediated in the pathogenesis process of I/R injury after AMI. In the present study, male C57BL/6 J mice and H9C2 cardiomyocytes were used as experimental models. Real-time polymerase chain reaction analysis, Western blot analysis, and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling immunofluorescence staining assay were conducted to examine related indicators in the study. We confirmed that the expression of miR-340-5p is downregulated after I/R in AMI mice and hypoxia/reperfusion (H/R)-induced cardiomyocytes. miR-340-5p could inhibit apoptosis and oxidative stress in H/R-induced H9C2 cells via downregulating activator 1 (Act1). The inhibiting action of miR-340-5p on H/R-induced apoptosis and oxidative stress in cardiomyocytes was partially reversed after Act1 overexpression. Moreover, the results showed that the NF-κB pathway may be mediated in the role of miR-340-5p on H/R-induced cardiomyocyte apoptosis and oxidative stress. We demonstrated that upregulation of miR-340-5p suppresses apoptosis and oxidative stress induced by H/R in H9C2 cells by inhibiting Act1. Therapeutic strategies that target miR-340-5p, Act1, and the NF-κB pathway could be beneficial for the treatment of I/R injury after AMI.