Hsp22 ameliorates lipopolysaccharide-induced myocardial injury by inhibiting inflammation, oxidative stress, and apoptosis

The ischemia-enhanced myocardial infarction protection-related lncRNA protects against acute myocardial infarction

Long non-coding RNA RP11-64B16.4 (myocardial infarction protection-related lncRNA [MIPRL]) is among the most abundant and the most upregulated lncRNAs in ischemic human hearts. However, its role in ischemic heart disease is unknown. We found MIPRL was conserved between human and mouse and its expression was increased in mouse hearts after acute myocardial infarction (AMI) and in cultured human and mouse cardiomyocytes after hypoxia. The infarcted size, cardiac cell apoptosis, cardiac dysfunction, and cardiac fibrosis were aggravated in MIPRL knockout mice after AMI. The above adverse results could be reversed by re-expression of MIPRL via adenovirus expressing MIPRL. Both in vitro and in vivo, we identified that heat shock protein beta-8 (HSPB8) was a target gene of MIPRL, which was involved in MIPRL-mediated anti-apoptotic effects on cardiomyocytes. We further discovered that MIPRL could combine with the messenger RNA (mRNA) of HSPB8 and increase its expression in cardiomyocytes by enhancing the stability of HSPB8 mRNA. In summary, we have found for the first time that the ischemia-enhanced lncRNA MIPRL protects against AMI via its target gene HSPB8. MIPRL might be a novel promising therapeutic target for ischemic heart diseases such as AMI.

Effects of grafting on chemical constituents, toxicological properties, antithrombotic activity, and myocardial infarction protection of styrax secreted from the trunk of Liquidambar orientalis Mill

Styrax, the balsam refined from the trunk of Liquidambar orientalis Mill. has a variety of applications in the perfumery and medical industry, especially for use in traditional Chinese medicine. However, the resources of styrax are in shortage due to being endangered of this plant. Grafting can improve the adaptability of plants to unfavorable environmental conditions. We tried to graft the L. orientalis Mill. on L. formosana Hance which was widely distributed in Jiangsu and Zhejiang provinces of China in an attempt to obtain styrax from grafted L. orientalis Mill. (grafted styrax, SG). Whether SG can become an alternative application of commercially available styrax (SC) need be further investigated. The components of SG were analyzed by GC-MS, and the results showed that the chromatograms of SG, SC, and styrax standard (SS) were consistent. The ration of 12 major chemical components based peak area in SG, SC, and SS were 93.95%, 94.24%, and 95.86% respectively. The assessment of toxicity, antithrombotic activity, and myocardial infarction protection of SG and SC was evaluated by using the zebrafish model, the results showed that SG and SC have the similar toxicological properties as evidenced by acute toxicity test, developmental toxicity and teratogenicity, and long-term toxicity test. Both SG and SC significantly decreased the thrombosis and increased blood flow velocity of zebrafish induced by adrenaline hydrochloride, inhibited myocardial apoptosis, myocardial infarction and myocardial inflammation in zebrafish induced by isoproterenol hydrochloride. Moreover, SG had an obvious improvement effect on cardiac output, while SC has no effect. Collectively, SG is similar to SC in chemical composition, toxicological properties, antithrombotic activity, and myocardial infarction protection effects, and may be used as a substitute for styrax to reduce the collection for wild L. orientalis Mill. and increase the available styrax resources.

The role of heat shock proteins in the pathogenesis of heart failure (Review)

The influence of heat shock proteins (HSPs) on protein quality control systems in cardiomyocytes is currently under investigation. The effect of HSPs on the regulated cell death of cardiomyocytes (CMCs) is of great importance, since they play a major role in the implementation of compensatory and adaptive mechanisms in the event of cardiac damage. HSPs mediate a number of mechanisms that activate the apoptotic cascade, playing both pro‑ and anti‑apoptotic roles depending on their location in the cell. Another type of cell death, autophagy, can in some cases lead to cell death, while in other situations it acts as a cell survival mechanism. The present review considered the characteristics of the expression of HSPs of different molecular weights in CMCs in myocardial damage caused by heart failure, as well as their role in the realization of certain types of regulated cell death.

NLRP3 inflammasome involves in the pathophysiology of sepsis-induced myocardial dysfunction by multiple mechanisms

Sepsis-induced myocardial dysfunction (SIMD) is one of the serious health-affecting problems worldwide. At present, the mechanisms of SIMD are still not clearly elucidated. The NOD-like receptor protein 3 (NLRP3) inflammasome has been assumed to be involved in the pathophysiology of SIMD by regulating multiple biological processes. NLRP3 inflammasome and its related signaling pathways might affect the regulation of inflammation, autophagy, apoptosis, and pyroptosis in SIMD. A few molecular specific inhibitors of NLRP3 inflammasome (e.g., Melatonin, Ulinastatin, Irisin, Nifuroxazide, and Ginsenoside Rg1, etc.) have been developed, which showed a promising anti-inflammatory effect in a cellular or animal model of SIMD. These experimental findings indicated that NLRP3 inflammasome could be a promising therapeutic target for SIMD treatment. However, the clinical translation of NLRP3 inhibitors for treating SIMD still requires robust in vivo and preclinical trials.

Involvement of the heat shock response (HSR) regulatory pathway in cadmium-elicited cerebral damage

The heat shock response (HSR) is a cellular protective mechanism that is characterized by the induction of heat shock transcription factors (HSFs) and heat shock proteins (HSPs) in response to diverse cellular and environmental stressors, including cadmium (Cd). However, little is known about the relationship between the damaging effects of Cd and the HSR pathway in the chicken cerebrum following Cd exposure. To explore whether Cd exposure elicits cerebral damage and triggers the HSR pathway, chicks were exposed to Cd in the daily diet at different concentrations (35, 70, or 140 mg/kg feed) for 90 days, while a control group was fed the standard diet without Cd. Histopathological examination of cerebral tissue from Cd-exposed chickens showed neuronal damage, as evidenced by swelling and degeneration of neurons, loss of neurons, and capillary damage. Cd exposure significantly increased mRNA expression of HSF1, HSF2, and HSF3, and mRNA and protein expression of three major stress-inducible HSPs (HSP60, HSP70, and HSP90). Moreover, Cd exposure differentially modulated mRNA expression of small HSP (sHSPs), most notably reducing expression of HSP27 (HSPB1). Furthermore, Cd exposure increased TUNEL-positive neuronal apoptotic cells and up-regulated protein expression of caspase-1, caspase-8, caspase-3, and p53, leading to apoptosis. Taken together, these data demonstrate that activation of the HSR and apoptotic pathways by Cd exposure is involved in Cd-elicited cerebral damage in the chicken. Synopsis for the graphical abstract Cadmium (Cd)-induced neuronal damage triggers the heat shock response (HSR) by activating heat shock transcription factors (HSFs) and subsequent induction of major heat shock proteins (notably, HSP60, HSP70, and HSP90). Moreover, Cd exposure activates caspase-1, caspase-8, caspase-3, and p53 protein, thereby resulting in neuronal apoptosis in the chicken brain.

Research Progress of Macromolecules in the Prevention and Treatment of Sepsis

Sepsis is associated with high rates of mortality in the intensive care unit and accompanied by systemic inflammatory reactions, secondary infections, and multiple organ failure. Biological macromolecules are drugs produced using modern biotechnology to prevent or treat diseases. Indeed, antithrombin, antimicrobial peptides, interleukins, antibodies, nucleic acids, and lentinan have been used to prevent and treat sepsis. In vitro, biological macromolecules can significantly ameliorate the inflammatory response, apoptosis, and multiple organ failure caused by sepsis. Several biological macromolecules have entered clinical trials. This review summarizes the sources, efficacy, mechanism of action, and research progress of macromolecular drugs used in the prevention and treatment of sepsis.

Functional Diversity of Mammalian Small Heat Shock Proteins: A Review

The small heat shock proteins (sHSPs), whose molecular weight ranges from 12∼43 kDa, are members of the heat shock protein (HSP) family that are widely found in all organisms. As intracellular stress resistance molecules, sHSPs play an important role in maintaining the homeostasis of the intracellular environment under various stressful conditions. A total of 10 sHSPs have been identified in mammals, sharing conserved α-crystal domains combined with variable N-terminal and C-terminal regions. Unlike large-molecular-weight HSP, sHSPs prevent substrate protein aggregation through an ATP-independent mechanism. In addition to chaperone activity, sHSPs were also shown to suppress apoptosis, ferroptosis, and senescence, promote autophagy, regulate cytoskeletal dynamics, maintain membrane stability, control the direction of cellular differentiation, modulate angiogenesis, and spermatogenesis, as well as attenuate the inflammatory response and reduce oxidative damage. Phosphorylation is the most significant post-translational modification of sHSPs and is usually an indicator of their activation. Furthermore, abnormalities in sHSPs often lead to aggregation of substrate proteins and dysfunction of client proteins, resulting in disease. This paper reviews the various biological functions of sHSPs in mammals, emphasizing the roles of different sHSPs in specific cellular activities. In addition, we discuss the effect of phosphorylation on the function of sHSPs and the association between sHSPs and disease.

Zataria multiflora and its constituent, carvacrol, counteract sepsis-induced aortic and cardiac toxicity in rat: Involvement of nitric oxide and oxidative stress

BACKGROUND

Zataria multiflora and carvacrol showed various pharmacological properties including anti-inflammatory and anti-oxidant effects. However, up to now no studies have explored its potential benefits in ameliorating sepsis-induced aortic and cardiac injury. Thus, this study aimed to investigate the effects of Z. multiflora and carvacrol on nitric oxide (NO) and oxidative stress indicators in lipopolysaccharide (LPS)-induced aortic and cardiac injury.

METHODS

Adult male Wistar rats were assigned to: Control, lipopolysaccharide (LPS) (1 mg/kg, intraperitoneal (i.p.)), and Z. multiflora hydro-ethanolic extract (ZME, 50-200 mg/kg, oral)- and carvacrol (25-100 mg/kg, oral)-treated groups. LPS was injected daily for 14 days. Treatment with ZME and carvacrol started 3 days before LPS administration and treatment continued during LPS administration. At the end of the study, the levels of malondialdehyde (MDA), NO, thiols, and antioxidant enzymes were evaluated.

RESULTS

Our findings showed a significant reduction in the levels of superoxide dismutase (SOD), catalase (CAT), and thiols in the LPS group, which were restored by ZME and carvacrol. Furthermore, ZME and carvacrol decreased MDA and NO in cardiac and aortic tissues of LPS-injected rats.

CONCLUSIONS

The results suggest protective effects of ZME and carvacrol on LPS-induced cardiovascular injury via improved redox hemostasis and attenuated NO production. However, additional studies are needed to elucidate the effects of ZME and its constituents on inflammatory responses mediated by LPS.

Dried root of Rehmannia glutinosa extracts prevents steroid-induced avascular necrosis of femoral head by activating the wingless-type (Wnt)/β-catenin signal pathway

Steroid-induced avascular necrosis of femoral head (SANFH) is one of the most common complications caused by long-term or excessive clinical use of glucocorticoids. This study aimed to investigate the effects of dried root of Rehmannia glutinosa extracts (DRGE) in SANFH. First, SANFH rat model was established by dexamethasone (Dex). Tissue change and proportion of empty lacunae were detected by hematoxylin and eosin staining. Protein levels were detected by western bloting analysis. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was performed to assess apoptosis of femoral head tissue. Cell viability and apoptosis of MC3T3-E1 cells were assessed by Cell Counting Kit-8 assay and flow cytometry. ALP activity and cell mineralization were detected by ALP staining assay and Alizarin red staining. The findings showed that DRGE improved tissue damage, inhibited apoptosis, and promoted osteogenesis in SANFH rats. In vitro, DRGE increased cell viability, inhibited cell apoptosis, promoted osteoblast differentiation, reduced the levels of p-GSK-3β/GSK-3β, but increased the levels of β-catenin in cells treated with Dex. Furthermore, DKK-1, an inhibitor of the wingless-type (Wnt)/β-catenin signaling pathway, reversed the effect of DRGE on cell apoptosis and ALP activity in cells treated with Dex. In conclusion, DRGE prevents SANFH by activating the Wnt/β-catenin signaling pathway, indicating that DRGE may be a hopeful choice drug to prevent and treat patients with SANFH.

Hsp22 pretreatment protection against LPS-induced hippocampal injury by alleviating neuroinflammation and apoptosis by regulating the NLRP3/Caspase1/IL-1β signaling pathway in mice

Neuroinflammation is an important reason for the occurrence and development of cognitive impairment. The Lentiviral vector Hsp22 was constructed for intracerebroventricular injection pretreatment, LPS was used to induce the cognitive impairment model in mice, and the Morris water maze was used to examine the changes in cognitive behavior in mice. LPS was used to induce BV-2 microglial cells, and plasmid pretreatment was used to overexpress Hsp22. HE staining, Nissl staining, immunohistochemistry, immunofluorescence, ELISA and protein blotting were used to examine microglial activation, changes in inflammatory factors, changes in pathway proteins and apoptosis. The results showed that LPS induced microglial expression of NLRP3/Caspase-1/IL-1β signaling pathway protein Iba1, and the inflammatory protein and inflammatory factors IL-1β, IL-6 and TNF-α, the expression of Bax increased significantly, Bcl2 expression decreased, and the learning and memory abilities of mice decreased significantly. Preconditioning with the Hsp22-overexpressing lentivirus attenuated LPS-induced activation of hippocampal microglia, the expression of inflammatory factors and pathway proteins, and apoptosis, and improved cognitive impairment in mice. In addition, plasmid-mediated Hsp22 overexpression reversed LPS-induced inflammation. These findings suggest that Hsp22 overexpression is a promising method for the treatment of cognitive impairment.

Lycorine protects against septic myocardial injury by activating AMPK-related pathways

Cardiac dysfunction is a common complication in patients with sepsis triggering high morbidity and mortality. Lycorine (LYC), the main effective monomer component extracted from Lycoris bulbs, possesses antiviral, anti-inflammatory, analgesic, liver protection properties. In this study, the effect of LYC pre- and post-treatment as well as the underlying mechanism were evaluated in the cecal ligation and puncture (CLP) model of Balb/c mice. The survival rate, anal temperature, sepsis score, blood biochemical/routine indicators, cardiac function, sepsis-related pathophysiological processes, and AMPK signaling in septic mice were observed by echocardiography, histological staining, western blot, qPCR, and etc. LYC pretreatment attenuated myocardial injury in septic mice by improving survival rate, sepsis score, blood biochemical/routine indicators, cardiac function and structure, inhibiting inflammation and oxidative stress, improving mitochondrial function, modulating endoplasmic reticulum stress, and activating AMPK pathway. In particular, AMPK deficiency and AMPK inhibitor (Compound C) partially reversed the protective effects of LYC in septic mice. In addition, LYC posttreatment also has slight protective phenotypes on septic myocardial injury, but the effect is not as ideal as pretreatment. Taken together, these findings suggest that LYC may be a potential drug for the treatment of sepsis.

Angiotensin-(1-7) ameliorates sepsis-induced cardiomyopathy by alleviating inflammatory response and mitochondrial damage through the NF-κB and MAPK pathways

BACKGROUND

There is no available viable treatment for Sepsis-Induced Cardiomyopathy (SIC), a common sepsis complication with a higher fatality risk. The septic patients showed an abnormal activation of the renin angiotensin (Ang) aldosterone system (RAAS). However, it is not known how the Ang II and Ang-(1-7) affect SIC.

METHODS

Peripheral plasma was collected from the Healthy Control (HC) and septic patients and Ang II and Ang-(1-7) protein concentrations were measured. The in vitro and in vivo models of SIC were developed using Lipopolysaccharide (LPS) to preliminarily explore the relationship between the SIC state, Ang II, and Ang-(1-7) levels, along with the protective function of exogenous Ang-(1-7) on SIC.

RESULTS

Peripheral plasma Ang II and the Ang II/Ang-(1-7) levels in SIC-affected patients were elevated compared to the levels in HC and non-SIC patients, however, the HC showed higher Ang-(1-7) levels. Furthermore, peripheral plasma Ang II, Ang II/Ang-(1-7), and Ang-(1-7) levels in SIC patients were significantly correlated with the degree of myocardial injury. Additionally, exogenous Ang-(1-7) can attenuate inflammatory response, reduce oxidative stress, maintain mitochondrial dynamics homeostasis, and alleviate mitochondrial structural and functional damage by inhibiting nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thus alleviating SIC.

CONCLUSIONS

Plasma Ang-(1-7), Ang II, and Ang II/Ang-(1-7) levels were regarded as significant SIC biomarkers. In SIC, therapeutic targeting of RAAS, for example with Ang-(1-7), may exert protective roles against myocardial damage.

Study of Therapeutic Mechanisms of Puerarin against Sepsis-Induced Myocardial Injury by Integrating Network Pharmacology, Bioinformatics Analysis, and Experimental Validation

Myocardial injury is the most prevalent and serious complication of sepsis. The potential of puerarin (Pue) to treat sepsis-induced myocardial injury (SIMI) has been recently reported. Nevertheless, the specific anti-SIMI mechanisms of Pue remain largely unclear. Integrating network pharmacology, bioinformatics analysis, and experimental validation, we aimed to clarify the anti-SIMI mechanisms of Pue, thereby furnishing novel therapeutic targets. Pue-associated targets were collected from HIT, GeneCards, SwissTargetPrediction, SuperPred, and CTD databases. SIMI-associated targets were acquired from GeneCards and DisGeNET. Differentially expressed genes (DEGs) were identified from GEO database. Potential anti-SIMI targets of Pue were determined using VennDiagram. ClusterProfiler was employed for GO and KEGG analyses. STRING database and Cytoscape were used for protein-protein interaction (PPI) network construction, and cytoHubba was used for hub target screening. PyMOL and AutoDock were utilized for molecular docking. An in vitro SIMI model was built to further verify the therapeutic mechanisms of Pue. Seventy-three Pue-SIMI-DEG intersecting target genes were obtained. GO and KEGG analyses revealed that the targets were principally concentrated in cellular response to chemical stress, response to oxidative stress (OS), and insulin and neurotrophin signaling pathways. Through PPI analysis and molecular docking, AKT1, CASP3, TP53, and MAPK3 were identified as the pivotal targets. In vivo experiments indicated that Pue promoted cell proliferation, downregulated AKT1, CASP3, TP53, and MAPK3, and inhibited inflammation, myocardial injury, OS, and apoptosis in the cell model. Pue might inhibit inflammation, myocardial injury, OS, and apoptosis to treat SIMI by reducing AKT1, CASP3, TP53, and MAPK3.

Resveratrol alleviates lipopolysaccharide-induced liver injury by inducing SIRT1/P62-mediated mitophagy in gibel carp (Carassius gibelio)

Introduction

Resveratrol (RES) is a polyphenol organic compound with antioxidant and anti-inflammatory properties. This study aimed to determine whether and how RES can alleviate liver injury in lipopolysaccharide (LPS)-induced gibel carp.

Methods

Gibel carp were fed a diet with or without RES and were cultured for 8 weeks, followed by LPS injection.

Results and discussion

The results suggested that RES attenuated the resulting oxidative stress and inflammation by activating the Nrf2/Keap1 pathway and inhibiting the NF-κB pathway, as confirmed by changes in oxidative stress, inflammation-related gene expression, and antioxidant enzyme activity. Furthermore, RES cleared damaged mitochondria and enhanced mitochondrial biogenesis to mitigate reactive oxygen species (ROS) accumulation by upregulating the SIRT1/PGC-1α and PINK1/Parkin pathways and reducing p62 expression. Overall, RES alleviated LPS-induced oxidative stress and inflammation in gibel carp through mitochondria-related mechanisms.

New insights into the regulation mechanism of Litopenaeus vannamei hepatopancreas after lipopolysaccharide challenge using transcriptome analyses

Litopenaeus vannamei (L. vannamei) is the most economically valuable cultured shrimp in the world, while Gram-negative bacteria infection causes huge economic losses to shrimp culture. In this study, we performed transcriptome sequencing of the hepatopancreas in L. vannamei after lipopolysaccharide (LPS, the cell wall component of Gram-negative bacteria) injection to investigate the response of shrimp under Gram-negative bacteria invasion. A total of 306 differentially expressed genes (DEGs) (70 up- and 236 down-regulated) were identified in the LPS treatment group (L group) when compared to their expression levels in the control group (C group). The oxidoreductase activity (GO:0016491) in the molecular function category was enriched in the LPS-responsive DEGs in GO annotation, and the metabolism of xenobiotics by cytochrome P450 (ko00980) was the most enriched pathway in KEGG annotation. The transcriptome profiling revealed that the toll like receptor, C-type lectin receptor, and β-1,3-glucan binding protein were involved in the recognition of LPS during its early invasion stage. Although LPS could reduce the metabolic ability of exogenous substances, induce inflammation and reduce antioxidant capacity, L. vannamei could maintain its homeostasis by improving immunity, enhancing anti-stress ability and reducing apoptosis. Our research provides the first transcriptome profiling for the L. vannamei hepatopancreas after LPS injection. These results could offer a valuable reference on the mechanism of shrimp against Gram-negative bacteria and could provide guidance for shrimp farming.

Omarigliptin alleviates cognitive dysfunction in Streptozotocin-induced diabetic mouse

Increasing epidemiological evidence supports the strong association between diabetes mellitus (DM) and cognitive dysfunction. Omarigliptin is a long-acting dipeptidyl peptidase 4 (DPP-4) inhibitor for the treatment of diabetes. However, the effect of Omarigliptin in diabetes-associated cognitive dysfunction has not been reported. In this study, we established an in vivo diabetic mice model through streptozotocin (STZ) treatment and investigated the therapeutic effect of Omarigliptin in diabetic mice. The results show that administration with Omarigliptin reduced the food and water intake of STZ-induced diabetic mice, accompanied by decreased blood glucose levels and increased serum insulin levels. The Y-Maze test demonstrated that Omarigliptin ameliorated cognitive dysfunction in STZ-induced diabetic mice. Omarigliptin presented a protective role in the brain, as shown by the decreased reactive oxygen species (ROS) level, increased NAD+/NADH ratio, adenosine triphosphate (ATP) level, and ATP synthase activity in the hippocampus. Omarigliptin induced the increased expression level of mitochondrial inner membrane protein sirtuin 3 (SIRT3) and regulated its substrates, including forkhead box O3a (FOXO3a) and superoxide dismutase 2 (SOD2). Furthermore, knockdown of SIRT3 abolished the protective effects of Omarigliptin on mitochondrial dysfunction and cognitive dysfunction in STZ-induced diabetic mice. Taken together, these findings suggest that Omarigliptin improved insulin sensitivity and cognitive function in STZ-induced diabetic mice. Mechanistically, SIRT3 expression is required for the effect of Omarigliptin. This study provided preclinical evidence that Omarigliptin has the neuroprotective effect to improve diabetes-associated cognitive dysfunction.

MCC950 ameliorates ventricular arrhythmia vulnerability induced by heart failure

MCC950, a specific NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inhibitor, has been reported to play a role in various cardiovascular diseases. However, its role in heart failure (HF)-induced ventricular arrhythmias (VAs) remains unclear. Hence, the present study aimed to clarify the role and underlying mechanisms of MCC950 in HF-induced VAs. Male C57BL/6 mice were induced with HF via transverse aortic constriction (TAC). Histological analysis, echocardiography, electrophysiological investigation, and western blot analysis were conducted to evaluate VA vulnerability induced by TAC and the potential mechanisms underlying the effects. MCC950 markedly improved cardiac function and decreased pulmonary edema induced by HF. Moreover, MCC950 also decreased VA vulnerability, as shown by the shortened QTc duration and action potential duration 90 (APD₉₀), reduced APD alternans threshold, and decreased VA induction rate. Furthermore, MCC950 treatment significantly reversed TAC-induced cardiac hypertrophy and fibrosis. In addition, MCC950 administration increased the protein levels of ion channels (Kv4.2, KChIP2, and Cav1.2). Mechanistically, the above changes induced by MCC950 were due to the inhibition of the NLRP3 inflammasome. As a specific NLRP3 inhibitor, MCC950 significantly decreased HF-induced VA vulnerability by reversing cardiac structural remodeling and electrical remodeling, and the mechanism through which MCC950 exhibited this effect was inhibition of NLRP3 inflammasome activation.

microRNA-135a-5p regulates NOD-like receptor family pyrin domain containing 3 inflammasome-mediated hypertensive cardiac inflammation and fibrosis via thioredoxin-interacting protein

Hypertension is a severe public health problem that induces cardiac injury with alterations of gene expressions. The current study sought to evaluate the mechanism of microRNA(miR)-135a-5p in NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediation of cardiac inflammation and hypertensive cardiac fibrosis. Firstly, hypertensive mouse models were established using angiotensin II (Ang II), followed by miR-135a-5p agomir treatment. Subsequently, mouse blood pressure and basic cardiac function indexes, histopathological changes, and cardiac fibrosis were all determined, in addition to detection of factors related to inflammation and fibrosis. Additionally, mice cardiac fibroblasts (CFs) were isolated and treated with Ang II. The binding relationship of miR-135a-5p and thioredoxin-interacting protein (TXNIP) was predicted and testified, while the interaction of TXNIP and NLRP3 was detected by means of a co-immunoprecipitation assay. It was found that miR-135a-5p was poorly-expressed in Ang II-treated mice and further exerted cardioprotective effects against hypertensive heart diseases. Moreover, over-expression of miR-135a-5p resulted in inhibition of inflammatory infiltration and almost eliminated cardiac fibrosis, as evidenced by decreased Collagen (COL)-I, COL-III, a-smooth muscle actin, NLRP3, tumor necrosis factor-α, and interleukin-6. Mechanically, miR-135a-5p inhibited TXNIP expression to block the binding of TXNIP and NLRP3. On the other hand, TXNIP up-regulation reversed the protective role of miR-135a-5p over-expression in CFs. Collectively, our findings indicated that miR-135a-5p over-expression inhibited TXNIP expression to block the binding of TXNIP and NLRP3, thereby alleviating hypertensive cardiac inflammation and fibrosis.

Silencing of specificity protein 1 protects H9c2 cells against lipopolysaccharide-induced injury via binding to the promoter of chemokine CXC receptor 4 and suppressing NF-κB signaling

G protein-coupled protein receptor CXC chemokine receptor 4 (CXCR4) has been shown to be involved in the development of sepsis; however, it remains unclear whether CXCR4 participates in the septic myocardial injury. In our study, treatment with lipopolysaccharide (LPS) increased the expression of specificity protein 1 (SP1) and CXCR4 in H9c2 cells. Notably, a positive association between SP1 and CXCR4 expression was observed in LPS-treated H9c2 cells, and SP1 positively regulated CXCR4 expression in H9c2 cells. Moreover, silencing of SP1 or CXCR4 suppressed LPS-induced inflammation and cell apoptosis in H9c2 cells, as evidenced by the increase in cell viability and decrease in lactate dehydrogenase release, interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α levels, and caspase-3 activity. Additionally, overexpression of CXCR4 abolished the protective effects of SP1 silencing on LPS-induced injury in H9c2 cells. SP1 was also shown to enhance the promoter activity of CXCR4 by directly binding with the binding motif site – 109/–100 in CXCR4 promoter. Besides, downregulation of SP1 or CXCR4 blocked LPS-induced activation of the NF-кB signaling in H9c2 cells. Furthermore, inhibition of NF-кB signaling by DHMEQ abolished LPS-induced myocardial inflammation and apoptosis. In conclusion, silencing of SP1 protected H9c2 cells against LPS-induced injury by binding to the promoter of CXCR4 and suppressing the NF-κB signaling pathway. Hence, our findings provide evidence that manipulation of SP1 or CXCR4 may be an effective approach to promote prevention or recovery of septic myocardial injury, and thereby, may serve as a potential therapeutic strategy for sepsis.