The thiazolidinedione (TZD) class of Peroxisome proliferator-activated receptor gamma agonists has restricted clinical use for diabetes mellitus due to fluid retention and potential cardiovascular risks. These side effects are attributed in part to direct salt-retaining effect of TZDs at the renal collecting duct. A recent study from our group revealed that prolonged rosiglitazone (RGZ) treatment caused no Na+/H2 O retention or up-regulation of Na+ transport-linked channels/transporters in experimental congestive heart failure (CHF) induced by surgical aorto-caval fistula (ACF). The present study examines the effects of RGZ on renal and cardiac responses to atrial natriuretic peptide (ANP), Acetylcholine (Ach) and S-Nitroso-N-acetylpenicillamine (SNAP-NO donor). Furthermore, we assessed the impact of RGZ on gene expression related to the ANP signalling pathway in animals with ACF. Rats subjected to ACF (or sham) were treated with either RGZ (30 mg/kg/day) or vehicle for 4 weeks. Cardiac chambers pressures and volumes were assessed invasively via Miller catheter. Kidney excretory and renal hemodynamic in response to ANP, Ach and SNAP were examined. Renal clearance along with cyclic guanosine monophosphate (cGMP), gene expression of renal CHF-related genes and ANP signalling in the kidney were determined. RGZ-treated CHF rats exhibited significant improvement in the natriuretic responses to ANP infusion. This 'sensitization' to ANP was not associated with increases in neither urinary cGMP nor in vitro cGMP production. However, RGZ caused down-regulation of several genes in the renal cortex (Ace, Nos3 and Npr1) and up-regulation of ACE2, Agtrla, Mme and Cftr along down-regulation of Avpr2, Npr1,2, Nos3 and Pde3 in the medulla. In conclusion, CHF+RGZ rats exhibited significant enhancement in the natriuretic responses to ANP infusion, which are known to be blunted in CHF. This 'sensitization' to ANP is independent of cGMP signalling, yet may involve post-cGMP signalling target genes such as ACE2, CFTR and V2 receptor. The possibility that TZD treatment in uncomplicated CHF may be less detrimental than thought before deserves additional investigations.

Tissue inhibitor of matrix metalloprotease 4 (TIMP4) is endogenously one of the key modulators of matrix metalloprotease 9 (MMP9) and we have reported earlier that cardiac specific TIMP4 instigates contractility and helps in differentiation of cardiac progenitor cells. Although studies show that the expression of TIMP4 goes down in heart failure but the mechanism is unknown. This study aims to determine the mechanism of silencing of TIMP4 in heart failure progression created by aorta-vena cava (AV) fistula. We hypothesize that there is epigenetic silencing of TIMP4 in heart failure. To validate this hypothesis, we created heart failure model by creating AV fistula in C57BL/6 mice and looked into the promoter methylation (methylation specific PCR, high resolution melting, methylation sensitive restriction enzyme and Na bisulphite treatment followed by sequencing), histone modification (ChIP assay) and microRNAs that regulate TIMP4 (mir122a) and MMP9 (mir29b and mir455-5p). The physiological parameters in terms of cardiac function after AV fistula were assessed by echocardiography. We observed that there are 7 CpG islands in the TIMP4 promoter which get methylated during the progression of heart failure which leads to its epigenetic silencing. In addition, the up-regulated levels of mir122a in part, contribute to regulation of TIMP4. Consequently, MMP9 gets up-regulated and leads to cardiac remodeling. This is a novel report to explain the epigenetic silencing of TIMP4 in heart failure.

Epicardial adipose tissue (EAT) is a metabolically active visceral fat depot closely linked to the pathogenesis of heart failure (HF). But the molecular signatures related to the mechanism of HF have not been systematically explored. Here, we present comprehensive proteomic analysis of EAT in HF patients and non-HF patients as controls. A total of 771 proteins were identified in liquid chromatography-tandem mass spectrometry experiments. Amongst them, 17 increased in abundance in HF and seven decreased. They were involved in HF-related processes including inflammation and oxidative stress response and lipid metabolism. Of these proteins, serine proteinase inhibitor A3 (Serpina3) levels in EAT were highly up-regulated in HF, with HF/non-HF ratio of 4.63 (P = .0047). Gene expression of Serpina3 via quantitative polymerase chain reaction was significantly increased in the HF group. ELISA analysis confirmed a significant increase in circulating plasma Serpina3 levels in the HF group (P = .004). In summary, for the first time, we describe that parts of EAT proteome may be reactive and work as modulators of HF. Our profiling provides a comprehensive basis for linking EAT with pathogenesis of HF. Understanding the role of EAT may offer new insights into the treatment of HF.

Acute liver failure (ALF) is associated with high mortality, and a poor understanding of the underlying pathophysiology has resulted in a lack of effective treatments so far. Here, using an amatoxin-induced rhesus monkey model of ALF, we panoramically revealed the cellular and molecular events that lead to the development of ALF. The challenged monkeys with toxins underwent a typical course of ALF including severe hepatic injury, systemic inflammation and eventual death. Adaptive immune was not noticeably disturbed throughout the progress of ALF. A systematic examination of serum factors and cytokines revealed that IL-6 increase was the most rapid and drastic. Interestingly, we found that IL-6 was mainly produced by circulating monocytes. Furthermore, ablation of monocyte-derived IL-6 in mice decreased liver injury and systemic inflammation following chemical injection. Our findings reveal a critical role of circulating monocytes in initiating and accelerating ALF, indicating a potential therapeutic target in clinical treatment for ALF.

This study tested the reversal of subcellular remodelling in heart failure due to myocardial infarction (MI) upon treatment with losartan, an angiotensin II receptor antagonist. Twelve weeks after inducing MI, rats were treated with or without losartan (20 mg/kg; daily) for 8 weeks and assessed for cardiac function, cardiac remodelling, subcellular alterations and plasma catecholamines. Cardiac hypertrophy and lung congestion in 20 weeks MI-induced heart failure were associated with increases in plasma catecholamine levels. Haemodynamic examination revealed depressed cardiac function, whereas echocardiographic analysis showed impaired cardiac performance and marked increases in left ventricle wall thickness and chamber dilatation at 20 weeks of inducing MI. These changes in cardiac function, cardiac remodelling and plasma dopamine levels in heart failure were partially or fully reversed by losartan. Sarcoplasmic reticular (SR) Ca(2+)-pump activity and protein expression, protein and gene expression for phospholamban, as well as myofibrillar (MF) Ca(2+)-stimulated ATPase activity and α-myosin heavy chain mRNA levels were depressed, whereas β-myosin heavy chain expression was increased in failing hearts; these alterations were partially reversed by losartan. Although SR Ca(2+)-release activity and mRNA levels for SR Ca(2+)-pump were decreased in failing heart, these changes were not reversed upon losartan treatment; no changes in mRNA levels for SR Ca(2+)-release channels were observed in untreated or treated heart failure. These results suggest that the partial improvement of cardiac performance in heart failure due to MI by losartan treatment is associated with partial reversal of cardiac remodelling as well as partial recovery of SR and MF functions.

Acute liver failure (ALF) is a rare disease characterized by the sudden onset of serious hepatic injury, as manifested by a profound liver dysfunction and hepatic encephalopathy in patients without prior liver disease. In this paper, we aim to investigate whether verapamil, an antagonist of TXNIP, inhibits early ALF through suppressing the NLRP3 inflammasome pathway. Firstly, an ALF mouse model was induced by lipopolysaccharide (LPS)/D-galactosamine (GalN) treatment. The optimal concentration of verapamil in treating early ALF mice was determined followed by investigation on its mechanism in LPS/GalN-induced liver injury. Western blot analysis and co-immunoprecipitation were performed to determine the activation of the TXNIP/NLRP3 inflammasome pathway. Subsequently, overexpression of NLRP3 in mouse liver was induced by transfection with AAV-NRLP3 in vivo and in vitro to identity whether verapamil inhibited early ALF through suppressing the activation of NLRP3 inflammasome. We found that ALF was induced by LPS/GalN in mice but was alleviated by verapamil through a mechanism that correlated with suppression of the NLRP3 inflammasome pathway. Oxidative stress and inflammatory response were induced by intraperitoneal injection of LPS/GalN, but alleviated with injection of verapamil. Overexpression of NLRP3 via AAV in mouse liver in vivo and in vitro reduced the therapeutic effect of verapamil on LPS/GalN-induced ALF. Taken together, the TXNIP antagonist verapamil could inhibit activation of the NLRP3 inflammasome, inflammatory responses and oxidative stress to alleviate LPS/GalN-induced ALF.

Shock wave treatment (SWT) was shown to induce regeneration of ischaemic myocardium via Toll-like receptor 3 (TLR3). The antimicrobial peptide LL37 gets released by mechanical stress and is known to form complexes with nucleic acids thus activating Toll-like receptors. We suggested that SWT in the acute setting prevents from the development of heart failure via RNA/protein release. Myocardial infarction in mice was induced followed by subsequent SWT. Heart function was assessed 4 weeks later via transthoracic echocardiography and pressure-volume measurements. Human umbilical vein endothelial cells (HUVECs) were treated with SWT in the presence of RNase and proteinase and analysed for proliferation, tube formation and LL37 expression. RNA release and uptake after SWT was evaluated. We found significantly improved cardiac function after SWT. SWT resulted in significantly higher numbers of capillaries and arterioles and less left ventricular fibrosis. Supernatants of treated cells activated TLR3 reporter cells. Analysis of the supernatant revealed increased RNA levels. The effect could not be abolished by pre-treatment of the supernatant with RNase, but only by a sequential digestion with proteinase and RNase hinting strongly towards the involvement of RNA/protein complexes. Indeed, LL37 expression as well as cellular RNA uptake were significantly increased after SWT. We show for the first time that SWT prevents from left ventricular remodelling and cardiac dysfunction via RNA/protein complex release and subsequent induction of angiogenesis. It might therefore develop a potent regenerative treatment alternative for ischaemic heart disease.

Although β-adrenoceptor (β-AR) blockade is an important mode of therapy for congestive heart failure (CHF), subcellular mechanisms associated with its beneficial effects are not clear. Three weeks after inducing myocardial infarction (MI), rats were treated daily with or without 20 and 75 mg/kg atenolol, a selective β(1) -AR antagonist, or propranolol, a non-selective β-AR antagonist, for 5 weeks. Sham operated rats served as controls. All animals were assessed haemodynamically and echocardiographically and the left ventricle (LV) was processed for the determination of myofibrillar ATPase activity, α- and β-myosin heavy chain (MHC) isoforms and gene expression as well as cardiac troponin I (cTnI) phosphorylation. Both atenolol and propranolol at 20 and 75 mg/kg doses attenuated cardiac hypertrophy and lung congestion in addition to increasing LV ejection fraction and LV systolic pressure as well as decreasing heart rate, LV end-diastolic pressure and LV diameters in the infarcted animals. Treatment of infarcted animals with these agents also attenuated the MI-induced depression in myofibrillar Ca(2+) -stimulated ATPase activity and phosphorylated cTnI protein content. The MI-induced decrease in α-MHC and increase in β-MHC protein content were attenuated by both atenolol and propranolol at low and high doses; however, only high dose of propranolol was effective in mitigating changes in the gene expression for α-MHC and β-MHC. Our results suggest that improvement of cardiac function by β-AR blockade in CHF may be associated with attenuation of myofibrillar remodelling.

Stem cell exosomes are nanoscale membrane vesicles released from stem cells of various origins that can regulate signal transduction pathways between liver cells, and their functions in intercellular communication have been recognized. Due to their natural substance transport properties and excellent biocompatibility, exosomes can also be used as drug carriers to release a variety of substances, which has great prospects in the treatment of critical and incurable diseases. Different types of stem cell exosomes have been used to study liver diseases. Due to current difficulties in the treatment of acute liver failure (ALF), this review will outline the potential of stem cell exosomes for ALF treatment. Specifically, we reviewed the pathogenesis of acute liver failure and the latest progress in the use of stem cell exosomes in the treatment of ALF, including the role of exosomes in inhibiting the ALF inflammatory response and regulating signal transduction pathways, the advantages of stem cell exosomes and their use as a drug-loading system, and their pre-clinical application in the treatment of ALF. Finally, the clinical research status of stem cell therapy for ALF and the current challenges of exosome clinical transformation are summarized.

There are controversies concerning the capacity of Rosuvastatin to attenuate heart failure in end-stage hypertension. The aim of the study was to show whether the Rosuvastatin might be effective or not for the heart failure treatment. Twenty-one spontaneously hypertensive rats (SHRs) aged 52 weeks with heart failure were randomly divided into three groups: two receiving Rosuvastatin at 20 and 40 mg/kg/day, respectively, and the third, placebo for comparison with seven Wistar-Kyoto rats (WKYs) as controls. After an 8-week treatment, the systolic blood pressure (SBP) and echocardiographic features were evaluated; mRNA level of B-type natriuretic peptide (BNP) and plasma NT-proBNP concentration were measured; the heart tissues were observed under electron microscope (EM); myocardial sarcoplasmic reticulum Ca(2+) pump (SERCA-2) activity and mitochondria cytochrome C oxidase (CCO) activity were measured; the expressions of SERCA-2a, phospholamban (PLB), ryanodine receptor2 (RyR2), sodium-calcium exchanger 1 (NCX1), Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and protein phosphatase inhibitor-1 (PPI-1) were detected by Western blot and RT-qPCR; and the total and phosphorylation of protein kinase Cα/β (PKCα/β) were measured. Aged SHRs with heart failure was characterized by significantly decreased left ventricular ejection fraction and left ventricular fraction shortening, enhanced left ventricular end-diastolic diameter and LV Volume, accompanied by increased plasma NT-proBNP and elevated BNP gene expression. Damaged myofibrils, vacuolated mitochondria and swollen sarcoplasmic reticulum were observed by EM. Myocardium mitochondria CCO and SERCA-2 activity decreased. The expressions of PLB and NCX1 increased significantly with up-regulation of PPI-1 and down-regulation of CaMKII, whereas that of RyR2 decreased. Rosuvastatin was found to ameliorate the heart failure in aged SHRs and to improve changes in SERCA-2a, PLB, RyR2, NCX1, CaMKII and PPI-1; PKCα/β2 signal pathway to be suppressed; the protective effect of Rosuvastatin to be dose dependent. In conclusion, the heart failure of aged SHRs that was developed during the end stage of hypertension could be ameliorated by Rosuvastatin.

Protocatechuic acid (3,4-dihydroxybenzoic acid) prevents oxidative stress, inflammation and cardiac hypertrophy. This study aimed to investigate the therapeutic effects of protocatechuic acid in an isoproterenol-induced heart failure mouse model and to identify the underlying mechanisms. To establish the heart failure model, C57BL/6NTac mice were given high-dose isoproterenol (80 mg/kg body weight) for 14 days. Echocardiography revealed that protocatechuic acid reversed the isoproterenol-induced downregulation of fractional shortening and ejection fraction. Protocatechuic acid attenuated cardiac hypertrophy as evidenced by the decreased heart-weight-to-body-weight ratio and the expression of Nppb. RNA sequencing analysis identified kynurenine-3-monooxygenase (Kmo) as a potential target of protocatechuic acid. Protocatechuic acid treatment or transfection with short-interfering RNA against Kmo ameliorated transforming growth factor β1-induced upregulation of Kmo, Col1a1, Col1a2 and Fn1 in vivo or in neonatal rat cardiac fibroblasts. Kmo knockdown attenuated the isoproterenol-induced increase in cardiomyocyte size, as well as Nppb and Col1a1 expression in H9c2 cells or primary neonatal rat cardiomyocytes. Moreover, protocatechuic acid attenuated Kmo overexpression-induced increases in Nppb mRNA levels. Protocatechuic acid or Kmo knockdown decreased isoproterenol-induced ROS generation in vivo and in vitro. Thus, protocatechuic acid prevents heart failure by downregulating Kmo. Therefore, protocatechuic acid and Kmo constitute a potential novel therapeutic agent and target, respectively, against heart failure.

Chronic renal failure (CRF) is commonly associated with various adverse consequences including pathological vascular calcification (VC), which represents a significant clinical concern. Existing literature has suggested the involvement of histone deacetylases (HDACs) in the progression of CRF-induced VC. However, the underlying molecular mechanisms associated with HDACs remain largely unknown. Therefore, we established the adenine-induced CRF rat model and in vitro VC models based on vascular smooth muscle cells (VSMCs) to examine HDAC1/lysine demethylase 1A (LSD1)/SESN2 as a novel molecular pathway in CRF-induced VC. Our initial results demonstrated that HDAC1 reduced the formation of VC in vivo and in vitro. HDAC1 was found to deacetylate LSD1, which subsequently led to impaired transcriptional activity in CRF-induced VC. Moreover, our results illustrated that LSD1 diminished the enrichment of H3K4me2 at the SESN2 promoter. Autophagy was identified as a vasculo-protective element against calcification in VC. Finally, we found that the inhibitory effects of HDAC1 overexpression on VC were partially abolished via over-expressed LSD1 in adenine-induced CRF model rats and in high phosphate-induced VSMCs. Taken together, these results highlight the crucial role of HDAC1 as an antagonistic factor in the progression of VC in CRF, and also revealed a novel regulatory mechanism by which HDAC1 operates. These findings provide significant insight and a fresh perspective into promising novel treatment strategies by up-regulating HDAC1 in CRF.

Myocardial infarction (MI) commonly leads to cardiomyocyte apoptosis and heart failure. Mangiferin is a natural glucosylxanthone extracted from mango fruits and leaves, which has anti-apoptotic and anti-inflammatory properties in experimental cardiovascular diseases. In the present study, we investigated the role and detailed mechanism of mangiferin in MI. We used ligation of the left anterior descending coronary artery to establish an MI model in vivo, and cardiomyocyte-specific Sirt1 knockout mice were used to identify the mechanism of mangiferin. For in vitro studies, oxygen and glucose deprivation (OGD) was used to mimic ischaemia in H9c2 cardiomyocytes. In mice, mangiferin treatment increased Sirt1 expression after MI, significantly reduced the infarct area, and prevented MI-induced apoptosis and heart failure. Mangiferin reduced OGD-induced cellular apoptosis in H9c2 cells. Meanwhile, Sirt1 knockout/silencing abolished the protective effects of mangiferin. Further studies revealed that mangiferin increased FoxO3a deacetylation by up-regulating Sirt1, thus preventing apoptosis, and adenovirus-mediated constitutive acetylation of FoxO3a restricted the anti-apoptotic effects of mangiferin in vivo and in vitro. Our results indicate that mangiferin prevents cardiomyocyte apoptosis and the subsequent heart failure by activating the Sirt1/FoxO3a pathway in MI, and suggest that mangiferin may have an interesting potential in following studies towards clinical evaluation.

Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome with poor prognosis. Several studies have begun to prove that mitochondria play a crucial role in liver failure. Mitofusin2 (Mfn2) plays a key role in maintaining the integrity of mitochondrial morphology and function. However, the role and underlying mechanisms of Mfn2 on cell autophagy of ACLF remain unclear. Our aim was to explore the effect of Mfn2 on several biological functions involving cell autophagy in ACLF. In this study, we constructed an ACLF animal model and a hepatocyte autophagy model, using adenovirus and lentivirus to deliver Mfn2 to liver cells, in order to assess the effect of Mfn2 on autophagy and apoptosis in ACLF. Furthermore, we explored the biological mechanism of Mfn2-induced autophagy of ACLF using Western blotting, RT-PCR and electron microscopy. We found that Mfn2 significantly attenuated ACLF, characterized by ameliorated gross appearance and microscopic histopathology of liver, and reduced serum AST, ALT, and TBIL levels. Mfn2 improved the expressions of LC3-II, Atg5 and Bcl-2 and down-regulated the expression of P62 and Bax in ACLF. Like rapamycin, Mfn2 also significantly inhibited the expressions of p-PI3K, p-Akt and p-mTOR in ACLF. In conclusion, our findings suggest that Mfn2 influences multiple biological functions of ACLF via the PI3K/Akt/mTOR signalling pathway. This study will provide a reliable theoretical basis for the application of Mfn2 as an effective target for ACLF treatment, reversing or delaying the process of ACLF.

In our previous studies, we reported that myeloid differentiation protein 1 (MD1) serves as a negative regulator in several cardiovascular diseases. However, the role of MD1 in heart failure with preserved ejection fraction (HFpEF) and the underlying mechanisms of its action remain unclear. Eight-week-old MD1-knockout (MD1-KO) and wild-type (WT) mice served as models of HFpEF induced by uninephrectomy, continuous saline or d-aldosterone infusion and a 1.0% sodium chloride treatment in drinking water for 4 weeks to investigate the effect of MD1 on HFpEF in vivo. H9C2 cells were treated with aldosterone to evaluate the role of MD1 KO in vitro. MD1 expression was down-regulated in the HFpEF mice; HFpEF significantly increased the levels of intracellular reactive oxygen species (ROS) and promoted autophagy; and in the MD1-KO mice, the HFpEF-induced intracellular ROS and autophagy effects were significantly exacerbated. Moreover, MD1 loss activated the p38-MAPK pathway both in vivo and in vitro. Aldosterone-mediated cardiomyocyte autophagy was significantly inhibited in cells pre-treated with the ROS scavenger N-acetylcysteine (NAC) or p38 inhibitor SB203580. Furthermore, inhibition with the autophagy inhibitor 3-methyladenine (3-MA) offset the aggravating effect of aldosterone-induced autophagy in the MD1-KO mice and cells both in vivo and in vitro. Our results validate a critical role of MD1 in the pathogenesis of HFpEF. MD1 deletion exaggerates cardiomyocyte autophagy in HFpEF via the activation of the ROS-mediated MAPK signalling pathway.

Heart failure (HF) is characterized by asymmetrical autonomic balance. Treatments to restore parasympathetic activity in human heart failure trials have shown beneficial effects. However, mechanisms of parasympathetic-mediated improvement in cardiac function remain unclear. The present study examined the effects and underpinning mechanisms of chronic treatment with the cholinesterase inhibitor, pyridostigmine (PYR), in pressure overload HF induced by transverse aortic constriction (TAC) in mice. TAC mice exhibited characteristic adverse structural (left ventricular hypertrophy) and functional remodelling (reduced ejection fraction, altered myocyte calcium (Ca) handling, increased arrhythmogenesis) with enhanced predisposition to arrhythmogenic aberrant sarcoplasmic reticulum (SR) Ca release, cardiac ryanodine receptor (RyR2) hyper-phosphorylation and up-regulated store-operated Ca entry (SOCE). PYR treatment resulted in improved cardiac contractile performance and rhythmic activity relative to untreated TAC mice. Chronic PYR treatment inhibited altered intracellular Ca handling by alleviating aberrant Ca release and diminishing pathologically enhanced SOCE in TAC myocytes. At the molecular level, these PYR-induced changes in Ca handling were associated with reductions of pathologically enhanced phosphorylation of RyR2 serine-2814 and STIM1 expression in HF myocytes. These results suggest that chronic cholinergic augmentation alleviates HF via normalization of both canonical RyR2-mediated SR Ca release and non-canonical hypertrophic Ca signaling via STIM1-dependent SOCE.

Acute liver failure (ALF) is a rare and critical medical condition. This study was designed to investigate the protective effects and underlying mechanism of ACY1215 in ALF mice. Our findings suggested that ACY1215 treatment ameliorates the pathological hepatic damage of ALF and decreases the serum levels of ALT and AST. Furthermore, ACY1215 pretreatment increased the level of ATM, γ-H2AX, Chk2, p53, p21, F-actin and vinculin in ALF. Moreover, ACY1215 inhibited the level of NLRP3, ASC, caspase-1, IL-1β and IL-18 in ALF. The ATM inhibitor KU55933 could decrease the level of ATM, γ-H2AX, Chk2, p53, p21, F-actin and vinculin in ALF with ACY1215 pretreatment. The F-actin inhibitor cytochalasin B decreased the level of F-actin and vinculin in ALF with ACY1215 pretreatment. However, cytochalasin B had no effect on protein levels of ATM, Chk2, p53 and p21 in ALF with ACY1215 pretreatment. Cytochalasin B could dramatically increase the level of NLRP3, ASC, caspase-1, IL-1β and IL-18 in ALF with ACY1215 pretreatment. These results indicated that ACY1215 exhibited hepatoprotective properties, which was associated with the inhibition of NLRP3 inflammasome, and this effect of ACY1215 was connected with upregulation of the ATM/F-actin mediated signalling pathways.

Long noncoding RNA HOX transcript antisense RNA (HOTAIR) has been studied in multiple diseases, but the role of HOTAIR on chronic heart failure (CHF) through the regulation of microRNA (miR)-30a-5p and lysine-specific demethylase 3A (KDM3A) remains unexplored. This research aims to probe the effects of HOTAIR on CHF progression via modulating miR-30a-5p to target KDM3A. CHF mouse model was established by intraperitoneal injection of doxorubicin. The CHF mice were then injected with high-expressed HOTAIR, miR-30a-5p or KDM3A adenovirus vectors to determine the cardiac function, oxidative stress, inflammatory response, pathological change and cardiomyocyte apoptosis. HOTAIR, miR-30a-5p, KDM3A and Bcl-2/adenovirus E1B 19kDa interacting protein 3 (BNIP3) expression in CHF mice was detected. The binding relations among HOTAIR, miR-30a-5p and KDM3A were validated. HOTAIR and KDM3A were depleted, while miR-30a-5p was augmented in CHF mice. The elevated HOTAIR or KDM3A or could improve cardiac function, mitigate oxidative stress and pathological change, reduce inflammatory factor levels and cardiomyocyte apoptosis, while the increased miR-30a-5p exerted opposite effects. The miR-30a-5p elevation could reverse the effects of enriched HOTAIR, while BNIP3 reduction abrogated the effects of KDM3A on CHF. HOTAIR sponged miR-30a-5p that targeted KDM3A. HOTAIR improves cardiac injury in CHF via modulating miR-30a-5p to target KDM3A. This study provides novel therapeutic strategies for CHF treatment.

Zn2+ -homoeostasis including free Zn2+ ([Zn2+ ]i ) is regulated through Zn2+ -transporters and their comprehensive understanding may be important due to their contributions to cardiac dysfunction. Herein, we aimed to examine a possible role of Zn2+ -transporters in the development of heart failure (HF) via induction of ER stress. We first showed localizations of ZIP8, ZIP14 and ZnT8 to both sarcolemma and S(E)R in ventricular cardiomyocytes (H9c2 cells) using confocal together with calculated Pearson's coefficients. The expressions of ZIP14 and ZnT8 were significantly increased with decreased ZIP8 level in HF. Moreover, [Zn2+ ]i was significantly high in doxorubicin-treated H9c2 cells compared to their controls. We found elevated levels of ER stress markers, GRP78 and CHOP/Gadd153, confirming the existence of ER stress. Furthermore, we measured markedly increased total PKC and PKCα expression and PKCα-phosphorylation in HF. A PKC inhibition induced significant decrease in expressions of these ER stress markers compared to controls. Interestingly, direct increase in [Zn2+ ]i using zinc-ionophore induced significant increase in these markers. On the other hand, when we induced ER stress directly with tunicamycin, we could not observe any effect on expression levels of these Zn2+ transporters. Additionally, increased [Zn2+ ]i could induce marked activation of PKCα. Moreover, we observed marked decrease in [Zn2+ ]i under PKC inhibition in H9c2 cells. Overall, our present data suggest possible role of Zn2+ transporters on an intersection pathway with increased [Zn2+ ]i and PKCα activation and induction of HF, most probably via development of ER stress. Therefore, our present data provide novel information how a well-controlled [Zn2+ ]i via Zn2+ transporters and PKCα can be important therapeutic approach in prevention/treatment of HF.

Inflammatory cytokine-induced cell apoptosis is important for initiation and progression of chronic heart failure (CHF). Non-coding RNAs, including long non-coding RNAs and microRNAs, have emerged as critical regulators of this pathological process. The role in regulating inflammation and induction to cell apoptosis in CHF is not well understood. This study found CHF patients had elevated serum miR-939-5p, with greater increase in New York Heart Association (NYHA) I-II patients than in NYHA III-IV. Moreover, miR-939-5p was positively correlated with B-type natriuretic peptide (BNP) in NYHA III-IV patients, while not in NYHA I-II. Further study showed miR-939-5p mimics promoted cell proliferation and inhibited inflammatory cytokine-induced apoptosis of HUVECs and H9C2, while inhibition of endogenous miR-939-5p produced the opposite effects. Induced nitric oxide synthase (iNOS) and tumour necrosis factor α (TNFα) were identified as target genes of miR-939-5p. Additionally, lncRNA-NOS2P3 acted as an endogenous sponge RNA to inhibit miR-939-5p expression, regulate the expression of iNOS/TNFα and control inflammation-induced cells apoptosis. These suggest that CHF patients exhibited elevated serum miR-939-5p level especially in NYHA I-II grades. And lnc-NOS2P3-miR-939-5p-iNOS/TNFα pathway regulated inflammatory cytokine-induced endothelial and myocardial cells apoptosis and provided a promising strategy for diagnosis and treatment of CHF.