MicroRNA-181a-5p alleviates acute liver failure in mice by inhibiting HMGB1.

MicroRNAs (miRNAs) control liver diseases, but the role of microRNA-181a-5p in acute liver failure (ALF) is unclear. In this study, the ALF model was generated by injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS). The levels of miRNAs were assessed by microarray and qRT-PCR. The expression of caspase 3 was detected as the marker of cell apoptosis in ALF by immunohistochemistry and western blot. The targeting of microRNA-181a-5p on the high mobility group box 1 (HMGB1) was verified by dual luciferase assay. The impact of microRNA-181a-5p and HMGB1 was explored by flow cytometry. Results showed that microRNA-181a-5p was significantly down-regulated by D-GalN/LPS in vivo and in vitro, while the level of HMGB1 was up-regulated after the challenge. Furthermore, microRNA-181a-5p overexpression attenuated cell apoptosis in D-GalN/TNF-treated BNLCL2 cells. MicroRNA-181a-5p could directly target HMGB1 mRNA and repress its expressions, in further HMGB1 is involved in microRNA-181a-5p effect on cell apoptosis of ALF. In conclusion, these findings demonstrate that microRNA-181a-5p regulates hepatocyte apoptosis via HMGB1 in the development of ALF, which may provide potential therapeutic targets for ALF. However, the precise underlying mechanism that connects microRNA-181a-5p and HMGB1 remains to be explored.

Possible mechanism by which renal sympathetic denervation improves left ventricular remodelling after myocardial infarction.

NEW FINDINGS: What is the central question of this study? The enzyme system that is responsible for extracellular matrix (ECM) turnover is the matrix metalloproteinases (MMPs), which can be blocked by the tissue inhibitors of MMPs (TIMPs). Whether renal sympathetic denervation (RSD) is able to ameliorate post-myocardial infarction left ventricular remodelling through attenuation of ECM via regulation of MMP activity and/or the MMP-TIMP complex remains unknown. What is the main finding and its importance? Renal sympathetic denervation has therapeutic effects on post-myocardial infarction left ventricular remodelling, probably by attenuating the ECM through regulation of the MMP9-TIMP1 complex in the transforming growth factor-ß1 (a profibrotic cytokine that accelerates ECM remodelling after ischaemia) signalling pathway. Whether renal sympathetic denervation (RSD) is able to ameliorate post-myocardial infarction (post-MI) left ventricular (LV) remodelling by attenuation of the extracellular matrix via regulation of matrix metalloproteinase (MMP) activity and/or the MMP-tissue inhibitor of matrix metalloproteinase (TIMP) complex remains unknown. Sixty-five Sprague-Dawley rats were randomly divided into the following four groups: normal (N, n = 15), RSD (RSD, n = 15), myocardial infarction (MI, n = 15) and RSD 3 days after MI (MI3d+RSD, n = 20). The bilateral renal nerves were surgically denervated 3 days after MI had been induced by coronary artery ligation. Left ventricular function was assessed using echocardiography and a Millar catheter at 6 weeks post-MI. Plasma noradrenaline, angiotensin II and aldosterone, collagen volume fraction, transforming growth factor-ß1 (TGF-ß1), MMP2, MMP9 and TIMP1 in heart tissue were measured 6 weeks after MI. In rats with MI3d+RSD compared with MI rats, RSD improved systolic and diastolic function, resulting in an improvement in ejection fraction (P < 0.05), fractional shortening (P < 0.05) and LV internal dimension in systole (P < 0.05) and diastole (P < 0.05). Additionally, RSD treatment decreased left ventricular end-diastolic pressure (P < 0.05) and increased LV systolic pressure (P < 0.05) and maximal and minimal rate of LV pressure (both P < 0.05). Meanwhile, RSD reduced collagen content (P < 0.01). TIMP1 was upregulated (P < 0.05), whereas MMP2, MMP9 and TGF-ß1 were downregulated in the LV of RSD-treated animals (P < 0.05). Renal sympathetic denervation has therapeutic effects on post-MI LV remodelling, probably owing to effects on the extracellular matrix by regulation of the MMP9-TIMP1 balance in the TGF-ß1 signalling pathway. Renal sympathetic denervation may be considered as a non-pharmacological approach for the improvement of post-MI cardiac dysfunction.

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction.

Vascular endothelial growth factor (VEGF), an independent mitogen, has been reported to induce angiogenesis and thus attenuates the damage induced by myocardial infarction (MI). VEGF165 is the most abundant and predominant isoform of VEGF. This study investigates whether this effect could be strengthened by local intramyocardial injection of VEGF165 along with a novel biodegradable Dex-PCL-HEMA/PNIPAAm hydrogel and ascertains its possible mechanism of action. Rat models of myocardial infarction were induced by coronary artery ligation. Phosphate-buffered saline (PBS group), Dex-PCL-HEMA/PNIPAAm hydrogel (Gel group), phosphate-buffered saline containing VEGF165 (VP group), and hydrogel containing VEGF165 (VPG group) were injected into a peri-infarcted area of cardiac tissue immediately after myocardial infarction, respectively. The sham group was thoracic but without myocardial infarction. The injection of VEGF165 along with a hydrogel induced angiogenesis, reduced collagen content and MI area, inhibited cell apoptosis, increased the level of VEGF165 protein and the expression of flk-1 and flt-1, and improved cardiac function compared with the injection of either alone after MI in rats. The results suggest that injection of VEGF165 along with a hydrogel acquires more cardioprotective effects than either alone in rat with MI by sustained release of VEGF165, then may enhance the feedback between VEGF and its receptors flk-1 and flt-1.

Renal Sympathetic Denervation in Rats Ameliorates Cardiac Dysfunction and Fibrosis Post-Myocardial Infarction Involving MicroRNAs.

BACKGROUND The role of renal sympathetic denervation (RSD) in ameliorating post-myocardial infarction (MI) left ventricular (LV) fibrosis via microRNA-dependent regulation of connective tissue growth factor (CTGF) remains unknown. MATERIAL AND METHODS MI and RSD were induced in Sprague-Dawley rats by ligating the left coronary artery and denervating the bilateral renal nerves, respectively. Norepinephrine, renin, angiotensin II and aldosterone in plasma, collagen, microRNA21, microRNA 101a, microRNA 133a and CTGF in heart tissue, as well as cardiac function were evaluated six weeks post-MI. RESULTS In the RSD group, parameters of cardiac function were significantly improved as evidenced by increased LV ejection fraction (p<0.01), LV end-systolic diameter (p<0.01), end-diastolic diameter (p<0.05), LV systolic pressure (p<0.05), maximal rate of pressure rise and decline (dP/dtmax and dP/dtmin, p<0.05), and decreased LV end-diastolic pressure (p<0.05) when compared with MI rats. Further, reduced collagen deposition in peri-infarct myocardium was observed in RSD-treated rats along with higher microRNA101a and microRNA133a (p<0.05) and lower microRNA21 expression (p<0.01) than in MI rats. CTGF mRNA and protein levels were decreased in LV following RSD (p<0.01), accompanied by decreased expression of norepinephrine, renin, angiotensin II and aldosterone in plasma (p<0.05) compared with untreated MI rats. CONCLUSIONS The potential therapeutic effects of RSD on post-MI LV fibrosis may be partly mediated by inhibition of CTGF expression via upregulation of microRNA 101a and microRNA 133a and downregulation of microRNA21.

Application of Fenton chemistry in electrochemical determination of pyrophosphatase activity and fluoride.

Fenton chemistry has aroused widespread concern due to its application in the green oxidation and mineralization of organic wastes. Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of pyrophosphate ions (PPi) and provides a thermodynamic driving force for many biosynthetic reactions. Fluoride (F-) is widely applied to fight against tooth decay and reduce cavities. The electrochemical determination of PPase activity and F- was realized based on Fenton chemistry in this work. Glassy carbon electrode modified with poly (azure A) and acetylene black (GCE/PAA-AB) was fabricated. Hydroxyl radicals (∙OH) that were generated from a Cu2+-catalyzed Fenton-type reaction could oxidize PAA in the near-neutral medium, leading to a great increase of the cathodic peak current (Ipc). A coordination reaction between PPi and Cu2+ exerted a negative effect on Fenton reaction and hindered the Ipc enhancement. Cu2+-PPi complex was decomposed due to the hydrolysis of PPi induced by PPase, which caused the reappearance of the notably increased current response. F- could effectively inhibit PPase activity. As a result, the stable Cu2+-PPi complex remained and the high Ipc suffered from the decline again. The Ipc difference was used for the highly sensitive determination of PPase activity in the content range of 0.001-20 mU mL-1 with a detection of limit (LOD) at 0.6 µU mL-1 and that of F- in the concentration range of 0.01-100 µM with a LOD at 7 nM. The proposed PPase and F- sensor displayed a good selectivity, stability and reproducibility, and a high accuracy.

Dihydroquercetin improves experimental acute liver failure by targeting ferroptosis and mitochondria-mediated apoptosis through the SIRT1/p53 axis.

BACKGROUND: Ferroptosis and mitochondria-mediated apoptosis are both involved in the pathogenesis of acute liver failure (ALF). Ferroptosis-produced reactive oxygen species (ROS) trigger the chain oxidation of polyunsaturated phospholipids and promote mitochondrial apoptosis. Dihydroquercetin (DHQ) also plays an important protective role against liver injury. PURPOSE: Here, we aimed to investigate the protective effects of DHQ on ALF. We also explored the underlying mechanism. METHODS: We established a Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced ALF mouse model and tumor necrosis factor-α (TNF-α)/D-Gal-induced ALF LO2 cell model. 2',7'-Dichlorofluorescein diacetate (DCFH-DA) and Dihydroethidium (DHE) were used to detect total ROS levels. Lipid ROS was assessed using C11-BODIPY flow cytometry. Lipid peroxidative products levels were detected using MDA ELISA assay and 4-hydroxynonenal (4-HNE) immunohistochemistry. QRT-PCR and western blots were used to test mRNA and protein expression levels, respectively. Cell viability was evaluated with CCK8 assay, and apoptosis was analyzed using flow cytometry. RESULTS: DHQ treatment improved LPS/D-Gal-induced ALF, as well as TNF-α/D-Gal-induced reductions in LO2 viability and increased sirtuin 1 (SIRT1) expression. DHQ pretreatment also reduced the accumulation of ROS, reduced lipid peroxidation, elevated mitochondrial membrane potentials (ΔΨm), and decreased liver cell apoptosis both in vivo and in vitro. Additionally, the knockdown of SIRT1 and p53 activator (Tenovin-6) treatment reversed DHQ's inhibitory effects on ferroptosis and mitochondria-mediated apoptosis in vitro. DHQ enhanced p53 deacetylation by both up-regulating SIRT1 expression and directly bonding to SIRT1. We also found that Tenovin-6's stimulatory effects on ferroptosis and mitochondria-mediated apoptosis in the DHQ-treated LO2 ALF cell model were partially attenuated by overexpression of solute carrier family 7member 11 (SLC7A11), as well as by apoptotic protease activating factor 1 (Apaf-1) knockdown. CONCLUSION: Our results suggest that DHQ alleviated ALF by inhibiting both ferroptosis and mitochondria-mediated apoptosis by regulating the SIRT1/p53 axis. Thus, DHQ may serve as a novel therapy for ALF.

Exogenous high-mobility group box 1 protein prevents postinfarction adverse myocardial remodeling through TGF-ß/Smad signaling pathway.

High-mobility group box 1 (HMGB1) has been reported to attenuate ventricular remodeling, but its mechanism remains mostly unresolved. Transforming growth factor-beta (TGF-ß) is a crucial mediator in the pathogenesis of post-infarction remodeling. Our study focused on the effects of HMGB1 on ventricular remodeling, and explored whether or not these effects were depended upon the TGF-ß signaling pathway. Rats underwent coronary artery ligation. An intramyocardium injection of phosphate buffered saline (PBS) with or without HMGB1 was administered 3 weeks after myocardial infarction (MI). At 4 weeks after the treatment, HMGB1 significantly increased the left ventricular ejection fraction (LVEF) (P < 0.05), decreased the left ventricular end diastolic dimension (LVEDD; P < 0.05), left ventricular end systolic dimension (LVESD) (P < 0.05) and the infarct size (P < 0.05) compared with control group. The expressions of collagen I, collagen III, and tissue inhibitor of metalloproteinase 2 (TIMP2) were also decreased, while the matrix metalloproteinases 2 (MMP2) and MMP9 expressions were upregulated by HMGB1 injection (P < 0.05) compared with control group. No effect on TIMP3 was observed. Furthermore, TGF-ß1 and phosphor-Smad2 (p-Smad2) were significantly suppressed and Smad7 was increased in HMGB1-treated group (P < 0.05) compared with control group, no effects on p-Smad3 and p-p38 were observed. HMGB1 also upregulated Smad 7 expression and decreased the level of collagen I on cardiac fibroblasts (P < 0.05). Silencing of Smad7 gene by small interfering RNA abolished the fibrogenic effects of HMGB1 on cardiac fibroblasts (P < 0.05). These finding suggested that HMGB1 injection modulated ventricular remodeling may function through the possible inhibition of TGF-ß/Smad signaling pathway.

Intramyocardial delivery of HMGB1 by a novel thermosensitive hydrogel attenuates cardiac remodeling and improves cardiac function after myocardial infarction.

BACKGROUND: High-mobility group box 1 (HMGB1), a nuclear protein, has been recently reported to attenuate cardiac remodeling after myocardial infarction (MI). This study was designed to investigate whether this effect could be strengthened by local intramyocardial injection of HMGB1 along with a novel Dex-PCL-HEMA/PNIPAAm hydrogel and ascertain its possible mechanism of action. METHODS: Rat models were induced by coronary artery ligation. Phosphate-buffered solution, Dex-PCL-HEMA/PNIPAAm hydrogel, HMGB1 in phosphate-buffered solution, or HMGB1 in hydrogel was injected into a peri-infarcted area of cardiac tissue immediately after MI. RESULTS: The injection of HMGB1 along with hydrogel improved cardiac function and reduced collagen content. Additionally, the number of c-Kit/Ki67, α-sarcomeric/MEF2C, and α-sarcomeric/Ki67 cells were increased significantly compared with the results of using either agent alone. CONCLUSIONS: HMGB1 injection with Dex-PCL-HEMA/PNIPAAm hydrogel attenuates cardiac remodeling and improves cardiac function after MI by inducing myocardial regeneration.

Changing trends of disease burden of stroke from 1990 to 2019 and its predictions among the Chinese population.

Objective: This study aimed to understand the temporal trends in the disease burden of stroke and its attributable risk factors in China, along with the future trends in the next 25 years, that is important for effective prevention strategies and improvement, and to provide new insights into the age- and sex-specific incidence, prevalence, mortality, disability-adjusted life-years (DALYs) and their trends from 1990 to 2019, and the prediction in the next 25 years. Methods: The Global Burden of Disease Study (2019) was used to extract the data on age- and sex-specific incidence, mortality, and disability-adjusted life-years (DALYs) of stroke in China, 1990-2019. We estimated the estimated annual percentage change (EAPC) to access the temporal trends of the disease burden of stroke. The R package called Nordpred was used to perform an age-period-cohort analysis to predict the prevalence of stroke. Results: The number of incidence cases, deaths, and DALYs of stroke increased from 1990 to 2019. Overall downward trends were observed in the age-standardized incidence rate (ASIR) from 1990 to 2019. Significant temporal trends in mortality and DALYs of stroke were observed. High systolic blood pressure, smoking, and high-sodium diet were the main driving forces for stroke. The DALYs lost attributable to smoking were different for male and female patients. In the next 25 years, the number of new cases and deaths from stroke should continue to increase. The ASIR and age-standardized mortality rate (ASMR) should show a downward trend among male and female patients. Conclusion: Despite the overall rates of stroke declined over the period from 1990 to 2019, the absolute number of people affected by stroke has substantially increased. There has been a substantial increase in the burden of stroke due to risk factors and will continue to increase in the next 25 years.

Key factors leading to fatal outcomes in COVID-19 patients with cardiac injury.

Cardiac injury among patients with COVID-19 has been reported and is associated with a high risk of mortality, but cardiac injury may not be the leading factor related to death. The factors related to poor prognosis among COVID-19 patients with myocardial injury are still unclear. This study aimed to explore the potential key factors leading to in-hospital death among COVID-19 patients with cardiac injury. This retrospective single-center study was conducted at Renmin Hospital of Wuhan University, from January 20, 2020 to April 10, 2020, in Wuhan, China. All inpatients with confirmed COVID-19 (≥ 18 years old) and cardiac injury who had died or were discharged by April 10, 2020 were included. Demographic data and clinical and laboratory findings were collected and compared between survivors and nonsurvivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with mortality in COVID-19 patients with cardiac injury. A total of 173 COVID-19 patients with cardiac injury were included in this study, 86 were discharged and 87 died in the hospital. Multivariable regression showed increased odds of in-hospital death were associated with advanced age (odds ratio 1.12, 95% CI 1.05-1.18, per year increase; p < 0.001), coagulopathy (2.54, 1.26-5.12; p = 0·009), acute respiratory distress syndrome (16.56, 6.66-41.2; p < 0.001), and elevated hypersensitive troponin I (4.54, 1.79-11.48; p = 0.001). A high risk of in-hospital death was observed among COVID-19 patients with cardiac injury in this study. The factors related to death include advanced age, coagulopathy, acute respiratory distress syndrome and elevated levels of hypersensitive troponin I.

Exosomal lncRNA HOTTIP Mediates Antiviral Effect of Tenofovir Alafenamide (TAF) on HBV Infection.

INTRODUCTION: Chronic hepatitis B (CHB) virus (HBV) infection has emerged as a global health burden affecting nearly 292 million people. Tenofovir alafenamide (TAF) is an effective treatment for CHB patients. However, the detailed mechanism underlying the antiviral activity of TAF remains unclear. METHODS: In this study, we investigated the antiviral effect of exosomes derived from the serum of CHB patients treated with TAF (Exo-serum) and TAF-treated macrophages (MP) (Exo-MP(TAF)). RESULTS: RNAseq analysis was also performed to determine the associated long non-coding RNAs (lncRNAs). The results demonstrated that both Exo-serum and Exo-MP(TAF) could be taken up by HepAD38 cells and exhibited potent antiviral activities, as manifested by significantly downregulating the levels of hepatitis B surface antigen, hepatitis B e antigen, HBV DNA, and covalently closed circular DNA. The antiviral effect of Exo-serum was more potent than those of TAF treatment alone. RNAseq analysis revealed that lncRNA HOTTIP was upregulated significantly in Exo-serum. Further, lncRNA HOTTIP knockdown reversed the antiviral effect of Exo-MP(TAF) on HepAD38 cells, whereas lncRNA HOTTIP knockdown exerted the opposite roles. DISCUSSION: Taken together, these results suggest that exosomal lncRNA HOTTIP is essential for the antiviral activity of TAF and provide a novel understanding of the exosome-mediated mechanism underlying HBV infection.

Effects of hesperetin on platelet-derived growth factor-BB-induced pulmonary artery smooth muscle cell proliferation.

Hesperetin is a natural flavonoid, which has been reported to exert various biological activities and positive health effects on mammalian cells. The present study aimed to investigate the effects of hesperetin on the proliferation of primary cultured rat pulmonary artery smooth muscle cells (PASMCs), and to elucidate the possible underlying molecular mechanisms. The results of the present study indicated that hesperetin was able to inhibit the proliferation and DNA synthesis of platelet­derived growth factor­BB (PDGF­BB)­induced PASMCs in a dose­ and time­dependent manner, without exerting cell cytotoxicity. In addition, hesperetin blocked the progression of the cell cycle from G0/G1 to S phase, which was correlated with the decreased mRNA expression levels of cyclin D1, cyclin E, cyclin­dependent kinase (CDK)2 and CDK4, and the increased mRNA expression levels of p27. Furthermore, the anti­proliferative effects of hesperetin were associated with suppression of the AKT/glycogen synthase kinase (GSK)3ß and p38 signaling pathway, but were not associated with the extracellular signal­regulated kinases 1/2 and c­Jun N­terminal kinases signaling pathways. These results suggested that hesperetin may inhibit PDGFa­BB­induced PASMC proliferation via the AKT/GSK3ß signaling pathway, and that it may possess therapeutic potential for the treatment of pulmonary vascular remodeling diseases.

A novel, biodegradable, thermoresponsive hydrogel attenuates ventricular remodeling and improves cardiac function following myocardial infarction - a review.

Myocardial infarction (MI) and the subsequent heart failure remain among of the leading causes of morbidity and mortality in world wide. A number of studies have demonstrated that intramyocardial biomaterials injections improve cardiac function after implantation because of their angiogenic potential. Thermoresponsive hydrogels, one member of the hydrogels family, are a kind of biomaterial whose structure is similar to that of extracellular matrix. These hydrogels have been interesting for biomedical uses as they can swell in situ under physiological conditions and provide the advantage of convenient administration. The hydrogel that our team is interested in is a novel biodegradable injectable thermoresponsive hydrogel-the copolymer dextran-poly (ε-caprolactone) -2-hydroxylethyl methacrylatepoly (N-isopropylacrylaminde) (Dex-PCL-HEMA/PNIPAAm). Thus, this review will focus on requirements and challenges of injectable synthetic material, and possible mechanism of thermoresponsive hydrogel in treating MI. The main emphases are on the work done and future interesting studies in our laboratory.