Hanping Qi

Activation of peroxisome proliferator-activated receptor γ (PPARγ) through NF-κB/Brg1 and TGF-β1 pathways attenuates cardiac remodeling in pressure-overloaded rat hearts.

Background/Aims: Cardiac remodeling is a common pathophysiological change along with chronic hypertension and myocardial infarction. Recent evidence indicated that cardiac tissue expressed peroxisome proliferator-activated receptor γ (PPARγ). However, the functional role of PPARγ in cardiac remodeling remained unclear. The present study was designed to investigate the relationship between PPARγ activation and pressure overload-induced cardiac remodeling. Methods: Cardiac remodeling model was successfully established by abdominal aorta ligation. Cardiac fibrosis and cardiomyocyte hypertrophy were simulated by 100 nM angiotensin II (Ang II) in vitro. Haemodynamic parameters, the expressions of Brg1, a-MHC, ß-MHC, transforming growth factor beta 1 (TGF-ß1), collagen-I, collagen-III and NF-γB were examined. Results: Morphological and haemodynamic measurements showed that the activation of PPARγ improved the impaired cardiac function and decreased interstitial fibrosis in cardiac remodeling rats. Further results also showed that the activation of PPARγ inhibited the expressions of Brg1 and TGF-ß1 in the cardiac remodeling hearts. The activation of PPARγ also inhibited the proliferation and collagen production of cardiac fibroblasts, and down-regulated the activity of Brg1 and the expression of TGF-ß1 induced by Ang II in cultured neonatal rat cardiomyocytes and cardiac fibroblasts, respectively, through NF-γB pathway. Conclusions: These results suggested that PPARγ activation effectively inhibited cardiac remodeling processes by suppression of Brg1 and TGF-ß1 expressions through NF-γB pathway in the pressure-overloaded hearts induced by abdominal aorta ligation in rats.

Construction and analysis of cardiac hypertrophy-associated lncRNA-mRNA network based on competitive endogenous RNA reveal functional lncRNAs in cardiac hypertrophy

Cardiac hypertrophy (CH) could increase cardiac after-load and lead to heart failure. Recent studies have suggested that long non-coding RNA (lncRNA) played a crucial role in the process of the cardiac hypertrophy, such as Mhrt, TERMINATOR. Some studies have further found a new interacting mechanism, competitive endogenous RNA (ceRNA), of which lncRNA could interact with micro-RNAs (miRNA) and indirectly interact with mRNAs through competing interactions. However, the mechanism of ceRNA regulated by lncRNA in the CH remained unclear. In our study, we generated a global triple network containing mRNA, miRNA and lncRNA, and extracted a CH related lncRNA-mRNA network (CHLMN) through integrating the data from starbase, miRanda database and gene expression profile. Based on the ceRNA mechanism, we analyzed the characters of CHLMN and found that 3 lncRNAs (SLC26A4-AS1, RP11-344E13.3 and MAGI1-IT1) were high related to CH. We further performed cluster module analysis and random walk with restart for the CHLMN, finally 14 lncRNAs had been discovered as the potential CH related disease genes. Our results showed that lncRNA played an important role in the CH and could shed new light to the understanding underlying mechanisms of the CH.

M3 subtype of muscarinic acetylcholine receptor promotes cardioprotection via the suppression of miR-376b-5p.

The M3 subtype of muscarinic acetylcholine receptors (M3-mAChR) plays a protective role in myocardial ischemia and microRNAs (miRNAs) participate in many cardiac pathophysiological processes, including ischemia-induced cardiac injury. However, the role of miRNAs in M3-mAChR mediated cardioprotection remains unexplored. The present study was designed to identify miRNAs that are involved in cardioprotective effects of M3-mAChR against myocardial ischemia and elucidate the underlying mechanisms. We established rat model of myocardial ischemia and performed miRNA microarray analysis to identify miRNAs involved in the cardioprotection of M3-mAChR. In H9c2 cells, the viability, intracellular free Ca2+ concentration ([Ca2+]i), intracellular reactive oxygen species (ROS), miR-376b-5p expression level, brain derived neurophic factor (BDNF) and nuclear factor kappa-B (NF-κB) levels were measured. Our results demonstrated that M3-mAChR protected myocardial ischemia injury. Microarray analysis and qRT-PCR revealed that miR-376b-5p was significantly up-regulated in ischemic heart tissue and the M3-mAChRs agonist choline reversed its up-regulation. In vitro, miR-376b-5p promoted H2O2-induced H9c2 cell injuries measured by cells viability, [Ca2+]i and ROS. Western blot and luciferase assay identified BDNF as a direct target of miR-376b-5p. M3-mAChR activated NF-κB and thereby inhibited miR-376b-5p expression. Our data show that a novel M3-mAChR/NF-κB/miR-376b-5p/BDNF axis plays an important role in modulating cardioprotection. MiR-376b-5p promotes myocardial ischemia injury possibly by inhibiting BDNF expression and M3-mAChR provides cardioprotection at least partially mediated by the downregulation of miR-376b-5p through NF-κB. These findings provide new insight into the potential mechanism by which M3-mAChR provides cardioprotection against myocardial ischemia injury.

Crucial Role of Calcium-Sensing Receptor Activation in Cardiac Injury of Diabetic Rats

Cardiac injury is a common pathological change frequently accompanied by diabetes mellitus. Recently, some evidence indicated that calcium-sensing receptor (CaSR) expressed in the cardiac tissue. However, the functional role of CaSR in diabetic cardiac injury remains unclear. The present study was designed to investigate the relationship between CaSR activation and diabetes-induced cardiac injury. Diabetic model was successfully established by administration of streptozotocin (STZ) in vivo, and cardiomyocyte injury was simulated by 25.5 mM glucose in vitro. Apoptotic rate, intracellular calcium concentration ([Ca2+]i) and the expression of Bcl-2, Bax, extracellular signal-regulated protein kinase (ERK), c-Jun NH2-terminal protein kinase (JNK), and p38 were examined. We demonstrated a significant increase in left ventricular end-diastolic pressure (LVEDP) as well as decrease in maximum rate of left ventricular pressure rise and fall (±dp/dtmax), and left ventricular systolic pressure (LVSP), apoptosis of cardiomyocytes was also observed by TUNEL staining. In vitro, 25.5 mM glucose-induced apoptosis was detected by flow cytometry in neonatal rat cardiomyocytes. Further results showed that 25.5 mM glucose significantly increased [Ca2+]i, up-regulated the expression of Bax, P-ERK and P-JNK, and suppressed Bcl-2 expression. However, the above deleterious changes were further confirmed when co-treatment with CaSR agonist GdCl3 (300 µM). But the effects of GdCl3 were attenuated by 10 µM NPS-2390, a specific CaSR inhibitor. When CaSR was silence by siRNA transfection, the effects of high glucose were inhibited. These results suggest that CaSR activation could lead to the apoptosis of cardiomyocytes in diabetic cardiac injury through the induction of calcium overload, the activation of the mitochondrial, and mitogen-activated protein kinase pathway.

Carvacrol inhibits proliferation and induces apoptosis in human colon cancer cells.

Colon cancer is one of the most common malignancies worldwide and has a high mortality rate. Carvacrol is a major component of oregano and thyme essential oils and shows antitumor properties. Here, we investigated the effects of carvacrol on the proliferation and apoptosis of two human colon cancer cell lines, HCT116 and LoVo, and studied the molecular mechanisms of its antitumor properties. We found that carvacrol inhibited the proliferation and migration of the two colon cancer cell lines in a concentration-dependent manner. Cell invasion was suppressed after carvacrol treatment by decreasing the expression of matrix metalloprotease-2 (MMP-2) and MMP-9. Carvacrol treatment also caused cell cycle arrest in the G2/M phase and decreased cyclin B1 expression. Finally, carvacrol induced cell apoptosis in a dose-dependent manner. At the molecular level, carvacrol downregulated the expression of Bcl-2 and induced the phosphorylation of the extracellular-regulated protein kinase and protein kinase B (p-Akt). In parallel, carvacrol upregulated the expression of Bax and c-Jun N-terminal kinase. These results indicate that carvacrol might induce apoptosis in colon cancer cells through the mitochondrial apoptotic pathway and the MAPK and PI3K/Akt signaling pathways. Together, our results suggest that carvacrol may have therapeutic potential for the prevention and treatment of colon cancer.

Baicalin alleviates ischemia-induced memory impairment by inhibiting the phosphorylation of CaMKII in hippocampus.

Baicalin has a significant neuroprotective effect in stroke. However, the mechanism remains unclear. This study was to reveal the mechanisms by which baicalin protected hippocampal neurons and improved learning and memory impairment after global cerebral ischemia/reperfusion in gerbil. In the present study, the Morris water maze test showed that baicalin significantly improved learning and memory impairment after global cerebral ischemia/reperfusion in gerbils. Laser scanning confocal fluorescence microscope examination showed that baicalin suppressed OGD-induced augmentation of intracellular calcium concentration. Western blotting analysis indicated that baicalin suppressed ischemia-caused elevated phosphorylation level of CaMKII in vivo, in hippocampal neurons in culture, and in SH-SY5Y cells in culture. Western blotting, TUNEL and RNA interference technology were applied to detect effects of baicalin on neuronal apoptosis. We found that baicalin, a CaMKII inhibitor and knocking down the CaMKII prevented OGD-induced apoptosis of hippocampal or SH-SY5Y cells in culture. Therefore, these results suggested that baicalin improves learning and memory impairment induced by global cerebral ischemia/reperfusion in gerbils via attenuating the phosphorylation level of CaMKII and further preventing hippocampal neuronal apoptosis.

Overexpression of TRPV3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer

(1) Background: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca2+-permeant channels. The proteins of some TRP channels are highly expressed in cancer cells. This study aimed to assess the clinical significance and biological functions of TRPV3 in non-small cell lung cancer (NSCLC); (2) Methods: Immunohistochemistry was used to detect the expression of TRPV3 in NSCLC tissues and adjacent noncancerous lung tissues. Western blot was used to detect the protein expressions of TRPV3, CaMKII, p-CaMKII, CyclinA, CyclinD, CyclinE1, CDK2, CDK4, and P27. Small interfering RNA was used to deplete TRPV3 expression. A laser scanning confocal microscope was used to measure intracellular calcium concentration ([Ca2+]i). Flow cytometry was used to analyze cell cycle; (3) Results: TRPV3 was overexpressed in 65 of 96 (67.7%) human lung cancer cases and correlated with differentiation (p = 0.001) and TNM stage (p = 0.004). Importantly, TRPV3 expression was associated with short overall survival. In addition, blocking or knockdown of TRPV3 could inhibit lung cancer cell proliferation. Moreover, TRPV3 inhibition could decrease [Ca2+]i of lung cancer cells and arrest cell cycle at the G1/S boundary. Further results revealed that TRPV3 inhibition decreased expressions of p-CaMKII, CyclinA, CyclinD1, CyclinE, and increased P27 level; (4) Conclusions: Our findings demonstrate that TRPV3 was overexpressed in NSCLC and correlated with lung cancer progression. TRPV3 activation could promote proliferation of lung cancer cells. TRPV3 might serve as a potential companion drug target in NSCLC.

Role of carvacrol in cardioprotection against myocardial ischemia/reperfusion injury in rats through activation of MAPK/ERK and Akt/eNOS signaling pathways

ABSTRACT Carvacrol (CAR) is a compound isolated from some essential oils, many studies have demonstrated its therapeutic potential on different diseases. This study aims to evaluate the protective effect of CAR against myocardial ischemia/reperfusion (I/R) injury in rats. Male adult rats underwent ligation of the left anterior descending coronary artery (LAD) in I/R models. Rats were treated with CAR after LAD. The levels of I/R‐ induced infarct size, cardiomyocyte apoptosis and cardiac functional impairment were examined. Levels of superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) were detected by western blotting. Cardiomyocytes induced by hypoxic reperfusion (H/R) injury were tested by Hoechst 33258. Our results revealed that CAR administration significantly protected the heart function, attenuated myocardial infarct size, increased SOD and CAT levels, reduced MDA level and especially decreased cardiomyocytes apoptosis. Western blotting showed that CAR treatment up‐regulated phosphorylated ERK (p‐ERK), while producing no impact onp38 mitogen‐activated protein kinase (p38MAPK) and c‐Jun N‐terminal kinase (JNK). The cardioprotection of CAR was reversed by the ERK inhibitor PD‐98059, demonstrating the involvement of the MAPK/ERK pathway in the anti‐apoptotic mechanisms of CAR. Besides, the results in vitro also showed the protective efficiency of CAR on cardiomyocytes H/R injury. Furthermore, pretreatment with CAR markedly increased the activation of Akt/eNOS pathway in cardiomyocytes subjected to H/R, and the protective effects of CAR were abolished in the presence of the Akt inhibitor LY294002. Therefore, the cardioprotective effects of CAR may be attributed to its antioxidant and antiapoptotic activities through activations of the MAPK/ERK and Akt/eNOS signaling pathways.

The Antiarrhythmic Effect and Possible Ionic Mechanisms of Pilocarpine on Animal Models

This study was designed to evaluate the effects of pilocarpine and explore the underlying ionic mechanism, using both aconitine-induced rat and ouabain-induced guinea pig arrhythmia models. Confocal microscopy was used to measure intracellular free-calcium concentrations ([Ca2+]i) in isolated myocytes. The current data showed that pilocarpine significantly delayed onset of arrhythmias, decreased the time course of ventricular tachycardia and fibrillation, reduced arrhythmia score, and increased the survival time of arrhythmic rats and guinea pigs. [Ca2+]i overload induced by aconitine or ouabain was reduced in isolated myocytes pretreated with pilocarpine. Moreover, M3-muscarinic acetylcholine receptor (mAChR) antagonist 4-DAMP (4-diphenylacetoxy-N-methylpiperidine-methiodide) partially abolished the beneficial effects of pilocarpine. These data suggest that pilocarpine produced antiarrhythmic actions on arrhythmic rat and guinea pig models induced by aconitine or ouabain via stimulating the cardiac M3-mAChR. The mechanism may be related to the improvement of Ca2+ handling.

Carvacrol induces the apoptosis of pulmonary artery smooth muscle cells under hypoxia.

The abnormal apoptosis of pulmonary artery smooth muscle cells (PASMCs) is an important pathophysiological process in pulmonary vascular remodeling and pulmonary arterial hypertension (PAH). Carvacrol, an essential oil compound from oregano and thyme, has displayed antimicrobial, antitumor, and antioxidant properties. Although carvacrol has pro-apoptosis properties in tumor cells, the underlying mechanisms of carvacrol in PASMC apoptosis remain unclear. Thus, in this study, we aim to investigate the role of carvacrol in pulmonary vascular remodeling and PASMC apoptosis in hypoxia. Right Ventricular Hypertrophy Measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery increased in chronic hypoxia and were reversed by carvacrol treatment under hypoxia. Additionally, carvacrol inhibited PASMC viability, attenuated oxidative stress, induced mitochondria membrane depolarization, increased the percentage of apoptotic cells, suppressed Bcl-2 expression, decreased procaspase-3 expression, promoted caspase-3 activation, and inhibited the ERK1/2 and PI3K/Akt pathway. Taken together, these findings suggest that carvacrol attenuates the pulmonary vascular remodeling and promotes PASMC apoptosis by acting on, at least in part, the intrinsic apoptotic pathway. This process might provide us new insight into the development of hypoxic pulmonary hypertension.