miR-200a-3p overexpression alleviates diabetic cardiomyopathy injury in mice by regulating autophagy through the FOXO3/Mst1/Sirt3/AMPK axis.

Objective: Hyperglycemia and insulin resistance or deficiency are characteristic features of diabetes. Diabetes is accompanied by cardiomyocyte hypertrophy, fibrosis and ventricular remodeling, and eventually heart failure. In this study, we established a diabetic cardiomyopathy (DCM) mouse model to explore the role and mechanism of miR-200a-3p in DCM. Methods: We used db/db mice to simulate the animal model of DCM and the expression of miR-200a-3p was then examined by RT-qPCR. Tail vein injection of mice was done with rAAV-miR-200a-3p for 8 weeks, and cardiac function was assessed by cardiac ultrasound. The levels of myocardial tissue injury, fibrosis, inflammation, apoptosis and autophagy in mice were detected by histological staining, TUNEL and other molecular biological experiments. Results: miR-200a-3p expression levels were significantly decreased in the myocardium of DCM mice. Diabetic mice developed cardiac dysfunction and presented pathological changes such as myocardial injury, myocardial interstitial fibrosis, cardiomyocyte apoptosis, autophagy, and inflammation. Overexpression of miR-200a-3p expression significantly ameliorated diabetes induced-cardiac dysfunction and myocardial injury, myocardial interstitial fibrosis, cardiomyocyte apoptosis, and inflammation, and enhanced autophagy. Mechanistically, miR-200a-3p interacted with FOXO3 to promote Mst1 expression and reduce Sirt3 and p-AMPK expression. Conclusion: In type 2 diabetes, increased miR-200a-3p expression enhanced autophagy and participated in the pathogenic process of cardiomyopathy throug7 Mst1/Sirt3/AMPK axis regulation by its target gene FOXO3. This conclusion provides clues for the search of new gene targeted therapeutic approaches for diabetic cardiomyopathy.

Effect of miR-499-5p/SOX6 axis on atrial fibrosis in rats with atrial fibrillation.

Atrial fibrosis is involved in the progression of atrial fibrillation (AF). miR-499-5p is the most downregulated microRNA in arrhythmogenic cardiomyopathy hearts. Sry-related high-mobility-group box 6 (SOX6) is associated with apoptosis, inflammatory responses, and fibrosis. This study investigated the mechanism of miR-499-5p in ameliorating AF rats by regulating SOX6. AF rat models were established by injecting Ach-CaCl2 mixture, and the rats were treated with Lv-miR-499-5p/oe-SOX6/si-SOX6 before modeling. AF duration was recorded using electrocardiogram. miR-499-5p and SOX6 expression levels in the myocardium were determined by reverse transcription-quantitative polymerase chain reaction. The binding of miR-499-5p and SOX6 was validated. The atrial fibrosis degree and cardiomyocyte apoptosis were assessed using the Masson and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining methods. Levels of SOX6, atrial fibrosis markers (collage I/α-SMA/TGFß1), cell cycle-related proteins (p21/CDC25/Cyclin B1), and cell senescence markers (SA-ß-gal/γ-H2AX) were measured using Western blotting and immunohistochemistry. miR-499-5p was downregulated and SOX6 was upregulated in AF rats. miR-499-5p overexpression shortened the AF duration, alleviated atrial fibrosis, and decreased collage I/α-SMA/TGFß1. miR-499-5p targeted SOX6 to ameliorate atrial fibrosis. AF rats exhibited increased p21/CDC25/Cyclin B1/SA-ß-gal/γ-H2AX levels and raised cardiomyocyte apoptosis. SOX6 silencing downregulated p21 and alleviated cardiomyocyte cycle arrest, cell senescence, and apoptosis in AF rats. Shortly, miR-499-5p suppresses atrial fibrosis and cardiomyocyte senescence by targeting SOX6 and downregulating p21, thus mitigating AF in rats.

TIPE2 protects cardiomyocytes from ischemia-reperfusion-induced apoptosis by decreasing cell autophagy via the mTORC1 signaling pathway.

In cardiac ischemia-reperfusion (I/R), autophagy of hyperactivated cardiomyocytes degrades normal proteins and organelles, destroys cells and causes irreversible cell death. The present study aimed to determine the molecular mechanism through which TNF-α-induced protein 8-like protein 2 (TIPE2) regulates cardiomyocyte apoptosis via autophagy in I/R. The results revealed that the number of apoptotic cells and the protein expression levels of TIPE2 in the heart tissue of I/R model mice were significantly increased. In vitro, the overexpression of TIPE2 decreased oxygen glucose deprivation (OGD)-induced autophagy, apoptosis and activation of the mTOR complex 1 (mTORC1) signaling pathway in H9c2 cells. Treatment with the mTORC1 inhibitor not only inhibited the TIPE2-activated mTORC1 signaling pathway, but also increased OGD-induced autophagy and apoptosis of H9c2 cells. In conclusion, the results of the present study revealed that TIPE2 may protect cardiomyocytes from I/R-induced apoptosis by decreasing cell autophagy via the mTORC1 signaling pathway.

A Novel Approach for Repetitive Dislocation of Transvenous Left Ventricular Leads During Cardiac Resynchronization Therapy Implantation by the Loop Technique.

Cardiac resynchronization therapy (CRT) for heart failure requires transvenous insertion of a left ventricular pacing lead through the coronary sinus. However, repeated intraoperative dislocations often occur. Therefore, we describe a novel technique that uses the loop technique to treat patients with repeated intraoperative dislocations during transvenous left ventricular lead implantation to stabilize the lead in its final position. In five patients with repeated intraoperative dislocation during transvenous left ventricular lead implantation, the loop technique was successfully used to stabilize the lead in its final position. The pacing and sensing parameters were satisfactory in all patients at implantation and 12 months post-operatively. Compared with the pre-operative values, the 12-month post-operative values for the left ventricular ejection fraction were significantly increased and the left ventricular end systolic dimension and left ventricular end diastolic dimension were significantly decreased (P < 0.05). The left ventricular ejection fraction of these 5 patients increased by more than 15%. CRT significantly improved the left ventricular structure and function of these 5 patients. During the 1-, 3-, 6-, and 12-month follow-ups, no left ventricular lead dislocations were observed. This loop technique is safe and effective and can be considered for repeated intraoperative dislocation during transvenous left ventricular lead implantation through the coronary sinus of a CRT device.

Analysis of the association and predictive value of hyperhomocysteinaemia for obstructive coronary artery disease.

OBJECTIVE: To investigate the predictive value of hyperhomocysteinaemia (HHcy) for obstructive coronary artery disease (CAD) in an Asian population in northern China. METHODS: This retrospective study enrolled patients at their first cardiac assessment and assigned them to an obstructive CAD group or a non-obstructive CAD group according to the coronary angiography results. HHcy was defined as a homocysteine (Hcy) level > 15 µmol/l. RESULTS: This study enrolled 2987 participants: 1172 in the non-obstructive CAD group and 1815 in the obstructive CAD group. Hcy level in the obstructive CAD group was significantly higher than in the non-obstructive CAD group. The proportion of patients with HHcy in the obstructive CAD group was significantly greater than in the non-obstructive CAD group. Multivariate logistic regression analysis demonstrated that HHcy was independently correlated with obstructive CAD in both young (aged ≤ 55 years) and old patients (aged > 55 years). HHcy showed a higher sensitivity (93.1%), specificity (86.1%) and accuracy (90.0%) for obstructive CAD. The odds ratio for HHcy was 84.2. The Kappa value (0.8) showed substantial agreement between obstructive CAD and HHcy. CONCLUSIONS: HHcy was associated with obstructive CAD and may be a potentially independent risk factor for obstructive CAD with good predictive value.

Case Report: Phloroglucinol-Induced Kounis Syndrome.

Background: Kounis syndrome is an allergy-related acute coronary syndrome that is induced by various pharmacological and environmental factors. Given that many clinicians are not aware of this condition, many cases may be underdiagnosed. We report a case of type II Kounis syndrome induced by phloroglucinol. Case Summary: A 52-year-old man with pre-existing coronary artery stenosis presented with a 30-min history of chest pain and erythematous rash after intramuscular administration of phloroglucinol. An electrocardiogram demonstrated ST-segment elevation in leads II, III and aVF. Emergency coronary angiography revealed severe stenosis in the distal right coronary artery. Intravascular ultrasound showed plaque rupture and thrombosis, and the minimum lumen area was 3.0 mm2. A 3.5 × 38 mm stent was implanted in the distal right coronary artery. Troponin I levels were elevated. A diagnosis of type II Kounis syndrome induced by phloroglucinol was made, and the condition manifested as acute ST-segment elevation myocardial infarction. Conclusions: Clinicians should be aware of Kounis syndrome as a possible diagnosis in a patient who presents with chest pain and allergic manifestations given that an increasing number of triggers are being reported.

Rosmarinic acid ameliorated cardiac dysfunction and mitochondrial injury in diabetic cardiomyopathy mice via activation of the SIRT1/PGC-1α pathway.

Mitochondrial injury plays an essential role in the pathogenesis of diabetic cardiomyopathy (DCM). Previous studies demonstrated that rosmarinic acid (RA) treatment prevented high glucose-induced mitochondrial injury in vitro. However, whether RA can ameliorate cardiac function by preventing mitochondrial injury in DCM is unknown. The SIRT1/PGC-1α pathway has emerged as an important regulator of metabolic control and other mitochondrial functions. The present study was undertaken to determine the effects of RA on mitochondrial and cardiac function in DCM as well as the involvement of the SIRT1/PGC-1α pathway. Our results revealed that RA improved cardiac systolic and diastolic function and prevented mitochondrial injury in DCM, as shown by the reduced blood glucose and lipid levels, increased mitochondrial membrane potential levels, improved adenosine triphosphate synthesis, and inhibited apoptosis (P < 0.05). Moreover, RA upregulated the expression of SIRT1 and PGC-1α in DCM mice and high glucose-treated H9c2 cardiomyocytes (P < 0.05). Further mechanistic studies in H9c2 cardiomyocytes revealed that suppression of SIRT1 by Sh-SIRT1 counteracted the effects of RA on high glucose-induced abnormal metabolism of glucose and lipids, oxidative stress and apoptosis (P < 0.05). Taken together, these data indicate that RA prevented mitochondrial injury and cardiac dysfunction in DCM mice, and the SIRT1/PGC-1α pathway mediated the protective effects of RA.

Lin28a protects against diabetic cardiomyopathy through Mst1 inhibition.

Lin28a has been found to enhance glucose uptake and insulin sensitivity. Lin28a alleviates cardiac dysfunction under various pathological conditions. However, the effects and underlying mechanisms of Lin28a on diabetic cardiomyopathy (DCM) are not well-understood. The aim of this study was to determine whether Lin28a protects against DCM and the potential mechanisms. Two to three days old mouse neonatal primary cardiomyocytes were randomized for treatment with adenoviruses harboring Lin28a and mammalian sterile 20-like kinase 1 (Mst1) short hairpin RNA, 48 hr before culturing in normal or high glucose medium. Cardiomyocyte apoptosis, autophagy, mitochondrial morphology, adenosine triphosphate content, and cytokine levels in the high glucose or normal conditions were observed between all groups. Either Lin28a overexpression or Mst1 knockdown alleviated mitochondrial ultrastructure impairment, decreased cytokine levels, inhibited apoptosis, and enhanced autophagy in primary neonatal mouse cardiomyocytes treated with high glucose. Importantly, the protective effects of Lin28a and Mst1 disappeared after treatment with 3-methyladenine, an autophagy inhibitor. Interestingly, in Mst1 knockdown cardiomyocytes, Lin28a overexpression failed to further enhance autophagy and alleviate high glucose-induced cardiomyocyte injury, which implies the protective roles of Lin28a counteracting high glucose-induced cardiomyocyte injury are dependent on Mst1 inhibition. Furthermore, co-immunoprecipitation and immunofluorescence double staining suggested that there were no direct interactions between Mst1 and Lin28a. Lin28a increased the expression of Akt, which inhibited the activation of Mst1-mediated apoptotic pathways.

Factors Influencing Stent Restenosis After Percutaneous Coronary Intervention in Patients with Coronary Heart Disease: A Clinical Trial Based on 1-Year Follow-Up.

BACKGROUND This study observed the incidence of in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) and discusses the risk factors of ISR based on clinical data, coronary angiography, and stent features, to provide a theoretical basis for the prevention and treatment of ISR. MATERIAL AND METHODS We selected 1132 cases who received stent implantation at the Shaanxi People's Hospital from June 2014 to June 2016 and were followed up by coronary angiography within 1 year. Based on coronary angiography, the cases were divided into ISR and non-ISR groups. ISR was defined as a reduction in lumen diameter by over 50% after PCI. The ISR group consisted of 93 cases and the non-ISR group consisted of 1039 cases. Medical history, biochemical indicators, features of coronary artery lesions, and stent status were analyzed retrospectively. Risk factors of ISR were identified by univariate and multivariate logistic regression analyses. RESULTS Among 1132 cases, 93 cases had ISR, with the overall incidence of 8.21%. Univariate and multivariate logistic regression analyses indicated that postoperative hypersensitive C-reactive protein (hs-CRP) levels (OR=2.309, 1.579-3.375 mg/L), postoperative homocysteine (HCY) levels (OR=2.202, 1.268-3.826 µmol/L), history of diabetes (OR=1.955,1.272-3.003), coronary bifurcation lesions (OR=3.785, 2.246-6.377), and stent length (OR=1.269, 1.179-1.365 mm) were independent risk factors of ISR after PCI (P<0.05). CONCLUSIONS Elevated hs-CRP and HCY levels after PCI, history of diabetes, coronary bifurcation lesions, and greater stent length were associated with a higher risk of ISR. Patients with a higher risk of ISR should receive routine follow-up and intense medication management after PCI to control the risk factors and to reduce ISR.

ZIP8 induces monocyte adhesion to the aortas ex-vivo by regulating zinc influx.

Monocytes recruited and adhering to the inflamed arteries are crucial for atherosclerosis development. Here, we report the role of zinc (Zn2+) homeostasis in monocyte adhesion and recruitment. By comparing the expression levels of Zn2+ transporters between non-adhering and adhering monocytes, we found that the Zn2+ importer ZIP8 was specifically upregulated in monocytes adhering to the aortas ex-vivo. Although the overexpression of ZIP8 increased the absorption of Zn2+, Fe2+ and Cd2+ in monocytes, only Zn2+ supplementation was demonstrated capable of promoting the adhesion of monocytes to endothelial monolayers in vitro. In addition, we confirmed the role of ZIP8-dependent Zn2+ influx in promoting monocyte adhesion to the aortas ex-vivo. More importantly, the enforced expression of ZIP8 increased monocyte adhesion and recruitment to the nascent atherosclerotic lesions in ApoE-/- mice. Overall, our results suggest that the Zn2+ influx in monocytes regulated by ZIP8 is a novel factor determining their adhesion and recruitment to atherosclerotic lesions, and that targeting ZIP8 or Zn2+ homeostasis may represent a novel strategy to interfere these activities.

Peroxisome proliferator-activated receptor γ attenuates serotonin-induced pulmonary artery smooth muscle cell proliferation and apoptosis inhibition involving ERK1/2 pathway.

Serotonin (5-HT) has been shown to be involved in pulmonary vascular remodeling in pulmonary arterial hypertension (PAH) by inducing pulmonary artery smooth muscle cells (PASMCs) proliferation and inhibiting PASMC apoptosis. Peroxisome proliferator-activated receptor γ (PPARγ) plays a crucial role in regulating proliferation and apoptosis of many cell types. Moreover, recently, loss of PPARγ has also been reported to be associated with the development of PAH. The present study is aimed to assess whether PPARγ is involved in 5-HT induced PASMC proliferation and apoptosis inhibition and the possible mechanism. We found that 5-HT could induce PASMC proliferation and inhibit PASMC apoptosis in a dose-dependent manner. Furthermore, we found that 5-HT negatively regulated PPARγ expression and gene promoter activity in PASMCs and 5-HT induced PASMC proliferation and apoptosis resistance could be abolished by PPARγ agonists and enhanced by PPARγ inhibitor. In addition, we found that extracellular signal-regulated kinase (ERK) signaling pathway mediated the 5-HT-induced inhibition of PPARγ expression. Our results might provide novel insights into the mechanisms for the pro-remodeling action of 5-HT in pulmonary vasculature.