ABSTRACT
Myocardial ischemia-reperfusion (I/R) injury is a pathological process characterized by cardiomyocyte apoptosis, which leads to cardiac dysfunction. Increasing evidence shows that abnormal expression of long noncoding RNAs (lncRNAs) plays a crucial role in cardiovascular diseases. In this study we investigated the role of lncRNAs in myocardial I/R injury. Myocardial I/R injury was induced in mice by ligating left anterior descending coronary artery for 45 min followed by reperfusion for 24 h. We showed that lncRNA KnowTID_00006395, termed lncRNA-6395 was significantly upregulated in the infarct area of mouse hearts following I/R injury as well as in H2O2-treated neonatal mouse ventricular cardiomyocytes (NMVCs). Overexpression of lncRNA-6395 led to cell apoptosis and the expression change of apoptosis-related proteins in NMVCs, whereas knockdown of lncRNA-6395 attenuated H2O2-induced cell apoptosis. LncRNA-6395 knockout mice (lncRNA-6395+/-) displayed improved cardiac function, decreased plasma LDH activity and infarct size following I/R injury. We demonstrated that lncRNA-6395 directly bound to p53, and increased the abundance of p53 protein through inhibiting ubiquitination-mediated p53 degradation and thereby facilitated p53 translocation to the nucleus. More importantly, overexpression of p53 canceled the inhibitory effects of lncRNA-6395 knockdown on cardiomyocyte apoptosis, whereas knockdown of p53 counteracted the apoptotic effects of lncRNA-6395 in cardiomyocytes. Taken together, lncRNA-6395 as an endogenous pro-apoptotic factor, regulates cardiomyocyte apoptosis and myocardial I/R injury by inhibiting degradation and promoting sub-cellular translocation of p53.
Subject(s)
Myocardial Reperfusion Injury , RNA, Long Noncoding , Animals , Apoptosis , Apoptosis Regulatory Proteins/metabolism , Apoptosis Regulatory Proteins/pharmacology , Hydrogen Peroxide/pharmacology , Infarction/pathology , Mice , Mice, Knockout , Myocardial Reperfusion Injury/metabolism , Myocytes, Cardiac , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
Primary hepatic lymphoma is extremely rare, and only a few cases have been described on positron emission tomography (PET) or PET/computed tomography (PET/CT) imaging in the English literature. We report a case of a 55-year-old woman who presented with low-grade fever and weight loss of three months. On CT scanning, a mass was identified which appeared to be a hypoattenuating lesion, on ultrasonographic imaging, the mass was hypoechoic, therefore, liver abscess or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers such as alpha-fetoprotein, carcinoembryonic antigen and carbohydrate antigen 19-9 were within normal limits. PET/CT demonstrated a large abnormal ring-like hypermetabolic focus in the right liver lobe. The lesion was resected and the histopathological findings were consistent with lymphoma. The patient was discharged two weeks after surgery and did not receive any further treatment. After 25 mo follow-up, she is in good health. (18)F-fluorodeoxyglucose PET/CT is useful in confirming the diagnosis of primary hepatic lymphoma by demonstrating no other foci with high uptake in other parts of the body.
