Alterations in sorting and secretion of hepatic apoA5 induce hypertriglyceridemia due to short-term use of olanzapine.

Long-term use of olanzapine, an antipsychotic drug, induces hypertriglyceridemia, resulting in a higher risk of cardiovascular disease. However, the effects and underlying mechanisms of short-term use of olanzapine on circulating triglyceride levels remain poorly understood. Here, the role of apolipoprotein A5 (apoA5), a regulator of triglyceride metabolism, was investigated in olanzapine-induced hypertriglyceridemia. Our multi-center clinical study recruited 36 schizophrenia patients who received short-term (8 weeks) of olanzapine. Besides, female C57BL/6J mice were treated with olanzapine (3 mg/kg/day versus 6 mg/kg/day) for 6 weeks. We demonstrated that short-term use of olanzapine increased plasma triglyceride and decreased plasma apoA5 levels in the patients and mice, with a negative correlation between the two factors. However, no obesity was observed in the patients and mice. Interestingly, olanzapine increased hepatic apoA5 protein in the mice, without significant changes in hepatic Apoa5 mRNA. Consistently, in vitro studies indicated that olanzapine increased medium triglyceride levels and decreased medium apoA5 levels in a dose-dependent manner in human HepG2 cells and primary mouse hepatocytes. Whereas the olanzapine treatment increased hepatic apoA5 protein in vitro, without effects on hepatic APOA5 mRNA. Of note, olanzapine increased the co-localization between apoA5 protein and accumulated lipid droplets in hepatocytes, as opposed to at the hepatocellular plasma membrane, in mouse liver as demonstrated by fluorescence staining. Therefore, our study indicated that short-term use of olanzapine induced hypertriglyceridemia due to defects of sorting and secretion of hepatic apoA5.

Case Report: A Mysterious Giant Thrombus in the Right Atrium in a Patient With Dilated Cardiomyopathy.

An isolated right atrial thrombus is a life-threatening entity that is extremely rare in patients with dilated cardiomyopathy (DCM), which is characterized by a reduced left ventricular function and consequent left ventricular thrombosis. Here, we present the case of a mysterious isolated giant right atrial thrombus in a male patient with DCM. The presence of deep vein thrombosis prompted us to investigate for other underlying diseases for his right atrial thrombus. Interestingly, the elevation of two tumor markers indicated the likelihood of cancer-associated thrombosis. Further, the computed tomography demonstrated a spiculated mass in the lower right lung that was confirmed by an endobronchial biopsy as lung squamous cell carcinoma. Consequently, the giant thrombus in the right atrium should be attributed principally to lung squamous cell carcinoma on the background of DCM. After 3 weeks of enoxaparin, the echocardiogram indicated partial resolution of the thrombus. However, the patient suffered sudden death due to pulmonary embolism.