Authors:Q. Zhang, Z. Qian, L. Pan, H. Li, and H. Zhu
Berberine, a primary pharmacological active constitute of Coptidis Rhizoma, could inhibit neuronal apoptosis in cerebral ischemia. Here, we aimed to investigate whether and how HIF-1 is implicated in the anti-apoptosis effect of berberine on neurons under hypoxia/ischemia. Viability of PC12 cells treated with berberine prior to or following CoCl2-induced hypoxia was evaluated. Annexin V-PI staining was employed to analyse cell apoptosis ratio. HIF-1α and apoptosis-associated molecules were detected via Western blotting. TUNEL and immunohistochemistry were used to demonstrate apoptosis, HIF-1α and p53 levels in cerebral tissue of middle cerebral artery occlusion (MCAO) rats. Berberine pretreatment promoted PC12 cells survival and inhibited apoptosis under hypoxia condition. At the same time, it decreased cell viability and enhancement of apoptosis were observed with berberine treatment under hypoxia. Decreased HIF-1α, caspase 9, caspase 3 and increased Bcl-2/Bax ratio were responsible for the anti-apoptosis of berberine pretreatment. However, pro-apoptosis by berberine under hypoxia was indicated with opposing regulation of those molecules. Significant reduction of apoptosis, HIF-1α and p53 were found in cerebral tissue of MCAO rats treated with berberine. The present study suggests that berberine regulates neuronal apoptosis in cerebral ischemia, which might be dependent on the degree of cell injury. HIF-1 and the followed apoptotic pathway are involved in those effects of berberine.
Authors:D-Y Zhao, Q-Q Qi, X Long, X Li, F-X Chen, Y-B Yu, and X-L Zuo
Impaired intestinal barrier function has been demonstrated in the pathophysiology of diarrhea-predominant irritable bowel syndrome (IBS-D). This study aimed to describe the intestinal ultrastructural findings in the intestinal mucosal layer of IBS-D patients.
In total, 10 healthy controls and 10 IBS-D patients were analyzed in this study. The mucosa of each patient’s rectosigmoid colon was first assessed by confocal laser endomicroscopy (CLE); next, biopsied specimens of these sites were obtained. Intestinal tissues of IBS-D patients and healthy volunteers were examined to observe cellular changes by transmission electron microscopy (TEM).
CLE showed no visible epithelial damage or inflammatory changes in the colonic mucosa of IBS-D compared with healthy volunteers. On transmission electron microscopic examination, patients with IBS-D displayed a larger apical intercellular distance with a higher proportion of dilated (>20 nm) intercellular junctional complexes, which was indicative of impaired mucosal integrity. In addition, microvillus exfoliation, extracellular vesicle as well as increased presence of multivesicular bodies were visible in IBS-D patients. Single epithelial cells appeared necrotic, as characterized by cytoplasmic vacuolization, cytoplasmic swelling, and presence of autolysosome. A significant association between bowel habit, frequency of abdominal pain, and enlarged intercellular distance was found.
This study showed ultrastructural alterations in the architecture of intestinal epithelial cells and intercellular junctional complexes in IBS-D patients, potentially representing a pathophysiological mechanism in IBS-D.