RESUMEN
Delayed recovery from ulcerative colitis is mainly due to impaired healing of the intestinal epithelium after inflammation. The circadian rhythm controls cell proliferation and energy metabolism. However, the role of circadian genes in inflammatory bowel disease is largely unknown. The purpose of this study was to investigate whether disrupting the circadian rhythm in mice can worsen colitis by altering mitochondrial energy metabolism. Mice in the experimental groups were under physiologic stress with an 8-h light shift jet-lag schedule every 3 days, whereas those in the control group were not. Subsequently, half of the mice in the control and jet-lagged groups were given dextran sodium sulfate (DSS) to induce colitis. Mice in each group were euthanized at zeitgeber time (ZT)0, ZT4, ZT8, ZT12, ZT16, and ZT20. To investigate the effects of jet lag on the mice, colon specimens were subjected to hematoxylin and eosin staining to analyse mRNA and protein expression of core circadian clock genes (Bmal1, Clock, Per1, Per2, Cry1, Cry2, and Nr1d1). We analysed the mitochondrial morphology, adenosine triphosphate (ATP) levels, and the expression of dynamin-related protein 1 (Drp1) and ser637-phosphorylated (p)-Drp1, which are closely related to ATP production. We further investigated the effect of PER2 knock-down in the colon epithelial cells (CCD 841 CoN) by measuring ATP and cell proliferation levels. Disrupting the circadian rhythm changed the oscillation of clock genes in the colon of mice, altered the mitochondrial morphology of the colon specimens, decreased the expression of p-Drp1, reduced ATP production, and exacerbated inflammatory responses in mice with DSS-induced colitis. Additionally, silencing of PER2 in the colon epithelial cells reduced ATP production and cell proliferation. Disrupting the circadian rhythm in mice decreases mitochondrial energy metabolism in the colon and exacerbates symptoms of colitis.
RESUMEN
Pericytes, as the mural cells surrounding the microvasculature, play a critical role in the regulation of microcirculation; however, how these cells respond to ischemic stroke remains unclear. To determine the temporal alterations in pericytes after ischemia/reperfusion, we used the 1-hour middle cerebral artery occlusion model, which was examined at 2, 12, and 24 hours after reperfusion. Our results showed that in the reperfused regions, the cerebral blood flow decreased and the infarct volume increased with time. Furthermore, the pericytes in the infarct regions contracted and acted on the vascular endothelial cells within 24 hours after reperfusion. These effects may result in incomplete microcirculation reperfusion and a gradual worsening trend with time in the acute phase. These findings provide strong evidence for explaining the "no-reflow" phenomenon that occurs after recanalization in clinical practice.
RESUMEN
The metabolic profiles of Panax quinquefolius and its associated therapeutic values are critically affected by the repetitious steaming times. The times-dependent steaming effect of P. quinquefolius is not well-characterized and there is also no official guideline on its times of steaming. In this paper, a UPLC-Q-TOF-MS/MS method was developed for the qualitative profiling of multi-parametric metabolic changes of raw P. quinquefolius during the repetitious steaming process. Our method was successful in discriminating the differentially multi-steamed herbs. Meantime, the repetitious steaming-inducing chemical transformations in the preparation of black American ginseng (American ginseng that was subjected to 9 cycles of steaming treatment) were evaluated by this UPLC-Q-TOF-MS/MS based chemical profiling method. Under the optimized UPLC-Q-TOF-MS/MS conditions, 29 major ginsenosides were unambiguously identified and/or tentatively assigned in both raw and multi-steamed P. quinquefolius within 19 min, among them 18 ginsenosides were detected to be newly generated during the preparatory process of black American ginseng. The mechanisms involved were further deduced to be hydrolysis, dehydration, decarboxylation and addition reactions of the original ginsenosides in raw P. quinquefolius through analyzing mimic 9 cycles of steaming extracts of 14 pure reference ginsenosides. Our novel steaming times-dependent metabolic profiling approach represents the paradigm shift in the global quality control of multi-steamed P. quinquefolius products.
