How autophagy, a potential therapeutic target, regulates intestinal inflammation.

Inflammatory bowel disease (IBD) is a group of disorders that cause chronic inflammation in the intestines, with the primary types including ulcerative colitis and Crohn's disease. The link between autophagy, a catabolic mechanism in which cells clear protein aggregates and damaged organelles, and intestinal health has been widely studied. Experimental animal studies and human clinical studies have revealed that autophagy is pivotal for intestinal homeostasis maintenance, gut ecology regulation and other aspects. However, few articles have summarized and discussed the pathways by which autophagy improves or exacerbates IBD. Here, we review how autophagy alleviates IBD through the specific genes (e.g., ATG16L1, IRGM, NOD2 and LRRK2), crosstalk of multiple phenotypes with autophagy (e.g., Interaction of autophagy with endoplasmic reticulum stress, intestinal antimicrobial defense and apoptosis) and autophagy-associated signaling pathways. Moreover, we briefly discuss the role of autophagy in colorectal cancer and current status of autophagy-based drug research for IBD. It should be emphasized that autophagy has cell-specific and environment-specific effects on the gut. One of the problems of IBD research is to understand how autophagy plays a role in intestinal tract under specific environmental factors. A better understanding of the mechanism of autophagy in the occurrence and progression of IBD will provide references for the development of therapeutic drugs and disease management for IBD in the future.

Yuan­zhi­san inhibits tau protein aggregation in an Aß1­40­induced Alzheimer's disease rat model via the ubiquitin­proteasome system.

Yuan­zhi­san (YZS) is a classic type of Traditional Chinese Medicine, which has been reported to aid in the treatment of Alzheimer's disease (AD). The present study aimed to investigate the effects of YZS on tau protein aggregation, a hallmark of AD pathology, and its possible mechanisms. The results demonstrated that YZS improved learning and memory abilities, and decreased the severity of AD pathology in ß­amyloid (Aß1­40)­induced AD rats. Moreover, YZS administration inhibited the hyperphosphorylation of tau protein at Ser199 and Thr231 sites. Several vital enzymes in the ubiquitin­proteasome system (UPS), including ubiquitin­activating enzyme E1a/b, ubiquitin­conjugating enzyme E2a, carboxyl terminus of Hsc70­interacting protein, ubiquitin C­236 terminal hydrolase L1 and 26S proteasome, were all significantly downregulated in AD rats, which indicated an impaired enzymatic cascade in the UPS. In addition, it was identified that YZS treatment partly increased the expression levels of these enzymes in the brains of AD rats. In conclusion, the present results suggested that YZS could effectively suppress the hyperphosphorylation of tau proteins, which may be partially associated with its beneficial role in restoring functionality of the UPS.