Piwi‐interacting RNAs (piRNAs), a novel class of small non‐coding RNAs, were first discovered in germline cells and are thought to silence transposons in spermatogenesis. Recently, piRNAs have also been identified in somatic tissues, and aberrant expression of piRNAs in tumor tissues may be implicated in carcinogenesis. However, the function of piR‐823 in colorectal cancer (CRC) remains unclear. Here, we first found that piR‐823 was significantly upregulated in CRC tissues compared with its expression in the adjacent tissues. Inhibition of piR‐823 suppressed cell proliferation, arrested the cell cycle in the G1 phase and induced cell apoptosis in CRC cell lines HCT116 and DLD‐1, whereas overexpression of piR‐823 promoted cell proliferation in normal colonic epithelial cell line FHC. Interestingly, Inhibition of piR‐823 repressed the expression of heat shock protein (HSP) 27, 60, 70. Furthermore, elevated HSPs expression partially abolished the effect of piR‐823 on cell proliferation and apoptosis. In addition, we further demonstrated that piR‐823 increased the transcriptional activity of HSF1, the common transcription factor of HSPs, by binding to HSF1 and promoting its phosphorylation at Ser326. Our study reveals that piR‐823 plays a tumor‐promoting role by upregulating phosphorylation and transcriptional activity of HSF1 and suggests piR‐823 as a potential therapeutic target for CRC.

Pneumatosis cystoides intestinalis (PCI) is characterized by gas-filled cysts in the intestinal submucosa and subserosa. There are few reports of PCI occurring in duodenum and rectum. Here we demonstrated four different endoscopic manifestations of PCI and three cases with intestinal stricture all were successfully managed by medical conservative treatment. There are 6 cases of PCI with varied causes encountered, in which the etiology, endoscopic features, treatment methods and prognosis of patients were studied. One case was idiopathic, while the other one case was caused by exposing to trichloroethylene (TCE), and the remaining four cases were secondary to diabetes, emphysema, therioma and diseases of immune system. Of the six patients, all complained of abdominal distention or diarrhea, three (50%) reported muco-bloody stools, two (33.3%) complained of abdominal pain. In four other patients, PCI occurred in the colon, especially the sigmoid colon, while in the other two patients, it occurred in duodenum and rectum. Endoscopic findings were divided into bubble-like pattern, grape or beaded circular forms, linear or cobblestone gas formation and irregular forms. After combination of medicine and endoscopic treatment, the symptoms of five patients were relieved, while one patient died of malignant tumors. PCI endoscopic manifestations were varied, and radiology combined with endoscopy can avoid misdiagnosis. The primary bubble-like pattern can be cured by endoscopic resection, while removal of etiology combined with drug therapy can resolve majority of secondary cases, thereby avoiding the adverse risks of surgery.

The clearance of activated hepatic stellate cells (HSCs) by apoptosis is critical for the reversibility of hepatic fibrosis. Mitochondrial homeostasis is regulated by mitophagy, which is an efficient way of clearing injured mitochondria that plays an important role in apoptosis. However, the role of mitophagy in apoptosis in HSCs and hepatic fibrosis is still unclear. Here, we show that mitophagy is enhanced in parallel with increased apoptosis in hepatic stellate cells during the reversal of hepatic fibrosis. The inhibition of mitophagy suppressed apoptosis in HSCs and aggravated hepatic fibrosis in mice. In contrast, the activation of mitophagy induced apoptosis in HSCs. Furthermore, we confirmed that BCL-B, which is a member of the BCL-2 family, is a regulator mediating mitophagy-related apoptosis. The knockdown of BCL-B resulted in increased apoptosis and mitophagy in HSCs, while the overexpression of BCL-B caused the opposite effects. BCL-B inhibited the phosphorylation of Parkin (a key regulator of mitophagy) and directly bound phospho-Parkin. Altogether, enhanced mitophagy promotes apoptosis in HSCs during the reversal of hepatic fibrosis. BCL-B suppresses mitophagy in HSCs by binding and suppressing phospho-Parkin, thereby inhibiting apoptosis. BCL-B-dependent mitophagy is a new pathway for the regulation of apoptosis in HSCs during the regression of hepatic fibrosis.