SWOLLEN TAPETUM AND STERILITY 1 is required for tapetum degeneration and pollen wall formation in rice.

The pollen wall is important for protecting the male gametophyte and for fertilization. The lipid components of the pollen wall are mainly synthesized and transported from the sporophytic tapetum. Although several factors related to lipid biosynthesis have been characterized, the molecular mechanisms underlying lipid biosynthesis during pollen development in rice (Oryza sativa L.) remain elusive. Here, we showed that mutation in the SWOLLEN TAPETUM AND STERILITY 1 (STS1) gene causes delayed tapetum degradation and aborted pollen wall formation in rice. STS1 encodes an endoplasmic reticulum (ER)-localized protein that contains domain of unknown function (DUF) 726 and exhibits lipase activity. Lipidomic and transcriptomic analyses showed that STS1 is involved in anther lipid homeostasis. Moreover, STS1 interacts with Polyketide Synthase 2 (OsPKS2) and Acyl-CoA Synthetase 12 (OsACOS12), two enzymes crucial in lipidic sporopollenin biosynthesis in pollen wall formation, suggesting a potentially lipidic metabolon for sporopollenin biosynthesis in rice. Collectively, our results indicate that STS1 is an important factor for lipid biosynthesis in reproduction, providing a target for the artificial control of male fertility in hybrid rice breeding and insight into the function of DUF726-containing protein in plants.

A New Participant in the Pathogenesis of Alcoholic Gastritis: Pyroptosis.

BACKGROUND/AIMS: Alcohol abuse exerts deleterious effects on the internal organs of the body, and alcohol-related gastritis is a common disease for which prompt treatment is essential to prevent the condition from growing worse. However, the therapeutic methods have some adverse effects. Determining the pathogenic mechanisms of alcoholic gastritis is therefore essential. METHODS: The MTT assay was developed in order to determine the optimal concentration of alcohol needed to treat gastric mucosal cells. The effects of alcohol on the gastric mucosal cells were determined by qRT-PCR and western blot. The release of IL-1ß and IL-18 were determined by ELISA assay. The immunofluorescence assay was used to detect caspase-1 activation levels, while immunohistochemical assay and HE staining were performed to identify the effectiveness of the caspase-1 inhibitor on alcoholic gastritis. The TUNEL assay was used to determine DNA fragmentation. RESULTS: Here, we clarified that ethanol treatment could cause cell DNA damage, activate caspase-1, and promote the generation and release of IL-1ß and IL-18. In other words, ethanol could induce pyroptosis. Interestingly, a caspase-1 inhibitor could significantly suppress pyroptosis, decrease the release of inflammatory cytokines induced by ethanol, and cause no side effects in vivo and in vitro. CONCLUSION: Collectively, our results showed that pyroptosis is involved in the pathogenesis of alcohol-induced gastritis and that caspase-1 inhibitor Ac-yvad-cmk could effectively decrease the damage caused by alcohol, making it a potentially promising agent for the treatment of alcoholic gastritis.