LEE, Y. | Search bioRxiv

bioRxiv2025

Transmembrane channel-like proteins regulate crop size and contraction dynamics during Drosophila feeding

Feeding regulation in Drosophila involves complex interactions between mechanosensory and neuroendocrine pathways. Our study identified transmembrane channel-like (TMC) proteins as key regulators of crop size and contraction, functioning through distinct neuronal populations. They influence crop size via diuretic hormone, Dh44-expressing neuroendocrine cells in the pars intercerebralis (PI) region and regulate crop contraction through the serotonin receptor 5-HT7. We found that TMC proteins are broadly expressed from the gut to the brain, reinforcing their role in the brain-gut axis. Mechanotransduction channels, including NompC, Piezo, and TMC, facilitate food ingestion, with TMC channels playing an additional role in food storage and transport. We noted the coexpression of piezo with Dh44 in only two neurons, indicating that at least two Dh44 cells are required for crop size regulation. Moreover, we identified Dh44R2 as the key receptor regulating crop size. Unlike DH44 and Piezo, TMC, 5-HT7, and TRP{gamma} are essential for crop contraction, suggesting that these channels serve as therapeutic targets for regulating food intake. Our findings also support the involvement of a mechanosensory serotonergic pathway in regulating crop physiology, integrating sensory and neuroendocrine signals to control food storage and transport. These findings advance our understanding of the neuronal and molecular mechanisms underlying feeding behavior in Drosophila and provide a foundation for exploring conserved pathways that regulate food intake in other organisms, including mammals.

physiology↗

bioRxiv2019

6-O-galloylsalidroside, an active ingredient from Acer tegmentosum, ameliorates alcoholic steatosis and liver injury in a mouse model of chronic ethanol consumption

We previously reported that Acer tegmentosum extract, which is traditionally used to treat liver disease in Korea, may help reduce fat accumulation, improve liver metabolism, and suppress inflammation in alcoholic liver disease. The active ingredient was found to be 6-O-galloylsalidroside, which was isolated from the methanol extract of A. tegmentosum. We hypothesized that 6-O-galloylsalidroside extracted from A. tegmentosum may help protect from liver damage and attenuate hepatic fat accumulation associated with chronic alcohol consumption. In the present study, we aimed to investigate whether 6-O-galloylsalidroside can regulate alcoholic fatty liver and liver injury in mice. For this purpose, mice were fed with Lieber-DeCarli 5% ethanol diet for 11 days to induce steatosis and liver injury. Oral 6-O-galloylsalidroside was administered once a day for 11 days. Intrahepatic lipid accumulation caused by alcohol consumption was measured using in vivo 1H magnetic resonance imaging. Hepatic steatosis was observed histologically in tissue samples stained with hematoxylin and eosin, as well as Oil Red O. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, as well as the triglyceride content in liver homogenates. On magnetic resonance spectroscopy, 6-O-galloylsalidroside appeared to alleviate alcohol-induced steatosis, which was reflected in decreased hepatic and serum triglyceride levels despite ethanol feeding. Furthermore, 6-O-galloylsalidroside treatment was associated with decreased RNA expression of Cd36, which plays an important role in the development of alcoholic steatosis through the hepatic de novo lipogenesis pathway. Furthermore, treatment with 6-O-galloylsalidroside inhibited the expression of cytochrome P4502E1 and attenuated hepatocellular damage, reflected in reduced ALT and AST levels. These findings suggest that 6-O-galloylsalidroside extracted from A. tegmentosum might serve as a bioactive agent for treating alcoholic fatty liver and liver damage.

biochemistry↗