The Pacific white shrimp, Litopenaeus vannamei, is widely farmed in China. Salinity is a major environmental factor that affects its growth and distribution. Crustacean hyperglycemic hormone is verified to participate...The Pacific white shrimp, Litopenaeus vannamei, is widely farmed in China. Salinity is a major environmental factor that affects its growth and distribution. Crustacean hyperglycemic hormone is verified to participate in ion transport in response to the salinity challenge mediated by endocrine neurotransmitters(biogenic amines, BAs). In the present study, the contents of BAs and expressions of their receptors were detected in gills of Litopenaeus vannamei exposed to low salinity. The intracellular signaling molecules such as cyclic adenosine monophosphate(cAMP), protein kinase A(PKA), 14-3-3 protein, FXYD2 protein and cAMP response element-binding protein(CREB) were detected. The effects of low salinity on the expressions of Na^+-K^+-ATPase, Na^+/K^+/2 Cl-co-transporter and Cl-transporter and activity of Na^+-K^+-ATPase were also analyzed. The results showed that dopamine and epinephrine concentrations and their receptor expressions were significantly affected by low salinity. The changes of c AMP and PKA were obvious and the expressions of 14-3-3 and FXYD2 peaked at early stages. However, the expression of CREB was only significantly up-regulated on day 9. The activity and expression of Na^+-K^+-ATPase(α subunit) reached a peak on day 1. The expressions of Na^+/K^+/2 Cl-co-transporter and Cl-transporter up-regulated obviously. It suggests that BAs can activate the cAMP-PKA pathway, which further acts on the 14-3-3 and FXYD2 proteins, and ultimately improve the activity of Na^+-K^+-ATPase. Furthermore, after BAs stimulate the cAMP-PKA pathway, PKA phosphorylates the transcription factor CREB and regulates the expressions of ion transport enzymes/transporters. The results in this study are helpful for understanding the response mechanism of endocrine neurotransmitters on osmoregulation in crustaceans.展开更多
Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities...Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities ranging from subclinical alterations to coma.HE is caused by the diversion of portal blood into systemic circulation through portosystemic collateral vessels.Thus,the brain is exposed to intestinal-derived toxic substances.Moreover,the strategies to prevent advancement and improve the prognosis of such a liver-brain disease rely on intestinal microbial modulation.This is supported by the findings that antibiotics such as rifaximin and laxative lactulose can alleviate hepatic cirrhosis and/or prevent HE.Together,the significance of the gut-liver-brain axis in human health warrants attention.This review paper focuses on the roles of bacteria metabolites,mainly ammonia and bile acids(BAs)as well as BA receptors in HE.The literature search conducted for this review included searches for phrases such as BA receptors,BAs,ammonia,farnesoid X receptor(FXR),G protein-coupled bile acid receptor 1(GPBAR1 or TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cirrhosis in conjunction with the phrase hepatic encephalopathy and portosystemic encephalopathy.PubMed,as well as Google Scholar,was the search engines used to find relevant publications.展开更多
基金supported by State Oceanic Administration Specific Public Project of China (No. 201305005)the National Natural Science Foundation of China (No. 31072193)
文摘The Pacific white shrimp, Litopenaeus vannamei, is widely farmed in China. Salinity is a major environmental factor that affects its growth and distribution. Crustacean hyperglycemic hormone is verified to participate in ion transport in response to the salinity challenge mediated by endocrine neurotransmitters(biogenic amines, BAs). In the present study, the contents of BAs and expressions of their receptors were detected in gills of Litopenaeus vannamei exposed to low salinity. The intracellular signaling molecules such as cyclic adenosine monophosphate(cAMP), protein kinase A(PKA), 14-3-3 protein, FXYD2 protein and cAMP response element-binding protein(CREB) were detected. The effects of low salinity on the expressions of Na^+-K^+-ATPase, Na^+/K^+/2 Cl-co-transporter and Cl-transporter and activity of Na^+-K^+-ATPase were also analyzed. The results showed that dopamine and epinephrine concentrations and their receptor expressions were significantly affected by low salinity. The changes of c AMP and PKA were obvious and the expressions of 14-3-3 and FXYD2 peaked at early stages. However, the expression of CREB was only significantly up-regulated on day 9. The activity and expression of Na^+-K^+-ATPase(α subunit) reached a peak on day 1. The expressions of Na^+/K^+/2 Cl-co-transporter and Cl-transporter up-regulated obviously. It suggests that BAs can activate the cAMP-PKA pathway, which further acts on the 14-3-3 and FXYD2 proteins, and ultimately improve the activity of Na^+-K^+-ATPase. Furthermore, after BAs stimulate the cAMP-PKA pathway, PKA phosphorylates the transcription factor CREB and regulates the expressions of ion transport enzymes/transporters. The results in this study are helpful for understanding the response mechanism of endocrine neurotransmitters on osmoregulation in crustaceans.
基金the USA National Institutes of Health(NIH)R01CA222490.
文摘Over 20%of mortality during acute liver failure is associated with the development of hepatic encephalopathy(HE).Thus,HE is a complication of acute liver failure with a broad spectrum of neuropsychiatric abnormalities ranging from subclinical alterations to coma.HE is caused by the diversion of portal blood into systemic circulation through portosystemic collateral vessels.Thus,the brain is exposed to intestinal-derived toxic substances.Moreover,the strategies to prevent advancement and improve the prognosis of such a liver-brain disease rely on intestinal microbial modulation.This is supported by the findings that antibiotics such as rifaximin and laxative lactulose can alleviate hepatic cirrhosis and/or prevent HE.Together,the significance of the gut-liver-brain axis in human health warrants attention.This review paper focuses on the roles of bacteria metabolites,mainly ammonia and bile acids(BAs)as well as BA receptors in HE.The literature search conducted for this review included searches for phrases such as BA receptors,BAs,ammonia,farnesoid X receptor(FXR),G protein-coupled bile acid receptor 1(GPBAR1 or TGR5),sphingosine-1-phosphate receptor 2(S1PR2),and cirrhosis in conjunction with the phrase hepatic encephalopathy and portosystemic encephalopathy.PubMed,as well as Google Scholar,was the search engines used to find relevant publications.
