OBJECTIVE: To explore the effects of taurolithocholic acid (tLCA) and chenodeoxycholic acid (CDCA) on the expression of aorexigenic neuropeptide in mouse hypothalamus GT1-7 cells. METHODS: Mouse hypothalamic GT1-7 cells were treated with culture medium containing 10% FBS (control group, =3) or with 10 nmol/L, 100 nmol/L, 1 μmol/L and 10 μmol/L tLCA (tLCA group, =3) or CDCA (CDCA group, =3) for 12, 24 or 48 h. Real-time PCR was performed to determine the expression levels of proopiomelanocortin (POMC) mRNA in the cells, and the production levels of α-melanocyte-stimulating hormone (α-MSH) were assessed using an ELISA kit. Signal transduction and activator of transcription 3 phosphorylation (p-STAT3), threonine kinase phosphorylation (p-AKT), suppressor of cytokine signaling 3 (SOCS3), G protein-coupled bile acid receptor-1 (TGR5) and farnesoid X receptor (FXR) protein were detected by Western blotting. RESULTS: Western blotting results showed that mouse hypothalamic GT1-7 cells expressed two bile acid receptors, TGR5 and FXR, whose expressions were regulated by bile acids. Real-time PCR showed that the expression of POMC mRNA was significantly increased in the cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. POMC-derived anorexigenic peptide α-MSH increased significantly in GT1-7 cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. Treatment of the cells with tLCA or CDCA significantly increased the expressions of intracellular signaling proteins including p-STAT3, p-AKT and SOCS3. CONCLUSIONS Mouse hypothalamic GT1-7 cells express bile acid receptors TGR5 and FXR. Bile acids tLCA or CDCA can promote the expression of POMC mRNA and increase the production of the anorexigenic peptide α-MSH. The intracellular signaling proteins p-AKT, p-STAT3 and SOCS3 are likely involved in bile acid-induced anorexigenic peptide production.
Animals ; Bile Acids and Salts ; Chenodeoxycholic Acid ; Hypothalamus ; Mice ; Neuropeptides ; Phosphorylation ; STAT3 Transcription Factor ; Signal Transduction ; Suppressor of Cytokine Signaling 3 Protein

OBJECTIVE: To explore the effects of taurolithocholic acid (tLCA) and chenodeoxycholic acid (CDCA) on the expression of aorexigenic neuropeptide in mouse hypothalamus GT1-7 cells. METHODS: Mouse hypothalamic GT1-7 cells were treated with culture medium containing 10% FBS (control group, =3) or with 10 nmol/L, 100 nmol/L, 1 μmol/L and 10 μmol/L tLCA (tLCA group, =3) or CDCA (CDCA group, =3) for 12, 24 or 48 h. Real-time PCR was performed to determine the expression levels of proopiomelanocortin (POMC) mRNA in the cells, and the production levels of α-melanocyte-stimulating hormone (α-MSH) were assessed using an ELISA kit. Signal transduction and activator of transcription 3 phosphorylation (p-STAT3), threonine kinase phosphorylation (p-AKT), suppressor of cytokine signaling 3 (SOCS3), G protein-coupled bile acid receptor-1 (TGR5) and farnesoid X receptor (FXR) protein were detected by Western blotting. RESULTS: Western blotting results showed that mouse hypothalamic GT1-7 cells expressed two bile acid receptors, TGR5 and FXR, whose expressions were regulated by bile acids. Real-time PCR showed that the expression of POMC mRNA was significantly increased in the cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. POMC-derived anorexigenic peptide α-MSH increased significantly in GT1-7 cells after treatment with 10 μmol/L tLCA or CDCA for 24 h. Treatment of the cells with tLCA or CDCA significantly increased the expressions of intracellular signaling proteins including p-STAT3, p-AKT and SOCS3. CONCLUSIONS Mouse hypothalamic GT1-7 cells express bile acid receptors TGR5 and FXR. Bile acids tLCA or CDCA can promote the expression of POMC mRNA and increase the production of the anorexigenic peptide α-MSH. The intracellular signaling proteins p-AKT, p-STAT3 and SOCS3 are likely involved in bile acid-induced anorexigenic peptide production.
Animals ; Cell Line ; Chenodeoxycholic Acid ; pharmacology ; Gene Expression Regulation ; drug effects ; Hypothalamus ; cytology ; Mice ; Neuropeptides ; genetics ; metabolism ; Pro-Opiomelanocortin ; genetics ; RNA, Messenger ; genetics ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; drug effects ; Suppressor of Cytokine Signaling 3 Protein ; metabolism ; Taurolithocholic Acid ; pharmacology ; alpha-MSH ; genetics