Thyrotropin releasing hormone (TRH) affects gene expression in pancreatic beta-cells.
Thyrotropin-releasing hormone (TRH), originally identified as a hypothalamic hormone, is expressed in the pancreas. The peptide has been shown to control glycemia, although the role of TRH in the pancreas has not yet been clarified. In quiescent INS-1 cells (rat immortalized beta-cell line), 200 nM of TRH for 24 hours significantly increased insulin levels in the culture medium and in cell extracts. In studies with gene array technology where about 60% to 75% of the 1081 genes were detected, TRH significantly stimulated multiple groups of gene expressions, including G-protein-coupled receptor and related signaling, such as insulin secretion, endoplasmic reticulum traffic mechanisms, cell-cycle regulators, protein turnover factors, DNA recombination, and growth factors. Noticeably, TRH suppressed the genes of proapoptotic Bcl-2-associated protein X, Bcl-xL/ Bcl-2-associated death promoter, and Fas. The multiple gene expressions in response to TRH in pancreatic cells suggest that the changed microenvironment brought about by TRH may influence beta-cellfunction.
Luo
LuGuang
L
The Center for Stem Cell Biology, Department of Research, Roger Williams Hospital, 825 Chalkstone Avenue, Providence, RI 02908, USA. Lluo@RWMC.org
Yano
Naohiro
N
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015152:Blotting, Northern; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology*; D006133:Growth Substances / Q000235:genetics / Q000378:metabolism; D007328:Insulin / Q000235:genetics* / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013489:Suppression, Genetic; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D051020:bcl-X Protein / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor
D018797:Cell Cycle Proteins; C491898:Fas protein, rat; D006133:Growth Substances; D007328:Insulin; D043562:Receptors, G-Protein-Coupled; D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D019014:fas Receptor; D013973:Thyrotropin-Releasing Hormone