Investigation of melatonin receptor gene and protein expression in human peripheral blood lymphocytes / 中国病理生理杂志

ABSTRACT

AIM: To investigate the melatonin receptor (MR) gene and protein expression in the human peripheral blood lymphocytes. METHODS: Total RNA of human peripheral lymphocytes was isolated by single step method of acid guanidinium-thiocyanate-phenol-chloform, mt 1 and MT 2 mRNA were determined by the reverse transcription-polymerase chain reaction(RT-PCR). Immunohistochemistry was applied to identify and localize mt 1 and MT 2 protein. RESULTS: 1 1 kb mt 1 mRNA was detected by Northern blot, but 1 1 kb MT 2 mRNA was not detected. The mt 1 cDNA fragment of the expected size of 370 bp was determined and the MT 2 cDNA fragment of the expected size of 320 bp was not determined by RT-PCR. Sequencing result indicated that the positive product coincided with the cDNA of human mt 1. The mt 1 protein was observed by immunohistochemistry. These buffy positive granules were scattered with some areas stronger than the others, and primarily located in cytoplasm and membrane, with rare location in nucleus; meanwhile the MT 2 protein was not observed. CONCLUSION: These results demonstrated the mt 1 mRNA and protein expression in human peripheral leukocytes. It is indicated that melatonin has directly immune-regulative effects on peripheral lymphocytes.