Constitutive activity of the cation channel TRPM8 regulates the function and differentiation of human monocytes

This study investigated the impact of TRPM8 activity on human monocyte differentiation and function. CD14+ peripheral blood monocytes were isolated from healthy volunteers and differentiated into macrophages using M-CSF, in the presence or absence of 10µM AMTB (TRPM8 antagonist). RNA seq was performed on CD14+ monocytes and macrophages differentiated in vehicle(Mo-M-DMSO) or AMTB (Mo-M-AMTB). To assess the transcriptional changes that normally occur in monocyte to macrophage differentiaiton we compared the Mo-M-DMSO and CD14+ monocyte samples. 3109 genes were significantly down-regulated and 3403 up-regulated in Mo-M-DMSO samples compared to CD14+ monocytes. To investigate the impact of AMTB upon macrophage differentiation we compared the Mo-M-DMSO and Mo-M-AMTB. 556 genes were significantly lower and 421 genes were significantly higher in Mo-M-AMTB samples compared to Mo-M-DMSO samples. 331 out of the 556 genes lower in Mo-M-AMTB samples were genes that were normally up-regulated during differentiaiton and 253 out of the 421 genes higher in the Mo-M-AMTB samples were genes that were normally down-regulated during differentiation indicating that AMTB predominantly acts to inhibit aspects of the differentiation programme. Overall design: Peripheral blood CD14+ monocytes from 5 healthy donors were differentiated into macrophages (Mo-M) by 6 days culture with M-CSF, in the presence of 10µM AMTB or vehicle (DMSO). PolyA+ RNA seq was performed on CD14+ monocytes, Mo-M-DMSO and Mo-M-AMTB samples.