Epigenetic blockage of transient receptor potential melastatin-subfamily member 7 (Trpm7) gene expression in Carotid body area attenuated obesity-induced Hypertension

RATIONALE: Obesity is a major cause hypertension. We have previously shown that in diet induced obese (DIO) mice leptin induces hypertension acting in the carotid bodies (CB) via the leptin-leptin receptor LEPR b – transient receptor potential melastatin 7 (TRPM7) pathway. DIO mice have high levels of Lepr b and Trpm7 gene expression in CB, and pharmacological inhibition and gene knockdown of LEPR b and TRPM7 in CB treat DIO-induced hypertension. Furthermore, we have demonstrated that leptin increases Trpm7 expression in the carotid body type I glomus cells via epigenetic mechanisms demethylating the Trpm7 promoter. Leptin binding to LEPR b activates gene transcription via STAT3 phosphorylation. We hypothesize that leptin demethylates the Trpm7 promoter at the pSTAT3 site and that methylation of this region using specific methylated oligonucleotides in vivo will decrease CB Trpm7 gene expression and BP in DIO mice. Methods: We performed in silico analysis of the Trpm7 promoter to identify putative pSTAT3 binding site(s) and used PC-12 cell culture, which are phenotypically similar to the CB type I cells, to determine if leptin regulates the Trpm7 promoter methylation at the pSTAT3 site. Next, we compared Trpm7 promoter methylation in C57BL/6J DIO male mice (n=4) and lean male mice (n=5). Finally, we generated methylated oligonucleotides complimentary to the STAT3 binding site of the Trpm7 promoter and examined the effect of these oligonucleotides on BP. DIO male mice (n = 10) were implanted with telemetry in the left femoral artery for continuous BP monitoring. BP measurements were performed at baseline and, 3-4 days after oligonucleotides application to the CB area. Results: I n silico analysis of the Trpm7 promoter showed that it contains putative binding sites for the transcription STAT3 and revealed CG dinucleotides (CpGs) where DNA methylation occurs. Leptin demethylated the STAT3 binding site of the Trpm7 promoter in PC-12 cells. DIO mice showed high levels of CB Trpm7 gene expression and low levels of promoter methylation at the STAT3 binding site compared to lean mice. DIO increased mean arterial pressure by 11.4 mm Hg during the day ( p<0.0 001 ) and by 7.1 mm Hg at night ( p <0.001 ) compared to the lean mice. CB administration of the methylated oligonucleotide specific for the STAT3 binding site of the Trpm7 promoter attenuated obesity-induced hypertension ( p<0.01 ) during the day, when animals were predominantly asleep, decreasing mean arterial pressure by 4.2 mmHg. Conclusion: Our study has shown that epigenetic blockage of the Trpm7 promoter in the CB attenuated obesity-induced hypertension. NIH R01 HL1331000, HL128970 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.