Genetics of Hypertension- Breakthrough in Understanding

It has long been known that kidneys have been involved in regulating blood pressure, however researchers from University of Leicester’s Department of Cardiovascular Sciences has found genes that play a big role in the process. The two genes are messenger RNAs (mRNA)  and micro RNAs (miRNA) which causes hypertension. Also, miRNA controls the expression of the hormone renin. Renin is one the biggest contributors to blood pressure regulation. They found out via study of 15 males with hypertension and 7 males with normal blood pressure. They analyzed and compared their genes mRNAs and miRNAs that are in the medulla. Messenger RNA is a single strand molecule that copies all the genetic information from DNA to mRNA strands to help make proteins. The process of converting mRNA to proteins is called miRNA. When compared they were able to tell which genes were playing a role in hypertension. I felt this article a bit confusing cause i understand how miRNA has a hormone called renin which has a big contribution in regulation blood pressure but how does mRNA play a role in this? I mean yes it copies material from DNA but what part of RNA really is controlling the blood pressure....however they found something to help people with hypertension and soon will figure out treatments.