Grant: Operating Grant

The growth hormone-releasing hormone receptor (GHRH-R) belongs to a family of proteins termed receptors, carrying external signals into the cells. They activate messengers systems leading to biological actions. In the pituitary hormonal gland, localized at the base of the brain, activation of this very important protein target by a specific brain factor (growth hormone-releasing hormone or GHRH), leads to the production of growth hormone (GH). Its secretion into the blood allows important actions in the various part of the body, such as cell growth. It also increases lean body mass and decrease fat. My research team has made an important discovery: the kidney contains a novel GHRH-R functional protein. Our recent results, using rat, mouse, pig and human kidneys, indicate that the structure of the kidney GHRH-R protein is different from that in the pituitary, suggesting specific roles in the kidney. Our results suggest that this receptor could protect the renal cells against oxidative stress and help injured cells to recover and take back their normal functions. In our rat model, this has been observed in specific portions of the inner kidney involved in urine concentration. The general objective of the present project is therefore to use various biological approaches to determine the features of this novel GHRH-R in the kidney. We will also determine how it sends information into the cells and what type of information it sends into the cells. We will study its role in healthy rat tissues as well as in experimental models of high oxidative cellular stress. Our results will allow determining the potential of the renal GHRH-R as a new target to consider in the maintenance of kidney functions, particularly in medical conditions of increased renal oxidative stress, such as diabetes, oxygen deprivation or ischemia, antibiotic toxicity, infections, inflammation and aging.