Relaxin Receptor Variants May Play Role in Parturition
Truncated versions of relaxin receptor interfere with function of full-length receptor
FRIDAY, Dec. 28 (HealthDay News) -- Three splice variants of the relaxin receptor that are differentially expressed in fetal membranes during the peripartum period and which may have functional significance in parturition, have been identified by researchers, according to an article published online Dec. 13 in Endocrinology.
Andras Kern, Ph.D., of the University of Hawaii in Honolulu, and colleagues describe three novel splice variants of the relaxin receptor mRNA and quantified their levels in fetal membranes before and after spontaneous labor. The researchers transfected the splice variants proteins into HEK293 cells to test their function.
The splice variants were shown to be truncated versions of the full-length relaxin receptor. Expression of the splice variants was higher in the chorion and decidua prior to the onset of spontaneous labor, compared to after the onset. The splice variants exerted dominant negative effects on the wild-type relaxin receptor by physically interacting with the receptor, resulting in sequestration of the membrane within cells and blockage of normal dose-dependent accumulation of cAMP following exposure to relaxin.
The authors postulate that expression of the splice variants may have functional significance during the peripartum period. The observed splice variants "inhibition of the function of the full-length [relaxin] receptor would result in dampening of tissue responsiveness to decidual relaxin over this period of rapid local tissue changes required for successful parturition."