Genomic and Non-Genomic Estrogen Effects on the Spinal Nr2b-Related Uterus-Colon Crosstalk in Rats

Epidemiological studies have demonstrated comorbidity of inflammatory pain-associated gynecological problems and irritable bowel syndrome (IBS). In this project, we will try to investigate the uterus-colon crosstalk, a form cross-organ sensitization between pelvic viscera that possibly underlies the comorbidity of obstetrical, gynecological, urological and gastrointestinal dysfunctions in the pelvic area. In the first year, we will try to establish a stable animal model to evaluate the crosstalk between the uterus and the colon. Additionally, the role of uterus TRPA1 activation and spinal NMDAR NR2B subunit phosphorylation in the uterus-colon crosstalk will also elucidated. For the obstetrical and gynecological pain is pronouncedly affected by estrogen. In year 2 and 3, we will try to investigate the genomic and non-genomic effects of estrogen on the uterus-colon crosstalk. In year 2, the degree of uterus-colon cross will be compared and contrast first in animals received sham operation, ovariectomy, and ovariectomy with daily estrogen supplement in 20-30 day after surgery. Next, the crosstalk between the uterus and colon will be also measured in animals of proestrus and metestrus phase of estrus cycle. Also, the expression of NR2B in the lumbosacral dorsal horn will be evaluated in these groups using Western blotting analysis to elucidate its role in the genomic estrogen effect. In year 3, the uterus-colon crosstalk will be evaluated in ovariectomized rats at 0.5, 1, 3, 6 hours after subcutaneous estrogen or vehicle solution administration to test the non-genomic estrogen modulation. Moreover, the participation of estrogen receptor/pAkt/PSD-95/pNR2B cascade in the lumbosacral dorsal horn horn neurons will be elucidated using pharmacological in accompanied with Western blotting analysis. Finally, after the experiments in the first 3 years has demonstrated a crucial role of spinal NR2B subunit in the uterus-colon crosstalk, we will evaluate the uterus-colon crosstalk after genetic knockdown of the NR2B in the lumbosacral dorsal horn using small interfering RNA in the study of year 4. Through these studies, we hope could 1. establish a experimental model for investigating comobidity of gynecological and gastrointestinal pain. 2. provide a possible pharmacological strategy for the treatment of IBS caused by gynecological causes.