Association of interleukin-6 gene polymorphisms and circulating levels with keloid scars in a Chinese Han population.

The aim of the present study is to explore the effect of IL-6 gene polymorphisms on the development of keloid scar (KS) in the Chinese Han population. Genotyping of IL-6 was performed by the polymerase chain reaction (PCR), followed by restriction fragment length polymorphism assays (PCR-RFLP). Serum level of IL-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results indicated that when the IL-6 -572 CC homozygote genotype was used as the reference group, the GG genotype was found to be associated with a significantly increased risk of KS (GG vs CC: OR = 2.097, 95%CI  = 1.100-3.995, P  =  0.025). When the IL-6 -572 C allele was used as the reference group, the G allele was found to be associated with significantly increased risk of KS (G vs C: OR =  1.317, 95%CI  = 1.002-1.730, P = 0.048). Furthermore, we observed a marked increase in serum IL-6 levels in KS patients with GG genotypes when compared to KS patients harboring the CC genotype. In conclusion, our results suggest that IL-6 gene polymorphism was associated with keloid scars in the southeastern Chinese Han population.

Changes in cyclic GMP level and phosphodiesterase activity during follicular development in the rat ovary.

Guanosine 3',5'-cyclic monophosphate (cGMP), as a second messenger, plays potential roles in ovarian functions. To elucidate the role of phosphodiesterase (PDE) in cGMP signaling during ovarian follicular development, the present study was conducted to investigate ovarian cGMP level and cGMP-PDE activity by radioimmunoassay (RIA) in postnatal rats, immature rats during gonadotropin-primed follicular development, ovulation and luteinization, adult rats during normal estrous cycle, and aged rats that spontaneously developed persistent estrus (PE). All four rat models were confirmed by histological examination of one ovary, and the other ovary was used for RIA. In postnatal rats, cGMP level was high at birth and decreased dramatically by Day 5, and then, it increased maximally at Day 10 and declined at Day 21. However, cGMP-PDE activity did not significantly change during Days 1 to 10, but increased significantly on Day 21. In immature female rats, cGMP level markedly decreased upon treatment with equine chorionic gonadotropin (eCG), while cGMP-PDE activity did not show any significant changes; however, ovarian cGMP level and cGMP-PDE activity increased after injection of an ovulatory dose of human chorionic gonadotropin (hCG) for induction of ovulation and luteinization. In adult rats during normal estrous cycle, cGMP level was high on proestrus and metestrus days, while cGMP-PDE activity was high on estrus day. In PE rats, ovarian cGMP level was similar to that in adult rats on estrus and diestrus days but lower than that on proestrus and metestrus days; ovarian cGMP-PDE activity was lower than that on estrus days but similar as the other estrous cycle days. In addition, there was a significant negative correlation between ovarian cGMP level and cGMP-PDE activity during normal estrous cycles in the adult rat (r = -0.7715, N = 16, P < 0.05), but not in the postnatal rat (r = -0.1055, N = 20, P > 0.05). Together, the results of our present study indicated that ovarian cGMP levels were not dependent on cGMP-PDE activity during early postnatal development, but highly dependent on cGMP-PDE activity in the adult rat. This implies that mechanisms of cGMP signaling involved in ovarian functions are stage-specific in the rat.