Gene Knockout and Metabolome Analysis of Carnitine/Organic Cation Transporter OCTN1

金沢大学医薬保健研究域薬学系Purpose: Solute carrier OCTN1 (SLC22A4) is an orphan transporter, the physiologically important substrate of which is still unidentified. The aim of the present study was to examine physiological roles of OCTN1. Methods: We first constructed octn1 gene knockout (octn1-/-) mice. Metabolome analysis was then performed to identify substrates in vivo. The possible association of the substrate identified with diseased conditions was further examined. Results: The metabolome analysis of blood and several organs indicated complete deficiency of a naturally occurring potent antioxidant ergothioneine in octn1-/- mice among 112 metabolites examined. Pharmacokinetic analyses after oral administration revealed the highest distribution to small intestines and extensive renal reabsorption of [3H]ergothioneine, both of which were much reduced in octn1-/- mice. The octn1-/- mice exhibited greater susceptibility to intestinal inflammation under the ischemia and reperfusion model. The blood ergothioneine concentration was also much reduced in Japanese patients with Crohn\u27s disease, compared with healthy volunteers and patients with another inflammatory bowel disease, ulcerative colitis. Conclusions: These results indicate that OCTN1 plays a pivotal role for maintenance of systemic and intestinal exposure of ergothioneine, which could be important for protective effects against intestinal tissue injuries, providing a possible diagnostic tool to distinguish the inflammatory bowel diseases. © 2010 Springer Science+Business Media, LLC

Pregnancy outcomes after hysteroscopic surgery in women with cesarean scar syndrome.

Cesarean scar defect often causes postmenstrual abnormal uterine bleeding, dysmenorrhea, chronic pelvic pain, and infertility, which are collectively known as cesarean scar syndrome (CSS). Several studies have reported that hysteroscopic surgery can restore fertility in women with CSS. The study aimed to identify factors that influence subsequent pregnancy following hysteroscopic surgery. Therefore, we studied 38 women with secondary infertility due to CSS who underwent hysteroscopic surgery at Shiga University of Medical Hospital between July 2014 and July 2019. Our hysteroscopic procedure included inferior edge resection and superficial cauterization of the cesarean scar defect under laparoscopic guidance. Patients were followed up for 3 to 40 months after surgery. Surgery was successful in all cases and no complications were observed. Twenty-seven patients (71%) became pregnant (pregnant group), while 11 (29%) did not (non-pregnant group). Baseline characteristics of age, body mass index, gravidity, parity, previous cesarean section, presence of endometriosis, retroflex uterus, and preoperative residual myometrial thickness were not significantly different between the groups. However, the median residual myometrium thickness was significantly higher after surgery than before surgery in the pregnant group (1.9 [1.1-3.6] vs 4.9 [3.4-6.6] mm, P<0.0001), whereas this difference was not significant in the non-pregnant group. Of those who became pregnant, 85% conceived within 2 years of surgery. Although three pregnancies resulted in abortion and one is ongoing at the time of writing, 23 pregnancies resulted in healthy babies at 35-38 gestational weeks by scheduled cesarean sections with no obstetrical complications due to hysteroscopic surgery. The average birth weight was 3,076 g. Our findings support that hysteroscopic surgery is a safe and effective treatment for secondary infertility due to CSS. The thickness of the residual myometrium may be a key factor that influences subsequent pregnancy in women with CSS