Yin Zongzhi, Su Jingjing, Fei Jiajia, Li Tengteng, Li Dan, Cao Yunxia, Khalil Raouf A
Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, China; Anhui Province Key Laboratory of Reproductive Health and Genetics, Hefei, China.
Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
Biochem Pharmacol. 2022 Oct;204:115244. doi: 10.1016/j.bcp.2022.115244. Epub 2022 Sep 7.
Women seeking improved fertility often undergo diagnostic hysteroscopy that could cause uterine thermal injury with unclear impact on uterine contraction, embryo implantation and fertility. We tested whether uterine thermal insult adversely affects myometrium function and contraction related receptors, channels, junctional proteins and remodeling enzymes. Female Sprague-Dawley rats were anesthetized, the left uterine horn was infused with 85 ℃ hot saline (thermal Insult) and the right horn was infused with 25℃ warm saline (control) for 3 min. After 7-days recovery, uterine strips were prepared for tissue histology and measurement of contraction, and mRNA and protein levels of oxytocin receptor, progesterone (P4) receptor A (PR-A), membrane K channel TREK-1, junctional protein connexin-43 (CX-43) and matrix metalloproteinases MMP-2 and MMP-9. Uterine tissue histology showed cellular swelling and inflammatory cell infiltration immediately following thermal insult, and recovery with no difference from control 7-days later. KCl (96 mM) and oxytocin (10-10 M) caused significant contraction that was not different in thermal insult vs control uterine strips. Pretreatment with P4 (10 M) for 1 h caused marked inhibition of KCl and oxytocin contraction that was insignificantly greater in thermal vs control uterus. RT-PCR showed decreases in oxytocin receptor, PR-A, TREK-1, CX-43, MMP-2 and MMP-9 mRNA in thermal vs control uterus. Western blots showed decreases in oxytocin receptor, no change in TREK-1 and increased PRA, CX-43, MMP-2, and MMP-9 protein levels in thermal vs control uterus. To assess the impact on fertility, female rats were housed with male rats, and on gestational day 19, the litter size, pup weight and crown-rump length, and placenta weight were not different in thermal vs control uterus. Thus, after thermal insult-induced immediate inflammation and reduced heat-sensitive mRNA expression, the uterus undergoes a recovery and adaptation process involving preserved oxytocin-induced contraction, P4 inhibition and TREK-1 channels. The uterus self-healing process appears to require improved PR-A signaling, intercellular communication via CX-43 and tissue remodeling by MMP-2 and MMP-9. The uterine thermal recovery processes could be essential for maintaining fertility and future pregnancy outcome.
寻求提高生育能力的女性常常要接受诊断性宫腔镜检查，这可能会导致子宫热损伤，而其对子宫收缩、胚胎着床和生育能力的影响尚不清楚。我们测试了子宫热损伤是否会对子宫肌层功能以及与收缩相关的受体、通道、连接蛋白和重塑酶产生不利影响。将雌性斯普拉格-道利大鼠麻醉后，向其左子宫角注入85℃的热盐水（热损伤），右子宫角注入25℃的温盐水（对照），持续3分钟。恢复7天后，制备子宫条用于组织学检查以及收缩测量，并检测催产素受体、孕激素（P4）受体A（PR-A）、膜钾通道TREK-1、连接蛋白43（CX-43）以及基质金属蛋白酶MMP-2和MMP-9的mRNA和蛋白质水平。子宫组织学检查显示，热损伤后立即出现细胞肿胀和炎性细胞浸润，7天后恢复，与对照组无差异。氯化钾（96 mM）和催产素（10-10 M）引起的显著收缩在热损伤组和对照组子宫条中无差异。用P4（10 M）预处理1小时可显著抑制氯化钾和催产素引起的收缩，热损伤组子宫的抑制作用略大于对照组。逆转录聚合酶链反应（RT-PCR）显示，热损伤组子宫中催产素受体、PR-A、TREK-1、CX-43、MMP-2和MMP-9的mRNA水平低于对照组。蛋白质免疫印迹显示，热损伤组子宫中催产素受体减少，TREK-1无变化，而PR-A、CX-43、MMP-2和MMP-9的蛋白质水平升高。为了评估对生育能力的影响，将雌性大鼠与雄性大鼠合笼饲养，在妊娠第19天，热损伤组子宫和对照组子宫的窝仔数、幼仔体重、顶臀长度以及胎盘重量均无差异。因此，在热损伤引起即时炎症并降低热敏感mRNA表达后，子宫会经历一个恢复和适应过程，包括保留催产素诱导的收缩、P4抑制作用以及TREK-1通道。子宫的自我修复过程似乎需要改善PR-A信号传导、通过CX-43进行细胞间通讯以及由MMP-2和MMP-9进行组织重塑。子宫的热恢复过程对于维持生育能力和未来的妊娠结局可能至关重要。
