Upregulated microRNA let-7a accelerates apoptosis and inhibits proliferation in uterine junctional zone smooth muscle cells in adenomyosis under conditions of a normal activated hippo-YAP1 axis

Abstract

Background Let-7a is a small non-coding RNA that has been found to take part in cell proliferation and apoptosis. The hippo-YAP1 axis, known as a tumour suppressor pathway, also plays an important role in cell proliferation and apoptosis. YAP1, TAZ, and phospho-YAP1 play key roles in actions of the hippo-YAP1 axis. Adenomyosis (ADS) is a proliferative disease leading to a large uterus in patients with prolonged illness. Abnormal proliferation of smooth muscle cells (SMCs) in the uterine endometrial-myometrial junctional zone (JZ) is an important reason for developing ADS. This study aimed to explore the expression levels of let-7a and components of the hippo-YAP1 axis in SMCs in the uterine endometrial-myometrial JZ in ADS and to explore the roles of let-7a and the hippo-YAP1 axis of JZ SMC proliferation and apoptosis in ADS. Methods We collected JZ tissues for the primary culture of SMCs from 25 women diagnosed with ADS and 27 women without ADS. We used quantitative real-time polymerase chain reaction and western blotting to measure the mRNA and protein expression levels of let-7a, YAP1, TAZ, and phospho-YAP1 in ADS JZ SMCs. A CCK-8 assay and flow cytometry analysis of apoptosis were utilized to test the proliferation and apoptosis of JZ SMCs. The let-7a overexpression lentiviral vector GV280 was used to increase the expression level of let-7a. We added verteporfin to block the phosphorylation of components of the hippo-YAP1 axis. Results We found that the let-7a level was decreased, while the YAP1 and TAZ levels were increased in ADS JZ SMCs. Upregulated let-7a affected the expression levels of components of the hippo-YAP1 axis, accelerated apoptosis, and inhibited proliferation in JZ SMCs. Furthermore, accumulated YAP1 led to increasing proliferation of JZ SMCs after verteporfin treatment to block the phosphorylation of components of the hippo-YAP1 axis. If components of the hippo-YAP1 axis were unphosphorylated, upregulated let-7a could not inhibit the proliferation of ADS JZ SMCs. Upregulated let-7a could not activate the hippo-YAP1 axis in verteporfin treatment. Conclusions Our findings suggest that the let-7a and hippo-YAP1 axis may act as important regulators of JZ SMCs proliferation, and upregulated let-7a may be an effective method to treat ADS.

RNA-seq reveals co-dysregulated circular RNAs in the adenomyosis eutopic endometrium and endometrial–myometrial interface

“…These biological processes illustrate the altered proliferation and invasive capacity of both eutopic endometrial cells and EMI smooth muscle cells in adenomyosis. Meanwhile, targeted genes in the network were involved in various important signaling pathways, such as the MAPK signaling pathway, PI3K-Akt signaling pathway, Ras signaling pathway and Hippo signaling pathway, according to the KEGG analysis, which have also been shown to be involved in adenomyosis [47][48][49][50]. The results suggest that eutopic endometrium and EMI smooth muscle co-expression of circRNAs alters cellular activity and influences the development of uterine adenomyosis by regulating these important signaling pathways.…”

Exploration the global single-cell ecological landscape of adenomyosis-related cell clusters by single-cell RNA sequencing

“…Abnormal proliferation of SMC in the endometrium-myometrial junction area is an important cause of AM ( Huang et al, 2021 ), and the emergence of AM causes hyperplasia and hypertrophy of the surrounding SMC ( Zhai et al, 2020 ). Compared to the SMC in the normal uterus, the uterine SMC has hypertrophy and ultrastructural changes, which may have contractility effects on the myometrium ( Mehasseb et al, 2010 ).…”

Pathogenesis of Human Adenomyosis: Current Understanding and Its Association with Infertility

“…A recent report found that Let-7A level was decreased, while the YAP1 level was increased, in uterine junctional zone SMCs in adenomyosis. Up-regulated Let-7A affected the expression levels of the components of the hippo-YAP1 axis, accelerated apoptosis and inhibited proliferation of JZ SMCs [ 144 ]. These findings suggest that the Let-7A and hippo-YAP1 axis may act as important regulators in the proliferation of JZ SMCs and occurrence of adenomyosis.…”