MiRNAs expression profiling of rat ovaries displaying PCOS with insulin resistance

Chunren Zhang,Haixia Pan,Hongxia Ma,Zengxian Lin,Chuyi Yu,Kunyin Li

doi:10.1007/s00404-020-05730-z

Abstract

PurposeThe present study established microRNA (miRNA) expression profiles for rat ovaries displaying polycystic ovary syndrome (PCOS) with insulin resistance and explored the underlying biological functions of differentially expressed miRNAs.MethodsA PCOS with insulin resistance rat model was created by administering letrozole and a high-fat diet. Total RNA was extracted from the ovaries of PCOS with insulin resistance rats and normal rats. Three ovaries from each group were used to identify differentially expressed miRNAs by deep sequencing. A hierarchical clustering heatmap and volcano plot were used to display the pattern of differentially expressed miRNAs. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to explore the potential target genes of the differentially expressed miRNAs and identify their putative biological function. Nine of the differentially expressed miRNAs were selected for validation by Real-time Quantitative PCR (qRT-PCR).ResultsA total of 58 differentially expressed miRNAs were identified in the rat ovaries exhibiting PCOS with insulin resistance compared with control ovaries, including 23 miRNAs that were upregulated and 35 miRNAs that were downregulated. GO and KEGG pathway analyses revealed that the predicted target genes were related to metabolic processes, cellular processes, and metabolic pathways. Furthermore, qRT-PCR confirmed that miR-3585-5p and miR-30-5p were significantly upregulated and miR-146-5p was downregulated in the ovaries of PCOS with insulin resistance rats compared with the controls.ConclusionThese results indicate that differentially expressed miRNAs in rat ovaries may be involved in the pathophysiology of insulin resistance in PCOS. Our study may be beneficial in establishing miRNAs as novel diagnostic and therapeutic biomarkers for insulin resistance in PCOS.

Highlights

Polycystic ovary syndrome (PCOS), which affects 6–20% of women during reproductive age, is one of the most common endocrine and metabolic disorders [1,2,3]
hematoxylin and eosin (H&E) staining results showed that the ovary in the control group (CON) group had follicles and corpora lutea at various stages of development, a normal theca and granulosa cell layer and no ovarian cysts
Compared with the CON group, the body weight, fasting insulin (FINS) and homeostasis model assessment for insulin resistance (HOMA-IR) were significantly increased in rats from the LEHF group (Fig. 2a, b)

Summary

Introduction

Polycystic ovary syndrome (PCOS), which affects 6–20% of women during reproductive age, is one of the most common endocrine and metabolic disorders [1,2,3]. According to the Rotterdam criteria, PCOS may be diagnosed with at least two of the three following characteristics: anovulation, clinical and/or biochemical signs of hyperandrogenism and polycystic ovaries [4, 5]. PCOS is associated with infertility, insulin resistance, obesity, glucose tolerance, dyslipidemia, type 2 diabetes and increased risk for cardiovascular disease [6]. Insulin resistance and hyperandrogenism are the two main characteristic features of PCOS, and important pathogenic factors for PCOS [7]. Insulin synergizing with androgen could result in deteriorating anovulation, hyperandrogenism, hyperinsulinemia and infertility in PCOS patients. Genetic studies and familial clustering of phenotypic features have indicated that PCOS is heritable [8,9,10,11]. One potential mechanism is an epigenetic process which could yield the same phenotypic characteristics as heritable genetics [17, 18]

Methods

Results

Conclusion