Hypothalamic DNA methylation in rats with dihydrotestosterone‐induced polycystic ovary syndrome: effects of low‐frequency electro‐acupuncture

Abstract

Polycystic ovary syndrome (PCOS) is a common reproductive and endocrine disease of unknown aetiology. Recently, epigenetic studies focusing on DNA methylation in PCOS have received much attention, but the mechanisms are still unclear. In the present study, we used the 5α-dihydrotestosterone-induced PCOS-like rat model and treated the rats with electro-acupuncture (EA). Rats were randomly divided into four groups - controls, diet-induced obesity, PCOS and PCOS+EA. We examined the reproductive, metabolic and behavioural phenotypes, validated the effect of EA, and explored the role of hypothalamic DNA methylation by analysing the methylation of global DNA and selected candidate genes. The PCOS rats presented with reproductive dysfunctions such as lack of regular oestrous cyclicity, metabolic disorders such as increased body weight and insulin resistance, and depression and anxiety-like behaviours. EA improved the reproductive functions, decreased body weight and improved experimental depressive behaviour. Furthermore, global DNA methylation and the expression of DNA methyltransferases (DNMTs) were increased in PCOS rats compared to the control group, and EA decreased the global DNA methylation and the expression of DNMT3b. In addition, pyrosequencing showed that the DNA methylation of certain CpG sites in targeted genes (Plcg1, Camk2b, Esr2 and Pgr) was increased in the PCOS group, but the DNA methylation of Camk2b and Ar was decreased after EA treatment. These results indicate that hypothalamic DNA methylation might be correlated with the development of PCOS and that EA has an effect on hypothalamic DNA methylation in PCOS rats.

Effect of electroacupuncture on the kisspeptin system in a pubertal rat model of polycystic ovary syndrome

“…EA and SA could decrease the expression of kisspeptin in the hypothalamus and ARC, which may be the rationality of decreasing LH in the EA and SA groups. A study showed that expression of DNA methyltransferases was increased and EA decreased global DNA methylation, 20 which may be associated with decreased kisspeptin mRNA in PCOS rats at puberty after treatment with EA. GnRH was observed to exist mainly in the median eminence.…”

Ovarian Innervation Coupling With Vascularity: The Role of Electro-Acupuncture in Follicular Maturation in a Rat Model of Polycystic Ovary Syndrome

“…Oral Glucose Tolerance Test (Cui et al, 2018) After fasting overnight (10-12 h), glucose levels in the tail vein blood were measured using a blood glucose meter (ACCU-CHECK Performa, Roche). One researcher securely held the animal and cleaned the tail, and another researcher prepared the blood glucose meter and took the measurement.…”

Beneficial Effects of Magnetic Fields on the Human Heart a Review of Current Advances and Proposed Mechanisms

“…Published data also shows a direct effect of acupuncture on hypothalamic DNA methylation. DNA methylation is described as one of several epigenetic (non-genetic mechanisms that cells use to control gene expression), in other words acupuncture places some genes in the "off" position (14).…”