Cardiac energy depletion in a rat model of polycystic ovarian syndrome is reversed by acetate and associated with inhibitory effect of HDAC2/mTOR

Asprosin modulates female reproductive functions in teleosts: An in vitro study in Channa punctata

Asprosin regulates various aspects of physiology in mammals including reproduction. It is reported to profoundly affect both male and female reproductive functions including gametogenesis and steroidogenesis. Asprosin is the cleaved product of a profibrillin protein encoded by the fbn1 gene. For the first time in non-mammalian vertebrates, our group demonstrated the ubiquitous expression of fbn1 and characterized asprosin protein in silico in teleost Channa punctata commonly known as spotted snakehead (ss). Based on the prominent expression of the fbn1 gene and the reproductive phase-dependent temporal expression of fbn1 in the ovary of C. punctata, we hypothesized the regulatory role of asprosin in female reproduction similar to that reported in mammals. In vitro studies confirmed the effect of asprosin on the oogenesis and steroidogenesis in C. punctata. Asprosin significantly enhanced the expression of genes crucial for oogenesis such as pcna and gdf9. It also increased the transcription of gonadotropin receptors and sex steroid receptor genes. In addition to this, asprosin accentuated the expression of steroidogenic markers such as star and cyp17a1 along with 17α, 20β dihydroxy-progesterone levels. We also measured the levels of the second messenger cAMP in ovaries exposed to asprosin to explore the probability of GPCRs as asprosin receptors. However, asprosin could not alter the cAMP levels indicating that, in the ovary of teleosts, receptors other than GPCRs might be involved in transducing asprosin action. Thus, the present study in elucidates the important role of asprosin in modulating the ovarian functions in C. punctata.

Renometabolic disorder in experimental rat model of polycystic ovarian syndrome is reversed by acetate-mediated inhibition of pyruvate dehydrogenase kinase 4

BACKGROUND

Chronic Kidney disorders is a global public health problem, including in women with polycystic ovarian syndrome (PCOS), and is characterized by renal fibrosis, nephrotoxicity and glomerulonephritis, which increases the possibility of renal failure and organ transplant. Pyruvate dehydrogenase kinase 4 (PDK4) has been implicated in mitochondria dysfunction, contributing to metabolic dysregulation in different organs, including kidney. Studies have shown that short chain fatty acids, particularly acetate, alleviates metabolic alterations in experimental models. Hence, the present study investigated the therapeutic potential of acetate on renometabolic disorders associated with experimental PCOS model. The study in addition elucidates the probable involvement of PDK4 in PCOS-associated renometabolic disorders.

METHODS

Eight-week-old nulliparous female Wistar rats were randomly allotted into four groups (n = 5). Letrozole (1 mg/kg bw) was used to induce PCOS for 3 weeks. Thereafter, acetate (200 mg/kg bw) was administered for 6 weeks, uninterruptedly. Biochemical parameters from the plasma and renal tissue, as well as histology of ovaries were performed with appropriate methods.

RESULTS

Experimental PCOS rats were characterized with elevated circulating testosterone and the presence of multiple ovarian cysts. In addition, rat with PCOS also manifested insulin resistance, increased plasma urea and creatinine levels, increased renal Gamma glutamyl transferase (GGT), malondialdehyde (MDA), Nuclear factor -kappa B (NF-kB), Tumor necrosis factor -alpha (TNF-a), Transforming growth factor -beta 1 (TGF-B1), caspase-6, Histone deacetylase 2 (HDAC2), while a decrease in glucose-6 phosphate dehydrogenase (G6PD), reduced glutathione (GSH), renal nitric oxide (NO) and endothelial nitric oxide synthesis (eNOS), when compared with animals in the control group. These were associated with elevated level of PDK4 in the renal tissue. However, administration of acetate ameliorates these renal/metabolic abnormalities.

CONCLUSION

Altogether, the results from the present study suggests that acetate ameliorates renal dysfunction in PCOS via downregulation of PDK4.

The role of short-chain fatty acid in metabolic syndrome and its complications: focusing on immunity and inflammation

Metabolic syndrome (Mets) is an important contributor to morbidity and mortality in cardiovascular, liver, neurological, and reproductive diseases. Short-chain fatty acid (SCFA), an organismal energy donor, has recently been demonstrated in an increasing number of studies to be an important molecule in ameliorating immuno-inflammation, an important causative factor of Mets, and to improve lipid distribution, blood glucose, and body weight levels in animal models of Mets. This study reviews recent research advances on SCFA in Mets from an immune-inflammatory perspective, including complications dominated by chronic inflammation, as well as the fact that these findings also contribute to the understanding of the specific mechanisms by which gut flora metabolites contribute to metabolic processes in humans. This review proposes an emerging role for SCFA in the inflammatory Mets, followed by the identification of major ambiguities to further understand the anti-inflammatory potential of this substance in Mets. In addition, this study proposes novel strategies to modulate SCFA for the treatment of Mets that may help to mitigate the prognosis of Mets and its complications.

Acetate ameliorates ovarian mitochondrial dysfunction in letrozole-induced polycystic ovarian syndrome rat model by improving mitofusin-2

Androgen excess and metabolic abnormality largely contribute to the pathogenesis of polycystic ovarian syndrome (PCOS), which primarily precipitates ovarian dysfunction and infertility in reproductive-age women. Impaired mitochondrial function and epigenetic alteration have been linked to the development of PCOS. However, it is unknown whether acetate would exert a therapeutic effect on ovarian mitochondrial dysfunction in PCOS. Herein, the study hypothesized that acetate reverses ovarian mitochondrial dysfunction in experimental PCOS rat model, possibly through modulation of mitofusin-2 (MFn2). Eight-week-old female Wistar rats were randomized into four groups (n = 5). Induction of PCOS was performed by 1 mg/kg letrozole (p.o.), administered for 21 days. Thereafter, the rats were treated with acetate (200 mg/kg; p.o.) for 6 weeks. The PCOS rats demonstrated androgen excess, multiple ovarian cysts, elevated anti-mullerian hormone and leptin and decreased SHBG, adiponectin and 17-β estradiol with corresponding increase in ovarian transforming growth factor-β1. Additionally, inflammation (tumor growth factor and nuclear factor-kB), elevated caspase-6, decreased hypoxia-inducible factor-1α and elevated histone deacetylase-2 (HDAC2) were observed in the ovaries of PCOS rats, while mitochondrial abnormality with evidence of decreased adenosine triphosphate synthase and MFn2 was observed in rats with PCOS. Treatment with acetate reversed the alterations. The present results collectively suggest that acetate ameliorates ovarian mitochondrial abnormality, a beneficial effect that is accompanied by MFn2 with consequent normalization of reproductive-endocrine profile and ovarian function. Perhaps, the present data provide hope for PCOS individuals that suffer infertility.