Low dose spironolactone-mediated androgen-adiponectin modulation alleviates endocrine-metabolic disturbances in letrozole-induced PCOS

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.

Management of Hypertension in Patients With Polycystic Ovarian Syndrome: A Mini-Review

Polycystic ovarian syndrome (PCOS) is a common problem among young women. It is characterized mainly by hyperandrogenism features, such as hirsutism, menstrual problems, and anovulation. Diagnosis is based on the existence of 2 items out of, oligo-ovulation, hyperandrogenism features, and ultrasounds findings. Cardiovascular complications such as hypertension are a prevalent serious condition in these patients which is mainly predisposed by the high levels of androgens, and insulin resistance. High blood pressure should be controlled well to prevent the progression of other serious conditions. Various antihypertensive drugs could be prescribed. However, in selecting an antihypertensive medication, other therapeutic properties of the drug should also be considered. Up to now, many clinicians do not differ between PCOS patients with hypertension and other hypertensive patients. However, being aware of the potential effects of each hypertension drug could help to choose better options for the patient. Here is a brief review of how each antihypertensive drug could affect PCOS women and if they cause any improvement in the disorder progression.

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

In addition to the clinical manifestation of polycystic ovarian syndrome (PCOS), life-threatening diseases, especially hypertension and cardiovascular disease (CVD) are emerging critical complications of PCOS. Changes in cardiac energy remains an independent risk factor of CVD. Histone deacetylase (HDAC) inhibitors, including acetate has received attention for its beneficial role in energy regulation. Herein we hypothesized that acetate improves cardiac energy homeostasis in experimentally induced PCOS. Female Wistar rats (8-week-old) were divided into groups. To induce PCOS, 1 mg/kg of letrozole was given for 21 days. After confirmation of PCOS, acetate (200 mg/kg) was administered for 6 weeks. Rats with PCOS showed multiple ovarian cysts with androgen excess and decreased SHBG. The rats also manifested impaired glucose tolerance/hyperinsulinemia and hypertriglyceridemia. Increased systemic oxidative stress (malondialdehyde)/inflammatory (NF-kB/SDF-1) markers and nitric oxide deficiency (NO/eNOS) were observed. Though, the body weight was increased without affecting the cardiac mass index of PCOS rats. Nevertheless, there was an increase in cardiac triglyceride and oxidative stress/inflammatory markers with consequent cardiac injury, revealed by decreased levels of SIRT-1/HIF-1α and increased levels of CTGF/TGFβ-1 and plasma troponin T. These led to cardiac ATP depletion with increased AMP and AMP/ATP ratio. These alterations were accompanied by elevated levels of mTOR and HDAC2, which were reversed when treated with acetate. The present results interestingly suggest that HDAC2 inhibition by acetate reversed cardiac energy depletion and attendant cardiomorbidities in experimental PCOS model. A beneficial effect that is accompanied by suppressed expression of mTOR.

Alleviation of adipose-hepatic glycolipid dysregulation by acetate in experimental PCOS model is associated with NF-κB/NLRP3 repression

This study hypothesized that acetate breaks the vicious cycle driving adipose-hepatic metabolic dysregulation in a rat model of polycystic ovarian syndrome (PCOS), possibly by suppression of nuclear factor-kappaB (NF-κB)/NOD-like receptor protein 3 (NLRP3) inflammasome. Female Wistar rats (8-week-old) were randomly allocated into four groups of n =6/group, which received vehicle, sodium acetate (200 mg), letrozole (1 mg/kg), and letrozole plus sodium acetate, respectively. The animals were treated by oral gavage, once daily for a period of 21 days. The PCOS animals were insulin-resistant, hyperandrogenic, and hypoestrogenic with decreased sex-hormone binding globulin. In addition, the hepatic tissue had increased lipid profile and decreased glycogen synthesis, while the adipose tissue showed decreased lipid profile with elevated glycogen synthesis. Besides, the results also showed increased malondialdehyde, γ-glutamyl transferase, lactate dehydrogenase, and inflammatory mediators with corresponding decrease in antioxidant defense in the hepatic and adipose tissues. Immunohistochemical evaluation also demonstrated severe expression with Bcl2-associated X protein/NLRP3 antibodies. Nonetheless, concomitant acetate supplementation attenuated these derangements. The present data collectively suggest that acetate ameliorates adipose-hepatic glycolipid dysregulation in experimental PCOS model by attenuating androgen excess and NF-κB/NLRP3 immunoreactivity.

Modulation of GABA by sodium butyrate ameliorates hypothalamic inflammation in experimental model of PCOS

Polycystic ovarian syndrome (PCOS) is a known endocrine disorder that has affected many women of childbearing age, and is accompanied by various neurodegenerative conditions. Hence, this study investigates the impact of butyrate in reversing hypothalamic-related disorder, possibly through γ aminobutyric acid (GABA) in a rat model of PCOS. Eight-week-old female Wistar rats were allotted into four groups (n = 5), which include control, butyrate, letrozole, and letrozole + butyrate groups. PCOS was induced by administering 1 mg/kg of letrozole (oral gavage) for 21 days. After confirmation of PCOS, 200 mg/kg of butyrate (oral gavage) was administered for 6 weeks. Rats with PCOS were characterized by elevated levels of plasma insulin and testosterone. Increases in plasma and hypothalamic triglyceride levels, inflammatory biomarker (SDF-1), apoptotic marker (caspase-6), and decreased plasma GnRH were observed. Additionally, a decrease in hypothalamic GABA was revealed. Nevertheless, the administration of butyrate attenuated these alterations. The present study suggests that butyrate ameliorates hypothalamic inflammation in an experimental model of PCOS, a beneficial effect that is accompanied by enhanced GABA production.

Butyrate alleviates renal inflammation and fibrosis in a rat model of polycystic ovarian syndrome by suppression of SDF-1

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a multifactorial condition with metabolic-related complications, such as diabetic nephropathy and chronic renal disorder, which are the leading cause of renal transplant globally. Protective effects of histone deacetylase (HDAC) inhibitors (HDACi) have been documented in metabolic-linked pathologies. Nonetheless, the current study investigated the restorative role of HDACi, butyrate in experimental PCOS-induced renal disorder.

MATERIALS AND METHODS

Female Wistar rats (8-week-old) were divided into groups; control, butyrate-treated, letrozole and letrozole + butyrate-treated groups. To induce PCOS, 1 mg/kg of letrozole was given (oral gavage) for 21 days. After confirmation of PCOS, 200 mg/kg of butyrate (oral gavage) was administered for 6 weeks.

RESULTS

Rats with PCOS revealed disruption in glucose homeostasis (hyperinsulinemia and impaired glucose tolerance and insulin resistance) and presented with the phenotypes of PCOS (hyperandrogenism, multiple ovarian cysts and elevated LH/FSH ratio). Increased plasma and renal triglycerides and inflammatory (TNF-α/SDF-1/NF-κB) markers were observed with elevated levels of TGFβ-1, renal lipid peroxidation and redox imbalance (GGT, GSH, HIF-1α). Interestingly, animals with PCOS reported increased body weight as well as renal mass. Whereas, heightened levels of plasma urea, creatinine and creatine kinase indicating renal dysfunction, characterized by renal apoptosis (Caspase-6) and increased HDAC2 levels. Notwithstanding, administration of butyrate averted the alterations.

CONCLUSION

The present investigation demonstrates that PCOS declines renal function, which is accompanied by renal inflammation, apoptosis and fibrosis. The study further suggests that butyrate, an HDAC2i restores renal function by suppressing renal SDF-1 with subsequent attenuation of renal inflammation, apoptosis and fibrosis.

Effect of spironolactone on pharmacological treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) was recently renamed to metabolic (dysfunction)-associated fatty liver disease (MAFLD) to better characterize its pathogenic origin. NAFLD represents, at least in western societies, a potential epidemic with raising prevalence. Its multifactorial pathogenesis is partially unraveled and till now there is no approved pharmacotherapy for NAFLD. A plethora of various choices are investigated in clinical trials, targeting an arsenal of different pathways and molecules. Since the mineralocorticoid receptor (MR) and renin-angiotensin-aldosterone system (RAAS) appear to be implicated in NAFLD, within this concise review, we focus on a rather classical and inexpensive pharmacological agent, spironolactone. We present the current lines of evidence of MR and RAAS-related preclinical models and human trials reporting an association with NAFLD. In conclusion, evidence about spironolactone of RAAS is commented, as potential future pharmacological management of NAFLD.

Trends in metabolic dysfunction in polycystic ovary syndrome: a bibliometric analysis

Polycystic ovary syndrome (PCOS) is a very common chronic disease and causes reproductive disorders in women of childbearing age worldwide. The cause of metabolic dysfunction in PCOS is unknown, and there is a lack of systematic bibliometric analysis for this disease. This study included 3,972 articles on metabolic dysfunction in PCOS published from 2012 to 2021. We applied the VOSviewer and the CiteSpace scientometric analysis software to analyze the data regarding the publication of the articles, countries, authors, institutions, scientific categories, cited journals, and keywords. Through this analysis, we determined the research efforts and their developing trends and anticipated the progress in understanding PCOS-related metabolic dysfunction.

Low-dose spironolactone combats dyslipidemia and hepatic inflammation by modulating PCSK9 in rat model of polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder among women and it is associated with overt metabolic derangement. Circulating lipids are regulated by proprotein convertase subtilisin/kexin type 9 (PCSK9) which blocks low density lipoprotein (LDL) receptors especially in the liver. The liver is highly vulnerable in dyslipidemia as lipid accumulation leads to progression of non-alcoholic fatty liver disease (NAFLD). An array of scientific endeavours hold that low-dose spironolactone (LDS) is beneficial as intervention for PCOS traits, but this claim is yet to be fully elucidated. The aim of this study was to investigate the effect of LDS on dyslipidemia and hepatic inflammation in rats with letrozole (LET)-induced PCOS and to assess the possible involvement of PCSK9 in these effects. Eighteen female Wistar rats were randomly assigned into 3 groups. The control group received vehicle (distilled water; p.o.), LET-treated group received letrozole (1 mg/kg; p.o.), LET+LDS-treated group received LET plus LDS (0.25 mg/kg, p.o.) for 21 days. Exposure to LET increased body and hepatic weights, plasma and hepatic total cholesterol (TC), TC/HDL, LDL, interleukin-6, MDA, PCSK9, ovarian degenerated follicles and hepatic NLRP3 intensity, reduced GSH and normal ovarian follicles. Interestingly, LDS averted dyslipidemia, NLRP3-dependent hepatic inflammation and ovarian PCOS traits. It is evident herein that LDS ameliorates PCOS traits and combats dyslipidemia and hepatic inflammation in PCOS by a PCSK9-dependent mechanism.

Mesenchymal-Stem Cell-Derived Conditioned Media Versus Exosomes in the Treatment of Rat Model of Polycystic Ovary: An Attempt to Understand the Underlying Mechanisms (Biochemical and Histological Study)

Polycystic ovary syndrome (PCOS) is one of the most common endocrine and reproductive disorders throughout female reproductive age. Cell free therapy [conditioned media (CM) & exosomes (EXO)] is a promising approach in regenerative medicine. This study aimed to compare between the therapeutic effects of stem cell-derived CM and exosomes on induced animal model of polycystic ovary. Polycystic ovary (PCO) was induced in female rats (3-4 weeks old, weighing 70-80 g) by letrozole with a dose of 1 mg/kg/day dissolved in carboxymethylcellulose 1% orally once daily for 5 weeks. Animals were divided into four groups: control group, PCO group, EXO-treated group, and CM-treated group. Serum levels of testosterone hormone, leutinizing hormone, follicle stimulatimg hormone, and insulin hormone were estimated. Immunohistochemistry using anti-P53, anti-AMP-dependent protein kinase antibodies were done. Six rats/group were used for matting with adult male rats for testing fertility. The results showed that CM had significant superior therapeutic effects on exosomes in restoring the normal histological architecture of the ovary and fertility. In summary, cell free treatment is a safe approach for tissue regeneration. Stem cell-derived CM was more effective than exosomes in restoring normal histological structure of the ovaries and fertility in animal models of polycystic ovary.

Acetate circumvents impaired metabolic switch in skeletal muscle of letrozole-induced PCOS rat model by suppression of PDK4/NLRP3

OBJECTIVES

Endocrine disorders in women of childbearing age, including polycystic ovarian syndrome (PCOS), have been linked to skeletal muscle insulin resistance with multiple post-receptor intracellular defects, disrupting metabolic flexibility. Short-chain fatty acids, such as acetate have been suggested as a metabolic modulator. However, the effects of acetate on aberrant metabolic switch in skeletal muscle of individuals with PCOS are unknown. This study therefore hypothesized that acetate would circumvent impaired metabolic switch in the skeletal muscle of a letrozole-induced PCOS rat model, probably by suppression of PDK4/NLRP3.

METHODS

Eight-wk-old female Wistar rats were assigned into three groups (n = 6), which received vehicle, letrozole (1 mg/kg), and letrozole plus acetate (200 mg/kg), respectively. The administrations were done by oral gavage for 21 d. .

RESULTS

Animals with PCOS had insulin resistance, increased testosterone, and leptin, as well as decreased adiponectin level. Additionally, the skeletal muscle was also characterized with increased lipid deposition, malondialdehyde, inflammatory mediators (nuclear factor-κB and tumor necrosis factor-α), lactate dehydrogenase, lactate/pyruvate ratio, HDAC and PDK 4 with corresponding decrease in glycogen synthesis, glutathione and NrF2. Besides, immunohistochemical evaluation showed severe expression of inflammasome and apoptosis in PCOS animals. Nonetheless, supplementation with acetate significantly attenuated these perturbations.

CONCLUSIONS

The present results demonstrate aberrant metabolic switch in the skeletal muscle of PCOS animals, which is accompanied by excessive inflammation, oxidative stress and elevated levels of histone deacetylase and PDK4. The results suggested that histone deacetylase inhibitor, acetate circumvents impaired metabolic switch in the skeletal muscle of PCOS rats by suppression of PDK4/NLRP3 inflammasome.

Protective Role of Acetate Against Depressive-Like Behaviour Associated with Letrozole-Induced PCOS Rat Model: Involvement of HDAC2 and DNA Methylation

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age. PCOS has been demonstrated to induce depressive-like behaviour. Epigenetic alterations such as histone deacetylation (HDAC) and DNA methylation have been suggested in major depression. However, their effects with respect to neuroinflammation are not clear. This study therefore investigated the pathogenic involvement of epigenetic changes in PCOS-associated depression and the protective role of HDACi, especially acetate. Virgin female Wistar rats (140 ± 10 g) were assigned into four groups: the groups received vehicle (control), acetate (200 mg/kg), letrozole (1 mg/kg) and letrozole plus acetate, respectively. The administrations were done concomitantly by oral gavage for 21 days. Treatment with letrozole caused hyperandrogenism, hypoestrogenism, hyperinsulinemia and multiple ovarian cysts/degenerated follicles. In addition, these animals showed depressive-like behaviours and increased expression of HDAC2 and DNA methyltransferase in PFC and hippocampal tissues. Biochemical analyses showed elevated levels of NF-κB, malondialdehyde and acetylcholine (ACH) with glutathione depletion in PFC and hippocampus as well as elevated plasma malondialdehyde and impaired anti-oxidant system in letrozole-treated animals. Histological analysis of PFC and hippocampus showed neurodegeneration in letrozole-treated animals compared with control. However, these alterations were attenuated when treated with acetate. The study demonstrates that PCOS-associated depression is characterised by neuroinflammation and elevated ACH levels, accompanied by increased expression of HDAC2/DNA methyltransferase in PFC and hippocampus. Besides, the study suggests that acetate protects against PCOS-associated depression through suppression of prefrontal and hippocampal DNA methylation and prefrontal but not hippocampal HDAC2 expression.

Acetate restores hypothalamic-adipose kisspeptin status in a rat model of PCOS by suppression of NLRP3 immunoreactivity

PURPOSE

Polycystic ovary syndrome (PCOS) is a complex reproductive event that is delineated by endocrine/metabolic disorders. Alteration of kisspeptin status in the hypothalamus and adipose tissue is critical to increased endocrine/metabolic derangements in PCOS individuals, aggravating the clinical manifestation of PCOS and its complications. Short chain fatty acids (SCFAs) are crucial modulators of metabolic homeostasis. However, the role of SCFAs, particularly acetate on hypothalamic-adipose kisspeptin status (HAKS) in PCOS model is unknown. The present study hypothesized acetate as a key player in restoration of deranged HAKS, associated with experimental PCOS model.

METHODS

Three groups (n = 6/group) of female Wistar rats (120-150 g) were used. The groups were treated (po) for 21 days with vehicle, letrozole (1 mg/kg) with/without acetate (200 mg/kg) respectively.

RESULTS

Letrozole-treated animals had impaired glucose homeostasis, elevated testosterone, leptin and LH/FSH ratio and decreased GnRH and adiponectin with ovarian tissues revealing degenerated follicles and disrupted morphology. These animals also showed increased concentration of hypothalamic triglyceride (TG)/total cholesterol (TC), free fatty acid (FFA), and decreased concentration of TG/TC/FFA in visceral adipose tissue (VAT) with an increase in hypothalamic and VAT malondialdehyde, NF-κB/TNF-α and decreased glutathione/G6PD and hypothalamic but not VAT kisspeptin. Immunohistochemical analysis revealed the expression of NLRP3 inflammasome in the hypothalamus and VAT and all these changes were attenuated by acetate.

CONCLUSIONS

Altogether, the present results demonstrate that PCOS is characterized with hypothalamic-adipose inflammation, associated with immunohistochemical expression of NLRP3 with significant alteration of hypothalamic but not adipose kisspeptin. The results suggest that acetate restores kisspeptin status in PCOS animals. This beneficial effect is accompanied by repressed NLRP3 immunoreactivity.

Low-dose spironolactone ameliorates adipose tissue inflammation and apoptosis in letrozole-induced PCOS rat model

BACKGROUND OF STUDY

Globally, many reproductive aged women are affected by polycystic ovarian syndrome (PCOS), which is a common endocrine and metabolic disorder that is linked with adipose dysfunction and chronic low-grade inflammation. Spironolactone (SPL), a mineralocorticoid receptor blocker has been documented as a metabolic modulator. However, its immunomodulatory effect in PCOS is unknown. Therefore, the present study hypothesized that SPL would ameliorate adipose dysfunction and inflammation in experimental PCOS animals.

MATERIALS AND METHODS

Female Wistar rats that were 8 weeks old were allocated into three groups. Group 1 received vehicle (distilled water; p.o.), group 2 received letrozole (1 mg/kg; p.o.) and group 3 received letrozole plus SPL (0.25 mg/kg, p.o.). The administration was performed once daily for 21 days.

RESULTS

The experimental PCOS animals showed insulin resistance, hyperinsulinemia and hyperandrogenism as well as oxidative stress and elevated inflammatory biomarkers (NF-kB/TNF-/IL-6) as well as a significant decrease in triglycerides, total cholesterol, free fatty acids, GSH and G6PD in the adipose tissue of PCOS animals. In addition, immunohistochemical assessment of adipose tissue showed significant expression of BAX and inflammasome, indicating apoptosis and inflammation compared to control animals. Nevertheless, administration of SPL attenuated these perturbations.

CONCLUSION

Altogether, the present study suggests that low-dose spironolactone confers protection against adipose dysfunction in experimental PCOS animals by attenuating inflammation, oxidative stress and cellular apoptosis.

Distinctions in PCOS Induced by Letrozole Vs Dehydroepiandrosterone With High-fat Diet in Mouse Model

Polycystic ovarian syndrome (PCOS) is a complex health condition associated with metabolic disturbances and infertility. Recent data suggest that the prevalence of PCOS is increasing among women globally, although the etiology of these trends is undefined. Consequently, preclinical models that better reflect the biology of PCOS are urgently needed to facilitate research that can lead to the discovery of prevention strategies or improved management. The existing animal models have several limitations as they do not reflect all the PCOS features metabolically and/or phenotypically. Therefore, there is no clear consensus on the use of appropriate animal model and selection of the most appropriate PCOS-inducing agent. To that end, we have established a Swiss albino mouse model of PCOS based on 3 weeks of daily treatment with letrozole (50 μg/day; intraperitoneal) and dehydroepiandrosterone (DHEA, 6 mg/100 g body weight; subcutaneous) in 5-week-old female mice fed on normal or high-fat diet (HFD). Mice were regularly assessed for body weight, blood glucose, and estrous cycle. Three weeks after drug administration, mice were sacrificed and assessed for blood-based metabolic parameters as well as ovarian function. Our results indicate that DHEA combined with HFD produces changes mimicking those of clinical PCOS, including elevated serum testosterone and luteinizing hormone, dyslipidemia, poor ovarian microenvironment, and development of multiple ovarian cysts, recapitulating cardinal features of PCOS. In comparison, normal diet and/or letrozole produced fewer features of PCOS. The data from the experimental models presented here can improve our understanding of PCOS, a growing concern in women's health.

Short chain fatty acid, acetate restores ovarian function in experimentally induced PCOS rat model

BACKGROUND

Polycystic ovarian syndrome (PCOS) is pathogenically characterized with hyperandrogenism and metabolic alterations, which often result in ovarian changes and infertility in women of reproductive age. Epigenetic changes have been linked to the development of PCOS. However, the involvement of epigenetic regulator, histone deacetylase (HDAC) in PCOS-driven ovarian dysfunction is not clear. Howbeit, the present study hypothesized that acetate, an HDAC inhibitor (HDACi) would protect against ovarian dysfunction in experimentally induced PCOS.

MATERIALS AND METHODS

Female Wistar rats weighing 120-150 g were randomly divided into four groups (n = 6). The groups received vehicle, sodium acetate (200 mg/kg), letrozole (1 mg/kg) and letrozole with acetate by oral gavage respectively. The administrations were done daily for 21 days.

RESULTS

The rat model of PCOS had increased body weight and ovarian weight, 1-hr postload glucose and plasma insulin, testosterone and LH/FSH ratio as well as reduced insulin sensitivity and plasma 17-β estradiol and sex hormone binding globulin. This model of PCOS in addition showed a significant increase in plasma and ovarian triglyceride, total cholesterol, TNF-α and HDAC, and ovarian malondialdehyde as well as a significant reduction in ovarian glutathione peroxidase/reduced glutathione and NrF2 with the histology of ovarian tissues showing disrupted morphology with significant increase in the number of degenerated follicles compared with control group. These alterations were however attenuated when treated with HDACi, acetate.

CONCLUSION

Altogether, the present results suggest that acetate protects ovarian function with evidence of normal growing follicles and enhanced circulating 17-β estradiol by inhibition of HDAC.

Suppression of PCSK9/NF-kB-dependent pathways by acetate ameliorates cardiac inflammation in a rat model of polycystic ovarian syndrome

AIM

Endocrinometabolic disorders in women of reproductive age, including polycystic ovarian syndrome (PCOS) has contributed to increased prevalence of cardiovascular disease (CVD) risk and its attendant complications. Acetate, the most abundant endogenously produced short chain fatty acid has been linked to metabolic health. However, the impact of acetate on CVD-driven pathologies in PCOS is unknown. The present study therefore investigated the effects of acetate on cardiometabolic abnormalities associated with PCOS in rat model, and the possible involvement of PCSK9/NF-kB-dependent pathways.

MATERIALS AND METHODS

Eight-week-old female Wistar rats were allotted into four groups (n = 6) and the groups received vehicle, acetate (200 mg/kg), letrozole (1 mg/kg) and letrozole plus acetate respectively. The administrations were done once daily by oral gavage and lasted for 21 days.

KEY FINDINGS

In letrozole-induced PCOS rats characterized with insulin resistance, glucose dysregulation, elevated plasma testosterone and decreased 17-β estradiol as well as degenerated ovarian follicles, there was a significant increase in plasma and cardiac lipid/lipoproteins, lipid peroxidation, inflammatory mediators (NF-kB and TNF-α), γ-glutamyl transferase/lactate dehydrogenase and lactate content, PCSK9 and reduction in plasma and cardiac antioxidants (glutathione peroxidase and reduced glutathione) and plasma nitric oxide synthesis (eNOS and NO) compared with the control rats. In addition, immunohistochemical assessment of cardiac tissue showed severe expression of inflammasome in letrozole-induced PCOS rats compared with the control rats. Nevertheless, supplementation with acetate significantly attenuated these alterations.

SIGNIFICANCE

The present results suggest that acetate protects against cardiac inflammation in a rat model of PCOS by suppression of PCSK9 and NF-kB-dependent mechanisms.

Repression of HDAC5 by acetate restores hypothalamic-pituitary-ovarian function in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) accounts for 90-95 % of worldwide diabetes cases and is primarily characterized by insulin resistance. Its progression as a chronic metabolic disease has been largely associated with female reproductive abnormalities, including ovarian dysfunction with consequent infertility. Epigenetic modifications have been suggested as a possible link to metabolic comorbidities. We therefore hypothesized that short chain fatty acids, acetate (ACA), a potential histone deacetylase inhibitor (HDAC) ameliorates hypothalamic-pituitary-ovarian (HPO) dysfunction in T2DM. Female Wistar rats weighing 160-190 g were allotted into three groups (n = 6/group): Control (vehicle; po), T2D and T2D + ACA (200 mg/kg; po). T2DM was induced by fructose administration (10 %; w/v) for 6 weeks and single dose of streptozotocin (35 mg/kg; ip). The present data showed that in addition to insulin resistance, increased fasting blood glucose and insulin, T2DM induced elevated plasma, hypothalamic and ovarian triglyceride, lipid peroxidation, TNF-α and glutathione depletion. Aside, T2DM also led to increased plasma lactate production and γ-Glutamyl transferase as well as decreased gonadotropins/17β-estradiol. Histologically, hypothalamus, pituitary and ovaries revealed disrupted neuronal cells/moderate hemorrhage, altered morphology/vascular congestions, and degenerated antral follicle/graafian follicle with mild fibrosis and infiltrated inflammatory cells respectively in T2D animals. Interestingly, these alterations were accompanied by elevated plasma/hypothalamic HDAC5 and attenuated when treated with acetate. The present results demonstrate that T2DM induces HPO dysfunction, which is accompanied by elevated circulating/hypothalamic HDAC5. The results in addition suggest that acetate restores HPO function in T2DM by suppression of HDAC5 and enhancement of insulin sensitivity.

Transcriptome Profiling of Oocytes at the Germinal Vesicle Stage from Women from Mongolia with Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders. Evidence indicates that genetic and environmental factors contribute to the pathogenesis of PCOS. The molecular basis of PCOS is not well understood.

Methods

Whole-genome RNA sequencing was performed on single oocyte at the germinal vesicle (GV) stage from females with normal ovulation and females with PCOS. All subjects were women from Mongolia undergoing intracytoplasmic sperm injection in vitro fertilization (ICSI-IVF) who met the Rotterdam criteria for PCOS. Women with normal ovulation who were undergoing ICSI-IVF owing to male factor infertility were recruited as control subjects.

Results

A total of 1313 differentially expressed genes were found by bio-informatics software in the GV oocytes of PCOS patients and compared with the control group. There were 367 upregulated and 946 downregulated genes (fold change > 2, false discovery rate < 0.01). When compared with the healthy controls, it was shown that the DEGs like VEGF, IGF, FADS1 et al were investigated as potential causes of PCOS oocytes. The DEGs were related to kinase activity, cell proliferation, gene regulation, and the signaling pathways of phosphatidylinositol 3-kinase, Hippo, and ECM-receptor pathway in patients with PCOS. In addition, the interconnected gene co-expression network was constructed by gene bionetwork analysis, indicating that ITGB5, ITGB3, and CAV2 were the core genes in regulating the module expression of DEGs in PCOS.

Conclusion

RNA sequencing analysis demonstrated DEGs were linked to inflammation, cardiovascular disease, and lipid metabolism in the GV oocytes of women with PCOS. We hypothesize that ITGB5, ITGB3, and CAV2 may be involved in metabolic disorders associated with the different phenotypes of PCOS.

The Effects of Salvia miltiorrhiza on Reproduction and Metabolism in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Objective

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. As a traditional medicine, Salvia miltiorrhiza (S. miltiorrhiza) has been widely used in the treatment of many gynecological diseases, but the efficacy of S. miltiorrhiza in women with PCOS has not been assessed. The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of S. miltiorrhiza in women with PCOS.

Methods

We conducted searches in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure, the Wanfang Database, the Chinese Scientific Journal Database, and the Chinese BioMedical database from inception to December 23, 2020, to identify studies that met the inclusion criteria. The quality of the evidence was estimated using the Cochrane Reviewer Handbook 5.0.0, and the meta-analysis was performed using RevMan 5.3.5 software.

Results

Six randomized controlled trials (RCTs) involving 390 patients with PCOS were included. The studies suggested that S. miltiorrhiza extract combined with letrozole (LET) was more effective in improving pregnancy rate (RR: 2.60, 95% CI: 1.06 to 6.39, P=0.04) compared to LET alone. S. miltiorrhiza extract was associated with decreased fasting blood glucose (MD: –0.25, 95% CI: –0.37 to –0.13, P < 0.0001), fasting insulin (MD: –1.16, 95% CI: –1.74 to –0.58, P < 0.0001), total cholesterol (TC) (MD: –0.58, 95% CI: –0.72 to –0.43, P < 0.00001), and triglycerides (TG) (MD: –0.31, 95% CI: –0.35 to –0.26, P < 0.00001) compared with placebo, but not with improvements in body mass index or waist-to-hip ratio (MD: –1.41, 95% CI: –4.81 to 2.00, P=0.42; MD: –0.02, 95% CI: –0.05 to 0.01, P=0.16, respectively). There was a significant difference between S. miltiorrhiza extract combined with cyproterone acetate (CPA) and CPA alone in terms of decreasing TC (MD: –0.77, 95% CI: –0.89 to –0.65, P < 0.00001), TG (MD: –0.43, 95% CI: –0.65 to –0.20, P < 0.0001), and low-density lipoprotein cholesterol (MD: –0.49, 95% CI: –0.66 to –0.33, P < 0.00001) and increasing high-density lipoprotein cholesterol (MD: 0.30, 95% CI: 0.20, 0.40, P < 0.00001). In addition, S. miltiorrhiza extract also decreased testosterone, follicle-stimulating hormone, and luteinizing hormone. The studies did not mention any adverse events with S. miltiorrhiza extract.

Conclusion

The current studies indicate that S. miltiorrhiza has beneficial effects on reproduction and glucose and lipid metabolism in patients with PCOS, and it is generally safe for clinical application. However, more prospective RCTs with large samples, multiple centers, and longer intervention duration are needed in the future to obtain more reliable conclusions.

Brown Adipose Tissue Activation by Cold Treatment Ameliorates Polycystic Ovary Syndrome in Rat

Polycystic ovary syndrome (PCOS) is a common endocrine disease accompanied by energetic metabolic imbalance. Because the etiology of PCOS is complex and remains unclear, there is no effective and specific treatment for PCOS. It is often accompanied by various metabolic disorders such as obesity, insulin resistances, and others. Activated brown adipose tissue (BAT) consumes excess energy via thermogenesis, which has positive effects on energy metabolism. Our previous research and that of others indicates that BAT activity is decreased in PCOS patients, and exogenous BAT transplantation can improve PCOS rodents. Notably however, it is difficult to apply this therapeutic strategy in clinical practice. Therapeutic strategies of enhancing endogenous BAT activity and restoring whole-body endocrine homeostasis may be more meaningful for PCOS treatment. In the current study, the dehydroepiandrosterone-induced PCOS rat was exposed to low temperature for 20 days. The results show that cold treatment could reverse acyclicity of the estrous cycle and reduce circulating testosterone and luteinizing hormone in PCOS rats by activating endogenous BAT. It also significantly reduced the expression of steroidogenic enzymes as well as inflammatory factors in the ovaries of PCOS rats. Histological investigations revealed that cold treatment could significantly reduce ovary cystic follicles and increase corpus luteum, indicating that ovulation was recovered to a normal level. Concordant with these results, cold treatment also improved fertility in PCOS rats. Collectively, these findings suggest that cold treatment could be a novel therapeutic strategy for PCOS.