Mitochondrial apoptotic pathways: a mechanism for low androgen-induced vascular endothelial injury in male rats

Acupuncture regulates the apoptosis of ovarian granulosa cells in polycystic ovarian syndrome-related abnormal follicular development through LncMEG3-mediated inhibition of miR-21-3p

BACKGROUND

The main features of polycystic ovary syndrome (PCOS) are abnormal follicular development and ovulatory dysfunction, which are caused by excessive apoptosis of ovarian granulosa cells. Acupuncture has been shown to improve follicular development abnormalities in patients with PCOS, but its mechanism is unknown. This study hypothesized that the mechanism of acupuncture on follicular development abnormalities in PCOS patients is the inhibition of granulosa cell apoptosis through LncMEG3-mediated regulation of miR-21-3p.

METHODS

A PCOS-like rat model was established using subcutaneous injection of dehydroepiandrosterone (DHEA). Acupuncture was performed on rats for 15 d (CV-4, RN-3, CV-6, SP-6 and EX-CA 1). Ovarian morphology was observed by HE staining, and sex hormone and AMH levels were detected by ELISA. Primary granulosa cells were isolated from each group of rats to assess the association of acupuncture treatment, LncMEG3, miR-21-3p, and granulosa cell apoptosis in rats with PCOS.

RESULTS

LncMEG3 and miR-21-3p were highly expressed in the ovarian granulosa cells of rats with PCOS, and LncMEG3-mediated regulation of miR-21-3p was involved in the development of PCOS in rats. Silencing of MEG3 attenuated sex hormone dysregulation and ovarian histopathological changes in PCOS rats and promoted follicle cell development and maturation. In addition, silencing MEG3 increased the viability and number of granulosa cells. In addition, silencing MEG3 further inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats. Acupuncture improved polycystic ovarian morphology and sex hormone levels in PCOS rats. Acupuncture intervention increased the viability and number of granulosa cells. Acupuncture intervention inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats by targeting miR-21-3p via LncMEG3.

CONCLUSION

These results suggest that acupuncture can downregulate LncMEG3, thereby targeting and regulating miR-21-3p to suppress early and late granulosa cell apoptosis and normalize their proliferation. These factors ultimately compensate for abnormal follicular development. These findings shed light on the clinical potential of acupuncture as a safe treatment for follicular developmental abnormalities in PCOS.

Low androgen status inhibits erectile function by up-regulating the expression of proteins of mitochondria-associated membranes in rat corpus cavernosum

OBJECTIVE

To investigate the effect of low androgen status on mitochondria-associated membranes (MAMs) and its relationship with erectile function.

METHODS

A total of 36 eight-week-old male Sprague-Dawley rats were randomly divided into 6 groups: the control (sham-operated) group, the castration group, the castration + testosterone (cast + T) group, the control + siRNA group, the cast + siRNA group, and the cast + empty vector group. Testosterone propionate (3 mg/kg) was subcutaneously injected into the rats in the cast + T group every other day starting from the second day after the surgery. Four weeks later, lentiviral vectors carrying phosphofurin acidic cluster sorting protein 2 (PACS-2) gene-specific siRNA (1 × 10⁸ TU/ mL, 10 μL) were injected into the rats in the siRNA groups. At the 6th week of castration, the ratio of the maximum intracavernous pressure/the mean arterial pressure (ICPmax/MAP), the levels of nitric oxide (NO), endothelial nitric oxide synthase (eNOS), phospho-eNOS (p-eNOS), fatty acid-CoA ligase 4 (FACL-4), PACS-2, and inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) in the penile corpus cavernosum were determined.

RESULTS

The FACL-4, PACS-2 and IP3R1 were primarily localized in the cytoplasm of endothelial cells and part of smooth muscle cells in the corpus cavernosum. The level of NO, the ratio of ICPmax/MAP, and p-eNOS/eNOS were decreased significantly in the castration group compared with the control group (P<0.01). The expressions of FACL-4, PACS-2, and IP3R1 were increased significantly in the castration group compared with the control group (P<0.01). The level of NO, the ratios of ICPmax/MAP, and the ratio of p-eNOS/eNOS were increased significantly in the cast + siRNA group compared with the castration group (P<0.01). The expressions of FACL-4 and PACS-2 were decreased significantly in the cast + siRNA group compared with the castration group (P<0.01).

CONCLUSION

Low androgen status up-regulated the expressions of patients in MAMs (FACL-4, PACS-2 and IP3R1) in the corpus cavernosum and inhibited the eNOS/NO/cGMP signaling pathway, resulting in impaired erectile function in rats. Erectile function may be improved by inhibiting the high expression of PACS-2 in the corpus cavernosum under low androgen state. This article is protected by copyright. All rights reserved.

Androgen-Regulated Cardiac Metabolism in Aging Men

The prevalence of cardiovascular mortality is higher in men than in age-matched premenopausal women. Gender differences are linked to circulating sex-related steroid hormone levels and their cardio-specific actions, which are critical factors involved in the prevalence and features of age-associated cardiovascular disease. In women, estrogens have been described as cardioprotective agents, while in men, testosterone is the main sex steroid hormone. The effects of testosterone as a metabolic regulator and cardioprotective agent in aging men are poorly understood. With advancing age, testosterone levels gradually decrease in men, an effect associated with increasing fat mass, decrease in lean body mass, dyslipidemia, insulin resistance and adjustment in energy substrate metabolism. Aging is associated with a decline in metabolism, characterized by modifications in cardiac function, excitation-contraction coupling, and lower efficacy to generate energy. Testosterone deficiency -as found in elderly men- rapidly becomes an epidemic condition, associated with prominent cardiometabolic disorders. Therefore, it is highly probable that senior men showing low testosterone levels will display symptoms of androgen deficiency, presenting an unfavorable metabolic profile and increased cardiovascular risk. Moreover, recent reports establish that testosterone replacement improves cardiomyocyte bioenergetics, increases glucose metabolism and reduces insulin resistance in elderly men. Thus, testosterone-related metabolic signaling and gene expression may constitute relevant therapeutic target for preventing, or treating, age- and gender-related cardiometabolic diseases in men. Here, we will discuss the impact of current evidence showing how cardiac metabolism is regulated by androgen levels in aging men.

Pathophysiology of Aortic Valve Stenosis: Is It Both Fibrocalcific and Sex Specific?

Our understanding of the fundamental biology and identification of efficacious therapeutic targets in aortic valve stenosis has lagged far behind the fields of atherosclerosis and heart failure. In this review, we highlight the most clinically relevant problems facing men and women with fibrocalcific aortic valve stenosis, discuss the fundamental biology underlying valve calcification and fibrosis, and identify key molecular points of intersection with sex hormone signaling.

Chronic high-dose creatine has opposing effects on depression-related gene expression and behavior in intact and sex hormone-treated gonadectomized male and female rats

Creatine is an antioxidant, neuromodulator and key regulator of energy metabolism shown to improve depressive symptoms in humans and animals, especially in females. To better understand the pharmacological effects of creatine, we examined its influence on depression-related hippocampal gene expression and behaviors in the presence and absence of sex steroids. Sham-operated and gonadectomized male and female rats were fed chow alone or chow blended with either 2% or 4% w/w creatine monohydrate for five weeks before forced swim, open field, and wire suspension tests, or seven weeks total. Before supplementation, males were chronically implanted with an empty or a testosterone-filled (T) capsule (10-mm surface release), and females were administered progesterone (P, 250 μg), estradiol benzoate (EB, 2.5 μg), EB+P, or sesame oil vehicle weekly. Relative to non-supplemented shams, all hippocampal plasticity-related mRNAs measured, including brain-derived neurotrophic factor (BDNF), tyrosine kinase B, doublecortin, calretinin, and calbindin, were downregulated in sham males given 4% creatine, and BDNF, doublecortin, and calbindin mRNAs were downregulated in sham females given 4% creatine. In contrast, combined 4% creatine+T in castrates prevented downregulation of BDNF, doublecortin, and calretinin mRNAs. Similarly, combined 4% creatine+EB+P in ovariectomized females attenuated downregulation of BDNF and calbindin mRNA levels. Moderate antidepressant and anxiolytic-like behaviors were observed in EB+P-treated ovariectomized females fed creatine, with similar trends in T-treated castrates fed creatine. Altogether, these data show that chronic, high-dose creatine has opposing effects on neuroplasticity-related genes and depressive behavior in intact and gonadectomized male and female rats. The dose and schedule of creatine used negatively impacted hippocampal neuronal integrity in otherwise healthy brains, possibly through negative compensatory changes in energy metabolism, whereas combined creatine and sex steroids acted in a neuroprotective manner in gonadectomized rats, potentially by reducing metabolic complications associated with castration or ovariectomy.