Expression of aquaporin proteins in vagina of diabetes mellitus rats

Obesity, Body Image Dissatisfaction, and Sexual Dysfunction: A Narrative Review

With approximately two-thirds of the United States adult population classified as overweight or obese, obesity remains a critical public health concern. Obesity not only contributes to several health complications including type 2 diabetes mellitus and cardiovascular disease, but the condition is also associated with sexual dysfunction in both women and men. Despite evidence linking obesity and its concomitant pathophysiology to sexual problems, the potential roles of psychosocial factors such as body image are understudied. This narrative review evaluates the research linkages between obesity and sexual dysfunction, with particular attention to the potential effects of body image dissatisfaction. A literature search of biomedical and psychological databases was used to identify research pertaining to obesity, sexual function, and/or body image constructs. The pathophysiological effects of obesity on sexual function are well-documented in mechanistic studies and animal trials, often with corroboration in human clinical samples. However, very few studies examine obesity, body image, and sexual function in tandem. Body image dissatisfaction appears to independently impinge upon the sexual response cycle and mental health outcomes, irrespective of body weight. While obesity is often associated with negative body image appraisal, it is unclear whether these constructs exert additive, synergistic, or antagonistic effects on sexual responsivity. Additionally, overweight/obese individuals who exhibit higher levels of body image satisfaction or self-confidence appear to be protected from the deleterious effects of obesity on sexual satisfaction, at least to some extent. Greater reliance upon conceptual/theoretical models from the body image literature may better clarify the relationships between these constructs.

Construction of circRNA-miRNA-mRNA Network for Exploring Underlying Mechanisms of Lubrication Disorder

Lubrication disorder is a common health issue that manifests as insufficient sexual arousal at the beginning of sex. It often causes physical and psychological distress. However, there are few studies on lubrication disorder, and the complexity of circular RNA (circRNA) and the related competing endogenous RNA (ceRNA) network in lubrication disorder is still poorly known. Therefore, this study aims to build a regulatory circRNA-micro (mi)RNA-mRNA network and explore potential molecular markers of lubrication disorder. In the study, 12 subjects were recruited, including 6 in the lubrication disorder group and 6 in the normal control group. RNA sequencing was exploited to identify the expression profiles of circRNA, miRNA and mRNA between two groups, and then to construct the circRNA-miRNA-mRNA networks. The enrichment analyses of the differentially expressed (DE)-mRNAs were examined via Gene Set Enrichment Analysis (GSEA). Furthermore, the expression level and interactions among circRNA, miRNA, and mRNA were validated using real-time quantitative polymerase chain reaction (RT-qPCR) and dual-luciferase reporter assays. In the results, 73 circRNAs, 287 miRNAs, and 354 target mRNAs were differentially expressed between two groups when taking | Log2 (fold change)| > 1 and P-value < 0.05 as criteria, and then the results of GSEA revealed that DE-mRNAs were linked with "vascular smooth muscle contraction," "aldosterone regulated sodium reabsorption," "calcium signaling pathway," etc. 19 target relationships among 5 circRNAs, 4 miRNAs, and 7 mRNAs were found and constructed the ceRNA network. Among them, hsa-miR-212-5p and hsa-miR-874-3p were demonstrated to be related to the occurrence of lubrication disorder. Eventually, consistent with sequencing, RT-qPCR showed that hsa_circ_0026782 and ASB2 were upregulated while hsa-miR-874-3p was downregulated, and dual-luciferase reporter assays confirmed the interactions among them. In summary, the findings indicate that the circRNA-miRNA-mRNA regulatory network is presented in lubrication disorder, and ulteriorly provide a deeper understanding of the specific regulatory mechanism of lubrication disorder from the perspective of the circRNA-miRNA-mRNA network.

Sexual Response in Women with Type 1 Diabetes Mellitus: A Controlled Laboratory Study Measuring Vaginal Blood Flow and Subjective Sexual Arousal

Previous studies have indicated that women with diabetes mellitus are at higher risk to develop sexual dysfunctions. In the current study, we hypothesized that lower genital arousal response-as a consequence of diabetes-related damage to nerves and blood vessels-might play a part in these higher prevalence rates. Vaginal blood flow, subjective sexual response, and clitoral sensitivity were compared between women with diabetes and healthy controls, and associations with diabetes complications were investigated. In pre- and postmenopausal women with type 1 diabetes (n = 42) and healthy controls (n = 46), vaginal blood flow was measured as vaginal pulse amplitude (VPA). VPA was assessed at rest, during erotic film viewing, and during vibrotactile clitoral stimulation. Subjective sexual arousal was measured using a questionnaire. Clitoral sensitivity was assessed by a vibration perception test. Data on diabetes complications were obtained from medical records, and neuropathy was assessed by quantitative sensory testing. VPA, subjective sexual arousal, and clitoral sensitivity were not significantly different between women with diabetes and controls. Nevertheless, women with diabetes who had retinopathy showed significantly lower VPA than women without retinopathy, and women with diabetes who had neuropathy showed significantly higher sensation thresholds for vibrotactile clitoral stimulation. The results do not support the hypothesis of a disrupted genital arousal response in women with diabetes. However, the observed associations between retinopathy and vaginal blood flow, and between neuropathy and clitoral sensitivity, suggest that diabetes-related complications might adversely affect the physiological basis of female sexual response.

Changes in vaginal physiology of menopausal women with type 2 diabetes

INTRODUCTION

Metabolic disorders, such as type 2 diabetes, have been associated with an increased risk of development of female sexual dysfunction (FSD). In experimental studies, vascular, neuronal, and hormonal responsiveness alteration at vaginal level were proposed as contributors to the onset of FSD in women with diabetes; however, conclusive data on humans are still lacking.

AIMS

The study aimed to assess changes in vascularization, sex steroid receptors, nitric oxide synthase, and aquaporin-2 (AQP2) expression occurring at vaginal level in women with diabetes.

METHODS

Vaginal biopsies were obtained from 21 postmenopausal women, 10 of whom were diagnosed as having type 2 diabetes mellitus. CD31, estrogen receptor-α (ERα) and androgen receptor (AR) expression and localization were analyzed by immunostaining. Expression of endothelial (eNOS) and neuronal (nNOS) nitric oxide synthase isoforms and AQP2 were also assessed in vaginal samples.

MAIN OUTCOMES MEASURES

Changes in vaginal vascularization, sex steroids receptor, eNOS, nNOS and AQP2 expression.

RESULTS

Vaginal samples from women with diabetes showed an increased microvessel density in the lamina propria, which were morphologically disrupted suggesting an angiogenic compensatory mechanism. While no differences were seen in ERα, AR expression was significantly reduced in the vaginal epithelium and lamina propria of women with diabetes. Similarly, the gene and protein expressions of both nNOS and eNOS were significantly reduced in patients with diabetes, while AQP2 mRNAs level did not significantly differ between the two groups.

CONCLUSION

Diabetes greatly impacts vaginal physiology, being associated with alterations of the vaginal lamina propria vascular network, nitrergic signaling, and AR expression. These alterations may contribute to the increased risk of FSD development in women with diabetes.

Sexuality and psychopathological aspects in premenopausal women with metabolic syndrome

INTRODUCTION

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors that have been suggested to impact female sexual function.

AIMS

This study aims to assess the prevalence of female sexual dysfunction (FSD) in premenopausal women with MetS compared with healthy controls (HC). Psychopathological aspects and the relationship to FSD were also evaluated in both groups.

METHODS

Two hundred four premenopausal women, of whom 98 had diagnosis of MetS, were asked to complete the Female Sexual Function Index (FSFI), the Female Sexual Distress Scale (FSDS), and the Middlesex Hospital Questionnaire (MHQ). Routine laboratory tests and anthropometric measurements were routinely performed.

MAIN OUTCOME MEASURES

FSFI and FSDS questionnaires, prevalence of FSD, and MHQ scores.

RESULTS

In the MetS group compared with the HC group, we found: a lower global FSFI score (P=0.005), higher prevalence of pathological scores compared with HC group, and lower scores in the desire, arousal, lubrication, and orgasm domains. An inverse correlation between the FSFI score and the number of risk factors for MetS was detected. MetS women reported significantly higher total scores in the somatization and depression domains when compared with the HC group. The logistic regression showed that high triglycerides (odds ratio [OR] 3.097; 95% confidence interval [CI] 1.272-7.542; P=0.026) and somatization (OR 7.068; CI 95% 2.291-21.812; P=0.001) are independently associated with FSD in premenopausal women.

CONCLUSIONS

Our results indicate a higher prevalence of sexual dysfunction in MetS women. A number of risk factors for MetS are positively associated with FSD and higher triglycerides seem to be the strongest predictors of sexual dysfunction. Psychopathological dimensions such as somatization are strongly associated with sexual dysfunction.

Activation of β-adrenergic receptors during sexual arousal facilitates vaginal lubrication by regulating vaginal epithelial Cl(-) secretion

INTRODUCTION

Vaginal lubrication, an indicator of sexual arousal and tissue health, increases significantly during genital sexual arousal. Adrenergic alpha-receptors (AR) are an important regulator of genital physiological responses involved in mediating vascular and nonvascular smooth muscle contractility; the role of β-AR in sexual arousal, however, has not yet been investigated.

AIM

The goal of this study was to reveal the functional role of β-AR in modulating vaginal lubrication during sexual arousal and the mechanisms underlying the process.

METHODS

The effects of adrenaline on vaginal epithelial ion transport, intracellular cyclic adenosine monophosphate (cAMP) content ([cAMP]i ), and vaginal lubrication were investigated using short-circuit current (ISC ) of rat vaginas incubated in vitro, enzyme-linked immunosorbent assay (ELISA), and measurement of vaginal lubrication in vivo, respectively. The expressions of β-AR in vaginal epithelium were analyzed by reverse transcription-polymerase chain reaction, western blot, and immunofluorescence.

MAIN OUTCOME MEASURES

Changes of ISC responses; mRNA, protein expressions and localization of β-AR; [cAMP]i ; vaginal lubrication.

RESULTS

Serosal application of adrenaline induced an increase of ISC across rat vaginal epithelium that blocked by propranolol, a β-AR antagonist, rather than phentolamine, an α-AR antagonist. β1/2-AR were both present in rat and human vaginal epithelial cells. Removing Cl(-) or application of CFTR(inh) -172, an inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR), abolished adrenaline-induced ISC responses. The elevated levels of [cAMP]i induced by adrenaline were prevented by the pretreatment with propranolol. Vaginal lubrication measured in vivo showed that adrenaline or pelvic nerve stimulation caused a marked increase in vaginal lubrication, whereas pretreatment with propranolol or CFTR(inh) -172 reduced the effect.

CONCLUSIONS

Activation of epithelial β-AR facilitates vaginal lubrication during sexual arousal by stimulating vaginal epithelial Cl(-) secretion in a cAMP-dependent pathway. Thus, vaginal epithelial β-AR might be another regulator of vaginal sexual arousal responses.

Expression of aquaporins in prostate and seminal vesicles of diabetic rats

INTRODUCTION

Aquaporins (AQPs) are membrane proteins that facilitate the movement of water and many small solutes across biological membranes. Seminal fluid is primarily produced by prostate and seminal vesicles, and its production may potentially be mediated by many mechanisms related to transudation of fluid. Epidemiological data suggest that semen volume in diabetic men is significantly less than in nondiabetic men.

AIM

To investigate the change in volume of secretions of the prostate and seminal vesicles in diabetic rats and its association with the expression of AQPs 1-4.

METHODS

Twenty male Sprague Dawley rats were randomly divided among 4- and 6-week diabetic groups and 4- and 6-week control groups. Prostate and seminal vesicle secretions were collected and measured, and levels of expression of AQPs 1-4 were determined by immunohistochemical study and Western blot.

MAIN OUTCOME MEASURES

The levels of expression of AQPs 1-4 were determined in the prostate and seminal vesicles of diabetic rats by Western blot and immunohistochemical study.

RESULTS

Plasma glucose was significantly higher in diabetic model groups than in controls (P < 0.05). The weights of secretions of the prostate and seminal vesicles were significantly lower in diabetic model groups (P < 0.05). The levels of expression of AQPs 1 and 4 in seminal vesicles were significantly lower in diabetic model groups (P < 0.05). There was no difference in the level of expression of AQP3 in seminal vesicles among the groups. The levels of expression of AQPs 1, 3, and 4 in prostate were significantly lower in diabetic model groups (P < 0.05). AQP2 was not detectable in the prostate or seminal vesicles of any of the groups.

CONCLUSIONS

Decreased weight of prostate secretions in diabetic rats may be partly due to decreased levels of AQPs 1, 3, and 4 in prostatic tissue. Decreased weight of seminal vesicle secretions in diabetic rats may be partly due to decreased levels of AQP1 and AQP4 in seminal vesicles. There is no relationship between the expression of AQPs 1-4 and the duration of disease.