Metabolic syndrome, androgens, and hypertension

Dihydrotestosterone induces arterial stiffening in female mice

BACKGROUND

Androgens are important sex hormones in both men and women and are supplemented when endogenous levels are low, for gender transitioning, or to increase libido. Androgens also circulate at higher levels in women with polycystic ovarian syndrome, a condition that increases the risk for cardiovascular diseases including hypertension and arterial stiffness. Since our previous work shows an important role for the G protein-coupled estrogen receptor (GPER) in arterial stiffness, we hypothesized that other hormones including androgens may impact arterial stiffness in female mice via downregulation of GPER.

METHODS

The impact of the non-aromatizable androgen dihydrotestosterone (DHT), the glucocorticoid dexamethasone, and the progestin medroxyprogesterone acetate (all 100 nM for 24 h) on GPER and ERα expression was assessed in cultured vascular smooth muscle cells using droplet digital PCR (ddPCR). To assess the in vivo impact of the DHT-induced downregulation of GPER, female ovary-intact C57Bl/6 mice at 15-16 weeks of age were treated with silastic capsules containing DHT for 4 weeks, one with a dosage expected to mimic human male DHT levels and another to double the expected human concentration (n = 8-9/group).

RESULTS

In cultured vascular smooth muscle cells, GPER mRNA was decreased by DHT (P = 0.001) but was not impacted by dexamethasone or medroxyprogesterone. In contrast, ERα expression in cultured cells was significantly suppressed by all three hormones (P < 0.0001). In control mice or mice treated with a single or double dose of DHT, a dose-dependent increase in body weight was observed (control 22 ± 2 g, single dose 24 ± 2 g, double dose 26 ± 2 g; P = 0.0002). Intracarotid stiffness measured via pulse wave velocity showed a more than two-fold increase in both DHT-treated groups (control 1.9 ± 0.3 m/s, single dose 4.3 ± 0.8 m/s, double dose 4.8 ± 1.0 m/s). This increase in arterial stiffness occurred independent of changes in blood pressure (P = 0.59). Histological analysis of aortic sections using Masson's trichrome showed a significant decrease in collagen between the control group (24 ± 5%) and the double dose group (17 ± 3%, P = 0.007), despite no changes in aortic wall thickness or smooth muscle content. Lastly, ddPCR showed that in vivo DHT treatment decreased aortic expression of both GPER (control 20 ± 5, single dose 10.5 ± 5.6, double dose 10 ± 4 copies/ng; P = 0.001) and ERα (control 54 ± 2, single dose 24 ± 13, and double dose 23 ± 12 copies/ng; P = 0.003).

CONCLUSIONS

These findings indicate that androgen promotes arterial stiffening and cardiovascular damage in female mice and is associated with decreased estrogen receptor expression. These data are important for transgender men, women using testosterone for fitness or reduced libido, as well as patients with polycystic ovarian syndrome.

The association between blood heavy metals level and sex hormones among postmenopausal women in the US

Introduction

Environmental pollutants could be implicated in female endocrine setting Q6 beyond traditional factors. Until now, few study has focused on the association of environmental exposure to heavy metals with sex hormones in postmenopausal women. This study intended to investigate whether serum levels of heavy metals(i.e., Cd, Pb, Hg, Mn, Se) would influence sex hormones in postmenopausal women.

Methods and results

A cross-sectional study was performed on 614 nationally representative participants from 2013-2016 National Health and Nutrition Examination Survey (NHANES) in the US. Multivariate linear regression models and restricted cubic spline plots revealed cadmium(Cd) had linear positive association with TT(β=3.25, 95%CI= 1.12, 5.38), bioavailable TT(β=1.78, 95%CI=0.36,3.21) and TT/E2(β=0.76, 95%CI=0.28,1.24), which was more apparent in natural menopausal and obese women. Lead(Pb) had linear positive association with SHBG(β=12.84, 95%CI= 6.77,18.91), which was apparent in nearly all subgroups except in normal BMI group, and TT/E2 (β=0.69, 95%CI 0.134,1.25), which was apparent in natural menopausal and normal BMI women. Manganese(Mn) had non-linear association with SHBG, which was more apparent in natural menopausal and obese women, and TT/E2, which was more apparent in natural menopausal and normal BMI women. Selenium(Se) had U shaped non-linear association with TT, which was more apparent in hysterectomy, overweight and obese women, and SHBG, which was apparent in nearly all subgroups except in normal BMI group.

Conclusion

In summary, this cross-sectional study indicates a possible role that various degree of environmental exposure to heavy metals plays in the disruption of sex Q5 hormone levels in postmenopausal women. Further experiments are needed to elucidate the underlying mechanisms.

Dihydrotestosterone Induces Arterial Stiffening in Female Mice

Background

Testosterone is the predominant sex hormone in men and is increased in women with polycystic ovarian syndrome. These patients also experience an increased risk for cardiovascular diseases including hypertension and arterial stiffness. Since our previous work shows an important role for the G protein-coupled estrogen receptor (GPER) in arterial stiffness, we hypothesized that other hormones including androgens may impact arterial stiffness in female mice via regulation of GPER.

Methods

The impact of the non-aromatizable androgen dihydrotestosterone (DHT), the glucocorticoid dexamethasone, and the progestin medroxyprogesterone acetate (all 100 nM for 24 h) on GPER and ERα expression was assessed in cultured vascular smooth muscle cells using droplet digital PCR (ddPCR). To assess the in vivo impact of the DHT-induced downregulation of GPER, female ovary-intact C57Bl/6 mice were treated with silastic capsules containing DHT for 4 weeks, one with a dosage expected to mimic human male DHT levels and another to double the expected human concentration (n=8-9/group).

Results

GPER mRNA was only decreased by DHT (P=0.001), while ERα expression was significantly suppressed by all hormones (P<0.0001). While blood pressure was not different between groups (P= 0.59), there was a dose-dependent increase in body weight (control 22±2 g, single dose 24±2 g, double dose 26±2 g; P=0.0002). Intracarotid stiffness measured via pulse wave velocity showed a more than two-fold increase in both DHT-treated groups (control 1.9±0.3 m/s, single dose 4.3±0.8 m/s, double dose 4.8±1.0 m/s). Histological analysis of aortic sections using Masson's trichrome showed a significant decrease in collagen between the control group (24 ± 5%) and the double dose group (17 ± 3%, P=0.007), despite no changes in aortic wall thickness or smooth muscle content. Lastly, ddPCR showed that in vivo DHT treatment decreased aortic expression of both GPER (control 20±5, single dose 10.5 ± 5.6, double dose 10±4 copies/ng; P=0.001) and ERα (control 54±2, single dose 24±13, and double dose 23 ± 12 copies/ng; P=0.003).

Conclusions

These findings indicate that testosterone promotes arterial stiffening and cardiovascular damage in female mice and is associated with decreased estrogen receptor expression. These data are important not only for polycystic ovarian syndrome patients but also women using testosterone for fitness, gender transitioning, or reduced libido.

Machine learning integration of multimodal data identifies key features of blood pressure regulation

BACKGROUND

Association studies have identified several biomarkers for blood pressure and hypertension, but a thorough understanding of their mutual dependencies is lacking. By integrating two different high-throughput datasets, biochemical and dietary data, we aim to understand the multifactorial contributors of blood pressure (BP).

METHODS

We included 4,863 participants from TwinsUK with concurrent BP, metabolomics, genomics, biochemical measures, and dietary data. We used 5-fold cross-validation with the machine learning XGBoost algorithm to identify features of importance in context of one another in TwinsUK (80% training, 20% test). The features tested in TwinsUK were then probed using the same algorithm in an independent dataset of 2,807 individuals from the Qatari Biobank (QBB).

FINDINGS

Our model explained 39·2% [4·5%, MAE:11·32 mmHg (95%CI, +/- 0·65)] of the variance in systolic BP (SBP) in TwinsUK. Of the top 50 features, the most influential non-demographic variables were dihomo-linolenate, cis-4-decenoyl carnitine, lactate, chloride, urate, and creatinine along with dietary intakes of total, trans and saturated fat. We also highlight the incremental value of each included dimension. Furthermore, we replicated our model in the QBB [SBP variance explained = 45·2% (13·39%)] cohort and 30 of the top 50 features overlapped between cohorts.

INTERPRETATION

We show that an integrated analysis of omics, biochemical and dietary data improves our understanding of their in-between relationships and expands the range of potential biomarkers for blood pressure. Our results point to potentially key biological pathways to be prioritised for mechanistic studies.

FUNDING

Chronic Disease Research Foundation, Medical Research Council, Wellcome Trust, Qatar Foundation.

The Prevalence of Polycystic Ovary Syndrome, Its Phenotypes and Cardio-Metabolic Features in a Community Sample of Iranian Population: Tehran Lipid and Glucose Study

Objectives

The aim of the present study was to evaluate the prevalence of polycystic ovary syndrome (PCOS), its phenotypical and cardio-metabolic features in a community sample of the Iranian population in comparison to healthy eumenorrheic, non-hirsute women without polycystic ovaries. The second aim was to assess the cardio-metabolic characteristics of women who suffered from one criteria of PCOS compared to those healthy eumenorrheic, non-hirsute women.

Methods

In this cross-sectional population-based study, a total of 1,960 eligible women, aged (18-45 years) were recruited from the Tehran-Lipid and Glucose-Study participants and were classified as the three groups of (i) women with PCOS by the Rotterdam criteria, (ii) non-PCOS women with one criteria of PCOS and (iii) healthy eumenorrheic, non-hirsute women without polycystic ovaries morphology (PCOM) as the control group. Further PCOS women were extended to four phenotypes of hyperandrogenism, oligo-anovulation, polycystic ovaries (phenotype A), hyperandrogenism, oligo/anovulation (phenotype B), hyperandrogenism, polycystic ovaries (phenotype C) and oligo-anovulation, polycystic ovaries (phenotype D). Cardio-metabolic profiles and the prevalence of comorbidities of metabolic syndrome (MetS) and lipid abnormalities were compared among these groups linear, and the median regression models adjusted for age and body mass index.

Results

The prevalence of PCOS according to the diagnostic criteria of the NIH, Rotterdam and AE-PCOS Society were 13.6, 19.4, and 17.8, respectively. Among those who met the Rotterdam criteria, 23.9, 46.3, 21.6, and 8.2% had phenotypes A, B, C, and D, respectively. Among the remaining 1,580 women who did not fulfil the PCOS criteria, 108 (6.8%) suffered from only oligo/anovulation, 332 (21%) only hyperandrogenism/hyperandrogenemia, 159 (16.2%) only PCOM in ultrasound and 981 (62%) were healthy eumenorrheic, non-hirsute women without PCOM. The study revealed that some adiposity indices and lipid abnormalities in PCOS phenotypes with hyperandrogenism (A, B, and C) were worse than in healthy women. By contrast, women with phenotype D did not differ from the healthy ones in terms of adiposity and lipid abnormalities. However, the respective values for other cardio-metabolic profiles and MetS rates in different phenotypes of PCOS were similar to the healthy women. Only the prevalence of MetS in phenotype A was significantly higher than in the healthy women. There were no statistically significant differences between participants with one criteria of PCOS and healthy counterparts in terms of most adiposity indexes, cardio-metabolic factors, and comorbidity of MetS and its components. However, women with hyperandrogenism had a significantly higher level of the waist to height ratio (WHtR) and hypertriglyceridemia than their healthy counterparts.

Conclusion

PCOS, mainly classical phenotypes A and B, are common among Iranian women of reproductive age. Women with PCOS who had androgen excess exhibited the worst lipid profile, and those who had full three criteria of the syndrome exhibited the higher rate of MetS. However, women with only ovulatory dysfunction and only PCOM had similar cardio-metabolic characteristics, compared to healthy subjects. These data suggest that routine screening for metabolic disturbances may be needed in the prevention of cardio-metabolic disorders in patients with more serious phenotypes of PCOS.

Evaluation of Antifertility Effects of Sperm Immobilization Factor from Escherichia coli on Male Mice

Earlier in our laboratory, sperm immobilization factor (SIF) isolated from Escherichia coli has shown admirable contraceptive efficacy in female mice and thus generated interest in evaluating the same as a potential candidate for male contraception. Keeping this in mind, the present study was aimed at exploitation of SIF as contraceptive agent in male mouse model after intra testis administration. For this, Balb/c mice were administered with different concentrations (10, 50, 100, 200, or 400µg) of SIF and sacrificed on days 3,7,14,21,30,45,60, and 90. After sacrifice, results in terms of change in body weight, tissue somatic indices, seminal parameters, histology, hematological parameters, lipid peroxidation, testosterone level, and cytokines level were evaluated. The weight profile and TSI of all experimental groups showed no significant change. In case of seminal parameters, 400μg of SIF led to azoospermia up to 90 days and tissue histology also revealed hypo-spermatogenesis. No significant change was observed in haematological parameters after SIF (400µg) administration however, a significant decrease was observed in testosterone levels. The oxidative status and cytokines profile was also affected after SIF (400µg) inoculation. Thus, when administered via intra testis route, SIF can lead to azoospermia and poses to be a potent and safe antifertility agent.

Associations Between Peripheral Blood Microbiome and the Risk of Hypertension

BACKGROUND

Although previous studies have reported the gut microbiome is closely related to hypertension development, whether the change in blood microbiome is associated with the risk of hypertension remains unclear.

METHODS

One hundred and fifty incident hypertension cases and 150 age (± 2 years) and gender (1:1) matched nonhypertension controls included in this nested case-control study were recruited from a prospective cohort study of "135." The composition of the blood microbiome was characterized using bacterial 16S ribosomal RNA gene sequencing. The relative abundance of detected bacteria was converted to a negative logarithm of 10 for the statistical analysis.

RESULTS

Totally, 10,689,961 high-quality sequences were acquired. The Chao1 index of the blood microbiome in nonhypertension controls was significantly higher than in hypertensive group (2,302.08 ± 752.78 vs. 1,598.21 ± 500.88, P < 0.001). Compared with the nonhypertension controls, the relative abundance of Proteobacteria phylum was significantly increased (P < 0.001), whereas the relative abundance of phyla Firmicutes and Bacteroidetes were significantly reduced in the hypertensive cases (P < 0.001 and P = 0.039, respectively). At genus level, the risk of hypertension was directly associated with the relative abundance of Acinetobacter (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.01-2.03), Sphingomonas (OR: 1.84, 95% CI: 1.32-2.56), and Staphylococcus (OR: 0.51, 95% CI: 0.36-0.73), respectively. In addition, the relative abundance of Pseudomonas was minor positively correlated with the total cholesterol level. However, the relative Staphylococcus level was minor positively correlated with high-density lipoprotein cholesterol level.

CONCLUSIONS

The composition of the blood microbiome is significantly associated with the development of hypertension.

Racial and Sex Differences between Urinary Phthalates and Metabolic Syndrome among U.S. Adults: NHANES 2005-2014

Phthalates, plasticizers ubiquitous in household and personal care products, have been associated with metabolic disturbances. Despite the noted racial differences in phthalate exposure and the prevalence of metabolic syndrome (MetS), it remains unclear whether associations between phthalate metabolites and MetS vary by race and sex. A cross-sectional analysis was conducted among 10,017 adults from the National Health and Nutritional Examination Survey (2005–2014). Prevalence odds ratios (POR) and 95% confidence intervals (CIs) were estimated for the association between 11 urinary phthalate metabolites and MetS using weighted sex and race stratified multivariable logistic regression. Higher MCOP levels were significantly associated with increased odds of MetS among women but not men, and only remained significant among White women (POR _{Q4 vs. Q1} = 1.68, 95% CI: 1.24, 2.29; p-trend = 0.001). Similarly, the inverse association observed with MEHP among women, persisted among White women only (POR _{Q4 vs. Q1} = 0.53, 95% CI: 0.35, 0.80; p-trend = 0.003). However, ΣDEHP metabolites were associated with increased odds of MetS only among men, and this finding was limited to White men (POR _{Q4 vs. Q1} = 1.54, 95% CI: 1.01, 2.35; p-trend = 0.06). Among Black men, an inverse association was observed with higher MEP levels (POR _{Q4 vs. Q1} = 0.43, 95% CI: 0.24, 0.77; p-trend = 0.01). The findings suggest differential associations between phthalate metabolites and MetS by sex and race/ethnicity.

Serum free testosterone level in coronary artery disease in candidates for coronary artery bypass graft surgery: A cross-sectional study

Background

Due to the controversy over the effect of serum testosterone levels on coronary artery diseases, this survey explores the serum levels of free testosterone, luteinizing hormone, and follicle-stimulating hormone in candidates for coronary artery bypass graft compared with an age-matched control group and evaluates the associated factors in these participants.

Objective

To determine the testosterone level in elective coronary artery bypass grafting participants.

Materials and Methods

In this cross-sectional study, all male patients aged > 40 yr as candidates for elective coronary artery bypass grafting, who were referred to the Afshar Hospital, Yazd, Iran, from March 2018 to March 2019, were included. In total, 100 men were enrolled (50 cases and 50 controls). Their serum levels of free and total testosterone, luteinizing hormone, and follicle-stimulating hormone were measured and the results were compared.

Results

The findings indicated a significant difference between the two groups in total and free testosterone (both p < 0.001); they were lower in the case group. There was also a significant difference in the total testosterone of the participants with diabetes mellitus compared with no-diabetic individuals (p = 0.007). Free testosterone of diabetic subjects taking insulin was lower compared with those taking no insulin (p = 0.04). There was also an association between the body mass index and free testosterone, left ventricular ejection fraction and total testosterone, and a significant and negative relation between the duration of hospital admissions and free testosterone (p < 0.05).

Conclusion

This study illustrates that participants with coronary artery disease bear a significantly low testosterone level in comparison with the healthy control group.

The Association Between Dietary Inflammatory Index and Sex Hormones Among Postmenopausal Women in the US

AIMS

Diet has been found to have an important effect on sex hormones. The effect of diet-induced inflammation on sex hormones has not been studied in detail among women. Therefore, we aimed to investigate the association between energy-adjusted dietary inflammatory index (E-DII) and sex hormones among postmenopausal women.

METHODS

This study used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016 waves. A total of 1183 postmenopausal women who provided information on two 24-hour dietary intake recalls, sex hormones including total testosterone (TT), estradiol (E2), TT/E2, sex hormone-binding globulin (SHBG), free estradiol (FE2) and free testosterone (FT), as well as selected covariates were included. Linear regression and restricted cubic spline evaluated the association between E-DII and sex hormones. Effect modification by body mass index (BMI) and type of menopause was then examined in stratified analysis.

RESULTS

After adjusting for covariates, linear regression showed that E-DII was positively associated with TT (P=0.035), FT (P=0.026) and TT/E2 (P=0.065). TT (P-nonlinear = 0.037) and TT/E2 (P-nonlinear = 0.035) had significant nonlinear association with E-DII. E2 (P-nonlinear = 0.046) and FE2 (P-nonlinear = 0.027) depicted a nonlinear U-shaped significant association with E-DII, the two inflection points were found at the E-DII score of -0.22 and 0.07, respectively, the associations in natural menopausal women were more pronounced.

CONCLUSIONS

Our study indicates that several indicators of androgen and estrogen were associated with E-DII in postmenopausal women. Further research is needed to understand the underlying mechanisms.

Uric acid to HDL cholesterol ratio is a strong predictor of diabetic control in men with type 2 diabetes mellitus

AIM

Despite it has some disadvantages, the most important marker of diabetic control is glycated hemoglobin (HbA1c). Uric acid to HDL cholesterol ratio (UHR) is a promising marker in metabolic syndrome. We aimed to compare UHR levels of well and poorly controlled type 2 diabetic male subjects, as well as healthy men, and to observe its correlation with other metabolic parameters.

METHODS

Male patients with T2DM that showed up in outpatient internal medicine clinics of our hospital were enrolled to the study. Diabetic subjects divided into two groups according to the level of HbA1c: well-controlled T2DM group (HbA1c < 7%) and poorly controlled T2DM group (HbA1c ≥ 7%). Third group was consisted of healthy subjects without any chronic diseases. UHR levels of the groups were compared.

RESULTS

The UHR levels of well and poorly controlled diabetics and control subjects were 12%±5%, 17%±6% and 9%±3%, respectively (p<.001). The UHR was significantly and inversely correlated with GFR and was significantly and positively correlated with waist circumference, body weight, body mass index, serum creatinine, fasting plasma glucose (FPG) and HbA1c levels.

CONCLUSION

UHR could serve as a promising predictor of diabetic control in men with T2DM, since it has significant association with HbA1c and FPG levels.

Sperm impairing microbial factor: potential candidate for male contraception

BACKGROUND

Despite significant advances in contraceptive options for women, vasectomy and condoms are the only options available for male contraception. Due to this limitation, the burden of contraception resides on the shoulders of females only. Therefore, there is an urgent need to develop a safe, effective and reversible method of contraception for men. Amongst the alternative approaches, microbial derived products are gaining attention of the scientific world to combat unintended pregnancies. Earlier in our laboratory, sperm impairing microbial factor (Sperm immobilization factor) isolated from Staphylococcus aureus has shown excellent contraceptive efficacy in female mice. Keeping this in mind, the present study was carried out to exploit the sperm immobilization factor (SIF) as potential male contraceptive using vas deferens for administration in mouse model.

METHODS

SIF (10, 50, 100 or 200 μg) was inoculated in the lumen of right vas deferens whereas the left vas deferens served as control. The mice were sacrificed at Day 3, 7, 14, 21, 30, 45, 60 and 90 after inoculation and the results in terms of change in body weight, seminal parameters, Tissue somatic indices (TSI), haematological parameters, serum level of testosterone, lipid peroxidation and histology were studied. In order to ratify the SIF induced azoospermia SIF (200 μg) was administered with different doses viz. 100, 200, 300, 400 or 500 μg of SIF binding receptor extracted from mouse spermatozoa.

RESULTS

The weight profile studies of all the experimental groups showed no significant change in the initial and final body weight. In case of seminal parameters, the results revealed that right vas deferens treated with SIF showed azoospermia and with 200 μg of SIF it persisted up to 90 days. TSI of reproductive organs and non-reproductive organs showed no significant change in all the experimental groups. The haematological indices were found to be unaltered throughout the course of investigation however significant decrease in testosterone level was observed in the treated mice. The treatment also affected the oxidative status of the testis. Further, histological studies revealed hypospermatogenesis and late maturation arrest on treated side whereas the left side which served as control showed normal tissue histology. SIF induced azoospermia was ameliorated when administered with 400 μg of SIF binding receptor from mouse spermatozoa.

CONCLUSION

SIF, when administered via intra vas deferens route, could lead to complete azoospermia. Therefore, it could be considered as a potential male contraceptive.

The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts

INTRODUCTION

Cardiometabolic syndrome (CMS), as a bunch of metabolic disorders mainly characterized by type 2 diabetes mellitus (T2DM), hypertension, atherosclerosis, central adiposity, and abdominal obesity triggering androgen deficiency, is one of the most critical threats to men. Although many significant preclinical and clinical findings explain CMS, new approaches toward common pathophysiological mechanisms and reasonable therapeutic targets are lacking.

AIM

To gain a further understanding of the role of androgen levels in various facets of CMS such as the constellation of cardiometabolic risk factors including central adiposity, dyslipidemia, insulin resistance, diabetes, and arterial hypertension and to define future directions for development of effective therapeutic modalities.

METHODS

Clinical and experimental data were searched through scientific literature databases (PubMed) from 2009 to October 2019.

MAIN OUTCOME MEASURE

Evidence from basic and clinical research was gathered with regard to the causal impact and therapeutic roles of androgens on CMS.

RESULTS

There are important mechanisms implicated in androgen levels and the risk of CMS. Low testosterone levels have many signs and symptoms on cardiometabolic and glycometabolic risks as well as abdominal obesity in men.

CLINICAL IMPLICATIONS

The implications of the findings can shed light on future improvements in androgen levels and add potentially predictive risk for CMS, as well as T2DM, abdominal obesity to guide clinical management in the early stage.

STRENGTHS & LIMITATIONS

This comprehensive review refers to the association between androgens and cardiovascular health. A limitation of this study is the lack of large, prospective population-based studies that analyze the effects of testosterone treatment on CMS or mortality.

CONCLUSION

Low testosterone levels have several common features with metabolic syndrome. Thus, testosterone may have preventive role in the progress of metabolic syndrome and subsequent T2DM, abdominal obesity, and cardiovascular disease and likely affect aging men's health mainly through endocrine and vascular mechanisms. Further studies are necessary to evaluate the therapeutic interventions directed at preventing CMS in men. Kirlangic OF, Yilmaz-Oral D, Kaya-Sezginer E, et al. The Effects of Androgens on Cardiometabolic Syndrome: Current Therapeutic Concepts. Sex Med 2020;8:132-155.

Sex differences in non-alcoholic fatty liver disease: hints for future management of the disease

Non-alcoholic fatty liver disease (NAFLD) remains a major cause of chronic liver disease worldwide. Despite extensive studies, the heterogeneity of the risk factors as well as different disease mechanisms complicate the goals toward effective diagnosis and management. Recently, it has been shown that sex differences play a role in the prevalence and progression of NAFLD. In vitro, in vivo, and clinical studies revealed that the lower prevalence of NAFLD in premenopausal as compared to postmenopausal women and men is mainly due to the protective effects of estrogen and body fat distribution. It has been also described that males and females present differential pathogenic features in terms of biochemical profiles and histological characteristics. However, the exact molecular mechanisms for the gender differences that exist in the pathogenesis of NAFLD are still elusive. Lipogenesis, oxidative stress, and inflammation play a key role in the progression of NAFLD. For NAFLD, only a few studies characterized these mechanisms at the molecular level. Therefore, we aim to review the reported differential molecular mechanisms that trigger such different pathogenesis in both sexes. Differences in lipid metabolism, glucose homeostasis, oxidative stress, inflammation, and fibrosis were discussed based on the evidence reported in recent publications. In conclusion, with this review, we hope to provide a new perspective for the development of future practice guidelines as well as a new avenue for the management of the disease.

Hypertension and Reproduction

PURPOSE OF REVIEW

Many aspects of reproduction have been associated with increased blood pressure and impaired glucose metabolism that reveals a subsequent increased risk of cardiovascular disease. The aim of this review is to assess reproductive life factors associated with an increased risk of hypertension and cardiovascular disease, e.g., early life programming, sexual, and reproductive health in men and women.

RECENT FINDINGS

Impaired fetal growth, with low birth weight adjusted for gestational age, has been found associated with hypertension in adulthood. Erectile dysfunction, currently considered an early diagnostic marker of cardiovascular disease preceding the manifestation of coronary artery disease by several years, frequently coexisting with hypertension, could also be exacerbated by some antihypertensive drugs. Male hypogonadism or subfertility are associated with increased cardiovascular risk. Hypertensive disorders in pregnancy including preeclampsia represent a major cause of maternal, fetal and neonatal morbidity, and mortality. The risk of developing preeclampsia can be substantially reduced in women at its high or moderate risk with a low dose of acetylsalicylic acid initiated from 12 weeks of gestation. An increased risk of hypertension in women following invasive-assisted reproductive technologies has been newly observed. Blood pressure elevation has been noticed following contraceptive pill use, around the menopause and in postmenopausal age. Furthermore, drug treatment of hypertension has to be considered as a factor with a potential impact on reproduction (e.g., due to teratogenic drug effects). In summary, a deeper understanding of reproductive life effects on hypertension and metabolic abnormalities may improve prediction of future cardiovascular disease.

Isomers of perfluoroalkyl substances and overweight status among Chinese by sex status: Isomers of C8 Health Project in China

Previous investigations on the associations of polyfluoroalkyl substances (PFASs) with overweight/obesity are mixed. Moreover, little information has been reported about the association between isomers of PFASs with body mass index (BMI), waist circumference (WC) or overweight. To address this shortcoming in the literature, we conducted a study involving 1612 Chinese adults (1204 men and 408 women), ages 22-96 years old, from Shenyang, China, to analyze serum isomers of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other PFASs. Height, weight and WC were measured by a standardized protocol of WHO. Results indicated that increased serum concentrations of all (both branched and linear) isomers of PFASs were associated with a higher prevalence of overweight, and these associations were more pronounced in women. The adjusted odds ratios (ORs) from logistic regression analyses among women were 1.45 (95% confidence interval [CI]: 1.06, 1.99) for linear PFOS isomers, 1.33 (95% CI: 1.00, 1.77) for branched PFOS isomers, 1.39 (95% CI: 1.06, 1.81) for 3 + 4 + 5m PFOS, 1.54 (95% CI: 1.08, 2.21) for linear PFOA isomers, and 1.62 (95% CI: 1.05, 2.51) for branched PFOA isomers, respectively. Associations with increased WC were yielded a similar pattern. Linear regression models also showed positive associations between PFASs and BMI or WC. In conclusion, this study suggests that PFASs and their isomers are positively associated with overweight or increased WC, and the associations are stronger in women. Furthermore, PFOA and its isomers displayed the most robust obesogenic associations.

The Relation Between Free Testosterone and Components of Metabolic Syndrome in Women With Polycystic Ovary Syndrome

Objective: To assess the relationship between free testosterone level and components of MS in women with PCOS. Materials and methods: This is a cross-sectional study which was conducted on 215 women with PCOS. PCOS was diagnosed based on the Rotterdam criteria. Patients were divided into two subgroups of patients with and without MS based on ATP III criteria. In each subgroup, the association between individual components of MS with free testosterone was measured. Data were analyzed using SPSS software. Results: The prevalence of MS was 28.8% (n = 62). The mean level of free testosterone in patients with blood pressure ≥ 130/85 was significantly higher than those with blood pressure < 130/85 mm/hg. (p = 0.029) Also, in patients with diastolic blood pressure ≥ 85, the level of free testosterone was significantly higher than patients with diastolic blood pressure < 85. (p = 0.026). Results showed significant positive correlation between the level of free testosterone and cholesterol (p = 0.024). But no significant correlation was noted between levels of free testosterone and other variables. Conclusion: Regarding the relationship between blood pressure and high levels of free testosterone, it seems that regular blood pressure screening has a higher priority of concern comparing other complications for preventing cardiovascular adverse effects in women with PCOS and hyperandrogenism.

Androgens and Hypertension in Men and Women: a Unifying View

PURPOSE OF REVIEW

This review was designed to revaluate the androgen role on the mechanisms of hypertension and cardiovascular risks in both men and women. Sex steroids are involved in the regulation of blood pressure, but pathophysiological mechanism is not well understood. Androgens have an important effect on metabolism, adipose and endothelial cell function, and cardiovascular risk in both men and women. A focal point in this contest is represented by the possible gender-specific regulation of different tissues and in particular of the adipose cell. Available data confirm that androgen deficiency is linked to increased prevalence of hypertension and cardiovascular diseases. Adipocyte dysfunction seems to be the main involved mechanism. Androgen replacement reduces inflammation state in man, protecting by metabolic syndrome progression. In women, androgen excess has been considered as promoting factor of cardiovascular risk. However, recent data suggest that excessive androgen production has little effect per se in inducing hypertension in young women of reproductive age. Also in postmenopausal women, data on relative androgen excess and hypertension are missing, while adrenal androgen deficiency has been associated to increased mortality.

RECENT FINDINGS

Molecular mechanisms linking androgen dysregulation to hypertension are almost Unknown, but they seem to be related to increased visceral fat, promoting a chronic inflammatory state through different mechanisms. One of these may involve the recruitment and over-activation of NF-kB, a ubiquitous transcription factor also expressed in adipose cells, where it may cause the production of cytokines and other immune factors. The NF-kB signalling pathway may also influence brown adipogenesis leading to the preferential enlargement of visceral adipocytes. Chronic inflammation and adipocyte dysfunction may alter endothelial function leading to hypertension. Both in men and in women, particularly in the post-menopausal period, hypoandrogenism seems to be a major determinant of the increased prevalence of hypertension. The relationship between androgen signalling and NF-kB might explain the pathophysiological mechanism leading to the development of endothelium dysfunction and hypertension.

Prepubertal Di-n-Butyl Phthalate Exposure Alters Sertoli and Leydig Cell Function and Lowers Bone Density in Adult Male Mice

Phthalate exposure impairs testis development and function; however, whether phthalates affect nonreproductive functions is not well understood. To investigate this, C57BL/6J mice were fed 1-500 mg di-n-butyl phthalate (DBP) in corn oil, or vehicle only, daily from 4 to 14 days, after which tissues were collected (prepubertal study). Another group was fed 1-500 mg/kg·d DBP from 4 to 21 days and then maintained untreated until 8 weeks for determination of adult consequences of prepubertal exposure. Bones were assessed by microcomputed tomography and dual-energy X-ray absorptiometry and T by RIA. DBP exposure decreased prepubertal femur length, marrow volume, and mean moment of inertia. Adult animals exposed prepubertally to low DBP doses had lower bone mineral content and bone mineral density and less lean tissue mass than vehicle-treated animals. Altered dynamics of the emerging Leydig population were found in 14-day-old animals fed 100-500 mg/kg·d DBP. Adult mice had variable testicular T and serum T and LH concentrations after prepubertal exposure and a dose-dependent reduction in cytochrome p450, family 11, subfamily A, polypeptide 1. Insulin-like 3 was detected in Sertoli cells of adult mice administered the highest dose of 500 mg/kg·d DBP prepubertally, a finding supported by the induction of insulin-like 3 expression in TM4 cells exposed to 50 μM, but not 5 μM, DBP. We propose that low-dose DBP exposure is detrimental to bone but that normal bone mineral density/bone mineral content after high-dose DBP exposure reflects changes in testicular somatic cells that confer protection to bones. These findings will fuel concerns that low-dose DBP exposure impacts health beyond the reproductive axis.

Free androgen index as a predictor of blood pressure progression and accelerated vascular aging in menopause

BACKGROUND AND AIMS

We aimed to assess the prognostic value of free androgen index (FAI) and its change over time in arterial stiffness progression, endothelial function and hypertension in postmenopausal women.

METHODS

Postmenopausal women (n = 180) without clinically overt cardiovascular disease or diabetes were consecutively recruited and followed for a median of 29 months. The main outcome measures were changes over time in endothelial function (FMD), reflected waves, localized and systemic (PWV) arterial stiffness and hypertension.

RESULTS

Increased baseline FAI was significantly associated with new onset hypertension (OR for each SD, 2.71, 95% CI 1.14-6.41, p = 0.024), deterioration of pulse wave velocity (PWV) (0.414 m/s per SD), flow-mediated dilation (FMD) (-0.42% per SD), systolic (2.5 mmHg per SD) and pulse pressure progression (2.3 mmHg per SD, p < 0.05 for all). Baseline FAI remained an independent predictor of changes in PWV (p = 0.006), FMD (p = 0.02), peripheral pulse pressure (p = 0.028), transition to new onset hypertension (p = 0.001) and higher BP category (p = 0.012), after adjustment for age, changes in systolic blood pressure, traditional risk factors, vasoactive medication or total testosterone. Baseline FAI improved reclassification for the risk of transition into higher BP category (NRI = 47.5 ± 20.3%, p = 0.02) and abnormal PWV (NRI = 53.4 ± 23.2%, p = 0.021). Similarly, in a subgroup of patients with measured FAI at follow-up, its changes over time predicted changes in PWV, peripheral pulse pressure and hypertension status (p < 0.05 for all).

CONCLUSIONS

In apparently healthy postmenopausal women, FAI could be a novel biomarker superior to total testosterone for accelerated vascular aging and hypertension status.

Effective Delivery of Male Contraceptives Behind the Blood-Testis Barrier (BTB) - Lesson from Adjudin

The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in the mammalian body. It divides the seminiferous epithelium of the seminiferous tubule, the functional unit of the testis, where spermatogenesis takes place, into the basal and the adluminal (apical) compartments. Functionally, the BTB provides a unique microenvironment for meiosis I/II and post-meiotic spermatid development which take place exclusively in the apical compartment, away from the host immune system, and it contributes to the immune privilege status of testis. However, the BTB also poses major obstacles in developing male contraceptives (e.g., adjudin) that exert their effects on germ cells in the apical compartment, such as by disrupting spermatid adhesion to the Sertoli cell, causing germ cell exfoliation from the testis. Besides the tight junction (TJ) between adjacent Sertoli cells at the BTB that restricts the entry of contraceptives from the microvessels in the interstitium to the adluminal compartment, drug transporters, such as P-glycoprotein and multidrug resistance-associated protein 1 (MRP1), are also present that actively pump drugs out of the testis, limiting drug bioavailability. Recent advances in drug formulations, such as drug particle micronization (<50 μm) and co-grinding of drug particles with ß-cyclodextrin have improved bioavailability of contraceptives via considerable increase in solubility. Herein, we discuss development in drug formulations using adjudin as an example. We also put emphasis on the possible use of nanotechnology to deliver adjudin to the apical compartment with multidrug magnetic mesoporous silica nanoparticles. These advances in technology will significantly enhance our ability to develop effective non-hormonal male contraceptives for men.

Metabolic syndrome, aging and involvement of oxidative stress

The prevalence of the metabolic syndrome, a cluster of cardiovascular risk factors associated with obesity and insulin resistance, is dramatically increasing in Western and developing countries. This disorder consists of a cluster of metabolic conditions, such as hypertriglyceridemia, hyper-low-density lipoproteins, hypo-high-density lipoproteins, insulin resistance, abnormal glucose tolerance and hypertension, that-in combination with genetic susceptibility and abdominal obesity-are risk factors for type 2 diabetes, vascular inflammation, atherosclerosis, and renal, liver and heart diseases. One of the defects in metabolic syndrome and its associated diseases is excess of reactive oxygen species. Reactive oxygen species generated by mitochondria, or from other sites within or outside the cell, cause damage to mitochondrial components and initiate degradative processes. Such toxic reactions contribute significantly to the aging process. In this article we review current understandings of oxidative stress in metabolic syndrome related disease and its possible contribution to accelerated senescence.

Androgen receptor in human endothelial cells

Androgen receptor (AR) is a ligand-inducible transcription factor, and a member of the steroid-thyroid-retinoid receptor superfamily, that mediates the biological effects of androgens in a wide range of physiological and pathological processes. AR expression was identified in vascular cells nearly 20 years ago, and recent research has shown that AR mediates a variety of actions of androgens in endothelial and vascular smooth muscle cells. In this mini-review, we review evidence indicating the importance of AR in human endothelial cell (HUVEC) homeostatic and pathogenic processes. Although a role for AR in the modulation of HUVEC biology is evident, the molecular mechanisms by which AR regulates HUVEC homeostasis and disease processes are not fully understood. Understanding these mechanisms could provide critical insights into the processes of pathogenesis of diseases ranging from cardiovascular disease to cancer that are major causes of human morbidity and mortality.

Testosterone: a metabolic hormone in health and disease

Testosterone is a hormone that plays a key role in carbohydrate, fat and protein metabolism. It has been known for some time that testosterone has a major influence on body fat composition and muscle mass in the male. Testosterone deficiency is associated with an increased fat mass (in particular central adiposity), reduced insulin sensitivity, impaired glucose tolerance, elevated triglycerides and cholesterol and low HDL-cholesterol. All these factors are found in the metabolic syndrome (MetS) and type 2 diabetes, contributing to cardiovascular risk. Clinical trials demonstrate that testosterone replacement therapy improves the insulin resistance found in these conditions as well as glycaemic control and also reduces body fat mass, in particular truncal adiposity, cholesterol and triglycerides. The mechanisms by which testosterone acts on pathways to control metabolism are not fully clear. There is, however, an increasing body of evidence from animal, cell and clinical studies that testosterone at the molecular level controls the expression of important regulatory proteins involved in glycolysis, glycogen synthesis and lipid and cholesterol metabolism. The effects of testosterone differ in the major tissues involved in insulin action, which include liver, muscle and fat, suggesting a complex regulatory influence on metabolism. The cumulative effects of testosterone on these biochemical pathways would account for the overall benefit on insulin sensitivity observed in clinical trials. This review discusses the current knowledge of the metabolic actions of testosterone and how testosterone deficiency contributes to the clinical disease states of obesity, MetS and type 2 diabetes and the role of testosterone replacement.

Association between markers of systemic inflammation, oxidative stress, lipid profiles, and insulin resistance in pregnant women

BACKGROUND

Increased levels of pro-inflammatory factors, markers of oxidative stress and lipid profiles are known to be associated with several complications. The aim of this study was to determine the association of markers of systemic inflammation, oxidative stress and lipid profiles with insulin resistance in pregnant women in Kashan, Iran.

METHODS

In a cross-sectional study, serum high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), fasting plasma glucose (FPG), serum insulin, 8-oxo-7, 8-dihydroguanine (8-oxo-G), total cholesterol, triglyceride, High density lipoprotein-cholesterol (HDL-cholesterol), and plasma total antioxidant capacity (TAC) were measured among 89 primigravida singleton pregnant women aged 18-30 years at 24-28 weeks of gestation. Pearson's correlation and multiple linear regressions were used to assess their relationships with homeostatic model assessment of insulin resistance (HOMA-IR).

RESULTS

We found that among biochemical indicators of pregnant women, serum hs-CRP and total cholesterol levels were positively correlated with HOMA-IR (β = 0.05, P = 0.006 for hs-CRP and β = 0.006, P = 0.006 for total cholesterol). These associations remained significant even after mutual effect of other biochemical indicators were controlled (β = 0.04, P = 0.01 for hs-CRP and β = 0.007, P = 0.02 for total cholesterol). Further adjustment for body mass index made the association of hs-CRP and HOMA-IR disappeared; however, the relationship for total cholesterol remained statistically significant.

CONCLUSION

Our findings showed that serum total cholesterol is independently correlated with HOMA-IR score. Further studies are needed to confirm our findings.

Testosterone exerts selective anti-inflammatory effects on human skin mast cells in a cell subset dependent manner

Androgens are known to exert anti-inflammatory effects but their impact on mast cells (MCs) remains to be determined. Here, we show that MCs isolated from human foreskin samples (male) and those from breast skin (female) express the androgen receptor, albeit with a 10-fold difference between the subsets. While fundamental MC properties (FcεRI, c-Kit, tryptase; histamine release upon FcεRI cross-linking) were unaffected or slightly reduced (chymase) by testosterone, the hormone had a more profound impact on the production of cytokines, with IL-6 being a target (reduction by 53%). Interestingly, this effect was limited to breast skin MCs (15 of 16 donors displayed this phenomenon), but was not reproduced by foreskin MCs. Collectively, effector functions of human skin MCs are modulated by androgens in a gene-selective and MC subset-specific fashion. Possibly, MCs from women are more susceptible to testosterone. We also demonstrate that MC IL-6 production is highly variable among individuals.

Sex differences in developmental programming models

The theory of developmental programming suggests that diseases such as the metabolic syndrome may be ‘programmed’ by exposure to adverse stimuli during early development. The developmental programming literature encompasses the study of a wide range of suboptimal intrauterine environments in a variety of species and correlates these with diverse phenotypic outcomes in the offspring. At a molecular level, a large number of variables have been measured and suggested as the basis of the programmed phenotype. The range of both dependent and independent variables studied often makes the developmental programming literature complex to interpret and the drawing of definitive conclusions difficult. A common, though under-explored, theme of many developmental programming models is a sex difference in offspring outcomes. This holds true across a range of interventions, including dietary, hypoxic, and surgical models. The molecular and phenotypic outcomes of adversein uteroconditions are often more prominent in male than female offspring, although there is little consideration given to the basis for this observation in most studies. We review the evidence that maternal energy investment in male and female conceptuses may not be equal and may be environment dependent. It is suggested that male and female development could be viewed as separate processes from the time of conception, with differences in both timing and outcomes.

Inflammatory cause of metabolic syndrome via brain stress and NF-κB

Metabolic syndrome, a network of medical disorders that greatly increase the risk for developing metabolic and cardiovascular diseases, has reached epidemic levels in many areas of today's world. Despite this alarming medicare situation, scientific understandings on the root mechanisms of metabolic syndrome are still limited, and such insufficient knowledge contributes to the relative lack of effective treatments or preventions for related diseases. Recent interdisciplinary studies from neuroendocrinology and neuroimmunology fields have revealed that overnutrition can trigger intracellular stresses to cause inflammatory changes mediated by molecules that control innate immunity. This type of nutrition-related molecular inflammation in the central nervous system, particularly in the hypothalamus, can form a common pathogenic basis for the induction of various metabolic syndrome components such as obesity, insulin resistance, and hypertension. Proinflammatory NF-κB pathway has been revealed as a key molecular system for pathologic induction of brain inflammation, which translates overnutrition and resulting intracellular stresses into central neuroendocrine and neural dysregulations of energy, glucose, and cardiovascular homeostasis, collectively leading to metabolic syndrome. This article reviews recent research advances in the neural mechanisms of metabolic syndrome and related diseases from the perspective of pathogenic induction by intracellular stresses and NF-κB pathway of the brain.

Correlation between sex hormone levels and obesity in the elderly male

OBJECTIVE

To investigate the levels of sex hormones and androgen receptor (AR) in elderly male patients and to explore a possible correlation with obesity.

METHODS

The cross-sectional study included 314 Elderly males (age ≥ 65 year). Of these subjects, 104 were healthy (age range 65-92 year; mean 71.38 ± 5.154 year), 74 were obese (65-87 year; 71.32 ± 4.74 year), and 111 were overweight (65-85 year; 71.43 ± 5.03 year). The following parameters were measured: total testosterone (TT), free testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin (SHBG), estradiol (E2), luteinizing hormone, follicle-stimulating hormone and AR.

RESULTS

(i) The levels of TT and SHBG in the obesity group were significantly lower than those in non-obese subjects. (ii) Body mass index (BMI) negatively correlated with TT and SHBG. (iii) Multiple regression analysis revealed that TT (β: -0.230; p = 0.045) and SHBG (β: -0.163; p = 0.02) were statistically correlated with BMI.

CONCLUSION

Testosterone levels in the obese population were significantly lower than in the non-obese population and there is a significant association between testosterone levels and the extent of obesity.

Hypothalamic inflammation: a double-edged sword to nutritional diseases

The hypothalamus is one of the master regulators of various physiological processes, including energy balance and nutrient metabolism. These regulatory functions are mediated by discrete hypothalamic regions that integrate metabolic sensing with neuroendocrine and neural controls of systemic physiology. Neurons and nonneuronal cells in these hypothalamic regions act supportively to execute metabolic regulations. Under conditions of brain and hypothalamic inflammation, which may result from overnutrition-induced intracellular stresses or disease-associated systemic inflammatory factors, extracellular and intracellular environments of hypothalamic cells are disrupted, leading to central metabolic dysregulations and various diseases. Recent research has begun to elucidate the effects of hypothalamic inflammation in causing diverse components of metabolic syndrome leading to diabetes and cardiovascular disease. These new understandings have provocatively expanded previous knowledge on the cachectic roles of brain inflammatory response in diseases, such as infections and cancers. This review describes the molecular and cellular characteristics of hypothalamic inflammation in metabolic syndrome and related diseases as opposed to cachectic diseases, and also discusses concepts and potential applications of inhibiting central/hypothalamic inflammation to treat nutritional diseases.

Quantitative trait loci that control body weight and obesity in an F2 intercross between C57BL/6J and DDD.Cg-Ay mice

I have developed a congenic mouse strain for the A(y) allele at the agouti locus in an inbred DDD/Sgn strain, DDD.Cg-A(y). DDD.Cg-A(y) females are extremely obese and significantly heavier than B6.Cg-A(y) females. The objectives of this study were to determine the genetic basis of obesity in DDD.Cg-A(y) mice, and to determine whether or not their high body weight was due to the presence of DDD background-specific modifiers. I performed quantitative trait locus (QTL) analyses for body weight and body mass index in two types of F(2) mice [F2 A(y) (F(2) mice carrying the A(y) allele) and F(2) non-A(y) (F2 mice without the A(y) allele)] produced by crossing C57BL/6J females and DDD.Cg-A(y) males. The results of the QTL analysis of F(2) A(y) mice were very similar to those obtained for F(2) non-A(y) mice. It was unlikely that the high body weight of DDD.Cg-A(y) mice was due to the presence of specific modifiers. When both F(2) datasets were merged and analyzed, four significant body weight QTLs were identified on chromosomes 6, 9, and 17 (2 loci) and four significant obesity QTLs were identified on chromosomes 1, 6, 9, and 17. Although the presence of DDD background-specific modifiers was not confirmed, a multifactorial basis of obesity in DDD.Cg-A(y) females was thus revealed.

Adjudin, a potential male contraceptive, exerts its effects locally in the seminiferous epithelium of mammalian testes

Adjudin is a derivative of 1H-indazole-3-carboxylic acid that was shown to have potent anti-spermatogenic activity in rats, rabbits, and dogs. It exerts its effects most notably locally in the apical compartment of the seminiferous epithelium, behind the blood-testis barrier, by disrupting adhesion of germ cells, most notably spermatids to the Sertoli cells, thereby inducing release of immature spermatids from the epithelium that leads to infertility. After adjudin is metabolized, the remaining spermatogonial stem cells and spermatogonia repopulate the seminiferous epithelium gradually via spermatogonial self-renewal and differentiation, to be followed by meiosis and spermiogenesis, and thus fertility rebounds. Recent studies in rats have demonstrated unequivocally that the primary and initial cellular target of adjudin in the testis is the apical ectoplasmic specialization, a testis-specific anchoring junction type restricted to the interface between Sertoli cells and elongating spermatids (from step 8 to 19 spermatids). In this review, we highlight some of the recent advances and obstacles regarding the possible use of adjudin as a male contraceptive.