Bi-phasic regulation of miR-17~92 transcription during hypoxia: Roles of HIF1 and p53 hyperphosphorylation at ser15.

We have reported previously that during hypoxia exposure, the expression of mature miR-17~92 was first upregulated and then downregulated in pulmonary artery smooth muscle cells (PASMC) and in mouse lungs in vitro and in vivo. Here we investigated the mechanisms regulating this bi-phasic expression of miR-17~92 in PASMC in hypoxia. We measured the level of primary miR-17~92 in PASMC during hypoxia exposure and found that short-term hypoxia exposure (3%O2, 6 hours) induced the level of primary miR-17~92, while long-term hypoxia exposure (3%O2, 24 hours) decreased its level, suggesting a bi-phasic regulation of miR-17~92 expression at the transcriptional level. We found that short-term hypoxia-induced upregulation of miR-17~92 was HIF1α and E2F1 dependent. Two HIF1α binding sites on miR-17~92 promoter were identified. We also found that long-term hypoxia-induced suppression of miR-17~92 expression could be restored by silencing of p53. Mutation of the p53-binding sites in the miR-17~92 promoter increased miR-17~92 promoter activity in both normoxia and hypoxia. Our findings suggest that the bi-phasic transcriptional regulation of miR-17~92 during hypoxia is controlled by HIF1/E2F1 and p53 in PASMC: during short-term hypoxia exposure, stabilization of HIF1 and induction of E2F1 induces the transcription of miR-17~92; while during long-term hypoxia exposure, hyperphosphorylation of p53 suppresses the expression of miR-17~92.

Gender-affirming vaginoplasty: Technical considerations in patients with genital skin deficiency.

INTRODUCTION: Gender dysphoria affects over 1 million American adults. Vaginoplasty is a critical step in gender affirmation, and many patients have insufficient genital skin for full-depth penile inversion vaginoplasty (PIV). We reviewed the literature for technical considerations addressing this and present our data supporting the use of peritoneal flaps (Davydov technique). MATERIALS AND METHODS: A comprehensive review of modern literature was conducted. Second, we present a retrospective case review of our experience with PIV, including data from procedures utilizing peritoneal flaps. RESULTS: We identified 20 original articles, including retrospective and prospective case and cohort studies. Approaches included the application of local soft tissue grafts and flaps, peritoneal flaps, and intestinal segments. Between June 2018 and February 2021, 47 patients at our institution, underwent PIV for the treatment of gender dysphoria. Nineteen of those patients underwent robotic-assisted peritoneal flap procedure in addition to PIV. In this cohort, the mean follow-up was 200.6 ± 124.8 days. Mean neovaginal depth was 13.1 ± 3.0 cm intra-operatively and 11.0 cm at the last follow-up. Twenty-six percent of complications were Clavien Grade 1 or 2; others included wound dehiscence (30.4%), perianal and urethral fistula (13.0%), and neovaginal stenosis (8.7%). The majority of patients reported satisfactory results in terms of sexual function with intact tactile and erogenous sensation. Almost half were able to have penetrative vaginal intercourse at the last follow-up. We did not aim to perform statistical calculations to compare the outcomes of PIV with and without robotic-assisted peritoneal flap augmentation, as the groups were not constructed in that manner. However, it is evident that anatomical and functional results as well as the distribution of postoperative complications seem similar. CONCLUSION: Vaginoplasty is indicated in a growing population of patients with a wide range of medical histories and anatomic variations. Genitourinary reconstructive surgeons must have several methods to achieve full-depth vaginoplasty in cases of inadequate genital skin. Peritoneal flaps serve as a versatile, safe, and functionally advantageous solution.

The impact of smoking on sexual function.

OBJECTIVES: To evaluate the hypothesis that there is an improvement in sexual function following smoking cessation (as smoking is a well-established risk factor for sexual dysfunction), we analysed the association between cigarette smoking and smoking cessation with sexual function among participants of the REduction by DUtasteride of prostate Cancer Events (REDUCE) study. SUBJECTS AND METHODS: We analysed baseline data of 6754 men, aged 50-75 years divided into: lifelong non-smokers, former smokers, and current smokers. We examined total testosterone (TT, normal range ≥10 nmol/L) and sexual function variables: self-reported sexual activity, low libido, and erectile dysfunction (ED). Differences between current vs non-smokers and former vs current smokers were analysed using the chi-square test, linear and logistic regressions. RESULTS: A total of 3069 (45.4%) men were non-smokers, 2673 (39.6%) former smokers, and 1012 (15%) current smokers. Current smokers were significantly younger than former and non-smokers (mean age 61.6, 63.2, and 62.7 years, respectively), leaner (mean body mass index 27.0, 27.7, and 27.2 kg/m2 , respectively), and had less hypertension (32.4%, 41.6%, and 36.8%, respectively; all P < 0.01). In uni- and multivariable analysis, current smokers had higher mean TT than non-smokers (485.4 vs 451.2 nmol/L, P < 0.001), higher prevalence of low libido (25.6% vs 21.0%, P = 0.002) and ED (31.6% vs 26.0%, P < 0.001) with comparable sexual activity (81.7% vs 82.8%, P = 0.420). In multivariable analysis, former smokers had statistically significantly less prevalence of low libido (odds ratio [OR] 0.8, P = 0.013) and ED (OR 0.8, P = 0.006) compared to current smokers. CONCLUSION: Cigarette smoking was associated with worse sexual health compared to non-smokers, while former smokers had better erectile function and libido than current smokers. Smoking cessation may improve male sexual health and counselling on smoking cessation may be considered at the time of sexual health evaluations.

PAI-1 is a novel component of the miR-17~92 signaling that regulates pulmonary artery smooth muscle cell phenotypes.

We have previously reported that miR-17~92 is critically involved in the pathogenesis of pulmonary hypertension (PH). We also identified two novel mR-17/20a direct targets, PDZ and LIM domain protein 5 (PDLIM5) and prolyl hydroxylase 2 (PHD2), and elucidated the signaling pathways by which PDLIM5 and PHD2 regulate functions of pulmonary artery smooth muscle cells (PASMCs). In addition, we have shown that plasminogen activator inhibitor-1 (PAI-1) is also downregulated in PASMCs that overexpress miR-17~92. However, it is unclear whether PAI-1 is a direct target of miR-17~92 and whether it plays a role in regulating the PASMC phenotype. In this study, we have identified PAI-1 as a novel target of miR-19a/b, two members of the miR-17~92 cluster. We found that the 3'-untranslated region (UTR) of PAI-1 contains a miR-19a/b binding site and that miR-19a/b can target this site to suppress PAI-1 protein expression. MiR-17/20a, two other members of miR-17~92, may also indirectly suppress PAI-1 expression through PDLIM5. PAI-1 is a negative regulator of miR-17~92-mediated PASMC proliferation. Silencing of PAI-1 induces Smad2/calponin signaling in PASMCs, suggesting that PAI-1 is a negative regulator of the PASMC contractile phenotype. We also found that PAI-1 is essential for the metabolic gene expression in PASMCs. Furthermore, although there is no significant change in PAI-1 levels in PASMCs isolated from idiopathic pulmonary arterial hypertension and associated pulmonary arterial hypertension patients, PAI-1 is downregulated in hypoxia/Sugen-induced hypertensive rat lungs. These results suggest that miR-17~92 regulates the PASMC contractile phenotype and proliferation coordinately and synergistically by direct and indirect targeting of PAI-1.

A High-Throughput Screening Platform Targeting PDLIM5 for Pulmonary Hypertension.

Pulmonary arterial hypertension is a complex disease with multiple etiologic factors. PDLIM5, a member of the Enigma subfamily of PDZ and LIM domain protein family, contains an N-terminal PDZ domain and three LIM domains at its C-terminus. We have previously shown that overexpression of PDLIM5 prevents hypoxia-induced pulmonary hypertension (PH), and deletion of PDLIM5 in smooth muscle cells enhances hypoxia-induced PH in vivo. These results suggest that PDLIM5 may be a novel therapeutic target of PH. In this study, we aim to establish a high-throughput screening platform for PDLIM5-targeted drug discovery. We generated a stable mink lung epithelial cell line (MLEC) containing a transforming growth factor-ß/Smad luciferase reporter with lentivirus-mediated suppression of PDLIM5 (MLEC-shPDLIM5) and measured levels of Smad2/3 and pSmad2/3. We found that in MLEC, suppression of PDLIM5 decreased Smad-dependent luciferase activity, Smad3, and pSmad3. We used MLEC-shPDLIM5 and a control cell line (MLEC-shCTL) to screen the Prestwick library (1200 compounds) and identified and validated paclitaxel as a PDLIM5 inhibitor in MLEC. Furthermore, we showed that paclitaxel inhibited Smad2 expression and Smad3 phosphorylation in A549 cells. Our study suggests that this system is robust and suitable for PDLIM5-targeted drug discovery.

Familial isolated clubfoot is associated with recurrent chromosome 17q23.1q23.2 microduplications containing TBX4.

Clubfoot is a common musculoskeletal birth defect for which few causative genes have been identified. To identify the genes responsible for isolated clubfoot, we screened for genomic copy-number variants with the Affymetrix Genome-wide Human SNP Array 6.0. A recurrent chromosome 17q23.1q23.2 microduplication was identified in 3 of 66 probands with familial isolated clubfoot. The chromosome 17q23.1q23.2 microduplication segregated with autosomal-dominant clubfoot in all three families but with reduced penetrance. Mild short stature was common and one female had developmental hip dysplasia. Subtle skeletal abnormalities consisted of broad and shortened metatarsals and calcanei, small distal tibial epiphyses, and thickened ischia. Several skeletal features were opposite to those described in the reciprocal chromosome 17q23.1q23.2 microdeletion syndrome associated with developmental delay and cardiac and limb abnormalities. Of note, during our study, we also identified a microdeletion at the locus in a sibling pair with isolated clubfoot. The chromosome 17q23.1q23.2 region contains the T-box transcription factor TBX4, a likely target of the bicoid-related transcription factor PITX1 previously implicated in clubfoot etiology. Our result suggests that this chromosome 17q23.1q23.2 microduplication is a relatively common cause of familial isolated clubfoot and provides strong evidence linking clubfoot etiology to abnormal early limb development.