Elevated pigment epithelium-derived factor induces diabetic erectile dysfunction via interruption of the Akt/Hsp90β/eNOS complex

Pigment Epithelium-Derived Factor, a Novel Adipokine, Contributes to Gestational Diabetes Mellitus

CONTEXT

Excessive insulin resistance, inadequate insulin compensation, or both could result in gestational diabetes mellitus (GDM). Levels of pigment epithelium-derived factor (PEDF), a novel adipokine that could induce insulin resistance, are high in patients with obesity and diabetes. However, the impact of PEDF in pregnancy remains unknown.

OBJECTIVE

This study aimed to elucidate the role of PEDF on insulin resistance and compensatory elevation of insulin levels during normal pregnancy and in patients with GDM.

METHODS

In this population-based and cohort study, logistic regression analysis was performed to determine the association of PEDF/adiponectin/leptin levels with the risk of developing GDM and to predict postpartum prediabetes. PEDF protein, PEDF transgenic mice, PEDF knockout mice, and PEDF-neutralized antibodies were used to observe changes in insulin resistance and insulin levels with pregnancy.

RESULTS

Plasma PEDF levels were increased in normal pregnancy and higher in GDM women. Higher PEDF levels were associated with the increased risk of developing GDM and emerged as a significant independent determinant of postpartum prediabetes in GDM women. Mechanistically, in vivo and in vitro experiments revealed that PEDF induced insulin resistance by inhibiting the insulin signaling pathway.

CONCLUSION

In addition to insulin resistance and upregulated insulin levels in normal pregnancy and GDM, aberrant PEDF levels can serve as a "fingerprint" of metabolic abnormalities during pregnancy. Thus, PEDF is a valuable biomarker but could interfere with the time course for early diagnosis and prognosis of GDM.

Methyl protodioscin reduces c-Myc to ameliorate diabetes mellitus erectile dysfunction via downregulation of AKAP12

BACKGROUND

Diabetes mellitus erectile dysfunction (DMED) is one of common complications of diabetes. We aimed to investigate the potential efficacy of methyl protodioscin (MPD) in DMED and explored the underlying mechanism.

METHODS

Diabetic mice were induced by streptozotocin, while vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) were stimulated with high glucose. MPD was administrated in vitro and in vivo to verify its efficacy on DMED. The interaction of c-Myc and AKAP12 was determined by luciferase reporter assay and chromatin immunoprecipitation assay.

RESULTS

c-Myc and AKAP12 were upregulated in penile tissues in DMED mice. In high glucose-stimulated VSMCs or VECs, MPD intervention enhanced cell viability, inhibited apoptosis, decreased c-Myc and AKAP12, as well as elevated p-eNOS Ser1177. MPD-induced apoptosis inhibition, AKAP12 reduction and p-eNOSSer1177 elevation were reversed by AKAP12 overexpression. c-Myc functioned as a positive regulator of AKAP12. Overexpression of c-Myc reversed the effects induced by MPD in vitro, which was neutralized by AKAP12 silencing. MPD ameliorated erectile function in diabetic mice via inhibiting AKAP12.

CONCLUSIONS

MPD improved erectile dysfunction in streptozotocin-caused diabetic mice by regulating c-Myc/AKAP12 pathway, indicating that MPD could be developed as a promising natural agent for the treatment of DMED.

Extracellular Matrix and Protein Phosphorylation Dysregulation Related to Diabetes-Induced Erectile Dysfunction

Diabetes can cause erectile dysfunction (ED) in more than half of male patients. However, the mechanisms underlying diabetes-induced erectile dysfunction (DED) remain unknown. This study is aimed at systematically analyzing the cellular and molecular mechanisms leading to DED using bioinformatic analysis and providing molecular targets for predicting and treating DED. In total, we identified 800 DEGs in the DED samples compared with those in the control group. The 407 upregulated DEGs were mainly enriched in glucose and lipid metabolism-related pathways, and the 393 downregulated DEGs were primarily enriched in tissue development and structure. Dysregulated extracellular matrix genes (especially collagen and elastin) may be closely related to damage to the erectile function of the corpus cavernosum. Sixteen hub genes and 24 modules were detected with hub genes and MCODE analysis. The consensus sequence AAA (G/C) AAA was observed at the promoter sites of most genes that were enriched in the “posttranslational protein phosphorylation” pathway. These genes had abundant phosphorylation sites. Furthermore, 20 TFs targeting DEGs were identified using ChEA3 tool. In conclusion, our research comprehensively and systematically describes the molecular characteristics of DED and suggests that dysregulated extracellular matrix genes and protein phosphorylation may play critical roles in DED. Therefore, they may be potential markers for diagnosing and treating DED.

A comprehensive analysis on the relationship between BDE-209 exposure and erectile dysfunction

Decabromodiphenyl ether (mainly BDE-209) is a commonly used brominated flame retardant in various industrial products. Although its damage to the reproduction system has been established, its effect on erectile function remains unclear. The present study investigated whether BDE-209 induced erectile dysfunction in male SD rats and the underlying mechanisms. Pubertal male rats were exposed to BDE-209 orally (0, 5, 50, and 500 mg/kg/day) for 28 days and the ICP (intracavernous pressure) and MAP (mean arterial pressure) were measured. After the rats were euthanized, the fibrosis and apoptosis levels were evaluated. Additionally, the endothelial function of the rat vascular endothelium cells and the human umbilical vein endothelial cells were impaired after treatment with 50 μM and 100 μM BDE-209. Moreover, the bioinformatics based on CTD database and ChIP-X Enrichment Analysis, version 3 (ChEA3) and molecular docking analysis demonstrated that 5 transcription factors (NFKB1, NR3C1, E2F5, REL, IRF4) might regulate endothelial function by affecting the expression of interactive genes (BCL-2, CAP3, CAT, TNF, MAPK1, and MAPK3). In summary, the present study demonstrated that BDE-209 might affect downstream interactive genes by binding to transcription factors, leading to corpus cavernosum endothelial dysfunction, thus contributing to erectile dysfunction in rats.

The role of microRNAs in erectile dysfunction: From pathogenesis to therapeutic potential

Erectile dysfunction (ED) is a common male sexual dysfunction disease, and it was predicted that the number of ED patients worldwide will reach 322 million by 2025. However, the pathogenesis of ED is complex and the current treatment options are still limited, so it is urgent to explore new treatment strategies. Recent studies have shown that microRNAs (miRNAs) play an important role in ED, and these single-stranded non-coding small RNA molecules are involved in key pathophysiological processes in the occurrence and development of ED. Therefore, miRNAs have remarkable potential as therapeutic targets in ED. Here, this review introduces the physiological basis of erectile function and the pathophysiological changes in ED and summarizes the current knowledge on the expression, biological functions, and molecular mechanisms of miRNAs in ED, especially the potential of miRNA-targeted therapies to improve ED. This review will provide a comprehensive view of the role of miRNAs in the pathogenesis of ED and the potential value of miRNAs in the treatment of ED.

A3 adenosine receptor allosteric modulator CF602 reverses erectile dysfunction in a diabetic rat model

Adenosine plays a major role in erection by binding to its receptors and activating pathways resulting in increased arterial blood flow and intracavernosal pressure (ICP). CF602, an allosteric modulator of the A3 adenosine receptor (A3AR), increases the binding affinity of the endogenous adenosine to the receptor. We examined the effect of CF602 on resolving erectile dysfunction (ED) in a diabetic ED rat model (streptozotocin-induced diabetic rats that were screened for ED using the apomorphine test). ED was assessed by measuring ICP and main arterial pressure (MAP) during electrostimulation of the cavernosal nerve. A single dose of CF602 or placebo was applied either topically (100 μl from a 100 nM or 500 nM solution) or orally (100, 200 or 500 μg/kg) prior to erectile function assessment. A significant dose-dependent improvement in the ICP:MAP ratio without a change in MAP was recorded with the topical and oral CF602 treatments. A significant increase in smooth muscle:collagen ratio, vascular endothelial growth factor and endothelial nitric oxide synthase was also observed in both administration modes. In conclusion, topical and oral treatment with CF602 significantly improved erectile function, supporting its further evaluation as a treatment for ED.

Association between gene polymorphism of inflammatory factors, thrombogenic factors, and stress-related proteins and abdominal aortic aneurysm: A meta-analysis and systematic review

BACKGROUND

Abdominal aortic aneurysm (AAA) is a deadly disease in the elderly population. Currently, the association between single nucleotide polymorphisms (SNPs) and the presence of AAAs has become a hot topic and is a concern for many researchers.

METHOD

We performed a document retrieval in PubMed, EMBASE, and the Cochrane Library (to January 2020). A total of 17 case-control reports on SNPs of AAAs and eight SNPs of correlation factors were selected. All essential data, including race, age, country, criteria of AAA diagnosis, method of AAA measurement, method of genotype detection, name of SNPs, minor allele frequency (MAF), Hardy Weinberg equilibrium (HWE) of the control group, and number of cases and control groups were extracted by two reviewers independently. The fixed-effect model and random-effect model were used to calculate the overall odds ratios (ORs) and 95% confidence intervals (CIs). The association between selected SNPs and the presence of AAAs was evaluated under different genetic models (dominant, codominant, recessive, overdominant, and allele models).

RESULTS

A total of 17 articles (sample size ranging from to 42-665 AAA cases and 49-2,297 controls) and 23 SNPs of related factors were identified. Eight SNPs were assessed in at least two studies and were selected for further meta-analysis. We found that the A allele of interleukin (IL)-10 (-1082 G/A) (OR: 1.35, 95% CI: 1.18-1.54, p < 0.0001) was a risk factor for AAAs under random and fixed-effect models. In addition, partial genetic models of these SNPs were confirmed to be related to the presence of AAA. Subgroup analysis revealed that haptoglobin (HP)-1 was a risk factor for AAAs (OR: 1.30, 95% CI: 1.04-1.63, p = 0.02) in the European population. No association was found between the occurrence of AAA and the other SNPs.

CONCLUSION

In our current meta-analysis, we speculated that the genotype distribution of IL-10 (-1082 G/A) may be associated with the emergence of AAA.

Identification of key genes in type 2 diabetes-induced erectile dysfunction rats with stem cell therapy through high-throughput sequencing and bioinformatic analysis

Diabetes mellitus erectile dysfunction (DMED) is a frequent complication of diabetes. Mesenchymal stem cell (MSC) therapy was demonstrated to improve erectile function in DMED. However, the pathogenesis of DMED and the mechanism by which MSCs function are still unclear. We established a rat model of DMED and gave MSC therapy through intracavernous injection. After transcriptome sequencing of rats' penile tissue, we identified a total of 1,097 overlapped differentially expressed genes (DEGs) of the normal control group, DMED group, and MSC-treated group, containing 189 upregulated genes and 908 downregulated genes. The enriched functions of upregulated DEGs included extracellular matrix organisation (GO:0030198), extracellular structure organisation (GO:0043062), and wound healing (GO:0042060), PPAR signalling pathway (rno03320), arachidonic acid metabolism (rno00590) and retinol metabolism (rno00830). The enriched functions of downregulated DEGs included peptidase activity (GO:0052547), hair follicle development (GO:0001942), intermediate filament-based process (GO:0045103), nitrogen metabolism (rno00910), aldosterone-regulated sodium reabsorption (rno04960) and retinol metabolism (rno00830). We constructed a PPI network with 547 nodes and 2,365 edges and identified 15 hub genes with high connectivity degree. In summary, 15 hub genes with potential roles in the development of ED were identified. Further functional research would be required to elucidate the molecular mechanism underlying misregulated genes.