Microarray analysis reveals novel gene expression changes associated with erectile dysfunction in diabetic rats

Identification of biomarkers for chronic renal fibrosis and their relationship with immune infiltration and cell death

BACKGROUND

Chronic kidney disease (CKD) represents a significant global public health challenge. This study aims to identify biomarkers of renal fibrosis and elucidate the relationship between unilateral ureteral obstruction (UUO), immune infiltration, and cell death.

METHODS

Gene expression matrices for UUO were retrieved from the gene expression omnibus (GSE36496, GSE79443, GSE217650, and GSE217654). Seven genes identified through Protein-Protein Interaction (PPI) network and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) analysis were validated using qRT-PCR in both in vivo and in vitro UUO experiments. WB assays were employed to investigate the role of Clec4n within NF-κB signaling pathway in renal fibrosis. The composition of immune cells in UUO was assessed using CIBERSORT, and gene set variant analysis (GSVA) was utilized to evaluate prevalent signaling pathways and cell death indices.

RESULTS

GO and KEGG enrichment analyses revealed numerous inflammation-related pathways significantly enriched in UUO conditions. Bcl2a1b, Clec4n, and Col1a1 were identified as potential diagnostic biomarkers for UUO. Analysis of immune cell infiltration indicated a correlation between UUO and enhanced mast cell activation. Silencing Clec4n expression appeared to mitigate the inflammatory response in renal fibrosis. GSVA results indicated elevated inflammatory pathway scores in UUO, with significant differences in disulfiram and cuproptosis scores compared to those in the normal murine kidney group.

CONCLUSION

Bcl2a1b, Clec4n, and Col1a1 may serve as biomarkers for diagnosing UUO. UUO development is closely linked to immune cell infiltration, activation of inflammatory pathways, disulfiram, and cuproptosis processes.

Exploring the role of glycolysis in the pathogenesis of erectile dysfunction in diabetes

Background

Diabetes mellitus-related erectile dysfunction (DMED) is characterized by complicated pathogenesis and unsatisfactory therapeutic remedies. Glycolysis plays an essential role in diabetic complications and whether it is involved in the process of DMED has not been expounded. The aim of this study was to investigate the genetic profiling of glycolysis and explore potential mechanisms for DMED.

Methods

Glycolysis-related genes (GRGs) and gene expression matrix of DMED were obtained from the molecular signatures database and gene expression omnibus dataset. Differentially expressed analysis and support vector machine-recursive feature elimination (SVM-RFE) method were both used to obtain hub GRGs. Interactive network and functional enrichment analyses were performed to clarify the associated biological roles of these genes. The expression profile of hub GRGs was validated in cavernous endothelial cells, animals, and clinical patients. The subpopulation distribution of hub GRGs was further identified. In addition, a miRNA-GRGs network was constructed and expression patterns as well as molecular functions of relevant miRNAs were explored and validated. In addition, the relationship between hypoxia and DMED was also uncovered.

Results

Based on the combined analysis, 48 differentially expressed GRGs were obtained. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these genes were significantly enriched in carbon metabolism and oxidoreductase activities. Then hub GRGs including down-regulated as well as up-regulated genes in DMED were identified ultimately. Among them, ALDOC, ANGPTL4, and CITED2 were well-validated. In addition, 334 glycolysis-related miRNAs were verified and they were involved in endoplasmic reticulum membrane activity, smooth muscle cell differentiation and angiogenesis. After validation of miRNA signature in DMED patients, miR-222-5p, let-7e-5p, miR-184, and miR-122-3p were identified as the promising glycolysis-related miRNA biomarkers in DMED.

Conclusions

We clarified the expression signature of GRGs in DMED based on multi-omics analysis for the first time. It will be significantly important to reveal pathological mechanisms and promising treatments in DMED.

MicroRNAs as diagnostic biomarkers in diabetes male infertility: a systematic review

This study conducts an in-depth review of the correlation between testis tissue changes and circulating microRNAs (miRNA) in diabetes-induced male reproductive complications, drawing upon both animal and clinical studies. The original articles published in English that specifically investigate miRNAs linked to male infertility in humans or animals with either type I or ΙΙ diabetes mellitus were included. The relevant articles were gathered from the PubMed, Google Scholar, Cochrane Library, and ScienceDirect databases. The quality of study was assessed utilizing the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Prevalence Studies. We collected an overall number of 1989 citations relating to our research subject. Following the elimination of articles based on the criteria, a total of 20 papers were included in the study. Aberrant expression profiles of 25 miRNAs were identified in diabetes associated with male reproductive issues, with 15 miRNAs exhibiting increased expression and 10 miRNAs showing decreased expression. Among the chosen publications, eighteen were identified as low-risk and two were classed as moderate quality. The dysregulated miRNAs were linked to testicular injury, disrupted steroid production, decreased sperm development and quality, and erectile dysfunction. The results demonstrate that the miRNA-mRNA network is linked to the pathological progression of diabetic testicular damage or erectile dysfunction. From a therapeutic perspective, the identification of circulating miRNAs could be beneficial in the timely identification and prevention of diabetes problems, such as diabetes-induced male infertility. Among all signaling pathways influenced by modified miRNAs, the Bax-caspase-3, MAPK, PI3K-Akt, and eNOS-cGMP-PKC were the main deregulated pathways.

Identification of fibrosis-related genes and biomarkers in diabetic erectile dysfunction

Background

Diabetic erectile dysfunction (DMED) has a high incidence and is poorly treated.

Aim

This study investigates fibrosis's genetic profiling and explores potential mechanisms for DMED.

Methods

The DMED model was constructed in rats using streptozotocin. Erectile function was quantified using cavernous nerve electrostimulation. Fibrosis was evaluated using Masson's staining. RNA-seq was employed to analyze differentially expressed genes and fibrosis-related genes (FRGs) were acquired. Function enrichment analyses were performed, and genetic interaction was analyzed. Hub FRGs were screened using machine learning algorithms and Cytoscape tools and validated in Gene Expression Omnibus databases. Moreover, biological roles and subpopulation distribution of hub FRGs were determined.

Outcomes

Fibrosis-related genetic functions may play a vital role in DMED.

Results

Based on comprehensive analysis, 45 differentially expressed FRGs were identified. These genes participate in regulating smooth muscle cell proliferation, vasoconstriction, and collagen-associated activities. Final analyses identified and validated a core gene signature comprising TIMP1, BMP7, and POSTN. They were closely associated with diabetic complications-related signaling pathways and extracellular matrix-receptor interaction.

Clinical Translation

The identified fibrosis-related gene signature may serve as the novel biomarkers for treating DMED.

Strengths and Limitations

The study is the first to investigate the genetic profiles behind fibrosis and DMED using comprehensive approaches. However, the validation is not adequate and more animal experiments are needed.

Conclusion

The gene profiling and biological functions of FRGs in DMED were identified. These results broaden the understanding of fibrosis in DMED.

M. AQM, Wang X, Tuo Y, Liang X, Xie H, He R, Li G. Nesfatin-1 regulates the phenotype transition of cavernous smooth muscle cells by activating PI3K/AKT/mTOR signaling pathway to improve diabetic erectile dysfunction

OBJECTIVE

This study aims to explore the impact of Nesfatin-1 on type 2 diabetic erectile dysfunction (T2DMED) and its underlying mechanism in regulating the phenotypic switching of corpus cavernosum smooth muscle cells (CCSMCs).

METHODS

Twenty-four 4-week-old male C57 wild-type mice were randomly assigned to the control group, model group, and Nesfatin-1 treatment group. Monitoring included body weight, blood glucose levels, and penile cavernous pressure (ICP). Histochemistry and Western blot analyses were conducted to assess the expressions of α-SMA, OPN, and factors related to the PI3K/AKT/mTOR signaling pathway. CCSMCs were categorized into the control group, high glucose and high oleic acid group (GO group), Nesfatin-1 treatment group (GO+N group), sildenafil positive control group (GO+S group), and PI3K inhibitor group (GO+N+E group). Changes in phenotypic markers, cell morphology, and the PI3K/AKT/mTOR signaling pathway were observed in each group.

RESULTS

(1) Nesfatin-1 significantly ameliorated the body size, body weight, blood glucose, glucose tolerance, and insulin resistance in T2DMED mice. (2) Following Nesfatin-1 treatment, the ICP/MSBP ratio and the peak of the ICP curve demonstrated a significant increase. (3) Nesfatin-1 significantly enhanced smooth muscle and reduced collagen fibers in the corpus cavernosum. (4) Nesfatin-1 notably increased α-SMA expression and decreased OPN expression in CCSMCs. (5) Nesfatin-1 elevated PI3K, p-AKT/AKT, and p-mTOR/mTOR levels in penile cavernous tissue.

CONCLUSIONS

Nesfatin-1 not only effectively improves body weight and blood glucose levels in diabetic mice but also enhances erectile function and regulates the phenotypic switching of corpus cavernosum smooth muscle. The potential mechanism involves Nesfatin-1 activating the PI3K/AKT/mTOR signaling pathway to induce the conversion of CCSMCs to a contractile phenotype.

Comprehensive analysis of biological landscape of oxidative stress-related genes in diabetic erectile dysfunction

Oxidative stress plays a pivotal role in the pathogenesis of diabetic erectile dysfunction, while specific mechanisms have not been illuminated. The study aims to reveal the genetic expression patterns of oxidative stress in diabetic erectile dysfunction. Transcriptome data of diabetic erectile dysfunction and oxidative stress-related genes (OSRGs) in the Gene Expression Omnibus database were downloaded and analyzed based on differential expression. Functional enrichment analyses were conducted to clarify the biological functions. A protein interaction framework was established, and significant gene profiles were validated in the cavernous endothelial cells, clinical patients, and rat models. A miRNA-OSRGs network was predicted and validated. The results were analyzed using Student's t-test. The analysis screened 203 differentially expressed OSRGs (p < 0.05), which had a close association with oxidoreductase activities, glutathione metabolism, and autophagy. A four-gene signature comprised of EPS8L2 (p = 0.044), GSTA3 (p = 0.015), LOX (p < 0.001) and MGST1 (p = 0.002) was well validated and regarded as the hub OSRGs. Compared with the control group, notable increases and decreases were observed in the expressions of GSTA3 (3.683 ± 0.636 vs. 0.416 ± 0.507) and LOX (2.104 ± 1.895 vs. 18.804 ± 2.751) in the validated diabetic erectile dysfunction group. The hub OSRGs-related miRNAs participated in smooth muscle cell proliferation. Besides, miR-125a-3p (p = 0.034) and miR-138-2-3p (p = 0.012) were validated as promising oxidative stress-related miRNA biomarkers. Our findings revealed the genetic alternations of oxidative stress in diabetic erectile dysfunction. These results will be instructive to explore the molecular landscape and the potential treatment for diabetic erectile dysfunction.

Nesfatin-1 regulates the phenotype transition of cavernous smooth muscle cells by activating PI3K/AKT/mTOR signaling pathway to improve diabetic erectile dysfunction

Objective

This study aims to explore the impact of Nesfatin-1 on type 2 diabetic erectile dysfunction (T2DMED) and its underlying mechanism in regulating the phenotypic switching of corpus cavernosum smooth muscle cells (CCSMCs).

Methods

Twenty-four 4-week-old male C57 wild-type mice were randomly assigned to the control group, model group, and Nesfatin-1 treatment group. Monitoring included body weight, blood glucose levels, and penile cavernous pressure (ICP). Histochemistry and Western blot analyses were conducted to assess the expressions of α-SMA, OPN, and factors related to the PI3K/AKT/mTOR signaling pathway. CCSMCs were categorized into the control group, high glucose and high oleic acid group (GO group), Nesfatin-1 treatment group (GO + N group), sildenafil positive control group (GO + S group), and PI3K inhibitor group (GO + N + E group). Changes in phenotypic markers, cell morphology, and the PI3K/AKT/mTOR signaling pathway were observed in each group.

Results

(1) Nesfatin-1 significantly ameliorated the body size, body weight, blood glucose, glucose tolerance, and insulin resistance in T2DMED mice. (2) Following Nesfatin-1 treatment, the ICP/MSBP ratio and the peak of the ICP curve demonstrated a significant increase. (3) Nesfatin-1 significantly enhanced smooth muscle and reduced collagen fibers in the corpus cavernosum. (4) Nesfatin-1 notably increased α-SMA expression and decreased OPN expression in CCSMCs. (5) Nesfatin-1 elevated PI3K, p-AKT/AKT, and p-mTOR/mTOR levels in penile cavernous tissue.

Conclusions

Nesfatin-1 not only effectively improves body weight and blood glucose levels in diabetic mice but also enhances erectile function and regulates the phenotypic switching of corpus cavernosum smooth muscle. The potential mechanism involves Nesfatin-1 activating the PI3K/AKT/mTOR signaling pathway to induce the conversion of CCSMCs to a contractile phenotype.

Single-cell transcriptome analysis of cavernous tissues reveals the key roles of pericytes in diabetic erectile dysfunction

Erectile dysfunction (ED) affects a significant proportion of men aged 40-70 and is caused by cavernous tissue dysfunction. Presently, the most common treatment for ED is phosphodiesterase 5 inhibitors; however, this is less effective in patients with severe vascular disease such as diabetic ED. Therefore, there is a need for development of new treatment, which requires a better understanding of the cavernous microenvironment and cell-cell communications under diabetic condition. Pericytes are vital in penile erection; however, their dysfunction due to diabetes remains unclear. In this study, we performed single-cell RNA sequencing to understand the cellular landscape of cavernous tissues and cell type-specific transcriptional changes in diabetic ED. We found a decreased expression of genes associated with collagen or extracellular matrix organization and angiogenesis in diabetic fibroblasts, chondrocytes, myofibroblasts, valve-related lymphatic endothelial cells, and pericytes. Moreover, the newly identified pericyte-specific marker, Limb Bud-Heart (Lbh), in mouse and human cavernous tissues, clearly distinguishing pericytes from smooth muscle cells. Cell-cell interaction analysis revealed that pericytes are involved in angiogenesis, adhesion, and migration by communicating with other cell types in the corpus cavernosum; however, these interactions were highly reduced under diabetic conditions. Lbh expression is low in diabetic pericytes, and overexpression of LBH prevents erectile function by regulating neurovascular regeneration. Furthermore, the LBH-interacting proteins (Crystallin Alpha B and Vimentin) were identified in mouse cavernous pericytes through LC-MS/MS analysis, indicating that their interactions were critical for maintaining pericyte function. Thus, our study reveals novel targets and insights into the pathogenesis of ED in patients with diabetes.

BMP4 and GREM1 are targets of SHH signaling and downstream regulators of collagen in the penis

BACKGROUND

Cavernous nerve (CN) injury, caused by prostatectomy and diabetes, initiates a remodeling process (smooth muscle apoptosis and increased collagen) in the corpora cavernosa of the penis of patients and animal models that is an underlying cause of erectile dysfunction (ED), and the Sonic hedgehog (SHH) pathway plays an essential role in the response of the penis to denervation, as collagen increases with SHH inhibition and decreases with SHH treatment.

AIM

We examined if part of the mechanism of how SHH prevents penile remodeling and increased collagen with CN injury involves bone morphogenetic protein 4 (BMP4) and gremlin1 (GREM1) and examined the relationship between SHH, BMP4, GREM1, and collagen in penis of ED patients and rat models of CN injury, SHH inhibition, and SHH, BMP4, and GREM1 treatment.

METHODS

Corpora cavernosa of Peyronie's disease (control), prostatectomy, and diabetic ED patients were obtained (N = 30). Adult Sprague Dawley rats (n = 90) underwent (1) CN crush (1-7 days) or sham surgery; (2) CN injury and BMP4, GREM1, or mouse serum albumin (control) treatment via Affi-Gel beads or peptide amphiphile (PA) for 14 days; (3) 5E1 SHH inhibitor, IgG, or phosphate-buffered saline (control) treatment for 2 to 4 days; or (4) CN crush with mouse serum albumin or SHH for 9 days.

OUTCOMES

Immunohistochemical and Western analysis for BMP4 and GREM1, and collagen analysis by hydroxyproline and trichrome stain were performed.

RESULTS

BMP4 and GREM1 proteins were identified in corpora cavernosa smooth muscle of prostatectomy, diabetic, and Peyronie's patients, and in rat smooth muscle, sympathetic nerve fibers, perineurium, blood vessels, and urethra. Collagen decreased 25.4% in rats with CN injury and BMP4 treatment (P = .02) and increased 61.3% with CN injury and GREM1 treatment (P = .005). Trichrome stain showed increased collagen in rats treated with GREM1. Western analysis identified increased BMP4 and GREM1 in corpora cavernosa of prostatectomy and diabetic patients, and after CN injury (1-2 days) in our rat model. Localization of BMP4 and GREM1 changed with SHH inhibition. SHH treatment increased the monomer form of BMP4 and GREM1, altering their range of signaling.

CLINICAL IMPLICATIONS

A better understanding of penile remodeling and how fibrosis occurs with loss of innervation is essential for development of novel ED therapies.

STRENGTHS AND LIMITATIONS

The relationship between SHH, BMP4, GREM1, and collagen is complex in the penis.

CONCLUSION

BMP4 and GREM1 are downstream targets of SHH that impact collagen and may be useful in collaboration with SHH to prevent penile remodeling and ED.

SHH regulates penile morphology and smooth muscle through a mechanism involving BMP4 and GREM1

BACKGROUND

The cavernous nerve (CN) is frequently damaged in prostatectomy and diabetic patients with erectile dysfunction (ED), initiating changes in penile morphology including an acute and intense phase of apoptosis in penile smooth muscle and increased collagen, which alter penile architecture and make corpora cavernosa smooth muscle less able to relax in response to neurotransmitters, resulting in ED.

AIM

Sonic hedgehog (SHH) is a critical regulator of penile smooth muscle, and SHH treatment suppresses penile remodeling after CN injury through an unknown mechanism; we examine if part of the mechanism of how SHH preserves smooth muscle after CN injury involves bone morphogenetic protein 4 (BMP4) and gremlin1 (GREM1).

METHODS

Primary cultures of smooth muscle cells were established from prostatectomy, diabetic, hypertension and Peyronie's (control) (N = 18) patients. Cultures were characterized by ACTA2, CD31, P4HB, and nNOS immunohistochemical analysis. Patient smooth muscle cell growth was quantified in response to BMP4 and GREM1 treatment. Adult Sprague Dawley rats underwent 1 of 3 surgeries: (1) uninjured or CN-injured rats were treated with BMP4, GREM1, or mouse serum albumin (control) proteins via Affi-Gel beads (N = 16) or peptide amphiphile (PA) (N = 26) for 3 and 14 days, and trichrome stain was performed; (2) rats underwent sham (N = 3), CN injury (N = 9), or CN injury and SHH PA treatment for 1, 2, and 4 days (N = 9).

OUTCOMES

Western analysis for BMP4 and GREM1 was performed; (3) rats were treated with 5E1 SHH inhibitor (N = 6) or IgG (control; N = 6) for 2 and 4 days, and BMP4 and GREM1 localization was examined. Statistics were performed by analysis of variance with Scheffé's post hoc test.

RESULTS

BMP4 increased patient smooth muscle cell growth, and GREM1 decreased growth. In rats, BMP4 treatment via Affi-Gel beads and PA increased smooth muscle at 3 and 14 days of treatment. GREM1 treatment caused increased collagen and smooth muscle at 3 days, which switched to primarily collagen at 14 days. CN injury increased BMP4 and GREM1, while SHH PA altered Western band size, suggesting alternative cleavage and range of BMP4 and GREM1 signaling. SHH inhibition in rats increased BMP4 and GREM1 in fibroblasts.

CLINICAL IMPLICATIONS

Understanding how SHH PA preserves and regenerates penile morphology after CN injury will aid development of ED therapies.

STRENGTHS AND LIMITATIONS

SHH treatment alters BMP4 and GREM1 localization and range of signaling, which can affect penile morphology.

CONCLUSION

Part of the mechanism of how SHH regulates corpora cavernosa smooth muscle involves BMP4 and GREM1.

Allograft inflammatory factor-1 enhances inflammation and oxidative stress via the NF-κB pathway of bladder urothelium in diabetic rat model

OBJECTIVES

To explore the role of allograft inflammatory factor-1 (AIF-1) both in diabetic rat bladder urothelium and in high-glucose-treated human urothelial cell line (SV-HUC-1).

METHODS

Inflammation and oxidative stress (OS) promote diabetic cystopathy (DCP), but the mechanisms are not fully understood. The expression level of AIF-1 in diabetic rat bladder urothelium and in the SV-HUC-1 cells treated with high glucose was detected using tissue immunofluorescence, immunohistochemistry and western blot assays. AIF-1 was knocked down and NF-κB was suppressed with the specific inhibitor BAY 11-7082 in high-glucose-treated SV-HUC-1 cells.

RESULTS

High-glucose condition induced AIF-1 upregulation in vivo and in vitro. The up-regulated AIF-1 induced the production of inflammatory factors IL-6 and TNF-α and elevation of ROS. Informatics analysis suggested that NF-κB pathway is implicated in DCP. Through knockdown of AIF-1, we confirmed that AIF-1 simulated NF-κB pathway by enhancing the phosphorylation of IκB (p-IκB) and promoting the translocation of NF-κB p65 from cytoplasm into nucleus. Additionally, High-glucose-induced inflammation in SV-HUC-1 cells was attenuated by the addition of NF-κB inhibitor.

CONCLUSIONS

This study provides novel information to understand the molecular regulation mechanisms of AIF-1 in DCP.

Exploring potential genes and mechanisms linking erectile dysfunction and depression

Background

The clinical correlation between erectile dysfunction (ED) and depression has been revealed in cumulative studies. However, the evidence of shared mechanisms between them was insufficient. This study aimed to explore common transcriptomic alterations associated with ED and depression.

Materials and methods

The gene sets associated with ED and depression were collected from the Gene Expression Omnibus (GEO) database. Comparative analysis was conducted to obtain common genes. Using R software and other appropriate tools, we conducted a range of analyses, including function enrichment, interactive network creation, gene cluster analysis, and transcriptional and post-transcriptional signature profiling. Candidate hub crosslinks between ED and depression were selected after external validation and molecular experiments. Furthermore, subpopulation location and disease association of hub genes were explored.

Results

A total of 85 common genes were identified between ED and depression. These genes strongly correlate with cell adhesion, redox homeostasis, reactive oxygen species metabolic process, and neuronal cell body. An interactive network consisting of 80 proteins and 216 interactions was thereby developed. Analysis of the proteomic signature of common genes highlighted eight major shared genes: CLDN5, COL7A1, LDHA, MAP2K2, RETSAT, SEMA3A, TAGLN, and TBC1D1. These genes were involved in blood vessel morphogenesis and muscle cell activity. A subsequent transcription factor (TF)-miRNA network showed 47 TFs and 88 miRNAs relevant to shared genes. Finally, CLDN5 and TBC1D1 were well-validated and identified as the hub crosslinks between ED and depression. These genes had specific subpopulation locations in the corpus cavernosum and brain tissue, respectively.

Conclusion

Our study is the first to investigate common transcriptomic alterations and the shared biological roles of ED and depression. The findings of this study provide insights into the referential molecular mechanisms underlying the co-existence between depression and ED.

Differential Gene Expression in the Penile Cavernosum of Streptozotocin-Induced Diabetic Rats

PURPOSE

Men with diabetes mellitus (DM) often present with severe erectile dysfunction (ED). This ED is less responsive to current pharmacological therapies. If we know the upregulated or downregulated genes of diabetic ED, we can inhibit or enhance the expression of such genes through RNA or gene overexpression.

METHODS

To investigate gene changes associated with ED in type 1 DM, we examined the alterations of gene expression in the cavernosum of streptozotocin-induced diabetic rats. Specifically, we considered 11,636 genes (9,623 upregulated and 2,013 downregulated) to be differentially expressed in the diabetic rat cavernosum group (n=4) compared to the control group (n=4). The analysis of differentially expressed genes using the gene ontology (GO) classification indicated that the following were enriched: downregulated genes such as cell cycle, extracellular matrix, glycosylphosphatidylinositol-anchor biosynthesis and upregulated genes such as calcium signaling, neurotrophin signaling, apoptosis, arginine and proline metabolism, gap junction, transforming growth factor-β signaling, tight junction, vascular smooth muscle contraction, and vascular endothelial growth factor (VEGF) signaling. We examined a more than 2-fold upregulated or downregulated change in expression, using real time polymerase chain reaction. Analysis of differentially expressed genes, using the GO classification, indicated the enrichment.

RESULTS

Of the 41,105 genes initially considered, statistical filtering of the array analysis showed 9,623 upregulated genes and 2,013 downregulated genes with at least 2-fold changes in expression (P<0.05). With Bonferroni correction, SLC2A9 (solute carrier family 2 member 9), LRRC20 (leucine rick repeat containing 20), PLK1 (polo like kinase 1), and AATK (apoptosis-associated tyrosine kinase) were all 2-fold changed genes.

CONCLUSION

This study broadens the scope of candidate genes that may be relevant to the pathophysiology of diabetic ED. In particular, their enhancement or inhibition could represent a novel treatment for diabetic ED.

Identifying potential cross-talk signatures for the occurrence of atherosclerosis in diabetic erectile dysfunction

BACKGROUND

Erectile dysfunction and atherosclerosis are common cardiovascular complications in diseases. Clinical associations between erectile dysfunction and atherosclerosis have been noticed, but the specific mechanisms are not illustrated adequately.

OBJECTIVES

The aim of the study was to further mine associated pathological mechanisms and genetic alterations of atherosclerosis in diabetes mellitus-related erectile dysfunction.

MATERIALS AND METHODS

Significant atherosclerosis-related genes were identified from transcriptome data of diabetes mellitus-related erectile dysfunction and atherosclerosis-related gene sets from DisGeNET and GeneCard databases. Functional enrichment and immune infiltration analyses were performed to clarify the biological roles and pathways as well as immune responses of significant atherosclerosis-related gene sets. A protein-protein interaction network was constructed, and gene clusters were performed. Then, data of diabetic plaques and high-glucose cavernosum endothelial cells were analyzed for validation. And hub atherosclerosis-related gene sets were identified. Finally, expressed pattern of hub atherosclerosis-related gene sets were explored by single-cell profiling and immune analysis.

RESULTS

In total, 202 significant atherosclerosis-related gene sets including 100 upregulated and 102 downregulated genes were identified. These genes were related to endothelial cell migration, inflammatory response, regulation of oxidative stress, and immune response. In immune infiltration, immature dendritic cells and monocytes showed differential expression between the diabetes mellitus-related erectile dysfunction and control groups, A protein-protein interaction network containing 135 nodes was constructed. A hub atherosclerosis-related gene set signature consisting of HBEGF, LOX, NQO1, and VLDLR was obtained by multi-omics validation. In addition, Functional enrichment analysis revealed that hub atherosclerosis-related gene sets were involved in oxidoreductase activity and extracellular matrix organization.

DISCUSSION AND CONCLUSION

We explored atherosclerosis-related genetic changes and signaling pathways in diabetes mellitus-related erectile dysfunction. HBEGF, LOX, NQO1, and VLDLR were identified as hub atherosclerosis-related gene sets. These may serve as potential biomarkers for the clinical management of atherosclerosis and preventing further cardiovascular risks in diabetes mellitus-related erectile dysfunction.

The genetic associations of COVID-19 on genitourinary symptoms

Background

Recently emerged reports indicated that patients with coronavirus disease 2019 (COVID-19) might experience novo genitourinary symptoms after discharge. Nevertheless, the causal associations and underlying mechanisms remain largely unclear.

Methods

Genome-wide association study (GWAS) statistics for COVID-19 and 28 genitourinary symptoms with consistent definitions were collected from the COVID-19 Host Genetic Initiative, FinnGen, and UK Biobanks. Mendelian randomization (MR) analyses were applied to explore the causal effects of COVID-19 on genitourinary symptoms by selecting single-nucleotide polymorphisms as instrumental variables. Meta-analyses were conducted to evaluate the combined causal effect. Molecular pathways connecting COVID-19 and its associated disorders were evaluated by weighted gene co-expression network analysis (WGCNA) and enrichment analyses to extract insights into the potential mechanisms underlying the connection.

Results

The MR and meta-analyses indicated that COVID-19 was causally associated with increased risk for calculus of the lower urinary tract (LUTC, OR: 1.2984 per doubling in odds of COVID-19, 95% CI: 1.0752-1.5680, p = 0.007) and sexual dysfunction (SD, OR: 1.0931, 95% CI: 1.0292-1.1610, p = 0.004). Intriguingly, COVID-19 might exert a slight causal protective effect on the progression of urinary tract infections (UTIs) and bladder cancer (BLCA). These results were robust to sensitivity analyses. Bioinformatic analyses indicated that the inflammatory-immune response module may mediate the links between COVID-19 and its associated disorders at the molecular level.

Conclusions

In response to post-COVID-19 symptoms, we recommend that COVID-19 patients should strengthen the prevention of LUTC and the monitoring of sexual function. Meanwhile, the positive effects of COVID-19 on UTIs and BLCA should attach equal importance.

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.

Uncovering the genetic links of diabetic erectile dysfunction and chronic prostatitis/chronic pelvic pain syndrome

Background: Clinical associations between erectile dysfunction and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) have been noticed, but the common pathogenic mechanisms between them remain elusive. The aim of the study was to mine shared genetic alterations between ED and chronic prostatitis/chronic pelvic pain syndrome. Method: Transcriptome data of ED and chronic prostatitis/chronic pelvic pain syndrome-related genes (CPRGs) were retrieved from relevant databases and differentially expressed analysis was used to obtain significant CPRGs. Then function enrichment and interaction analyses were performed to show shared transcriptional signature, including gene ontology and pathway enrichment, the construction of protein-protein interaction (PPI) network, cluster analysis, and co-expression analysis. Hub CPRGs and key cross-link were selected by validating these genes in clinical samples, chronic prostatitis/chronic pelvic pain syndrome and ED-related datasets. Then the miRNA-OSRGs co-regulatory network was predicted and validated. Subpopulation distribution and disease association of hub CPRGs were further identified. Result: Differentially expressed analysis revealed 363 significant CPRGs between ED and chronic prostatitis/chronic pelvic pain syndrome, functioning in inflammatory reaction, oxidative stress, apoptosis, smooth muscle cell proliferation, and extracellular matrix organization. A PPI network containing 245 nodes and 504 interactions was constructed. Module analysis depicted that multicellular organismal process and immune metabolic process were enriched. 17 genes were screened in PPI via topological algorithms, and reactive oxygen species as well as interleukin-1 metabolism were regarded as the bridging interactive mechanism. After screening and validation, a hub-CPRG signature consisting of COL1A1, MAPK6, LPL, NFE2L2 and NQO1 were identified and associated miRNA were verified. These miRNAs played an important role in immune and inflammatory response likewise. Finally, NQO1 was identified as a key genetic link between ED and chronic prostatitis/chronic pelvic pain syndrome. It was predominately enriched in corpus cavernosum endothelial cell, and correlated with other male urogenital and immune system diseases tightly. Conclusion: We identified the genetic profiles as well as corresponding regulatory network underlying interaction between ED and chronic prostatitis/chronic pelvic pain syndrome via multi-omics analysis. These findings expanded a new understanding for the molecular mechanism of ED with chronic prostatitis/chronic pelvic pain syndrome.

Identification of hub biomarkers and exploring the roles of immunity, M6A, ferroptosis, or cuproptosis in rats with diabetic erectile dysfunction

BACKGROUND

Currently, patients with diabetic erectile dysfunction (DMED) were not satisfied with the effects of first-line phosphodiesterase type 5 inhibitors (PDE5Is). Hence, this paper was designed to mine hub biomarkers in DMED and explore its potential mechanisms.

METHODS

Gene expression matrix of DMED was downloaded from the gene expression omnibus (GEO; GSE2457) dataset. The top 20 genes were selected based on the connectivity degrees in protein-protein interaction (PPI) network. Functional enrichment analysis was utilized to reveal DMED-related signaling pathways. We also explored the roles of immunity, m6A, ferroptosis, or cuproptosis in DMED and constructed Sprague Dawley (SD) rats DMED model to verify gene expressions by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Based on the threshold, a total of 122 differently expressed genes (DEGs) were identified in DMED, including 39 up-regulated and 83 down-regulated genes. Functional enrichment analysis implied that these DEGs were significantly enriched in peroxisome proliferator-activated receptors, ferroptosis, hypoxia-inducible factor 1 signaling pathways, and so on. SD rats DMED model was also successfully established by us and validated by intracavernous pressure/mean arterial pressure, Masson's trichrome staining, and immunohistochemical analysis. We further verified the expression of these top 20 genes from the PPI network by qRT-PCR in the SD rats DMED model and finally identified Sparc, Lox, Srebf1, and Mmp3 as hub biomarkers (all p < 0.05). As for immunity and cuproptosis, our analysis indicated that DMED had nothing to do with them (all p > 0.05). Actually, DMED was markedly associated with m6A regulators and ferroptosis.

CONCLUSIONS

We identified Sparc, Lox, Srebf1, and Mmp3 as potential hub biomarkers in the SD rats DMED model for future drug development and found its significant associations with m6A regulators and ferroptosis, but not with immunity or cuproptosis.

Potential role of oxidative stress in the pathogenesis of diabetic bladder dysfunction

Diabetes mellitus is a chronic metabolic disease, posing a considerable threat to global public health. Treating systemic comorbidities has been one of the greatest clinical challenges in the management of diabetes. Diabetic bladder dysfunction, characterized by detrusor overactivity during the early stage of the disease and detrusor underactivity during the late stage, is a common urological complication of diabetes. Oxidative stress is thought to trigger hyperglycaemia-dependent tissue damage in multiple organs; thus, a growing body of literature has suggested a possible link between functional changes in urothelium, muscle and the corresponding innervations. Improved understanding of the mechanisms of oxidative stress could lead to the development of novel therapeutics to restore the redox equilibrium and scavenge excessive free radicals to normalize bladder function in patients with diabetes.

Identification of Key microRNAs in Diabetes Mellitus Erectile Dysfunction Rats with Stem Cell Therapy by Bioinformatic Analysis of Deep Sequencing Data

PURPOSE

Diabetes mellitus erectile dysfunction (DMED) is a common resulting complication of diabetes. Studies have shown mesenchymal stem cell (MSC)-based therapy was beneficial in alleviating erectile function of DMED rats. While the pathogenesis of DMED and the mechanism MSCs actions are unclear.

MATERIALS AND METHODS

We constructed a rat model of DMED with or without intracavernous injection of MSCs, and performed microRNA (miRNA) sequencing of corpora cavernosa tissues.

RESULTS

We identified three overlapping differentially expressed miRNAs (rno-miR-1298, rno-miR-122-5p, and rno-miR-6321) of the normal control group, DMED group, and DMED+MSCs group. We predicted 285 target genes of three miRNAs through RNAhybrid and miRanda database and constructed a miRNA-target gene network through Cytoscape. Next, we constructed protein-protein interaction networks through STRING database and identified the top 10 hub genes with highest connectivity scores. Five GO terms including cellular response to growth factor stimulus (GO:0071363), ossification (GO:0001503), response to steroid hormone (GO:0048545), angiogenesis (GO:0001525), positive regulation of apoptotic process (GO:0043065), and one Reactome pathway (Innate Immune System) were significantly enriched by 10 hub genes using the Metascape database. We selected the GSE2457 dataset to validate the expression of hub genes and found only the expression of B4galt1 was statistically different (p<0.001). B4galt1 was highly expressed in penile tissues of diabetic rats and would be negatively regulated by rno-miR-1298.

CONCLUSIONS

Three key miRNAs were identified in DMED rats with stem cell therapy and the miR-1298/B4GalT1 axis might exert function in stem cell therapy for ED.

Pathway Enrichment Analysis of Microarray Data Fom Human Penis of Diabetic and Peyronie's Patients, in Comparison with Diabetic Rat Erectile Dysfunction Models

BACKGROUND

Erectile dysfunction (ED) is a debilitating medical condition in which current treatments are minimally effective in diabetic patients due to neuropathy of the cavernous nerve, a peripheral nerve that innervates the penis. Loss of innervation causes apoptosis of penile smooth muscle, remodeling of corpora cavernosa (penile erectile tissue) morphology, and ED.

AIM

In this study, microarray and pathway analysis were used to obtain a global understanding of how signaling mechanisms are altered in diabetic patients and animal models as ED develops, in order to identify novel targets for disease management, and points of intervention for clinical therapy development.

METHODS AND OUTCOMES

Human corpora cavernosal tissue was obtained from diabetic (n = 4) and Peyronie's (control, n = 3) patients that were undergoing prosthesis implant to treat ED, and BB/WOR diabetic (n = 5) and resistant (n = 5) rats. RNA was extracted using TRIzol, DNase treated, and purified by Qiagen mini kit. Microarray was performed using the Human Gene 2.0 ST Array. (i) Alterations in patient and diabetic rat pathway signaling were examined using several analytical tools (ShinyGO, Metascape, WebGestalt, STRING) and databases, (ii) Strengths/weaknesses of the different pathway analysis tools were compared, and (iii) Comparison of human and rat (BB/WOR and Streptozotocin) pathway analysis was performed. Two technical replicates were performed. P value (FDR) < .15 was used as threshold for differential expression. FDR < 0.05 was considered significant.

RESULTS

Microarray identified 182 differentially expressed protein-coding genes. Pathway analysis revealed similar enrichments with different analytical tools. Down regulated pathways include development, tubular structure, sprouting, cell death, ischemia, angiogenesis, transcription, second messengers, and stem cell differentiation. ED patients, who have diabetes, incur significant loss of normal regulatory processes required for repair and replacement of injured corpora cavernosal tissue. Combined with loss of apoptotic regulatory mechanisms, this results in significant architectural remodeling of the corpora cavernosa, and loss of regenerative capacity in the penis.

CLINICAL TRANSLATION

This first report of microarray and pathway analysis in human corpora cavernosa, is critical for identification of novel pathways pertinent to ED and for validating animal models.

STRENGTHS AND LIMITATIONS

The analysis of tissue specific gene expression profiles provides a means of understanding drivers of disease and identifying novel pathways for clinical intervention.

CONCLUSION

Penis from diabetic ED patients lacks capacity for maintenance of corpora cavernosal architecture and regeneration, which are critical points for intervention for therapy development.

Tetrathiomolybdate Partially Alleviates Erectile Dysfunction of Type 1 Diabetic Rats Through Affecting Ceruloplasmin/eNOS and Inhibiting Corporal Fibrosis and Systemic Inflammation

INTRODUCTION

Patients with erectile dysfunction induced by diabetes mellitus (DMED) show a poor effect rate for oral phosphodiesterase type 5 inhibitors (PDE5is). Therefore, the new therapeutic strategy is necessary in patients with DMED.

AIM

To investigate whether Tetrathiomolybdate (TM) supplementation could ameliorate DMED by activation of eNOS.

METHODS

Twenty-four diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ) and the other 6 normal rats constituted the control group. Eight weeks later, the erectile function of rats was assessed with an apomorphine test. Only some rats with DMED were treated with TM orally every day for 4 weeks; the other rats remained in the same condition for 4 weeks. After 1 week washout, the erectile function of rats in each group was evaluated. Then, the serum concentration of IL-6 and histologic changes of corpus cavernosum were measured.

MAIN OUTCOME MEASURE

Erectile function was measured after DMED rats treated with TM. The cavernosum level of Ceruloplasmin (Cp), eNOS, endothelial cell content, corporal fibrosis, apoptosis rate and the serum level of IL-6 were also assayed.

RESULTS

Erectile function in the DMED group was significantly impaired compared with the control group and was partly, but significantly, improved in the DMED+TM group. The DMED group showed upregulation of Cp and inhibition of eNOS, but the inhibition was partly reversed in the DMED+TM group. The DMED group showed serious corporal fibrosis. However, TM supplementation partly increased the ratio of smooth muscle to collagen, decreased the ratio of apoptosis. What's more, gavage administration of TM profoundly decreased the serum level of IL-6 in DMED rats.

CONCLUSION

TM supplementation inhibits endothelial dysfunction, corporal fibrosis, and systemic inflammation, ultimately leading to partial improvement of DMED in rats. Yin Y, Peng J, Zhou J, et al., Tetrathiomolybdate Partially Alleviates Erectile Dysfunction of Type 1 Diabetic Rats Through Affecting Ceruloplasmin/eNOS and Inhibiting Corporal Fibrosis and Systemic Inflammation. Sex Med 2021;XX:XXXXXX.

Comparison of critical biomarkers in 2 erectile dysfunction models based on GEO and NOS-cGMP-PDE5 pathway

BACKGROUND

Erectile dysfunction is a disease commonly caused by diabetes mellitus (DMED) and cavernous nerve injury (CNIED). Bioinformatics analyses including differentially expressed genes (DEGs), enriched functions and pathways (EFPs), and protein-protein interaction (PPI) networks were carried out in DMED and CNIED rats in this study. The critical biomarkers that may intervene in nitric oxide synthase (NOS, predominantly nNOS, ancillary eNOS, and iNOS)-cyclic guanosine monophosphate (cGMP)-phosphodiesterase 5 enzyme (PDE5) pathway, an important mechanism in erectile dysfunction treatment, were then explored for potential clinical applications.

METHODS

GSE2457 and GSE31247 were downloaded. Their DEGs with a |logFC (fold change)| > 0 were screened out. Database for Annotation, Visualization and Integrated Discovery (DAVID) online database was used to analyze the EFPs in Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes networks based on down-regulated and up-regulated DEGs respectively. PPI analysis of 2 datasets was performed in Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape. Interactions with an average score greater than 0.9 were chosen as the cutoff for statistical significance.

RESULTS

From a total of 1710 DEGs in GSE2457, 772 were down-regulated and 938 were up-regulated, in contrast to the 836 DEGs in GSE31247, from which 508 were down-regulated and 328 were up-regulated. The 25 common EFPs such as aging and response to hormone were identified in both models. PPI results showed that the first 10 hub genes in DMED were all different from those in CNIED.

CONCLUSIONS

The intervention of iNOS with the hub gene complement component 3 in DMED and the aging process in both DMED and CNIED deserves attention.

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.

Gene expression profiling of mouse cavernous endothelial cells for diagnostic targets in diabetes-induced erectile dysfunction

PURPOSE

To investigate potential target genes associated with the diabetic condition in mouse cavernous endothelial cells (MCECs) for the treatment of diabetes-induced erectile dysfunction (ED).

MATERIALS AND METHODS

Mouse cavernous tissue was embedded into Matrigel, and sprouted cells were subcultivated for other studies. To mimic diabetic conditions, MCECs were exposed to normal-glucose (NG, 5 mmoL) or high-glucose (HG, 30 mmoL) conditions for 72 hours. An RNA-sequencing assay was performed to evaluate gene expression profiling, and RT-PCR was used to validate the sequencing data.

RESULTS

We isolated MCECs exposed to the two glucose conditions. MCECs showed well-organized tubes and dynamic migration in the NG condition, whereas tube formation and migration were significantly decreased in the HG condition. RNA-sequencing analysis showed that MCECs had different gene profiles in the NG and HG conditions. Among the significantly changed genes, which we classified into 14 major gene categories, we identified that aging-related (9.22%) and angiogenesis-related (9.06%) genes were changed the most. Thirteen genes from the two gene categories showed consistent changes on the RNA-sequencing assay, and these findings were validated by RT-PCR.

CONCLUSIONS

Our gene expression profiling studies showed that Cyp1a1, Gclm, Igfbp5, Nqo1, Il6, Cxcl5, Olr1, Ctgf, Hbegf, Serpine1, Cyr61, Angptl4, and Loxl2 may play a critical role in diabetes-induced ED through aging and angiogenesis signaling. Additional research is necessary to help us understand the potential mechanisms by which these genes influence diabetes-induced ED.

Gene expression profile comparison in the penile tissue of diabetes and cavernous nerve injury-induced erectile dysfunction rat model

PURPOSE

To investigate the effects of cavernous nerve injury (CNI) on gene expression profiles in the cavernosal tissue of a CNI-induced erectile dysfunction (ED) model and to provide a basis for future investigations to discover potential target genes for ED treatment.

MATERIALS AND METHODS

Young adult rats were divided randomly into 2 groups: sham operation and bilateral CN resection. At 12 weeks after CNI we measured erectile responses and performed microarray experiments and gene set enrichment analysis to reveal gene signatures that were enriched in the CNI-induced ED model. Alterations in gene signatures were compared with those in the diabetes-induced ED model. The diabetic-induced ED data is taken from GSE2457.

RESULTS

The mean ratio of intracavernosal pressure/blood pressure for the CNI group (0.54±0.4 cmH2O) was significantly lower than that in the sham operation group (0.73±0.8 cmH2O, p<0.05). Supervised and unsupervised clustering analysis showed that the diabetes- and CNI-induced ED cavernous tissues had different gene expression profiles from normal cavernous tissues. We identified 46 genes that were upregulated and 77 genes that were downregulated in both the CNI- and diabetes-induced ED models.

CONCLUSIONS

Our genome-wide and computational studies provide the groundwork for understanding complex mechanisms and molecular signature changes in ED.

Animal models of erectile dysfunction

Erectile dysfunction (ED) is a prevalent male sexual dysfunction with profound adverse effects on the physical and the psychosocial health of men and, subsequently, on their partners. The expanded use of various types of rodent models has produced some advances in the study of ED, and neurophysiological studies using various animal models have provided important insights into human sexual dysfunction. At present, animal models play a key role in exploring and screening novel drugs designed to treat ED.

Alterations in lung gene expression in streptozotocin-induced diabetic rats

BACKGROUND

Diabetes profoundly affects gene expression in organs such as heart, skeletal muscle, kidney and liver, with areas of perturbation including carbohydrate and lipid metabolism, oxidative stress, and protein ubiquitination. Type 1 diabetes impairs lung function, but whether gene expression alterations in the lung parallel those of other tissue types is largely unexplored.

METHODS

Lung from a rat model of diabetes mellitus induced by streptozotocin was subjected to gene expression microarray analysis.

RESULTS

Glucose levels were 67 and 260 mg/dl (p < 0.001) in control and diabetic rats, respectively. There were 46 genes with at least ± 1.5-fold significantly altered expression (19 increases, 27 decreases). Gene ontology groups with significant over-representation among genes with altered expression included apoptosis, response to stress (p = 0.03), regulation of protein kinase activity (p = 0.04), ion transporter activity (p = 0.01) and collagen (p = 0.01). All genes assigned to the apoptosis and response to stress groups had increased expression whereas all genes assigned to the collagen group had decreased expression. In contrast, the protein kinase activity and ion transporter activity groups had genes with both increased and decreased expression.

CONCLUSIONS

Gene expression in the lung is affected by type 1 diabetes in several specific areas, including apoptosis. However, the lung is resistant to changes in gene expression related to lipid and carbohydrate metabolism and oxidative stress that occur in other tissue types such as heart, skeletal muscle and kidney.

Oral L-citrulline supplementation improves erectile function in rats with acute arteriogenic erectile dysfunction

INTRODUCTION

Oral L-citrulline supplementation increases serum L-arginine levels more efficiently than L-arginine itself and increases nitric oxide (NO) production.

AIM

To investigate whether oral L-citrulline supplementation improves erectile function in rats with acute arteriogenic erectile dysfunction (ED).

METHODS

We divided 8-week-old male Wistar-ST rats into 3 groups: sham-operated rats (control group), arteriogenic ED rats who underwent ligation of both internal iliac arteries (ligation group), and arteriogenic ED rats receiving oral 2% L-citrulline water supplementation (citrulline group). Citrulline water was given to arteriogenic ED rats for 3 weeks from 1 week after surgery. Erectile function was evaluated by maximum intracavernous pressure/mean arterial pressure (ICP/MAP) ratios via cavernous nerve stimulation at 4 weeks after surgery. Then, the penises were resected, stained with Masson's trichrome, and observed microscopically. Serum nitrogen oxides (NOx) levels were measured by high-performance liquid chromatography. Bonferroni's multiple t-test was used for statistical analysis.

MAIN OUTCOME MEASURES

The main outcome measures were changes in ICP/MAP, smooth muscle (SM)/collagen ratios, and NOx levels following L-citrulline supplementation.

RESULTS

The ICP/MAP ratio in the ligation group was significantly lower than that in the control group (P<0.05), denoting ED. The ICP/MAP ratio of the citrulline group was significantly higher than that of the ligation group (P<0.05), indicating ED amelioration. Levels of NOx in the ligation group were significantly lower than in the control group (P<0.05), while those in the citrulline group were significantly higher than in the ligation group (P<0.05). SM/collagen ratios in the ligation group were significantly lower than in the control group (P<0.05), while ratios in the citrulline group were significantly higher than those in the ligation group (P<0.05).

CONCLUSIONS

Oral L-citrulline supplementation improved ICP/MAP and SM/collagen ratios and increased NOx. Therefore, oral L-citrulline supplementation might be a useful novel therapy for acute arteriogenic ED.

Does dietary copper supplementation enhance or diminish PCB126 toxicity in the rodent liver?

Copper is essential for the function of the mitochondrial electron transport chain and several antioxidant proteins. However, in its free form copper can participate in Fenton-like reactions that produce reactive hydroxyl radicals. Aryl-hydrocarbon receptor (AhR) agonists, including the most potent polychlorinated biphenyl (PCB) congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), increase copper levels in rodent livers. This is accompanied by biochemical and toxic changes. To assess the involvement of copper in PCB toxicity, male Sprague-Dawley rats were fed an AIN-93G diet with differing dietary copper levels: low (2 ppm), adequate (6 ppm), and high (10 ppm). After three weeks, rats from each group were given a single ip injection of corn oil (control), 1, or 5 μmol/kg body weight PCB126. Two weeks following injections, biochemical and morphological markers of hepatic toxicity, trace metal status, and hepatic gene expression of metalloproteins were evaluated. Increasing dietary copper was associated with elevated tissue levels of copper and ceruloplasmin. In the livers of PCB126-treated rats, the hallmark signs of AhR activation were present, including increased cytochrome P450 and lipid levels and decreased glutathione. In addition, a doubling of hepatic copper levels was seen, and overall metal homeostasis was disturbed, resulting in decreased hepatic selenium, manganese, zinc, and iron. Expression of key metalloproteins was either decreased (cytochrome c oxidase), unchanged (ceruloplasmin and CuZnSOD), or increased (tyrosinase and metallothioneins 1 and 2) with exposure to PCB126. Increases in metallothionein may contribute/reflect the increased copper seen. Alterations in dietary copper did not amplify or abrogate the hepatic toxicity of PCB126. PCB126 toxicity, i.e., oxidative stress and steatosis, is clearly associated with disturbed metal homeostasis. Understanding the mechanisms of this disturbance may provide tools to prevent liver toxicity by other AhR agonists.

Pilot genome-wide association search identifies potential loci for risk of erectile dysfunction in type 1 diabetes using the DCCT/EDIC study cohort

PURPOSE

We identified genetic predictors of diabetes associated erectile dysfunction using genome-wide and candidate gene approaches in a cohort of men with type 1 diabetes.

MATERIALS AND METHODS

We examined 528 white men with type 1 diabetes, including 125 with erectile dysfunction, from DCCT (Diabetes Control and Complications Trial) and its observational followup, the EDIC (Epidemiology of Diabetes Interventions and Complications) study. Erectile dysfunction was identified from a single International Index of Erectile Function item. A Human1M BeadChip (Illumina®) was used for genotyping. A total of 867,125 single nucleotide polymorphisms were subjected to analysis. Whole genome and candidate gene approaches were used to test the hypothesis that genetic polymorphisms may predispose men with type 1 diabetes to erectile dysfunction. Univariate and multivariate models were used, controlling for age, HbA1c, diabetes duration and prior randomization to intensive or conventional insulin therapy during DCCT. A stratified false discovery rate was used to perform the candidate gene approach.

RESULTS

Two single nucleotide polymorphisms located on chromosome 3 in 1 genomic loci were associated with erectile dysfunction with p <1 × 10(-6), including rs9810233 with p = 7 × 10(-7) and rs1920201 with p = 9 ×10(-7). The nearest gene to these 2 single nucleotide polymorphisms is ALCAM. Genetic association results at these loci were similar on univariate and multivariate analysis. No candidate genes met the criteria for statistical significance.

CONCLUSIONS

Two single nucleotide polymorphisms, rs9810233 and rs1920101, which are 25 kb apart, are associated with erectile dysfunction, although they do not meet the standard genome-wide association study significance criterion of p <5 × 10(-8). Other studies with larger sample sizes are required to determine whether ALCAM represents a novel gene in the pathogenesis of diabetes associated erectile dysfunction.

Differentially expressed angiogenic genes in diabetic erectile tissue - results from a microarray screening

Diabetes-induced metabolic derangements promote endothelial malfunction, contributing to erectile dysfunction (ED). However, it remains unclear which angiogenic molecular mechanisms are deregulated in diabetic corpus cavernosum (CC). We investigated early and late alterations in cavernosal angiogenic gene expression associated to diabetes. Angiogenic changes were assessed in penile tissue of streptozotocin-induced Wistar rats, in an early (2-week) and established stage (8-week) of diabetes. Differentially expressed genes were identified by microarrays and expression data validated by quantitative real-time PCR (qrt-PCR). At protein level, quantitative immunohistochemistry confirmed the arrays data and dual immunofluorescence for selected alterations and α-smooth muscle actin (α-SMA) identified the cellular location of target proteins. The selected differentially expressed genes were also evaluated in human non-diabetic and diabetic CC by quantitative immunolabeling. At 2-week diabetes there was no differential gene expression between non-diabetic and diabetic CC. At 8-week, 10 genes were found down-regulated in diabetics. The results were validated by qrt-PCR for the insulin-like growth factor-1 (Igf1) and the natriuretic peptide receptor-1 (Npr1) genes. Dual immunofluorescence for IGF-1/ α-SMA showed predominant localization of IGF-1 in SM. NPR-1 expression was diffuse and mostly present in trabecular fibroblasts and SM. Quantitative immunostaining confirmed the decreased expression of both proteins in diabetic tissues. Concordantly, we detected a significant reduction in IGF-1 and NPR-1 protein expressions in human diabetic samples. Microarray analysis identified 10 angiogenic-related molecules deregulated in CC of established diabetes. Among them, IGF-1 and NPR-1 were significantly down-regulated and might result in preventive/therapeutic targets for ED management.

Markers of erectile dysfunction

With the development and marketing of oral pharmacotherapy that is both noninvasive and successful in treating erectile dysfunction (ED), the quest to identify markers of organic ED lost ground. Indeed, the multi-factorial nature of ED may have led many researchers to conclude that searching for a universal marker of ED was futile. However, the realization that ED is strongly correlated with the overall health of men, and may act as a predictor for the development of cardiovascular disease (CVD) and diabetes, has stimulated interest in identifying genes that can distinguish organic ED. In addition, the potential ability to suggest to the patient that ED is reversible (i.e., psychogenic) with a simple test would be of significance to both the physician and patient, as well as for reimbursement issues for therapy by insurance companies. Such a marker may also act as a non-subjective measure of the degree of ED and the efficacy of treatment. This review discusses the importance of identifying such markers and recent work identifying potential markers in human patients.

Oxygenomics in environmental stress

Environmental stressors such as chemicals and physical agents induce various oxidative stresses and affect human health. To elucidate their underlying mechanisms, etiology and risk, analyses of gene expression signatures in environmental stress-induced human diseases, including neuronal disorders, cancer and diabetes, are crucially important. Recent studies have clarified oxidative stress-induced signaling pathways in human and experimental animals. These pathways are classifiable into several categories: reactive oxygen species (ROS) metabolism and antioxidant defenses, p53 pathway signaling, nitric oxide (NO) signaling pathway, hypoxia signaling, transforming growth factor (TGF)-beta bone morphogenetic protein (BMP) signaling, tumor necrosis factor (TNF) ligand-receptor signaling, and mitochondrial function. This review describes the gene expression signatures through which environmental stressors induce oxidative stress and regulate signal transduction pathways in rodent and human tissues.

Oxidative stress status accompanying diabetic bladder cystopathy results in the activation of protein degradation pathways

OBJECTIVE

• To investigate the role that oxidative stress plays in the development of diabetic cystopathy.

MATERIALS AND METHODS

• Comparative gene expression in the bladder of non-diabetic and streptozotocin (STZ)-induced 2-month- old diabetic rats was carried out using microarray analysis. • Evidence of oxidative stress was investigated in the bladder by analyzing glutathione S-transferase activity, lipid peroxidation, and carbonylation and nitrosylation of proteins. • The activity of protein degradation pathways was assessed using Western blot analysis.

RESULTS

• Analysis of global gene expression showed that detrusor smooth muscle tissue of STZ-induced diabetes undergoes significant enrichment in targets involved in the production or regulation of reactive oxygen species (P = 1.27 × 10(-10)). The microarray analysis was confirmed by showing that markers of oxidative stress were all significantly increased in the diabetic bladder. • It was hypothesized that the sequelae to oxidative stress would be increased protein damage and apoptosis. • This was confirmed by showing that two key proteins involved in protein degradation (Nedd4 and LC3B) were greatly up-regulated in diabetic bladders compared to controls by 12.2 ± 0.76 and 4.4 ± 1.0-fold, respectively, and the apoptosis inducing protein, BAX, was up-regulated by 6.76 ± 0.76-fold.

CONCLUSION

• Overall, the findings obtained in the present study add to the growing body of evidence showing that diabetic cystopathy is associated with oxidative damage of smooth muscle cells, and results in protein damage and activation of apoptotic pathways that may contribute to a deterioration in bladder function.

Sustained hypercapnia induces cerebral microvascular degeneration in the immature brain through induction of nitrative stress

Hypercapnia is regularly observed in chronic lung disease, such as bronchopulmonary dysplasia in preterm infants. Hypercapnia results in increased nitric oxide synthase activity and in vitro formation of nitrates. Neural vasculature of the immature subject is particularly sensitive to nitrative stress. We investigated whether exposure to clinically relevant sustained high CO2 causes microvascular degeneration in the newborn brain by inducing nitrative stress, and whether this microvascular degeneration has an impact on brain growth. Newborn rat pups were exposed to 10% CO2 as inspired gas (PaCO2 = 60–70 mmHg) starting within 24 h of birth until postnatal day 7 (P7). Brains were notably collected at different time points to measure vascular density, determine brain cortical nitrite/nitrate, and trans-arachidonic acids (TAAs; products of nitration) levels as effectors of vessel damage. Chronic exposure of rat pups to high CO2 (PaCO2 ≈ 65 mmHg) induced a 20% loss in cerebrovascular density at P3 and a 15% decrease in brain mass at P7; at P30, brain mass remained lower in CO2-exposed animals. Within 24 h of exposure to CO2, brain eNOS expression and production of nitrite/nitrate doubled, lipid nitration products (TAAs) increased, and protein nitration (3-nitrotyrosine immunoreactivity) was also coincidently augmented on brain microvessels (lectin positive). Intracerebroventricular injection of TAAs (10 μM) replicated cerebrovascular degeneration. Treatment of rat pups with NOS inhibitor (l-Nω-nitroarginine methyl ester) or a peroxynitrite decomposition catalyst (FeTPPS) prevented hypercapnia-induced microvascular degeneration and preserved brain mass. Cytotoxic effects of high CO2 were reproduced in vitro /ex vivo on cultured endothelial cells and sprouting microvessels. In summary, hypercapnia at values frequently observed in preterm infants with chronic lung disease results in increased nitrative stress, which leads to cerebral cortical microvascular degeneration and curtails brain growth.

Molecular targets for diabetes mellitus-associated erectile dysfunction

Protein expression profiles in rat corporal smooth muscle tissue were compared between animal models of streptozotocin-induced diabetes mellitus (STZ-DM) and age-matched controls (AMCs) at 1 week and 2 months after induction of hyperglycemia with STZ treatment. At each time point, protein samples from four STZ-DM and four AMC rat corpora tissues were prepared independently and analyzed together across multiple quantitative two-dimensional gels using a pooled internal standard sample to quantify expression changes with statistical confidence. A total of 170 spots were differential expressed among the four experimental groups. A subsequent mass spectrometry analysis of the 170 spots identified a total of 57 unique proteins. Network analysis of these proteins using MetaCore suggested altered activity of transcriptional factors that are of too low abundance to be detected by the two-dimensional gel method. The proteins that were down-regulated with diabetes include isoforms of collagen that are precursors to fibril-forming collagen type 1; Hsp47, which assists and mediates the proper folding of procollagen; and several proteins whose abundance is controlled by sex hormones (e.g. CRP1 and A2U). On the other hand, proteins seen or predicted to be up-regulated include proteins involved in cell apoptosis (e.g. p53, 14-3-3-gamma, Serpinf1, Cct4, Cct5, and Sepina3n), proteins that neutralize the biological activity of nerve growth factor (e.g. anti-NGF 30), and proteins involved in lipid metabolism (e.g. apoA-I and apoA-IV). Subsequent Western blot validation analysis of p53, 14-3-3-gamma, and Hsp47 confirmed increased p53 and 14-3-3-gamma and decreased Hsp47 levels in separate samples. According to the results from the Western blot analysis, Hsp47 protein showed a approximately 3-fold decrease at 1 week and was virtually undetectable at 2 months in diabetic versus control. Taken together, our results identify novel candidate proteins playing a role in erectile dysfunction in diabetes resulting from STZ treatment.

Gene expression profiling in the type 1 diabetes rat diaphragm

BACKGROUND

Respiratory muscle contractile performance is impaired by diabetes, mechanisms of which included altered carbohydrate and lipid metabolism, oxidative stress and changes in membrane electrophysiology. The present study examined to what extent these cellular perturbations involve changes in gene expression.

METHODOLOGY/PRINCIPAL FINDINGS

Diaphragm muscle from streptozotocin-diabetic rats was analyzed with Affymetrix gene expression arrays. Diaphragm from diabetic rats had 105 genes with at least +/-2-fold significantly changed expression (55 increased, 50 decreased), and these were assigned to gene ontology groups based on over-representation analysis using DAVID software. There was increased expression of genes involved in palmitoyl-CoA hydrolase activity (a component of lipid metabolism) (P = 0.037, n = 2 genes, fold change 4.2 to 27.5) and reduced expression of genes related to carbohydrate metabolism (P = 0.000061, n = 8 genes, fold change -2.0 to -8.5). Other gene ontology groups among upregulated genes were protein ubiquitination (P = 0.0053, n = 4, fold change 2.2 to 3.4), oxidoreductase activity (P = 0.024, n = 8, fold change 2.1 to 6.0), and morphogenesis (P = 0.012, n = 10, fold change 2.1 to 4.3). Other downregulated gene groups were extracellular region (including extracellular matrix and collagen) (P = 0.00032, n = 13, fold change -2.2 to -3.7) and organogenesis (P = 0.032, n = 7, fold change -2.1 to -3.7). Real-time PCR confirmed the directionality of changes in gene expression for 30 of 31 genes tested.

CONCLUSIONS/SIGNIFICANCE

These data indicate that in diaphragm muscle type 1 diabetes increases expression of genes involved in lipid energetics, oxidative stress and protein ubiquitination, decreases expression of genes involved in carbohydrate metabolism, and has little effect on expression of ion channel genes. Reciprocal changes in expression of genes involved in carbohydrate and lipid metabolism may change the availability of energetic substrates and thereby directly modulate fatigue resistance, an important issue for a muscle like the diaphragm which needs to contract without rest for the entire lifetime of the organism.

Transcriptional profiling of human cavernosal endothelial cells reveals distinctive cell adhesion phenotype and role for claudin 11 in vascular barrier function

To determine specific molecular features of endothelial cells (ECs) relevant to the physiological process of penile erection we compared gene expression of human EC derived from corpus cavernosum of men with and without erectile dysfunction (HCCEC) to coronary artery (HCAEC) and umbilical vein (HUVEC) using Affymetrix GeneChip microarrays and GeneSifter software. Genes differentially expressed across samples were partitioned around medoids to identify genes with highest expression in HCCEC. A total of 190 genes/transcripts were highly expressed only in HCCEC. Gene Ontology classification indicated cavernosal enrichment in genes related to cell adhesion, extracellular matrix, pattern specification and organogenesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed high expression of genes relating to ECM-receptor interaction, focal adhesions, and cytokine-cytokine receptor interaction. Real-time PCR confirmed expression differences in cadherins 2 and 11, claudin 11 (CLDN11), desmoplakin, and versican. CLDN11, a component of tight junctions not previously described in ECs, was highly expressed only in HCCEC and its knockdown by siRNA significantly reduced transendothelial electrical resistance in HCCEC. Overall, cavernosal ECs exhibited a transcriptional profile encoding matrix and adhesion proteins that regulate structural and functional characteristics of blood vessels. Contribution of the tight junction protein CLDN11 to barrier function in endothelial cells is novel and may reflect hemodynamic requirements of the corpus cavernosum.

Early inhibition of EGFR signaling prevents diabetes-induced up-regulation of multiple gene pathways in the mesenteric vasculature

Diabetes mellitus is associated with vascular complications including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive hormones. However, the signaling mechanisms leading to vascular dysfunction in diabetes are not fully understood. This microarray-based study was designed to identify differential gene expression between the normal and diabetic mesenteric vasculature and to investigate the effect of inhibiting epidermal growth factor receptor (EGFR) signaling on global gene expression in the mesenteric bed of streptozotocin (STZ)-induced diabetic rats. Transcriptome analysis was performed in triplicate using oligonucleotide microarrays housing 10,000 rat genes on the mesenteric bed of normal, diabetic, and diabetic rats treated with AG1478, a selective inhibitor of EGFR. Four weeks of diabetes led to a profound alteration in gene expression within the mesenteric bed with 1167 of the 3074 annotated genes being up-regulated and 141 genes down-regulated by at least 2-fold. The up-regulated gene ontologies included receptor tyrosine kinases, G-protein coupled receptors and ion channel activity. In particular, significant overexpressions of colipase, phospholipase A2, carboxypeptidases, and receptor tyrosine kinases such as EGFR, erbB2 and fibroblast growth factor receptor were observed in diabetes mesenteric vasculature. A 4-week intraperitoneal treatment of diabetic animals with AG1478 (1.2 mg/kg/alt diem) beginning on the same day as STZ injection prevented up-regulation of the majority (approximately 95%) of the genes associated with STZ diabetes including those apparently "unrelated" to the known EGFR pathway without correction of hyperglycemia. These results suggest that activation of EGFR signaling is a key initiating step that leads to induction of multiple signaling pathways in the development of diabetes-induced vascular dysfunction. Thus, therapeutic targeting of EGFR may represent a novel strategy for the prevention and/or treatment of vascular dysfunction in diabetes.

Superoxide dismutase analog (Tempol: 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine 1-oxyl) treatment restores erectile function in diabetes-induced impotence

We hypothesized that administration of the superoxide dismutase (SOD) mimetic Tempol (4-hydroxy-2, 2, 6, 6-tetramethylpiperidine 1-oxyl) may reverse diabetes induced ED(erectile dysfunction). To test this hypothesis, ROS related genes (SOD1, SOD2, GPx1, CAT, NOS2, NOS3), erectile functional studies, and immunohistochemical analysis were performed in diabetic rats treated with or without Tempol. Thirty Sprague-Dawley (3–4 months old) rats were divided into 3 groups (n=10 each), 20 with diabetes (diabetic control and Tempol treatment) and 10 healthy controls. Twelve weeks after induction of diabetes by streptozotocin and Tempol treatment, all groups underwent in vivo cavernous nerve stimulation. Rat crura were harvested and expression of antioxidative defense enzymes examined by semi-quantitative RT-PCR. To confirm the RT-PCR results, we performed immunohistochemistry (IHC) for catalase (CAT) and iNOS (NOS2). Nitration of tyrosine groups in proteins was also examined by IHC. Mean intracavernous pressure in the diabetic group was significantly lower than in healthy controls (p<0.001) and was reversed by Tempol treatment (p<0.0108). NOS2 protein expression was significantly increased in diabetic animals compared to healthy controls and Tempol restored NOS2 protein level. Nitrotyrosine was also higher in diabetic animals and though Tempol treatment decreased its formation, it remained higher than that found in healthy controls. This study suggests that Tempol treatment increased erectile function through modulating oxidative stress related genes in diabetic rats. This is the first report about the relationship between diabetes induced erectile dysfunction and oxidative stress, and anti-oxidative therapy using the superoxide dismutase mimetic, Tempol to restore erectile function.

Erection induced by Tx2-6 toxin of Phoneutria nigriventer spider: expression profile of genes in the nitric oxide pathway of penile tissue of mice

The peptides Tx2-5 and Tx2-6, isolated from the whole venom of "armed-spider"Phoneutria nigriventer venom, are directly linked with the induction of persistent and painful erection in the penis of mammals. The erection induced by Tx2-6 has been associated with the activation of nitric oxide synthases. There is a scarcity of studies focusing on the outcome of Tx2-6 at the molecular level, by this reason we evaluated the gene profile activity of this toxin at the nitric oxide (NO) pathway. After microarray analyses on cavernous tissue of mice inoculated with Tx2-6 we found that only 10.4% (10/96) of these genes were differentially expressed, showing a limited effect of the toxin on the NO pathway. We found the genes sparc, ednrb, junb, cdkn1a, bcl2, ccl5, abcc1 over-expressed and the genes sod1, s100a10 and fth1 under-expressed after inoculation of Tx2-6. The differential expressions of sparc and ednrb genes were further confirmed using real-time PCR. Interestingly, ednrb activates the L-arginine/NO/cGMP pathway that is involved in the relaxation of the cavernous body. Therefore the priapism induced by Tx2-6 is a consequence of a highly specific interference of this neurotoxin with the NO pathway.

Vcsa1 acts as a marker of erectile function recovery after gene therapeutic and pharmacological interventions

PURPOSE

We identified molecular markers of erectile function, particularly those responding to erectile dysfunction treatment.

MATERIALS AND METHODS

Sprague-Dawley retired breeder rats were intracorporeally injected with pVAX-hSlo, pSMAA-hSlo or the control plasmid pVAX. One week later the intracorporeal pressure-to-blood pressure ratio and gene expression were determined by microarray analysis and quantitative reverse transcriptase-polymerase chain reaction. Rat corporeal cells were transfected in vitro with pVAX-hSlo, pSMAA-hSlo or pVAX and the change in gene expression was determined. We also determined whether Vcsa1 expression was changed after pharmacotherapy using tadalafil.

RESULTS

Animals treated with vectors expressing hSlo had significantly improved erectile function compared to that in controls, accompanied by changed expression of a subset of genes. Vcsa1 was one of the genes that was most changed in expression (the third of approximately 31,000 with greater than 10-fold up-regulation). Changes in gene expression were different than those observed in corporeal cells transfected in vitro, distinguishing gene expression changes that were a direct effect of hSlo over expression. When tadalafil was administered in retired breeder rats, the Vcsa1 transcript increased 4-fold in corporeal tissue compared to that in untreated controls.

CONCLUSIONS

Our study identifies a set of genes that are changed in response to improved erectile function, rather than as a direct effect of treatment. We noted Vcsa1 may act as marker of the restoration of erectile function after gene transfer and pharmacotherapy.

The use of gene transfer technology to study the pathophysiology of erectile dysfunction

INTRODUCTION

The past 25 years of basic science research on erectile physiology has been devoted to investigating the pathogenesis of erectile dysfunction. Research has led to a better understanding of the biochemical factors and intracellular mechanisms responsible for corporal smooth muscle contraction and relaxation, as well as the influence of endothelial-derived relaxing factors.

AIM

In this essay, we propose the use of gene transfer technology to study mechanisms of disease involved in penile vascular dysfunction.

METHODS

The development of methods to deliver therapeutic genes to the penis has kindled a keen interest in treating ED with gene- and cell-based therapies.

RESULTS

Gene therapy has delineated putative mechanisms of disease in animal models of erectile dysfunction.

CONCLUSION

Investigation of animal models using gene therapy may ultimately lead to mechanism-based therapies for the treatment of erectile dysfunction.

Regulation of lysyl oxidase in vascular cells: lysyl oxidase as a new player in cardiovascular diseases

Lysyl oxidase (LOX) plays a crucial role in the maintenance of extracellular matrix stability and could participate in vascular remodelling associated with cardiovascular diseases. Evidence from in vitro and in vivo studies shows that LOX downregulation is associated with the endothelial dysfunction characteristic of earlier stages of the atherosclerotic process. Conversely, upregulation of this enzyme in vascular cells could induce neointimal thickening in atherosclerosis and restenosis. In fact, LOX is chemotactic for vascular smooth muscle cells and monocytes, is modulated by proliferative stimulus in these cells, and could control other cellular processes such as gene expression and cell transformation. Furthermore, it is conceivable that LOX downregulation could underlie plaque instability and contribute to the destructive remodelling that takes place during aneurysm development. Overall, LOX could play a key role in vascular homeostasis and, hence, it emerges as a new player in cardiovascular diseases. This review addresses the experimental evidence related to the role of LOX in vascular disorders and the potential benefits of controlling its expression and function.