Ferroptosis is involved in corpus cavernosum smooth muscle cells impairment in diabetes mellitus-induced erectile dysfunction

Adipose stem cells ameliorate erectile dysfunction in diabetes mellitus rats by attenuating ferroptosis through NRP1 with SLC7A11 interaction

BACKGROUND

Adipose stem cells (ADSCs) have garneVred increasing attention for their potential to treat diabetes mellitus erectile dysfunction (DMED), but the underlying molecular mechanisms remain unclear. The aim of this study was to identify and investigate the key cytokines and mechanisms by which ADSCs improve erectile function in DMED rats.

METHODS

We performed in vivo and in vitro assays, including rat erectile function assessment, cell co-culture, cytokine microarray screening and co-immunoprecipitation to investigate the role of ADSCs in improving erectile function in DMED rats.

RESULTS

Our analyses confirmed the occurrence of ferroptosis in the corpus cavernosum of DMED rats, while ADSCs treatment significantly restored erectile function and improved relevant indicators of ferroptosis. In vitro assays further indicated that corpus cavernosum smooth muscle cells (CCSMCs) co-cultured with ADSCs exhibited enhanced resistance to ferroptosis, with notably lower levels of cytoplasmic and lipid reactive oxygen species compared to the ferroptosis inducer Erastin-treated group. Mechanistic studies revealed that Neuropilin 1 (NRP1) may be a key molecule in ADSCs to improve erectile function in DMED rats. Furthermore, NRP1 in CCSMCs can interact with solute carrier family 7 member 11 (SLC7A11) to enhance the function of the glutamate-cysteine countertransport (Xc-) system and ferroptosis resistance in CCSMCs.

CONCLUSION

In conclusion, our findings indicate that NRP1 is a key molecule for ADSCs treatment to alleviate ferroptosis and improve erectile function in DMED rats, providing a promising target for DMED treatment and prognosis.

Revisiting experimental models of erectile dysfunction and their value in drug discovery and development

INTRODUCTION

Erectile dysfunction (ED) is a common condition that often signals underlying endothelial dysfunction, although the underlying causative factor(s) are likely complex and multifactorial. Various animal models have been developed to provide a research platform to study ED and served as an important basis for the discovery and subsequent development of novel therapeutic drugs for ED.

AREAS COVERED

The review article provides an overview of various animal models in ED research with an emphasis on important drug target discovery relating to each specific experimental model. The authors highlight translation from basic science research to major preclinical and clinical studies in this evolving field of ED research.

EXPERT OPINION

Animal models simulate the pathological features of various types of ED and clarify their molecular mechanisms. These mechanisms aid in discovering drug targets, while established ED models also provide a basis for validating drug efficacy, safety, and specific action mechanisms. The development of techniques in detection methods, cellular experimental, and omics has a profound impact on disease prediction, model evaluation, and optimization of therapeutic modalities. On this basis, many drug therapies targeting these ED-related mechanisms, especially in the nitric oxide/cyclic guanosine monophosphate pathways have been applied in preclinical studies. However, focusing on drug development for those types of ED where phosphodiesterase 5 inhibitor therapy is limited may be more valuable.

The role of programmed cell death in diabetes mellitus-induced erectile dysfunction: from mechanisms to targeted therapy

Diabetes mellitus (DM) is a chronic metabolic disease that often leads to vascular endothelial injury and peripheral neuropathy. Erectile dysfunction (ED), a common condition in andrology, is frequently associated with DM. The incidence of diabetes mellitus-induced ED (DMED) is second only to the cardiovascular complications of diabetes. Compared to other types of ED, DMED presents with more severe symptoms, rapid progression, and notable resistance to phosphodiesterase type 5 inhibitors (PDE5is). Various forms of programmed cell death (PCD)-including apoptosis, autophagy, pyroptosis, and ferroptosis-play pivotal roles in the pathogenesis of DMED. An exacerbation of DMED is linked to critical irritants like advanced glycation end-products (AGEs) and reactive oxygen species (ROS) in the corpus cavernosum tissue. These irritants can spark anomalous activations of diverse PCDs, which damage primary corpus cavernosum cells like cavernous nerve cells, endothelial cells, and myocytes, leading to ED. Hence, we reviewed current knowledge on the mechanisms and therapeutic potential of targeting PCDs in DMED, aiming to advance strategies for enhancing erectile function.

Icariin inhibits hyperglycemia-induced cell death in penile cavernous tissue and improves erectile function in type 1 diabetic rats

Background

Hyperglycemia can cause endothelial cell (EC) and smooth muscle cell (SMC) death in the penile cavernous tissue of rats and lead to erectile dysfunction (ED).

Objectives

To investigate the proportions of apoptotic, pyroptotic, and ferroptotic cells among ECs and SMCs in the penile cavernous tissue of type 1 diabetic (T1DM) rats and the mechanism by which icariin (ICA) improves the erectile function of T1DM rats.

Methods

A total of 24 9-week-old Sprague-Dawley (SD) rats were randomly divided into 4 groups (n = 6): control group, control + ICA group, diabetic mellitus (DM) group, and DM + ICA group. T1DM rats were generated via the intraperitoneal injection of STZ (45 mg/kg). After 8 weeks, the rats in the control + ICA group and the DM + ICA group were administered ICA (10 mg/kg/d) by gavage for 4 weeks. ROS, MDA, SOD, GSH, SM/C, and NO levels, and GPX4, ACSL4, caspase-1, GSDMD, caspase-3, CD31, α-SMA, and p-eNOS/eNOS expression in penile cavernous tissue and the ICPmax/MAP of 21-week-old rats were detected.

Results

The percentage of pyroptotic SMCs in penile cavernosum was no statistically significant difference among these groups. Vs control group, the percentages of apoptotic (20.70% ± 1.60%), pyroptotic (21.02% ± 1.97%), and ferroptotic (9.01% ± 2.00%) ECs and the percentages of apoptotic (15.47% ± 1.36%) and ferroptotic (26.33% ± 3.11%) SMCs in the penile cavernous tissue of the DM group were significantly greater. Vs DM group, the percentages of apoptotic (9.13% ± 1.28%), pyroptotic (13.22 ± 1.26%), and ferroptotic (4.01% ± 0.86%) ECs and the percentages of apoptotic (11.60% ± 1.91%) and ferroptotic (12.71% ± 2.92%) SMCs of the DM + ICA group were significantly lower. Vs the DM group, the levels of caspase-1, GSDMD, ACSL4, and ROS were significantly lower in the penile cavernous tissue of the DM + ICA group. Meanwhile, the levels of GPX4 and maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP) were significantly higher.

Clinical Implications

The combined inhibition of apoptosis, pyroptosis, and ferroptosis in penile cavernous tissue by ICA provides a theoretical basis for the clinical development of multi-target drugs for the treatment of type 1 diabetes-induced ED.

Strengths and Limitations

Further experiments are required to clarify whether other types of cell death are involved in the loss of ECs and SMCs in the penile cavernous tissue of T1DM rats.

Conclusion

Inhibiting oxidative stress and thereby inhibiting apoptosis, pyroptosis, and ferroptosis in ECs and SMCs of penile cavernous tissue constitute one of the mechanisms through which ICA improves erectile function in T1DM rats.

The conserved molecular mechanism of erectile dysfunction in type 2 diabetes rats and mice by cross-species transcriptomic comparisons

Background

The poor clinical situation of type 2 diabetes-induced erectile dysfunction (T2DMED) creates an urgent need for new therapeutic targets.

Aim

To reveal the conserved molecular mechanism of T2DMED across species.

Methods

T2DMED rat and mouse models were constructed to extract mRNA from corpus cavernosum for high-throughput sequencing. The differentially expressed genes (DEGs) were analyzed and the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Protein-Protein Interaction Networks were performed by bioinformatics methods. Immunohistochemistry, immunofluorescence, hematoxylin- eosin and Masson staining were used for subsequent verification.

Outcomes

Cross-species transcriptomics of T2DMED rats and mice were analyzed and validated.

Results

Gene expression patterns in normal corpus cavernosum of mice and rats showed a strong correlation (r = 0.75, P < 2.2 × 10-16), with a total of 15 691 homologous genes identified. In both species, 553 homologous down-regulated DEGs were identified, mainly enriched in pathways related to smooth muscle and mitochondrial functions, as revealed by KEGG and GO analyses. Immunohistochemistry and immunofluorescence confirmed the decreased expression of α-smooth muscle actin and Uqcr10 in cavernosum tissues of T2DMED mice and rats. Additionally, 239 homologous up-regulated DEGs were identified, which were enriched in the Wnt signaling pathway and extracellular matrix composition. Subsequent experiments confirmed increased β-catenin expression and significant collagen accumulation, indicating fibrosis in T2DMED.

Clinical implications

To provide a new direction for improving the erectile ability of patients with T2DMED.

Strengths and limitations

The main strength is that cross-species transcriptomic sequencing has revealed the conserved molecular mechanisms of T2DMED. The main limitation is the lack of further validation in the T2DMED patients.

Conclusions

Cross-species transcriptomic comparisons may offer a novel strategy for uncovering the underlying mechanisms and identifying therapeutic targets for T2DMED.

Concentration of Selected Serum Trace Elements in Male Patients With Diabetic Erectile Dysfunction: A Case-Control Study

Identifying novel risk factors for erectile dysfunction (ED) is crucial for developing targeted intervention. This study aimed to investigate the potential impacts of serum trace elements (TEs) concentration on the risk of diabetic ED. A retrospective case-control study was conducted involving 51 patients with diabetic ED and 51 control subjects. Serum levels of copper (Cu), zinc (Zn), magnesium (Mg), iron (Fe), and calcium (Ca) were measured using inductively coupled plasma-mass spectrometry (ICP-MS). While most selected TEs showed no significant differences, Cu levels were notably higher in patients with diabetic ED. In addition, the Cu/Zn ratio (CZr) was significantly elevated in the diabetic ED group compared to controls (1.3 vs. 1.2 mg/L, p < .001), reflecting its potential relevance to oxidative stress. Receiver operating characteristic curve analysis revealed that CZr exhibited better diagnostic performance for ED than the single parameter. These findings suggest disruptions in Cu homeostasis and a high probability of elevated CZr in diabetic ED. Further studies are warranted to validate our findings and elucidate the underlying mechanisms.

Neural Precursor Cell-Expressed Developmentally Downregulated Protein 4 (NEDD4)-Mediated Ubiquitination of Glutathione Peroxidase 4 (GPX4): A Key Pathway in High-Glucose-Induced Ferroptosis in Corpus Cavernosum Smooth Muscle Cells

Pharmacological treatment of diabetes mellitus-induced erectile dysfunction (DMED) has become increasingly challenging due to the limited efficacy of phosphodiesterase type 5 inhibitors (PDE5i). As the global prevalence of DM continues, there is a critical need for novel therapeutic strategies to address DMED. In our previous studies, we found that Glutathione peroxidase 4 (GPX4), a ferroptosis inhibitor, can ameliorate DMED in diabetic rats. However, the specific role of GPX4 in corpus cavernosum smooth muscle cells (CCSMCs) and its regulatory mechanisms remain unclear. In this study, we established primary cultures of CCSMCs and systematically analyzed the role of GPX4 under high-glucose conditions. To further elucidate the upstream regulatory pathways of GPX4, we employed immunoprecipitation coupled with mass spectrometry (IP-MS) to identify potential interacting proteins. Additionally, co-immunoprecipitation (Co-IP) and cycloheximide (CHX) chase assays were conducted to explore the regulatory dynamics and post-translational stability of GPX4. Under high-glucose conditions, the expression of GPX4 in CCSMCs is significantly downregulated, leading to an increase in intracellular oxidative stress and heightened levels of ferroptosis, accompanied by dysfunction in smooth muscle cell relaxation. Furthermore, the CHX chase assay revealed that high glucose accelerates GPX4 protein degradation via the ubiquitin-proteasome pathway. Subsequent IP-MS identified NEDD4, an E3 ubiquitin ligase, as a potential interacting partner of GPX4. Further validation demonstrated that NEDD4 modulates the ubiquitination process of GPX4, thereby influencing its stability and expression. In conclusion, we identified NEDD4 as a key regulator of GPX4 stability through ubiquitin-mediated proteasomal degradation. These findings suggest potential therapeutic strategies targeting the NEDD4-GPX4 axis to alleviate DMED pathology.

Therapeutic potential of hesperidin in diabetes mellitus-induced erectile dysfunction through Nrf2-mediated ferroptosis and oxidative stress

BACKGROUND

Among erectile dysfunction (ED) caused by metabolic abnormalities, diabetes mellitus-induced ED (DMED) progresses rapidly, manifests with severe symptoms, and shows reduced responsiveness to conventional medications. Hyperglycemia in the corpus cavernosum has been linked to the induction of both ferroptosis and oxidative stress, which are mediated by nuclear factor E2 related factor 2 (Nrf2). Hesperidin (Hes), a flavonoid compound, has been revealed to activate Nrf2 in certain diabetic complications, yet the efficacy of Hes on DMED and the specific mechanism remain unclear.

OBJECTIVES

To elucidate the potential mechanism and efficacy of Hes in regulating Nrf2-mediated ferroptosis and oxidative stress in DMED.

MATERIALS AND METHODS

DMED rats were constructed through the intraperitoneal injection of streptozotocin (STZ), partially supplemented with Hes. In parallel, in vitro research utilized human umbilical vein endothelial cells (HUVECs), with glucose addition to simulating a high glucose (HG) environment, and induced with Hes or ML385 (an Nrf2 inhibitor). Penile tissues and HUVECs were harvested for subsequent analyses.

RESULTS

The results of this study indicate that Hes partially reversed the impaired erectile function. The expression of Nrf2, glutathione peroxidase 4 (GPX4), and heme oxygenase-1 (HO-1) in the corpus cavernosum elevated after supplementing with Hes, resulted in an inhibition in ferroptosis and oxidative stress. Moreover, the quantity and function of erectile effector cells were restored, and cavernous fibrosis was ameliorated. In HG-induced HUVECs, Hes ameliorated Nrf2-mediated ferroptosis and oxidative stress, effects which ML385 partially reversed.

CONCLUSIONS

Hes exerts a therapeutic effect on DMED rats and a regulatory mechanism on the Nrf2-HO-1/GPX4 axis, concurrently revitalizing endothelial and smooth muscle cells, and diminishing fibrosis. Our study provides robust preclinical evidence for employing Hes in treating DMED.

Therapeutic effects of natural compounds against diabetic complications via targeted modulation of ferroptosis

Diabetes mellitus, a chronic metabolic disorder, can result in serious tissue and organ damage due to long-term metabolic dysfunction, leading to various complications. Therefore, exploring the pathogenesis of diabetic complications and developing effective prevention and treatment drugs is crucial. The role of ferroptosis in diabetic complications has emerged as a significant area of research in recent years. Ferroptosis, a recently discovered form of regulated cell death closely linked to iron metabolism imbalance and lipid peroxidation, has garnered increasing attention in studies exploring the potential role of natural products in its regulation. This review provides an overview of the mechanisms underlying ferroptosis, outlines detection methods, and synthesizes information from natural product databases. It also summarizes current research on how natural products may regulate ferroptosis in diabetic complications. Studies have shown that these products can modulate the ferroptosis process by influencing iron ion balance and combating oxidative stress. This highlights the potential of natural products in treating diabetic complications by regulating ferroptosis, offering a new strategy for managing such complications.

Identification and validation of new fatty acid metabolism-related mechanisms and biomarkers for erectile dysfunction

Background

Erectile dysfunction (ED) is a common condition affecting middle-aged and elderly men.

Aim

The study sought to investigate differentially expressed fatty acid metabolism-related genes and the molecular mechanisms of ED.

Methods

The expression profiles of GSE2457 and GSE31247 were downloaded from the Gene Expression Omnibus database and merged. Differentially expressed genes (DEGs) between ED and normal samples were obtained using the R package limma. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses of DEGs were conducted using the R package clusterProfiler. Fatty acid metabolism-related DEGs (FAMDEGs) were further identified and analyzed. Machine learning algorithms, including Lasso (least absolute shrinkage and selection operator), support vector machine, and random forest algorithms, were utilized to identify hub FAMDEGs with the ability to predict ED occurrence. Coexpression analysis and gene set enrichment analysis of hub FAMDEGs were performed.

Outcome

Fatty acid metabolism-related functions (such as fatty acid metabolism and degradation) may play a vital role in ED.

Results

In total, 5 hub FAMDEGs (Aldh2, Eci2, Acat1, Acadl, and Hadha) were identified and found to be differentially expressed between ED and normal samples. Gene set enrichment analysis identified key pathways associated with these genes. The area under the curve values of the 5 hub FAMDEGs for predicting ED occurrence were all >0.8.

Clinical Translation

Our results suggest that these 5 key FAMDEGs may serve as biomarkers for the diagnosis and treatment of ED.

Strengths and Limitations

The strengths of our study include the use of multiple datasets and machine learning algorithms to identify key FAMDEGs. However, limitations include the lack of validation in animal models and human tissues, as well as research on the mechanisms of these FAMDEGs.

Conclusion

Five hub FAMDEGs were identified as potential biomarkers for ED progression. Our work may prove that fatty acid metabolism-related genes are worth further investigation in 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.

Low androgen levels induce ferroptosis of rat penile cavernous endothelial cells

Background

Endothelial dysfunction caused by low androgen levels in penile tissue can lead to erectile dysfunction. The exact mechanism of endothelial dysfunction has not been thoroughly studied.

Objective

The study sought to verify whether low androgen levels induce ferroptosis of endothelial cells in rat penile tissue.

Methods

Rat penile cavernous endothelial cells (CP-R133) were divided into a no-androgen group (Dihydrotestosterone (DHT): 0 nmol/L), very low-androgen group (DHT: 0.1 nmol/L), low-androgen group (DHT: 1 nmol/L), DHT = 10 nmol/L group, DHT (0 nmol/L) + ferrostatin-1 (Fer-1) group, DHT (0.1 nmol/L) + Fer-1 group, DHT (1 nmol/L) + Fer-1 group, DHT (10 nmol/L) + Fer-1 group. Cell viability, intracellular ferrous ion (Fe2+), malondialdehyde (MDA), GSH into oxidized glutathione (GSSG), reactive oxygen species (ROS), nitric oxide (NO), transferrin receptor 1 protein (TfR1), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4), endothelial nitric oxide synthase (eNOS), and phospho-eNOS (p-eNOS) were detected.

Outcomes

Low androgen levels could induce ferroptosis of rat penile cavernous endothelial cells in vivo by upregulating the expressions of TfR1 and ACSL4 and downregulating the expressions of SLC7A11 and GPX4.

Results

Cell viability, the levels of glutathione (GSH), NO, SLC7A11, GPX4, and p-eNOS/eNOS in the DHT = 0 nmol/L group were lower than those in the other groups (P < .05). The levels of Fe2+, ROS, MDA, GSSG, TfR1, and ACSL4 in the DHT = 0 nmol/L group were higher than those in the other groups (P < .05). Cell viability and the levels of GSH, NO, SLC7A11, GPX4, and p-eNOS/eNOS in the DHT = 1 nmol/L group were lower than those in the DHT (1 nmol/L) + Fer-1 group, DHT = 10 nmol/L group, and DHT (10 nmol/L) + Fer-1 group (P < .05). The levels of Fe2+, ROS, MDA, GSSG, TfR1, and ACSL4 in the DHT = 1 nmol/L group were higher than those in the DHT (1 nmol/L) + Fer-1 group, DHT = 10 nmol/L group, and DHT (10 nmol/L) + Fer-1 group (P < .05).

Clinical Implications

A ferroptosis inhibitor might be a novel drug for treating erectile dysfunction caused by low androgen level.

Strengths and Limitations

The results of this study need to be further confirmed in in vitro and in human studies. Meanwhile, further investigation is needed to clarify whether low androgen levels affect ferroptosis of rat penile cavernous smooth muscle and nerve cells.

Conclusion

Low androgen levels can induce ferroptosis of endothelial cells in rat penile tissue. Inhibition of ferroptosis can reverse endothelial dysfunction caused by low androgen levels.

Overexpression of PRDX2 in Adipose-Derived Mesenchymal Stem Cells Enhances the Therapeutic Effect in a Neurogenic Erectile Dysfunction Rat Model by Inhibiting Ferroptosis

Neurogenic erectile dysfunction (NED) is a common and serious complication after pelvic surgery. The clinical translation of adipose-derived mesenchymal stem cell (ADSC) therapies in NED remains a major challenge due to their low survival rate and limited therapeutic effect. Peroxiredoxin 2 (PRDX2) is a member of the peroxidase family that exerts its therapeutic effects by inhibiting oxidative stress (OS) and ferroptosis, and PRDX2 is expected to enhance the therapeutic effect of ADSCs in treating NED. The purpose of this study was to investigate whether PRDX2 could improve the survival of ADSCs and determine whether overexpression of PRDX2 in ADSCs (PRDX2-ADSCs) could enhance the therapeutic effect of NED. This study investigated the potential role of PRDX2-ADSCs through a NED model induced by bilateral cavernous nerve injury (BCNI) and three in vitro models established by H₂O₂-stimulated ADSCs, H₂O₂-stimulated corpus cavernosum smooth muscle cells (CCSMCs), and RSL3-stimulated CCSMCs. We found that PRDX2 could significantly improve the viability of ADSCs by suppressing apoptosis and OS in H₂O₂-stimulated ADSCs. We also found that BCNI triggered ferroptosis of the corpus cavernosum, which was manifested by increased reactive oxygen species (ROS), total iron content, and MDA as well as decreased SOD and GSH. Our results further demonstrated changes in the expression of key proteins (GPX4 and ACSL4) in the ferroptosis pathway, whereas PRDX2-ADSCs ameliorated BCNI-induced erectile dysfunction and ferroptosis of the corpus cavernosum in NED rats. Consistently, PRDX2-ADSCs attenuated OS in H₂O₂-stimulated CCSMCs and inhibited ferroptosis in RSL3-stimulated CCSMCs, as evidenced by the decrease in ROS, total iron content, and MDA and the increase in SOD and GSH together with changes in ferroptosis-related protein (GPX4 and ACSL4) expression. In conclusion, overexpression of PRDX2 in ADSCs enhanced the therapeutic effect in a rat model of neurogenic erectile dysfunction by inhibiting ferroptosis via regulation of the GPX4/ACSL4 axis.

A review of experimental techniques for erectile function researches and development of medical technology using animal erectile dysfunction models in sexual and reproductive medicine

Background

Erectile dysfunction (ED) is one of the causes of male infertility and is a disease that requires treatment. The first-line drugs for ED are phosphodiesterase 5 (PDE-5) inhibitors, and further treatment options are currently limited. Medical technologies, such as genetic control and regenerative medicine, are developing rapidly. Research on erectile function is progressing rapidly, coupled with technological innovations in other areas.

Methods

A PubMed search using the keywords "animal (rat, mouse, rabbit, dog, and monkey)" and "erectile" was conducted, and all relevant peer-reviewed English results were evaluated.

Main findings

The methods for evaluating erectile function include intracavernous pressure (ICP) measurements, isometric tension studies, and dynamic infusion cavernosometry. Papers also reported various disease model animals for the study of diabetes mellitus, cavernous nerve injury, and drug-induced ED.

Conclusion

Basic research on ED treatment has progressed rapidly over the past 20 years. In particular, research on the mechanism of ED has been accelerated by the publication of a study on the evaluation of erectile function using ICP measurements in rats. In addition, molecular biological experimental methods such as polymerase chain reaction (PCR) and western blotting have become relatively easy to perform due to technological progress, thus advancing research development.

Comparison of characteristics between Chinese diabetes mellitus-induced erectile dysfunction populations and non-diabetes mellitus-induced erectile dysfunction populations: A cross-sectional study

BACKGROUND

Erectile dysfunction (ED) is a common disease in adult men, and diabetes is an independent risk factor for ED. However, there are few reports on the distinction between diabetes mellitus-induced erectile dysfunction (DMED) and non-DMED features, as well as ED features of varying severity in the two groups.

METHODS

A total of 365 ED patients treated at two clinics in China from 2019 to 2022 were included. Questionnaires of the International Index of Erectile Function (IIEF-5), Erectile Hardness Score (EHS), Premature Ejaculation Diagnostic Tool (PEDT), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7) were administered to the patients. They were divided into three groups according to the IIEF-5 score: 5-7 for severe ED, 8-11 for moderate ED, and 12-21 for mild ED. In addition, the patient's age, weight, height, fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), total testosterone (TT) and other indicators were also collected. Statistical analysis was performed using SPSS 26, comparing all parameters between groups.

RESULTS

Age (P<0.001), height (P=0.009), body mass index (BMI) (P=0.002), PEDT (P<0.001), FBG (P<0.001), FSH (P<0.001), TG (P<0.001), TT (P<0.001) and triglyceride-glucose index (TyG) (P<0.001) were significantly different between diabetic ED and nondiabetic ED subjects. The trend test in the nondiabetic ED population found a negative correlation between the IIEF-5 score and PHQ-9 (P for trend=0.15). Multivariate ordinal logistic regression in the diabetic ED population showed that elevated LH OR=11.37 (95% CI: 0.966, 3.897) and elevated PRL OR=4.10 (95% CI: 0.410, 2.411) were associated with an increased risk of more severe ED.

CONCLUSIONS

The aetiology, demographic parameters, degree of premature ejaculation, and related biochemical tests were significantly different between the DMED and non-DMED populations.