Phenotypic transition of corpus cavernosum smooth muscle cells subjected to hypoxia

Using Network Pharmacology and in vivo Experiments to Uncover the Mechanisms of Radix Paeoniae Rubra and Radix Angelicae Sinensis Granules in Treating Diabetes Mellitus-Induced Erectile Dysfunction

Purpose

Diabetes mellitus-induced erectile dysfunction (DMED) lacks targeted therapies. This study investigates the mechanisms and targets of Radix Paeoniae Rubra and Radix Angelicae Sinensis Granules (RAG) in treating DMED using network pharmacology and animal models.

Methods

We identified RAG's active ingredients and potential targets from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. DMED targets were obtained from GeneCards, OMIM, and PharmGKB. Common targets were identified using R, and interaction networks were built. Cytoscape was used to construct a drug-ingredient-disease-target network, and OmicShare tools performed Gene Ontology and KEGG pathway analyses. Molecular Operating Environment software assessed compound-core gene interactions. Additionally, animal models were used for validation.

Results

Twenty compounds and 25 common targets linked to vasodilation, protein secretion, apoptosis, and hypoxia were selected. Key pathways included HIF-1, MAPK, cAMP, and Ras. Six core genes (INS, CAT, BDNF, CASP3, CRP, HMOX1) were targeted by RAG. Molecular docking showed stable interactions with oleic acid, catechin, and butylated hydroxytoluene. RAG increased NO, intracavernous pressure, and improved penile histology in rats, upregulating eNOS, iNOS, HMOX1, and downregulating HIF-1.

Conclusion

RAG may treat DMED via the HIF-1α/HMOX1 pathway, offering a potential novel therapy for DMED.

Mechanism of denervation muscle atrophy mediated by Ach/p38/MAPK pathway in rats with erectile dysfunction caused by nerve injury

BACKGROUND

Peripheral nerve injury can result in penile cavernosal denervation muscle atrophy, a primary factor in nerve injury erectile dysfunction (NED). While acetylcholine (Ach) is integral to erectile function, its role and mechanisms in NED need further exploration.

OBJECTIVE

To investigate the inhibition of CCMSCs Apoptosis and Protein Degradation Pathway by Ach in NED rat model.

METHODS

We investigated changes in Ach secretion and receptor expression in an NED rat model, followed by the evaluation of apoptosis and ubiquitin proteasome activation in hypoxic Cavernous smooth muscle cells (CCMSCs) and their co-cultures with Schwann cells (SWCs), under Ach influence. Further, key pathways in NED were identified via high-throughput sequencing, focusing on the p38/MAPK signaling pathway. We examined gene alterations related to this pathway using hypoxic cell models and employed p38 inhibitors to verify protein changes. Our findings in vitro were then confirmed in the NED rat model.

RESULTS

Nerve injury led to reduced Ach receptors and associated gene expression. Experimentally, Ach was shown to counteract CCMSC apoptosis and muscle protein degradation via the p38/MAPK pathway. Inhibition of the Ach degradation pathway demonstrated a capacity to slow NED progression in vivo.

DISCUSSION AND CONCLUSION

Activation of Ach receptors may decelerate denervation-induced cavernosal muscle atrophy, suggesting a potential therapeutic approach for NED. This study highlights the crucial role of the Ach/p38/MAPK axis in the pathophysiology of penis smooth muscle atrophy and its broader implications in managing NED and male erectile dysfunction.

IL-17A exacerbates corpus cavernosum fibrosis and neurogenic erectile dysfunction by inducing CSMC senescence via the mTORC2-ACACA pathway

BACKGROUND

Neurogenic erectile dysfunction, characterized by neurological repair disorders and progressive corpus cavernosum fibrosis (CCF), is an unbearable disease with limited treatment success. IL-17A exhibits a complex role in tissue remodelling. Nevertheless, the precise role and underlying mechanisms of IL-17A in CCF under denervation remain unclear.

METHODS

PCR array was employed to identified differentially expressed genes between neurogenic ED and normal rats. IL-17A expression and its main target cells were analyzed using Western blotting, immunofluorescence and immunohistochemistry. The phenotypic regulation of IL-17A on corpus cavernosum smooth muscle cells (CSMCs) was evaluated by cell cycle experiments and SA-β-Gal staining. The mechanism of IL-17A was elucidated using non-target metabolomics and siRNA technique. Finally, IL-17A antagonist and ABT-263 (an inhibitor of B-cell lymphoma 2/w/xL) were utilized to enhance the therapeutic effect in a rat model of neurogenic ED.

RESULTS

IL-17A emerged as the most significantly upregulated gene in the corpus cavernosum of model rats. It augmented the senescence transformation and fibrotic response of CSMCs, and exhibited a strong correlation with CCF. Mechanistically, IL-17A facilitated CCF by activating the mTORC2-ACACA signalling pathway, upregulating of CSMCs lipid synthesis and senescence transition, and increasing the secretion of fibro-matrix proteins. In vivo, the blockade of IL-17A-senescence signalling improved erectile function and alleviated CCF in neurogenic ED.

CONCLUSIONS

IL-17A assumes a pivotal role in denervated CCF by activating the mTORC2-ACACA signalling pathway, presenting itself as a potential therapeutic target for effectively overcoming CCF and erection rehabilitation in neurogenic ED.

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.

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.

The role of Cistanches Herba and its ingredients in improving reproductive outcomes: A comprehensive review

BACKGROUND

Infertility patients account for an astonishing proportion of individuals worldwide. Due to its complex etiology and challenging treatment, infertility has imposed significant psychological and economic burdens on many patients. C. Herba (Cistanche tubulosa (Schenk) Wight and Cistanche deserticola Ma), renowned as one of the most prominent Chinese herbal medicines (CHMs), is abundant in diverse bioactive compounds that exhibit therapeutic effects on many diseases related to oxidative stress (OS) and disorders of sex hormone levels.

OBJECTIVE

Due to the limited drugs currently used in clinical practice to improve reproductive outcomes and their inevitable side effects, developing safe and effective new medications for infertility is of significance. This article comprehensively reviewed the phytochemicals of C. Herba, focusing on their efficacy and mechanisms on infertility and their safety for the first time, aiming to offer valuable insights for the development and application of C. Herba, and for developing novel strategies for treating infertility.

METHODS

We used "Cistanche" and its known bioactive components in combination with "sperm", "testicles", "epididymis", "ovaries", "uterus", and "infertility" as keywords to search in PubMed, Web of Science, Scopus and CNKI up to November 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline was followed.

RESULTS

The therapeutic effects of C. Herba on infertility are mainly attributed to echinacoside (ECH), verbascoside (VB), salidroside (SAL), polysaccharides, and betaine. They can effectively improve spermatogenic dysfunction, gonadal dysfunction and erectile dysfunction (ED) by exerting anti-oxidation, sex hormones regulation and anti-hypoxia. Moreover, they can also improve premature ovarian failure (POF), ovarian and uterine cancer, oocyte maturation by exerting anti-oxidation, anti-apoptosis, and anti-cancer. C. Herba and its active ingredients also exhibit pleasing safety.

CONCLUSION

C. Herba is a promising source of natural medicine for infertility. Additionally, compared to current therapeutic drugs, its favorable safety also supports its development as a nutritional supplement. However, high-quality clinical studies are required to validate its effectiveness for the development of novel therapeutic strategies.

Cldn4 overexpression promotes penile cavernous smooth muscle cell fibrotic response via the JNK signaling pathway

BACKGROUND

Erectile dysfunction (ED), defined as the inability to achieve or maintain a penile erection sufficient to satisfy sexual behavior, is prevalent worldwide.

AIM

Using previous research, bioinformatics, and experimental confirmation, we aimed to discover genes that contribute to ED through regulating hypoxia in corpus cavernosum smooth muscle cells (CCSMCs).

METHODS

We used the Gene Expression Omnibus to acquire the sequencing data of the corpus cavernosum transcriptome for diabetic ED and nerve injury type ED rats. We intersected the common differentially expressed genes. Further verification was performed using single cell sequencing. Real-time quantitative polymerase chain reaction and immunofluorescence were used to investigate whether the differentially expressed genes are found in the corpus cavernosum. We used induced hypoxia to assess cell viability changes, and we developed a lentivirus overexpressing Cldn4 for in vitro and in vivo experiments to measure changes in JNK signaling, fibrosis, hypoxia, and erectile function.

OUTCOMES

Our results indicate that targeting the JNK pathway and decreasing local hypoxia may be better options for therapeutic intervention to improve erectile function.

RESULTS

We identified Cldn4 and found its expression increased in the corpora cavernosa of the 2 datasets. In addition, we found that hypoxia can increase the expression of Cldn4, activate the JNK signaling pathway, and exacerbate fibrosis in CCSMCs. Cldn4 overexpression in CCSMCs activated the JNK signaling pathway and increased fibrotic protein expression. Last, rat corpus cavernosum overexpressing Cldn4 activated the JNK signaling pathway, increased local fibrosis, and impaired erectile function.

CLINICAL IMPLICATIONS

Through bioinformatics and in vitro and in vivo experiments, we found that Cldn4 has a negative effect on ED, and targeting Cldn4 may provide new ideas for ED treatment.

STRENGTHS AND LIMITATIONS

Although we have identified Cldn4 as a potential target for ED treatment, we have only conducted preliminary validation on CCMSCs, and we still need to further validate in other cell lines.

CONCLUSION

CCSMC hypoxia leads to increased Cldn4, in both nerve injury and diabetic ED rat models, and promotes fibrosis by activating the JNK signaling pathway.

Myocardin Reverses Hypoxia-Inducible Factor-1α Mediated Phenotypic Modulation of Corpus Cavernosum Smooth Muscle Cells in Hypoxia Induced by Cobalt Chloride

PURPOSE

We aimed to investigate the mechanism of phenotypic transformation of corporal cavernosum smooth muscle cells (CCSMCs) under hypoxic conditions in vitro.

MATERIALS AND METHODS

In this study, a hypoxia model was established using cobalt chloride (CoCl₂). CCSMCs were treated with different concentrations of CoCl₂ for varying time periods, and cell viability was assessed. Hypoxia-inducible factor-1α (HIF-1α), myocardin (Myocd) and phenotypic markers were detected in the CCSMCs. We also transfected the CCSMCs with si-HIF-1α and Ad-Myocd and evaluated the effects on phenotypic modulation of CCSMCs and the relationship between HIF-1α and Myocd was evaluated.

RESULTS

CoCl₂ inhibited the viability of CCSMCs in a dose- and time-dependent manner, and treatment with 300 µM CoCl₂ for 48 hours were the optimal conditions for establishing the hypoxia model. The results showed increased expression levels of HIF-1α and osteopontin and decreased Myocd, alpha-smooth muscle actin, and calponin levels in CCSMCs under hypoxia. HIF-1α knockdown reversed hypoxia-induced phenotypic transformation with elevated Myocd expression. Overexpression of Myocd also reversed the effect of hypoxia on the phenotypic switch, but did not affect HIF-1α expression.

CONCLUSIONS

Our findings showed that HIF-1α was involved in the effect of hypoxia induced by CoCl₂ on CCSMC phenotypic modulation, and Myocd overexpression could inhibit this process. Thus, Myocd might be a potential therapeutic target for erectile dysfunction under hypoxia or HIF-1α activation.

Molecular pathogenesis and treatment of cavernous nerve injury-induced erectile dysfunction: A narrative review

Introduction: Erectile dysfunction (ED) is a common complication after radical prostatectomy (RP), and it seriously affects the quality of life in patients and their partners. The primary trigger of postoperative ED is surgical injury to the cavernous nerves that control penile erection and run along the anterolateral aspect of the prostate. Despite the introduction and ongoing innovation of nerve-sparing techniques, a significant number of patients still suffer from moderate cavernous nerve injury (CNI), which is thought to be transient and reversible. Therefore, early postoperative penile rehabilitation therapy may salvage patients’ erectile function by promoting cavernous nerve regeneration and preventing penile structural alterations.

Aims: To present a comprehensive overview of the current molecular pathogenesis of CNI-induced ED, as well as novel therapeutic strategies and their potential mechanisms.

Methods: A literature search was performed using PubMed. Search terms included erectile dysfunction, cavernous nerve injury, pathogenesis, pathway, and treatment.

Results: The NOS/NO pathway, oxidative stress-related pathway, RhoA/ROCK pathway, transforming growth factor-β (TGF-β), sonic hedgehog (Shh), and hydrogen sulfide (H2S) are involved in the molecular pathogenesis of CNI-induced ED. Multiple neurotrophins, including brain-derived nerve growth factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and neurturin (NTN), were found to promote cavernous nerve regeneration. Emerging therapeutic approaches can be roughly summarized into four categories, namely small molecule and drug, stem cell-based therapy (SCT), micro-energy therapy and platelet-rich plasma (PRP) therapy.

Conclusion: These pathways collectively lead to the irreversible damage to the penile structure after CNI. The combined early rehabilitation strategies of promoting upstream nerve regeneration and recovering abnormal molecular signals of downstream penis are presumed to save patients’ erectile function after RP. In future studies, the cross-talk between these molecular pathways needs to be further clarified, and the questions of how denervation injury induces the molecular alterations in the penis also need to be addressed.

Phenotypic modulation of vascular smooth muscle cells in the corpus spongiosum surrounding the urethral plate in hypospadias

Hypospadias is an abnormal ventral development of the penis caused by incomplete virilization of the male genital tubercle. This study investigated the phenotypic modulation of vascular smooth muscle cells (VSMCs) in the corpus spongiosum surrounding the urethral plate in hypospadias. The urethral corpus spongiosum tissue was collected for HE, Masson and α-SMA immunohistochemical staining. Spongiosum VSMCs were cultured and identified by α-SMA fluorescence. qRT-PCR and Western blotting and fluorescence were performed. The results showed that the vascular lumen of the corpus spongiosum around the urethral plate was larger and that the vascular smooth muscle layer was thicker in hypospadias. The expression of the contractile markers α-SMA and Calponin 1 in VSMCs was decreased, the expression of the synthetic marker OPN was increased, and the transcription of the phenotypic switching factors SRF and MYOCD was decreased. The expression of Ki67, PCNA and BAX was increased, and the expression of Bcl-2 was decreased. The phenotype of corpus spongiosum VSMCs in hypospadias changed from the contractional type to the synthetic type. This phenotypic modulation was associated with increased proliferation and apoptosis rates. SRF and MYOCD may be the main factors mediating the phenotypic modulation of urethral corpus spongiosum VSMCs.

CNN1 Represses Bladder Cancer Progression and Metabolic Reprogramming by Modulating HIF-1α Signaling Pathway

Bladder cancer (BC) is the second most common urinary system malignant tumor around the whole world. It has been reported that CNN1 was lowly expressed in BC tissues. However, the mechanisms of CNN1 on BC cells were unclear. Herein, we aimed to probe the specific influences of CNN1 on BC pathogenesis. First, the expression level and prognostic ability of CNN1 in BC patients were surveyed. Then, CNN1 overexpression was executed to exhibit the influences of CNN1 on BC cells. The real-time PCR and Western blotting were employed to detect by the mRNA and protein expression levels. CCK8 assay was utilized to examine cell proliferation, and transwell assay was executed to test cell invasion and migration. The corresponding kits were utilized to detect glucose absorption, lactate secretion, and ATP level. BC cells overexpressing CNN1 were utilized to establish a nude mouse xenograft tumor model, and the tumor volume and tumor weight were detected. Nude mouse tumor tissues were used for immunohistochemical experiments to test the expression levels of Ki-67 and CNN1. The outcomes indicated that CNN1 was significantly lowly expressed in BC tissues and cells. Besides, low expression of CNN1 might be concerned with poor prognosis. Moreover, overexpression of CNN1 repressed the proliferation, invasion, and migration of BC cells. Furthermore, CNN1 overexpression decreased the protein levels of glycolysis-related protein GLUT1 (glucose transporter 1), pyruvate kinase M2 (PKM2), and LDHA (lactate dehydrogenase A). Then, the decreased mRNA and protein levels of HIF-1α and PDK1 were identified after CNN1 overexpression. The in vivo assays verified the effects of aberrant expression of CNN1 in mice with BC. In conclusion, these findings suggested that CNN1 might modulate BC progression through activating HIF-1α pathway and CNN1 might be a promising marker for BC diagnosis.

Long noncoding RNA H19 promotes the apoptosis of corpus cavernsum smooth muscle cells after cavernosal nerve injury via JNK signalling pathway

JNK/ Bcl-2/ Bax pathway participates in corpus cavernosal smooth muscle cells apoptosis during early period after cavernosal nerve (CN) crush injury (CNCI). Nevertheless, the regulation mechanisms of long noncoding RNA H19 in apoptosis during early stage after CN injury are still poorly understood. The rats in sham group were not direct injury to the CNs. The rats in CNCI group were performed to bilateral CN crush injury. The ICP/MAP rate and smooth muscle content were significantly lower than that in the sham group. Primary CCSMCs were prepared from the tissues samples after completing erectile function detection. Phosphorylated-JNK level was increased significantly, and the expression of Bax and Bcl-2 was elevated and declined in CNCI group respectively. Except for Bcl-2, the mRNA levels of H19, JNK and Bax were significantly increased in CNCI group. After H19 siRNA transfection, for the mRNA and protein levels, JNK and Bax were declined, while Bcl-2 was enhanced. LncRNA H19 might be involved in regulation of Bcl-2, Bax via JNK signalling pathway in CCSMCs apoptosis after CN injury.

CNN1 regulates the DKK1/Wnt/β-catenin/c-myc signaling pathway by activating TIMP2 to inhibit the invasion, migration and EMT of lung squamous cell carcinoma cells

The present study aimed to investigate the effect of calponin 1 (CNN1) on the invasion and migration of lung squamous cell carcinoma (LUSC) cells and the associations between CNN1, tissue inhibitor of metalloproteinases 2 (TIMP2), Dickkopf-1 (DKK1) and the Wnt/β-catenin/c-myc signaling pathway. The expression levels of CNN1 and TIMP2 in LUSC cells and the association between CNN1 and TIMP2 were predicted using the GEPIA database. The cells were transiently transfected to overexpress CNN1, which resulted in inhibition of DKK1 and TIMP2 expression levels. Wound healing and Transwell assays were used to detect the invasive and migratory abilities of LUSC cells. Reverse transcription-quantitative PCR and western blotting were used to investigate the expression levels of CNN1, MMP2, MMP9, E-cadherin, N-cadherin (N-cad), SLUG, DKK1, β-catenin and c-myc. The expression levels of N-cad were detected using immunofluorescence staining. The results indicated that overexpression of CNN1 inhibited the invasion and migration of NCI-H2170 cells. Inhibition of DKK1 reversed this change and the expression levels of β-catenin and c-myc were upregulated, whereas the expression levels of DKK1 were downregulated with a concomitant inhibition of TIMP2. In summary, these results demonstrated that CNN1 regulated the DKK1/Wnt/β-catenin/c-myc signaling pathway by activating TIMP2 to inhibit the invasion, migration and epithelial-to-mesenchymal transition of LUSC cells.

Alterations in the phosphodiesterase type 5 pathway and oxidative stress correlate with erectile function in spontaneously hypertensive rats

To explore how alterations in the phosphodiesterase type 5 (PDE5) signalling pathway and oxidative stress correlate with changes in the expression of relaxation and contraction molecules and erectile dysfunction (ED) in the corpus cavernosum smooth muscle (CCSM) of spontaneously hypertensive rats (SHR). In this study, SHR and Wistar‐Kyoto (WKY) rats were used. Erectile function was determined by apomorphine test and electrical stimulation (ES) of cavernous nerve. Masson's trichrome staining and confocal microscopy were performed. Nitric oxide synthase (NOS), PDE5, phosphorylated‐PDE5 and α1‐adrenergic receptor (α1AR) were determined by RT‐PCR and Western blotting while oxidative stress in CC was determined by colorimetric analysis. SHR exhibited obvious ED. CC of SHR showed less SM but more collagen fibres. The expression of NOS isoforms in SHR was significantly decreased while all α1AR isoforms were increased. In addition, PDE5 and phosphorylated‐PDE5 were down‐regulated and its activity attenuated in the hypertensive rats. Meanwhile, the SHR group suffered oxidative stress, which may be modulated by endoplasmic reticulum stress and NADPH oxidase up‐regulation. Dysregulation of NOS and α1AR, histological changes and oxidative stress in CC may be associated with the pathophysiology of hypertension‐induced ED. In addition, PDE5 down‐regulation may lead to the decreased efficacy of PDE5 inhibitors in some hypertensive ED patients and treatment of oxidative stress could be used as a new therapeutic target for this type of ED.

Mitochondrial ATP synthase regulates corpus cavernosum smooth muscle cell function in vivo and in vitro

Adenosine triphosphate (ATP) levels are closely associated with diabetes-related erectile dysfunction (DMED). Mitochondrial ATP synthase serves a key role in ATP production. The present study aimed to investigate the relationship between F₁-ATP synthase and DMED in vivo and in vitro. The F₁-ATP synthase expression levels in corpus cavernosum tissues from rats with DMED were examined. F₁-ATP synthase expression was found to be lower in corpus cavernosum tissues from rats with DMED compared with healthy controls, suggesting a role for ATP synthase under high glucose conditions. In addition, the present study also demonstrated that hyperglycemia could downregulate F₁-ATP synthase expression in rat corpus cavernosum smooth muscle cells (CCSMCs) in vitro. The overexpression of F₁-ATP synthase in CCSMCs influenced the phenotypic CCSMC transformation, upregulated eNOS expression, increased cGMP levels and reduced CCSMC apoptosis under high glucose in vitro. In conclusion, the present study indicates that the upregulation of mitochondrial ATP synthase expression may improve CCSMC function, suggesting that mitochondrial ATP synthase could serve as a potential therapeutic target for the treatment of DMED.

Novel noninvasive quantification of penile corpus cavernosum lesions in hyperlipidemia-induced erectile dysfunction in rabbits by two-dimensional shear-wave elastography

Structural alterations in fibroelastic components of the penile corpus cavernousum (CC) may impair its compliance, resulting in venous leakage and erectile dysfunction (ED). Our study evaluated the effectiveness of noninvasive two-dimensional shear-wave elastography (2-D SWE) in quantifying penile CC lesions in rabbits with hyperlipidemia-induced ED. A total of 12 New Zealand white rabbits were randomly divided into two groups. Six were fed a high-cholesterol diet containing 2% cholesterol and 8.5% lard for 10 weeks and the other six were fed normal diet as controls. We measured the shear-wave elastic quantitative (SWQ) value of penile CC by 2-D SWE. Erectile function was investigated by intracavernous injection of papaverine, and immunohistochemical (IHC) staining and the western blot analysis to determine the penile CC lesions. After 10 weeks, the SWQ values obtained from penile CC were remarkably higher in the high-cholesterol-fed compared with the control group, and the ΔICP (ICP plateau minus ICP baseline)/MAP (ICP: intracavernous pressure, MAP: mean arterial pressure) was markedly decreased. The IHC staining and western blot revealed extracellular matrix (ECM) accumulation in penile cavernous tissues, and the smooth muscle cell (SMC) phenotypic transition was affected, as indicated by reduced alpha-smooth muscle actin and calponin-1 expression and increased phospho-myosin light chain₂₀ (p-MLC₂₀)/MLC₂₀ and osteopontin expression. Hyperlipidemia resulted in ECM accumulation accompanied with SMC phenotypic transition in penile CC and impaired the erectile function eventually. These might, in turn, lead to variations in the SWQ values. It suggests that 2-D SWE may be a novel, noninvasive and effective approach that distinguishes penile CC lesions secondary to hyperlipidemia from normal.

Salidroside Attenuates Hypoxia-Induced Expression of Connexin 43 in Corpus Cavernosum Smooth Muscle Cells

<b><i>Introduction:</i></b> Connexin 43 (Cx43) is the major component of gap junction in corpus cavernosum smooth muscle, which allows rapid intercellular communication. Cx43 coordinates corpus cavernosum smooth muscle cells and ensures erectile function. The role of hypoxia in Cx43 dysfunction resulting in erectile dysfunction has not been well studied, and salidroside has shown cell protective effects under hypoxia. <b><i>Objective:</i></b> We aimed to investigate the protective role of salidroside and the underlying mechanisms in hypoxia-induced dysfunction of Cx43. <b><i>Methods:</i></b> Corpus cavernosum smooth muscle cells prepared from young male Sprague-Dawley rats were pretreated with or without salidroside and exposed to hypoxic condition for 48 h. The cell viability, expression of hypoxia-inducible factor-1α (HIF-1α) and Cx43, and Ca²⁺ signals were investigated. <b><i>Results:</i></b> Pretreatment with salidroside attenuated loss of hypoxia-induced cell viability markedly and could downregulate the HIF-1α protein expression under hypoxia. Moreover, the expression of Cx43 was significantly increased by hypoxia but was decreased with salidroside pretreatment. The salidroside pretreated group exhibited enhanced release of intracellular Ca²⁺ in corpus cavernosum smooth muscle cells compared with the hypoxia group after stimulation. <b><i>Conclusion:</i></b> Salidroside has a protective effect against hypoxia-induced damage to corpus cavernosum smooth muscle cells.

Hypoxia-Induced Phenotypic Transformation of Corpus Cavernosum Smooth Muscle Cells After Cavernous Nerve Crush Injury by Down-Regulating P38 Mitogen-Activated Protein Kinase Expression

INTRODUCTION

Cavernosal nerve (CN) injury is commonly caused by radical prostatectomy surgery, and it might directly lead to erectile dysfunction (ED). Currently, the role of mitogen-activated protein kinase (MAPK) family proteins in phenotypic transformation of corpus cavernosum smooth muscle cell (CCSMC) after CNs injury is poorly understood.

AIM

To investigate the role of p38 MAPK in hypoxia-induced phenotypic transformation of CCSMCs after CN injury.

METHODS

In total, 20 Sprague-Dawley rats (male and 8 weeks of age) were randomly divided into 2 groups, including a sham group and CNCI group. In the sham group, rats were sham-operated by identifying 2 CNs without causing direct damage to the CNs. In the CNCI group, rats were subjected to bilateral CN crush injury. CCSMCs were isolated from the normal corpus cavernosum tissues of the Sprague-Dawley rat and then cultured in 21% or 1% O₂ concentration context for 48 hours.

MAIN OUTCOME MEASURES

Intracavernous pressure/mean arterial pressure were analyzed to measure erectile response. The impact of hypoxia on penile pathology, as well as the expression of extracellular signal-regulated kinases, the c-Jun NH2-terminal kinase, and p38 MAPK, were analyzed.

RESULTS

Compared with the sham group, the intracavernous pressure/mean arterial pressure rate and α-smooth muscle actin expression of CNCI group were decreased significantly (P = .0001; P = .016, respectively), but vimentin expression was significantly increased (P = .023). Phosphorylated p38 level in CNCI group was decreased significantly (P = .017; sham: 0.17 ± 0.005; CNCI: 0.14 ± 0.02). The CCSMCs in the normoxia group were long fusiform, whereas the morphology of CCSMCs in the hypoxia group became hypertrophic. After hypoxia for 48 hours, the expression of α-smooth muscle actin and phosphorylated p38 MAPK was decreased significantly (P = .01; P = .024, normoxia: 0.66 ± 0.18, hypoxia: 0.26 ± 0.08, respectively), and the expression of hypoxia-inducible factor-1α and collagen I was increased significantly in hypoxia group (P = .04; P = .012, respectively).

CONCLUSIONS

Hypoxia induced the phenotypic transformation of CCSMCs after CNCI might be associated with the downregulation of phosphorylated p38 MAPK. Chen S, Huang X, Kong X, et al. Hypoxia-Induced Phenotypic Transformation of Corpus Cavernosum Smooth Muscle Cells After Cavernous Nerve Crush Injury by Down-Regulating p38 Mitogen-Activated Protein Kinase Expression. Sex Med 2019;7:433-440.

PDGF-mediated PI3K/AKT/β-catenin signaling regulates gap junctions in corpus cavernosum smooth muscle cells

Erectile dysfunction (ED) is the most common sexual disorder that men report to healthcare providers. Gap junctions (GJs) are thought to be responsible for synchronous shrinkage of corpus cavernosum smooth muscle cells (CCSMCs), and play thus an important role in the maintenance of an erection. Hypoxia has been suggested as a pathological mechanism underlying ED. Here we demonstrate that hypoxia increased the expression of platelet-derived growth factor (PDGF) and the main GJ component connexin (Cx)43 in CCSMCs. Inhibiting PDGF receptor (PDGFR) activity decreased Cx43 expression. Treatment with different concentrations of PDGF increased the levels of phosphorylated protein kinase B (AKT), β-catenin, and Cx43, whereas inhibition of PDGFR or activation of phosphatidylinositol 3 kinase (PI3K)/AKT signaling altered β-catenin and Cx43 expression. Meanwhile, silencing β-catenin resulted in the downregulation of Cx43. These results demonstrate that PDGF secretion by CCSMCs and vascular endothelial cells is enhanced under hypoxic conditions, leading to increased Cx43 expression through PI3K/AKT/β-catenin signaling and ultimately affecting GJ function in ED. Thus, targeting this pathway is a potential therapeutic strategy for the treatment of ED.

The effects of miRNA-145 on the phenotypic modulation of rat corpus cavernosum smooth muscle cells

To investigate the effect of miR-145 on the phenotypic modulation in rat corpus cavernosum smooth muscle cells. Corpus cavernosum smooth muscle cells were treated with either miR-145 mimics or miR-145 negative control. Cell proliferation were analyzed by the MTS assay and colony formation assay. Wound healing assay were performed to detect the effect of miR-145 on cell migration. The mRNA and protein levels of phenotype marker proteins were assessed by quantitative real-time polymerase chain reaction and western blotting. The intracavernosal pressure and mean arterial pressure were measured to assess erectile function at one month after the injection of platelet-derived growth factor-BB and miR-145. Our results showed that miR-145 inhibited the proliferation and migration of cavernosal smooth muscle cells. Smooth muscle cell phenotypic markers were also affected by overexpression of miR-145, as indicated by the increase in α-smooth muscle actin, calponin and smooth muscle myosin heavy chain expression. Moreover, significantly attenuated erectile function was observed in the platelet-derived growth factor-BB group as compared with the platelet-derived growth factor-BB+miR-145 group. These findings indicated that miR-145 regulate phenotypic modulation of corpus cavernosum smooth muscle cells.

Effect of Testosterone on the Phenotypic Modulation of Corpus Cavernosum Smooth Muscle Cells in a Castrated Rat Model

OBJECTIVE

To investigate the effect of testosterone (T) on the phenotypic modulation of corpus cavernosum smooth muscle (CCSM) cells in a castrated rat model.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats were randomly divided into 3 groups: control, castration, and castration with T supplementation (castration + T). Erectile function, histologic change, and biochemical markers were assessed for phenotypic modulation of CCSM cells in corporal tissue. Moreover, the primary rat CCSM cells were isolated and examined by Western blot analysis.

RESULTS

Our data showed that serum T level, mean weight of the body, erectile function, and smooth muscle-to-collagen ratio were significantly decreased in the castration group compared with those in the control and castration + T groups. The expressions of CCSM cells' phenotypic markers, such as α-smooth muscle actin, calponin, and smooth muscle myosin heavy chain 11, were markedly lower, whereas osteopontin protein expression was significantly higher in castrated rats than in control and castrated + T rats. In addition, the immunofluorescence staining of α-smooth muscle actin and calponin markedly decreased in the primary CCSM cells of the castrated rats compared with the intensity of the control and the castration + T rats.

CONCLUSION

CCSM cells undergo phenotype modulation in castrated rats, whereas T reversed the alterations. T may play a key role in the phenotype modulation of CCSM cells.

The platelet-derived growth factor receptor/STAT3 signaling pathway regulates the phenotypic transition of corpus cavernosum smooth muscle in rats

Erectile dysfunction (ED) is a common clinical disease that is difficult to treat. We previously found that hypoxia modulates the phenotype of primary corpus cavernosum smooth muscle cells (CCSMCs) in rats, but the underlying molecular mechanism is still unknown. Platelet-derived growth factor receptor (PDGFR)-related signaling pathways are correlated with cell phenotypic transition, but research has been focused more on vascular smooth muscle and tracheal smooth muscle and less on CCSMCs. Here, we investigated the role of PDGFR-related signaling pathways in penile CCSMCs, which were successfully isolated from rats and cultured in vitro. PDGF-BB at 5, 10, or 20 ng/ml altered CCSMC morphology from the original elongated, spindle shape to a broader shape and promoted the synthetic phenotype and expression of the related proteins vimentin and collagen-I, while inhibiting the contractile phenotype and expression of the related proteins smooth muscle (SM) α-actin (α-SMA) and desmin. Inhibition of PDGFR activity via siRNA or the PDGFR inhibitor crenolanib inhibited vimentin and collagen-I expression, increased α-SMA and desmin expression, and considerably inhibited serine-threonine protein kinase (AKT) and signal transducer and activator of transcription 3 (STAT3) phosphorylation. STAT3 knockdown promoted the contractile phenotype, inhibited vimentin and collagen-I expression, and increased α-SMA and desmin expression, whereas AKT knockdown did not affect phenotype-associated proteins. STAT3 overexpression in CCSMC cells weakened the suppressive effect of PDGFR inhibition on the morphology and phenotypic transformation induced by PDGF-BB. Through activation of the PDGFR/STAT3 signaling pathway, PDGF promoted the synthetic phenotype transition; thus, regulation of this pathway might contribute to ED therapy.

Potential microRNA biomarkers for acute ischemic stroke

Acute ischemic stroke is a significant cause of high morbidity and mortality in the aging population globally. However, current therapeutic strategies for acute ischemic stroke are limited. Atherosclerotic plaque is considered an independent risk factor for acute ischemic stroke. To identify biomarkers for carotid atheromatous plaque, bioinformatics analysis of the gene microarray data of plaque and intact tissue from individuals was performed. Differentially expressed genes (DEGs) were identified using the Multtest and Limma packages of R language, including 56 downregulated and 69 upregulated DEGs. Enriched microRNA (miRNA or miR) DEGs networks were generated using WebGestalt software and the STRING databases, and the miRNAs were validated using serum from acute ischemic stroke patients with reverse transcription quantitative PCR (RT‑qPCR). Four confirmed differentially expressed miRNAs (miR‑9, ‑22, ‑23 and ‑125) were associated with 28 upregulated DEGs, and 7 miRNAs (miR‑9, ‑30, ‑33, ‑124, ‑181, ‑218 and ‑330) were associated with 25 downregulated DEGs. Gene ontology (GO) function suggested that the confirmed miRNA‑targeted DEGs predominantly associated with signal transduction, the circulatory system, biological adhesion, striated muscle contraction, wound healing and the immune system. The confirmed miRNA‑targeted genes identified serve as potential therapeutic targets for acute ischemic stroke.