Neurovascular dysfunction associated with erectile dysfunction persists after long-term recovery from simulations of weightlessness and deep space irradiation.

There has been growing interest within the space industry for long-duration manned expeditions to the Moon and Mars. During deep space missions, astronauts are exposed to high levels of galactic cosmic radiation (GCR) and microgravity which are associated with increased risk of oxidative stress and endothelial dysfunction. Oxidative stress and endothelial dysfunction are causative factors in the pathogenesis of erectile dysfunction, although the effects of spaceflight on erectile function have been unexplored. Therefore, the purpose of this study was to investigate the effects of simulated spaceflight and long-term recovery on tissues critical for erectile function, the distal internal pudendal artery (dIPA), and the corpus cavernosum (CC). Eighty-six adult male Fisher-344 rats were randomized into six groups and exposed to 4-weeks of hindlimb unloading (HLU) or weight-bearing control, and sham (0Gy), 0.75 Gy, or 1.5 Gy of simulated GCR at the ground-based GCR simulator at the NASA Space Radiation Laboratory. Following a 12-13-month recovery, ex vivo physiological analysis of the dIPA and CC tissue segments revealed differential impacts of HLU and GCR on endothelium-dependent and -independent relaxation that was tissue type specific. GCR impaired non-adrenergic non-cholinergic (NANC) nerve-mediated relaxation in the dIPA and CC, while follow-up experiments of the CC showed restoration of NANC-mediated relaxation of GCR tissues following acute incubation with the antioxidants mito-TEMPO and TEMPOL, as well as inhibitors of xanthine oxidase and arginase. These findings indicate that simulated spaceflight exerts a long-term impairment of neurovascular erectile function, which exposes a new health risk to consider with deep space exploration.

Evidence of an excitatory purinergic innervation in mouse corpus cavernosum smooth muscle.

BACKGROUND: Evidence suggests that the corpus cavernosum smooth muscle (CCSM) cells of several species, including humans, express purinergic P2X receptors, but it is not known if the corpus cavernosum has an excitatory purinergic innervation. AIM: In this study we aimed to determine if the mouse CCSM has a functional purinergic innervation. METHODS: Mouse CCSM myocytes were enzymatically isolated and studied using the perforated patch configuration of the patch clamp technique. Isometric tension was measured in whole cavernosum tissue subjected to electrical field stimulation (EFS) to evoke nerve-mediated responses. OUTCOMES: The mouse CCSM myocytes expressed P2X1 receptors, and adenosine triphosphate (ATP) evoked inward currents in these cells. In addition, P2X1-mediated contractions were recorded in whole tissue in response to EFS. RESULTS: In cells held under a voltage clamp at -60 mV, ATP (1 µm) evoked large inward currents (mean approximately 900 pA). This current rapidly declined but was repeatable at 8-minute intervals. α,ß-methylene ATP (10 µM), an agonist of P2X1 and P2X3 receptors, caused a similar current that also rapidly declined. Desensitization to α,ß-methylene ATP negated the effect of ATP, but the ATP effect was restored 8 minutes after washout of α,ß-methylene ATP. The effect of ATP was reversibly blocked by NF449 (1 µm), a selective antagonist of P2X1 receptors. In isometric tension experiments electrical field stimulation (EFS) at 0.5-8 Hz evoked frequency-dependent contractions in the presence of l-nitro arginine (l-NO-Arg) (100 µm). When phentolamine (3 µm) and atropine (1 µm) were applied, there remained a nonadrenergic, noncholinergic component of the response to EFS, consisting mainly of a transient contraction. This was significantly reduced by NF449 (1 µm). Finally, in immunocytochemistry experiments, isolated CCSM myocytes stained positively when exposed to an antibody raised against P2X1 receptors. CLINICAL IMPLICATIONS: Previous studies have shown that P2X1 receptors in CCSM are upregulated in diabetes. These findings, taken together with the functional evidence presented here, indicate that P2X1 receptors may provide an alternative therapeutic target for treatment of erectile dysfunction in patients with diabetes, which is known to be relatively resistant to treatment with phosphodiesterase 5 inhibitors. STRENGTHS AND LIMITATIONS: Strengths of this study are the use of a combination of functional experiments (patch clamp) and immunocytochemical analyses to show expression of P2X1 receptors on CCSM myocytes while also performing functional experiments to show that stimulation these receptors results in contraction of CCSM. A limitation of this study was the use of animal rather than human tissue. CONCLUSION: This investigation provides evidence that mouse corpus cavernosum smooth muscle cells express P2X1 receptors and that these receptors are involved in mediating part of the contractile response to nerve stimulation evoked by EFS.

Polystyrene nanoplastics exposure causes erectile dysfunction in rats.

Polystyrene nanoplastics (PS-NPs), emerging and increasingly pervasive environmental contaminants, have the potential to cause persistent harm to organisms. Although previous reports have documented local accumulation and adverse effects in a variety of major organs after PS-NPs exposure, the impact of PS-NPs exposure on erectile function remains unexplored. Herein, we established a rat model of oral exposure to 100 nm PS-NPs for 28 days. To determine the best dose range of PS-NPs, we designed both low-dose and high-dose PS-NPs groups, which correspond to the minimum and maximum human intake doses, respectively. The findings indicated that PS-NPs could accumulate within the corpus cavernosum and high dose but not low dose of PS-NPs triggered erectile dysfunction. Moreover, the toxicological effects of PS-NPs on erectile function include fibrosis in the corpus cavernous, endothelial dysfunction, reduction in testosterone levels, elevated oxidative stress and apoptosis. Overall, this study revealed that PS-NPs exposure can cause erectile dysfunction via multiple ways, which provided new insights into the toxicity of PS-NPs.

PKC Inhibition Improves Human Penile Vascular Function and the NO/cGMP Pathway in Diabetic Erectile Dysfunction: The Role of NADPH Oxidase.

Erectile dysfunction (ED) is a frequent and difficult-to-treat condition in diabetic men. Protein kinase C (PKC) is involved in diabetes-related vascular and cavernosal alterations. We aimed to evaluate the role of PKC in endothelial dysfunction and NO/cGMP impairment associated with diabetic ED in the human corpus cavernosum (CC) and penile resistance arteries (PRAs) and the potential mechanisms involved. Functional responses were determined in the CC and PRAs in patients with non-diabetic ED and diabetic ED undergoing penile prosthesis insertion. PKC activator 12,13-phorbol-dibutyrate (PDBu) impaired endothelial relaxations and cGMP generation in response to acetylcholine in the CC from non-diabetic ED. PDBu also impaired responses to a PDE5 inhibitor, sildenafil, in non-diabetic ED patients. Conversely, a PKC inhibitor, GF109203X, improved endothelial, neurogenic, and PDE5-inhibitor-induced relaxations and cGMP generation only in the CC in diabetic ED patients. Endothelial and PDE5-inhibitor-induced vasodilations of PRAs were potentiated only in diabetes. Improvements in endothelial function in diabetes were also achieved with a specific inhibitor of the PKCß2 isoform or an NADPH-oxidase inhibitor, apocynin, which prevented PDBu-induced impairment in non-diabetic patients. PKC inhibition counteracted NO/cGMP impairment and endothelial dysfunction in diabetes-related ED, potentially improving response to PDE5 inhibition.

Novel erectile analyses revealed augmentable penile Lyve-1, the lymphatic marker, expression.

Purpose: The pathophysiology of penis extends to erectile dysfunction (ED) to conditions including sexually transmitted diseases (STDs) and cancer. To date, there has been little research evaluating vascular drainage from the penis. We aimed to evaluate penile blood flow in vivo and analyze its possible relationship with the lymphatic maker. Materials and Methods: We established an in vivo system designed to assess the dynamic blood outflow from the corpus cavernosum (CC) by dye injection. To analyze lymphatic characteristics in the CC, the expression of Lyve-1, the key lymphatic endothelium marker, was examined by the in vitro system and lipopolysaccharide (LPS) injection to mimic the inflammatory conditions. Results: A novel cavernography methods enable high-resolution morphological and functional blood drainage analysis. The expression of Lyve-1 was detected along the sinusoids. Furthermore, its prominent expression was also observed after penile LPS injection and in the erectile condition. Conclusions: The current in vivo system will potentially contribute to the assessment of penile pathology from a novel viewpoint. In addition, current analyses revealed inducible Lyve-1 expression for LPS injection and the erection state, which requires further analyses on penile lymphatic system.

NLRP3 activation contributes to endothelin-1-induced erectile dysfunction.

In the present study, we hypothesized that endothelin (ET) receptors (ETA and ETB ) stimulation, through increased calcium and ROS formation, leads to Nucleotide Oligomerization Domain-Like Receptor Family, Pyrin Domain Containing 3 (NLRP3) activation. Intracavernosal pressure (ICP/MAP) was measured in C57BL/6 (WT) mice. Functional and immunoblotting assays were performed in corpora cavernosa (CC) strips from WT, NLRP3-/- and caspase-/- mice in the presence of ET-1 (100 nM) and vehicle, MCC950, tiron, BAPTA AM, BQ123, or BQ788. ET-1 reduced the ICP/MAP in WT mice, and MCC950 prevented the ET-1 effect. ET-1 decreased CC ACh-, sodium nitroprusside (SNP)-induced relaxation, and increased caspase-1 expression. BQ123 an ETA receptor antagonist reversed the effect. The ETB receptor antagonist BQ788 also reversed ET-1 inhibition of ACh and SNP relaxation. Additionally, tiron, BAPTA AM, and NLRP3 genetic deletion prevented the ET-1-induced loss of ACh and SNP relaxation. Moreover, BQ123 diminished CC caspase-1 expression, while BQ788 increased caspase-1 and IL-1ß levels in a concentration-dependent manner (100 nM-10 µM). Furthermore, tiron and BAPTA AM prevented ET-1-induced increase in caspase-1. In addition, BAPTA AM blocked ET-1-induced ROS generation. In conclusion, ET-1-induced erectile dysfunction depends on ETA - and ETB -mediated activation of NLRP3 in mouse CC via Ca2+ -dependent ROS generation.

The Acute Effects and Mechanism of Ketamine on Nicotine-Induced Neurogenic Relaxation of the Corpus Cavernosum in Mice.

The present study aimed to investigate the acute effects and the mechanism of ketamine on nicotine-induced relaxation of the corpus cavernosum (CC) in mice. This study measured the intra-cavernosal pressure (ICP) of male C57BL/6 mice and the CC muscle activities using an organ bath wire myograph. Various drugs were used to investigate the mechanism of ketamine on nicotine-induced relaxation. Direct ketamine injection into the major pelvic ganglion (MPG) inhibited MPG-induced increases in ICP. D-serine/L-glutamate-induced relaxation of the CC was inhibited by MK-801 (N-methyl-D-aspartate (NMDA) receptor inhibitor), and nicotine-induced relaxation was enhanced by D-serine/L-glutamate. NMDA had no effect on CC relaxation. Nicotine-induced relaxation of the CC was suppressed by mecamylamine (a non-selective nicotinic acetylcholine receptor antagonist), lidocaine, guanethidine (an adrenergic neuronal blocker), Nw-nitro-L-arginine (a non-selective nitric oxide synthase inhibitor), MK-801, and ketamine. This relaxation was almost completely inhibited in CC strips pretreated with 6-hydroxydopamine (a neurotoxic synthetic organic compound). Ketamine inhibited cavernosal nerve neurotransmission via direct action on the ganglion and impaired nicotine-induced CC relaxation. The relaxation of the CC was dependent on the interaction of the sympathetic and parasympathetic nerves, which may be mediated by the NMDA receptor.

Emerging structural and pathological analyses on the erectile organ, corpus cavernous containing sinusoids.

Background: The corpus cavernosum (CC) containing sinusoids plays fundamental roles for erection. Analysis of pathological changes in the erectile system is studied by recent experimental systems. Various in vitro models utilizing genital mesenchymal-derived cells and explant culture systems are summarized. Methods: 3D reconstruction of section images of murine CC was created. Ectopic chondrogenesis in aged mouse CC was shown by a gene expression study revealing the prominent expression of Sox9. Various experimental strategies utilizing mesenchyme-derived primary cells and tissue explants are introduced. Main Findings: Possible roles of Sox9 in chondrogenesis and its regulation by several signals are suggested. The unique character of genital mesenchyme is shown by various analyses of external genitalia (ExG) derived cells and explant cultures. Such strategies are also applied to the analysis of erectile contraction/relaxation responses to many signals and aging process. Conclusion: Erectile dysfunction (ED) is one of the essential topics for the modern aged society. More comprehensive studies are necessary to reveal the nature of the erectile system by combining multiple cell culture strategies.

STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses.

BACKGROUND: Stromal interaction molecule (STIM)/Orai calcium entry system appears to have a role in erectile dysfunction (ED) pathophysiology but its specific contribution to diabetic ED was not elucidated. AIM: To evaluate STIM/Orai inhibition on functional alterations associated with diabetic ED in rat and human penile tissues and on in vivo erectile responses in diabetic rats. METHODS: Rat corpus cavernosum (RCC) strips from nondiabetic (No DM) and streptozotocin-induced diabetic (DM) rats and human penile resistance arteries (HPRA) and corpus cavernosum (HCC) from ED patients undergoing penile prosthesis insertion were functionally evaluated in organ chambers and wire myographs. Erectile function in vivo in rats was assessed by intracavernosal pressure (ICP) responses to cavernous nerve electrical stimulation (CNES). Expression of STIM/Orai elements in HCC was determined by immunofluorescence and immunoblot. MAIN OUTCOME MEASURES: Functional responses in RCC, HCC and HPRA and STIM/Orai protein expression in HCC. In vivo erectile responses to CNES. RESULTS: Inhibition of Orai channels with YM-58483 (20 µM) significantly reduced adrenergic contractions in RCC but more effectively in DM. Thromboxane-induced and neurogenic contractions were reduced by STIM/Orai inhibition while defective endothelial, neurogenic and PDE5 inhibitor-induced relaxations were enhanced by YM-58483 (10 µM) in RCC from DM rats. In vivo, YM-58483 caused erections and attenuated diabetes-related impairment of erectile responses. YM-58483 potentiated the effects of PDE5 inhibition. In human tissues, STIM/Orai inhibition depressed adrenergic and thromboxane-induced contractions in ED patients more effectively in those with type 2 diabetes. Diabetes was associated with increased expression of Orai1 and Orai3 in ED patients. CLINICAL TRANSLATION: Targeting STIM/Orai to alleviate diabetes-related functional alterations of penile vascular tissue could improve erectile function and potentiate therapeutic effects of PDE5 inhibitors in diabetic ED. STRENGTHS AND LIMITATIONS: Improving effects of STIM/Orai inhibition on diabetes-related functional impairment was evidenced in vitro and in vivo in an animal model and validated in human tissues from ED patients. Functional findings were complemented with expression results. Main limitation was low numbers of human experiments due to limited human tissue availability. CONCLUSIONS: STIM/Orai inhibition alleviated alterations of functional responses in vitro and improved erectile responses in vivo in diabetic rats, potentiating the effects of PDE5 inhibition. STIM/Orai inhibition was validated as a target to modulate functional alterations of human penile vascular tissue in diabetic ED where Orai1 and Orai3 channels were upregulated. STIM/Orai inhibition could be a potential therapeutic strategy to overcome poor response to conventional ED therapy in diabetic patients. Sevilleja-Ortiz A, El Assar M, García-Gómez B, et al. STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses. J Sex Med 2022;19:1733-1749.

Histologic and physiologic analysis of the relationship between the dorsal nerve of the penis and the corpus cavernosum on a rat model. A complementary pathway on the innervation of penile erection?

AIM: The dorsal nerve of the penis (DNP) is the terminal branch of the pudendal nerve which is responsible for the somatic innervation of the penis. This study aims to outline any direct role of the DNP in the hemodynamics of erection histologically and physiologically. MATERIALS AND METHODS: Fifteen Wistar albino rats were sorted into the electrical activity (n = 6), intracavernous pressure (n = 4), and control (n = 5) groups. The dorsal nerve was electrostimulated and the simultaneous changes in intracavernous pressure and smooth muscle activity were recorded. Penile tissues were collected, fixed, and sectioned, the slides were stained with either hematoxylin-eosin for morphological evaluation or using the indirect immunoperoxidase technique to analyze the distributions of eNOS, iNOS, and nNOS. RESULTS: During electrostimulation, there was a simultaneous statistically significant decrease in the electrical activity inside the corpora in electromyography and an increase in intracavernous pressure. eNOS and iNOS immunoreactivities were higher in the study group than in the control group. nNOS immunoreactivity was moderate in both study and control groups. CONCLUSION: Some fibers in the dorsal nerve of penis continue into the corpora cavernosa through the tunica albuginea and have an active, direct role in the hemodynamic process of erection, which may be complementary to the main route of innervation.

Relaxation mechanisms of chloroform root extracts of Prangos heyniae and Prangos uechtritzii on mouse corpus cavernosum.

Erectile dysfunction (ED) is the inability to achieve/maintain an erection. Because of the side effects, interactions, or ineffectiveness of currently used drugs, novel drug discovery studies are ongoing. The roots of Turkish endemic plants Prangos uechtritzii and Prangos heyniae are traditionally used as aphrodisiacs in Anatolia and contain coumarin-like relaxant compounds. This study aims to reveal the relaxant effect mechanisms of chloroform root extracts of P. heyniae (Ph-CE) and P. uechtritzii (Pu-CE). Isolated organ bath experiments were performed on Swiss albino mouse corpus cavernosum by DMT strip myograph. Relaxant responses to extract (10-7 -10-4  g/ml) were obtained in the presence/absence of NO and H2 S synthesis inhibitors nitro-l-arginine methyl ester (l-NAME, 100 µM) and aminooxyacetic acid (AOAA, 10 mM) respectively. Sodium nitroprusside (SNP, 10-9 to 10-4  M) and Na2 S (10-6 to 3 × 10-3  M)-induced relaxations and CaCl2 (10-6 to 10-4  M), KCl (10-2.1 to 10-0.9  M) and phenylephrine (3 × 10-8 to 3 × 10-5  M)-induced contractions were taken in the presence/absence of the extracts (10-4  g/ml). Relaxations induced by Ph-CE but not by Pu-CE were inhibited in the presence of l-NAME and AOAA. Ph-CE increased Na2 S- and SNP-induced relaxations. Ph-CE and Pu-CE decreased the contractions of KCl, phenylephrine, and CaCl2 . It was concluded that NO and H2 S synthesis/downstream mechanisms play roles in relaxations of Ph-CE but not in Pu-CE-induced relaxations. Inhibition of calcium influx appears to be involved in the relaxant effect of Ph-CE and Pu-CE. Since the extracts act directly by relaxing smooth muscle or through H2 S as well as NO, they may be a potential therapeutic agent in diseases such as ED where the bioavailability of NO is impaired.

Establishment of mouse line showing inducible priapism-like phenotypes.

Purpose: Penile research is expected to reveal new targets for treatment and prevention of the complex mechanisms of its disorder including erectile dysfunction (ED). Thus, analyses of the molecular processes of penile ED and continuous erection as priapism are essential issues of reproductive medicine. Methods: By performing mouse N-ethyl-N-nitrosourea mutagenesis and exome sequencing, we established a novel mouse line displaying protruded genitalia phenotype (PGP; priapism-like phenotype) and identified a novel Pitpna gene mutation for PGP. Extensive histological analyses on the Pitpna mutant and intracavernous pressure measurement (ICP) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS)/MS analyses were performed. Results: We evaluated the role of phospholipids during erection for the first time and showed the mutants of inducible phenotypes of priapism. Moreover, quantitative analysis using LC-ESI/MS/MS revealed that the level of phosphatidylinositol (PI) was significantly lower in the mutant penile samples. These results imply that PI may contribute to penile erection by PITPα. Conclusions: Our findings suggest that the current mutant is a mouse model for priapism and abnormalities in PI signaling pathways through PITPα may lead to priapism providing an attractive novel therapeutic target in its treatment.

[Application value of color Doppler ultrasonography in the diagnosis of ruptured tunica albuginea of the corpus cavernosum penis].

OBJECTIVE: To assess the accuracy and value of ultrasonography in the diagnosis of ruptured tunica albuginea (RTA) of the corpus cavernosum penis. Factors affecting prognosis were analyzed. METHODS: This retrospective study included 57 cases of RTA of the corpus cavernosum penis ultrasonographically diagnosed and surgically treated in Peking University First Hospital from 2013 to 2021. We analyzed the location, size and number of ruptures and the presence or absence of urethral injury, and compared the intraoperative with the ultrasonographic findings. RESULTS: Of the 57 cases of RTA of the corpus cavernosum penis diagnosed by ultrasonography, 54 (94.7%) were confirmed by surgery. Preoperative ultrasonography indicated 2 cases of bilateral RTA and 6 cases of urethral injury, while surgery revealed 7 cases of bilateral RTA and 13 cases of combined urethral injury. Those with urethral injury developed no urethral stricture or urinary fistula after one-stage urethral repair. And no severe or moderate ED was found in any of the patients during the 12-month follow-up. CONCLUSION: Ultrasonography has a high accuracy in the diagnosis of ruptured tunica albuginea of the corpus cavernosum penis, and contributes to the determination of the site of surgical incision.

[Salidroside regulates the phenotypic transformation of corpus cavernosum smooth muscle cells of rats through the PDGFR/STAT3 signaling pathway].

OBJECTIVE: To explore the mechanism of Salidroside regulating the phenotypic transformation of cavernous smooth muscle cells (CCSMCs) in rats. METHODS: Primary CCSMCs were isolated from male SD rats, cultured in hypoxic environment for 24 hours, and treated with Salidroside at 30 µg/mL. Then the expressions of HIF-1α, platelet-derived growth factor receptor (PDGFR) and phenotypic transformation-related proteins α-SMA and Collagen I were detected by Western blot. The culture system of the CCSMCs was treated with exogenous PDGF-BB at 20 ng/mL for 24 hours, and the effects of Salidroside or PDGFR inhibitor Crenolanib (100 nmol/L) were observed. The expressions of PDGFR, phosphorylated PDGFR, phenotypic transformation-related proteins α-SMA and Collagen I, STAT3, phosphorylated STAT3, STAT5 and phosphorylated STAT5 were determined by Western blot. The intervention effects of Salidroside and/or the overexpression of STAT3 were observed after stimulation of the CCSMCs by exogenous PDGF-BB, followed by detection of the expressions of phenotypic transformation-related proteins α-SMA and Collagen I, STAT3 and phosphorylated STAT3 proteins. RESULTS: The expression of HIF-1α in the CCSMCs was significantly upregulated after cultured in hypoxic environment for 24 hours (P < 0.05), suggesting the successful construction of the hypoxia model of CCSMCs. Meanwhile, the expressions of PDGFRα, PDGFRß and Collagen I were remarkably increased (all P < 0.05), and that of α-SMA markedly decreased (P < 0.05) in the CCSMCs. However, the expressions of the all the proteins above were significantly inhibited by Salidroside intervention (all P < 0.05). After stimulated by exogenous PDGF-BB for 24 hours, the phosphorylation ratios of PDGFRα, PDGFRß and STAT3 and the expression of Collagen I were significantly elevated (all P < 0.05), that of α-SMA remarkably reduced (P < 0.05), and all were inhibited by intervention with crenolanib or Salidroside (all P < 0.05). No statistically significant difference was observed in the STAT5 phosphorylation ratio between different groups (P > 0.05). Overexpression of STAT3 in the CCSMCs treated with exogenous PDGF-BB and Salidroside significantly decreased the expression of α-SMA (P < 0.05) and increased that of Collagen I (P < 0.05). CONCLUSION: Salidroside could improve the phenotypic transformation of CCSMCs in male rats through the PDGFR/STAT3 signaling pathway, which needs further exploration and verification.

Dynamic erectile responses of a novel penile organ model utilizing TPEM†.

Male penis is required to become erect during copulation. In the upper (dorsal) part of penis, the erectile tissue termed corpus cavernosum (CC) plays fundamental roles for erection by regulating the inner blood flow. When blood flows into the CC, the microvascular complex termed sinusoidal space is reported to expand during erection. A novel in vitro explant system to analyze the dynamic erectile responses during contraction/relaxation is established. The current data show regulatory contraction/relaxation processes induced by phenylephrine (PE) and nitric oxide (NO) donor mimicking dynamic erectile responses by in vitro CC explants. Two-photon excitation microscopy (TPEM) observation shows the synchronous movement of sinusoidal space and the entire CC. By taking advantages of the CC explant system, tadalafil (Cialis) was shown to increase sinusoidal relaxation. Histopathological changes have been generally reported associating with erection in several pathological conditions. Various stressed statuses have been suggested to occur in the erectile responses by previous studies. The current CC explant model enables to analyze such conditions through directly manipulating CC in the repeated contraction/relaxation processes. Expression of oxidative stress marker and contraction-related genes, Hypoxia-inducible factor 1-alpha (Hif1a), glutathione peroxidase 1 (Gpx1), Ras homolog family member A (RhoA), and Rho-associated protein kinase (Rock), was significantly increased in such repeated contraction/relaxation. Altogether, it is suggested that the system is valuable for analyzing structural changes and physiological responses to several regulators in the field of penile medicine.

Mesenchymal stem cells-derived exosomal microRNA-21-5p downregulates PDCD4 and ameliorates erectile dysfunction in a rat model of diabetes mellitus.

Erectile dysfunction (ED) is a common comorbidity in males with diabetes mellitus (DM), whose pathogenesis might be induced by dysregulation of corpus cavernosum smooth muscle cells (CCSMCs). Gene Expression Omnibus repository-based analysis identified the differentially expressed PDCD4 in DM rats. PDCD4 has also been determined as a putative gene under the regulatory control of microRNA-21-5p (miR-21-5p). This study aimed to further determine the functional role of miR-21-5p in CCSMCs in a rat model of diabetes mellitus-induced erectile dysfunction (DMED). CCSMCs were isolated from penile cavernous tissue and cultured in high glucose (HG) medium. The expression of miR-21-5p and/or PDCD4 was altered in CCSMCs, as directly or indirectly measured by CCK-8 assay, flow cytometry, and TUNEL assays. Furthermore, exosomes were isolated from mesenchymal stem cells (MSCs) transfected with miR-21-5p mimic or miR-21-5p inhibitor and co-cultured with CCSMCs. DMED rats were injected with lentivirus carrying PDCD4/siRNA-PDCD4 plasmids, or exosomes from MSCs containing miR-21-5p-agomir to explore their roles in vivo. The experimental data validated that PDCD4 was upregulated in cavernous tissue of DMED rats. miR-21-5p targeted and inhibited PDCD4. miR-21-5p was enriched in MSC-exosomes. Moreover, PDCD4 downregulation, miR-21-5p elevation or MSC-derived exosomal miR-21-5p reduced apoptosis and enhanced proliferation of CCSMCs cultured in HG medium. PDCD4 silencing or miR-21-5p-containing MSC-exosomes improved erectile function and smooth muscle density in DMED rats. Collectively, our findings suggested that MSC-derived exosomal miR-21-5p suppressed PDCD4 expression and ED in rats with DM.

Infiltration of inflammatory factors induced penile damage in chronic prostatitis.

The present study aimed to investigate the mechanism of penile damages in experimental autoimmune prostatitis (EAP) rat models to reveal the potential pathological mechanism of the relationship between CP and penile damages. Sprague-Dawley (SD) rats were administered with different concentrations of prostate tissue homogenate supernatant (PTHS) by multipoint subcutaneous injection to establish EAP models. IHC staining was done to assess the expression of inflammatory cytokines in prostate tissues and the corpus cavernosum of penis. Masson and Tunel staining was conducted to observe the fibrosis and apoptosis in the corpus cavernosum. Finally, the functional changes of corpus cavernosum were assessed by WB and IHC staining. The results revealed that EAP rats with different prostatitis severity were successfully established by PTHS. The expression of IL-1ß, IL-6 and TNF-α in prostate tissues increased with the concentration of PTHS. The results of Masson and Tunel staining indicated fibrosis and apoptosis gradually aggravated in corpus cavernosum among different subgroups. The function of cavernosum impaired by prostatitis from WB and IHC results and positively with the severity. In conclusion, there existed the infiltration of inflammatory factors and impaired function in the corpus cavernosum of EAP rats' penis and positively correlated with the severity of prostatitis.

Role of shear wave elastography measured in the flaccid state in predicting arteriogenic erectile dysfunction.

The gold-standard method for diagnosing arteriogenic erectile dysfunction (AED) is the penile Doppler ultrasonography. We proposed a novel method for predicting AED using ultrasonic shear wave elastography (SWE) considering that the former was invasive and variable. A total of 98 male patients were enrolled in our study, referred for ED between December 2018 and October 2020. For comparison, we also included 42 volunteers from the Healthy Physical Examination Center of our hospital. The Penile Doppler Ultrasonography (PDU) and SWE were performed for all patients with the intracavernosal injection (ICI). We named three groups as AED group, nonvascular ED group and healthy controls group. No statistically significant differences were found among the three groups in terms of demographic and clinical characteristics. There were no significant differences in IIEF-5 between AED and nonvascular ED. A significant (r = 0.642, p < 0.0001) positive correlation between flaccid and erectile SWE was observed. With a cut-off value of 13.45 KPa, the area under curve, specificity, and sensitivity of the SWE values under the flaccid state in distinguishing AED from healthy subjects were 0.867, 0.786 and 0.896 respectively. The SWE value in the flaccid state can distinguish the AED from healthy subjects.

Fibrosarcoma of the corpus cavernosum: case report and literature review.

BACKGROUND: Fibrosarcoma is a very rare tumor that arises from fibrous tissue. Less than 5% of fibrosarcoma originate from the urogenital tract. Penile fibrosarcoma, even more rare, is characterized by pain, enlargement, penile erection and urinary tract obstruction. To our knowledge, this is the second reported case named "fibrosarcoma of the corpus cavernosum". CASE PRESENTATION: A 51-year-old male presented with a 1-month history of penis pain during erection. CT scan showed a soft tissue mass arising from the proximal part of the penis. We diagnosed it as penile sarcoma, performing local excision. The postoperative pathological result was moderately differentiated fibrosarcoma. 3 months later, CT scan showed the recurrence of the tumor, and multiple metastases. Although he received chemotherapy, he died 10 months after surgery. CONCLUSIONS: Fibrosarcoma of the corpus cavernosum is rare and have poor prognosis. Total penile amputation may be the best treatment. The effects of chemotherapy are limited. No more effective treatment has been found for a disseminated disease to date.

3D reconstruction and histopathological analyses on murine corporal body.

PURPOSE: Erectile dysfunction (ED) is one of the increasing diseases with aging society. The basis of ED derived from local penile abnormality is poorly understood because of the complex three-dimensional (3D) distribution of sinusoids in corpus cavernosum (CC). Understanding the 3D histological structure of penis is thus necessary. Analyses on the status of regulatory signals for such abnormality are also performed. METHODS: To analyze the 3D structure of sinusoid, 3D reconstruction from serial sections of murine CC were performed. Histological analyses between young (2 months old) and aged (14 months old) CC were performed. As for chondrogenic signaling status of aged CC, SOX9 and RBPJK staining was examined. RESULTS: Sinusoids prominently developed in the outer regions of CC adjacent to tunica albuginea. Aged CC samples contained ectopic chondrocytes in such regions. Associating with the appearance of chondrocytes, the expression of SOX9, chondrogenic regulator, was upregulated. The expression of RBPJK, one of the Notch signal regulators, was downregulated in the aged CC. CONCLUSIONS: Prominent sinusoids distribute in the outer region of CC which may possess important roles for erection. A possibility of ectopic chondrogenesis induced by alteration of SOX9/Notch signaling with aging is indicated.