Bilateral Cavernous Nerve Injury Research Articles

(285) Heme-Binding Protein 1 Delivered via Pericyte-Derived Extracellular Vesicles Improves Neurovascular Regeneration in a Mouse Model of Cavernous Nerve Injury

Abstract Introduction As a peripheral nerve injury disease, cavernous nerve injury (CNI) caused by prostate cancer surgery and other pelvic surgery causes organic damage to cavernous blood vessels and nerves, thereby significantly attenuating the response to phosphodiesterase-5 inhibitors. Objective Here, we investigated the role of heme-binding protein 1 (Hebp1) in erectile function using a mouse model of bilateral CNI, which is known to promote angiogenesis and improve erection in diabetic mice. Methods To investigate the efficacy and mechanism of Hebp1 in restoring erectile function in CNI-induced ED mice, we injected recombinant mouse Hebp1 protein into the penis of CNI-induced ED mice. Detailed mechanisms were assessed using Signaling Explorer Antibody Arrays on penile tissue from CNI-induced ED mice; MPG tissue and Schwann cells were cultured in the presence of 2.5 μg/ml LPS. Results We found a potent neurovascular regenerative effect of Hebp1 in CNI mice, demonstrating that exogenously delivered Hebp1 improved erectile function by promoting the survival of cavernous endothelial-mural cells and neurons. We further found that endogenous Hebp1 delivered by mouse cavernous pericyte (MCP)-derived extracellular vesicles promoted neurovascular regeneration in CNI mice. Moreover, Hebp1 achieved these effects by reducing vascular permeability through regulation of claudin family proteins. Conclusions Our findings provide new insights into Hebp1 as a neurovascular regeneration factor and demonstrate its potential therapeutic application to various peripheral nerve injuries. Disclosure No.

Nrf2 enhances the therapeutic efficiency of adipose-derived stem cells in the treatment of neurogenic erectile dysfunction in a rat model

BackgroundErectile dysfunction (ED) caused by intraoperative nerve injury is a major complication of pelvic surgery. Adipose-derived stem cells (ADSCs) have presented therapeutic potential in a rat model of bilateral cavernous nerve injury (BCNI), while inadequate in vivo viability has largely limited their application. Nuclear factor-E2-related Factor (Nrf2) is a key transcription factor that regulates cellular anti-oxidative stress. In this work, we investigated the effect of Nrf2 expression regulation on the viability of ADSCs, and explore its repair potential in a BCNI rat model.ResultsThe survival time of tert-Butylhydroquinone (tBHQ)-ADSCs in BCNI model increased obviously. In addition, the tBHQ-ADSCs group presented better restoration of major pelvic ganglion (MPG) nerve contents and fibers, better improvement of erectile function, and less penile fibrosis than the other groups. Moreover, the expression of Nrf2 and superoxide dismutase 1 (SOD1) were higher than those of other groups.ConclusionNrf2 could enhance the anti-oxidative stress ability of ADSCs, so as to improve the therapeutic effect of ADSCs on BCNI rat model.

Biodegradable nano black phosphorus based SDF1-α delivery system ameliorates Erectile Dysfunction in a cavernous nerve injury rat model by recruiting endogenous stem/progenitor cells

Stem cell (SC) therapy has been shown high prospects in erectile dysfunction (ED) treatment. Without ethical issues and risks of immune rejection and tumorigenesis of exogenous SC therapy, endogenous stem/progenitor cells (S/PCs) have a better potential for ED management, and their homing and redistribution are controlled by SDF1-α/CXCR4 axis. Considering black phosphorus nanosheet (BPNS) has emerged as an efficient and safe drug vehicle due to its large surface area, biodegradability, and the ability to retain and slowly release its loaded drugs, BPNS is utilized to load SDF1-α, a chemokine for S/PCs, to construct the BP@SDF1-α complex to efficiently recruit stem cells (SCs) by injury-site injection and thus ameliorate ED within the bilateral cavernous nerve injury (BCNI) rat models. We find that BP@SDF1-α can efficiently recruit exogenous SCs and endogenous S/PCs to corpus cavernosum and main pelvic ganglion (MPG) by local administration. Of note, ascribing to endogenous S/PCs recruitment, it also successfully alleviates ED in BCNI rat models by enhancing the protein expression levels of α-SMA, CD31, and nNOs, and eliciting less collagen deposition in the penis after its combined injection at corpus cavernosum and MPG. Thus, this study provides a new insight into the treatment of ED with endogenous S/PCs.Biodegradable Nano Black Phosphorus based SDF1-α delivery system ameliorates Erectile Dysfunction in a cavernous nerve Injury Rat Model by recruiting endogenous Stem/Progenitor cells

Dimethyl fumarate ameliorates erectile dysfunction in bilateral cavernous nerve injury rats by inhibiting oxidative stress and NLRP3 inflammasome-mediated pyroptosis of nerve via activation of Nrf2/HO-1 signaling pathway

ObjectiveTo investigate the therapeutic potential of dimethyl fumarate (DMF) in improving erectile function of bilateral cavernous nerve injury (BCNI) rats, along with elucidating its underlying mechanisms. MethodsA BCNI rat model was established by clamping bilateral cavernous nerve (CN). DMF was given by gavage at low (20 mg/kg/day) and high (40 mg/kg/day) dosages for a duration of 4 weeks. Erectile function was assessed by electrical stimulation of CN. Penis and CN tissues were collected for subsequent analysis. Additionally, PC-12 cell line was used to verify the mechanism of DMF in vitro. Nfe2l2 or Ho-1 gene knockdown PC-12 cell lines were constructed by lentiviral transfection, respectively. A damaged cell model was induced using H2O2. And then molecular biological methods were employed to analyze cellular molecules and proteins. ResultsDMF administration for 4 weeks led to improvements in erectile function, reduced fibrosis of penis corpus cavernosum in BCNI rats. The morphology of CN was improved and the number of nerve fibers increased. Furthermore, the levels of nNOS, NO, and cGMP were increased, while Ca2+ was decreased in penis corpus cavernosum. Notably, the levels of ROS, 3-NT and NLRP3 inflammasomes production were reduced, alongside increased expression of Nrf2 and HO-1 proteins in the dorsal penile nerve (DPN) and CN. In vitro, DMF increased cell viability, reduced ROS level, promoted SOD, diminished 3-NT, MDA and DNA damage markers, and inhibited the activation of NLRP3 inflammasomes in H2O2 induced PC-12 cells. Nfe2l2 knockdown and Ho-1 knockdown significantly attenuated the protective effect of DMF, respectively. Furthermore, inhibition of ROS production by N-acetylcysteine led to a reduction in NLRP3 inflammasome activation in H2O2 induced PC-12 cells. ConclusionsDMF improved erectile function of BCNI rats by protecting nerves through inhibiting oxidative stress and the activation of NLRP3 inflammasome-mediated pyroptosis via activation of Nrf2/HO-1 pathway.

Caveolin-1 scaffolding domain peptide prevents corpus cavernosum fibrosis and erectile dysfunction in bilateral cavernous nerve injury-induced rats.

Corpus cavernosum (CC) fibrosis significantly contributes to post-radical prostatectomy erectile dysfunction (pRP-ED). Caveolin-1 scaffolding domain (CSD)-derived peptide has gained significant concern as a potent antagonist of tissue fibrosis. However, applying CSD peptide on bilateral cavernous nerve injury (BCNI)-induced rats remains uninvestigated. The aim was to explore the therapeutic outcome and underlying mechanism of CSD peptide for preventing ED in BCNI rats according to the hypothesis that CSD peptide may exert beneficial effects on erectile tissue and function following BCNI through limiting collagen synthesis in CC smooth muscle cells (CCSMCs) and CC fibrosis. After completing a random assignment of male Sprague Dawley rats (10 weeks of age), BCNI rats received either saline or CSD peptide treatment, as opposed to sham-operated rats. The evaluations of erectile function (EF) and succedent collection and histological and molecular biological examinations of penile tissue were accomplished 3weeks postoperatively. In addition, the fibrotic model of CCSMCs was used to further explore the mechanism of CSD peptide action in vitro. The assessments of EF, SMC/collagen ratio, α-smooth muscle actin, caveolin-1 (CAV1), and profibrotic indicators expressions were conducted. BCNI rats exhibited significant decreases in EF, SMC/collagen ratio, α-SMA, and CAV1 levels, and increases in collagen content together with transforming growth factor (TGF)-β1/Smad2 activity. However, impaired EF, activated CC fibrosis, and Smad2 signaling were attenuated after 3weeks of CSD peptide treatment in BCNI rats. In vitro, TGF-β1-induced CCSMCs underwent fibrogenetic transformation characterized by lower expression of CAV1, higher collagen composition, and phosphorylation of Smad2; then, the delivery of CSD peptide could significantly block CCSMC fibrosis by inactivating Smad2 signaling. Based on available evidence of CSD peptide in the prevention of ED in BCNI rats, this study can aid in the development and clinical application of CSD peptide targeting pRP-ED. This study provides data to suggest that CSD peptide protects against BCNI-induced deleterious alterations in EF and CC tissues. However, the available evidence still does not fully clarify the detailed mechanism of action of CSD peptide. Administration of CSD peptide significantly retarded collagen synthesis in CCSMCs, limited CC fibrosis, and prevented ED via confrontation of TGF-β1/Smad signaling in BCNI rats.

Effects of endoplasmic reticulum stress on erectile function in rats with cavernous nerve injury.

Erectile dysfunction (ED) occurs in an increasing number of patients after radical prostatectomy and cystectomy, and the phenotypic modulation of corpus cavernosum smooth muscle cells is closely related to ED. To determine whether endoplasmic reticulum stress (ERS) is implicated in the phenotypic modulation of ED induced by bilateral cavernous nerve injury (BCNI). In total, 36 Sprague-Dawley rats were randomly divided into 3 groups: sham, in which rats received sham surgery with bilateral cavernous nerve exposure plus phosphate-buffered saline; control, in which rats received BCNI plus phosphate-buffered saline; and experimental, in which rats received BCNI plus 4-phenylbutyric acid. Analysis of variance and a Bonferroni multiple-comparison test were utilized to evaluate differences among groups. Erectile function, smooth muscle/collagen ratios, and the expression levels of phenotypic modulation and ERS were measured. Two ratios-maximum intracavernosal pressure/mean arterial pressure and smooth muscle/collagen-were decreased in the control group as compared with the sham group. In penile tissue, there was increased expression of GRP78 (78-kDa glucose-regulated protein), p-PERK/PERK (phosphorylated protein kinase R-like endoplasmic reticulum kinase/protein kinase R-like endoplasmic reticulum kinase), caspase 3, CHOP (C/EBP homologous protein), and OPN (osteopontin) but decreased expression of nNOS (neuronal nitric oxide synthase) and α-SMA (α-smooth muscle actin). As compared with the control group, erectile function was improved and pathologic changes were partially recovered in the experimental group. The present study demonstrated that ERS is involved in ED caused by cavernous nerve injury, thereby providing a new target and theoretical basis for clinical treatment. The present study demonstrated for the first time that ERS is related to ED caused by cavernous nerve injury. Inhibition of ERS reverses phenotypic modulation and improves erectile function in rats with BCNI. Additional in vitro studies should be performed to verify these conclusions and explore the specific mechanism of phenotypic modulation. The present study demonstrated that inhibiting ERS reverses phenotypic modulation and enhances erectile function in rats with BCNI.

Ultrasound-targeted microbubble destruction mediates PDE5i/NO integration for cavernosum remodeling and penile rehabilitation.

Erectile dysfunction (ED) caused by cavernous nerve injury (CNI) is refractory to heal mainly ascribed to the adverse remodeling of the penis induced by ineffectual microvascular perfusion, fibrosis, and neurotrophins scarcity in cavernosum. Phosphodiesterase type V inhibitors (PDE5i) have been regarded as an alternative candidate drug for avoiding penile neuropathy. However, the therapeutic efficacy is severely limited due to poor accumulation under systemic medication and endogenous nitric oxide (NO) deficiency in cavernosum. Herein, an innovative liposomal microbubble (MB) loaded with both Sildenafil (one of PDE5i) and NO was designed. Ultrasound-targeted MB destruction (UTMD)-mediated efficient release and integration erectogenic agents into corpus cavernosum with high biosafety. On a bilateral CNI rat model, the multifunctional MB-cooperated UTMD improved microvascular perfusion in penis, simultaneously, alleviated hypoxia and oxidative stress, indicating successful activation of NO-cyclic guanosine monophosphate pathway. Also, evaluation of the endothelial/muscular composition, intracavernosal pressure, and neural integrity in the penis proved that coordinated intervention reversed the abnormal structural remodeling and promoted the recovery of functional erection. Our work demonstrates that MB loading Sildenafil and NO combined with UTMD hold great promise to "awaken" the efficacy of PDE5i in neurogenic ED, which provided a superior option for ensuring penile rehabilitation.

Erectile Dysfunction Treatment Using Stem Cell Delivery Patch in a Cavernous Nerve Injury Rat Model.

Erectile dysfunction (ED) is a common and feared complication of radical prostatectomy (RP) for prostate cancer. Recently, tissue engineering for post-prostatectomy ED has been attempted in which controlled interactions between cells, growth factors, and the extracellular matrix (ECM) are important for the structural integrity if nerve regeneration. In this study, we evaluated the effects of a biomechanical ECM patch on the morphology and behavior of human bone marrow-derived mesenchymal stem cells (hBMSCs) in a bilateral cavernous nerve injury (BCNI) rat model. The ECM patch, made of decellularized human fibroblast-derived ECM (hFDM) and a biocompatible polyvinyl alcohol (PVA) hydrogel, was tested with human bone marrow-derived mesenchymal stem cells (hBMSCs) on a bilateral cavernous nerve injury (BCNI) rat model. In vitro analysis showed that the hFDM/PVA + hBMSCs patches significantly increased neural development markers. In vivo experiments demonstrated that the rats treated with the hFDM/PVA patch had higher ICP/MAP ratios, higher ratios of smooth muscle to collagen, increased nNOS content, higher levels of eNOS protein expression, and higher cGMP levels compared to the BCNI group. These results indicate that the hFDM/PVA patch is effective in promoting angiogenesis, smooth muscle regeneration, and nitrergic nerve regeneration, which could contribute to improved erectile function in post-prostatectomy ED.

(229) Effect of Filtrated Bone Marrow-Derived Stem Cell Lysate on Erectile Function and Nerve Regeneration in Rats With Neurogenic Erectile Dysfunction

Abstract Introduction The transplantation of bone marrow-derived mesenchymal stem cell (BMSC) is believed to be a novel therapy for erectile dysfunction (ED) following radical prostatectomy (RP). However, the difficulty in preparation and higher costs challenge clinical application of this therapy. To overcome these challenges, we investigated the feasibility of filtrated BMSC lysate (BSCL) to alleviate ED in rats. We have reported BSCL improved erectile function in a rat model of bilateral cavernous nerve injury (BCNI). However, the mechanism remains unclear. Objective The study aimed to investigate the mechanism of BSCL for improving neurogenic ED focusing on nerve regeneration. Methods BSCL was obtained by freeze fracturing and filtrating BMSCs which were obtained from Wistar/ST rats. Three experiments were performed in this study. The first experiment included an eight-week-old male Wistar/ST rats, further divided into three groups: Sham + PBS, BCNI + PBS, and BCNI + BSCL (n=8). Rats in the Sham + PBS group underwent sham surgery, while those in the BCNI + PBS group underwent BCNI surgery. Immediately after the surgery, phosphate-buffered saline (PBS) was injected into the corpus cavernosum. Rats in the BCNI+BSCL group also underwent BCNI surgery. Immediately after the surgery, BSCL was injected into the corpus cavernosum. Four weeks after the surgery, erectile function was evaluated by measuring intracavernosal pressure (ICP)/mean arterial pressure (MAP) under stimulation of cavernous nerve. The second experiment was conducted on eight-week-old male Wistar/ST rats, further divided into three groups, same as in the first experiment. Three weeks after the surgery, fluorogold (FG) was injected into the corpus cavernosum from both sides. One week after the injection, bilateral major pelvic ganglions (MPGs) were dissected. FG reaching to MPG was observed using fluorescence microscope. The MPGs were also proved with anti PGP9.5, a neuron cell marker. In the third experiment, MPG were dissected from ten-week-old male Wistar/ST rats, placed on Matrigel and incubated with normal medium or medium including BSCL (50, 125, 250, and 500 ng/mL, respectively). After 48 hours, neurite outgrowth was measured using a Z-stack microscope. Results ICP/MAP in the BCNI+PBS group was significantly lower than that in the Sham+PBS group (P < 0.05), and ICP/MAP in the BCNI+BSCL group was significantly higher than that in the BCNI+PBS group (P < 0.05). The ratios of FG positive cells to PGP9.5 positive cells in the BCNI+PBS group were significantly lower than those in the Sham+PBS group. Those in the BCNI+BSCL group were higher than those in the BCNI+PBS group. MPG treated with the medium including BSCL had longer neurite outgrowth than MPG treated with normal medium. This neurite outgrowth effect of BSCL increased in a dose-dependent manner. Conclusions In conclusion, BSCL treatment improved erectile function in rats with neurogenic ED. In addition, BSCL has the potential to improve neurotransmission of cavernous nerves and BSCL exhibited neurite outgrowth effects on rat MPG. The study demonstrates that BSCL can regenerate a crushed cavernous nerve, improving erectile function. Further study should be conducted to identify active factors in BSCL contributing to nerve regeneration. Disclosure No

(093) The Light-Controlled Nitric Oxide Donor “NORD-1” may Improve Erectile Function Without Hypotension and Tissue Damage in Rats With Neurogenic Erectile Dysfunction

Abstract Introduction Radical prostatectomy (RP) often causes erectile dysfunction (ED) because of cavernous nerve damage during surgery. This damage results in a decrease of nitric oxide (NO) in the penile corpus cavernosum. Therefore, NO supplementation is considered to be effective for post RP ED. However, NO has systemic side effects such as headache and hypotension. Recently, a red-light-controlled NO donor “NORD-1”, developed by our group, enables spatially and temporally controlled NO release by light irradiation. Our previous study reported that NORD-1 combined with red-light irradiation is effective for neurogenic ED model rats with bilateral cavernous nerve injury (BCNI). However, the side effects of the treatment have not yet been discussed. Objective The study aimed to investigate the potency of side effects associated with the combination of NORD-1 and red-light irradiation, using a ED rat model with BCNI. Methods In this study, eight-week-old male Wistar-ST rats were used. The rats were divided into four groups: Sham+SiR650 (control compound), Sham+NORD-1, BCNI+SiR650, and BCNI+NORD-1 (n=6). The sham or BCNI surgery was performed under anesthesia in each group. BCNI surgery was performed by crushing the cavernous nerves bilaterally. Four weeks post-surgery, erectile function before and after the injection of each reagent into the penile corpus cavernosum was evaluated based on the changes in intracavernous pressure (ICP) under electrostimulation of the cavernous nerve. After the administration of each reagent, the changes in ICP with and without light irradiation were also evaluated. ICP during electrostimulation was totally measured three times; once without reagent and light, once with reagent and without light and once with reagent and light. The variations in systemic arterial pressure during electrostimulation were also analyzed. After the experiment, penile samples were collected to observe NORD-1 localization using a fluorescence microscope. In addition, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to evaluate apoptosis in the corpus cavernousm. Results Before administering each reagent without light irradiation, the ICP/mean arterial pressure (MAP) ratios under stimulation in the BCNI+SiR650 and BCNI+NORD-1 groups were significantly lower than those in the Sham+SiR650 (P < 0.01) and Sham+NORD-1 (P < 0.05) groups. After administering each reagent without light irradiation, the ICP/MAP ratios in the BCNI+SiR650 and BCNI+NORD-1 groups remained significantly lower than those in the Sham+SiR650 and Sham+NORD-1 group (P < 0.05 and P < 0.01, respectively). After administering each reagent with light irradiation, the ICP/MAP ratios in the Sham+NORD-1 and BCNI+NORD-1 groups were significantly higher than those in the Sham+SiR650 (P < 0.01) and BCNI+NORD-1 (P < 0.01) groups, respectively. The changes of MAP during electrostimulation were not different under three different conditions in all four groups. Fluorescence of NORD-1 was detected only in corpus cavernousum which means it was not detected in urethra and dorsal vein of penis. Apoptosis was not detected in corpus cavernousum in all four groups. Conclusions The combination of NORD-1 and light irradiation is effective for neurogenic ED in rats with cavernous nerve injury. The treatment may not cause hypotension and tissue damage. Disclosure No

Implantation of skin-derived precursor Schwann cells improves erectile function in a bilateral cavernous nerve injury rat model

BackgroundThis study was conducted to investigate the therapeutic potential of the skin-derived precursor Schwann cells for the treatment of erectile dysfunction in a rat model of bilateral cavernous nerve injury.ResultsThe skin-derived precursor Schwann cells-treatment significantly restored erectile functions, accelerated the recovery of endothelial and smooth muscle tissues in the penis, and promoted nerve repair. The expression of p-Smad2/3 decreased after the treatment, which indicated significantly reduced fibrosis in the corpus cavernosum.ConclusionsImplantation of skin-derived precursor Schwann cells is an effective therapeutic strategy for treating erectile dysfunction induced by bilateral cavernous nerve injury.

Role of mechanotransduction mediated by YAP/TAZ in the treatment of neurogenic erectile dysfunction with low-intensity pulsed ultrasound.

Erectile dysfunction (ED) and weakness of the penis are processes related to hemodynamic alteration. Low-intensity pulsed ultrasound (LIPUS), as a new mechanical modality for the treatment of ED, deserves to be explored in depth for the biomechanical mechanisms it exerts. The aim of this study was to explore the role of YAP/TAZ-mediated mechanotransduction in mechanical therapy for the treatment of neurogenic erectile dysfunction (NED). Forty-two male SD rats (12 w old) were randomly divided into sham-operated (n=14), bilateral cavernous nerve injury (BCNI, n=14), and LIPUS-treated (n=14) groups. Intracavernosal pressure/mean arterial pressure (ICP/MAP) was measured 14 and 28 days after treatment. Penile tissue specimens were collected for pathological examination, and the changes in YAP, TAZ, connective tissue growth factor (CTGF), CYR61, LATS1, and p38 mitogen-activated protein kinase expression levels were assessed by Western blot, real-time quantitative polymerase chain reaction (RT-qPCR) and immunological staining. Compared with BCNI, LIPUS significantly improved ICP/MAP levels and enhanced histopathological changes. The penile expression levels of YAP, TAZ, CTGF, and CYR61 were significantly downregulated in the BCNI group (p<0.01), and LIPUS upregulated the expression levels of these proteins (p<0.05). The expression levels of p-LATS1 and LATS1 were not significantly different among the groups (p>0.05). Interestingly, the expression level of p-p38/p38 significantly increased in BCNI rats (p<0.05), which was reversed by LIPUS treatment (p<0.05). However, the p38 inhibitor SB203580 did not change the expression of YAP/TAZ in rat primary smooth muscle cells or mouse MOVAS cells (p>0.05). LIPUS can effectively improve penile erectile function in NED rats. The underlying mechanism may be related to the regulation of YAP/TAZ-mediated mechanotransduction. However, the upstream regulatory signal may differ from the classical Hippo pathway.

Low-intensity pulsed ultrasound ameliorates erectile dysfunction induced by bilateral cavernous nerve injury through enhancing Schwann cell-mediated cavernous nerve regeneration.

Cavernous nerve injury-induced erectile dysfunction caused by pelvic surgery or trauma is refractory to conventional medications and required an alternative treatment. Low-intensity pulsed ultrasound is a noninvasive mechanical therapy that promotes nerve regeneration. To investigate the therapeutic effect and potential mechanism of low-intensity pulsed ultrasound in the treatment of neurogenic erectile dysfunction. Thirty rats were randomly divided into the sham-operated group, bilateral cavernous nerve injury group, and bilateral cavernous nerve injury + low-intensity pulsed ultrasound group. The erectile function was assessed 3weeks after daily low-intensity pulsed ultrasound treatment. The penile tissues and cavernous nerve tissues were harvested and subjected to histologic analysis. Primary Schwann cells and explants were extracted from adult rats. The effects of low-intensity pulsed ultrasound on proliferation, migration, and nerve growth factor expression of Schwann cells and axonal elongation were examined in vitro. RNA sequencing and western blot assay were applied to predict and verify the molecular mechanism of low-intensity pulsed ultrasound-induced Schwann cell activation. Our study showed that low-intensity pulsed ultrasound promoted Schwann cells proliferation, migration, and neurotrophic factor nerve growth factor expression. Meanwhile, low-intensity pulsed ultrasound exhibits a stronger ability to enhance Schwann cells-mediated neurite outgrowth of major pelvic ganglion neurons and major pelvic ganglion/cavernous nerve explants in vitro. In vivo experiments demonstrated that the erectile function of the rats in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group was significantly higher than those in the bilateral cavernous nerve injury groups. Moreover, the expression levels of smooth muscle and cavernous endothelium also increased significantly in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group. In addition, we observed the higher density and number of cavernous nerve regenerating axons in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group, indicating that low-intensity pulsed ultrasound promotes axonal regeneration following cavernous nerve injury in vivo. RNA sequencing analysis and bioinformatic analysis suggested that low-intensity pulsed ultrasound might trigger the activation of the PI3K/Akt pathway. Western blot assay confirmed that low-intensity pulsed ultrasound activated Schwann cells through TrkB/Akt/CREB signaling. Low-intensity pulsed ultrasound promoted nerve regeneration and ameliorated erectile function by enhancing Schwann cells proliferation, migration, and neurotrophic factor nerve growth factor expression. The TrkB/Akt/CREB axis is the possible mechanism of low-intensity pulsed ultrasound-mediated Schwann cell activation. Low-intensity pulsed ultrasound-based therapy could be a novel potential treatment strategy for cavernous nerve injury-induced neurogenic erectile dysfunction.

Riluzole, a neuroprotective agent, preserves erectile function following bilateral cavernous nerve injury in male rats.

Neurogenic erectile dysfunction is a highly prevalent complication in men undergoing radical prostatectomy. The underlying mechanisms remain incompletely defined and the effective therapy has been limited. This study aimed to evaluate the protective effect of riluzole and the role of PKC β and excitatory amino acid transporters (EAATs) mediating this effect in a rat model of bilateral cavernous injury (BCNI). A total of 48 male Sprague-Dawley rats were divided into sham, BCNI (at 7, 15 days post-injury) and BCNI treated with riluzole (8 mg/kg/day) groups. Erectile function was measured as maximum intracavernosal pressure (mICP)/mean arterial pressure (MAP) and total ICP/MAP. Changes in protein expressions of phospho (p)-PKC β IIser660 and EAATs were analysed in penis and major pelvic ganglion with western blotting. BCNI decreased erectile function at 7 and 15 days post-injury (mICP/MAP at 4 V: 0.45 ± 0.06 vs 0.84 ± 0.07; 0.34 ± 0.04 vs 0.77 ± 0.04 respectively; p < 0.001) whereas riluzole treatment (for 15 days) preserved erectile function (mICP/MAP at 4 V: 0.62 ± 0.03 vs 0.34 ± 0.04; p < 0.01). The decline in the expression of p-PKC β IIser660 was observed in penis at 7 and 15 days post-injury (p = 0.0003, p = 0.0033), which was prevented by riluzole treatment for 15 days (p = 0.0464). While expressions of EAAT-1 and EAAT-2 decreased in major pelvic ganglion following BCNI (p = 0.0428, p = 0.002), riluzole treatment for 15 days prevented the decrease only in EAAT-2 expression (p = 0.0456). Riluzole improved erectile function via possibly interacting with PKC β II and glutamatergic pathways, as a potential therapeutic candidate for erectile dysfunction.

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.

Efficacy of a Red-Light Controllable Nitric Oxide Releaser for Neurogenic Erectile Dysfunction: A Study Using a Rat Model of Cavernous Nerve Injury.

Neurogenic erectile dysfunction (ED) is a common side effect of radical prostatectomy (RP) because of cavernous nerve damage. In these patients, the production of nitric oxide (NO), which is important for erection, is decreased in the corpus cavernosum. Therefore, NO donors are useful for post-RP ED. However, short half-life and systemic side effects are problems of NO application in ED therapy. To avert these problems, we developed a red-light controllable NO releaser, NORD-1. This study aimed to investigate the effect of NORD-1 and red-light irradiation on neurogenic ED using a rat model of bilateral cavernous nerve injury (BCNI). BCNI and sham operations were conducted on 8-week-old rats. After 4 weeks, erectile function was evaluated using changes in intracavernous pressure (ICP) during electrostimulation of the cavernous nerve. ICP was measured under three conditions; without NORD-1 and red-light irradiation, with NORD-1 and without red-light irradiation, and with NORD-1 and red-light irradiation. SiR650 which absorbs red-light but does not release NO was used for the negative control. After the experiment, localization of NORD-1 was observed using a microscope. Erectile function in a BCNI rat model was significantly decreased compared to sham-operated rats (p<0.05). After injecting NORD-1 into the penis, erectile function did not change without red-light irradiation. However, the combination of NORD-1 and red-light irradiation significantly improved erectile function (p<0.05) without affecting systemic arterial pressure. In contrast, when SiR650 was used, erectile function did not change in all three conditions. NORD-1 was detected only in the corpus cavernosum and not in the urethra and dorsal vein. NORD-1 combined with red-light irradiation is effective for ED induced by cavernous nerve injury. This treatment may have low risks of hypotension and urinary incontinence, and it can replace the current treatment for post-RP ED.

Adipose Derived Mesenchymal Stem Cells-Derived Mitochondria Transplantation Ameliorated Erectile Dysfunction Induced by Cavernous Nerve Injury.

Erectile dysfunction (ED) is a common postoperative complication of pelvic surgery for which there is currently no effective treatment. This study investigated the therapeutic effects and potential mechanisms of adipose derived mesenchymal stem cells-derived mitochondria (ADSCs-mito) transplantation in a rat model of bilateral cavernous nerve injury (CNI) ED. We isolated mitochondria from ADSCs and tested their quality. In vivo, twenty male Sprague Dawley rats were randomly divided into four groups: sham operation group and CNI groups that received intracavernous injection of either phosphate buffer solution, ADSCs-mito or ADSCs. Two weeks after therapy, the erectile function of the rats was evaluated and the penile tissues were harvested for histologic analysis and western blotting. In vitro, the apoptosis rate, reactive oxygen species (ROS), mitochondria derived active oxygen (mtROS) and adenosine triphosphate (ATP) levels were detected in corpus cavernosum smooth muscle cells (CCSMCs) after the incubation with ADSCs-mito. In addition, intercellular mitochondrial transfer was visualized by co-culture of ADSCs and CCSMCs. The ADSCs, ADSCs-mito and CCSMCs were isolated and identified successfully. ADSCs-mito transplantation notably restored the erectile function and smooth muscle content of CNI ED rats. Moreover, the levels of ROS, mtROS and cleaved-caspase 3 were reduced and the levels of superoxide dismutase and ATP were increased after ADSCs-mito transplantation. In CNI ED rats, the mitochondrial structure of cells in penile tissues was destroyed. ADSCs could transfer its own mitochondria to CCSMCs. Pre-treatment with ADSCs-mito could significantly decrease apoptosis rate, ROS levels and mtROS levels as well as restore the ATP level in CCSMCs. ADSCs-mito transplantation significantly ameliorated ED induced by CNI, with similar potency to ADSCs treatment. The ADSCs-mito might exert their effects via anti-oxidative stress, anti-apoptosis and modulating energy metabolism of CCSMCs. Mitochondrial transplantation should be a promising therapeutic method for treating CNI ED in the future.

Heme-binding protein 1 delivered via pericyte-derived extracellular vesicles improves neurovascular regeneration in a mouse model of cavernous nerve injury.

As a peripheral nerve injury disease, cavernous nerve injury (CNI) caused by prostate cancer surgery and other pelvic surgery causes organic damage to cavernous blood vessels and nerves, thereby significantly attenuating the response to phosphodiesterase-5 inhibitors. Here, we investigated the role of heme-binding protein 1 (Hebp1) in erectile function using a mouse model of bilateral CNI, which is known to promote angiogenesis and improve erection in diabetic mice. We found a potent neurovascular regenerative effect of Hebp1 in CNI mice, demonstrating that exogenously delivered Hebp1 improved erectile function by promoting the survival of cavernous endothelial-mural cells and neurons. We further found that endogenous Hebp1 delivered by mouse cavernous pericyte (MCP)-derived extracellular vesicles promoted neurovascular regeneration in CNI mice. Moreover, Hebp1 achieved these effects by reducing vascular permeability through regulation of claudin family proteins. Our findings provide new insights into Hebp1 as a neurovascular regeneration factor and demonstrate its potential therapeutic application to various peripheral nerve injuries.

Improvement of erectile dysfunction using endothelial progenitor cells from fetal cerebral vasculature in the cavernous nerve injury of rats

BackgroundBecause of limited differentiation to endothelium from mesenchymal stem cells, it has been strongly recommended to use endothelial progenitor cells for the regeneration of the damaged endothelium of corpora cavernosa. This study was performed to investigate the immortalized human cerebral endothelial cells and their capability for repairing erectile dysfunction in a rat model of cavernous nerve injury. Circulating endothelial progenitor cells were isolated from human fetal brain vasculature at the periventricular region of telencephalic tissues. Over 95% of CD 31-positive cells were sorted and cultured for 10 days. Human cerebral endothelial progenitor cells were injected into the cavernosa of rats with cavernous nerve injury. Erectile response was then assessed. In in vivo assays, rats were divided into three groups: group 1, sham operation: group 2, bilateral cavernous nerve injury: and group 3, treatment with human cerebral endothelial cells after cavernous nerve injury.ResultsEstablished immortalized circulating endothelial progenitor cells showed expression of human telomerase reverse transcriptase transcript by RT-PCR. They also showed the expression of vascular endothelial growth factor, von Willebrand factor, vascular endothelial growth factor receptor, and CD31, cell type-specific markers for endothelial cells by RT-PCR. In in vitro angiogenesis assays, they demonstrated tube formation that suggested morphological properties of endothelial progenitor cells. In in vivo assays, impaired erectile function of rat with cavernous nerve injury recovered at 2, 4, and 12 weeks after transplantation of human cerebral endothelial cells into the cavernosa.ConclusionsTelomerase reverse transcriptase-circulating endothelial progenitor cells from fetal brain vasculature could repair erectile dysfunction of rats with cavernous nerve injury.

Injectable thermo-sensitive hydrogel containing ADSC-derived exosomes for the treatment of cavernous nerve injury

Radical pelvic surgery is commonly accompanied by the risk of postoperative erectile dysfunction induced by cavernous nerve injury (CNI-ED). The strategy of using adipose mesenchymal stem cell-derived exosomes (ADSC-Exo) to treat neurodegenerative diseases has shown promising results. However, it remains challenging to prolong the retention of unbound ADSC-Exo in damaged tissues to exert therapeutic effects. Herein, we develop a novel injectable thermo-sensitive hydroxyethyl chitosan/sodium β-glycerophosphate hydrogel (HG) encapsulating ADSC-Exo (HG@Exo) to manage CNI-ED. The HG exhibits excellent injectability, structural stability, and body temperature sensitivity. In vivo assessment demonstrates that the designed ADSC-Exo-loaded HG hydrogel enhances the retention of ADSC-Exo and displays a slow release. Furthermore, when HG@Exo is applied to the site of nerve injury, erectile function in the bilateral cavernous nerve injury rat model is significantly improved. Thus, our finding indicates that the developed bioactive hydrogel presents a promising strategy for the effective management of CNI-ED.