Stem cell treatment may enhance erectile dysfunction (ED) in individuals with cavernous nerve injury (CNI). Nevertheless, no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on ED. We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED. Sprague-Dawley rats (total = 175) were randomly allocated into five groups. A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs (1 × 10 6 cells, 5 × 10 6 cells, and 1 × 10 7 cells in 0.1 ml, respectively). Penile tissues were harvested for histological analysis on 1 day, 3 days, 7 days, 14 days, 28 days, 60 days, and 90 days postsurgery. It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED. Moreover, there was no significant disparity in the effectiveness of various dosages of HUC-MSCs. However, the expression of endothelial markers (rat endothelial cell antigen-1 [RECA-1] and endothelial nitric oxide synthase [eNOS]), smooth muscle markers (alpha smooth muscle actin [α-SMA] and desmin), and neural markers (neurofilament [RECA-1] and neurogenic nitric oxide synthase [nNOS]) increased significantly with prolonged treatment time. Masson's staining demonstrated an increased in the smooth muscle cell (SMC)/collagen ratio. Significant changes were detected in the microstructures of various types of cells. In vivo imaging system (IVIS) analysis showed that at the 1 st day, the HUC-MSCs implanted moved to the site of damage. Additionally, the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
Male ; Animals ; Erectile Dysfunction/metabolism* ; Rats, Sprague-Dawley ; Mesenchymal Stem Cell Transplantation/methods* ; Rats ; Penis/pathology* ; Humans ; Disease Models, Animal ; Umbilical Cord/cytology* ; Peripheral Nerve Injuries/complications* ; Mesenchymal Stem Cells ; Nitric Oxide Synthase Type III/metabolism* ; Actins/metabolism* ; Nitric Oxide Synthase Type I/metabolism*

Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide. Radical prostatectomy (RP) is the standard treatment for localized prostate cancer, but the procedure often results in postoperative erectile dysfunction (ED). The poor efficacy of phosphodiesterase 5 inhibitors after surgery highlights the need to develop new therapies to enhance cavernous nerve regeneration and improve the erectile function of these patients. In the present study, we aimed to examine the potential of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in preserving erectile function in cavernous nerve injury (CNI) mice. We found that HB-EGF expression was reduced significantly on the 1 st day after CNI in penile tissue. Ex vivo and in vitro studies showed that HB-EGF promotes major pelvic ganglion neurite sprouting and neuro-2a (N2a) cell migration. In vivo studies showed that exogenous HB-EGF treatment significantly restored the erectile function of CNI mice to 86.9% of sham levels. Immunofluorescence staining showed that mural and neuronal cells were preserved by inducing cell proliferation and reducing apoptosis and reactive oxygen species production. Western blot analysis showed that HB-EGF upregulated protein kinase B and extracellular signal-regulated kinase activation and neurotrophic factor expression. Overall, HB-EGF is a major promising therapeutic agent for treating ED in postoperative RP.
Animals ; Male ; Heparin-binding EGF-like Growth Factor/therapeutic use* ; Erectile Dysfunction/etiology* ; Mice ; Penis/drug effects* ; Nerve Regeneration/drug effects* ; Penile Erection/drug effects* ; Peripheral Nerve Injuries/drug therapy* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Prostatectomy/adverse effects* ; Mice, Inbred C57BL ; Reactive Oxygen Species/metabolism*

Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits. The dorsal hippocampus (dHPC), a well-defined region responsible for learning and memory, displays maladaptive plasticity upon injury, which is assumed to underlie pain hypersensitivity and cognitive deficits. However, much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix (ECM) and decreases ECM rigidity in the dHPC. Despite this, it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits. Laminin, a key element of the ECM, consists of α-, β-, and γ-chains and has been implicated in several pathophysiological processes. Here, we showed that peripheral nerve injury downregulates laminin β1 (LAMB1) in the dHPC. Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction. Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrin β1, leading to decreased Ca²⁺ levels in pyramidal neurons, which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits. In this study, we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits, and reveal a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified hippocampal LAMB1/integrin β1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
Animals ; Laminin/genetics* ; Hippocampus/metabolism* ; Neuralgia/metabolism* ; Cognitive Dysfunction/etiology* ; Male ; Peripheral Nerve Injuries/metabolism* ; Extracellular Matrix/metabolism* ; Integrin beta1/metabolism* ; Pyramidal Cells/metabolism* ; Signal Transduction

Schwann cells and macrophages are the main immune cells involved in peripheral nerve injury. After injury, Schwann cells produce an inflammatory response and secrete various chemokines, inflammatory factors, and some other cytokines to promote the recruitment and M2 polarization of blood-derived macrophages, enhancing their phagocytotic ability, and thus play an important role in promoting nerve regeneration. Macrophages have also been found to promote vascular regeneration after injury, promote the migration and proliferation of Schwann cells along blood vessels, and facilitate myelination and axon regeneration. Therefore, there is a close interaction between Schwann cells and macrophages during peripheral nerve regeneration, but this has not been systematically summarized. In this review, the mechanisms of action of Schwann cells and macrophages in each other's migration and phenotypic transformation are reviewed from the perspective of each other, to provide directions for research on accelerating nerve injury repair.
Schwann Cells/metabolism* ; Peripheral Nerve Injuries/physiopathology* ; Animals ; Macrophages/immunology* ; Nerve Regeneration/physiology* ; Humans ; Cell Movement/physiology*

OBJECTIVE: It has been reported that local vibration therapy can benefit recovery after peripheral nerve injury, but the optimized parameters and effective mechanism were unclear. In the present study, we investigated the effect of local vibration therapy of different amplitudes on the recovery of nerve function in rats with sciatic nerve injury (SNI). METHODS: Adult male Sprague-Dawley rats were subjected to SNI and then randomly divided into 5 groups: sham group, SNI group, SNI + A-1 mm group, SNI + A-2 mm group, and SNI + A-4 mm group (A refers to the amplitude; n = 10 per group). Starting on the 7th day after model initiation, local vibration therapy was given for 21 consecutive days with a frequency of 10 Hz and an amplitude of 1, 2 or 4 mm for 5 min. The sciatic function index (SFI) was assessed before surgery and on the 7th, 14th, 21st and 28th days after surgery. Tissues were harvested on the 28th day after surgery for morphological, immunofluorescence and Western blot analysis. RESULTS: Compared with the SNI group, on the 28th day after surgery, the SFIs of the treatment groups were increased; the difference in the SNI + A-2 mm group was the most obvious (95% confidence interval [CI]: [5.86, 27.09], P < 0.001), and the cross-sectional areas of myocytes in all of the treatment groups were improved. The G-ratios in the SNI + A-1 mm group and SNI + A-2 mm group were reduced significantly (95% CI: [-0.12, -0.02], P = 0.007; 95% CI: [-0.15, -0.06], P < 0.001). In addition, the expressions of S100 and nerve growth factor proteins in the treatment groups were increased; the phosphorylation expressions of ERK1/2 protein in the SNI + A-2 mm group and SNI + A-4 mm group were upregulated (95% CI: [0.03, 0.96], P = 0.038; 95% CI: [0.01, 0.94], P = 0.047, respectively), and the phosphorylation expression of Akt in the SNI + A-1 mm group was upregulated (95% CI: [0.11, 2.07], P = 0.031). CONCLUSION Local vibration therapy, especially with medium amplitude, was able to promote the recovery of nerve function in rats with SNI; this result was linked to the proliferation of Schwann cells and the activation of the ERK1/2 and Akt signaling pathways.
Animals ; Male ; Peripheral Nerve Injuries/therapy* ; Proto-Oncogene Proteins c-akt/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/metabolism* ; Sciatic Neuropathy/metabolism* ; Vibration/therapeutic use*

Neuropathic pain is a chronic debilitating symptom characterized by spontaneous pain and mechanical allodynia. It occurs in distinct forms, including brush-evoked dynamic and filament-evoked punctate mechanical allodynia. Potassium channel 2.1 (Kir2.1), which exhibits strong inward rectification, is and regulates the activity of lamina I projection neurons. However, the relationship between Kir2.1 channels and mechanical allodynia is still unclear. In this study, we first found that pretreatment with ML133, a selective Kir2.1 inhibitor, by intrathecal administration, preferentially inhibited dynamic, but not punctate, allodynia in mice with spared nerve injury (SNI). Intrathecal injection of low doses of strychnine, a glycine receptor inhibitor, selectively induced dynamic, but not punctate allodynia, not only in naïve but also in ML133-pretreated mice. In contrast, bicuculline, a GABA receptor antagonist, induced only punctate, but not dynamic, allodynia. These results indicated the involvement of glycinergic transmission in the development of dynamic allodynia. We further found that SNI significantly suppressed the frequency, but not the amplitude, of the glycinergic spontaneous inhibitory postsynaptic currents (gly-sIPSCs) in neurons on the lamina II-III border of the spinal dorsal horn, and pretreatment with ML133 prevented the SNI-induced gly-sIPSC reduction. Furthermore, 5 days after SNI, ML133, either by intrathecal administration or acute bath perfusion, and strychnine sensitively reversed the SNI-induced dynamic, but not punctate, allodynia and the gly-sIPSC reduction in lamina IIi neurons, respectively. In conclusion, our results suggest that blockade of Kir2.1 channels in the spinal dorsal horn selectively inhibits dynamic, but not punctate, mechanical allodynia by enhancing glycinergic inhibitory transmission.
Animals ; Bicuculline ; pharmacology ; Disease Models, Animal ; Glycine ; metabolism ; Hyperalgesia ; drug therapy ; etiology ; metabolism ; Imidazoles ; pharmacology ; Inhibitory Postsynaptic Potentials ; drug effects ; physiology ; Male ; Mice, Inbred C57BL ; Neurons ; drug effects ; metabolism ; Neurotransmitter Agents ; pharmacology ; Peripheral Nerve Injuries ; drug therapy ; metabolism ; Phenanthrolines ; pharmacology ; Potassium Channels, Inwardly Rectifying ; antagonists & inhibitors ; metabolism ; Receptors, GABA-A ; metabolism ; Receptors, Glycine ; metabolism ; Strychnine ; pharmacology ; Synaptic Transmission ; drug effects ; physiology ; Tissue Culture Techniques ; Touch

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Jiaji" (EX-B 2) points combined with nerve mobilization on protein and mRNA expression of RhoA in rabbits with sciatic nerve injury, and to provide theoretical basis for the treatment of peripheral nerve injury by EA at "Jiaji" (EX-B 2) points combined with nerve mobilization. METHODS: A total of 180 New Zealand rabbits were randomly divided into a normal control group, a model control group, a nerve mobilization group, an EA group, an EA plus nerve mobilization group, 36 rabbits in each group. Each group was further divided into a 1-week subgroup, 2-week subgroup and 4-week subgroup, 12 rabbits in each subgroup. The sciatic nerve injury model was made by clamping method. The rabbits in the normal control group did not receive any intervention. The rabbits in the model control group was normally fed after operation. The rabbits in the nerve mobilization group were treated with nerve mobilization; the manipulation lasted for 1 s and relaxed for 5 s, 10 times per day, 6 days per week. The rabbits in the EA group were treated with EA at "Jiaji" (EX-B 2) points (L-L), once a day, 30 min each time, 6 times per week. The rabbits in the EA plus nerve mobilization group were treated with EA at "Jiaji" (EX-B 2) points, followed by nerve mobilization. The function of sciatic nerve on the injured side was evaluated by toe tension reflex and modified Tarlov score; the tissues of corresponding segments of spinal cord L-L and sciatic nerve were taken; the expression of RhoA gene was detected by real-time PCR and the expression of RhoA protein was detected by Western Blot. RESULTS: ① Toe tension reflex and modified Tarlov score: at 1, 2 and 4 weeks, the scores in the model control group were lower than those in the normal control group (all <0.01). The scores in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group were higher than those in the model control group (all <0.01), and the scores in the subgroup of EA plus nerve mobilization group were higher than those in the nerve mobilization group and the EA group (all <0.01); the recovery was the best at 4 weeks. ② The mRNA and protein expression of RhoA: in segment of spinal cord, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01), and the expression in the subgroup of EA plus nerve mobilization group was lower than that in the nerve mobilization group and the EA group (all <0.01); at 1 week and 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01). In the sciatic nerve, at 1, 2 and 4 weeks, the expression in the model control group was higher than that in the normal control group (all <0.01). The expression in the subgroup of nerve mobilization group, EA group and EA plus nerve mobilization group was lower than that in the model control group (all <0.01); at 2 weeks and 4 weeks, the expression in the EA plus nerve mobilization group was lower than that in the nerve mobilization group and EA group (all <0.01); at 1 week, the expression in the nerve mobilization group was lower than that in the EA group and EA plus nerve mobilization group (all <0.01), but the differences between the EA group and the EA plus nerve mobilization group were not significant (>0.05); at 2 weeks, the expression in the nerve mobilization group was higher than that in the EA group (all <0.01); at 4 weeks, the expression in the nerve mobilization group was lower than that in the EA group (all <0.01). CONCLUSION The nerve mobilization and EA at "Jiaji" (EX-B 2) points could both promote the repair of injured sciatic nerve, which may be related to the down-regulation of RhoA expression, and the combination of the two methods has better effects.
Acupuncture Points ; Animals ; Chlorophenols ; Electroacupuncture ; Peripheral Nerve Injuries ; RNA, Messenger ; metabolism ; Rabbits ; Sciatic Nerve ; injuries ; rhoA GTP-Binding Protein

We aimed to determine whether combination of LIM-kinase 2 inhibitor (LIMK2i) and phosphodiesterase type-5 inhibitor (PDE5i) could restore erectile function through suppressing cavernous fibrosis and improving cavernous apoptosis in a rat model of cavernous nerve crush injury (CNCI). Seventy 12-week-old Sprague-Dawley rats were equally distributed into five groups as follows: (1) sham surgery (Group S), (2) CNCI (Group I), (3) CNCI treated with daily intraperitoneal administration of 10.0 mg kg^-1 LIMK2i (Group I + L), (4) daily oral administration of 20.0 mg kg^-1 udenafil, PDE5i (Group I + U), and (5) combined administration of 10.0 mg kg^-1 LIMK2i and 20.0 mg kg^-1 udenafil (Group I + L + U). Rats in Groups I + L, I + U, and I + L + U were treated with respective regimens for 2 weeks after CNCI. At 2 weeks after surgery, erectile response was assessed using electrostimulation. Penile tissues were processed for histological studies and western blot. Group I showed lower intracavernous pressure (ICP)/mean arterial pressure (MAP), lower area under the curve (AUC)/MAP, decreased immunohistochemical staining for alpha-smooth muscle (SM) actin, higher apoptotic index, lower SM/collagen ratio, increased phospho-LIMK2-positive fibroblasts, decreased protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) phosphorylation, increased LIMK2/cofilin phosphorylation, and increased protein expression of fibronectin, compared to Group S. In all three treatment groups, erectile responses, protein expression of fibronectin, and SM/collagen ratio were improved. Group I + L + U showed greater improvement in erectile response than Group I + L. SM content and apoptotic index in Groups I + U and I + L + U were improved compared to those in Group I. However, Group I + L did not show a significant improvement in SM content or apoptotic index. The number of phospho-LIMK2-positive fibroblasts was normalized in Groups I + L and I + L + U, but not in Group I + U. Akt/eNOS phosphorylation was improved in Groups I + U and I + L + U, but not in Group I + L. LIMK2/cofilin phosphorylation was improved in Groups I + L and I + L + U, but not in Group I + U. Our data indicate that combined treatment of LIMK2i and PDE5i immediate after CN injury could improve erectile function by improving cavernous apoptosis or eNOS phosphorylation and suppressing cavernous fibrosis. Rectification of Akt/eNOS and LIMK2/cofilin pathways appears to be involved in their improvement.
Animals ; Apoptosis/drug effects* ; Arterial Pressure ; Electric Stimulation ; Erectile Dysfunction/pathology* ; Lim Kinases/antagonists & inhibitors* ; Male ; Nerve Crush ; Nitric Oxide Synthase Type III/metabolism* ; Penis/pathology* ; Peripheral Nerve Injuries/pathology* ; Phosphodiesterase 5 Inhibitors/therapeutic use* ; Phosphorylation ; Pyrimidines/therapeutic use* ; Rats ; Rats, Sprague-Dawley ; Sulfonamides/therapeutic use*

Injury to peripheral nerves can lead to neuropathic pain, along with well-studied effects on sensory neurons, including hyperexcitability, abnormal spontaneous activity, and neuroinflammation in the sensory ganglia. Neuropathic pain can be enhanced by sympathetic activity. Peripheral nerve injury may also damage sympathetic axons or expose them to an inflammatory environment. In this study, we examined the lumbar sympathetic ganglion responses to two rat pain models: ligation of the L5 spinal nerve, and local inflammation of the L5 dorsal root ganglion (DRG), which does not involve axotomy. Both models resulted in neuroinflammatory changes in the sympathetic ganglia, as indicated by macrophage responses, satellite glia activation, and increased numbers of T cells, along with very modest increases in sympathetic neuron excitability (but not spontaneous activity) measured in ex vivo recordings. The spinal nerve ligation model generally caused larger responses than DRG inflammation. Plasticity of the sympathetic system should be recognized in studies of sympathetic effects on pain.
Action Potentials ; physiology ; Animals ; Disease Models, Animal ; Female ; Ganglia, Sympathetic ; pathology ; Glial Fibrillary Acidic Protein ; metabolism ; Hyperalgesia ; etiology ; Ligation ; adverse effects ; Macrophages ; pathology ; Male ; Neurogenic Inflammation ; etiology ; Pain ; etiology ; pathology ; Patch-Clamp Techniques ; Peripheral Nerve Injuries ; complications ; Rats ; Rats, Sprague-Dawley ; Receptors, Antigen, T-Cell, alpha-beta ; metabolism

The present study aimed to identify which mitogen-activated protein kinase (p38 or Jun amino-terminal kinase [JNK]) was involved in cavernosal apoptosis during the acute phase after cavernosal nerve crush injury (CNCI) in rats to ameliorate apoptosis of cavernosal tissue, such as smooth muscle (SM). A total of twenty 10-week-old male Sprague-Dawley rats were divided equally into two groups: sham surgery (S) and CNCI (I). The I group approximated the clinical situation of men undergoing radical prostatectomy using two 60-second compressions of both CNs with a microsurgical vascular clamp. At 2-week postinjury, erectile response was assessed using electrostimulation. Penile tissues were harvested for immunohistochemistry analysis of alpha-SM actin (α-SMA), western blot analysis, and double immunofluorescence analysis of α-SMA and phosphorylated p38 or JNK, as well as double immunofluorescent of TUNEL and phosphorylated p38 or JNK. At 2-week postinjury, the I group had a significantly lower intracavernous pressure (ICP)/mean arterial pressure (MAP) and a lower area under the curve (AUC)/MAP than the S group. The I group also exhibited decreased immunohistochemical staining of α-SMA, an increase in the number of SM cells positive for phosphorylated JNK, an increased number of apoptotic cells positive for phosphorylated JNK, and increased JNK phosphorylation compared with the S group. However, there was no significant difference in p38 phosphorylation expression or the number of SM cells positive for phosphorylated p38 between the two groups. In conclusion, our data suggest that JNK, not p38, is involved in cavernosal apoptosis during the acute phase after partial CN damage.
Animals ; Apoptosis ; Disease Models, Animal ; Electric Stimulation ; MAP Kinase Kinase 4/metabolism* ; Male ; Penile Erection ; Penis/pathology* ; Peripheral Nerve Injuries/pathology* ; Phosphorylation ; Prostatectomy ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases/metabolism*