Pericyte-Derived Extracellular Vesicle-Mimetic Nanovesicles Restore Erectile Function by Enhancing Neurovascular Regeneration in a Mouse Model of Cavernous Nerve Injury

Photobiomodulation as a Potential Therapy for Erectile Function: A Preclinical Study in a Cavernous Nerve Injury Model

PURPOSE

To identify the optimal photobiomodulation (PBM) parameters using molecular, histological, and erectile function analysis in cavernous nerve injury.

MATERIALS AND METHODS

A cavernous nerve injury was induced in 8-week-old C57BL/6J male mice that were subsequently divided randomly into age-matched control groups. Erectile function tests, penile histology, and Western blotting were performed 2 weeks after surgery and PBM treatment.

RESULTS

The PBM treatment was administered for five consecutive days with a light-emitted diode (LED) device that delivers 660 nm±3% RED light, and near infra-red 830 nm±2% promptly administered following nerve-crushing surgery and achieved a notable restoration of erectile function approximately 90% of the control values. Subsequent in-vitro and ex-vivo analyses revealed the regeneration of neurovascular connections in both the dorsal root ganglion and major pelvic ganglion, characterized by the sprouting of neurites. Furthermore, the expression levels of neurotrophic, survival, and angiogenic factors exhibited a substantial increase across all groups subjected to PBM treatment.

CONCLUSIONS

The utilization of PBM employing LED with 660 nm, 830 nm, and combination of both these wavelengths, exhibited significant efficacy to restore erectile function in a murine model of cavernous nerve injury. Thus, the PBM emerges as a potent therapeutic modality with notable advantages such as efficacy, noninvasiveness, and non-pharmacological interventions for erectile dysfunction caused by nerve injury.

Dual Strategy with Adipose-Derived Stem Cells and l-arginine Recovered Cavernosal Functions in a Rat Model of Radical Prostatectomy

As standard therapy for prostate cancer, radical prostatectomy causes cavernous nerve (CN) injury and increases fibrosis and hypoxia-induced penile structural alterations. This study aimed to determine the potential beneficial effects of adipose-derived stem cells (ADSCs) and l-arginine alone or in combination on the penile erection in a rat model of erectile dysfunction caused by bilateral cavernous nerve transection (CNT). Male rats (n = 35) were randomized into five groups: Sham-operated; CNT (4-weeks); CNT plus ADSCs (1 × 106 cells by intracavernosal injection); CNT plus l-arginine (4 weeks, 10 mg/kg/day, oral); and ADSCs combined with l-arginine in CNT. In vivo erectile responses and in vitro relaxant responses were measured. Western blot and immunohistochemistry analyses were used to determine the expression and localization of endothelial nitric oxide synthase, neuronal nitric oxide synthase, transforming growth factor-beta 1, hypoxia-inducible factor-1 alpha (HIF-1α), and apoptosis markers (Bax and Bcl-2). The ratio of smooth muscle to collagen and nerve regeneration were calculated using Masson's trichrome and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining. The combined treatment restored diminished erectile responses, endothelium-dependent acetylcholine, and electrical field stimulation-induced relaxation of the corpus cavernosum in rats with CNT, whereas either monotherapy produced only partial improvements. All treatment regimens restored increases in the protein expression of HIF-1 and Bax in rats with CNT. The decrease in smooth muscle mass and NADPH-diaphorase-positive nerve fibers was partially ameliorated by monotherapy, whereas combined therapy led to recovery. These findings indicate that combined treatment with ADSCs and l-arginine may restore erectile function in rats with CNT by inhibiting hypoxia-induced neurotoxicity and preserving endothelium function and smooth muscle content.

MicroRNA-148a-3p in pericyte-derived extracellular vesicles improves erectile function in diabetic mice by promoting cavernous neurovascular regeneration

BACKGROUND

To investigate the regulatory role of microRNA (miR)-148a-3p in mouse corpus cavernous pericyte (MCPs)-derived extracellular vesicles (EVs) in the treatment of diabetes-induced erectile dysfunction (ED).

METHODS

Mouse corpus cavernous tissue was used for MCP primary culture and EV isolation. Small-RNA sequencing analysis was performed to assess the type and content of miRs in MCPs-EVs. Four groups of mice were used: control nondiabetic mice and streptozotocin-induced diabetic mice receiving two intracavernous injections (days - 3 and 0) of phosphate buffered saline, MCPs-EVs transfected with reagent control, or MCPs-EVs transfected with a miR-148a-3p inhibitor. miR-148a-3p function in MCPs-EVs was evaluated by tube-formation assay, migration assay, TUNEL assay, intracavernous pressure, immunofluorescence staining, and Western blotting.

RESULTS

We extracted EVs from MCPs, and small-RNA sequencing analysis showed miR-148a-3p enrichment in MCPs-EVs. Exogenous MCPs-EV administration effectively promoted mouse cavernous endothelial cell (MCECs) tube formation, migration, and proliferation, and reduced MCECs apoptosis under high-glucose conditions. These effects were significantly attenuated in miR-148a-3p-depleted MCPs-EVs, which were extracted after inhibiting miR-148a-3p expression in MCPs. Repetitive intracavernous injections of MCPs-EVs improved erectile function by inducing cavernous neurovascular regeneration in diabetic mice. Using online bioinformatics databases and luciferase report assays, we predicted that pyruvate dehydrogenase kinase-4 (PDK4) is a potential target gene of miR-148a-3p.

CONCLUSIONS

Our findings provide new and reliable evidence that miR-148a-3p in MCPs-EVs significantly enhances cavernous neurovascular regeneration by inhibiting PDK4 expression in diabetic mice.

Erectile dysfunction and exosome therapy

Erectile dysfunction (ED), as a common male disease, can seriously reduce the life quality of men and their partners. With the improvement of human living standards, ED is considered to be an important health issue that plagues men. However, it is difficult for existing therapeutic approaches to meet the needs of all patients, so it is necessary to develop novel treatment strategies. Exosomes, as a class of vesicles secreted by cells with bilayer membrane structure, are involved in various physiological and pathological processes in human body and considered to have great therapeutic potentials. This review summarizes the recent advances on exosome therapy with animal models of ED, and proposes the prospect of future research in order to provide a basis for clinical trials and clinical translation.

The Emerging Role of Pericyte-Derived Extracellular Vesicles in Vascular and Neurological Health

Pericytes (PCs), as a central component of the neurovascular unit, contribute to the regenerative potential of the central nervous system (CNS) and peripheral nervous system (PNS) by virtue of their role in blood flow regulation, angiogenesis, maintenance of the BBB, neurogenesis, and neuroprotection. Emerging evidence indicates that PCs also have a role in mediating cell-to-cell communication through the secretion of extracellular vesicles (EVs). Extracellular vesicles are cell-derived, micro- to nano-sized vesicles that transport cell constituents such as proteins, nucleic acids, and lipids from a parent originating cell to a recipient cell. PC-derived EVs (PC-EVs) play a crucial homeostatic role in neurovascular disease, as they promote angiogenesis, maintain the integrity of the blood-tissue barrier, and provide neuroprotection. The cargo carried by PC-EVs includes growth factors such as endothelial growth factor (VEGF), connecting tissue growth factors (CTGFs), fibroblast growth factors, angiopoietin 1, and neurotrophic growth factors such as brain-derived neurotrophic growth factor (BDNF), neuron growth factor (NGF), and glial-derived neurotrophic factor (GDNF), as well as cytokines such as interleukin (IL)-6, IL-8, IL-10, and MCP-1. The PC-EVs also carry miRNA and circular RNA linked to neurovascular health and the progression of several vascular and neuronal diseases. Therapeutic strategies employing PC-EVs have potential in the treatment of vascular and neurodegenerative diseases. This review discusses current research on the characteristic features of EVs secreted by PCs and their role in neuronal and vascular health and disease.

Small extracellular vesicles derived from hypoxic mesenchymal stem cells promote vascularized bone regeneration through the miR-210-3p/EFNA3/PI3K pathway

Angiogenesis is closely coupled with osteogenesis and has equal importance. Thus, promoting angiogenesis during the bone repair process is vital for ideal bone regeneration. As important mediators of cell-cell communication and biological homeostasis, mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been proved to be highly involved in bone and vascular regeneration. Because hypoxia microenvironment promotes the proangiogenic activity of MSCs, in the present study, we investigate the effect and underlying molecular mechanisms of sEVs from hypoxia-preconditioned MSCs (hypo-sEVs) on angiogenesis and develop an effective strategy to promote vascularized bone regeneration. Compared to sEVs from normoxia MSCs (nor-sEVs), hypo-sEVs promoted the proliferation, migration, and angiogenesis of HUVECs and ultimately enhanced bone regeneration and new blood vessel reconstruction in a critical-size calvarial bone defect model. miRNA sequence and the verified results showed that miR-210-3p in hypo-sEVs was increased via HIF-1α under hypoxia. The upregulated miR-210-3p in hypo-sEVs promoted angiogenesis by downregulating EFNA3 expression and enhancing the phosphorylation of the PI3K/AKT pathway. Thus, this study suggests a successful strategy to enhance vascularized bone regeneration by utilizing hypo-sEVs via the miR-210-3p/EFNA3/PI3K/AKT pathway. STATEMENT OF SIGNIFICANCE: Considering the significance of vascularization in ideal bone regeneration, strategies to promote angiogenesis during bone repair are required. Hypoxia microenvironment can promote the proangiogenic potential of mesenchymal stem cells (MSCs). Nonetheless, the therapeutic effect of small extracellular vesicles (sEVs) from hypoxia-preconditioned MSCs on cranio-maxillofacial bone defect remains unknown, and the underlying mechanism is poorly understood. This study shows that hypo-sEVs significantly enhance the proliferation, migration, and angiogenesis of HUVECs as well as promote vascularized bone formation. Moreover, this work indicates that HIF-1α can induce overexpression of miR-210-3p under hypoxia, and miR-210-3p can hinder EFNA3 expression and subsequently activate the PI3K/AKT pathway. The application of hypo-sEVs provides a facile and promising strategy to promote vascularized bone regeneration in a critical-size bone defect model.

The Role of Extracellular Vesicles in Cancer-Nerve Crosstalk of the Peripheral Nervous System

Although the pathogenic operations of cancer–nerve crosstalk (e.g., neuritogenesis, neoneurogensis, and perineural invasion—PNI) in the peripheral nervous system (PNS) during tumorigenesis, as well as the progression of all cancer types is continuing to emerge as an area of unique scientific interest and study, extensive, wide-ranging, and multidisciplinary investigations still remain fragmented and unsystematic. This is especially so in regard to the roles played by extracellular vesicles (EVs), which are lipid bilayer-enclosed nano- to microsized particles that carry multiple-function molecular cargos, facilitate intercellular communication in diverse processes. Accordingly, the biological significance of EVs has been greatly elevated in recent years, as there is strong evidence that they could contribute to important and possibly groundbreaking diagnostic and therapeutic innovations. This can be achieved and the pace of discoveries accelerated through cross-pollination from existing knowledge and studies regarding nervous system physiology and pathology, as well as thoroughgoing collaborations between oncologists, neurobiologists, pathologists, clinicians, and researchers. This article offers an overview of current and recent past investigations on the roles of EVs in cancer–nerve crosstalk, as well as in neural development, physiology, inflammation, injury, and regeneration in the PNS. By highlighting the mechanisms involved in physiological and noncancerous pathological cellular crosstalk, we provide hints that may inspire additional translational studies on cancer–nerve interplay.

Pericyte‑derived extracellular vesicles‑mimetic nanovesicles improves peripheral nerve regeneration in mouse models of sciatic nerve transection

Pericyte‑derived extracellular vesicle‑mimetic nanovesicles (PC‑NVs) play an important role in the improvement of erectile function after cavernous nerve injury. However, the impact of PC‑NVs on the peripheral nervous system (PNS), such as the sciatic nerve, is unclear. In this study, PC‑NVs were isolated from mouse cavernous pericytes (MCPs). A sciatic nerve transection (SNT) model was established using 8‑week‑old C57BL/6J mice. The sciatic nerve was harvested 5 and 14 days for immunofluorescence and western blot studies. Function studies were evaluated by performing the rotarod test and walking track analysis. The results demonstrated that PC‑NVs could stimulate endothelial cells, increase neuronal cell content, and increase macrophage and Schwann cell presence at the proximal stump rather than the distal stump in the SNT model, thereby improving angiogenesis and nerve regeneration in the early stage of sciatic nerve regeneration. In addition, PC‑NVs also increased the expression of neurotrophic factors (brain‑derived nerve growth factor, neurotrophin‑3 and nerve growth factor) and the activity of the cell survival signaling pathway (PI3K/Akt signaling), and reduced the activity of the JNK signaling pathway. Additionally, after 8 weeks of local application of PC‑NVs in SNT model mice, their motor and sensory functions were significantly improved, as assessed by performing the rotarod test and walking track analysis. In conclusion, the present study showed that the significant improvement of neurovascular regeneration in mice following treatment with PC‑NVs may provide a favorable strategy for promoting motor and sensory regeneration and functional recovery of the PNS.

The protective effects of pericyte-derived microvesicles on vascular endothelial functions via CTGF delivery in sepsis

BACKGROUND

It is well known that sepsis is a prevalent severe disease caused by infection and the treatment strategies are limited. Recently pericyte-derived microvesicles (PMVs) were confirmed to be therapeutic in many diseases, whether PMVs can protect vascular endothelial cell (VEC) injury is unknown.

METHODS

Pericytes were extracted from the retina of newly weaned rats, and PMVs were collected after starvation and characterized by flow-cytometry and transmission electron microscopy. First, the effect of PMVs on pulmonary vascular function in septic rats was measured via intravenous administration with HE staining, immunofluorescence, and Elisa analysis. Then, PMVs were co-incubated with VECs in the presence of lipopolysaccharide (LPS), and observed the protective effect of PMVs on VECs. Next, the proteomic analysis and further Gene Ontology (GO) enrichment analysis were performed to analyze the therapeutic mechanism of PMVs, and the angiogenesis-related protein CTGF was highly expressed in PMVs. Finally, by CTGF upregulation and downregulation in PMV, the role of PMV-carried CTGF was investigated.

RESULTS

PMVs restored the proliferation and angiogenesis ability of pulmonary VECs, and alleviated pulmonary vascular leakage in septic rats and LPS-stimulated VECs. Further study showed that PMVs delivered CTGF to VECs, and subsequently activated ERK1/2, and increased the phosphorylation of STAT3, thereby improving the function of VECs. The further study found CD44 mediated the absorption and internalization of PMVs to VECs, the anti-CD44 antibody inhibited the protective effect of PMVs.

CONCLUSIONS

PMVs may delivery CTGF to VECs, and promote the proliferation and angiogenesis ability by activating the CTGF-ERK1/2-STAT3 axis, thereby protecting pulmonary vascular function in sepsis. The therapeutic effect of PMVs was highly related to CD44-mediated absorption. Video Abstract.

RNA-sequencing profiling analysis of pericyte-derived extracellular vesicle-mimetic nanovesicles-regulated genes in primary cultured fibroblasts from normal and Peyronie's disease penile tunica albuginea

BACKGROUND

Peyronie's disease (PD) is a severe fibrotic disease of the tunica albuginea that causes penis curvature and leads to penile pain, deformity, and erectile dysfunction. The role of pericytes in the pathogenesis of fibrosis has recently been determined. Extracellular vesicle (EV)-mimetic nanovesicles (NVs) have attracted attention regarding intercellular communication between cells in the field of fibrosis. However, the global gene expression of pericyte-derived EV-mimetic NVs (PC-NVs) in regulating fibrosis remains unknown. Here, we used RNA-sequencing technology to investigate the potential target genes regulated by PC-NVs in primary fibroblasts derived from human PD plaque.

METHODS

Human primary fibroblasts derived from normal and PD patients was cultured and treated with cavernosum pericytes isolated extracellular vesicle (EV)-mimetic nanovesicles (NVs). A global gene expression RNA-sequencing assay was performed on normal fibroblasts, PD fibroblasts, and PD fibroblasts treated with PC-NVs. Reverse transcription polymerase chain reaction (RT-PCR) was used for sequencing data validation.

RESULTS

A total of 4135 genes showed significantly differential expression in the normal fibroblasts, PD fibroblasts, and PD fibroblasts treated with PC-NVs. However, only 91 contra-regulated genes were detected among the three libraries. Furthermore, 20 contra-regulated genes were selected and 11 showed consistent changes in the RNA-sequencing assay, which were validated by RT-PCR.

CONCLUSION

The gene expression profiling results suggested that these validated genes may be good targets for understanding potential mechanisms and conducting molecular studies into PD.