Purpose: To assess the diverse cell populations of human corpus cavernosum in patients with severe erectile dysfunction (ED) at the single-cell level.Methods: Penile tissues collected from three patients were subjected to single-cell RNA sequencing using the BD Rhapsody™ platform. Common bioinformatics tools were used to analyze cellular heterogeneity and gene expression profiles from generated raw data, including the packages Seurat, Monocle, and CellPhoneDB.Results: Disease-related heterogeneity of cell types was determined in the cavernous tissue such as endothelial cells (ECs), smooth muscle cells, fibroblasts, and immune cells. Reclustering analysis of ECs identified an arteriole ECs subcluster and another one with gene signatures of fibroblasts. The proportion of fibroblasts was higher than the other cell populations and had the most significant cellular heterogeneity, in which a distinct subcluster co-expressed endothelial markers. The transition trajectory of differentiation from smooth muscle cells into fibroblasts was depicted using the pseudotime analysis, suggesting that the expansion of corpus cavernosum is possibly compromised as a result of fibrosis. Cell-cell communications among ECs, smooth muscle cells, fibroblasts, and macrophages were robust, which indicated that inflammation may also have a crucial role in the development of ED.Conclusions: Our study has demonstrated a comprehensive single-cell atlas of cellular components in human corpus cavernosum of ED, providing in-depth insights into the pathogenesis. Future research is warranted to explore disease-specific alterations for individualized treatment of ED.

Bovine milk-derived extracellular vesicles (BM-EVs) are recognized as promising nanoscale delivery vectors owing to their large availability. However, few isolation methods can achieve high purity and yield simultaneously. Therefore, we developed a novel and cost-effective procedure to separate BM-EVs via “salting-out.” First, BM-EVs were isolated from skimmed milk using ammonium sulfate. The majority of BM-EVs were precipitated between 30 and 40% saturation and 34% had a relatively augmented purity. The separated BM-EVs showed a spherical shape with a diameter of 60–150 nm and expressed the marker proteins CD63, TSG101, and Hsp70. The purity and yield were comparable to the BM-EVs isolated via ultracentrifugation while ExoQuick failed to separate a relatively pure fraction of BM-EVs. The uptake of BM-EVs into endothelial cells was dose- and time-dependent without significant cytotoxicity. The levels of endothelial nitric oxide syntheses were regulated by BM-EVs loaded with icariside II and miRNA-155-5p, suggesting their functions as delivery vehicles. These findings have demonstrated that it is an efficient procedure to isolate BM-EVs via “salting-out,” holding great promise toward therapeutic applications.

Aim: The aim of the study was to investigate whether miR-126, a regulator of MAPK signaling via targeting sprouty-related EVH1 domain-containing protein 1 (SPRED1) mRNA, is involved in the process by which icariside II (ICA II) ameliorates endothelial dysfunction in human cavernous endothelial cells (hCECs) exposed to a diabetic-like environment. Materials and methods: Primary hCECs were isolated and divided into three groups, normal control, diabetes mellitus (DM), and DM treated with ICA II. The cell proliferation and migration abilities of the hCECs were examined. The expression levels of endothelial-related microRNAs and relative target mRNAs (SPRED1, phosphoinositol-3 kinase regulatory subunit 2, and vascular cell adhesion molecule 1) of miR-126 were determined by real-time PCR. The protein expression of endothelial nitric oxide synthase, receptor for advanced glycation end products, and SPRED1, and MAPK signaling activities was determined by Western blot analysis. In addition, miR-126 agomir and antagomir were used for transfection into hCECs to further testify the association between miR-126 and its targeting mRNA SPRED1. Results: hCECs induced with glucose plus advanced glycation end product-BSA showed a significant decrease in endothelial nitric oxide synthase, Ki-67, and miR-126 expression; a downregulated cell migration ability and an increased receptor for advanced glycation end products level. ICA II could partially reverse these changes. SPRED1 mRNA showed a contrary tendency with the miR-126-3p changes. The level of SPRED1 protein increased after the hCECs were induced with glucose plus advanced glycation end product-BSA, and ICA II could rescue its aberrant expression. In addition, the MAPK pathway was downregulated in the hCECs under diabetic conditions, and ICA II could partially enhance its signaling activities. miR-126 was obviously downregulated, and SPRED1 was accordingly upregulated after miR-126 antagomir transfection, while ICA II treatment could recover the expressions of both miR-126 and SPRED1. Moreover, the upregulation of miR-126 and the inhibition of SPRED1 were noticed in the diabetic hCECs by further transfection with miR-126 agomir. Conclusion: ICA II could ameliorate endothelial dysfunction by regulating the MAPK pathway via miR-126/SPRED1 in hCECs exposed to a diabetic-like environment, and ICA II might be a protective agent for endothelial function in diabetic ED.

Background: Endothelial dysfunction is commonly accompanied by a reduced capacity for nitric oxide (NO) production and decreased NO sensitivity, playing a central role in numerous vascular diseases. Saturated free fatty acids are known to reduce NO production and then induce endothelial dysfunction. Alternative splicing participates in the regulation of cellular and tissular homeostasis and is highly regulated by serine-arginine protein kinase (SRPK1). The role of SRPK1 in the biology of endothelial cells remains elusive. Icariside Ⅱ (ICA Ⅱ) has been reported to have protective effects on endothelial function. However, the specific molecular mechanisms are still unknown. The purpose of this study is to explore the role of SRPK1 in the biology of endothelial cells and the underlying mechanism of ICA Ⅱ on palmitic acid (PA) induced endothelial dysfunction.Methods: Endothelial dysfunction was induced using PA in human umbilical vein endothelial cells (HUVECs). The expression and phosphorylation of related proteins in the SRPK1-Akt-eNOS signaling pathway were detected by Western Blot. Cell Counting Kit-8 assay and Ki-67 immunofluorescence were used to estimate cell viability. Endothelial cell function was assessed by detecting NO production using DAF-FM DA. Interaction between ICA Ⅱ and SRPK1 was demonstrated by a biotinylated protein interaction pull-down assay.Results: The expressions of eNOS, Akt, and SRPK1 were down-regulated in the endothelial dysfunction stimulated by PA. SRPK1 inhibitor SPHINX31 restrained endothelial cell viability in a dose-dependent manner. Moreover, inhibition of SRPK1 using SPHINX31 and knockdown of SRPK1 by shRNA also showed a down-regulation of the proteins associated with the SRPK1-Akt-eNOS signaling pathway. Biotinylated protein interaction pull-down assay revealed that ICA Ⅱ could be directly bound with SRPK1. On the other hand, ICA Ⅱ could attenuate the PA-induced endothelial dysfunction and restore cell viability through the SRPK1-Akt-eNOS pathway.Conclusions: ICA Ⅱ, bound with SRPK1, could attenuate the endothelial dysfunction induced by the PA in HUVECs via the SRPK1-Akt-eNOS signaling pathway.