Department of Urology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, China.
Department of Urology, Zhejiang Hospital, Hangzhou City, Zhejiang Province, China.
J Sex Med. 2024 May 28;21(6):511-521. doi: 10.1093/jsxmed/qdae021.
Erectile dysfunction (ED), defined as the inability to achieve or maintain a penile erection sufficient to satisfy sexual behavior, is prevalent worldwide.
Using previous research, bioinformatics, and experimental confirmation, we aimed to discover genes that contribute to ED through regulating hypoxia in corpus cavernosum smooth muscle cells (CCSMCs).
We used the Gene Expression Omnibus to acquire the sequencing data of the corpus cavernosum transcriptome for diabetic ED and nerve injury type ED rats. We intersected the common differentially expressed genes. Further verification was performed using single cell sequencing. Real-time quantitative polymerase chain reaction and immunofluorescence were used to investigate whether the differentially expressed genes are found in the corpus cavernosum. We used induced hypoxia to assess cell viability changes, and we developed a lentivirus overexpressing Cldn4 for in vitro and in vivo experiments to measure changes in JNK signaling, fibrosis, hypoxia, and erectile function.
Our results indicate that targeting the JNK pathway and decreasing local hypoxia may be better options for therapeutic intervention to improve erectile function.
We identified Cldn4 and found its expression increased in the corpora cavernosa of the 2 datasets. In addition, we found that hypoxia can increase the expression of Cldn4, activate the JNK signaling pathway, and exacerbate fibrosis in CCSMCs. Cldn4 overexpression in CCSMCs activated the JNK signaling pathway and increased fibrotic protein expression. Last, rat corpus cavernosum overexpressing Cldn4 activated the JNK signaling pathway, increased local fibrosis, and impaired erectile function.
Through bioinformatics and in vitro and in vivo experiments, we found that Cldn4 has a negative effect on ED, and targeting Cldn4 may provide new ideas for ED treatment.
Although we have identified Cldn4 as a potential target for ED treatment, we have only conducted preliminary validation on CCMSCs, and we still need to further validate in other cell lines.
CCSMC hypoxia leads to increased Cldn4, in both nerve injury and diabetic ED rat models, and promotes fibrosis by activating the JNK signaling pathway.
勃起功能障碍（ED）定义为阴茎无法勃起或维持足够硬度以满足性行为，其在全球范围内普遍存在。
通过调控海绵体平滑肌细胞缺氧，利用既往研究、生物信息学和实验验证发现与 ED 相关的基因。
通过基因表达综合数据库（GEO）获取糖尿病 ED 和神经损伤型 ED 大鼠海绵体转录组测序数据，取其交集，进一步通过单细胞测序进行验证，实时定量聚合酶链反应（PCR）和免疫荧光技术检测 ED 大鼠海绵体中差异表达基因是否存在，通过诱导缺氧评估细胞活力变化，构建 Cldn4 过表达慢病毒，进行体外和体内实验，检测 JNK 信号通路、纤维化、缺氧和勃起功能的变化。
我们发现 Claudin4（Cldn4）并证实其在 2 个数据集的海绵体中表达增加。此外，我们发现缺氧可增加 Cldn4 的表达，激活 JNK 信号通路，加重 CCSMC 纤维化。CCSMCs 中 Cldn4 的过表达激活了 JNK 信号通路，并增加了纤维蛋白的表达。最后，过表达 Cldn4 的大鼠海绵体激活了 JNK 信号通路，增加了局部纤维化，损害了勃起功能。
通过生物信息学和体外、体内实验，我们发现 Cldn4 对 ED 有负面影响，靶向 Cldn4 可能为 ED 治疗提供新的思路。
尽管我们已经确定 Claudin4 是 ED 治疗的潜在靶点，但我们仅在 CCMSCs 上进行了初步验证，仍需要在其他细胞系中进一步验证。
