PPP1R14A in male erectile dysfunction: key role in smooth muscle cells.

Background: Erectile dysfunction (ED) is a prevalent male health condition impairing quality of life. Existing therapies have limited efficacy, so novel pharmacological targets and clear molecular mechanisms of ED are needed. Aim: This study aims to integrate single-cell RNA sequencing (scRNA-seq) and genome-wide association studies (GWAS) analysis to uncover potential therapeutic targets for ED and clarify its molecular mechanisms. Methods: The study synthesized data from ED GWAS, scRNA-seq, protein quantitative trait loci, and expression quantitative trait loci datasets. Two-sample Mendelian randomization (MR) analysis, with instrumental variable weighted as the main method, was used to assess protein-ED causal relationships. Molecular docking screened candidate compounds, and murine penis experiments validated differential expression. Outcomes: Reveal the key molecular targets and regulatory mechanisms of ED pathogenesis, screen potential targeted drugs, and provide theoretical and experimental basis for the precise treatment of ED. Results: After scRNA-seq preprocessing, 2579 differentially expressed genes across five cell types were identified. MR analysis found 113 plasma proteins significantly associated with ED. Among overlapping genes, 4 eQTLs were ED-related, with PPP1R14A showing the strongest association (OR = 1.27; 95% CI, 1.10-1.45; P_IVW = 0.0007). PPP1R14A was predominantly expressed in smooth muscle cells (SMCs) and upregulated in ED patients. Pathway enrichment analysis revealed that PPP1R14A and its co-expressed genes are primarily involved in vascular smooth muscle contraction, actin phosphorylation, and calcium homeostasis. Progesterone and ampicillin were identified as potential binding candidates. Diabetic and elderly mice (with lower intracavernous pressure) had significantly higher PPP1R14A expression in cavernous tissue. Clinical Translation: PPP1R14A can serve as a new candidate target for targeted therapy of ED. Potential binding compounds such as progesterone and ampicillin provide directions for subsequent drug development and lay the foundation for precise treatment of ED (especially diabetes-related and senile ED). Strengths and Limitations: The advantage lies in the systematic analysis of the ED mechanism through multi-omics integration (scRNA-seq + MR + proteomics), clarifying cell-specific expression and causal relationships; the limitations are the limited sample size, the lack of direct in vivo and in vitro functional verification experiments, the need for further clinical verification of the safety and efficacy of drug candidates, and the failure to cover all ED subtypes and ethnic diversity. Conclusion: PPP1R14A plays a key role in the pathogenesis of ED. It affects the erectile process by regulating the function of SMCs. This study provides new insights into the molecular mechanism of ED and also offers important support for the development of targeted therapeutic drugs.