hsa_circ_0000417 downregulation suppresses androgen receptor expression and apoptotic signals in human foreskin fibroblasts via sponging miR-6756-5p.

BACKGROUND: Dysregulated apoptosis of penile mesenchymal cells during male urethragenesis has been previously demonstrated to underly hypospadiac urethral closure failure, and androgen receptor (AR) has been shown to play a central role in regulating penile mesenchyme cell proliferation and survival. However, the regulatory mechanisms upstream and downstream of AR remain poorly understood. Our clinical data and bioinformatics analysis previously indicated that hsa_circ_0000417, a circRNA significantly downregulated in hypospadias preputial specimens, may act as a ceRNA for AR via sequestering hsa_miR-6756-5p, and that the biological functions of hsa_circ_0000417 may significantly involve the PI3K/AKT pathway. In this study, we employed human foreskin fibroblasts (HFF-1) to experimentally validate this putative hsa_circ_0000417/miR-6756-5p/AR axis and its impact on penile mesenchymal cell proliferation and apoptosis. METHOD AND RESULTS: We showed that hsa_circ_0000417 knockdown significantly promoted proliferation and suppressed apoptosis of HFF-1 cells. Mechanistically, hsa_circ_0000417 functioned as a molecular sponge for miR-6756-5p in HFF-1 cells and relieved the latter's translational repression on AR mRNA, leading to decreased AKT activation and increased expression of pro-apoptotic proteins BAX and cleaved-caspase 9. Conversely, elevated levels of miR-6756-5p resulted in diminished AR expression concomitant with enhanced AKT activation and HFF-1 cell proliferation. CONCLUSIONS: Collectively, our data describe for the first time a circRNA-mediated post-transcriptional regulatory mechanism of AR and its functional consequences in penile mesenchymal cells in the context of hypospadias. These findings may contribute to advancing our current understanding of the roles of AR and mesenchymal cell fate decisions during penile morphogenesis.

The involvement of hsa_circ_0000417 in the development of hypospadias by regulating AR.

BACKGROUND: Congenital hypospadias is a common congenital malformation of the urinary system in male children. However, the role of circRNA in congenital hypospadias remains unknown. METHODS: Differentially expressed circRNAs and mRNAs were identified by RNA sequencing. GO and KEEG analysis were performed to uncover the key function and pathways. The interaction networks were constructed and analyzed by competing endogenous (ce)RNA analysis. Immunohistochemistry (IHC) and qRT-PCR were used to detect the expressions of androgen receptor (AR) and hsa_circ_0000417 in normal and hypospadias tissues. Further, the correlation between hsa_circ_0000417 and other clinical indicators were calculated. RESULTS: Compared with normal foreskin tissues, 1329 circRNAs and 978 mRNAs were significantly upregulated, 3176 circRNAs and 614 mRNAs were significantly downregulated in hypospadias tissues, respectively. MAPK and PI3K-Akt signaling pathways play important roles in congenital hypospadias. The expression of AR and hsa_circ_0000417 in 68 hypospadias tissues was significantly lower than that in 68 normal foreskin tissues (P < 0.05). The expression of the AR, as analyzed using IHC, was consistent with the qPCR results. A significant correlation was noted between the expression of AR and hsa_circ_0000417 in 68 clinical samples (P < 0.05). Furthermore, the expression level of hsa_circ_0000417 was associated with the incidence of other diseases and the location of the hypospadias site (P < 0.05). Expression of hsa_circ_0000417 was significantly downregulated in hypospadias patients without other diseases (P < 0.05). CONCLUSION: Hsa_circ_0000417 may regulate the expression of AR, and the expression of hsa_circ_0000417 in normal foreskin tissues is associated with the occurrence of hypospadias.

MiR-135a-5p and Mst1 regulate MPP + -1 induced apoptosis and autophagy in Parkinson's disease model in vitro.

The mammalian Ste20-like kinases 1 (Mst1) is essential for regulating cell proliferation, differentiation, apoptosis, and autophagy. However, the molecular mechanisms of Mst1 in neuronal cell death remains incompletely understood. Here, we showed that Mst1 is up-regulated in Parkinson's disease (PD) model induced by MPP+. Knockdown of Mst1 resulted in a reduction in MPP+-induced apoptosis and autophagy in SH-SY5Y and CHP 212 cells. Mechanistically, Mst1 silencing suppressed autophagy by activating mTOR/ULK1/S6K1 pathway. We also showed that miR-135a-5p was lower while Mst1 was inversely higher in MPP+-treated cells. Furthermore, miR-135a-5p has a protective role on MPP+-induced neuronal cell death via targeting Mst1. On the whole, the miR-135a-5p/Mst1 axis might serve as a potential therapeutic target in PD treatment.

The effect of staged TIP urethroplasty on proximal hypospadias with severe chordee.

Background: Proximal hypospadias with severe chordee is still a formidable challenge for most pediatric urologists, and the treatment approach remains controversial. Here, we describe a modified two-stage technique to repair proximal hypospadias with severe chordee. Methods: We retrospectively identified 53 children referred for proximal hypospadias with severe chordee from July 2016 to July 2019, who underwent a two-stage urethroplasty. In group 1, the children were repaired with staged tubularized incised plate (TIP) urethroplasty, while Byars' two-stage urethroplasty was attempted in group 2. We corrected chordee by releasing all remaining attachments to the corpora after degloving the penis, transceting the urethral plate, and dorsal plication. The mean age of patients in the first stage of surgery was 26.6 months in group 1 and 24.8 months in group 2. Postoperative complications in the two groups included: fistula, urethral stricture, urethral diverticulum, and glanular dehiscence. Results: A total of 20 cases were repaired with staged TIP urethroplasty (group 1), and 33 cases were repaired with Byars' two-stage urethroplasty (group 2). The length of follow-up in group 1 was 39.8 ± 10.1 months, and in group 2, it was 38.1 ± 8.7 months (P > 0.05). After the second stage of surgery, 1 case (5%) in group 1 and 11 cases (33.3%) in group 2 developed a urinary fistula (P < 0.05). One case (5%) in group 1 and three cases (9.1%) in group 2 had urethral stricture (P > 0.05). All strictures were cured by repeated dilation, and no patient required reoperation. No cases in group 1 and one case (3%) in group 2 had urethral diverticulum (P > 0.05). There was no residual chordee in both groups. Two cases (10%) in group 1 and 13 cases (39.3%) in group 2 required reoperation (P < 0.05). Conclusions: Staged urethroplasty is appropriate to repair proximal hypospadias with severe chordee. Particularly, staged TIP urethroplasty is a good choice for patients with proximal hypospadias and severe chordee, especially those with better penile development, wider urethral plate, larger glans, and deeper navicular fossa of the urethra.