# Multi-omics analysis the effects of Dhx37 deficiency on testis development and nucleolar homeostasis

## TL;DR

This study shows that the gene Dhx37 is crucial for testis development by maintaining nucleolar structure and preventing cell death in Sertoli cells.

## Contribution

The study identifies Dhx37 as a novel regulator of nucleolar homeostasis and testicular development in mice.

## Key findings

- Dhx37 deficiency leads to disrupted nucleolar structure and increased apoptosis in Sertoli cells.
- Loss of Dhx37 results in reduced testicular volume and impaired spermatogenesis in mice.
- Dhx37 regulates the PI3K–AKT signaling pathway and suppresses p53-driven apoptosis.

## Abstract

The testicular microenvironment, with Sertoli cells as a key component, plays a pivotal role in spermatogenesis. DHX37, a member of the DEAH-box family of RNA helicases, has been identified as a pathogenic gene in 46, XY disorders of sex development (DSD), underscoring its potential significance in testicular development. Here, we focus on elucidating the role of Dhx37 in maintaining Sertoli-cell survival. RIP-seq and RNAi-RNA-seq reveal that Dhx37 safeguards nucleolar integrity and PI3K–AKT signaling, suppresses p53-driven apoptosis, and its loss triggers pro-apoptotic splicing. Cell-specific Dhx37 knockout mice (Dhx37−/−) were subsequently generated to investigate the function of Dhx37 in testicular development. In the Dhx37−/− mice, we observed pronounced defects, including diminished testicular volume, lower testosterone levels, and marked vacuolization of the seminiferous tubules. Immunofluorescence staining revealed disruptions in both Sertoli and germ cell compartments, characterized by reduced cell proliferation and elevated apoptosis. The snRNA-seq disclosed marked changes in the expression of genes governing apoptosis and proliferation, findings that were further validated through qRT-PCR and Western blotting. In this study, we identified Dhx37 as a pivotal determinant of nucleolar architecture in murine testicular Sertoli cells. Preservation of the nucleolus safeguards supporting normal testicular morphogenesis.

Graphical Abstract Schematic illustrating the proposed mechanisms by which Dhx37 deficiency affects testicular development and spermatogenesis. In normal testes (left), Sertoli cells maintain a well-organized nucleolus with intact nucleolar structures, including Granular Component (GC), Fibrillar Center (FC), Dense Fibrillar Component (DFC). In this context, MDM2 interacts with P53, preventing the accumulation of P53 and inhibiting apoptosis, thereby supporting normal testicular architecture and spermatogenesis. However, in Dhx37−/− mice (right), testicular volume is reduced, and seminiferous tubules undergo atrophy due to nucleolar stress in Sertoli cells. The disruption of nucleolar structure leads to the export of FBL from the nucleolus, where it binds to MDM2. This disruption is accompanied by downregulation of key factors in the PI3K pathway (Fgf2, Lpar2, PI3KR2, PI3KR5) and upregulation of the P53 pathway, culminating in apoptosis. As a result, Dhx37 deficiency impairs Sertoli cell function, leading to a failure in supporting testicular development and spermatogenesis. Created with BioGDP.com.

Graphical Abstract Schematic illustrating the proposed mechanisms by which Dhx37 deficiency affects testicular development and spermatogenesis. In normal testes (left), Sertoli cells maintain a well-organized nucleolus with intact nucleolar structures, including Granular Component (GC), Fibrillar Center (FC), Dense Fibrillar Component (DFC). In this context, MDM2 interacts with P53, preventing the accumulation of P53 and inhibiting apoptosis, thereby supporting normal testicular architecture and spermatogenesis. However, in Dhx37−/− mice (right), testicular volume is reduced, and seminiferous tubules undergo atrophy due to nucleolar stress in Sertoli cells. The disruption of nucleolar structure leads to the export of FBL from the nucleolus, where it binds to MDM2. This disruption is accompanied by downregulation of key factors in the PI3K pathway (Fgf2, Lpar2, PI3KR2, PI3KR5) and upregulation of the P53 pathway, culminating in apoptosis. As a result, Dhx37 deficiency impairs Sertoli cell function, leading to a failure in supporting testicular development and spermatogenesis. Created with BioGDP.com.