Targeting against the activity of the NLRP3 inflammasome is a potential therapy for rat testicular tissue cryopreservation and transplantation

Vitamin D protects spermatogonia and Sertoli cells from heat stress damage by inhibiting NLRP3

Introduction

Cryptorchidism can damage cells in the cryptorchid testes due to elevated local temperatures, potentially impacting the fertility of the child in adulthood. Research indicates that vitamin D enhances sperm quality in adult males. This study aimed to explore whether vitamin D inhibits NLRP3 activation, thus helping to mitigate heat stress damage to testicular spermatogenic and Sertoli cells.

Materials and methods

Five cases of normal testicular tissue adjacent to a tumor (testis removed due to tumorous growth) and five cases of atrophied cryptorchid testicular tissue (testis removed) were analyzed for immunohistochemistry to determine NLRP3 expression in cryptorchid tissue. In Phase I, spermatogonia (GC-1) and Sertoli cells (TM4) were separated into blank and heat stress groups. Apoptosis, inflammatory factor levels, and the expression of Bcl-2 and NLRP3 genes and proteins were measured at 2, 6, and 10 h after heat stress treatment. In Phase II, the cells were re-cultured and divided into three groups: heat stress, siRNA + heat stress, and VD + heat stress. After 10 h, the apoptosis, inflammatory factor levels, and gene and protein expressions of Bcl-2 and NLRP3 were reassessed in each group.

Results

Immunohistochemistry indicated NLRP3 expression in cryptorchid tissue. Phase I, extending heat stress duration led to increased apoptosis in spermatogonia (GC-1) and testicular Sertoli cells (TM4), heightened levels of inflammatory factors, reduced BCL-2 expression, and elevated NLRP3 expression compared to the control group. Phase II, both the siRNA + heat stress and VD + heat stress groups showed decreased apoptosis in spermatogonia and Sertoli cells, lower inflammatory factor levels, increased BCL-2 expression, and decreased NLRP3 expression compared to the heat stress-only group, with statistically significant differences (P < 0.05).

Conclusions

This is the first time we found the expression of NLRP3 in cryptorchidism. Vitamin D can inhibit the expression of NLRP3 and reduce the damage of heat stress on testicular spermatogenic cells and Sertoli cells, and play a protective role for testicular spermatogenic cells and Sertoli cells. This provides a theoretical basis for preserving testicular function during the "treatment gap" in boys with cryptorchidism who have not received surgical treatment.

Automatic Evaluation for Bioengineering of Human Artificial Ovary: A Model for Fertility Preservation for Prepubertal Female Patients with a Malignant Tumor

Introduction: The in vitro culture of primordial follicles is the only available option for preserving fertility in prepubertal girls with malignant tumors. The cultivation of primordial follicles in scaffolds as artificial ovaries is a promising approach for this. Methods: Dissociated follicles were placed into an artificial ovarian scaffold composed of fibrinogen and thrombin. The follicles were cultured in a dish dedicated to live cell imaging and observed for growth using immunofluorescence and development via optical microscopy. The morphology of the follicles in the scaffold was three-dimensionally reconstructed using the Imaris software. Growth and development were also quantified. Results: The morphology of artificial ovaries began to degrade over time. Within approximately 7 days, primordial follicles were activated and grew into secondary follicles. A comparison of optical and confocal microscopy results revealed the superior detection of live cells using confocal microscopy. The three-dimensional reconstruction of the confocal microscopy data enabled the automatic enumeration and evaluation of the overall morphology of many follicles. Conclusions: The novel artificial ovary-enabled primordial follicles to enter the growth cycle after activation and grow into secondary follicles. The use of a fibrin scaffold as a carrier preserves the developmental potential of primordial germ cells and is a potentially effective method for preserving fertility in prepubertal girls.

NLRP3 inflammasome: A potential therapeutic target to minimize renal ischemia/reperfusion injury during transplantation

Renal transplantation is currently the best treatment option for patients with end-stage kidney disease. Ischemia/reperfusion injury (IRI), which is an inevitable event during renal transplantation, has a profound impact on the function of transplanted kidneys. It has been well demonstrated that innate immune system plays an important role in the process of renal IRI. As a critical component of innate immune system, Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has received great attention from scientific community over the past decade. The main function of NLRP3 inflammasome is mediating activation of caspase-1 and maturation of interleukin (IL)-1β and IL-18. In this review, we summarize the associated molecular signaling events about NLRP3 inflammasome in renal IRI, and highlight the possibility of targeting NLRP3 inflammasome to minimize renal IRI during transplantation.