Long-term culture of human Sertoli cells from adult Klinefelter patients as a first step to develop new tools for unravelling the testicular physiopathology.

Study Question: Are Sertoli cells (SCs) from adult Klinefelter men (47,XXY) capable of proliferating in vitro and maintaining their main phenotypical and functional characteristics as do SCs from adult 46,XY patients?

Summary Answer: Isolated SCs from patients with Klinefelter syndrome (KS) can be expanded in vitro while maintaining their characteristics and a stable karyotype, similar to SCs from 46,XY patients.

What Is Known Already: The mechanism leading to testicular tissue degeneration in KS is still unknown. A few recent studies highlight the main role played by SCs in the physiopathology of the disease, but new study models based on co-culture or testicular organoids are needed to further understand the SC's involvement in the mechanism of testicular degeneration and fibrosis, and to find therapeutical targets.

Microfluidic and Static Organotypic Culture Systems to Support Spermatogenesis From Prepubertal Porcine Testicular Tissue: A Comparative Study.

maturation of immature testicular tissue (ITT) cryopreserved for fertility preservation is a promising fertility restoration strategy. Organotypic tissue culture proved successful in mice, leading to live births. In larger mammals, including humans, efficiently reproducing spermatogenesis remains challenging.

Accelerated and Improved Vascular Maturity after Transplantation of Testicular Tissue in Hydrogels Supplemented with VEGF- and PDGF-Loaded Nanoparticles.

Avascular transplantation of frozen-thawed testicular tissue fragments represents a potential future technique for fertility restoration in boys with cancer. A significant loss of spermatogonia was observed in xeno-transplants of human tissue most likely due to the hypoxic period before revascularization. To reduce the effect of hypoxia-reoxygenation injuries, several options have already been explored, like encapsulation in alginate hydrogel and supplementation with nanoparticles delivering a necrosis inhibitor (NECINH) or VEGF.

Fertility preservation for prepubertal boys: lessons learned from the past and update on remaining challenges towards clinical translation.

Background: Childhood cancer incidence and survivorship are both on the rise. However, many lifesaving treatments threaten the prepubertal testis. Cryopreservation of immature testicular tissue (ITT), containing spermatogonial stem cells (SSCs), as a fertility preservation (FP) option for this population is increasingly proposed worldwide.

The air-liquid interface culture of the mechanically isolated seminiferous tubules embedded in agarose or alginate improves in vitro spermatogenesis at the expense of attenuating their integrity.

Optimization of tissue culture systems able to complete male germ cell maturation to post-meiotic stages is considered as an important matter in reproductive biology. Considering that hypoxia is one of the factors limiting the efficiency of organ culture, the aim of this study was to use isolated seminiferous tubules (STs), having more surface and less thickness, in an organotypic culture system in order to improve oxygen diffusion and reduce hypoxia. The mechanically separated STs embedded in agarose or alginate and 1-3-mm testicular tissue fragments of 3 adult mice were separately placed on the flat surface of agarose gel that was half-soaked in the medium.

Blood Testis Barrier and Somatic Cells Impairment in a Series of 35 Adult Klinefelter Syndrome Patients.

Klinefelter Syndrome (KS) is the most common genetic cause of infertility in men. Degeneration of the testicular tissue starts in utero and accelerates at puberty with hyalinisation of seminiferous tubules, spermatogonia apoptosis and germ cell maturation arrest. Therefore, fertility preservation in young KS boys has been proposed, although this measure is still debated due to insufficient knowledge of the pathophysiology of the disease.

Role of stem cells in fertility preservation: current insights.

While improvements made in the field of cancer therapy allow high survival rates, gonadotoxicity of chemo- and radiotherapy can lead to infertility in male and female pre- and postpubertal patients. Clinical options to preserve fertility before starting gonadotoxic therapies by cryopreserving sperm or oocytes for future use with assisted reproductive technology (ART) are now applied worldwide. Cryopreservation of pre- and postpubertal ovarian tissue containing primordial follicles, though still considered experimental, has already led to the birth of healthy babies after autotransplantation and is performed in an increasing number of centers.

Male fertility preservation in DSD, XXY, pre-gonadotoxic treatments - Update, methods, ethical issues, current outcomes, future directions.

This paper aims at reviewing the fertility preservation strategies that could be considered in several conditions at risk of spermatogonial depletion such as 46,XY disorders of sexual development, Klinefelter syndrome and after gonadotoxic treatment in males highlighting current knowledge on diseases and processes involved in infertility as well as future directions along with their specific ethical issues. While sperm cryopreservation after puberty is the only validated technique for fertility preservation, for prepubertal boys facing gonadotoxic therapies or at risk of testicular tissue degeneration where testicular sperm is not present, cryopreservation of spermatogonial cells may be an option to ensure future parenthood. Promising results with transplantation and in vitro maturation of spermatogonial cells were achieved in animals but so far none of the techniques was applied in humans.

Tissue Engineering to Improve Immature Testicular Tissue and Cell Transplantation Outcomes: One Step Closer to Fertility Restoration for Prepubertal Boys Exposed to Gonadotoxic Treatments.

Despite their important contribution to the cure of both oncological and benign diseases, gonadotoxic therapies present the risk of a severe impairment of fertility. Sperm cryopreservation is not an option to preserve prepubertal boys' reproductive potential, as their seminiferous tubules only contain spermatogonial stem cells (as diploid precursors of spermatozoa). Cryobanking of human immature testicular tissue (ITT) prior to gonadotoxic therapies is an accepted practice.

Role of LRRK2 in the regulation of dopamine receptor trafficking.

Mutations in LRRK2 play a critical role in both familial and sporadic Parkinson's disease (PD). Up to date, the role of LRRK2 in PD onset and progression remains largely unknown. However, experimental evidence highlights a critical role of LRRK2 in the control of vesicle trafficking that in turn may regulate different aspects of neuronal physiology.

Update on fertility restoration from prepubertal spermatogonial stem cells: How far are we from clinical practice?

Fertility preservation in prepubertal boys facing gonadotoxic treatment is still at the experimental stage. Nevertheless cryopreservation of immature testicular tissue (ITT) obtained by small testicular biopsy is being increasingly proposed in reproductive care clinics for this purpose. Different approaches to in vivo or in vitro mature spermatogonial stem cells (SSCs) contained in ITT have been studied: autografting of testicular tissue pieces, transplantation of one's own purified germ cell suspensions, and in vitro maturation (IVM) for subsequent use of sperm for intra cytoplasmic sperm injection (ICSI).

Differential protein-protein interactions of LRRK1 and LRRK2 indicate roles in distinct cellular signaling pathways.

Genetic studies show that LRRK2, and not its closest paralogue LRRK1, is linked to Parkinson's disease. To gain insight into the molecular and cellular basis of this discrepancy, we searched for LRRK1- and LRRK2-specific cellular processes by identifying their distinct interacting proteins. A protein microarray-based interaction screen was performed with recombinant 3xFlag-LRRK1 and 3xFlag-LRRK2 and, in parallel, co-immunoprecipitation followed by mass spectrometry was performed from SH-SY5Y neuroblastoma cell lines stably expressing 3xFlag-LRRK1 or 3xFlag-LRRK2.

LRRK2 affects vesicle trafficking, neurotransmitter extracellular level and membrane receptor localization.

The leucine-rich repeat kinase 2 (LRRK2) gene was found to play a role in the pathogenesis of both familial and sporadic Parkinson's disease (PD). LRRK2 encodes a large multi-domain protein that is expressed in different tissues. To date, the physiological and pathological functions of LRRK2 are not clearly defined.

LRRK2 and vesicle trafficking.

Mutations in LRRK2 (leucine-rich repeat kinase 2) (also known as PARK8 or dardarin) are responsible for the autosomal-dominant form of PD (Parkinson's disease). LRRK2 mutations were found in approximately 3-5% of familial and 1-3% of sporadic PD cases with the highest prevalence (up to 40%) in North Africans and Ashkenazi Jews. To date, mutations in LRRK2 are a major genetic risk factor for familial and sporadic PD.