Differentiation of mesenchymal stem cells into gonad and adrenal steroidogenic cells

Exploring the distribution of polymorphism across diverse breeds Worldwide in the bovine NR5A2 gene and its correlation with number of mature follicles and corpus albicans

The Nuclear receptor subfamily 5 group A member 2 (NR5A2) gene plays a pivotal role in ovarian development, ovulation, and reproductive traits. There is a lack of studies on its impact on ovarian traits and reproductive traits in cattle. This study aimed to explore NR5A2 gene polymorphisms associations with reproductive traits and investigate the distribution of NR5A2 gene polymorphisms across diverse bovine breeds worldwide. We identified a novel 17-bp deletion within the NR5A2 gene specifically in Chinese Holstein cows (n = 1033) leading to the observation of two genotypes DD and ID. Subsequent association analysis revealed a significant correlation between the 'ID' genotype at this locus and a larger number of corpus albicans (p = 0.042) in diestrus, as well as a higher number of mature follicles (p = 0.038) in estrus. In addition, we also found that the distribution of this deletion exhibits strong regionality across different cattle breeds globally. These findings indicate that the 17-bp deletion mutation within the NR5A2 gene is significantly associated with an increased corpus luteum diameter and a greater number of mature follicles, suggesting its potential utility as a valuable DNA marker for enhancing cow fertility.

Effect of pregnancy on isolation efficiency and in vitro proliferation of equine peripheral-blood derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) have regenerative and immunomodulatory potential and may be used to treat injured tissues. Pregnancy has been associated with increased MSCs in the peripheral circulation in multiple species, but to date, there are no reports on this matter in horses. This study aimed to evaluate the effect of pregnancy on isolation efficiency and proliferation capacity of equine MSCs derived from the peripheral blood (PB) of mares. Venous blood samples were collected at the 11th month of gestation and 1 month after delivery from clinically healthy Arabian mares that presented normal pregnancies. Blood samples were processed for in vitro cellular culture and hormonal and metabolic profiles. MSCs were isolated and characterized by trilineage differentiation potential, immunophenotyping, analyzed by gene sequencing and proliferation assays. The isolation of peripheral blood mononuclear cells (PBMCs) of pregnant mares were associated with higher isolation efficiency and proliferative capacity of MSCs derived from peripheral blood (PB-MSCs) recovered pre-partum than those isolated post-partum. Although fetal gender, parity, 5α-reduced pregnanes, insulin, and cortisol were shown to affect cellular proliferation, individual factors and the small population studied must be considered. This study suggests that PB-MSCs from pregnant mares could be a valuable alternative source of MSCs for therapeutic purposes.

Dynamics of Sex Hormones in Men with Diabetes Mellitus After Autologous Mesenchymal Stem Cell Transplant

OBJECTIVES

Our goal was to determine levels of sex hormones in men with type 1 diabetes mellitus and type 2 diabetes mellitus after autologous mesenchymal stem cell transplant.

MATERIALS AND METHODS

We examined 10 male patients (32-56 years old) with type 1 diabetes mellitus and type 2 diabetes mellitus, whom we subsequently divided into 2 groups and examined. Group 1 comprised 5 male patients who received autologous mesenchymal stem cell transplant (cells were obtained from patient's iliac crest and cultured for 3-4 weeks) by intravenous infusion. Group 2 comprised 5 male patients (control group) who were on hypoglycemic tablet therapy or insulin therapy. The quantity of autologous mesenchymal stem cells infused was 95 × 106 to 97 × 106 cells. We analyzed levels of testosterone, luteinizing hormone, estradiol, and glycated hemoglobin in patients both before and 3 months after the autologous mesenchymal stem cell transplant procedure.

RESULTS

In men with type 1 diabetes mellitus and type 2 diabetes mellitus, autologous mesenchymal stem cell transplant led to an increase in testosterone levels from 5.31 ± 2.12 to 6.33 ± 2.12 ng/mL (P = .82), a decrease in luteinizing hormone from 8.43 ± 1.25 to 5.94 ± 1.57 mIU/mL (P = .04), and a decrease in glycated hemoglobin from 9.45 ± 1.24% to 8.53 ± 1.08% (P = .25) after 3 months. The increase in testosterone in men with autologous mesenchymal stem cell transplant group of 6.33 ± 2.12 ng/mL was significant compared with men in the control group (3.9 ± 1.18 ng/mL; P = .01).

CONCLUSIONS

Testosterone level increased and luteinizing hormone level decreased within 3 months after autologous mesenchymal stem cell transplant in men with diabetes mellitus.

Effect of vas ligation on testicular sperm extraction results in nonobstructive azoospermic rats: Shaeer's lock-in technique

This study evaluates the efficacy of vas ligation in enhancing sperm retrieval in nonobstructive azoospermia cases, by accumulating intratesticular spermatozoa. Fifty-six mature male rats with equally sized testes were included in this study. Forty-six were in the study group, and 10 were in the control group. Bilateral testicular fine needle aspiration was performed for all, to confirm presence of spermatozoa in all testes. Nonobstructive azoospermia was induced in all 56 rats, using Dienogest (40 mg/kg) + Testosterone Undecanoate (25 mg/kg) every month for three months. Monthly aspirations confirmed nonobstructive azoospermia from all rats, within the three months treatment. This was followed by unilateral vas ligation and was performed for 46 rats of the study group, with no ligation performed in the control group. After a further period of 90 days (2 spermatogenic cycles) with the same medical treatment maintained, bilateral testicular sperm extraction was performed. Sperm retrieval was evaluated, comparing the outcome of vas-ligated testicles to the nonligated. Upon evaluation, spermatozoa were found in 14/46 of the vas-ligated testes (30.4%), compared to none of the nonligated (0/66), p = .0005. Ligation of the vas deferens in rats with nonobstructive azoospermia may enhance the results of sperm retrieval via sperm accumulation.

Directing differentiation of human induced pluripotent stem cells toward androgen-producing Leydig cells rather than adrenal cells

Reduced serum testosterone (T), or hypogonadism, affects millions of men and is associated with many pathologies, including infertility, cardiovascular diseases, metabolic syndrome, and decreased libido and sexual function. Administering T-replacement therapy (TRT) reverses many of the symptoms associated with low T levels. However, TRT is linked to side effects such as infertility and increased risk of prostate cancer and cardiovascular diseases. Thus, there is a need to obtain T-producing cells that could be used to treat hypogonadism via transplantation and reestablishment of T-producing cell lineages in the body. T is synthesized by Leydig cells (LCs), proposed to derive from mesenchymal cells of mesonephric origin. Although mesenchymal cells have been successfully induced into LCs, the limited source and possible trauma to donors hinders their application to clinical therapies. Alternatively, human induced pluripotent stem cells (hiPSCs), which are expandable in culture and have the potential to differentiate into all somatic cell types, have become the emerging source of autologous cell therapies. We have successfully induced the differentiation of hiPSCs into either human Leydig-like (hLLCs) or adrenal-like cells (hALCs) using chemically defined culture conditions. Factors critical for the development of LCs were added to both culture systems. hLLCs expressed all steroidogenic genes and proteins important for T biosynthesis, synthesized T rather than cortisol, secreted steroid hormones in response to dibutyryl-cAMP and 22(R)-hydroxycholesterol, and displayed ultrastructural features resembling LCs. By contrast, hALCs synthesized cortisol rather than T. The success in generating hiPSC-derived hLLCs with broad human LC (hLC) features supports the potential for hiPSC-based hLC regeneration.

Tissue non-specific alkaline phosphatase mediates the accumulation of cholesterol esters in the murine Y1 adrenal cortex cell line

BACKGROUND

Cholesterol esters (CEs) accumulate in the cells of the adrenal cortex and are used for the synthesis of steroid hormones. The full molecular pathways involved in mediating the accumulation of CEs within the adrenal cortex are yet to be elucidated. Tissue non-specific alkaline phosphatase (TNAP) is needed for intracellular lipid accumulation of triglycerides in adipocytes and is also expressed in the cortical cells of the adrenal gland. Therefore we aimed to determine if TNAP is needed for the accumulation of CEs within the murine Y1 adrenal cortex cell line.

METHODS

Y1 cells were induced to accumulate lipids. Lipid accumulation and TNAP activity and expression were determined throughout intracellular lipid accumulation. The location of TNAP within the cell was determined through immunohistochemical analysis. Lipid accumulation in the cells was associated with a rise in TNAP activity and TNAP was localised to lipid droplets within the Y1 cells. Inhibition of TNAP with a specific inhibitor (levamisole) resulted in the cessation of CE accumulation.

DISCUSSION AND CONCLUSIONS

These data demonstrate that TNAP plays a role in the control of lipid accumulation in this adrenal cortex cell line. Therefore, in both triglyceride and CE storing cell types TNAP would seem to be essential for intra-cellular lipid storage.

Cyclooxygenase-2 is acutely induced by CCAAT/enhancer-binding protein β to produce prostaglandin E 2 and F 2α following gonadotropin stimulation in Leydig cells

Cyclooxygenase 2 (COX-2) is an inducible rate-limiting enzyme for prostanoid production. Because COX-2 represents one of the inducible genes in mouse mesenchymal stem cells upon differentiation into Leydig cells, we investigated COX-2 expression and production of prostaglandin (PG) in Leydig cells. Although COX-2 was undetectable in mouse testis, it was transiently induced in Leydig cells by human chorionic gonadotropin (hCG) administration. Consistent with the finding that Leydig cells expressed aldo-keto reductase 1B7 (PGF synthase) and PGE synthase 2, induction of COX-2 by hCG caused a marked increase in testicular PGF _2α and PGE ₂ levels. Using mouse Leydig cell tumor-derived MA-10 cells as a model, it was indicated by reporter assays and electron mobility shift assays that transcription of the COX-2 gene was activated by CCAAT/enhancer-binding protein β (C/EBPβ) with cAMP-stimulation. C/EBPβ expression was induced by cAMP-stimulation, whereas expression of C/EBP homolog protein (CHOP) was robustly downregulated. Transfection of CHOP expression plasmid inhibited cAMP-induced COX-2 promoter activity. In addition, CHOP reduced constitutive COX-2 expression in other mouse Leydig cell tumor-derived TM3 cells. These results indicate that COX-2 is induced in Leydig cells by activation of C/EBPβ via reduction of CHOP expression upon gonadotropin-stimulation to produce PGF _2α and PGE ₂ .

Transcriptional Regulation of Ovarian Steroidogenic Genes: Recent Findings Obtained from Stem Cell-Derived Steroidogenic Cells

Ovaries represent one of the primary steroidogenic organs, producing estrogen and progesterone under the regulation of gonadotropins during the estrous cycle. Gonadotropins fluctuate the expression of various steroidogenesis-related genes, such as those encoding steroidogenic enzymes, cholesterol deliverer, and electronic transporter. Steroidogenic factor-1 (SF-1)/adrenal 4-binding protein (Ad4BP)/NR5A1 and liver receptor homolog-1 (LRH-1) play important roles in these phenomena via transcriptional regulation. With the aid of cAMP, SF-1/Ad4BP and LRH-1 can induce the differentiation of stem cells into steroidogenic cells. This model is a useful tool for studying the molecular mechanisms of steroidogenesis. In this article, we will provide insight into the transcriptional regulation of steroidogenesis-related genes in ovaries that are revealed from stem cell-derived steroidogenic cells. Using the cells derived from the model, novel SF-1/Ad4BP- and LRH-1-regulated genes were identified by combined DNA microarray and promoter tiling array analyses. The interaction of SF-1/Ad4BP and LRH-1 with transcriptional regulators in the regulation of ovarian steroidogenesis was also revealed.

The Orphan Nuclear Receptors Steroidogenic Factor-1 and Liver Receptor Homolog-1: Structure, Regulation, and Essential Roles in Mammalian Reproduction

Nuclear receptors are intracellular proteins that act as transcription factors. Proteins with classic nuclear receptor domain structure lacking identified signaling ligands are designated orphan nuclear receptors. Two of these, steroidogenic factor-1 (NR5A1, also known as SF-1) and liver receptor homolog-1 (NR5A2, also known as LRH-1), bind to the same DNA sequences, with different and nonoverlapping effects on targets. Endogenous regulation of both is achieved predominantly by cofactor interactions. SF-1 is expressed primarily in steroidogenic tissues, LRH-1 in tissues of endodermal origin and the gonads. Both receptors modulate cholesterol homeostasis, steroidogenesis, tissue-specific cell proliferation, and stem cell pluripotency. LRH-1 is essential for development beyond gastrulation and SF-1 for genesis of the adrenal, sexual differentiation, and Leydig cell function. Ovary-specific depletion of SF-1 disrupts follicle development, while LRH-1 depletion prevents ovulation, cumulus expansion, and luteinization. Uterine depletion of LRH-1 compromises decidualization and pregnancy. In humans, SF-1 is present in endometriotic tissue, where it regulates estrogen synthesis. SF-1 is underexpressed in ovarian cancer cells and overexpressed in Leydig cell tumors. In breast cancer cells, proliferation, migration and invasion, and chemotherapy resistance are regulated by LRH-1. In conclusion, the NR5A orphan nuclear receptors are nonredundant factors that are crucial regulators of a panoply of biological processes, across multiple reproductive tissues.

Induction of steroidogenic cells from adult stem cells and pluripotent stem cells [Review]

Steroid hormones are mainly produced in adrenal glands and gonads. Because steroid hormones play vital roles in various physiological processes, replacement of deficient steroid hormones by hormone replacement therapy (HRT) is necessary for patients with adrenal and gonadal failure. In addition to HRT, tissue regeneration using stem cells is predicted to provide novel therapy. Among various stem cell types, mesenchymal stem cells can be differentiated into steroidogenic cells following ectopic expression of nuclear receptor (NR) 5A subfamily proteins, steroidogenic factor-1 (also known as adrenal 4 binding protein) and liver receptor homolog-1, with the aid of cAMP signaling. Conversely, these approaches cannot be applied to pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells, because of poor survival following cytotoxic expression of NR5A subfamily proteins. However, if pluripotent stem cells are first differentiated through mesenchymal lineage, they can also be differentiated into steroidogenic cells via NR5A subfamily protein expression. This approach offers a potential suitable cells for future regenerative medicine and gene therapy for diseases caused by steroidogenesis deficiencies. It represents a powerful tool to investigate the molecular mechanisms involved in steroidogenesis. This article highlights our own and current research on the induction of steroidogenic cells from various stem cells. We also discuss the future direction of their clinical application.

Stem cell therapy for the treatment of Leydig cell dysfunction in primary hypogonadism

The production of testosterone occurs within the Leydig cells of the testes. When production fails at this level from either congenital, acquired, or systemic disorders, the result is primary hypogonadism. While numerous testosterone formulations have been developed, none are yet fully capable of replicating the physiological patterns of testosterone secretion. Multiple stem cell therapies to restore androgenic function of the testes are under investigation. Leydig cells derived from bone marrow, adipose tissue, umbilical cord, and the testes have shown promise for future therapy for primary hypogonadism. In particular, the discovery and utilization of a group of progenitor stem cells within the testes, known as stem Leydig cells (SLCs), has led not only to a better understanding of testicular development, but of treatment as well. When combining this with an understanding of the mechanisms that lead to Leydig cell dysfunction, researchers and physicians will be able to develop stem cell therapies that target the specific step in the steroidogenic process that is deficient. The current preclinical studies highlight the complex nature of regenerating this steroidogenic process and the problems remain unresolved. In summary, there appears to be two current directions for stem cell therapy in male primary hypogonadism. The first method involves differentiating adult Leydig cells from stem cells of various origins from bone marrow, adipose, or embryonic sources. The second method involves isolating, identifying, and transplanting stem Leydig cells into testicular tissue. Theoretically, in-vivo re-activation of SLCs in men with primary hypogonadism due to age would be another alternative method to treat hypogonadism while eliminating the need for transplantation.

Regulation of Steroidogenesis, Development, and Cell Differentiation by Steroidogenic Factor-1 and Liver Receptor Homolog-1

Steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) belong to the nuclear receptor superfamily and are categorized as orphan receptors. In addition to other nuclear receptors, these play roles in various physiological phenomena by regulating the transcription of target genes. Both factors share very similar structures and exhibit common functions. Of these, the roles of SF-1 and LRH-1 in steroidogenesis are the most important, especially that of SF-1, which was originally discovered and named to reflect such roles. SF-1 and LRH-1 are essential for steroid hormone production in gonads and adrenal glands through the regulation of various steroidogenesis-related genes. As SF-1 is also necessary for the development of gonads and adrenal glands, it is also considered a master regulator of steroidogenesis. Recent studies have clearly demonstrated that LRH-1 also represents another master regulator of steroidogenesis, which similarly to SF-1, can induce differentiation of non-steroidogenic stem cells into steroidogenic cells. Here, we review the functions of both factors in these steroidogenesis-related phenomena.

Efficient labeling in vitro with non-ionic gadolinium magnetic resonance imaging contrast agent and fluorescent transfection agent in bone marrow stromal cells of neonatal rats

Although studies have been undertaken on gadolinium labeling-based molecular imaging in magnetic resonance imaging (MRI), the use of non-ionic gadolinium in the tracking of stem cells remains uncommon. To investigate the efficiency in tracking of stem cells with non-ionic gadolinium as an MRI contrast agent, a rhodamine-conjugated fluorescent reagent was used to label bone marrow stromal cells (BMSCs) of neonatal rats in vitro, and MRI scanning was undertaken. The fluorescent-conjugated cell uptake reagents were able to deliver gadodiamide into BMSCs, and cell uptake was verified using flow cytometry. In addition, the labeled stem cells with paramagnetic contrast medium remained detectable by an MRI monitor for a minimum of 28 days. The present study suggested that this method can be applied efficiently and safely for the labeling and tracking of bone marrow stromal cells in neonatal rats.