Peritubular Cells Research Articles

Using 2-Photon Microscopy to Quantify the Effects of Chronic Unilateral Ureteral Obstruction on Glomerular Processes

Applying novel microscopy methods to suitable animal disease models to explore the dynamic physiology of the kidney remains a challenge. Rats with surface glomeruli provide a unique opportunity to investigate physiological and pathophysiological processes using intravital 2-photon microscopy. Quantification of glomerular capillary blood flow and vasoconstriction and dilatation in response to drugs, permeability, and inflammation are just some of the processes that can be studied. In addition, transgenic rats, i.e., podocytes labeled with fluorescent dyes and other molecular biomarker approaches, provide increased resolution to directly monitor and quantify protein-protein interactions and the effects of specific molecular alterations. In mice, which lack surface glomeruli after four weeks of age, unilateral ureteral obstruction (UUO) for several weeks has been used to induce surface glomeruli. As this induction model does not allow for baseline studies, we quantified the effects of UUO on glomerular processes in the UUO model in Munich Wistar Frömter (MWF) rats, which have surface glomeruli under physiologic conditions. The UUO model for five weeks or more induced significant alterations to gross renal morphology, the peritubular and glomerular microvasculature, as well as the structure and function of tubular epithelia. Glomerular and peritubular red blood cell (RBC) flow decreased significantly (p < 0.01), probably due to the significant increase in the adherence of white blood cells (WBCs) within glomerular and peritubular capillaries. The glomerular sieving coefficient of albumin increased from 0.015 ± 0.002 in untreated MWFs to 0.045 ± 0.05 in 5-week-old UUO MWF rats. Twelve weeks of UUO resulted in further increases in surface glomerular density and glomerular sieving coefficient (GSC) for albumin. Fluorescent albumin filtered across the glomeruli was not reabsorbed by the proximal tubules. These data suggest that using UUO to induce surface glomeruli limits the ability to study and interpret normal glomerular processes and disease alterations.

Deletion of NFIX results in defective progression through meiosis within the mouse testis†.

Members of the nuclear factor I (NFI) family are key regulators of stem cell biology during development, with well-documented roles for NFIA, NFIB, and NFIX in a variety of developing tissues, including brain, muscle, and lung. Given the central role these factors play in stem cell biology, we posited that they may be pivotal for spermatogonial stem cells or further developing spermatogonia during testicular development. Surprisingly, in stark contrast to other developing organ systems where NFI members are co-expressed, these NFI family members show discrete patterns of expression within the seminiferous tubules. Sertoli cells (spermatogenic supporting cells) express NFIA, spermatocytes express NFIX, round spermatids express NFIB, and peritubular myoid cells express each of these three family members. Further analysis of NFIX expression during the cycle of the seminiferous epithelium revealed expression not in spermatogonia, as we anticipated, but in spermatocytes. These data suggested a potential role for NFIX in spermatogenesis. To investigate, we analyzed mice with constitutive deletion of Nfix (Nfix-null). Assessment of germ cells in the postnatal day 20 (P20) testes of Nfix-null mice revealed that spermatocytes initiate meiosis, but zygotene stage spermatocytes display structural defects in the synaptonemal complex, and increased instances of unrepaired DNA double-strand breaks. Many developing spermatocytes in the Nfix-null testis exhibited multinucleation. As a result of these defects, spermatogenesis is blocked at early diplotene and very few round spermatids are produced. Collectively, these novel data establish the global requirement for NFIX in correct meiotic progression during the first wave of spermatogenesis.

The potential adverse effect of 2.45 GHz microwave radiation on the testes of prenatally exposed peripubertal male rats.

In utero development of organs is easily influenced by many environmental factors. The aim of this study was to elucidate the effect of microwave radiation (MR) at a frequency of 2.45 GHz and a specific absorption rate of 1.73 W/kg on intrauterine development of testis. Pregnant albino rats were exposed to whole-body MR for 2 hours per day throughout the pregnancy. Male offspring (n=12, age 35 days) were not exposed to MR after birth. The study revealed that MR applied in utero induced apparent structural changes in the testes, such as irregular shape of seminiferous tubules, significant decrease in the diameter of seminiferous tubules (p<0.05) and in the height of the germinal epithelium (p<0.01), disorganisation of germ cells, desquamations of immature germ cells, formation of giant multinucleated cells, and significant (p<0.01) expansion of the interstitium. At the level of transmission electron microscopy, there were observed basement membrane irregularities in seminiferous tubules, vacuolation of the cytoplasm and adversely affected organelles in Sertoli cells, germ cells, Leydig cells, peritubular and endothelial cells. The tight junctions between adjacent Sertoli cells were often incomplete, and necrotizing germ cells were more numerous in experimental animals compared to controls. Enhanced necrotizations of germ cells proved by a Fluoro Jade C method, and declined germ cells proliferation confirmed by proliferating cell nuclear antigen analysis, were detected in MR exposed animals. Our results revealed that the prenatal exposure to MR had an adverse effect on the postnatal testicular development in rats.

Leptin secreted from testicular microenvironment modulates hedgehog signaling to augment the endogenous function of Leydig cells

Although testosterone deficiency (TD) may be present in one out of five men 40 years or older, the factors responsible for TD remain largely unknown. Leydig stem cells (LSCs) differentiate into adult Leydig cells (ALC) and produce testosterone in the testes under the pulsatile control of luteinizing hormone (LH) from the pituitary gland. However, recent studies have suggested that the testicular microenvironment (TME), which is comprised of Sertoli and peritubular myoid cells (PMC), plays an instrumental role in LSC differentiation and testosterone production under the regulation of the desert hedgehog signaling pathway (DHH). It was hypothesized that the TME releases paracrine factors to modulate LSC differentiation. For this purpose, cells (Sertoli, PMCs, LSCs, and ALCs) were extracted from men undergoing testis biopsies for sperm retrieval and were evaluated for the paracrine factors in the presence or absence of the TME (Sertoli and PMC). The results demonstrated that TME secretes leptin, which induces LSC differentiation and increases testosterone production. Leptin’s effects on LSC differentiation and testosterone production, however, are inversely concentration-dependent: positive at low doses and negative at higher doses. Mechanistically, leptin binds to the leptin receptor on LSCs and induces DHH signaling to modulate LSC differentiation. Leptin-DHH regulation functions unidirectionally insofar as DHH gain or loss of function has no effect on leptin levels. Taken together, these findings identify leptin as a key paracrine factor released by cells within the TME that modulates LSC differentiation and testosterone release from mature Leydig cells, a finding with important clinical implications for TD.

Expression of oxytocin receptors and oxytocin assisted electroejaculation in the domestic cat (Felis catus).

Oxytocin is a peptide hormone that mainly functions to control the contractility of smooth muscles and sex-related steroidogenesis in male reproductive tracts. However, specific information concerning this hormone in controlling the reproductive organs of cats is limited. This study aimed to investigate the expression of oxytocin receptors (OTRs) and their signal mediator via prostacyclin synthase (PTGIS) in reproductive structures following oxytocin assisted electroejaculation. In Experiment 1, the testis, cauda epididymis and vas deferens from five cats were examined by immunohistochemistry and quantitative polymerase chain reaction in order to study the responses of OTR and PTGIS mRNA to oxytocin injection. Experiment 2 examined the effect of oxytocin administration prior to electroejaculation on ejaculate characteristics and sperm quality in terms of motility, viability and fertilizing ability. Immunohistochemistry revealed the expression of OTRs in Leydig's, peritubular myoid cells and some spermatogenic cells. The expression was found in the epithelium and smooth muscle of the epididymis and vas deferens. After oxytocin administration, the OTR mRNA was upregulated in the epididymis (p>.05) and vas deferens (p=.01). The expression level of PTGIS mRNA increased in the response to oxytocin treatment only for the vas deferens (p>.05). Oxytocin treatment before electroejaculation resulted in an approximately twofold increase in sperm concentration and total sperm output/ejaculate, while this intervention did not significantly affect ejaculate volume, sperm quality or fertilizing ability. This study concluded that the oxytocin cascade is locally present in the reproductive structures and plays a role in promoting sperm delivery during electroejaculation in cats.

Plasmodium falciparum Parasite Lines Expressing DC8 and Group A PfEMP1 Bind to Brain, Intestinal, and Kidney Endothelial Cells.

Cytoadhesion of Plasmodium falciparum-infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum, CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria.

Genetic inactivation of Semaphorin 3C protects mice from acute kidney injury

To guide the development of therapeutic interventions for acute kidney injury, elucidating the deleterious pathways of this global health problem is highly warranted. Emerging evidence has indicated a pivotal role of endothelial dysfunction in the etiology of this disease. We found that the class III semaphorin SEMA3C was ectopically upregulated with full length protein excreted into the blood and truncated protein secreted into the urine upon kidney injury and hypothesized a role for SEAM3C in acute kidney injury. Sema3c was genetically abrogated during acute kidney injury and subsequent kidney morphological and functional defects in two well-characterized models of acute kidney injury; warm ischemia/reperfusion and folic acid injection were analyzed. Employing a beta actin-dependent, inducible knockout of Sema3c, we demonstrate that in acute kidney injury SEMA3C promotes interstitial edema, leucocyte infiltration and tubular injury. Additionally, intravital microscopy combined with Evans Blue dye extravasation and primary culture of magnetically sorted peritubular endothelial cells identified a novel role for SEMA3C in promoting vascular permeability. Thus, our study points to microvascular permeability as an important driver of injury in acute kidney injury, and to SEMA3C as a novel permeability factor and potential target for therapeutic intervention.

Leukemia inhibitory factor-receptor signalling negatively regulates gonadotrophin-stimulated testosterone production in mouse Leydig Cells

Testicular Leydig cells (LCs) are the principal source of circulating testosterone in males. LC steroidogenesis maintains sexual function, fertility and general health, and is influenced by various paracrine factors. The leukemia inhibitory factor receptor (LIFR) is expressed in the testis and activated by different ligands, including leukemia inhibitory factor (LIF), produced by peritubular myoid cells. LIF can modulate LC testosterone production in vitro under certain circumstances, but the role of consolidated signalling through LIFR in adult LC function in vivo has not been established. We used a conditional Lifr allele in combination with adenoviral vectors expressing Cre-recombinase to generate an acute model of LC Lifr-KO in the adult mouse testis, and showed that LC Lifr is not required for short term LC survival or basal steroidogenesis. However, LIFR-signalling negatively regulates steroidogenic enzyme expression and maximal gonadotrophin-stimulated testosterone biosynthesis, expanding our understanding of the intricate regulation of LC steroidogenic function.

Dynamic Expression of the Homeobox Factor PBX1 during Mouse Testis Development

Members of the pre-B-cell leukemia transcription factor (PBX) family of homeoproteins are mainly known for their involvement in hematopoietic cell differentiation and in the development of leukemia. The four PBX proteins, PBX1, PBX2, PBX3 and PBX4, belong to the three amino acid loop extension (TALE) superfamily of homeoproteins which are important transcriptional cofactors in several developmental processes involving homeobox (HOX) factors. Mutations in the human PBX1 gene are responsible for cases of gonadal dysgenesis with absence of male sex differentiation while Pbx1 inactivation in the mouse causes a failure in Leydig cell differentiation and function. However, no data is available regarding the expression profile of this transcription factor in the testis. To fill this knowledge gap, we have characterized PBX1 expression during mouse testicular development. Real time PCRs and Western blots confirmed the presence Pbx1 mRNA and PBX1 protein in different Leydig and Sertoli cell lines. The cellular localization of the PBX1 protein was determined by immunohistochemistry and immunofluorescence on mouse testis sections at different embryonic and postnatal developmental stages. PBX1 was detected in interstitial cells and in peritubular myoid cells from embryonic life until puberty. Most interstitial cells expressing PBX1 do not express the Leydig cell marker CYP17A1, indicating that they are not differentiated and steroidogenically active Leydig cells. In adults, PBX1 was mainly detected in Sertoli cells. The presence of PBX1 in different somatic cell populations during testicular development further supports a direct role for this transcription factor in testis cell differentiation and in male reproductive function.

Expression of the NSE,SP,NFH and DβH in normal and cryptorchid testes of Bactrian camel.

Neuroendocrine substances play essential roles in regulating the normal physiological functions of testicles. The purpose of this study is to explore the localization and effects of four neuroendocrine markers (NSE, SP, NFH and DβH) in normal and cryptorchid testes of Bactrian camels using western blotting, transmission electron microscopy, immunohistochemistry, and immunofluorescence methods. The results showed that cryptorchidism caused a reduction in layers of spermatogenic epithelium and decreased glycogen positivity in the basement membrane. The ultrastructure revealed that macrophages were always found around the Leydig cells, crowded with swelling mitochondria in cryptorchidism. Expression of NSE in the Leydig cells of cryptorchidism was significantly weakened compared to that in the normal group(p<0.01). We found that SP was always distributed along the nerve fibers in normal testes and was expressed in the Leydig cells of cryptorchidism. However, expression of NFH in the cryptorchidic tissue was strongly positive in the spermatogenic epithelium, with limited expression in Leydig cells and no expression in peritubular myoid cells. Therefore, the expression of DβH in the Sertoli cells was comparatively strong in both the normal and cryptorchidism groups. NFH and DβH expression was significantly increased in the cryptorchidism group compared with the normal group (p<0.01). These findings indicated that the underdeveloped seminiferous epithelium and pathological changes in cryptorchid tissue in Bactrian camels were potentially related to a disorder in glycoprotein metabolism. Our results suggest that NSE and SP could help judge the pathological changes of cryptorchidism. The present study provides the first evidence at the protein level for the existence of NFH and DβH in Sertoli and Leydig cells in Bactrian camel cryptorchidism and provides a more in-depth understanding of neuroendocrine regulation is crucial for animal cryptorchidism.

Blood Count Under the Effect of Erythropoietin (EPO) in Patients with Chronic Hemodialysis

One of the most common associated diseases in dialysis patients is anemia. The number of erythrocytes, hemoglobin and hematocrit is reduced in patients that suffer from anemia. These three measurement parameters represent the most important "red part" of the blood count. Due to renal insufficiency, patients on hemodialysis do not have enough erythropoietin, which healthy kidneys excreted, and is necessary for hematopoiesis. Erythropoietin (EPO) is the main regulator of the daily production of red blood cells. EPO that is execrated by peritubular capillary membrane cells in the kidneys circulates within plasma in order to interact with target cells in the bone marrow to maintain or stimulate erythropoiesis. The main purpose of the action of EPO is the formation of erythroid colonies. During observation of differences in the ordination of EPO in each group between men and women, there is no statistical significance evident in the incidence of anemia before and after therapy, as in p=0.70. The target concentration of hemoglobin, which must be constantly maintained in people with chronic renal anemia, is 110-120 g/l, while the target value of the number of red blood cells is 4-5x10¹²/l and the hematocrit value is 0.35-4.5 l/l, with a slight outflow depending on the gender of the patient. The final values of the participants in our study treated with epoetin alpha show higher values of hemoglobin, hematocrit and erythrocytes, while the average values recorded in participants treated with darbepoetin decreased.

Immunoexpression of androgen receptor in genital tissues of male BALB/c mice

Aim: Androgens are hormones that are essential for the differentiation and development of male genital organs, preserving their structural features and maintaining their functions. These hormones exert their effects on target tissues mainly through androgen receptors (AR). The aim of this study was to determine the AR immunoexpression pattern in the genital tissues of male mice. Materials and Methods: A total of 6 BALB/c male mice were anesthetized with ether, and the genital tissues, which were quickly removed from the body, were fixed in Bouin’s solution for 18 hours. Tissues that underwent routine histological procedures after fixation were embedded in paraffin. Tissue sections cut with a thickness of 5 µm from paraffin blocks were taken on a slide and examined by staining with immunohistochemical methods. Results: AR-positive immunostaining in the testis was observed only in somatic cells such as Sertoli, peritubular myoid cells, and Leydig cells. Germ cells were AR-negative. In the caput epididymis, ductus deferens, and seminal vesicle, AR positive immunoexpression was observed in stromal cells, especially epithelial cells. Although AR-positive staining was observed in some of the epithelial and stromal cells in these organs, some of them were AR-negative. Conclusion: In the current study, it was determined that the AR expression pattern in the genital tissues of male BALB/c mice was similar to that in other species, although there were minor differences. The findings support the hypothesis that androgens exert their effects in testis mainly through somatic cells, and their effects in other genital tissues through epithelial cells, and the fact that androgens/ARs are essential for maintaining the structures and functions of male genital organs.

A model to study human ovotesticular syndrome

Ovotesticular syndrome is a rare disorder of sex development characterized by the presence of testicular and ovarian tissue. The histologic characteristics of human testicular tissue are well defined by the presence of seminiferous cords or tubules containing TSPY-positive germ cells and Sox9-positive Sertoli cells surrounded by interstitial tissue containing cytochrome P450-positive Leydig cells and smooth muscle α-actin-positive peritubular myoid cells. The histological characteristics of the ovary can be defined by germ cell nests and the development of follicles. In contrast to the testis, the ovary has a paucity of defined specific protein markers, with the granulosa cell marker FOXL2 being the most widely used. In practice, defining the ovarian component of the ovotestis can be quite difficult.We developed a model of human ovotesticular syndrome by combining fetal human testis and ovary in a xenograft model. Ovotesticular xenografts were grown under the renal capsules of gonadectomized athymic nude mice for 6–32 weeks along with age matched control grafts of fetal testis and ovary. Forty ovotesticular xenografts and their controls were analyzed by histology, immunohistochemistry, and fluorescent in situ hybridization to determine the protein expression and karyotype of the cells within the grafts.The ovotesticular xenografts exhibited recognizable testicular and ovarian tissue based on testis-specific and ovary-specific markers defined above. The xenografts simulated a bipolar ovotestis in which the testicular and ovarian elements retain their separate histological characteristics and are separated by a well-defined border. This contrasts with the compartmentalized ovotestis previously described in the literature where the testicular tissue is surrounded by ovarian tissue or a mixed histology where testicular and ovarian tissues are interspersed throughout the gonad.In conclusion, we have characterized a human model of ovotestis which will allow a deeper understanding of ovotestis development in humans and facilitate a more accurate diagnosis of the ovotesticular syndrome.

Immunoregulation in the testis and its implication in fertility and infections

The testis is designated as one of the immune previleged sites in the body and harbours a unique immunoregulatory environment, which is important for preventing an immune response against sperm antigens which otherwise are recognized as “foreign” by the immune system. The blood-testis barrier along with the unique immune cells repertoire and various immunoregulatory &amp; immunosuppressive factors secreted by the Leydig cells, Sertoli cells and peritubular cells act in concert to maintain the tolerogenic environment in the testis. Abberations in immunotolerant mechanisms in the testis can lead to generation of anti-sperm antibodies that have an association with male infertility. It can also lead to inflammatory conditions of the male reproductive tract manifested as epididymitis and orchitis, generally due to bacterial or viral infections. In addition, non-infectious epididymitis and orchitis, having autoimmune origin have also been reported in males. While the immune privilege status of human testis protects the germ cells from an immune attack, it can also make the testis a succeptible reservoir for viruses such as human immunodeficiency virus-1, Zika virus and severe acute respiratory syndrome coronavirus-2, all of which have adverse consequences on male reproduction.

Detection and localization of atypical porcine pestivirus in the testicles of naturally infected, congenital tremor affected piglets.

Atypical porcine pestivirus (APPV) belongs to the genus Pestivirus within the family Flaviviridae. Recently, APPV has been identified as the causative agent of congenital tremor (CT) type AII. The disease is a neurological disorder that affects newborn piglets and is characterized by generalized trembling of the animals and often splay legs. CT is well known worldwide, and the virus seems to be highly prevalent in major swine producing areas. However, little is known about the epidemiology of the infection, transmission and spread of the virus between herds. Here, we show the high prevalence of APPV in processing fluid samples collected from Hungarian pig herds which led us to investigate the cellular targets of the virus in the testicles of newborn piglets affected by CT. By the development of an RNA in situ hybridization assay and the use of immunohistochemistry on consecutive slides, we identified the target cells of APPV in the testicle: interstitial Leydig cells, peritubular myoid cells and smooth muscle cells of medium‐sized arteries. Previous studies have shown that APPV can be found in the semen of sexually mature boars suggesting the role of infected boars and their semen in the transmission of the virus similar to many other members of the Flaviviridae family. As in our case, the virus has not been identified in cells beyond the Sertoli cell barrier, further studies on infected adult boars’ testicles and other reproductive glands are needed to analyze the possible changes in the cell tropism of APPV that might contribute to its prolonged extraction by the semen beyond the period of viraemia.

Valproic acid during pregnancy decrease the number of spermatogenic cells and testicular volume in the offspring of mice: Stereological quantification.

Valproic acid (VPA) is a drug used to treat epilepsy, bipolar disorders and headaches. As a secondary effect, this antiepileptic drug can cause a decrease in androgens and gonadotropins, and dose-dependent testicular defects, such as reduction of testicular weights, sperm motility and degeneration of the seminiferous tubules. In offspring exposed to VPA, its effects have not been evaluated, so the study aimed to determine the morphological effects of the use of VPA along testicular development in mice. 30 adult female BALB/c mice were crossed and divided by age, with embryos of 12.5 days post coitum (dpc), fetuses of 17.5 dpc and male mice 6 weeks postnatal. In each case, the pregnant mouse received 600 mg/kg of VPA, making up the VPA groups, or 0.3 mL of 0.9% physiological solution for the control groups, from the beginning to the end of the pregnancy, orally.t. A morpho-quantitative analysis was carried out on the gonadal development of the male offspring. In the groups treated with VPA, at all ages studied they had lower testicular volume. At 12.5 dpc, they showed less testicular development in the form of sex cords, with fewer gonocytes and somatic cells. At 17.5 dpc, they presented greater interstitial space, fewer spermatogonial, sustentacular Sertoli, peritubular and interstitial Leydig cells. At 6 weeks postnatal, they presented fewer spermatogonia, pachytene spermatocytes, elongated spermatids, sustentacular Sertoli and interstitial Leydig cells, with statistically significant differences. In conclusion, prenatal exposure to VPA causes histopathological alterations in the offspring of mice in testicular development, from the embryonic stage to 6 weeks postnatal.

WITHDRAWN: Distribution of the Novel RFRP-3/receptors system in the epididymis of the seasonal desert rodent, Gerbillus tarabuli, during sexual activity

RFamide-related peptide (RFRP-3), the Mammalian ortholog of the Avian gonadotropin-inhibitory hormone (GnIH), is a novel neuropeptide known for its inhibitory regulatory effect on reproduction in various mammalian species. However, a stimulatory action has been reported. This paper aims to: i) study the histology of the epididymis (caput) of Gerbillus tarabuli during the breeding period; and ii) to determine the distribution of the “RFRP-3/receptors system” in the epididymis (caput) of this desert rodent during the active season, and thus, to inspect its potential local interfering in sperm maturation. For that, immunohistochemistry was performed to detect the epididymal immunolocalizations of the three molecules, RFRP-3, GPR147, and GPR74. This is the first report of the epididymis histology in Gerbillus tarabuli, as it is the first evidence of the existence of the RFRP-3/Receptor system in the same organ of the same species. During the breeding season, moderate immunostaining of the RFRP-3/receptors system was present in the caput epididymis’ epithelial parts (basal and principal cells) and spermatozoa. In contrast, these three molecules were absent in the peritubular and muscle coat's myoid cells and of the interstitial part of the caput epididymis. The results suggest that the epididymis is a potential source of RFRP-3 in the desert Rodent, Gerbillus tarabuli, which may function as a paracrine and/or autocrine factor affecting the main epididymis’ function: sperm maturation.

An Improved Protocol for the Isolation and Monoculture of Primary Murine Renal Peritubular Endothelial Cells to Enhance Long-Term Phenotypic Retention

An Improved Protocol for the Isolation and Monoculture of Primary Murine Renal Peritubular Endothelial Cells to Enhance Long-Term Phenotypic Retention

LEPTIN SECRETED FROM TESTICULAR MICROENVIRONMENT BINDS TO LEPTIN RECEPTOR ON LEYDIG CELLS AND MODULATES THEIR ENDOGENOUS FUNCTION

Leydig stem cells (LSCs) differentiate into adult Leydig cells (ALC) and produce testosterone in the testes under the pulsatile control of luteinizing hormone (LH) from the pituitary gland. However, our recent studies suggest that the testicular microenvironment (TME), which is comprised of Sertoli and peritubular myoid cells (PMC), plays an instrumental role in LSC differentiation and testosterone production under the regulation of the desert hedgehog signalling pathway (DHH). In the present study, we hypothesized that testicular TME releases paracrine factors that modulates LSC differentiation.

Aging, inflammation and DNA damage in the somatic testicular niche with idiopathic germ cell aplasia

Molecular mechanisms associated with human germ cell aplasia in infertile men remain undefined. Here we perform single-cell transcriptome profiling to highlight differentially expressed genes and pathways in each somatic cell type in testes of men with idiopathic germ cell aplasia. We identify immaturity of Leydig cells, chronic tissue inflammation, fibrosis, and senescence phenotype of the somatic cells, as well markers of chronic inflammation in the blood. We find that deregulated expression of parentally imprinted genes in myoid and immature Leydig cells, with relevant changes in the ratio of Lamin A/C transcripts and an active DNA damage response in Leydig and peritubular myoid cells are also indicative of senescence of the testicular niche. This study offers molecular insights into the pathogenesis of idiopathic germ cell aplasia.