Laminin, type IV collagen, and fibronectin in normal and cryptorchid human testes. An immunohistochemical study

Distribution of extracellular matrix related proteins in normal and cryptorchid ziwuling black goat testes

The Ziwuling black goat is an indigenously in China, their offspring are frequently affected by congenital cryptorchidism. The extracellular matrix (ECM) contains cytokines and growth factors that regulate the development of the testis, and component changes often result in pathological changes. Cryptorchidism is closely related to structural changes in ECM. In this study, the histochemical staining, immunohistochemical, immunofluorescence and Western blot combined with semi-quantitative analysis was used to describe the distribution of the important ECM components Collagen type IV (Col IV), laminin (LN)and heparan sulfate proteoglycans (HSPG) in the normal and cryptorchid testes of Ziwuling black goats. Results showed that: The histochemical staining showed that the dysplasia of seminiferous tubules and decreased number of Sertoli cells in cryptorchidism, as well as sparse collagen fiber. Meanwhile, the distribution of reticular fibers is relatively rich. Furthermore, the PAS and AB staining in the interstitial vessels and lamina propria of seminiferous tubules is weak. The immunohistochemical and immunofluorescence revealed that Col IV, LN was strongly expressed in Leydig, Sertoli cells of normal testes and moderately positive in the spermatogonia and spermatids, but HSPG was not expressed in the spermatogonia. However, cryptorchidism, the expression of Col IV, LN and HPSG in Leydig, Sertoli cells significantly decreased, as well as the expression of Col IV and LN in capillary endothelial cells, but HSPG was moderately expressed in spermatogonia. Based on these data, the underdevelopment of spermatogenic epithelium, decreased synthesis function of collagen fibers and Leydig cells develop usually in the cryptorchidism were shown to be closely related to the abnormal metabolism of Col IV and LN. The positive expressed of HSPG in the spermatogonia of cryptorchid testes is related to the compensatory development of spermatogonia.

Spermatogonia Loss Correlates with LAMA 1 Expression in Human Prepubertal Testes Stored for Fertility Preservation

Fertility preservation for male childhood cancer survivors not yet capable of producing mature spermatozoa, relies on experimental approaches such as testicular explant culture. Although the first steps in somatic maturation can be observed in human testicular explant cultures, germ cell depletion is a common obstacle. Hence, understanding the spermatogonial stem cell (SSC) niche environment and in particular, specific components such as the seminiferous basement membrane (BM) will allow progression of testicular explant cultures. Here, we revealed that the seminiferous BM is established from 6 weeks post conception with the expression of laminin alpha 1 (LAMA 1) and type IV collagen, which persist as key components throughout development. With prepubertal testicular explant culture we found that seminiferous LAMA 1 expression is disrupted and depleted with culture time correlating with germ cell loss. These findings highlight the importance of LAMA 1 for the human SSC niche and its sensitivity to culture conditions.

Generation of Organized Porcine Testicular Organoids in Solubilized Hydrogels from Decellularized Extracellular Matrix

Cryopreservation of immature testicular tissue (ITT) prior to chemo/radiotherapy is now ethically accepted and is currently the only way to preserve fertility of prepubertal boys about to undergo cancer therapies. So far, three-dimensional culture of testicular cells isolated from prepubertal human testicular tissue was neither efficient nor reproducible to obtain mature spermatozoa, and ITT transplantation is not a safe option when there is a risk of cancer cell contamination of the testis. Hence, generation of testicular organoids (TOs) after cell selection is a novel strategy aimed at restoring fertility in these patients. Here, we created TOs using hydrogels developed from decellularized porcine ITT and compared cell numbers, organization and function to TOs generated in collagen only hydrogel. Organotypic culture of porcine ITT was used as a control. Rheological and mass spectrometry analyses of both hydrogels highlighted differences in terms of extracellular matrix stiffness and composition, respectively. Sertoli cells (SCs) and germ cells (GCs) assembled into seminiferous tubule-like structures delimited by a basement membrane while Leydig cells (LCs) and peritubular cells localized outside. TOs were maintained for 45 days in culture and secreted stem cell factor and testosterone demonstrating functionality of SCs and LCs, respectively. In both TOs GC numbers decreased and SC numbers increased. However, LC numbers decreased significantly in the collagen hydrogel TOs (p < 0.05) suggesting a better preservation of growth factors within TOs developed from decellularized ITT and thus a better potential to restore the reproductive capacity.

Development of a Cytocompatible Scaffold from Pig Immature Testicular Tissue Allowing Human Sertoli Cell Attachment, Proliferation and Functionality

Cryopreservation of immature testicular tissue before chemo/radiotherapy is the only option to preserve fertility of cancer-affected prepubertal boys. To avoid reintroduction of malignant cells, development of a transplantable scaffold by decellularization of pig immature testicular tissue (ITT) able to support decontaminated testicular cells could be an option for fertility restoration in these patients. We, therefore, compared decellularization protocols to produce a cytocompatible scaffold. Fragments of ITT from 15 piglets were decellularized using three protocols: sodium dodecyl sulfate (SDS)-Triton (ST), Triton-SDS-Triton (TST) and trypsin 0.05%/ethylenediaminetetraacetic acid (EDTA) 0.02%-Triton (TET) with varying detergent concentrations. All protocols were able to lower DNA levels. Collagen retention was demonstrated in all groups except ST 1%, and a significant decrease in glycosaminoglycans was observed in the TST 1% and TET 1% groups. When Sertoli cells (SCs) were cultured with decellularized tissue, no signs of cytotoxicity were detected. A higher SC proliferation rate and greater stem cell factor secretion were observed than with SCs cultured without scaffold. ST 0.01% and TET 3% conditions offered the best compromise in terms of DNA elimination and extracellular matrix (ECM) preservation, while ensuring good attachment, proliferation and functionality of human SCs. This study demonstrates the potential of using decellularized pig ITT for human testicular tissue engineering purposes.

Effects of Elevated β-Estradiol Levels on the Functional Morphology of the Testis - New Insights

Elevated estradiol levels are correlated with male infertility. Causes of hyperestrogenism include diseases of the adrenal cortex, testis or medications affecting the hypothalamus-pituitary-gonadal axis. The aim of our study was to elucidate the effects of estradiol treatment on testicular cellular morphology and function, with reference to the treatment regimen received. Testes samples (n = 9) were obtained post-orchiectomy from male-to-female transsexuals within the age range of 26–52 years. Each patient had a minimum of 1–6 years estradiol treatment. For comparison, additional samples were obtained from microscopically unaltered testicular tissue surrounding tumors (n = 7). The tissues obtained were investigated by stereomicroscopy, histochemistry, scanning electron microscopy (SEM) and immunohistochemistry. Our studies revealed that estradiol treatment significantly decreased the diameter of the seminiferous tubules (p < 0.05) and induced fatty degeneration in the surrounding connective tissue. An increase in collagen fiber synthesis in the extracellular matrix (ECM) surrounding the seminiferous tubules was also induced. Spermatogenesis was impaired resulting in mainly spermatogonia being present. Sertoli cells revealed diminished expression of estrogen receptor alpha (ERα). Both Sertoli and Leydig cells showed morphological alterations and glycoprotein accumulations. These results demonstrate that increased estradiol levels drastically impact the human testis.

Perspectives in Pediatric Pathology, Chapter 14. Natural History of Undescended Testes

Cryptorchidism is one of the most frequent problems encountered in pediatric urology. Its causes, associated lesions, and prognosis in terms of fertility have been a source of interest and discrepancies for pediatric pathologists and urological surgeons.

Development of the follicular basement membrane during human gametogenesis and early folliculogenesis

Background

In society, there is a clear need to improve the success rate of techniques to restore fertility. Therefore a deeper knowledge of the dynamics of the complex molecular environment that regulates human gametogenesis and (early) folliculogenesis in vivo is necessary. Here, we have studied these processes focusing on the formation of the follicular basement membrane (BM) in vivo.

Results

The distribution of the main components of the extracellular matrix (ECM) collagen IV, laminin and fibronectin by week 10 of gestation (W10) in the ovarian cortex revealed the existence of ovarian cords and of a distinct mesenchymal compartment, resembling the organization in the male gonads. By W17, the first primordial follicles were assembled individually in that (cortical) mesenchymal compartment and were already encapsulated by a BM of collagen IV and laminin, but not fibronectin. In adults, in the primary and secondary follicles, collagen IV, laminin and to a lesser extent fibronectin were prominent in the follicular BM.

Conclusions

The ECM-molecular niche compartimentalizes the female gonads from the time of germ cell colonization until adulthood. This knowledge may contribute to improve methods to recreate the environment needed for successful folliculogenesis in vitro and that would benefit a large number of infertility patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12861-015-0054-0) contains supplementary material, which is available to authorized users.

Melatonin in testes of infertile men: evidence for anti-proliferative and anti-oxidant effects on local macrophage and mast cell populations

Melatonin acting through the hypothalamus and pituitary regulates testicular function. In addition, direct actions of melatonin at the testicular level have been recently suggested. We have described that melatonin inhibits androgen production in hamster Leydig cells via melatonin subtype 1a (mel1a) receptors and the local corticotrophin-releasing hormone (CRH) system. The initial events of the melatonin/CRH signalling pathway have also been established. Melatonin and all components of the melatonergic/CRH system were also detected in Leydig cells of infertile men. This study attempted to search for additional targets of melatonin in the human testis, and to investigate the effects of melatonin on proliferation and the oxidative state in these novel target cells. To this aim, evaluation of human testicular biopsies of patients suffering from hypospermatogenesis or Sertoli cell only syndrome and cell culture studies were performed. Melatonergic receptors were found in macrophages (MACs) and mast cells (MCs) of the human testis. In biopsies of patients suffering idiopathic infertility, melatonin testicular concentrations were negatively correlated with MAC number per mm(2) and TNFα, IL1β and COX2 expression, but positively correlated with the expression of the anti-oxidant enzymes SOD1, peroxiredoxin 1 and catalase. Melatonin inhibited proliferation and the expression of pro-inflammatory cytokines and cyclooxygenase 2 (COX2) in both the human non-testicular THP-1 MAC cell line and primary cell cultures of hamster testicular MACs. In the human HMC-1 MC line, melatonin increased the expression of anti-oxidant enzymes and decreased reactive oxygen species (ROS) generation. The results reveal new testicular targets of melatonin and describe anti-proliferative and anti-inflammatory effects of this hormone on testicular MACs. Furthermore, melatonin might provide protective effects against oxidative stress in testicular MCs.

High levels of the extracellular matrix proteoglycan decorin are associated with inhibition of testicular function

Decorin (DCN), a component of the extracellular matrix of the peritubular wall and the interstitial areas of the human testis, can interact with growth factor (GF) signalling, thereby blocking downstream actions of GFs. In the present study the expression and regulation of DCN using both human testes and two experimental animal models, namely the rhesus monkey and mouse, were examined. DCN protein was present in peritubular and interstitial areas of adult human and monkey testes, while it was almost undetectable in adult wild type mice. Interestingly, the levels and sites of testicular DCN expression in the monkeys were inversely correlated with testicular maturation markers. A strong DCN expression associated with the abundant connective tissue of the interstitial areas in the postnatal through pre-pubertal phases was observed. In adult and old monkeys the DCN pattern was similar to the one in normal human testes, presenting strong expression at the peritubular region. In the testes of both infertile men and in a mouse model of inflammation associated infertility (aromatase-overexpressing transgenic mice), the fibrotic changes and increased numbers of tumour necrosis factor (TNF)-α-producing immune cells were shown to be associated with increased production of DCN. Furthermore, studies with human testicular peritubular cells isolated from fibrotic testis indicated that TNF-α significantly increased DCN production. The data, thus, show that an increased DCN level is associated with impaired testicular function, supporting our hypothesis that DCN interferes with paracrine signalling of the testis in health and disease.

Comparative expression of laminin and smooth muscle actin in the testis and epididymis of poultry and rabbit

The present investigation was conducted to demonstrate laminin and alpha smooth muscle actin (alphaSMA) in the testis and epididymis of adult chickens, Sudani ducks, pigeons, and rabbits. This study may represent the first indication for the presence of laminin in the male reproductive organs of birds and rabbits and might therefore serve as a milestone for further reports. In the testis of chicken, Sudani duck, pigeon, and rabbit, the laminin was localized in the basal lamina of the seminiferous tubules and of the peritubular myoid cells, in the testicular capsule and to a small extent in the vicinity of Leydig cells. The testicular vasculature also exhibited intense laminin immunostaining. Weak laminin staining was additionally seen in the cytoplasm of the duck Sertoli cells. In the epididymis, the basal lamina of the epididymal epithelium showed a distinctly positive reaction in all birds and rabbit. The basal lamina of the periductal myoid cells also showed a positive reaction. In the interductal tissue, laminin immunostaining was particularly observed in chicken, duck and pigeon. Laminin positive reaction was also seen in the epididymal vasculatures of all birds and rabbit. Interestingly, weak to moderate laminin staining was observed in the apical surface of the ciliated cells of the proximal and distal efferent ductules in chicken, duck and pigeon. alphaSMA positive reaction was seen in the testicular capsule and in the peritubular myoid cells of all birds and rabbit. In the testicular capsule, alphaSMA staining was either observed in the inner portion (chicken) or throughout the tunica albuginea (Sudani duck and pigeon), or in the outer aspect (rabbit). Distinct alphaSMA reaction was additionally observed in the testicular vasculature. In the epididymis of all birds and rabbit, the alphaSMA was particularly seen in the periductal and interductal myoid cells as well as in the epididymal vasculatures. No alphaSMA specific staining was however detected in the epididymal epithelium, fibrous lamina propria, and luminal spermatozoa of all birds and rabbits. In conclusion, the distribution of laminin and alphaSMA in the testis and epididymis might point out to their roles in the male reproduction.

Characterization and distribution of hyaluronan and the proteoglycans decorin, biglycan and perlecan in the developing embryonic mouse gonad

The morphogenesis of tissues and organs requires dynamic changes in cells and in extracellular matrix components. It is known that various extracellular matrix molecules are of fundamental importance for gonad differentiation and growth. In the adult testis, the extracellular matrix represents an important component of the interstitium, participating in the transport of biologically active substances needed for the communication between different cellular components, as well as for the regulation of spermatogenesis and hormone production. The present study was designed in order to identify the proteoglycans biglycan, decorin and perlecan, as well as the glycosaminoglycan hyaluronan, during testis development in mouse embryos. Our data profile the chronology of testis differentiation, as well as the distribution of these extracellular matrix components during testis development in mice. We show that these extracellular matrix molecules are present early in the development of the gonads, suggesting that they play a role in gonad development. In addition, we found no decorin in the testicular cords. Furthermore, of the proteoglycans analysed, only biglycan was seen surrounding immature Sertoli cells and Leydig cell precursors in the testicular cords. This indicates that specific sets of extracellular matrix molecules are required in the various compartments of the developing gonad.

Examination of basement membrane components associated with the bovine seminiferous tubule basal lamina

Immunohistology has been used to examine the distribution of certain components of the basement membrane (BM) associated with bovine spermatogonial germ cells that are located within the seminiferous tubules. Histology was performed on testis tissue from Brahman cattle (Bos indicus) of three different age groups: pre-pubescent (4–6 months), juvenile (8–10 months) and adult (18–24 months) animals. There were no major changes in the BM composition apparent between these three age groups, except for certain lectin staining. These data suggest that the predominant collagen type IV component may have an α3 and α4 composition, although other chains, including the α5 and α6 chains, were also present. Possibly the main laminin type present was laminin 121 (α1β2γ1), although other variants were also present. Both nidogen-1 and perlecan, which are normal BM components, were also found as part of the seminiferous tubule BM. Interstitial collagens, such as type I, III and VI collagens, were found in the peritubular space, but were not part of the BM itself, although type VI collagen was most visible in the peritubular zone adjacent to the tubules. Examination of the BM with a range of lectins gave strong staining for (glcNAc)2 entities, weak positive staining for α-l-fuc, but little or no staining for α-galNAc and (glcNAc)3 at all ages, whereas staining for α-gal, β-gal(1→3)galNAc and α-man showed developmental changes.

Assessment of seminal plasma laminin in fertile and infertile men

AIM

To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume.

METHODS

One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination: fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia (NOA), obstructive azoospermia (OA) and congenital bilateral absent vas deferens (CBAVD). The patients' medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay.

RESULTS

Seminal plasma laminin levels of successive groups were: 2.82 +/- 0.62, 2.49 +/- 0.44, 1.77 +/- 0.56, 1.72 +/- 0.76, 1.35 +/- 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups (P<0.05). Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration (r = 0.460, P < 0.001) and nonsignificant correlation with age (r = 0.021, P = 0.940), sperm motility percentage (r = 0.142, P = 0.615) and semen volume (r = 0.035, P = 0.087).

CONCLUSION

Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility.

Laminin alpha 3 forms a complex with beta3 and gamma3 chains that serves as the ligand for alpha 6beta1-integrin at the apical ectoplasmic specialization in adult rat testes

Apical ectoplasmic specialization (ES) is a testis-specific hybrid cell/cell actin-based adherens junction and cell/matrix focal contact anchoring junction type restricted to the interface between Sertoli cells and developing spermatids. Recent studies have shown that laminin gamma3, restricted to elongating spermatids, is a putative binding partner of alpha 6beta 1-integrin localized in Sertoli cells at the apical ES. However, the identity of the alpha and beta chains, which constitute a functional laminin ligand with the gamma3 chain at the apical ES, is not known. Using reverse transcription-PCR and immunoblotting to survey all laminin chains in cells of the seminiferous epithelium, it was noted that alpha 2, alpha 3, beta1, beta2, beta3, and gamma3 chains were found in germ cells, whereas alpha 1, alpha 2, alpha 4, alpha 5, beta1, beta2, gamma1, gamma2, and gamma3 chains were found in Sertoli cells, implying that alpha 3 and beta3 are the plausible laminin chains restricted to germ cells that may be the bona fide partners of gamma3. To verify this postulate, recombinant proteins based on domain G of alpha 3 and domain I of beta3 and gamma3 chains were produced and used to obtain the corresponding specific polyclonal antibodies. Additional studies have demonstrated that the laminin alpha 3, beta3, and gamma3 chains indeed are restricted to germ cells at the apical ES, co-localizing with each other and with beta1-integrin. Furthermore, co-immunoprecipitation studies have confirmed the interactions among laminin alpha 3, beta3, and gamma3, as well as beta1-integrin. When the functional laminin ligand at the apical ES was disrupted via blocking antibodies, such as using anti-laminin alpha 3 or gamma3 IgG, this treatment perturbed adhesion between Sertoli and germ cells (mostly spermatids), leading to germ cell loss from the epithelium. More important, a transient disruption of the blood-testis barrier was also detected.

Stereological and morphometric analysis of collagen and seminiferous tubules in testes of patients with cryptorchidism submitted or not to treatment with human chorionic gonadotrophin

OBJECTIVES

Quantify the distribution of collagen and analyze the seminiferous tubules diameter in the testis of patients with cryptorchidism, to verify if the previous use of human chorionic gonadotrophin (hCG) affects these structures.

MATERIAL AND METHODS

Samples of parenchymal tissue of cryptorchid testis obtained during peroperative biopsies were collected from 26 patients. Sixteen samples were embedded in paraffin and stained with picrosirius red to evidence fibers of collagen system. The quantification of these fibers was determined by stereological methods, using a test system M-42. To obtain seminiferous tubules diameter we used 10 of the 26 samples. These samples were embedded in Epon and the analyses were carried out in semi-thin sections, stained with toluidin blue. The selected results of each group were statistically analyzed and compared by the student's t and Tukey-Kramer's tests.

RESULTS

The testicular interstitium and lamina propria of patients treated with hCG showed statistically significant less collagen system fibers, when compared to the testes of patients nontreated (0.30% versus 0.39%, p = 0.0079). The seminiferous tubules diameters were not statistically significant different between the testes of patients treated and nontreated with hCG (67.5 versus 59.35 microm, p = 0.0609).

CONCLUSIONS

hCG use in the cryptorchidism could delay, at least temporarily, a progressive growth of fibers of collagen system. We did not find statistically significant difference in the seminiferous tubular diameters between treated and nontreated patients.

Sertoli cell nodules in the undescended testis: a histochemical, immunohistochemical, and ultrastructural study of hyaline deposits

AIMS

To document the morphology, immunohistochemical staining properties, and ultrastructural features of hyaline material in Sertoli cell nodules of undescended testis and contrast them with those of sex cord tumour with annular tubules (SCTAT), which is histologically similar. To highlight the need to distinguish these nodules from other Sertoli cell hyperplasias, such as intratubular Sertoli cell proliferations, which occur in specific clinical contexts.

MATERIALS/METHODS

A retrospective study of 46 orchidectomy specimens from cryptorchid testes, 27 of which contained Sertoli cell nodules. Special histochemical stains, immunohistochemical stains for type IV collagen and fibronectin, and ultrastructural examination of the hyaline material were performed using tissue from paraffin wax embedded tissue blocks.

RESULTS

The hyaline deposits in SCTAT and Sertoli cell nodules had similar staining patterns-periodic acid Schiff (PAS) and PAS-diastase positivity with variable staining of Martius scarlet blue and Masson trichrome. Type IV collagen immunoreactivity was seen in hyaline areas, although fibronectin was negative. Electron microscopy of hyaline areas confirmed a compact matrix identical to components of the basement membrane in the adjacent seminiferous tubules.

CONCLUSION

This study describes an unusual form of Sertoli cell proliferation in undescended testes, which must be distinguished from Sertoli cell tumours and other forms of proliferation. In addition, the hyaline material within Sertoli cell nodules in the cryptorchid testis is histochemically, immunohistochemically, and ultrastructurally consistent with both matrix and fibrous components of seminiferous tubule basement membranes. Increased production of basement membrane material, with subsequent invagination into tubules, is the most likely origin of this material.

From carcinoma in situ to testicular germ cell tumour

The mechanisms of invasive tumour development from pre-invasive CIS are unknown. We examined changes in functional parameters of the tubular wall according to the increase in CIS cells and tubular size. Immunohistochemistry was performed on 37 testicular specimens from 25 patients with carcinoma in situ and/or malignant germ cell tumour for the detection of actin/myosin in myocytes, and laminin/integrin alpha 6 in the basement membrane of seminiferous tubules. Tumour cells were detected by PlAP, Sertoli cells by inhibin alpha and vimentin and by cytokeratin 18/connexin 26 immunoreactivity, which is selectively expressed together with CIS. Areas showing clusters of tumour cells surrounded by a fibrous sheet could be identified as enlarged tubules because of focal Sertoli cell-specific co-expression of inhibin alpha, vimentin, cytokeratin 18, and connexin 26 immunoreaction. These clusters exhibited an intact basement membrane shown by a persistent laminin/integrin alpha 6 immunoreactivity, but myocytes had lost their contractility indicated by the loss of myosin/actin immunoreactivity. They often showed septa originating from the fibrous sheet containing numerous capillaries. Focal areas of syncytiotrophoblastic cells within classical seminoma also expressing inhibin alpha, cytokeratin 18, and connexin 26 could be differentiated from single Sertoli cells within tumor cell clusters by typical hCG but absence of vimentin immunoreactivity. In contrast to the current concept of CIS cells passing the tubular wall, these data provide evidence for an additional theory, i.e. that the switch from pre-invasive CIS to invasive tumour takes place in situ by tubular enlargement due to tumour cell proliferation followed by Sertoli cell degeneration and conversion of the tubular wall into connective tissue.

Distribution of type IV collagen subtypes in human testes and their association with spermatogenesis

OBJECTIVE

To evaluate the expression of type IV collagen [alpha1(IV) to alpha6(IV)] in testes and the association with spermatogenesis.

DESIGN

Retrospective immunohistochemical study.

SETTING

Division of Urology, Department of Organs Therapeutics, Faculty of Medicine, in a university hospital.

PATIENT(S)

Testicular biopsy specimens were obtained from 24 patients with varicocele, 5 with Sertoli cell-only syndrome (SCO), and 5 normal volunteers.

INTERVENTION(S)

Collection of testicular tissue and blood and semen sampling.

RESULT(S)

Expression of type IV collagen subtypes assessed by immunohistochemistry and clinical parameters such as seminogram and hormonal findings. In normal testes, the alpha1(IV) chain was seen in the basement membrane (BM) of seminiferous tubules as strongly stained irregular, wavy double lines, and the alpha2(IV) chain was slightly detected, whereas other testes showed little staining. In patients with varicocele and Sertoli cell-only syndrome, the BM was thicker and alpha1(IV) and alpha2(IV) chains were stained more intensely in the BM of seminiferous tubules than in normal testes. The expression of alpha1(IV) chain, not alpha2(IV), significantly correlated positively with the BM thickness, and negatively with sperm concentration, tubular diameter, and Johnsen score.

CONCLUSION(S)

Overabundance of the alpha1(IV) chain is associated with increased BM thickness and possibly related to spermatogenic dysfunction.

The role of expression of extracellular matrix proteins and epidermal growth factor receptor activity on fertilization capacity of testicular harvested spermatozoa

It has been suggested that multiple growth factors are crucial for spermatogenesis. We analyzed whether alterations on epidermal growth factor receptor activity and different expression pattern of extracellular matrix proteins had an impact on the fertilization capacity of spermatozoa and pregnancy rate after testicular sperm extraction and intracytoplasmic injection. Extracellular matrix proteins and epidermal growth factor receptor were immunohistochemically evaluated in testis of 88 patients with nonobstructive azoospermia. Testicular sperm extraction and intracytoplasmic injection procedure was also performed in 32 of the patients for whom mature sperm could be harvested from the testicular tissue. While collagen Type-IV and laminin activity percentages were 33.1% and 86.4% in motile sperm harvested testicular tissue, these activities were 23.3% and 89.3% in immotile sperm harvested testicular tissue, respectively. In addition, the mean epidermal growth factor receptor expression was higher in immotile than motile sperm obtained tissue (56.4% vs. 51.1%, P=0.4928). There was no statistically significant relationship between the extracellular matrix protein and epidermal growth factor receptor expression patterns and sperm motility, fertilization and pregnancy rates in testicular sperm extraction and intracytoplasmic injection. However, further studies are required to investigate the relationship between other growth factors and sperm fertilization capacity.

Morphological and histochemical characteristics of the lamina propria in scrotal and abdominal testes from postpubertal boars: correlation with the appearance of the seminiferous epithelium

This study was undertaken to investigate the morphological characteristics and lectin affinity of the testicular lamina propria in healthy boars and in unilateral and bilateral abdominal cryptorchid boars. The lamina propria of scrotal testes from healthy boars and unilateral cryptorchid boars was constituted by an innermost noncellular layer, the basal lamina, and by 2 layers of peritubular cells, each separated by a fibrous layer. The noncellular layers contained collagen fibres and glycoconjugates with abundant N-acetylgalactosamine, galactose, fucose, N-acetylglucosamine and neuraminic acid residues. The inner peritubular cell layer was composed of myoid cells, the outer layer of fibroblasts. In the abdominal testes of unilateral and bilateral cryptorchid boars, the lamina propria of nondegenerating and degenerating seminiferous tubules appeared thickened due to an increased content of collagen fibres and glycoconjugates. Glycoconjugates showed decreased amounts of fucose, neuraminic acid and galactose, and increased amounts of N-acetylglucosamine residues. The basal lamina formed infoldings toward the seminiferous epithelium and contained small cells. Both inner and outer peritubular cells were fibroblasts of immature appearance. In degenerated seminiferous tubules of bilateral cryptorchid boars, the lamina propria was composed of a thickened and collagenised basal lamina, without peritubular cells and with a low content of glycoconjugates. In scrotal testes, therefore, the lamina propria was implicated in tubular contractility and in mediating the communication and the substrate diffusion between seminiferous tubules and interstitial tissue. Cryptorchidism induced morphological and histochemical alterations in the lamina propria of abdominal testes, which may be linked to evidence from other studies of lack of tubular contractility and defective cell-cell communication and substrate diffusion. The severity of these anomalies correlated with the severity of Sertoli cell alterations.

Testicular biopsy. Contemporary interpretation

Biopsy of the testis is not universally accepted in contrast with biopsies of other organs. The pathologist studies and reports on the pathophysiology of the testicular biopsy specimen. Methodology requires the inclusion of qualitative and quantitative studies, the evaluation of the lesion's evolution (prognosis), and, often, therapeutic advice regarding treatment. Cooperation between pathologists and clinicians optimizes the utility of the biopsy for the patient.

Evidence that α5β1 integrins mediate Leydig cell binding to fibronectin and enhance Leydig cell proliferation stimulated by a Sertoli cell-secreted mitogenic factor in vitro

We reported previously that coculture of immature rat Sertoli cells with Leydig cells or the addition of a concentrate from Sertoli cell-conditioned medium (SCCM) stimulated Leydig cell [(3)H]-thymidine incorporation, increased cell number, and altered Leydig cell morphology (Wu and Murono, 1994). In the present studies, the effect of various extracellular matrix proteins on immature Leydig cell binding, proliferation and response to SCCM concentrate was investigated. Pretreatment of culture wells with 50 μg/mL collagen I or 10 μg/mL laminin inhibited Leydig cell binding to culture wells about 95 and 89%, respectively; however, 5 μg/mL fibronectin did not change the level of attachment. The binding of Leydig cells to fibronectin was reduced by antifibronectin or-β1 integrin antibodies (66 and 91%, respectively). Treatment of culture wells with five or 50 μg/mL fibronectin alone increased [(3)H]thymidine incorporation about twofold. When Leydig cells were cultured in wells precoated with increasing concentrations of fibronectin and then treated with SCCM concentrate for 2 d, [(3)H]-thymidine incorporation increased progressively with the concentration of fibronectin, beyond the levels observed with SCCM concentrate alone. This response was associated with increases in both Leydig cell number and labeling indices. When Leydig cells were cultured on fibronectin, their numbers increased by 3.7-and 5.1-fold following treatment with SCCM concentrates or coculture for 6 d, respectively; whereas, they increased 2.6- and 3.9-fold, respectively, when cultured on plastic. Labeling indices of Leydig cells cultured on plastic for 2 d and treated with SCCM or cocultured were 6.9 and 11.9%, respectively, while labeling indices of Leydig cells grown on fibronectin increased further to 17.6 and 26.3%, respectively. α5β1 integrin complexes and α5 integrin mRNA were expressed in Leydig cells, suggesting that binding to fibronectin may be mediated by α5β1 integrins, a fibronectin receptor. These results suggest that Leydig cell proliferation stimulated by a Sertoli cell-secreted mitogenic factor(s) is enhanced by Leydig cell binding fibronectin, and that this binding may be mediated by α5β1 integrins.

The origin of testicular microliths

The origin and development of eosinophilic bodies and microliths were studied histochemically and immunohistochemically in 29 human testes from prepubertal and adult males with different diseases. Non-calcified and partially calcified eosinophilic bodies were found mainly in infants and children. Most of the eosinophilic bodies were apparently located within the seminiferous tubules, where they were surrounded by a double Sertoli cell layer. Serial sections revealed that these tubules were configurated abnormally, either displaying a spiral course or forming a cap-like structure over the eosinophilic bodies that were actually extratubular. Completely calcified bodies (microliths) were found mainly in testes from adult men. The microliths were intratubular and appeared to be surrounded by a double layer of Sertoli cells. Eosinophilic bodies stained with eosin, periodic-acid-Schiff and silver methenamine like the tunica propria of seminiferous tubules. The peripheral band showed immunoreaction to both anti-laminin and anti-type IV collagen antibodies, similar to the basal lamina. Microliths were von Kossa-positive and immunostained similarly to the eosinophilic bodies. The present results suggest that a microlith is formed as a small eosinophilic body in the tunica propria. Afterwards, the body increases in size by deposit of new substances and compresses the seminiferous tubule which forms a ring or cap around it. Thereafter, the body undergoes calcification and becomes a microlith which compresses the seminiferous epithelium and enters the tubule.

Laminin and aminoterminal propeptide of type III procollagen in seminal plasma from fertile and vasectomized men

The components of the extracellular matrix, laminin and aminoterminal propeptide of type III procollagen (PIIINP) were determined in seminal plasma of 50 patients with vasectomy and of 50 age-matched fertile patients. The concentration of laminin was highly significantly (P < 0.001) elevated in the fertile group as compared to the vasectomy group, whereas the concentrations of PIIINP were not significantly different between these two groups. Only weak correlations were observed between the concentrations of laminin and PIIINP. It is suggested that part of the laminin found in seminal plasma is derived from the ductus deferens, while the source of PIIINP is probably located at an upper part of the urogenital tract.

Testosterone immunoexpression in human Leydig cells of the tunica albuginea testis and spermatic cord. A quantitative study in normal foetuses, young adults, elderly men and patients with cryptorchidism

A semi-quantitative study of the extra-parenchymal Leydig cells in the tunica albuginea testis and spermatic cord was performed on histological sections immunostained with anti-testosterone antibodies in the testes and spermatic cords obtained from human foetuses, adults and elderly men without testicular or related diseases (autopsy specimens), as well as from adult men with cryptorchidism (surgical specimens). The albugineal Leydig cells appeared in small groups in the vicinity of blood vessels. The Leydig cells of the spermatic cord usually appeared inside or around nerve trunks. The percentages of testes and spermatic cords with extra-parenchymal Leydig cells were higher in the cryptorchid testis group than in the normal male groups. The number of Leydig cells per mm2 in the tunica albuginea testis was higher in normal adult males than in foetuses. This number decreased in elderly men and increased markedly in cryptorchidism. The number of Leydig cells per mm2 in the spermatic cord was also higher in normal adults than in foetuses and it did not change with either advancing age or cryptorchidism. In foetuses, the percentage of cells intensely immunostained by anti-testosterone antibodies in the tunica albuginea and spermatic cord did not differ significantly from that found in the testicular parenchyma, whereas in the other three groups (adult, elderly, and cryptorchid men) the percentages of these cells in the tunica albuginea and spermatic cord were significantly lower than in the testicular parenchyma.

The peritubular myofibroblasts in the testes from normal men and men with Klinefelter's syndrome. A quantitative, ultrastructural, and immunohistochemical study

The ultrastructure and immunostaining with antibodies against actin, desmin, and vimentin were studied in the peritubular myofibroblasts of testes from normal men and men with Klinefelter' syndrome (KS). The seminiferous tubules were classified into five types (a-e), related to the progressive degree of sclerosis measured as thickening of the lamina propria. In control testes, only types a and b tubules were present, whereas the testes from men with KS showed types b, c, d, and e tubules. The ultrastructural study revealed abundant microfilament bundles with electron-dense bodies in the cell periphery of the myofibroblasts in a and b tubules. In c tubules, the microfilament bundles of the myofibroblasts were lacking in electron-dense bodies. Myofibroblasts in tubules d and e showed scanty microfilament bundles. Immunostaining of peritubular myofibroblasts with anti-actin antibodies was intense in tubule types a-c and scanty in types d and e. Immunostaining of myofibroblasts with anti-desmin antibodies was intense in tubule types a and b, and negative in types c-e. Immunostaining with anti-vimentin antibodies was weak in tubule types a-c and intense in types d and e. Quantitative study revealed that with the progression of sclerosis, the number and volume per cross-sectioned tubule of actin-containing cells and, mainly, desmin-containing cells decrease while the number and volume of vimentin-containing cells increase.

The concentration pattern of laminin, hyaluronan, and aminoterminal propeptide of type III procollagen in seminal fluid

The extracellular matrix components laminin, N-terminal propeptide of type III procollagen (PIIINP) and hyaluronan (HA) were determined in seminal fluids of 119 patients submitted for diagnosis of infertility. The concentrations of laminin and HA, but not those of PIIINP, were elevated in seminal fluid in comparison to their ranges of concentration in normal sera. Only weak correlations were observed between the concentrations of the three matrix components. The concentration of HA was negatively correlated with sperm count and ejaculate volume. Laminin was positively correlated with sperm count, the age of patients, and highly significantly with the concentrations of acrosin. A highly significant positive correlation was also found between PIIINP and fructose. By analysis of variance it could be shown that patients with azoospermia and oligozoospermia have significantly higher levels of HA than those with normospermia. Patients with terato- and asthenozoospermia showed no characteristic pattern of the matrix components.

Immunohistochemical and quantitative study of interstitial and intratubular Leydig cells in normal men, cryptorchidism, and Klinefelter's syndrome

Testicular specimens from normal men and men with cryptorchidism (CR) or Klinefelter's syndrome (KS) were taken, processed for light microscopy, and stained with the avidin-biotin peroxidase complex method for immunohistochemical detection of testosterone. The Leydig cells were classified by their morphology (normal, multivacuolated, and pleomorphic Leydig cells) and by their staining affinity for anti-testosterone antibodies (T-, T+, and T++ cells), and the average numbers of each cell type for each group of testes were calculated. Normal testes showed morphologically normal interstitial Leydig cells (96.0 +/- 10 per cent) and multivacuolated Leydig cells (4.0 +/- 1 per cent). Cryptorchid testes showed normal Leydig cells (85.8 +/- 11 per cent) and multivacuolated Leydig cells (14.2 +/- 2.3 per cent). Men with KS showed normal Leydig cells (78.9 +/- 9.1 per cent), multivacuolated Leydig cells (9.2 +/- 1.2 per cent), and pleomorphic Leydig cells (11.0 +/- 1.8 per cent). The percentage of T++ cells was higher in normal testes (29.4 +/- 2.1 per cent) than in CR (11.4 +/- 2.2 per cent) and KS testes (6.3 +/- 0.7 per cent). This suggests reduced functional Leydig cell activity in CR and KS. Multivacuolated Leydig cells showed weaker immunostaining than did normal Leydig cells in all the testicular groups. No immunostaining was shown by pleomorphic Leydig cells. Intratubular Leydig cells were only found in CR and KS. Immunostaining was weaker in intratubular Leydig cells than in interstitial Leydig cells. This suggests that intratubular location reduces functional activity of Leydig cells.