Stage-specific localization of transforming growth factor β1 and β3 and their receptors during spermatogenesis in men

Aim: To investigate the stage-specific localization of transforming growth factor (TGF) β1 and β3 during spermatogenesis in adult human testis. Methods: The localization of TGFβ1 and β3 was investigated by immunohis tochemical staining method employing specific polyclonal antibodies. Results: Both TGFβ1 and β3 and their recep tors were preponderant in the Leydig celis. TGFβ1 could not be detected in the seminiferous tubules. TGFβ3 and TGFβ-Receptor (R) I were mainly seen in the elongated spermatids, while TGFβ-RⅡ in the pachytene spermatocytes and weak in the spermatogonia, spermatids and Sertoli celis. Only TGFβ-RⅡ was detected in the Sertoli celis. TGFβ3, TGFβ-RⅠ and TGFβ-RⅡ showed a staining pattern dependent upon the stages of the seminiferous epithelium cycle. Conclusion: TGFβ isoforms and their receptors are present in the somatic and germ celis of the adult human testis, suggesting their involvement in the regulation of spermatogenesis.

Expression and localization of Smadl, Smad2 and Smad4 proteins in rat testis during postnatal development

<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive irnmunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smadl, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. Conclusion: The present data provide direct evidences for the molecular mechanism of TGF-βaction in rat testes during postnatal development and spermatogenesis.

Expression and significance of Rap1A in testes ofazoospermic subjects

Aim: To evaluate the Rap1A mRNA expression and its significance in the testes of normal and azoospermic subjects. Methods: A cDNA microarray that contained Rap1A and some other genes such as RBM, EIF1 AY was used to identify the differential gene expression profiles between the normal and azoospermic testes. cDNA probes were prepared by labeling mRNA from azoospermic and normal testicular tissues through reverse transcription with Cy5-dUTP and Cy3-dUTP, respectively. The mixed cDNA probes were then hybridized with cDNA microarray (each containing 4096 unique human cDNA sequences). The fluorescent signals were scanned and the values of Cy5-dUTP and Cy3-dUTP on each spot were analyzed and calculated. In situ hybridization was employed to detect the expression of RaplA in the testes of 10 fertile and 39 azoospermic subjects. Results: One hundred and twenty-eight differentially expressed genes were found to be possibly related to azoospermia, of which 56 were up-regulated and 72, down-regulated genes. The mRNA expression of RaplA in the spermatogenic cells of azoospermic was stronger than that in those of the fertile testes. Conclusion: Rap1A may play certain roles in the development of azoospermia.

Protective effect of rhIL-1β on pancreatic islets of alloxan-induced diabetic rats

AIM: To observe the protective effect of rhIL-1β on pancreatic islets of alloxan-induced diabetic rats. METHODS: Protection of rhIL-1β on pancreatic islets of alloxan-induced diabetic rats (n=5) was demonstrated with methods of immunohistochemistry and stereology. The concentration of serum glucose was measured by GOD method and that of serum insulin by RIA. RESULTS: The concentration of serum glucose increased but that of insulin decreased after administration of alloxan (150mg/kg), and the volume density and numerical density of the islets were zero. In rhIL-1β pretreated rats, although the concentration of serum insulin decreased (from 11.9±3.0mIU/L to 6.1±1.6mIU/L,P<0.05), that of glucose was at normal level compared with the control group. As compared with alloxan group, the concentration of serum glucose in rhIL-1β pretreated rats decreased (from 19.4±8.9mmol/L to 12.0±4.0mmol/L, P<0.05) and the volume density increased(0/L to. 1/L, P<0.05). CONCLUSION: rhIL-1β pretreatment may have protective effect on the islets of alloxan-induced diabetic rats.

REGULAR EXPRESSION OF DISCOIDIN DOMAIN RECEPTOR 2 IN THE IMPROVED ADJUVANT-INDUCED ANIMAL MODEL FOR RHEUMATOID ARTHRITIS

Objective To investigate the expression of discoidin domain receptor 2 (DDR2) of fibroblast-like synovial cells in im- proved adjuvant-induced animal (AIA) model for rheumatoid arthritis (RA) and to provide evidence for DDR2’s antagonist use clinically. Methods AIA was modified by administrating 0.1 mL of complete Freund’s adjuvant (CFA, mixed with 5 mg Bacillus Calmette-Guerin vaccine/mL) into rats’ right hind paws and 0.125 mL tumor necrosis factor-α (2 U/mL) into right ankles and subpatellar fatty tissue. The expression of DDR2 in fibroblast-like synovial cells was assessed using immunohistochemistry, immunofluorescence histochemistry, and in situ hybridization methods. Levels of anti-collagen II antibody were measured using enzyme-linked immunosorbent assay. Results Given the terms mentioned above, we found a more practical rat model, apparently decreasing immunization time (average 3-5 days). DDR2 can be detected upon the 15th day of immunization; expression gradually increased with time going on, and reaching a peak 35 days after immunization before gradually decreasing. Serum anti-collagen II antibody showed similar expression patterns as DDR2, but reached peak later than DDR2, about 40 days after immunization. Conclusion Regular expression of DDR2 in animal models infers its important role in the pathological process of RA.

Transforming growth factor β receptor Ⅱ expression inexperimental cryptorchidism and apoptosisin spermatogenic cells in rats

Objective: To study the transforming growth factor β receptor Ⅱ (TGFβ-R Ⅱ) expression in experimental cryptorchidism and apoptosis in spermatogenic cells in rats. Methods: The apoptosis of spermatogenic cells was detected by means of the terminal deoxynucleotldyl transferase mediated dUTP nick end lableling method (TUNEL) and the TGFβ-R Ⅱ expression was observed with the immunohistochemistry SABC methods. Results: There was a significant increase in the TGFβ-R Ⅱ expression in unilateral undescended testes (UUTs) compared with that in contralateral descended testes (CDTs, P<0.01). However, there was a significant and time-dependent increase in the mean apoptotic index in UUTs than in CDTs. Conclusion: TGFβ-R Ⅱ may play an important role in spermatogenic cell apoptosis.