Identification of meiotic and postmeiotic gene expression in testicular tissue of patients histologically classified as Sertoli cell only

CREM variants rs4934540 and rs2295415 conferred susceptibility to nonobstructive azoospermia risk in the Chinese population

To evaluate the association of variants related to spermatogenesis with susceptibility to Chinese idiopathic nonobstructive azoospermia (NOA), seventeen tag single-nucleotide polymorphisms (SNPs) in CREM, ACT, KIF17b, and SPAG8 were analyzed in 361 NOA patients and 368 controls by Sequenom iplex technology. The results showed that two CREM SNPs, rs4934540 and rs22954152, were significantly associated with NOA and played protective roles against the disease (P value with Bonferroni correction = 0.00017, odds ratio [OR] = 0.624 and P = 0.012, OR = 0.686, respectively). Haplotype analysis of CREM gene variants suggested that haplotype CGTG of the SNPs, rs4934540, rs2295415, rs11592356, and rs1148247, exhibited significant protective effect against the occurrence of NOA (P = 0.001, OR = 0.659). The haplotype TATG conferred a significantly increased risk of NOA (P = 0.011, OR = 1.317). Furthermore, making use of quantitative RT-PCR, we demonstrated that relative mRNA expression of CREM in NOA patients with maturation arrest was only one-third of that in the controls with normal spermatogenesis (P < 0.0001). Our findings indicated that the polymorphisms of CREM gene were associated with NOA in the Chinese population and low CREM expression might be involved in the pathogenesis of spermatogenesis maturation arrest.

Long-term spermatogonial survival in cryopreserved and xenografted immature human testicular tissue

BACKGROUND

Preservation of the male germ line in prepubertal boys undergoing gonadotoxic treatment is a crucial consideration in terms of their future quality of life. As these patients do not yet produce spermatozoa for freezing, only immature tissue is available for storage. We studied the survival, proliferation and differentiation capacity of spermatogonia after cryopreservation and long-term transplantation of immature testicular tissue pieces.

METHODS

Single pieces of testicular tissue (2-8 mm(3)) from prepubertal boys (7-14 years) were cryopreserved, thawed and transplanted into the scrotum of mice for 6 months. Upon removal, histological, immunohistochemical and ultrastructural analyses and testicular sperm extraction (TESE) were used to evaluate the tissue.

RESULTS

Histology showed 55 +/- 42% of tubules to be intact. MAGE-A4 immunostaining showed mean spermatogonial recovery to be 3.7 +/- 5.5%, with 35% of these cells expressing Ki67, evidencing proliferation in tissue from boys <14 years of age. No apoptosis was found, as demonstrated by the absence of active caspase-3 and TUNEL staining. Numerous premeiotic spermatocytes, a few spermatocytes at the pachytene stage and spermatid-like cells were observed. No immunostaining was observed for lactate dehydrogenase-C, ACE or proacrosin, indicating that the spermatid-like structures observed by histology did not express the meiotic and post-meiotic markers characteristic of normal spermatids. No ultrastructural alterations of the tissue were encountered.

CONCLUSIONS

The present study demonstrates that spermatogonia are able to survive and proliferate after cryopreservation and long-term transplantation. Complete regeneration of normal spermatogenesis was not observed since, beyond the pachytene stage, no adequate characterization of germ cells was obtained. Further studies are thus required to investigate the differentiation potential of cryopreserved germ cells.

Testicular histopathological diagnosis as a predictive factor for retrieving spermatozoa for ICSI in non-obstructive azoospermic patients

OBJECTIVE

Histological testicular pattern has a predictive role in the possibility of finding spermatozoa for ICSI in cases of non-obstructive azoospermia because some individuals could show residual spermatogenic sites in the testis. The aim of this study was to evaluate the sperm retrieval rate in each of the histopathological groups (hypospermatogenesis--Hypo, spermatogenic maturation arrest--MA, Sertoli cell only--SCO and testicular hyalinization) in patients assisted in our clinic.

MATERIALS AND METHODS

Retrospective study from March 1997 to October 2002. We analyzed 14 patients with mean age of 34.3 +/- 0.7, with non-obstructive azoospermia. All patients were submitted to previous diagnostic biopsy (Bx) elsewhere and came to our institution for treatment. After an average of 12 months (8-20), they were submitted to a new Bx procedure to retrieve sperm.

RESULTS

Previous diagnostic Bx showed the following histopathological results: 5 patients with MA, 4 with Hypo and 5 SCO. In the following Bx (for sperm retrieval) spermatozoa was found in 33% of the procedures in patients with MA, 50% in patients with Hypo and 40% of the procedures in patients with SCO.

CONCLUSION

Previous diagnostic Bx can help in patient counseling concerning the result of sperm retrieval.

Novel testis-expressed profilin IV associated with acrosome biogenesis and spermatid elongation

A novel profilin, named profilin IV, was cloned and characterized as a testicular isoform, distinct from the previously described testis-specific profilin III. Profilin IV showed only 30% amino acid identity with the other mammalian profilins; nevertheless, database searches produced significant alignments with the conserved profilin domain. Northern blot analysis and in situ transcript hybridization suggested that profilin IV, like profilin III, is transcribed in the germ cells. However, the timing of their expression during post-natal development of rat testis and in the rat spermatogenetic cycle was distinct. In the human testis, profilin IV mRNA expression correlates with the presence of germ cells suggesting that it may be a suitable molecular diagnostic parameter to supplement conventional histopathological diagnostics in the assessment of testicular biopsies. The predicted profilin IV protein was verified employing an anti-oligopeptide antibody. Western blot analysis detected an immunorelated testicular protein of approximately 14 kDa. Immunohistochemistry revealed an intracellular protein of the rat, the mouse and the human testis accumulating asymmetrically in the cytoplasm of round and elongating spermatids with its perinuclear location coinciding with the position of the developing acrosome-acroplaxome and the manchette. Profilin IV thus may regulate testicular actin cytoskeleton dynamics and play a role in acrosome generation and spermatid nuclear shaping.

[Usefulness and necessity of the andrologist in assisted reproductions units]

In this issue we make a review of our experience in the management of the sterile men: protocols used for the study of men's sterility, causes and specific treatments, surgical recovery of spermatozoa and screening before IVF or IVF-ICSI. We concluded that with an adequate protocol, it's possible to establish the aetiology of men's infertility in a 78.8% of the cases and it's also possible to initiate a specific treatment in almost a 47.8% of men. Results of specific treatment, with a previous selection of patients, could be better than those of assisted reproduction techniques. Best results are obtained in cases of vaso-vasostomy (vasectomy reversal) and obstruction of ejaculatory duct. It's also needed a study of genetics causes and bad prognostic circumstances in those men whose partner is going on with an IVF or IVF-ICSI cycle.

Possible predictive factors for ICSI? Molecular biology techniques in combination with therapeutic testicular biopsies

Applying intracytoplasmic sperm injection (ICSI), the selection of an unsuccessful spermatozoon results in great emotional consequences for the couple. Therefore, there is a need for a prognostic parameter to estimate their chances for successful fertility treatment. This review summarizes both the main reasons for spermatogenic impairment, and possible predictive factors for successful sperm retrieval applying testicular sperm extraction and outcome of ICSI. While basic sperm parameters, aetiology and type of spermatozoa, and serum follicle-stimulating hormone and inhibin levels have been shown to be unrelated to the outcome of ICSI, Y-chromosome microdeletions are known to have a negative influence on the fertilizing capacity of spermatozoa. Recently, a significant correlation has been reported between the protamine-1 to protamine-2 mRNA ratio in haploid spermatids of testicular biopsies and the ability of spermatozoa for successful fertilization of an oocyte. In future, both the outstanding role of the haploid spermatids and the involvement of molecular biological techniques will improve the role of therapeutic testicular biopsies.

Correlation between fluorescence in situ hybridization and testicular biopsy for the prediction of spermatogenesis in 37 patients with nonobstructive azoospermia

OBJECTIVES

We applied interphase fluorescence in situ hybridization (FISH) to testis sections to examine the evidence of spermatogenesis in patients with nonobstructive azoospermia. This technique was evaluated and compared with conventional testicular histopathologic findings for the possibility of additional clinical applications.

METHODS

Thirty-seven consecutive patients with nonobstructive azoospermia were carefully evaluated clinically. Testes were biopsied for both sperm extraction and histopathologic examination. FISH staining was performed with a CEP 18 SpectrumAqua/CEP X SpectrumGreen/CEP Y SpectrumOrange probe.

RESULTS

Eight of 11 cases (sensitivity 73%) that were found to have spermatids on the histopathologic slides also were proven to produce haploid cells by FISH staining. On the other hand, 21 of the 26 cases (specificity 81%) for which no spermatids could be found on the histopathologic slides also had only diploid cells by FISH staining. On the basis of the good correlation between the FISH staining and conventional histopathologic findings, we could confirm the diagnosis of spermatogenesis using both methods.

CONCLUSIONS

FISH staining of testicular sections allows more reliable prediction of spermatogenesis and provides benefits for a patient's decision regarding fertility counseling.