Calcyclin is differentially expressed in rat testicular cells

Alterations in proteoglycan synthesis selectively impair FSH-induced particulate cAMP-phosphodiesterase 4 (PDE4) activation in immature rat Sertoli cells

FSH-induced upregulation of cAMP-PDE4 activities was decreased in cultured Sertoli cells when alteration of cell proteoglycans (PGs) metabolism was simultaneously induced either by para-nitrophenyl beta-d-xyloside (PNPX) or by sodium chlorate. This effect was restricted to the particulate PDE4 activities and its timing was consistent with the half-life of Sertoli cell PGs. It did not result from alterations in Pde4d variants expression, the major FSH-regulated PDE4 in Sertoli cells. Moreover, lack of changes in the particulate levels of major immunoreactive 75 kDa and 90 kDa PDE4D proteins, corresponding likely to short PDE4D1 and long PDE4D3/D8/D9 isoforms respectively, suggested that the decrease in FSH-stimulated of PDE4 activities in chlorate- and PNPX-treated cells at the end of the 24-h incubation period resulted from the increased reversal of the activated particulate PDE4(D) activities back to unstimulated levels. By controlling FSH-stimulated particulate PDE4 inactivation through a still unknown mechanism (sustained activation of PKA or reduction of phosphoprotein phosphatase activities), cell PGs could be involved in the alteration of cAMP response to FSH accompanying the transition of Sertoli cells from proliferative to non-proliferative differentiated state.

The murine testicular transcriptome: characterizing gene expression in the testis during the progression of spermatogenesis

One of the most promising applications of microarrays is the study of changes in gene expression associated with the growth and development of mammalian tissues. The testis provides an excellent model to determine the ability of microarrays to effectively characterize the changes in gene expression as an organ develops from birth to adulthood. To this end, a developmental testis gene expression time course profiling the expression patterns of approximately 36 000 transcripts on the Affymetrix MGU74v2 GeneChip platform at 11 distinct time points was created to gain a greater understanding of the molecular changes necessary for and elicited by the development of the testis. Additionally, gene expression profiles of isolated testicular cell types were created that can aid in the further characterization of the specific functional actions of each cell type in the testis. Statistical analysis of the data revealed 11 252 transcripts (9846 unique) expressed differentially in a significant manner. Subsequent cluster analysis produced five distinct expressional patterns within the time course. These patterns of expression are present at distinct chronological periods during testis development and often share similarities with cell-specific expression profiles. Analysis of cell-specific expression patterns produced unique and characteristic groups of transcripts that provide greater insight into the activities, biological and chronological, of testicular cell types during the progression of spermatogenesis. Further analysis of this time course can provide a distinct and more definitive view into the genes implicated, known and unknown, in the maturation, maintenance, and function of the testis and the integrated process of spermatogenesis.

Construction of cDNA representational difference analysis based on two cDNA libraries and identification of garlic inducible expression genes in human gastric cancer cells

AIM: To elucidate molecular mechanism of chemopreventive efficacies of garlic against human gastric cancer (HGC).

METHODS: HGC cell line BGC823 was treated with Allitridi (a kind of garlic extract) and Allitridi-treated and parental BGC823 cDNA libraries were constructed respectively by using λZAP II vector. cDNA Representational Difference Analysis (cDNA RDA) was performed using BamH I cutting-site and abundant cDNA messages provided by the libraries. Northern blot analysis was applied to identify the obtained difference products.

RESULTS: Two specific cDNA fragments were obtained and characterized to be derived from homo sapiens folate receptorα (FRα) gene and calcyclin gene respectively. Northern blot results showed a 4-fold increase in FRα gene expression level and 9-fold increase in calcyclin mRNA level in BGC823 cells after Allitridi treatment for 72 h.

CONCLUSION: The method of cDNA RDA based on cDNA libraries combines the high specificity of cDNA RDA with abundant cDNA messages in cDNA library; this expands the application of cDNA library and increases the specificity of cDNA RDA. Up-regulation of FRα gene and calcyclin gene expressions induced by Allitridi provide valuable molecular evidence for the efficacy garlic in treating HGC as well as other diseases.