Transaldolase And Testosterone Synthesis In Puberty Mice Leydig Cells

Transaldolase is the key enzyme of the nonoxidative phase of Pentose Phosphate Pathway, which regulates the ultimate output of Pentose Phosphate Pathway, namely, riboseS- phosphate and NADPH. Ribose 5-phosphate participate the synthesis of nucleotide acid, CoA and NAD+, while NADPH is most important reductive equilibrium required by all biometabolic reactions and can maintain glutathione at a reduced state. Recent studies have proved that Transaldolase plays a vital role in HIV-induced apoptosis, Multiple Sclerosis, tumor, Liver Cirrhosis, organ development and embryogenesis. The expression and enzymatic activity of Transaldolase vary in tissue-specific, developmental-stage-relevant and Physiology-Pathology-different manners.Previous research of Lachaise had demonstrated that in crab steroidogenic organ, ecdysterone synthesis was positively related to expression and enzymatic activity of Transaldolase. Transaldolase was partly phosphorylated by cGMP-induced kinase during steroidogenesis. The down regulating factor of ecdysteronesis-Molt Inhibiting Hormone also inhibits the expression and activity of Transaldolase.Due to the high conservation of Transaldolase gene and the homology of Transaldolase protein structure in different creatures. We set out to study on the potential role of Transaldolase on steroidogenesis in mammals.The study was divided into two parts: the first part was to probe whether Transaldolase was expressed in mice testes and whether it has any isoforms. The second part was to set up the technology of isolation and primary culture of Leydig cells, and research on the relationship between Transaldolase and testosterone synthesis in puberty mice Leydig cells including three aspects concerning mRNA level, protein level andenzymatic activity.1 The expression research of Transaldolase in mice testesUsing SDS-PAGE and Western blotting methods, Transaldolase expression level in 7-day-old and 40-day-old mice testes were determined. Transaldolase expression in testes of 7-day-old mice were 47.8% higher that in 40-day-old mice. And with Two-dimensional gel electrophoresis Western blotting we separated more than 10 isoforms of Transaldolase. The A8 isoform was hardly expressed in testes of 7-day-old mice, while in 40-day-old mice it was highly expressed. The rapid growth of 7-days-old mice accompanies high frequency of cell metabolism, which may cause the over expression of Transaldolase gene. The A8 isoform was highly expressed in adult mice testes, so it may be related to spermatogenesis and testosterone synthesis.2 Studies on the relationship between Transaldolase and testosterone synthesis in puberty mouse Leydig cells.Leydig cells from 30-days-old mice testes were isolated and cultured. All Leydig cells were divided into two groups, experimental groups incubated with HCG and control groups. Testosterone concentration of Leydig cells cultured 2 and 8 hours were measured by Enzyme-linked immunoabsordent assay. By RT-PCR and Western blotting Transaldolase expression in mRNA level and protein level were determined. Meanwhile Transaldolase enzymatic activity was measured by the method describedby Lachaise. Results showed when HCG stimulated the synthesis of testosterone in mice Leydig cells, Transaldolase activity increased simultaneous. While Transaldolase expression in mRNA and protein levels did not show differences in experimental and control groups. Results demonstrated that Transaldolase activity was closely correlated with testosterone synthesis in mice Leydig cells. Alternation ofTransaldolase activity may be related to posttranslational modifications but not to the elevation of Transaldolase gene expression.