The Study Of Expression Of TNF-α MRNA And TNF-R₂ In Human Spermatozoa

Objective: In recent years, cytokines and their effects on the reproductive ability have intrigued field widely. Cytokines are immunoactive peptides, they are the important factors in local regulation and signal transduction between different cells of the testis. Under physiological situation, immune cells, leydig cell and spermatogonia secrete tumor nerosis factor-alpha (TNF-alpha) which can regulate the proliferation and differentiation of the germinal cells. They play an important role in the neuro-endocrine modulation, testicular function and spcrmatogenesis in male reproductive system. The expression of tumor nerosis factor-alpha in human spermatozoa have not been reported yet. The paper aimed to indentify the expression of TNF-alpha mRNA in the spermatozoa of fertile men and its variation of TNF-alpha mRNA in the spermatozoa of infertile men and to confirm the presence of tumor necrosis factor receptor (TNF-R2) in spermatozoa of fertile men, and provide experimental evidence for the direct action of tumor necrosis factor onthe spermatozoa.Methods: using Reverse Transcription Polymerase Chain Reaction (RT-PCR) and sequence analysis to identify the expression of TNF-alpha mRNA in the spermatozoa of 13 fertile and 30 infertiles men . Using Western blotting to identify the expression of tumor necrosis factor receptor (TNF-R2) in the spermatozoa of 15 fertile men.Results: TNF-alpha mRNA was expressed in human spermatozoa and its cDNA sequence was identical to that of other cell's in human being, the density of spermatozoa, percentage of active spermatozoa, percentage of normal form of spermatozoa and the expression of TNF-alpha mRNA in infertile men was significantly lower than it in fertile men. Tumor necrosis factor receptor (TNF-R2) was expressed in spermatozoa of all the 15 fertile men.Conclusion: we concluded that human spermatozoa might synthesizes TNF-alpha and which may modulate the spermatozoa functions by autocrine pattern. Some unknown factors impaired the productions of TNF-alpha in infertile spermatozoa, and which may be responsible for the poor quality of semen and infertile status in these patients. In addition, the spermatozoa of fertile men have tumornecrosis factor receptor (TNF-R2),which may transmit the cytokines signal into cytoplasm and modulate the spermatozoa function.