| [Objective] Fluorosis is one of the endemic diseases spread in the world.A large number of studies have proved that fluoride can damage the male reproductive system in both human and animals.However,the mechanism is not clear.Spermatic flagellum is a mature sperm motility organ with unique microtubules and highly conserved during evolution,which plays an important role in the maintenance of sperm motility.The study aims to investigate whether fluoride affects sperm quality and fertilization function by affecting mouse testicular sperm flagellar structure and related gene expression,and provides a theoretical basis for studying the mechanism and prevention and treatment of fluorine affecting male reproductive system.[Method] 40 ICR male mice were randomly divided into 4 experimental groups according to their body weight,with 10 mice in each group,including: 0,25,50 and 100 mg/L Na F in deionized water.After8 weeks treatment,the testes and epididymides were taken out for future study.The testes and epididymides were detected by tissue sections and HE staining,and the ultrastructure of transverse section of sperm tail structure was observed by transmission electron microscope(TEM).In addition,the expressions of genes and proteins related to flagellum structure were detected by Real time PCR,Western Blotting and Immunofluorescence techniques.[Results] 1.After 8 weeks,disordered arrangement of spermatogenic cells,reduced number of elongated sperms in the lumen,incomplete wall of the seminiferous tubules and thinner thickness of the lumen were observed by HE stainning in all the treated groups compared with the control group.Moreover,in the 50 and 100 mg/L Na F groups,part of the cells was detached in the lumen.And disordered germ cells,widened interstitial and the vacuolar-like pathological phenomenon were detected in 100 mg/L Na F group.2.Compared with the control group,the sperm flagellum was damaged in different degrees.For example,the fiber sheath was broken and the structure of “9+2” was also damaged.3.Compared with the control group,fluoride reduced the m RNA expression levels of Akap3 and Akap4 genes related to fiber sheath assembly in the flagellum structure of male mice testicular sperm.The m RNA expression levels of Akap3 and Akap4 in the 100mg/L Na F treatment group were significantly lower than those in the control group(p < 0.01;p < 0.05).Meanwhile,fluoride reduced the protein expression levels of AKAP3 and AKAP4 in 100 mg/L Na F treatment group(p < 0.01).4.In comparison with the control group,the m RNA expression of Cfap44 was significantly decreasedin 100 mg/L Na F treatment group(p<0.05);Meanwhile,fluoride decreased the protein expression of CFAP44 in all treated groups,especially in 100 mg/L Na F treatment group,the protein expression of CFAP44 was significantly decreased(p<0.05).Besides,the m RNA expression of Cfap43 was significantly decreased in 50 and 100 mg/L Na F groups(p<0.05)..5.After 8 weeks,the m RNA expression of Ccdc40,a key gene attached to the dynamin arm of the testicular flagellum in male mice was measured.Compared with the control group,the m RNA level of Ccdc40 was significantly lower in the 100mg/L Na F treatment group(p < 0.05).6.Hydin is a central pair(CP)gene in sperm flagellum structure.Compared with the control group,the m RNA expression level of Hydin was significantly lower in the 100 mg/L Na F groups(p < 0.001).Meanwhile,The protein expression levels of HYDIN in 50 and 100mg/L Na F treatment group were significantly lower than that in the control group(p < 0.05;p < 0.001)[Conclusion] Fluoride can alter the morphology and structure of the testicular tissue and sperm flagella and cause and sperm abnormalities.Fluoride decreases the m RNA expression levels of Cfap43、Akap3、Akap4、Ccdc40、Hydin、Cfap44 and protein expression levels of AKAP3、AKAP4、CFAP44、HYDIN,which may be one of the reasons that fluoride interferes with the structure of sperm flagellum and sperm motility. |
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