人类趋化素样因子超家族2在精索静脉曲张大鼠模型中的表达

目的：通过建立精索静脉曲张大鼠模型，探讨人类趋化素样因子超家族2（chemokine like factor-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link transmembrane domain-containing protein 2, CMTM2）对精索静脉曲张大鼠生精过程的影响。方法：选取雄性SD大鼠40只（体重220~330 g，6~7周龄），将大鼠随机分为精索静脉曲张持续4、12周后处死取样组，和相应的接受假手术处理的对照组，每组均为10只大鼠。通过手术进行左肾静脉缩窄建立左侧精索静脉曲张的大鼠模型。将实验组和对照组大鼠于4周或12周后处死，取出左侧睾丸，游离附睾中精子，观察并计算精子密度与活力，测量生精小管外径、内径及上皮直径改变，并进行免疫组织化学分析以判断CMTM2蛋白的表达状况。结果：与对照组相比，精索静脉曲张4周组中大鼠的精子密度［（63.9±7.1）×106/mL vs.（74.3±5.0）×106/mL］和活力［（58.7%±7.9%） vs. （66.1%±4.3%）］ 轻度下降（t=1.432, 1.563; P=0.076, 0.059），精索静脉曲张12周组中大鼠的精子密度［（40.5±7.2）×106/mL vs.（71.1±4.5）×106/mL］和活力［（35.2%±8.5%） vs. (63.4%±4.1%)］显著下降（t=3.754, 3.933; P=0.004, 0.002）。此外，CMTM2蛋白的表达水平在精索静脉曲张组也出现明显下降，对照组CMTM2水平为精索静脉曲张12周组的（2.3±0.4）倍（t=1.978; P=0.039）。4周时，精索静脉曲张组生精小管外径出现轻度降低［（271.1±8.4）μm vs. （280.0±8.1）μm，t=1.361， P =0.132］，而12周组则出现明显降低［（198.2±10.2） μm vs. （255.8±12.7）μm，t=2.125， P=0.003］，此外，精索静脉曲张12周组的生精小管上皮直径出现明显下降［（54.1±1.5）μm vs.（75.5±4.1）μm，t=2.246，P=0.021］。结论：在精索静脉曲张大鼠模型中，精索静脉曲张与CMTM2蛋白水平降低相关，同时可导致睾丸生精小管直径变小及精子密度与质量受损。

Expression of chemokine like factor-like myelin and lymphocyte and related proteins for vesicle trafficking and membrane link transmembrane domain-containing protein 2 in rats with varicocele

Objective:To investigate whether chemokine like factor (CKLF)-like myelin and lympho-cyte and related proteins for vesicle trafficking and membrane link (MARVEL)transmembrane domain-containing protein 2 (CMTM2)is involved in spermatogenesis in varicocele induced sub-fertility rats and to discuss the possible mechanisms.Methods:Forty male SD rats (body weight:220 -330 g,age:6 -7 weeks)were randomly divided into 4 groups:varicocele for 4 weeks,varicocele for 12 weeks,sham operation for 4 weeks and sham operation for 12 weeks,with 10 rats in each group.These rats were intro-duced by partially ligating left kidney veins for the experimental groups,and the sham surgery groups as controls were executed with exactly the same surgery as in the experimental groups except for the ligation. The rats in control and experimental groups for 4 and 12 weeks were killed after laparotomy at the end of 4 and 12 weeks,respectively,the left testes and epididymis were taken out for counting the sperm,ob-serving the seminiferous tubule change and immunochemistry for CMTM2.The changes included sperm density and motility,the outer diameter and inner diameter change and the changes of epithelium and the CMTM2 expression in immunochemistry.Results:Compared with the control groups,the sperm density [(63.9 ±7.1)×106 /mL vs.(74.3 ±5.0)×106 /mL]and motility[(58.7% ±7.9%)vs.(66.1% ± 4.3%)]were reduced slightly in group of varicoele for 4 weeks,respectively (t =1.432,1.563;P =0.076,0.059,respectively ).Varicocele significantly caused a decrease in sperm concentration [(40.5 ±7.2)×106 /mL vs.(71.1 ±4.5)×106 /mL]and motility [(35.2% ±8.5%)vs.(63.4% ± 4.1%)]at 12 weeks,compared with the related sham groups (t =3.754,3.933;P =0.004,0.002, respectively).Additionally,testis CMTM2 exhibited the same disparity,that is,the CMTM2 protein ex-pression in varicocele group was significantly reduced,with the ratio of sham group to varicocele group at the end of 12 weeks 2.3 ±0.4 (t =1.978;P =0.039).In the evaluation of seminiferous tubules diame-ter,the external [(198.2 ±10.2)μm vs.(255.8 ±12.7)μm,t =2.125,P =0.003]and epithelium diameter [(54.1 ±1.5)μm vs.(75.5 ±4.1)μm,t =2.246,P =0.021]were decreased compared with the sham-related groups and previous varicocele groups.In all the varicocele groups,all types of sperm motility decreased compared with the related sham-operated group (P <0.05).Conclusion:This study suggests varicocele has a detrimental effect on CMTM2 levels and decreases spermatogonia cell number,seminiferous tubules diameter,and sperm indices.CMTM2 is associated with sperm changes in rats with varicocele,and further studies are needed to study the mechanism.