OBJECTIVE To characterize the tubular environment in testicular biopsy tissues from patients with Klinefelter syndrome (KS). DESIGN Observational immunohistochemical study. SETTING Academic research unit. PATIENT(S) Males with KS and controls at different developmental time points: fetal, prepubertal, peripubertal, and adult. INTERVENTION(S) Immunohistochemical analysis of testicular biopsies samples to characterize maturation of Sertoli cells and tubular wall components-peritubular myoid cells (PTMC) and extracellular matrix (ECM) proteins. MAIN OUTCOME MEASURE(S) Intensity of antimüllerian hormone staining; proportion of Sertoli cells expressing androgen receptor (AR); and expression of tubular wall markers as characterized by identifying abnormal staining patterns. RESULT(S) Decreased expression for alpha smooth muscle actin 2 (ACTA2) was observed in peripubertal and adult KS as well as in Sertoli cell only (SCO) patients. Altered expression patterns for all ECM proteins were observed in SCO and KS biopsy tissues compared with controls. Only for collagen I and IV were altered expression patterns observed between KS and SCO patients. In peripubertal samples, no statistically significant differences were observed in the maturation markers, but altered ECM patterns were already present in some samples. CONCLUSION(S) The role of loss of ACTA2 expression in PTMC in the disintegration of tubules in KS patients should be further investigated. Future research is necessary to identify the causes of testicular fibrosis in KS patients. If the mechanism behind this fibrotic process could be identified, this process might be altered toward increasing the chances of fertility in KS patients.

中文翻译：

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Klinefelter 患者睾丸活检中生精小管内干细胞生态位成分的表征

目的 表征 Klinefelter 综合征 (KS) 患者睾丸活检组织中的管状环境。设计 观察性免疫组织化学研究。设置学术研究单位。患者在不同发育时间点患有 KS 和对照的男性：胎儿、青春期前、青春期周围和成人。INTERVENTION(S) 睾丸活检样本的免疫组织化学分析，以表征支持细胞和管壁成分 - 管周肌样细胞 (PTMC) 和细胞外基质 (ECM) 蛋白的成熟。主要结果测量(S) 抗苗勒管激素染色强度；表达雄激素受体（AR）的支持细胞的比例；和通过识别异常染色模式表征的管壁标记物的表达。结果 在青春期和成人 KS 以及仅支持细胞 (SCO) 患者中观察到 α 平滑肌肌动蛋白 2 (ACTA2) 表达降低。与对照相比，在 SCO 和 KS 活检组织中观察到所有 ECM 蛋白的表达模式改变。KS 和 SCO 患者之间仅观察到胶原蛋白 I 和 IV 的表达模式改变。在青春期样本中，未观察到成熟标志物的统计学显着差异，但某些样本中已经存在改变的 ECM 模式。结论（S） PTMC 中 ACTA2 表达缺失在 KS 患者肾小管崩解中的作用应进一步研究。未来的研究对于确定 KS 患者睾丸纤维化的原因是必要的。如果可以确定这种纤维化过程背后的机制，