难治性突发性聋患者外周血单个核细胞内HDAC2表达与其预后的相关性分析

摘要

Objective To evaluate expression of HDAC2 in peripheral blood mononuclear cells(PBMCs)from glucocorticoid-resistant versus glucocorticoid-sensitive patients with sudden sensorineural hearing loss and identi-ty the relationship between the level of HDAC2 and glucocorticoid insensitivity.Methods PBMCs were collected from10 patients with deviation of nasal septum (control group)and 20 sudden sensorineural hearing loss patients be-fore and after intratympanic methylprednisolone for 10 days.We divided the SSNHL patients into 2 groups (GC sensitive group and GC insensitive group)according to their hearing recovery.Real time PCR and HDAC2 Assay Kit were used to detect the expression level of HDAC2 mRNA and HDAC2 activity in PBMCs.The data were analyzed with SPSS 17.0 software.ResuIts Before intratympanic methylprednisolone,the level of HDAC2 activity were sig-nificantly depressed in SSNHL patients,while the HDAC2 mRNA expressing much higher than the control group. The expression level of HDAC2 mRNA increased significantly after intratympanic methylprednisolone.The HDAC2 activity in GC sensitive group increased significantly.ConcIusion Knockdown of HDAC2 expression induces corti-costeroid in-sensitivity.Glucocorticoids can increase the expression of HDAC2 mRNA.HDAC2 activity can be down-regulated by post-translational modifications.%目的：探讨组蛋白去乙酰化酶2（histone deacetylase 2，HDAC2）水平与突发性聋（sudden sensorineu-ral hearing loss，SSNHL）患者糖皮质激素（glucocorticoid，GC）抵抗的关系。方法选择难治性 SSNHL 患者20例，所有患耳鼓室内灌注甲强龙20 mg/d，连续10天，同时辅以全身静脉滴注营养神经及改善微循环药物。对照组为10例正常听力志愿者。分离所有研究对象的外周血单个核细胞（peripheral blood mononuclear cell，PBMC），提取细胞核蛋白以及总 RNA，分别用 HDAC2活性检测试剂盒以及 real time PCR 的方法，检测受试者 PBMC 中HDAC2的蛋白活性以及 HDAC2 mRNA 的表达情况，并随访 SSNHL 患者听力，根据听力恢复情况将 SSNHL 患者分为 GC 有效组和 GC 无效组，探讨 HDAC2水平与 GC 抵抗的关系。结果20例 SSNHL 患者中，GC 有效8例，GC 无效12例，治疗前 GC 有效组及无效组患耳 PTA 分别为75．21±9．44和80．98±12．73 dB HL，治疗后分别为40．83±14．37和77．92±12．25 dB HL；治疗前突聋患者 HDAC2蛋白活性 OD 值（GC 有效组0．664±0．022， GC 无效组0．659±0．043）显著低于对照组（0．726±0．024），而 HDAC2 mRNA 表达量（GC 有效组0．079±0．023， GC 无效组0．083±0．047）显著高于对照组（0．035±0．022），治疗后，两组患者 HDAC2 mRNA 表达量（GC 有效组0．132±0．041，GC 无效组0．132±0．048）较治疗前升高，GC 有效组患者 HDAC2蛋白活性（0．730±0．033）上升并接近正常水平，而 GC 无效组患者 HDAC2蛋白活性（0．647±0．013）无明显变化。结论难治性 SSNHL 患者对GC 不敏感可能与 HDAC2蛋白活性降低有关，GC 可以促使 HDAC2 mRNA 的表达上调，GC 治疗无效的患者体内可能存在某种机制，对 HDAC2进行翻译后修饰，使 HDAC2蛋白活性降低，从而抑制组蛋白去乙酰化，导致其对激素治疗不敏感。