Rai Richa, Chauhan Sudhir Kumar, Singh Vikas Vikram, Rai Madhukar, Rai Geeta
Department of Molecular and Human Genetics, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India.
Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India.
Immunol Lett. 2015 Mar;164(1):25-32. doi: 10.1016/j.imlet.2015.01.007. Epub 2015 Feb 2.
Generation of autoantigens of nuclear origin, like dsDNA and extractable nuclear antigens (ENA) have largely been associated with dysregulated apoptosis and defective clearance of apoptotic debris in SLE. Heat shock protein (HSP) 27 has been reported to have anti-apoptotic properties hence it was of interest to study the expression of HSP27 and its regulatory molecule Brn3a and hsa-miR-939 in SLE patients with distinct autoantibodies specificities. SLE patients were categorized into three subsets based on their distinct sero-positivity for either anti-dsDNA antibody alone (anti-dsDNA(+) group) or anti-ENA antibody alone (anti-ENA(+) group) or both (anti-dsDNA(+) ENA(+) group). We investigated the mRNA and protein expression of HSP27 and Brn3a in peripheral blood leukocytes (PBLs) by real-time reverse transcriptase PCR and Western blotting. Expression of apoptosis markers caspase 3 and poly (ADP-ribose) polymerase (PARP) was determined by Western blotting. Hsa-miR-939 expression was determined using TaqMan(®) miRNA assay. In this study, we report significant downregulation of HSP27 in anti-ENA(+) patients and increased expression of caspase 3 and PARP in both anti-ENA(+) and anti-dsDNA(+) SLE subsets. A negative correlation was observed between the expression of HSP27 and apoptosis markers caspase 3 and PARP. Decreased Brn3a expression was observed in anti-ENA(+) SLE patients, which correlated positively with HSP27 expression. Expression of hsa-miR-939, which has a potential target site for Brn3a 3' UTR, was also elevated specifically in anti-ENA(+) patients. The decreased expressions of HSP27, Brn3a along with elevated levels of hsa-miR-939 are selectively associated with anti-ENA(+) patients and HSP27 was observed to be inversely associated with apoptosis. These findings are suggestive of distinct regulatory processes operative in SLE patient subsets with different autoantibody specificities.
核源性自身抗原的产生，如双链DNA和可提取核抗原（ENA），在很大程度上与系统性红斑狼疮（SLE）中凋亡失调和凋亡碎片清除缺陷有关。据报道，热休克蛋白（HSP）27具有抗凋亡特性，因此研究HSP27及其调节分子Brn3a和hsa-miR-939在具有不同自身抗体特异性的SLE患者中的表达具有重要意义。根据SLE患者单独抗双链DNA抗体呈血清阳性（抗双链DNA（+）组）、单独抗ENA抗体呈血清阳性（抗ENA（+）组）或两者均呈血清阳性（抗双链DNA（+）ENA（+）组），将SLE患者分为三个亚组。我们通过实时逆转录聚合酶链反应和蛋白质印迹法研究外周血白细胞（PBLs）中HSP27和Brn3a的mRNA和蛋白表达。通过蛋白质印迹法测定凋亡标志物半胱天冬酶3和聚（ADP-核糖）聚合酶（PARP）的表达。使用TaqMan® miRNA检测法测定hsa-miR-939的表达。在本研究中，我们报告抗ENA（+）患者中HSP27显著下调，抗ENA（+）和抗双链DNA（+）SLE亚组中半胱天冬酶3和PARP表达增加。观察到HSP27表达与凋亡标志物半胱天冬酶3和PARP之间呈负相关。在抗ENA（+）SLE患者中观察到Brn3a表达降低，其与HSP27表达呈正相关。在抗ENA（+）患者中，具有Brn3a 3'非翻译区潜在靶位点的hsa-miR-939表达也特异性升高。HSP27、Brn3a表达降低以及hsa-miR-939水平升高与抗ENA（+）患者选择性相关，并且观察到HSP27与凋亡呈负相关。这些发现提示在具有不同自身抗体特异性的SLE患者亚组中存在不同的调节过程。
