Research Centre for Medical Genetics, Moscow, Russia.
N. A. Alexeev Clinical Psychiatric Hospital №1, Moscow Healthcare Department, Moscow, Russia.
PLoS One. 2022 Jun 13;17(6):e0269130. doi: 10.1371/journal.pone.0269130. eCollection 2022.
Increased systemic oxidative stress is common in schizophrenia (SZ) patients. NADPH-oxidase 4 (NOX4) is the cell oxidoreductase, catalyzing the hydrogen peroxide formation. Presumably, NOX4 is the main oxidative stress factor in a number of diseases such as cardiovascular diseases and cancer. We hypothesized that NOX4 may be involved in the oxidative stress development caused by the disease in the schizophrenic patients' peripheral blood lymphocytes (PBL).
The SZ group included 100 patients (68 men and 32 women aged 28 ± 11 years). The control group included 60 volunteers (35 men and 25 women aged 25 ± 12 years). Flow cytometry analysis (FCA) was used for DNA damage markers (8-oxodG, ɣH2AX), pro- and antiapoptotic proteins (BAX1 and BCL2) and the master-regulator of anti-oxidant response NRF2 detection in the lymphocytes of the untreated SZ patients (N = 100) and the healthy control (HC, N = 60). FCA and RT-qPCR were used for NOX4 and RNANOX4 detection in the lymphocytes. RT-qPCR was used for mtDNA quantitation in peripheral blood mononuclear cells. Cell-free DNA concentration was determined in blood plasma fluorimetrically.
8-oxodG, NOX4, and BCL2 levels in the PBL in the SZ group were higher than those in the HC group (p < 0.001). ɣH2AX protein level was increased in the subgroup with high 8-oxodG (p<0.02) levels and decreased in the subgroup with low 8-oxodG (p <0.0001) levels. A positive correlation was found between 8-oxodG, ɣH2AX and BAX1 levels in the SZ group (p <10-6). NOX4 level in lymphocytes did not depend on the DNA damage markers values and BAX1 and BCL2 proteins levels. In 15% of PBL of the HC group a small cellular subfraction was found (5-12% of the total lymphocyte pool) with high DNA damage level and elevated BAX1 protein level. The number of such cells was maximal in PBL samples with low NOX4 protein levels.
Significant NOX4 gene expression was found a in SZ patients' lymphocytes, but the corresponding protein is probably not a cause of the DNA damage.
精神分裂症（SZ）患者的系统性氧化应激增加较为常见。NADPH 氧化酶 4（NOX4）是细胞氧化还原酶，催化过氧化氢的形成。据推测，NOX4 可能是心血管疾病和癌症等多种疾病中氧化应激发展的主要因素。我们假设 NOX4 可能参与了 SZ 患者外周血淋巴细胞（PBL）中由疾病引起的氧化应激发展。
SZ 组包括 100 名患者（68 名男性和 32 名女性，年龄 28 ± 11 岁）。对照组包括 60 名志愿者（35 名男性和 25 名女性，年龄 25 ± 12 岁）。使用流式细胞术分析（FCA）检测未经治疗的 SZ 患者（N = 100）和健康对照者（HC，N = 60）的淋巴细胞中 DNA 损伤标志物（8-oxodG、ɣH2AX）、促凋亡和抗凋亡蛋白（BAX1 和 BCL2）和抗氧化反应主调控因子 NRF2 的表达。使用 FCA 和 RT-qPCR 检测淋巴细胞中的 NOX4 和 RNA-NOX4。使用 RT-qPCR 检测外周血单个核细胞中的 mtDNA 定量。通过荧光法测定血浆中的细胞游离 DNA 浓度。
SZ 组 PBL 中的 8-oxodG、NOX4 和 BCL2 水平高于 HC 组（p < 0.001）。高 8-oxodG 水平亚组中的ɣH2AX 蛋白水平升高（p <0.02），而低 8-oxodG 水平亚组中的ɣH2AX 蛋白水平降低（p <0.0001）。SZ 组中 8-oxodG、ɣH2AX 和 BAX1 水平之间存在正相关关系（p <10-6）。淋巴细胞中的 NOX4 水平与 DNA 损伤标志物值以及 BAX1 和 BCL2 蛋白水平无关。在 HC 组的 15%的 PBL 中发现了一个小的细胞亚群（总淋巴细胞池的 5-12%），具有高水平的 DNA 损伤和升高的 BAX1 蛋白水平。在 PBL 样本中，NOX4 蛋白水平较低时，此类细胞数量最多。
在 SZ 患者的淋巴细胞中发现了显著的 NOX4 基因表达，但相应的蛋白可能不是 DNA 损伤的原因。
