PERK/IRE1α通路介导的肾细胞凋亡：GRP78/CHOP在狼疮性肾炎中的诊断价值

doi:10.12122/j.issn.1673-4254.2025.10.01

摘要/Abstract

摘要：

目的明确狼疮性肾炎（LN）患者血清中内质网应激（ERS）蛋白GRP78/CHOP含量变化，分析其诊断价值及蛋白表达改变对应的肾脏病理特征。方法基于系统性红斑狼疮（SLE）多中心队列研究建立样本库，随机抽取LN患者60例和无肾脏受累的SLE患者35例，ELISA法检测GRP78和CHOP在患者血清中的含量，分析其与临床特征的相关性以及对LN和LN活动期的诊断能力。以MRL/lpr小鼠为LN动物模型，检测小鼠血清GRP78和CHOP表达及肾脏中内质网凋亡相关指标。结果 LN患者血清GRP78和CHOP高于无肾脏受累的SLE患者（P<0.05）；GRP78和CHOP在LN活动期患者中也高于稳定期患者（P<0.05）；关联分析提示血清GRP78和CHOP水平与SLEDAI评分、24 h尿蛋白正相关；ROC结果显示CHOP对LN（AUC=0.762）和LN活动（AUC=0.933）具有较高的诊断能力。与临床结果类似，LN小鼠GRP78和CHOP升高（P<0.05），而与该指标相关的PERK和IRE1α通路蛋白在肾脏中表达也升高（P<0.05），TUNEL染色显示LN小鼠肾脏细胞凋亡增加，凋亡相关蛋白表达升高（P<0.05）。结论 GRP78/CHOP在狼疮性肾炎中的表达升高，可能与PERK/IRE1α双通路介导的ERS凋亡相关。

关键词: 狼疮性肾炎, 内质网应激通路, 凋亡, GRP78, CHOP, PERK/IRE1α

Abstract:

Objective To examine the changes in serum levels of endoplasmic reticulum stress (ERS) proteins GRP78/CHOP in patients with lupus nephritis (LN) and analyze their diagnostic value and association with renal pathological features. Methods From a sample bank established based on a multicenter cohort study of systemic lupus erythematosus (SLE), 60 LN patients and 35 SLE patients without renal involvement were randomly selected. ELISA was used to detect serum levels of GRP78 and CHOP in the patients to analyze their correlation with clinical features and their diagnostic ability for LN and active LN. MRL/lpr mice were used as an animal model of LN to examine their serum levels of GRP78 and CHOP expression and renal expressions of endoplasmic reticulum apoptosis-related proteins. Results Serum GRP78 and CHOP levels were significantly higher in LN patients than in SLE patients without renal involvement (P<0.05), and were also higher in active LN patients than in patients in the stable phase (P<0.05). Correlation analysis indicated that serum GRP78 and CHOP levels were positively correlated with SLEDAI scores and 24-h urinary protein. ROC analysis showed that CHOP had a high diagnostic ability for LN (AUC=0.762) and active LN (AUC=0.933). Consistent with the clinical findings, serum GRP78 and CHOP levels were elevated in LN mice, and the expressions of PERK and IRE1α pathway proteins were also increased in the kidneys of the mice. TUNEL staining showed increased renal cell apoptosis and elevated renal expressions of apoptosis-related proteins in LN mice. Conclusion Serum levels of GRP78/CHOP are increased in LN patients possibly in association with ERS-induced apoptosis mediated by the PERK/IRE1α dual pathway.

Key words: lupus nephritis, endoplasmic reticulum stress pathway, apoptosis, GRP78, CHOP, PERK/IRE1α

汪一晗, 张维庆, 方婷, 谢志敏, 范永升, 王新昌. PERK/IRE1α通路介导的肾细胞凋亡：GRP78/CHOP在狼疮性肾炎中的诊断价值[J]. 南方医科大学学报, 2025, 45(10): 2055-2061.

Yihan WANG, Weiqing ZHANG, Ting FANG, Zhimin XIE, Yongsheng FAN, Xinchang WANG. Elevated expressions of GRP78/CHOP in lupus nephritis: their diagnostic value and association with PERK/IRE1α pathway-mediated renal cell apoptosis[J]. Journal of Southern Medical University, 2025, 45(10): 2055-2061.

图/表 8

表1 LN组和SLE组间一般资料比较

Tab.1 Comparison of general clinical data between the patients in LN group and SLE group

Item	LN (n=60)	SLE (n=35)	P
Age (year, Mean±SD)	41.31±2.08	38.24±2.73	0.28
Female [n (%)]	56 (93.33%)	33 (94.29%)	0.85
BMI (kg/m²)	21.84±0.60	22.99±0.98	0.35
SLEDAI	8.14±0.74	5.25±0.58	0.05
Illness duration (year)	8.18±1.33	8.90±1.90	0.57
24 h UTP (g/d)	1192.82±243.66	119.17±24.58	0.00
Anti-dsDNA[+(%)]	24 (40%)	11 (31.43%)	0.40
Anti-Sm[+(%)]	13 (21.67%)	8 (22.86%)	0.89
Hb (g/L)	115.25±3.04	123.04±5.66	0.10
PLT (10⁹/L)	188.19±10.36	213.90±13.08	0.31
WBC (10¹²/L)	5.81±0.50	5.68±0.49	0.63
C3 (g/L)	0.70±0.04	0.74±0.04	0.80
C4 (g/L)	0.14±0.02	0.12±0.02	0.20

图1 LN和SLE患者血清中GRP78和CHOP水平

Fig.1 Level of serum GRP78 and CHOP in LN and SLE patients. A: Serum level of GRP78 in LN and SLE patients. B: Serum level of CHOP in LN and SLE patients. C: Serum level of GRP78 in LN patients in active and remission phase. D: Serum level of CHOP in LN patients in active and remission phase. **P<0.01, ***P<0.001.

图2 GRP78和CHOP与临床指标相关性

Fig.2 Correlation of GRP78 and CHOP with clinical parameters in LN patients. *P<0.05, **P<0.01.

图3 GRP78和CHOP对LN的诊断能力

Fig.3 Diagnostic capabilities of GRP78 and CHOP for LN. A: ROC curves of peripheral blood GRP78 and CHOP for diagnosing LN. B: ROC curves of GRP78 and CHOP for diagnosis of LN in the active phase.

图4 LN小鼠疾病特征性表现

Fig.4 Disease characteristics in the mouse models of LN. A: Serum level of IL-6 in LN and control groups. B: Serum level of TNF-α in LN and control groups. C: Serum level of anti-dsDNA in LN and control groups. D: Renal HE staining, PAS staining and IgG staining showing mesangial cell proliferation (blue arrow), lymphocytes infiltration (green arrow), and basement membrane thickening (red arrow) (scale bar=50 μm). **P<0.01, ***P<0.001.

图5 LN小鼠血清GRP78和CHOP水平

Fig.5 Serum levels of GRP78 and CHOP in mouse models of LN. A: Serum levels of GRP78 in LN and control groups. B: Serum levels of CHOP in LN and control groups. **P<0.01.

图6 LN小鼠肾脏凋亡增加

Fig.6 Renal apoptosis is increased in mouse models of LN. A: Kidney TUNEL staining in LN and control groups (scale bar=50 μm). B: Expression of apoptosis-related proteins in LN and control groups. C: Relative expression levels of apoptosis-related proteins in the two groups. *P<0.05, **P<0.01.

图7 LN小鼠肾脏ERS凋亡相关蛋白表达

Fig.7 Expressions of proteins related to endoplasmic reticulum stress apoptosis in the kidney of LN mice. A: Protein bands in Western blotting of endoplasmic reticulum stress-related proteins. B-I: Relative PERK phosphorylation level and relative expression levels of PERK, ATF4, CHOP, IREα, IREα, phosphorylated JNK, and JNK, respectively. *P<0.05, **P<0.01, ***P<0.001.

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