Associations between m-type phospholipase A2 receptor,human leukocyte antigen gene polymorphisms and idiopathic membranous nephropathy

A review of progress on complement and primary membranous nephropathy

Primary membranous nephropathy (PMN) is a predominant cause of adult nephrotic syndrome, with its incidence witnessing a progressive surge over time. Approximately 35% to 47% of patients progress to renal failure within 10 years, causing a huge social burden. Within China, the proportion of PMN in primary glomerular disease exhibits a gradual ascension. Recent studies have shown that the 3 activation pathways of complement: the classical pathway, mannose-binding lectin pathway, and alternative pathway, are all involved in the pathogenesis of PMN. Despite historical limitations in detecting C1q deposits on the glomeruli of PMN in the past, recent studies have confirmed the classical pathway is implicated in patients with PMN. Considering the dysregulation of the complement system has been observed in PMN, complement inhibitors become increasingly promising. Several clinical trials are presently underway to evaluate the efficacy of complement inhibitors, such as MASP2 antagonists (OMS721), C3 and C3b antagonists (APL2), FD inhibitors (BCX9930), C3aR antagonists (SB290157 and JR14a), FB inhibitors (LNP023). This article reviews the recent research progress on the role of the complement pathway in the pathogenesis of PMN, and underscores the importance of continued research into the complement pathway and its inhibitors, which may pave the way for groundbreaking advancements in the management of PMN.

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

Association of 10 Polymorphisms in PLA2R1 and HLA DQA1 Genes with Primary Membranous Nephropathy Risk: A Meta-Analysis and a Meta-Regression

Background

Although, several studies have assessed the association of the phospholipase A2 receptor (PLA2R) and HLA-DQA1 SNPs with primary membranous nephropathy (PMN), results were inconsistent and between-studies heterogeneity needs to be investigated.

Objectives

The aim of this review was to summarize existing data on the contribution of 10 SNPs in the PLA2R and HLA-DQA1 genes to PMN susceptibility and to investigate the between-studies heterogeneity by subgroup analyses and meta-regressions.

Design

This study was performed according to the PRISMA guidelines for systematic reviews and meta-analyses.

Data sources and methods

An electronic literature search for eligible studies among all papers published prior to January 10, 2024, was conducted through PubMed, EMBASE, Web of science and Scopus databases. Meta-analyses together with subgroup analyses and meta-regressions were performed for the 10 following SNPs: rs4664308, rs3749117, rs3749119, rs35771982, rs3828323, rs16844715, rs1511223, rs6757188, rs2715918, and rs2187668.

Results

Combined analyses revealed a significant increase in PMN risk conferred by the following alleles: rs4664308*A, rs3749117*T, rs3749119*C, rs35771982*G, rs3828323*C, rs16844715*C, rs1511223*A, rs2715918*A, and rs2187668*A, all P-values < .001. Moreover, the PLA2R-rs4664308/HLA-DQA1-rs2187668 interaction was significantly associated with an increased PMN risk, P < .001. However, there was a substantial between-studies heterogeneity for some SNPs. Subgroup analyses by ethnicity for the 9 PLA2R SNPs did not show any cross-ethnic disparity. Inversely, the risk conferred by the HLA-DQA1 rs2187668*A allele was significantly higher in Caucasians (OR [95% CI] = 3.929 [3.251-4.748]) than in Asians (OR [95% CI] = 2.537 [1.94-3.318], P = .007. Besides, meta-regressions revealed for the majority of investigated SNPs significant correlations of the effect size with albumin, 24-hours proteinuria, serum creatinine, and eGFR levels. Hence, the influence on PMN risk conferred by the PLA2R and HLA-DQA1 SNPs was rather noted in patients with a severe disease.

Conclusion

This meta-analysis showed that 9 out of the 10 investigated SNPs in PLA2R and HLA-DQA1 genes were associated with increased PMN risk. Heterogeneity could be due to disparate patient groups in terms of disease presentation for almost all SNPs, and ethnicity for the HLA-DQA1 rs2187668 SNP.

Registration

This review has been registered on PROSPERO: CRD42024506729. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024506729.

Phospholipid metabolism-related genotypes of PLA2R1 and CERS4 contribute to nonobese MASLD

BACKGROUND

Abnormal phospholipid metabolism is linked to metabolic dysfunction-associated steatotic liver disease (MASLD) development and progression. We aimed to clarify whether genetic variants of phospholipid metabolism modify these relationships.

METHODS

This case-control study consecutively recruited 600 patients who underwent MRI-based proton density fat fraction examination (240 participants with serum metabonomics analysis, 128 biopsy-proven cases) as 3 groups: healthy control, nonobese MASLD, and obese MASLD, (n = 200 cases each). Ten variants of phospholipid metabolism-related genes [phospholipase A2 Group VII rs1805018, rs76863441, rs1421378, and rs1051931; phospholipase A2 receptor 1 (PLA2R1) rs35771982, rs3828323, and rs3749117; paraoxonase-1 rs662 and rs854560; and ceramide synthase 4 (CERS4) rs17160348)] were genotyped using SNaPshot.

RESULTS

The T-allele of CERS4 rs17160348 was associated with a higher risk of both obese and nonobese MASLD (OR: 1.95, 95% CI: 1.20-3.15; OR: 1.76, 95% CI: 1.08-2.86, respectively). PLA2R1 rs35771982-allele is a risk factor for nonobese MASLD (OR: 1.66, 95% CI: 1.11-1.24), moderate-to-severe steatosis (OR: 3.24, 95% CI: 1.96-6.22), and steatohepatitis (OR: 2.61, 95% CI: 1.15-3.87), while the paraoxonase-1 rs854560 T-allele (OR: 0.50, 95% CI: 0.26-0.97) and PLA2R1 rs3749117 C-allele (OR: 1.70, 95% CI: 1.14-2.52) are closely related to obese MASLD. After adjusting for sphingomyelin level, the effect of the PLA2R1 rs35771982CC allele on MASLD was attenuated. Furthermore, similar effects on the association between the CERS4 rs17160348 C allele and MASLD were observed for phosphatidylcholine, phosphatidic acid, sphingomyelin, and phosphatidylinositol.

CONCLUSIONS

The mutations in PLA2R1 rs35771982 and CERS4 rs17160348 presented detrimental impact on the risk of occurrence and disease severity in nonobese MASLD through altered phospholipid metabolism.

Association between PLA2R gene polymorphism and idiopathic membranous nephropathy in Heilongjiang Chinese

Background

The aim of this study was to investigate the correlation between the phospholipase A2 receptor (PLA2R) gene polymorphism and idiopathic membranous nephropathy (IMN) in Heilongjiang Chinese.

Methods

Thirty-five patients with IMN confirmed by renal biopsy attending the Heilongjiang Hospital of Traditional Chinese Medicine between June 2021 and December of 2021 were selected as the IMN group, and a group of 25 healthy participants from the Physical Examination Center of Heilongjiang Hospital of Traditional Chinese Medicine were enrolled as healthy controls. Polymerase chain reaction (PCR) was used to identify and genotype 8 single-nucleotide polymorphism (SNP) loci (rs16844715, rs2715918, rs2715928, rs35771982, rs3749119, rs3828323, rs4665143, and rs6757188) of PLA2R and to analyze the PLA2R gene polymorphisms that correlated with IMN. SPSS 26.0 statistical software was used for data analysis, and the chi-squared (χ²) goodness-of-fit test was used to determine whether each SNP genotype and allele in the PLA2R gene complied with the Hardy-Weinberg equilibrium. The qualitative data were analyzed via χ² or Fisher exact probability method. Logistic regression was used to analyze risk factors, and the odds ratios (ORs) values and 95% confidence intervals (CIs) were calculated. α=0.05 was taken as the test level, and P<0.05 was considered statistically significant.

Results

Statistically significant differences were found in the genotype and allele frequencies of rs35771982 and rs3749119 between the IMN and control groups (P<0.05). Logistic regression analysis showed that the genotypes rs35771982 GG and rs3749119 CC were associated with IMN susceptibility. Statistically significant differences in uric acid level were found between the rs35771982 GG and CG + CC genotypes (P<0.05), while statistically significant differences in serum albumin were detected between rs3749119 CC and the CT + TT genotypes (P<0.05). Multivariate logistic regression analysis showed that gender, age, and triglyceride levels affected the occurrence of IMN (P<0.05).

Conclusions

The PLA2R gene polymorphisms rs35771982 and rs3749119 in Heilongjiang Chinese may be related to IMN susceptibility and correlated with clinical indicators of IMN. Gender, age, and triglyceride levels may influence the occurrence of IMN.

Salvianolic acid B attenuates membranous nephropathy by activating renal autophagy via microRNA-145-5p/phosphatidylinositol 3-kinase/AKT pathway

The abnormal proliferation and inflammatory response of the mesangial cells play a crucial role in the progression of membranous nephropathy (MN). Herein, this study aimed to investigate the therapeutic effect of Salvianolic acid B (SalB) on MN-induced mesangial abnormalities and its underlying mechanisms. MN models were established in cationic bovine serum albumin-induced Sprague-Dawley rats and lipopolysaccharide-induced human mesangial cells (HMCs). Following SalB and microRNA-145-5p antagomir treatment, kidney function was investigated by 24-hours urine protein, serum creatinine, and blood urea nitrogen. Pathological changes of kidney were investigated by Periodic acid Schiff staining. CD68 and IgG were detected by immunofluorescence in glomerulus. Mesangial autophagosomes were observed by transmission electron microscope. MicroRNA-145-5p inhibitor, mimic, LY294002, and SalB were used to treat with HMCs. In kidney and HMCs, IL-1 β, IL-2, IL-6, TNF-α and microRNA-145-5p was detected by quantitative real-time PCR. Phosphatidylinositol 3-kinase (PI3K), phosphorylated AKT, AKT, beclin1, and microtubule-associated protein light chain 3 (LC3) levels were detected by Western blot. HMCs proliferation and cycle were detected by Cell Counting Kit-8 and flow cytometry. LC3 were detected by LC3-dual-fluorescent adenovirus in HMCs. Our results showed that SalB significantly ameliorated kidney function and pathological changes. Furthermore, it significantly alleviated proliferation, inflammation and activated autophagy in mesangial cells. Moreover, microRNA-145-5p antagomir accentuated MN while microRNA-145-5p inhibitor and LY294002 encouraged proliferation and inflammation through PI3K/AKT pathway in HMCs. Collectively, our study demonstrated that SalB activated renal autophagy to reduce cell proliferation and inflammation of MN, which was mediated by microRNA-145-5p to inhibit PI3K/AKT pathway, and ultimately attenuated MN.