Kaga Hajime, Matsumura Hirotoshi, Suzuki Takehiro, Dohmae Naoshi, Odaka Masafumi, Komatsuda Atsushi, Takahashi Naoto, Wakui Hideki
Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
Department of Life Science, Graduate School of Engineering Science, Akita University, 1-1 Tegatagakuen-machi, Akita City, Akita, 010-8502, Japan.
Clin Proteomics. 2022 Jul 14;19(1):26. doi: 10.1186/s12014-022-09365-x.
Anti-phospholipase A2 receptor autoantibody (PLA2R Ab)-associated membranous nephropathy (MN) is the most common form of primary MN (pMN). On the other hand, bucillamine (BCL), an antirheumatic drug developed in Japan, was reported to cause a rare form of secondary MN (sMN). Between these MN forms, comparative proteomic analysis of glomerular proteins has not been performed.
We used renal biopsy specimens from 6 patients with PLA2R Ab (+) pMN, 6 patients with PLA2R Ab (‒) pMN, 6 patients with BCL-induced sMN, and 5 control cases (time 0 transplant biopsies). Proteins were extracted from laser-microdissected glomeruli and analyzed using mass spectrometry. The quantification values of protein abundance in each MN group were compared with those in the control group.
More than 800 proteins with high confidence were identified. Principal component analysis revealed a different distribution between the pMN and sMN groups. For further analysis, 441 proteins matched with ≥ 3 peptides were selected. Among the pMN and sMN groups, we compared the profiles of several protein groups based on the structural and functional characteristics, such as immunoglobulins, complements, complement-regulating proteins, podocyte-associated proteins, glomerular basement membrane proteins, and several proteins that are known to be associated with kidney diseases, including MN. In all MN groups, increased levels of immunoglobulins (IgG, IgA, and IgM), complements (C3, C4, and C9), complement factor H-related protein 5, type XVIII collagen, calmodulin, polyubiquitin, and ubiquitin ligase were observed. For some proteins, such as type VII collagen and nestin, the fold-change values were significantly different between the pMN and sMN groups.
Between the pMN and BCL-induced sMN groups, we observed common and different alterations in protein levels such as known disease-associated proteins and potential disease marker proteins.
抗磷脂酶A2受体自身抗体（PLA2R Ab）相关的膜性肾病（MN）是原发性MN（pMN）最常见的形式。另一方面，布西拉明（BCL）是一种在日本研发的抗风湿药物，据报道可导致一种罕见的继发性MN（sMN）形式。在这些MN形式之间，尚未对肾小球蛋白进行比较蛋白质组学分析。
我们使用了6例PLA2R Ab（+）pMN患者、6例PLA2R Ab（-）pMN患者、6例BCL诱导的sMN患者的肾活检标本以及5例对照病例（移植时0期活检）。从激光显微切割的肾小球中提取蛋白质，并使用质谱进行分析。将每个MN组中蛋白质丰度的定量值与对照组进行比较。
鉴定出800多种可信度高的蛋白质。主成分分析显示pMN组和sMN组之间存在不同的分布。为了进一步分析，选择了441种与≥3个肽段匹配的蛋白质。在pMN组和sMN组中，我们根据结构和功能特征比较了几个蛋白质组的谱，如免疫球蛋白、补体、补体调节蛋白、足细胞相关蛋白、肾小球基底膜蛋白以及几种已知与肾脏疾病（包括MN）相关的蛋白质。在所有MN组中，均观察到免疫球蛋白（IgG、IgA和IgM）、补体（C3、C4和C9）、补体因子H相关蛋白5、 XVIII型胶原、钙调蛋白、多聚泛素和泛素连接酶水平升高。对于某些蛋白质，如VII型胶原和巢蛋白，pMN组和sMN组之间的倍数变化值存在显著差异。
在pMN组和BCL诱导的sMN组之间，我们观察到蛋白质水平存在共同和不同的变化，如已知的疾病相关蛋白和潜在的疾病标志物蛋白。
