Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, Institute of Nephrology, The Second Xiangya Hospital at Central South University, Changsha, China.
Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
Front Immunol. 2022 Mar 2;13:831253. doi: 10.3389/fimmu.2022.831253. eCollection 2022.
We previously showed that the rupture of Bowman's capsule (BC) promotes the progression of crescentic glomerulonephritis by enhancing the entry of CD8 T cells into the glomeruli. In the present study, we utilized digital spatial profiling to simultaneously profile the altered abundances of the messenger RNA (mRNA) transcripts and proteins in the glomerular and periglomerular areas of four biopsy samples of anti-neutrophil cytoplasmic autoantibody-associated glomerulonephritis (ANCA-GN) and two biopsy specimens of minimal change disease (MCD) controls. The paraffin-embedded biopsy samples were stained with collagen IV, CD45, and SYTO 13 to distinguish the glomeruli with periglomerular infiltration but intact BC, with focal BC rupture, and with extensive rupture of BC and glomeruli without crescent formation and leukocytic infiltration in ANCA-GN. By assessing multiple discrete glomerular areas, we found that the transcript expression levels of the secreted phosphoprotein-1 and its receptor CD44 were upregulated significantly in the glomeruli with more severe ruptures of BC, and their expression levels correlated positively with the fibrotic markers. We also found that both alternative and classic complement pathways were activated in the glomeruli from patients with ANCA-GN. Furthermore, M1 macrophages were involved mostly in the early stage of BC rupture, while M2 macrophages were involved in the late stage and may contribute to the fibrosis process of the crescents. Finally, loss of glomerular cells in ANCA-GN was likely mediated by apoptosis. Our results show that digital spatial profiling allows the comparative analysis of the mRNA and protein profiles in individual glomeruli affected differently by the disease process and the identification of potential novel mechanisms in ANCA-GN.
我们之前的研究表明，鲍曼氏囊（BC）的破裂通过增强 CD8 T 细胞进入肾小球，促进新月体性肾小球肾炎的进展。在本研究中，我们利用数字空间分析技术，同时对四例抗中性粒细胞胞质抗体相关性肾小球肾炎（ANCA-GN）活检样本和两例微小病变性肾病（MCD）对照活检样本的肾小球和肾小球旁区的信使 RNA（mRNA）转录本和蛋白质的改变丰度进行了分析。对石蜡包埋的活检样本进行了 IV 型胶原、CD45 和 SYTO13 染色，以区分具有肾小球旁浸润但 BC 完整、局灶性 BC 破裂、BC 广泛破裂且新月体形成和白细胞浸润的肾小球。通过评估多个离散的肾小球区域，我们发现，在 BC 破裂更严重的肾小球中，分泌型磷酸蛋白-1 及其受体 CD44 的转录表达水平显著上调，其表达水平与纤维化标志物呈正相关。我们还发现，替代和经典补体途径均在 ANCA-GN 患者的肾小球中被激活。此外，M1 巨噬细胞主要参与 BC 破裂的早期阶段，而 M2 巨噬细胞则参与晚期阶段，并可能有助于新月体的纤维化过程。最后，ANCA-GN 中肾小球细胞的丢失可能是由细胞凋亡介导的。我们的研究结果表明，数字空间分析允许对受疾病过程影响不同的单个肾小球的 mRNA 和蛋白质谱进行比较分析，并确定 ANCA-GN 中的潜在新机制。
