Poosti Fariba, Bansal Ruchi, Yazdani Saleh, Prakash Jai, Post Eduard, Klok Pieter, van den Born Jacob, de Borst Martin H, van Goor Harry, Poelstra Klaas, Hillebrands Jan-Luuk
*Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
*Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands.
FASEB J. 2015 Mar;29(3):1029-42. doi: 10.1096/fj.14-258459. Epub 2014 Dec 2.
Renal fibrosis leads to end-stage renal disease demanding renal replacement therapy because no adequate treatment exists. IFN-γ is an antifibrotic cytokine that may attenuate renal fibrosis. Systemically administered IFN-γ causes side effects that may be prevented by specific drug targeting. Interstitial myofibroblasts are the effector cells in renal fibrogenesis. Here, we tested the hypothesis that cell-specific delivery of IFN-γ to platelet-derived growth factor receptor β (PDGFRβ)-expressing myofibroblasts attenuates fibrosis in an obstructive nephropathy [unilateral ureteral obstruction (UUO)] mouse model. PEGylated IFN-γ conjugated to PDGFRβ-recognizing peptide [(PPB)-polyethylene glycol (PEG)-IFN-γ] was tested in vitro and in vivo for antifibrotic properties and compared with free IFN-γ. PDGFRβ expression was >3-fold increased (P < 0.05) in mouse fibrotic UUO kidneys and colocalized with α-smooth muscle actin-positive (SMA(+)) myofibroblasts. In vitro, PPB-PEG-IFN-γ significantly inhibited col1a1, col1a2, and α-SMA mRNA expression in TGF-β-activated NIH3T3 fibroblasts (P < 0.05). In vivo, PPB-PEG-IFN-γ specifically accumulated in PDGFRβ-positive myofibroblasts. PPB-PEG-IFN-γ treatment significantly reduced renal collagen I, fibronectin, and α-SMA mRNA and protein expression. Compared with vehicle treatment, PPB-PEG-IFN-γ preserved tubular morphology, reduced interstitial T-cell infiltration, and attenuated lymphangiogenesis (all P < 0.05) without affecting peritubular capillary density. PPB-PEG-IFN-γ reduced IFN-γ-related side effects as manifested by reduced major histocompatibility complex class II expression in brain tissue (P < 0.05 vs. free IFN-γ). Our findings demonstrate that specific targeting of IFN-γ to PDGFRβ-expressing myofibroblasts attenuates renal fibrosis and reduces systemic adverse effects.
肾纤维化会导致终末期肾病，由于缺乏有效的治疗方法，患者需要进行肾脏替代治疗。干扰素-γ（IFN-γ）是一种抗纤维化细胞因子，可能会减轻肾纤维化。全身给药的IFN-γ会产生副作用，而通过特定的药物靶向作用或许可以预防这些副作用。间质肌成纤维细胞是肾纤维化形成过程中的效应细胞。在此，我们验证了以下假说：将IFN-γ细胞特异性地递送至表达血小板衍生生长因子受体β（PDGFRβ）的肌成纤维细胞，可减轻梗阻性肾病[单侧输尿管梗阻（UUO）]小鼠模型中的纤维化。我们在体外和体内测试了与识别PDGFRβ的肽偶联的聚乙二醇化IFN-γ[（PPB）-聚乙二醇（PEG）-IFN-γ]的抗纤维化特性，并将其与游离IFN-γ进行比较。在小鼠纤维化的UUO肾脏中，PDGFRβ的表达增加了3倍以上（P<0.05），且与α-平滑肌肌动蛋白阳性（SMA(+)）的肌成纤维细胞共定位。在体外，PPB-PEG-IFN-γ显著抑制了转化生长因子-β激活的NIH3T3成纤维细胞中col1a1、col1a2和α-SMA的mRNA表达（P<0.05）。在体内，PPB-PEG-IFN-γ特异性地聚集在PDGFRβ阳性的肌成纤维细胞中。PPB-PEG-IFN-γ治疗显著降低了肾脏中I型胶原蛋白、纤连蛋白以及α-SMA的mRNA和蛋白表达。与载体治疗相比，PPB-PEG-IFN-γ保留了肾小管形态，减少了间质T细胞浸润，并减轻了淋巴管生成（均P<0.05），且不影响肾小管周围毛细血管密度。PPB-PEG-IFN-γ减少了IFN-γ相关的副作用，表现为脑组织中主要组织相容性复合体II类分子的表达降低（与游离IFN-γ相比，P<0.05）。我们的研究结果表明，将IFN-γ特异性靶向至表达PDGFRβ的肌成纤维细胞可减轻肾纤维化并减少全身不良反应。
