Zhang Xiaolan, Rovin Brad H
Department of Internal Medicine, Ohio State University, Columbus, OH, USA.
Biochim Biophys Acta. 2010 Dec;1800(12):1262-7. doi: 10.1016/j.bbagen.2010.08.005. Epub 2010 Aug 27.
A previous urine proteomic analysis from our laboratory suggested that hepcidin may be a biomarker for lupus nephritis flare. Immunohistochemical staining of kidney biopsies from lupus patients showed that hepcidin was expressed by infiltrating renal leukocytes. Here we investigated whether inflammatory cytokines relevant to the pathogenesis of lupus nephritis and other glomerular diseases regulate hepcidin expression by human monocytes.
Human CD14+ monocytes were incubated with interferon alpha (IFNα), interferon gamma (IFNγ), interleukin-6 (IL6), interleukin-1 beta (IL1β), monocyte chemotactic factor-1 (MCP1), or tumor necrosis factor alpha (TNFα). Hepcidin expression was examined by real-time PCR and enzyme immunoassay.
Monocyte hepcidin mRNA increased during adherence to the tissue culture wells, reaching a level 150-fold higher than baseline within 12 h of plating. After accounting for the effects of adhesion, monocytes showed time and dose-dependent up-regulation of hepcidin mRNA upon treatment with IFNα or IL6. One hour of incubation with IFNα or IL6 increased hepcidin mRNA 20 and 80-fold, respectively; by 24 h the mRNA remained 5- and 2.4-fold higher than baseline. IL1β, IFNγ, and MCP-1 did not affect monocyte hepcidin expression. TNFα inhibited hepcidin induction by IL6 in monocytes by 44%. After 24 h of treatment with IFNα or IL6, immunoreactive hepcidin production by monocytes increased 3- and 2.6-fold, respectively.
Human monocytes produce hepcidin in response to adhesion and the pro-inflammatory cytokines IFNα and IL6.
The appearance of hepcidin in the kidneys or urine during glomerular diseases may be from infiltrating monocytes induced to express hepcidin by adherence and exposure to pro-inflammatory cytokines found in the renal milieu.
我们实验室之前的一项尿液蛋白质组学分析表明，铁调素可能是狼疮性肾炎发作的生物标志物。对狼疮患者肾脏活检组织进行免疫组化染色显示，浸润的肾白细胞表达铁调素。在此，我们研究了与狼疮性肾炎及其他肾小球疾病发病机制相关的炎性细胞因子是否调节人单核细胞中铁调素的表达。
将人CD14+单核细胞与α干扰素（IFNα）、γ干扰素（IFNγ）、白细胞介素-6（IL6）、白细胞介素-1β（IL1β）、单核细胞趋化因子-1（MCP1）或肿瘤坏死因子α（TNFα）一起孵育。通过实时PCR和酶免疫测定法检测铁调素的表达。
单核细胞在贴壁于组织培养孔的过程中铁调素mRNA增加，接种后12小时内达到比基线水平高150倍的水平。在考虑黏附作用的影响后，单核细胞在用IFNα或IL6处理后显示出铁调素mRNA的时间和剂量依赖性上调。与IFNα或IL6孵育1小时分别使铁调素mRNA增加20倍和80倍；到24小时，mRNA仍比基线水平高5倍和2.4倍。IL1β、IFNγ和MCP-1不影响单核细胞铁调素的表达。TNFα抑制单核细胞中IL6诱导的铁调素生成44%。在用IFNα或IL6处理24小时后，单核细胞产生的免疫反应性铁调素分别增加3倍和2.6倍。
人单核细胞在黏附以及促炎细胞因子IFNα和IL6作用下产生铁调素。
在肾小球疾病期间，肾脏或尿液中铁调素的出现可能源于浸润的单核细胞，这些单核细胞因黏附并暴露于肾脏环境中发现的促炎细胞因子而被诱导表达铁调素。
