The CCN family member 2 (CCN2 also known as connective tissue growth factor) may behave as a risk biomarker and a potential therapeutic target for renal disease. CCN2 to mice caused sustained renal inflammation. In these mice TGF-neutralizing antibody significantly increased renal expression of the NGAL (a kidney injury biomarker) kidney infiltration 360A iodide by monocytes/macrophages and upregulation of MCP-1 expression. The anti-inflammatory effect of TGF-seems to be mediated by a dysregulation of the systemic Treg immune response shown by decreased levels of circulating CD4+/Foxp3+Treg cells. Our experimental data support the idea that TGF-exerts anti-inflammatory actions in the kidney and suggest that it is not an optimal therapeutic target. 1 Introduction Chronic kidney disease (CKD) is usually a major health problem that has reached epidemic proportions and may lead to end-stage renal disease or early cardiovascular death [1]. Moreover the increasing incidence of diabetes hypertension and obesity will result in future increases in the number of patients with CKD. Available therapy for CKD only delays but does not prevent disease progression. Besides there are still no 360A iodide valid biomarkers that more accurately reflect the severity of the underlying renal histopathological changes and predict CKD progression or death [1]. Among the potential biomarkers and 360A iodide therapeutic targets the CCN family member 2 (CCN2) has emerged as an interesting candidate [2]. CCN2 was initially described as the major platelet derived growth factor-related mitogen secreted 360A iodide by human vascular endothelial cells and named connective tissue growth factor (CTGF) [3]. This matricellular protein is usually a member of the CCN family of secreted cysteine-rich regulatory proteins; therefore the term CCN2 is used as a proposal for uniform nomenclature [4]. CCN2 is usually a developmental gene silenced in the adult kidney and reexpressed during kidney injury [2]. CCN2 levels in plasma or urine have been proposed to behave as risk biomarkers for CKD [5-7] and for cardiac dysfunction in patients exhibiting myocardial fibrosis and chronic heart failure [8]. Initial studies showed that CCN2 contributed to fibrosis [9] and it was proposed as an antifibrotic target [10 11 Experimental studies have shown that inhibition of endogenous CCN2 by antisense oligonucleotides slows disease progression in experimental diabetic nephropathy unilateral ureteral obstruction and nephrectomized TGF-in vivo[21]. 360A iodide 360A iodide Moreover chronic CCN2(IV) administration caused a sustained kidney proinflammatory response mainly characterized by activation of the Th17 immune response [19]. CCN2 as a mediator or coactivator of TGF-mediated profibrotic responses [2 9 11 22 CCN2 overproduction has been proposed to play a major role in pathways that lead to fibrosis [2 11 Indeed the MGC79399 notion that CCN2 is usually a downstream profibrotic mediator of TGF-is the chief operating paradigm in the field but there is no data on the effect of TGF-blockade in CCN2 actionsin vivoblockade in experimental CCN2(IV)-induced renal damage focusing on the regulation of inflammation and the modulation of Th17/Treg responses. 2 Materials and Methods 2.1 Studies Studies were performed in adult male C57BL/6 mice (9-12 weeks aged 20 obtained from Harlan Interfauna Ibérica) and maintained at the local animal facilities under special pathogen free conditions. All procedures on animals were performed according to the international and Instituto de Investigación Sanitaria Fundación Jiménez Díaz Animal Research Committee guidelines. Mice received a single intraperitoneal injection (i.p.) of CCN2(IV) at the dose of 2.5?ng/g of body weight dissolved in saline (= 10 mice) as previously described [17 18 and were studied 10 days later. The purity of CCN2(IV) (obtained from MBL/Peprotech Bionova) was confirmed by MALDI-TOF (not shown). We have previously explained that systemic CCN2(IV) administration caused a sustained inflammatory response in the kidney that peaked at 10 days [20]; therefore this time point was chosen for the experiments. For TGF-neutralization experiments mice were injected with an anti-TGF-pan-specific neutralizing.