interleukin-8 and Polycystic-Kidney--Autosomal-Dominant

Autosomal dominant polycystic kidney disease (ADPKD) is a highly prevalent inherited disorder and results in the progressive development of cysts in both kidneys. In recent studies, several cytokines and growth factors secreted by the cyst-lining epithelia were identified to be upregulated and promote cyst growth. According to our previous study, chemokines with a similar amino acid sequence as human interleukin-8 (IL-8) are highly expressed in a rodent model with renal cysts. Therefore, in this study, we focused on whether IL-8 signalling is associated with renal cyst formation, and tested the possibility of IL-8 as a new therapeutic target for ADPKD.. Expression of IL-8 and its receptor were screened either by enzyme linked immunosorbent assay (ELISA) or Western blot. Inhibited IL-8 signalling by antagonist for IL-8 receptor or gene silencing was tested in molecular levels, mainly through Western blot. And cell proliferation was measured by XTT assays. Finally, a three-dimensional culture was performed to understand how IL-8 affected cyst formation, in vitro.. Interleukin-8 secretion and expression of its receptor highly increased in two different human ADPKD cell lines (WT9-7 and WT9-12), compared to normal human renal cortical epithelial cell line. Cell proliferation, which is mediated by IL-8 signal, was inhibited either by an antagonist or siRNA targeting for IL-8 receptor. Finally, a three-dimensional culture showed an alleviation of cystogenesis in vitro, after blocking the IL-8 receptor signals.. These results suggest that IL-8 and its signalling molecules could be new biomarkers and a therapeutic target of ADPKD.

Topics: Cell Proliferation; Cells, Cultured; Humans; Interleukin-8; Polycystic Kidney, Autosomal Dominant; Receptors, Interleukin-8; Signal Transduction

Topics: Animals; Cells, Cultured; Cysts; Disease Models, Animal; Endothelial Cells; Endothelium, Vascular; Humans; Interleukin-8; Liver Diseases; Mice; Mice, Knockout; Polycystic Kidney, Autosomal Dominant; Radiography; Vascular Endothelial Growth Factor A

Autosomal dominant polycystic kidney disease (ADPKD) is a highly prevalent genetic disease that results in cyst formation in kidney and liver. Cytokines and growth factors secreted by the cyst-lining epithelia are positioned to initiate autocrine/paracrine signaling and promote cyst growth. Comparative analyses of human kidney and liver cyst fluids revealed disparate cytokine/growth factor profiles. CXCR2 agonists, including IL-8, epithelial neutrophil-activating peptide (ENA-78), growth-related oncogene-alpha (GRO-alpha), are potent proliferative agents that were found at high levels in liver but not kidney cyst fluids. Liver cysts are lined by epithelial cells derived from the intrahepatic bile duct (i.e., cholangiocytes). In polarized pkd2(WS25/-) mouse liver cyst epithelial monolayers, CXCR2 agonists were released both apically and basally, indicating that they may act both on the endothelial and epithelial cells within or lining the cyst wall. IL-8 and human liver cyst fluid induced cell proliferation of HMEC-1 cells, a human microvascular endothelial cell line, and Mz-ChA1 cells, a human cholangiocyte cell model. IL-8 expression can be regulated by specific stresses. Hypoxia and mechanical stretch, two likely stressors acting on the liver cyst epithelia, significantly increased IL-8 secretion and promoter activity. AP-1, c/EBP, and NF-kappaB were required but not sufficient to drive the stress-induced increase in IL-8 transcription. An upstream element between -272 and -1,481 bp allowed for the stress-induced increase in IL-8 transcription. These studies support the hypothesis that CXCR2 signaling promotes ADPKD liver cyst growth.

Topics: Animals; Cell Hypoxia; Cell Line; Cell Line, Tumor; Cell Polarity; Cell Proliferation; Cell Shape; Cells, Cultured; Chemokine CXCL1; Chemokine CXCL5; Cyst Fluid; Cysts; Endothelial Cells; Epithelial Cells; Humans; Interleukin-8; Kidney; Liver; Liver Diseases; Mice; Mice, Inbred C57BL; Mice, Knockout; Polycystic Kidney, Autosomal Dominant; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Receptors, Interleukin-8B; Signal Transduction; Stress, Mechanical; Transcription, Genetic; Transfection; TRPP Cation Channels

Autosomal dominant polycystic kidney disease (ADPKD) progresses to renal insufficiency in >50% of patients and is characterized by interstitial inflammation and fibrosis in the end stage. In a rat model of ADPKD, monocytes accumulate within the renal interstitium in association with increased levels of monocyte chemoattractant protein-1 (MCP-1) in cyst mural cells and increased excretion of this chemokine into the urine. For determining the extent to which this chemokine is abnormally expressed in patients with ADPKD, a cross-section study was performed of MCP-1 in urine, serum, and cyst fluid and MCP-1 production by mural epithelial cells cultured from the cysts of human patients with ADPKD. Upper boundaries for urinary MCP-1 excretion (>263 pg/mg creatinine) and serum creatinine concentration (>1.5 mg/dl) determined in 19 normal individuals were used to sort 55 ADPKD patients into three groups. In group 1 (n = 13), urine MCP-1 excretion (136 +/- 14 pg/mg creatinine) was not different from normal volunteers (152 +/- 16 pg/mg); serum creatinine levels and urine total protein excretion were normal as well. In group 2 (n = 27), urine MCP-1 excretion was increased (525 +/- 39 pg/mg creatinine), but serum creatinine levels and urine protein excretion were not different from normal. In group 3 (n = 15), urine MCP-1 excretion increased further (1221 +/- 171 pg/mg), serum creatinine levels increased to 4.3 +/- 0.8 mg/dl, and urine protein excretion rose to 0.64 +/- 0.28 mg/mg creatinine. Serum MCP-1 levels of ADPKD patients (84 +/- 9.9 pg/ml; n = 15) did not differ from normal. Levels of MCP-1 much higher than in serum or urine were found in cyst fluids obtained from nephrectomy specimens (range, 767 to 40,860 pg/ml; mean, 6434 +/- 841 pg/ml; n = 73). Polarized, confluent cultures of ADPKD cyst epithelial cells secreted MCP-1 into the apical fluid to levels eightfold greater than in the basolateral medium. Similar results were obtained with tubule epithelial cells cultured from normal human renal cortex. On the basis of these results, it is concluded that urinary excretion of MCP-1 is increased in the majority of adult patients with ADPKD and that the source of some of this chemokine may be the mural epithelium of cysts. Furthermore, it seemed that urinary MCP-1 excretion may have increased in these ADPKD patients before appreciable increases in serum creatinine concentration or urine protein excretion were detected. It is reasonable to include urine MCP-1 excre

Topics: Adult; Aged; Biomarkers; Blotting, Western; Cells, Cultured; Chemokine CCL2; Chemokine CCL7; Cyst Fluid; Cytokines; Epithelial Cells; Female; Humans; Interleukin-8; Kidney Cortex; Male; Middle Aged; Monocyte Chemoattractant Proteins; Polycystic Kidney, Autosomal Dominant; Tumor Necrosis Factor-alpha

To elucidate the pathogenetic mechanism of renal parenchymal injury in autosomal dominant polycystic kidney disease (ADPKD) patients, typically characterized by renal cystic changes paralleled by interstitial inflammation and gradual fibrotic changes, the role of selected inflammatory mediators was evaluated in a group of ADPKD patients with normal glomerular filtration rate. The plasma concentrations of IL-6, IL-8, ICAM-1 and VCAM-1 (which may reflect systemic response to inflammation/infection) were increased in the ADPKD patient group. Coupled with decreased urinary excretion of the IL-1 receptor antagonist (which exerts an anti-inflammatory role), these results suggest that even in overt infection free status, the proinflammatory system is more activated and anti-inflammatory defence system weakened in ADPKD subjects. Our data support the current view that cytokines are candidate contributors to pathogenesis of ADPKD.

Topics: Adult; Cytokines; Female; Humans; Intercellular Adhesion Molecule-1; Interleukin-1; Interleukin-6; Interleukin-8; Male; Polycystic Kidney, Autosomal Dominant; Vascular Cell Adhesion Molecule-1

Topics: Adult; Creatinine; Cytokines; Female; Humans; Intercellular Adhesion Molecule-1; Interleukin 1 Receptor Antagonist Protein; Interleukin-6; Interleukin-8; Male; Polycystic Kidney, Autosomal Dominant; Sialoglycoproteins; Vascular Cell Adhesion Molecule-1