[101, 102] It is unknown whether MCP-1 levels buy Tyrosine Kinase Inhibitor Library would increase with increasing PC2 expression, or whether MCP-1 levels are diminished by the cystoprotein defect per se. Nonetheless it is clear from this experiment

that cystoproteins can directly influence the expression of inflammatory genes. In contrast, some studies suggest that genetic mutations do not directly instigate the production of inflammatory factors. For example, Zheng et al. observed no differences in MCP-1 concentration between cultured normal human kidney and ADPKD cells,[82] suggesting that MCP-1 production is not directly caused by Pkd1/2 defects. Rather, genetic mutations may increase the susceptibility to inflammation, but only following an injurious event. Prasad et al. induced unilateral IRI in Pkd2 heterozygous and wild-type mice, observing

that although Pkd2 mRNA expression was increased following IRI in both genotypes, it was consistently lower in heterozygotes selleck inhibitor compared with wild-types.[103] Two days post-IRI, the numbers of F4/80-positive macrophages and myeloperoxidase-positive neutrophils per mm2 were significantly higher in heterozygous than in wild-type injured kidneys. Cytokine assays of the injured tissue revealed increased IL-1β and CxCl1 protein in heterozygotes compared with wild-types, suggesting that Pkd2 gene dosage influences cytokine release and inflammatory cell recruitment. Notably, prior to IRI, inflammatory cell numbers were not significantly different between heterozygotes and wild-types. This suggests that Pkd2 heterozygosity predisposes the kidney to greater inflammatory response following injury, but alone is insufficient to instigate inflammation or cystogenesis.[103] It is then interesting to consider whether other genes, apart from Pkd1/2 and Pkhd1, can influence inflammation in PKD. Song et al. performed global gene analysis of human PKD1 renal cysts, and found that among the 100 most upregulated gene sets identified, Methane monooxygenase 11 were

associated with the JAK-STAT pathway, and three were related to NF-κB signalling.[104] The NF-κB proteins regulate the transcription of a variety of genes, including those involved in growth, apoptosis, and inflammation.[105, 106] The products of inflammatory genes controlled by NF-κB include TNF-α, IL-1α and β, IL-6, Ccl3, Ccl4, and MCP-1.[106] NF-κB proteins such as p65 normally reside in the cytoplasm.[105] Upon activation of the system by a stimulus (e.g. TNF-α), these proteins undergo phosphorylation, translocate to the nucleus and activate transcription.[105] Accordingly, several studies have investigated the potential role of NF-κB in mediating PKD. Qin et al.