Project description:The goal of this study was to identify genome-wide chromatin accessibility changes caused by podocyte specific overexpression of KLF6 in STZ + UNX induced diabetic mouse model.
Project description:The goal of this study was to identify transcriptomic changes mediated by KLF6 induction in the setting of STZ-induced diabetic kidney disease
Project description:Podocytes play an important filtration role in the kidney. We examined culture condition for efficient podocyte induction and established a method to selectively induce podocytes from human iPS cells. To understand how expression profiles of human iPS cell-derived podocytes were close to that in vivo, we isolated human adult podocytes for human adult kidney. Purified RNAs from human iPS cells, nephron progenitor cells, human immortalized podocyte cell line, human iPS cell-derived podocytes, and sorted human adult podocytes were analyzed by RNA-seq.
Project description:Like many cell types, the mechanisms and pathways underlying healthy aged-related changes to podocytes are not fully understood. Candidate pathways include oxidative stress, epigenetic changes, senescence, sirtuins, reduced autophagy and increased apoptosis, although detailed mechanisms underlying each pathway is not well defined. While detailed gene analysis has been undertaken on whole portions of the aging kidney, transcriptomic changes specific to podocytes in the aged kidney are not known. To address this, we used an inducible podocyte specific reporter mouse in which a cohort of podocytes are permanently labeled over the life time of the animal. RNA-seq was then used to measure transcriptional changes in genes in labeled podocytes in mice with advanced age, compared to podocytes from a cohort of young reporter mice.
Project description:In this work, we isolated and characterized a novel cell population derived from human amniotic fluid cells (hAKPC-P), and we differentiated them into podocytes. We used microarrays to study global changes in gene expression before and after differentiation in hAKPC-P and human immortalized podocytes (hIPod, positive control) and performed a detailed comparison between the different populations hAKPC-P were isolated by FACS sorting from the total human amniotic fluid cell population and differentiated into podocytes using VRADD media. Morphological, phenotypical and functional analysis were performed to assess their differentiation. To confirm the results, cells were compared with human conditionally immortalized podocytes.
Project description:Gene-expression profiles of liver and hepatocellular carcinoma induced by diethylnitrosamine (DEN) in KLF6 +/- and wild type KLF6 mice. Inactivation of the KLF6 tumor suppressor is common in HCC due to hepatitis C virus (HCV), consistent with its anti-proliferative activity in HCC-derived cell lines and in hepatocytes of transgenic mice. We have evaluated the impact of KLF6 depletion on human HCC and experimental hepatocarcinogenesis. In patients with surgically resected HCC, those with significantly reduced tumor expression of KLF6 had a significantly decreased survival. We modeled this event in KLF6 +/- mice, which displayed significantly more tumorigenicity than KLF6 +/+ animals in response to the hepatic carcinogen DEN, associated with recapitulation of gene signatures in both surrounding tissue and tumors that are associated with aggressive human HCCs. In DNA microarrays, mdm2 mRNA expression was increased in tumors from KLF6 +/- compared to KLF6 +/+ mice, which was validated by realtime qPCR and Western blot in both human HCC and DEN-induced murine tumors. Moreover, chromosomal immunoprecipitation and co-transfection assays established the P2 intronic promoter of mdm2 as a bona fide transcriptional target repressed by KLF6. Whereas KLF6 over-expression in HCC cell lines led to reduced MDM2 levels and increased p53 protein and transcriptional activity, reduction in KLF6 by siRNA led to increased MDM2 and reduced p53. Our findings indicate that KLF6 deficiency contributes significantly to the carcinogenic milieu in human and murine HCC, and uncover a novel tumor suppressor activity of KLF6 in HCC, by linking its transcriptional repression of MDM2 to stabilization of p53. Keywords: Liver, Hepatocellular carcinoma, Expression array, Exon array, Affymetrix KLF6 +/- mice were previously generated by homologous recombination in which exon 2 was targeted using an 11-kb targeting construct, and replaced with neomycin/lacZ cassette. After selection with neomycin, the ES clones were injected into C57BL/6 mouse blastocysts and implanted into pseudo pregnant females; two lines of KLF6 +/- mice were generated from the resulting chimeric animals (Blood 107;1357, Oncogene 26;4428). Whereas KLF6 -/- mice are embryonic lethal, KLF6 +/- animals had no demonstrable abnormalities in the absence of any stressor. Male KLF6 +/- mice were bred with wild type C57BL/6 to generate mixed litters of KLF6 +/- and KLF6 +/+ animals. Progeny were genotyped using PCR-amplified tail DNA, using primers as previously described (Oncogene 26;4428). Amplified fragments were separated on a 2.5% agarose gel, revealing bands of ~200 bp (wild type KLF6) and ~100 bp (Neo), as expected. At 2 weeks of age, KLF6 +/+ and KLF6 +/- mice were injected intraperitoneally with either a single dose of diethyl nitrosamine (DEN), 5 µg/g body weight in 100 µl of saline, or vehicle alone. Vehicle and DEN-treated mice were maintained on standard chow, and then sacrificed 3, 6 or 9 months later. At the time of sacrifice the animals were weighed, and blood and liver samples were harvested for analysis and tumor quantification.
Project description:Gene-expression profiles of liver and hepatocellular carcinoma induced by diethylnitrosamine (DEN) in KLF6 +/- and wild type KLF6 mice. Inactivation of the KLF6 tumor suppressor is common in HCC due to hepatitis C virus (HCV), consistent with its anti-proliferative activity in HCC-derived cell lines and in hepatocytes of transgenic mice. We have evaluated the impact of KLF6 depletion on human HCC and experimental hepatocarcinogenesis. In patients with surgically resected HCC, those with significantly reduced tumor expression of KLF6 had a significantly decreased survival. We modeled this event in KLF6 +/- mice, which displayed significantly more tumorigenicity than KLF6 +/+ animals in response to the hepatic carcinogen DEN, associated with recapitulation of gene signatures in both surrounding tissue and tumors that are associated with aggressive human HCCs. In DNA microarrays, mdm2 mRNA expression was increased in tumors from KLF6 +/- compared to KLF6 +/+ mice, which was validated by realtime qPCR and Western blot in both human HCC and DEN-induced murine tumors. Moreover, chromosomal immunoprecipitation and co-transfection assays established the P2 intronic promoter of mdm2 as a bona fide transcriptional target repressed by KLF6. Whereas KLF6 over-expression in HCC cell lines led to reduced MDM2 levels and increased p53 protein and transcriptional activity, reduction in KLF6 by siRNA led to increased MDM2 and reduced p53. Our findings indicate that KLF6 deficiency contributes significantly to the carcinogenic milieu in human and murine HCC, and uncover a novel tumor suppressor activity of KLF6 in HCC, by linking its transcriptional repression of MDM2 to stabilization of p53. Keywords: Liver, Hepatocellular carcinoma, Expression array, Exon array, Affymetrix
Project description:We examine the role of Klf6 in oligodendrocyte progenitor cells and determine that Klf6 acts in part through direct regulation of gp130 signaling and nuclear import via importin-α5 (Impα5), a key controller of nuclear trafficking. Examination of Klf6 DNA binding in two different stages of differentiation
Project description:Analysis of gene expression changes in differentiated human podocytes treated with the serum from patients with (DKD+) or without (DKD-) diabetic kidney disease when compared to normal subjects (C). The hypothesis is that the three groups can be distinghed by their differential gene expression pattern. The results obtained revealed important information regarding differences in gene expression in human podocytes treated with the serum from patients with (DKD+) or without (DKD-) diabetic kidney disease when compared to normal subjects (C). Human podocytes were contacted with the serum from patients with diabetes and kidney disease (DKD+) or without kidney disease (DKD-) and compared to normal human podocytes contacted with serum from patients without diabetes (C).