Project description:Autosomal recessive polycystic kidney disease (ARPKD) is caused by mutations in the PKHD1 gene in both humans and the orthologous PCK rat model. Although ARPKD results solely from PKHD1 mutations, the disease onset and severity are highly variable, indicating that other unknown genetic risk factor(s) modify ARPKD-associated phenotypes. To identify genetic modifiers of ARPKD severity, we created two genetically distinct Pkhd1 congenic rat strains on the Fawn-Hooded Hypertensive (FHH) and the Dahl S (SS) rat backgrounds (denoted FHH.Pkhd1 and SS.Pkhd1, respectively) that harbor the PCK-derived Pkhd1 allele. The FHH.Pkhd1 and SS.Pkhd1 strains had lower renal cyst formation at 30 days-of-age (5±2% and 8±2% cystic, respectively; P<0.001) compared to the PCK kidneys (26±4% cystic), which coincided with significantly reduced kidney weights in the FHH.Pkhd1 and SS.Pkhd1. Liver cyst formation and liver weight did not differ between PCK, FHH.Pkhd1, and SS.Pkhd1. These data indicated that the PCK genome harbors genetic modifier(s) of ARPKD severity that are not present in the FHH and SS genomes. Using high density SNP array genotyping and microarray expression analysis, we identified 50 potential modifiers of ARPKD severity in the PCK rat. Of these candidates, a damaging nonsynonymous variant in Nphp4 stood out as the most likely candidate based on variant segregation, protein modeling, network analysis, and gene ontology. Nphp4 is widely associated with the autosomal recessive cilliopathy and nephronopthisis, but had not been previously implicated in the molecular or cellular pathophysiology of ARPKD. Collectively, these data provide genetic evidence of disease modifier(s) in the PCK model of ARPKD and prioritized multiple candidates, including NPHP4, for further investigation in ARPKD pathogenesis. In this study, we used microarray to analyze transcript expression in the kidneys of 30 day old SD (n=4), PCK (n=4), FHH (n=4), FHH.Pkhd1 (n=4), SS (n=4), and SS.Pkhd1 (n=4). Samples were pooled and the pooled samples were run in triplicate. The 30 day timepoint was chosen because the differences in renal cyst formation between PCK, FHH.Pkhd1, and SS.Pkhd1 were greatest at this timepoint. To account for genetic strain differences that do not contribute to ARPKD severity, gene expression of each cystic rat strain was compared to its parental strain.
Project description:Autosomal recessive polycystic kidney disease (ARPKD) is caused by mutations in the PKHD1 gene in both humans and the orthologous PCK rat model. Although ARPKD results solely from PKHD1 mutations, the disease onset and severity are highly variable, indicating that other unknown genetic risk factor(s) modify ARPKD-associated phenotypes. To identify genetic modifiers of ARPKD severity, we created two genetically distinct Pkhd1 congenic rat strains on the Fawn-Hooded Hypertensive (FHH) and the Dahl S (SS) rat backgrounds (denoted FHH.Pkhd1 and SS.Pkhd1, respectively) that harbor the PCK-derived Pkhd1 allele. The FHH.Pkhd1 and SS.Pkhd1 strains had lower renal cyst formation at 30 days-of-age (5±2% and 8±2% cystic, respectively; P<0.001) compared to the PCK kidneys (26±4% cystic), which coincided with significantly reduced kidney weights in the FHH.Pkhd1 and SS.Pkhd1. Liver cyst formation and liver weight did not differ between PCK, FHH.Pkhd1, and SS.Pkhd1. These data indicated that the PCK genome harbors genetic modifier(s) of ARPKD severity that are not present in the FHH and SS genomes. Using high density SNP array genotyping and microarray expression analysis, we identified 50 potential modifiers of ARPKD severity in the PCK rat. Of these candidates, a damaging nonsynonymous variant in Nphp4 stood out as the most likely candidate based on variant segregation, protein modeling, network analysis, and gene ontology. Nphp4 is widely associated with the autosomal recessive cilliopathy and nephronopthisis, but had not been previously implicated in the molecular or cellular pathophysiology of ARPKD. Collectively, these data provide genetic evidence of disease modifier(s) in the PCK model of ARPKD and prioritized multiple candidates, including NPHP4, for further investigation in ARPKD pathogenesis.
Project description:To facilitate the search for genetic modifiers that modulate ARPKD disease progression and severity, we sought to generate a congenic rat model that carries the PCK Pkhd1 mutation but is resistant to the development of ARPKD. We transferred the Pkhd1 mutation from the PCK rat onto the genetic background of the FHH (Fawn-Hooded Hypertensive) rat. This newly developed strain, called FHH.Pkhd1, showed significant amelioration of renal disease, and delayed onset of biliary abnormalities. To initiate the exploration for genes and pathways that modulate susceptibility to renal cystogenesis, we investigated transcriptional changes in kidneys from PCK, SD, FHH and FHH.Pkhd1 rats by microarray analysis.
Project description:Inflammation is a key component of pathological angiogenesis. Here we induce cornea neovascularisation using sutures placed into the cornea, and sutures are removed to induce a regression phase. We used whole transcriptome microarray to monitor gene expression profies of several genes
Project description:Knee osteoarthritis (KOA), as a degenerative multifactorial disease, affects the quality of life and mental health of patients, and also brings a huge socioeconomic burden. Treating synovitis have shown promise as anti-inflammatory therapeutics in mitigating OA symptoms and disease progression. Here, by analysing synovial single-cell sequencing (scRNA-seq) data from KOA, we found that synovial fibroblasts (FLS) in OA synovium showed a distinct pro-inflammatory phenotype. We collected synovial tissue from patients with clinical OA as well as from healthy donors, and histological examination was consistent with findings in scRNA-seq. Inspired by recent cross-tissue fibroblast lineage studies, we identified by sequencing that healthy FLS in synovial tissues share transcriptome-level similarities with dermal fibroblasts (DFb). Subsequently, we revealed the local as well as systemic distribution of intra-articular injected DFbs by constructing/extracting two types of rat fibroblasts (luciferase DFbs as well as GFP DFbs). The results demonstrate that DFbs can be locally retained in the synovium for up to three weeks following targeted engrafting on it. And intra-articular injection does not result in DFbs migration to vital organs or the occurrence of histological changes in these organs. A rat model of KOA was constructed by anterior cruciate ligament transection (ACLT) in order to study the therapeutic effect of DFbs on KOA. After injection, the rats showed improvement in painful gait. In addition, histological as well as imaging results showed reduced synovitis and improvement in articular cartilage. Finally we verified the protective effect of DFbs on cytokine-stimulated chondrocytes in a co-culture system.