Project description:Cardiac fibrosis, is a common pathophysiologic process in nearly all heart diseases, leading to cardiac dysfunction and heart failure subsequently. The transition of cardiac fibroblasts (CFs) to a myofibroblast state underlies the cardiac fibrotic response, and this process is accompanied by changes in the cardiac mechanical environment. Mechanical forces play a central role in the initiation and propagation of fibrosis, resulting in further ECM deposition, crosslinking and reorganization, leading to adverse ventricular remodeling. However, the key factors regulating mechanotransduction during cardiac fibrosis remain unknown. Here we discovered that transcription factor activating enhancer-binding protein 4 (Tfap4) regulates CF migration and proliferation. Further investigation revealed that Tfap4 correlates with heart disease and is significantly upregulated in the fibrotic hearts. We demonstrated that Tfap4 overexpression stimulated CF activation, whereas Tfap4 knockdown resulted in the opposite effect. In addition, we also knocked down Tfap4 in primary human CF (HCFs) with consistent results. Silence of Tfap4 by lentivirus carrying Tfap4 shRNA markedly enhanced functional improvement and scar size reduction in myocardial infarction (MI) mice. Mechanistically, we found that Tfap4 exerts pro-fibrotic function by regulating mechanical stress. Unexpectedly, we found that Tfap4 is a regulator of mechanosensors, Itga11 and Piezo2, thereby involved in mechanotransduction that acts as a bistable switch for the CF phenotypic transition associated with cardiac fibrosis. Taken together, our study revealed that Tfap4 plays an important role in cardiac fibrosis.
Project description:Cystic Fibrosis Related Diabetes (CFRD), the main co-morbidity in Cystic Fibrosis (CF), is associated with higher rates of lung function decline. We hypothesize that airway epithelial barrier function is impaired in CF and is further exacerbated under hyperglycemia, worsening pulmonary outcomes. Using 16HBE cells as a model cell line, we studied the effects of hyperglycemia in airway epithelial barrier function. Results show increased paracellular dye flux in CF cells in response to insulin treatment under hyperglycemia, suggesting impaired barrier integrity. Gene expression experiments identified Claudin-4 (CLDN4) as a key tight junction protein dysregulated in CF cells. Further investigation into CLDN4 protein localization by confocal microscopy showed that CLDN4 was tightly localized at tight junctions in WT cells and localization did not change under hyperglycemia. ln contrast, CLDN4 was less well-localized in CF cells at normal glucose and localization was worsened in CF cells conditioned to hyperglycemia. Treatment with highly effective modulator compounds (ETI) reversed this trend, and CFTR rescue by ETI in CF cells was not affected by insulin treatment or hyperglycemia. Bulk RNA sequencing showed differences in transcriptional responses in CF compared to WT cells under normal or high glucose, highlighting PTPRG as a promising target for further investigation.
Project description:Mutations in CFTR have been shown to alter the immune response of macrophages, for example, by reducing the ability of macrophages to phagocytose and kill bacteria. This contributes to chronic bacterial infection and inflammation in the lungs, which leads to significant morbidity and mortality in cystic fibrosis (CF). Extracellular vesicles (EVs) are secreted by a variety of cell types in the lungs and participate in the host immune response to bacterial infection. However, nothing is known about the effect of EVs secreted by CF airway epithelial cells (AEC) on CF macrophages. Therefore, we examined the effect of EVs secreted by primary CF AEC on CF monocyte derived macrophages (MDM) and compared it with the effect of EVs secreted by wild type (WT) AEC on WT MDM. EVs increased pro-inflammatory cytokine secretion and enhanced the expression of numerous innate immune genes in WT MDM. However, the response of CF MDM to EVs was significantly attenuated compared to WT MDM, a difference that was also observed when EVs were isolated from WT and CF AEC exposed to Pseudomonas aeruginosa. Attenuated responses by CF MDM can be attributed to defects in the CF macrophages themselves rather than differences between CF and WT EVs, because EVs secreted by CF AEC or WT AEC elicited similar cytokine secretion by CF MDM. EVs secreted by P. aeruginosa exposed AEC resulted in the upregulation of immune response genes and increased secretion of pro-inflammatory cytokines, chemoattractants and chemokines involved in tissue repair by WT MDM, whereas the response of CF MDM was attenuated by comparison. To our knowledge, this is the first study examining the effect of EVs secreted by CF AEC on CF MDM, and it demonstrates that the Phe508del mutation in CFTR attenuates the innate immune response of MDM to EVs.
Project description:Many lymphoid malignancies arise from deregulated c-MYC expression in cooperation with additional genetic lesions. While many of these cooperative genetic lesions have been discovered and their functions characterised, DNA sequence data of primary patient samples suggest that many more do exist. However, the nature of their contributions to c-MYC driven lymphomagenesis have not yet been investigated. We identified TFAP4 as a potent suppressor of c-MYC driven lymphoma development in a previous genome-wide CRISPR knockout screen in primary cells in vivo. CRISPR deletion of TFAP4 in Eµ-MYC transgenic haematopoietic stem and progenitor cells (HSPCs) and transplantation of these manipulated HSPCs into lethally irradiated animals significantly accelerated c-MYC-driven lymphoma development. Interestingly, TFAP4 deficient Eµ-MYC lymphomas all arose at the pre-B cell stage of B cell development. This observation prompted us to characterise the transcriptional profile of pre-B cells from pre-leukaemic mice transplanted with Eµ-MYC/Cas9 HSPCs that had been transduced with sgRNAs targeting TFAP4. This analysis revealed that TFAP4 deletion reduced expression of several master regulators of B cell differentiation, such as Spi1, SpiB and Pax5, which are direct target genes of both TFAP4 and MYC. We therefore conclude that loss of TFAP4 leads to a block in differentiation during early B cell development, thereby accelerating c-MYC-driven lymphoma development.
Project description:We did bulk RNA sequencing in newborn cystic fibrosis (CF) and non-CF pig kidney. We compared kidney gene expression profiling between non-CF and CF pigs. RNA sequencing results showed that there is not significant difference between non-CF and CF in terms of gene expression, suggesting that CFTR knockout does not affect kidney development in newborn pigs.
Project description:We analyed the gene expression profiles after knocking down MYCN or TFAP4. Results showed that transcription factor MYCN and TFAP4 commonly regulats a subset of genes that may contribute to neuroblastoma cells proliferation and migration.
Project description:TFAP4 scored strongly in our screen for MSLN CAR T cell resistance; to interogate its function, we performed RNAseq following TFAP4 knockdown and overexpression in HupT3 pancreatic cancer cells.
Project description:A small-scale whole genome microarray study of gene expression in human native nasal epithelial cells from F508del-CFTR homozygous CF patients and non-CF controls. We used the custom designed Affymetrix HsAirwaya520108F Arrays to compare gene expression in 5 CF and 5 non CF nasal epithelial cell samples. We analysed a total of 10 samples (5 CF and 5 non CF). The CF group contained 2 males and 3 females, with an average age of 14 years and an average of 6% inflammatory cells per sample, and the non CF group contained 3 males and 2 females with an average age of 14.8 years and an average of 4.7% inflammatory cells.
Project description:A small-scale whole genome microarray study of gene expression in human native nasal epithelial cells from F508del-CFTR homozygous CF patients and non-CF controls. We used the custom designed Affymetrix HsAirwaya520108F Arrays to compare gene expression in 5 CF and 5 non CF nasal epithelial cell samples.