Project description:Chemotherapy, the standard of care treatment for cancer patients with advanced disease, has been increasingly recognised to activate host immune responses to produce durable outcomes. Here, in colorectal adenocarcinoma (CRC) we identify oxaliplatin-induced Thioredoxin Interacting Protein (TXNIP), a MondoA-dependent tumor suppressor gene, as a negative regulator of Growth/Differentiation Factor 15 (GDF15). GDF15 is a negative prognostic factor in CRC and promotes the differentiation of regulatory T cells (Tregs), which inhibit CD8 T cell activation. Intriguingly, multiple models including patient-derived tumor organoids demonstrate that the loss of TXNIP and GDF15 responsiveness to oxaliplatin is associated with advanced disease or chemotherapeutic resistance, with transcriptomic or proteomic GDF15/TXNIP ratios showing potential as a prognostic biomarker. These findings illustrate a potentially common pathway where chemotherapy-induced epithelial oxidative stress drives local immune remodelling for patient benefit, with disruption of this pathway seen in refractory or advanced cases.
Project description:To examine the generality of our finding where the gene expression profile of TXNIP knockout in MDA-MB-231 cells resembles of that Myc overexpression transcriptional program, our lab has generated TXNIP null HCC70 (HCC70:TKO) and MB135 (MB135:TKO) cells. We characterized the gene exrpession programs of these cells by RNA-seq.
Project description:Our RNA sequencing result demonstrated that TXNIP loss increased the levels of Myc-dependent transcription. To determine whether TXNIP regulates global Myc genomic occupancy, we performed Myc ChIP-seq on parental 231 and 231:TKO cells.
Project description:Purpose: To identifiy mRNA changes in wt cone photoreceptors with Txnip overexpression treatment, which improved retinitis pigmentosa (RP) cone survival and visual acuity. Methods: two wt mouse strains, BALB/c and C57BL/6J were injected with AAV-Txnip or AAV-H2BGFP control subretinally at P0. Retinas were dissected out at P21 for BALB/c and P35 for C57BL/6J. 1,000 H2BGFP labeled cones per retina sample were FACS sorted out, and subject for RNA-sequencing. Results: only ~70 genes in P21 BALB/c and 1 genes in C57BL/6J were found differentially expressed with Txnip treatment. Only 1 genes (i.e. Txnip) were in commonly upregulated between the two lists. Conclusions: Txnip seems to be not changing RNA expression much in wt cones. Instead, its major function to rescue RP cones may lay in protein-protein interactions.
Project description:To better understand how TXNIP in the contributes to the poor prognosis of triple-negative breast cancers, our lab has generated TXNIP null MDA-MB-231 cells (231:TKO). We characterized the gene exrpession programs of these cells by RNA-seq. To determine the Myc-dependence of the transcriptional programs of 231:TKO cells, we used an siRNA RNA approach to reduce Myc levels.
Project description:Thioredoxin-interacting protein (TXNIP) is ubiquitously expressed in blood cells, including hematopoietic stem cells (HSCs), monocytes, and platelets. Here we report a novel finding that TXNIP plays a crucial role in megakaryopoiesis and platelet biogenesis via interacting with GATA1, a transcription factor for megakaryocyte-erythroid differentiation. Txnip-/- mice displayed immature megakaryocytes in the bone marrow with thrombocytopenia, which had gotten worse as the mice aged. Transcriptome analysis revealed that the transcriptional activity of GATA1 was significantly enhanced in the Txnip-/- megakaryocyte precursors (MkPs) than wild type (WT) cells. During megakaryopoiesis in ex vivo, Txnip-/- MkPs remained small in cell size with less mitochondrial mass, and more glycolysis for ATP production, as opposed to the normal megakaryocyte maturation. The effects of TXNIP in megakaryocytes were recapitulated in human cord blood CD34+ HSC-derived differentiation. Taken together, this study demonstrates the importance of spatiotemporal expression of TXNIP in platelet biogenesis. We propose for the first time that TXNIP might play a critical role in determining a lineage between megakaryocytes and erythroid cells from a common megakaryocyte-erythroid progenitor via regulation of transcriptional activity of GATA1.
Project description:Purpose: To identifiy mRNA changes in retinitis pigmentosa (RP) cone photoreceptors with Txnip overexpression treatment, which improved RP cone survival and visual acuity. Methods: two RP mouse strains, rd1 and Rho-/-, were injected with AAV-Txnip or AAV-H2BGFP control subretinally at P0. Retinas were dissected out at P21 for rd1 and P90 for Rho-/-. 1,000 H2BGFP labeled cones per retina sample were FACS sorted out, and subject for RNA-sequencing. Results: >1,400 genes in P21 rd1 and >700 genes in Rho-/- were found differentially expressed with Txnip treatment. Conclusions: 25 genes are in common between P21 rd1 and P90 Rho-/- with Txnip treatment. On this list, notably, three mitochondrial Electron Transport Chain (ETC) genes were up-regulated.
Project description:Tissue fibrosis and organ dysfunction are hallmarks of age-related diseases including heart failure, but it remains elusive whether there is a common pathway to induce both events. Through single-cell RNA-seq, spatial transcriptomics, and genetic perturbation, we elucidate that high-temperature requirement A serine peptidase 3 (Htra3) is a critical regulator of cardiac fibrosis and heart failure by maintaining the identity of quiescent cardiac fibroblasts through degrading transforming growth factor-β (TGF-β). Pressure overload downregulates expression of Htra3 in cardiac fibroblasts and activated TGF-β signaling, which induces not only cardiac fibrosis but also heart failure through DNA damage accumulation and secretory phenotype induction in failing cardiomyocytes. Overexpression of Htra3 in the heart inhibits TGF-β signaling and ameliorates cardiac dysfunction after pressure overload. Htra3-regulated induction of spatio-temporal cardiac fibrosis and cardiomyocyte secretory phenotype are observed specifically in infarct regions after myocardial infarction. Integrative analyses of single-cardiomyocyte transcriptome and plasma proteome in human reveal that IGFBP7, which is a cytokine downstream of TGF-β and secreted from failing cardiomyocytes, is the most predictable marker of advanced heart failure. These findings highlight the roles of cardiac fibroblasts in regulating cardiomyocyte homeostasis and cardiac fibrosis through the Htra3-TGF-β-IGFBP7 pathway, which would be a therapeutic target for heart failure.