Autoimmune diseases, such as type 1 diabetes (T1D) and Hashimoto's thyroiditis (HT), are often studied from an immune perspective with less focus on the target tissue responses. Target tissues, howeve Show more
Autoimmune diseases, such as type 1 diabetes (T1D) and Hashimoto's thyroiditis (HT), are often studied from an immune perspective with less focus on the target tissue responses. Target tissues, however, are key to disease and engage in a harmful crosstalk with the immune system contributing to their own destruction. We presently integrated transcriptomic data from the target tissues of six autoimmune/inflammatory diseases affecting β-cells (T1D and type 2 diabetes), thyroid (HT), brain (multiple sclerosis and Alzheimer's disease) or the joints (rheumatoid arthritis), using both bulk and single-cell/nucleus RNA-sequencing (sc/snRNA-seq) approaches. Common upregulated pathways were associated with innate/adaptive immunity, antigen presentation and interferon (IFN) signaling. The role of IFNs was confirmed by RNA-seq in human insulin-producing EndoC-βH1 cells and stem cell-derived thyroid follicle cells exposed to IFNα or IFNγ. Commonly upregulated inflammatory gene signatures were explored, and fibroblast growth factor receptor (FGFR) inhibitors emerged as a potential strategy to counteract these inflammatory transcriptional signatures. The effects of the FGFR1 inhibitor PD173074 on IFN-induced immune related genes were evaluated in EndoC-βH1 cells, stem cell-derived islets and adult human islets. We validated the FGFR inhibitor PD173074 as a promising drug for preserving expression of β-cell protective genes (PDL1 and HLA-E) while reducing HLA class I expression and β-cell recognition by diabetogenic pre-proinsulin-specific CD8 Show less
The Suv39h1 and Suv39h2 H3K9 histone methyltransferases (HMTs) have a conserved role in the formation of constitutive heterochromatin and gene silencing. Using a transgenic mouse model system we demon Show more
The Suv39h1 and Suv39h2 H3K9 histone methyltransferases (HMTs) have a conserved role in the formation of constitutive heterochromatin and gene silencing. Using a transgenic mouse model system we demonstrate that elevated expression of Suv39h1 increases global H3K9me3 levels in vivo. More specifically, Suv39h1 overexpression enhances the imposition of H3K9me3 levels at constitutive heterochromatin at telomeric and major satellite repeats in primary mouse embryonic fibroblasts. Chromatin compaction is paralleled by telomere shortening, indicating that telomere length is controlled by H3K9me3 density at telomeres. We further show that increased Suv39h1 levels result in an impaired clonogenic potential of transgenic epidermal stem cells and Ras/E1A transduced transgenic primary mouse embryonic fibroblasts. Importantly, Suv39h1 overexpression in mice confers resistance to a DMBA/TPA induced skin carcinogenesis protocol that is characterized by the accumulation of activating H-ras mutations. Our results provide genetic evidence that Suv39h1 controls telomere homeostasis and mediates resistance to oncogenic stress in vivo. This identifies Suv39h1 as an interesting target to improve oncogene induced senescence in premalignant lesions. Show less