JAK2V617F-dependent clonal hematopoiesis drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm
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ABSTRACT: In order to understand the mechanisms responsible for lethal JAK2V617F-dependent aortic disease, we performed RNA sequencing in the aorta of 7-week old Jak2V617F HC-EC and control Jak2WT mice
Project description:JAK2V617F mutation is associated with an increased risk for athero-thrombotic cardiovascular disease, but its role in aortic disease development and complications remains unknown. In a cohort of patients with myeloproliferative neoplasm, JAK2V617F mutation was identified as an independent risk factor for dilation of both the ascending and descending thoracic aorta. Using single-cell RNA-seq, complementary genetically-modified mouse models, as well as pharmacological approaches, we found that JAK2V617F mutation was associated with a pathogenic pro-inflammatory phenotype of perivascular tissue-resident macrophages, which promoted deleterious aortic wall remodeling at early stages, and dissecting aneurysm through the recruitment of circulating monocytes at later stages. Finally, genetic manipulation of tissue-resident macrophages, or treatment with a Jak2 inhibitor, ruxolitinib, mitigated aortic wall inflammation and reduced aortic dilation and rupture. Overall, JAK2V617F mutation drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm.
Project description:JAK2V617F mutation is associated with an increased risk for athero-thrombotic cardiovascular disease, but its role in aortic disease development and complications remains unknown. In a cohort of patients with myeloproliferative neoplasm, JAK2V617F mutation was identified as an independent risk factor for dilation of both the ascending and descending thoracic aorta. Using single-cell RNA-seq, complementary genetically-modified mouse models, as well as pharmacological approaches, we found that JAK2V617F mutation was associated with a pathogenic pro-inflammatory phenotype of perivascular tissue-resident macrophages, which promoted deleterious aortic wall remodeling at early stages, and dissecting aneurysm through the recruitment of circulating monocytes at later stages. Finally, genetic manipulation of tissue-resident macrophages, or treatment with a Jak2 inhibitor, ruxolitinib, mitigated aortic wall inflammation and reduced aortic dilation and rupture. Overall, JAK2V617F mutation drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm.
Project description:Abdominal Aortic Aneurysm (AAA) is a prevalent life-threatening disease, where aortic wall degradation is mediated by accumulated immune cells. Though cytokines regulate inflammation within the aorta, their contribution to AAA via distant alterations, particularly in the control of hematopoietic stem cell (HSC) differentiation remains poorly defined. Here we report a pathogenic role for the interleukin-27 receptor (IL-27R) in AAA as genetic ablation of IL-27R protects mice from the disease development, where the mitigation of AAA is associated with a blunted accumulation of myeloid cells in the aorta due to the attenuation of Ang II-induced HSC expansion. The loss of IL-27R engages transcriptional programs that promote HSCs quiescence and suppresses differentiation decreasing mature myeloid cell production and accumulation in the aorta. Our studies illuminate how a prominent vascular disease can be distantly driven by cytokine dependent regulation of bone marrow precursors.
Project description:To improve our limited understanding of the pathogenesis of thoracic aortic aneurysm (TAA) leading to acute aortic dissection, we used single-cell RNA sequencing to profile disease-relevant transcriptomic changes of aortic cell populations in a well-characterized mouse model of the most commonly diagnosed form of Marfan syndrome (MFS). As result,MFSmod were identified only in the aorta of Fbn1mgR/mgR mice. In situ hybridizations of diagnostic transcripts located MFSmod cells to the intima of Fbn1mgR/mgR aortas. Consistent with angiotensin II type I receptor (At1r) contribution to TAA development, MFSmod cells were absent in the aorta of Fbn1mgR/mgR mice treated with the At1r antagonist losartan. Altogether, our findings indicate that a discrete dynamic alteration of aortic cell identity is associated with dissecting TAA in MFS mice and increased risk of aortic dissection in MFS patients.
Project description:Conducted proteomics on samples from patients with aortic aneurysm and from non-dilated controls. Furthermore, we investigated both patients with bicuspid aortic valves (BAV) and also the more normal tricuspid aortic valves (TAV). The aim was to elucidate the molecular mechanisms behind the higher propensity of BAV patients to develop aorta dilation and consequent aortic aneurysm.
Project description:Conducted proteomics on samples from patients with aortic aneurysm and from non-dilated controls. Furthermore, we investigated both patients with bicuspid aortic valves (BAV) and also the more normal tricuspid aortic valves (TAV). The aim was to elucidate the molecular mechanisms behind the higher propensity of BAV patients to develop aorta dilation and consequent aortic aneurysm.
Project description:We compared the aorta of 6-weeks-old mice (young) with 18-months-old mice (old). Using the publicly available tools Sylamer and DIANA-mirExTra, we identified an enrichment for miR-29 binding sites in the 3'UTR of genes downregulated in the aged aortas. We subsequently showed that inhibition of miR-29 in aged mice prevented dilation of the aorta. aortas of 6 week old and 18 month old mice
Project description:In order to explore the gene expression signature in essential thrombocythemia (ET) patients in relation to JAK2V617F mutational status, expression profiling in circulating granulocytes was performed. Twenty ET were studied by microarray analysis and the results were confirmed by real-time quantitative RT-PCR in 40 ET patients, not receiving cytoreductive treatment. A heterogeneous molecular signature characterized by two main gene expression patterns was found: one with an up-regulation of inflammatory genes related to neutrophil activation and thrombosis, and the other one with significantly lower expression of these genes. Supervised clustering analysis showed 30 genes differentially expressed between JAK2V617F-negative and JAK2V617F-positive ET patients. Among the JAK2V617F-negative, a set of 14 genes (CISH, C13orf18, CCL3, PIM1, MAFF, SOCS3, ID2, GADD45B, KLF5, TNF, LAMB3, HRH4, TAGAP and TRIB1) showed an abnormal expression pattern. In this group of patients CISH, SOCS2, SOCS3 and PIM1 genes, all involved in JAK-STAT signaling pathway, presented a lower expression,. A two-gene predictor model was built comprising FOSB and CISH genes, which were the best discriminators of JAK2V617F status. In conclusion, JAK2V617F-negative ET patients present a characteristic gene expression profile, different from JAK2V617F-positive patients. Other pathways besides JAK-STAT might be implicated in the pathophysiology of JAK2V617F-negative ET patients. Keywords: Disease state analysis
Project description:V617F driver mutation of JAK2 is the leading cause of the Philadelphia-chromosome-negative myeloproliferative neoplasms (MPNs). Loss of Plek2 ameliorated JAK2V617F-induced myeloproliferative phenotypes including erythrocytosis, neutrophilia, thrombocytosis, and splenomegaly, thereby reverting the widespread vascular occlusions and lethality of JAK2V617F knockin mice. To reveal the role of Plek2 in the pathogenesis of JAK2V617F-induced MPNs and the detail mechanisms of its rescue, we performed RNA sequencing to analyze the gene expression profiles change between JAK2V617F/+ Plek2+/+ and JAK2V617F/+ Plek2-/- erythroblasts and hematopoietic stem/progenitor cells.