Browsing by Subject "DNMT3A"

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    Clonal hematopoiesis driven by mutated DNMT3A promotes inflammatory bone loss
    (Elsevier, 2024) Wang, Hui; Divaris, Kimon; Pan, Bohu; Li, Xiaofei; Lim, Jong-Hyung; Saha, Gundappa; Barovic, Marko; Giannakou, Danai; Korostoff, Jonathan M.; Bing, Yu; Sen, Souvik; Moss, Kevin; Wu, Di; Beck, James D.; Ballantyne, Christie M.; Natarajan, Pradeep; North, Kari E.; Netea, Mihai G.; Chavakis, Triantafyllos; Hajishengallis, George; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public Health
    Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H. Partial transplantation with Dnmt3aR878H/+ bone marrow (BM) cells resulted in clonal expansion of mutant cells into both myeloid and lymphoid lineages and an elevated abundance of osteoclast precursors in the BM and osteoclastogenic macrophages in the periphery. DNMT3A-driven clonal hematopoiesis in recipient mice promoted naturally occurring periodontitis and aggravated experimentally induced periodontitis and arthritis, associated with enhanced osteoclastogenesis, IL-17-dependent inflammation and neutrophil responses, and impaired regulatory T cell immunosuppressive activity. DNMT3A-driven clonal hematopoiesis and, subsequently, periodontitis were suppressed by rapamycin treatment. DNMT3A-driven CHIP represents a treatable state of maladaptive hematopoiesis promoting inflammatory bone loss.
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    Rapid development of myeloproliferative neoplasm in mice with Ptpn11D61Y mutation and haploinsufficient for Dnmt3a
    (Impact Journals, 2017-12-26) Deng, Lisa; Richine, Briana M.; Virts, Elizabeth L.; Jideonwo-Auman, Victoria N.; Chan, Rebecca J.; Kapur, Reuben; Pediatrics, School of Medicine
    PTPN11 gain-of-function mutation is the most common mutation found in patients with juvenile myelomonocytic leukemia and DNMT3A loss occurs in over 20% of acute myeloid leukemia patients. We studied the combined effect of both Ptpn11 gain-of-function mutation (D61Y) and Dnmt3a haploinsufficiency on mouse hematopoiesis, the presence of which has been described in both juvenile myelomonocytic leukemia and acute myeloid leukemia patients. Double mutant mice rapidly become moribund relative to any of the other genotypes, which is associated with enlargement of the spleen and an increase in white blood cell counts. An increase in the mature myeloid cell compartment as reflected by the presence of Gr1+Mac1+ cells was also observed in double mutant mice relative to any other group. Consistent with these observations, a significant increase in the absolute number of granulocyte macrophage progenitors (GMPs) was seen in double mutant mice. A decrease in the lymphoid compartment including both T and B cells was noted in the double mutant mice. Another significant difference was the presence of extramedullary erythropoiesis with increased erythroid progenitors in the spleens of Dnmt3a+/-;D61Y mice relative to other groups. Taken together, our results suggest that the combined haploinsufficiency of Dnmt3a and presence of an activated Shp2 changes the composition of multiple hematopoietic lineages in mice relative to the individual heterozygosity of these genes.