TY - JOUR AU - Minakawa, Keiji AU - Yokokawa, Tetsuro AU - Ueda, Koki AU - Nakajima, Osamu AU - Misaka, Tomofumi AU - Kimishima, Yusuke AU - Wada, Kento AU - Tomita, Yusuke AU - Miura, Saori AU - Sato, Yuka AU - Mimura, Kosaku AU - Sugimoto, Koichi AU - Nakazato, Kazuhiko AU - Nollet, Kenneth E. AU - Ogawa, Kazuei AU - Ikezoe, Takayuki AU - Hashimoto, Yuko AU - Takeishi, Yasuchika AU - Ikeda, Kazuhiko PY - 2021 DA - 2021/03/30 TI - Myeloproliferative neoplasm-driving Calr frameshift promotes the development of pulmonary hypertension in mice JO - Journal of Hematology & Oncology SP - 52 VL - 14 IS - 1 AB - Frameshifts in the Calreticulin (CALR) exon 9 provide a recurrent driver mutation of essential thrombocythemia (ET) and primary myelofibrosis among myeloproliferative neoplasms (MPNs). Here, we generated knock-in mice with murine Calr exon 9 mimicking the human CALR mutations, using the CRISPR-Cas9 method. Knock-in mice with del10 [Calrdel10/WT (wild−type) mice] exhibited an ET phenotype with increases of peripheral blood (PB) platelets and leukocytes, and accumulation of megakaryocytes in bone marrow (BM), while those with ins2 (Calrins2/WT mice) showed a slight splenic enlargement. Phosphorylated STAT3 (pSTAT3) was upregulated in BM cells of both knock-in mice. In BM transplantation (BMT) recipients from Calrdel10/WT mice, although PB cell counts were not different from those in BMT recipients from CalrWT/WT mice, Calrdel10/WT BM-derived macrophages exhibited elevations of pSTAT3 and Endothelin-1 levels. Strikingly, BMT recipients from Calrdel10/WT mice developed more severe pulmonary hypertension (PH)—which often arises as a comorbidity in patients with MPNs—than BMT recipients from CalrWT/WT mice, with pulmonary arterial remodeling accompanied by an accumulation of donor-derived macrophages in response to chronic hypoxia. In conclusion, our murine model with the frameshifted murine Calr presented an ET phenotype analogous to human MPNs in molecular mechanisms and cardiovascular complications such as PH. SN - 1756-8722 UR - https://doi.org/10.1186/s13045-021-01064-8 DO - 10.1186/s13045-021-01064-8 ID - Minakawa2021 ER -