OBJECTIVE: The evolutionarily conserved Kit receptor is vital for function of hematopoietic stem cells (HSC). Kit(W-41) (W-41) and Kit(W-42) (W-42) are single residue changes in the KIT intracellular phosphotransferase domain, while Kit(W-v) (W-v) is a single residue change in the ATP binding domain. This study tests how each mutation affects HSC function. METHODS: Cells in mutant and C57BL/6J(+/+) blood and marrow were compared. Overall HSC function was measured by competitive repopulation. Functions of specific progenitor populations were tested with stage-specific competitive repopulation and standard colony-forming unit assays. RESULTS: Bone marrow cells from these Kit mutants are severely defective at reconstituting peripheral blood lineages and bone marrow of irradiated recipients, when compared to +/+ control marrow. These defects increased with time. Marrow from W-41/+ and W-v/+ functions similarly but better than marrow from W-41/W-41 and W-42/+, to repopulate the erythroid and lymphoid lineages. Long-term (LT) and short-term (ST) HSC from W-v/+, W-41/W-41, and W-42/+ are more defective at reconstituting bone marrow than LT- and ST-HSC from W-41/+ and +/+. Common myeloid progenitor (CMP) cells from W-42/+ and W-41/W-41 are more defective at producing spleen colonies than CMP from W-v/+ and W-41/+. CONCLUSION: Heterozygous Kit mutants with little or no apparent anemia exhibit surprisingly large defects in overall HSC function. Multiplying the fractional defects in LT-HSC, ST-HSC, and CMP can account for overall effects of W-v/+, but does not completely account for the defects observed with W-41/+, W-42/+, and W-41/W-41.
OBJECTIVE: The evolutionarily conserved Kit receptor is vital for function of hematopoietic stem cells (HSC). Kit(W-41) (W-41) and Kit(W-42) (W-42) are single residue changes in the KIT intracellular phosphotransferase domain, while Kit(W-v) (W-v) is a single residue change in the ATP binding domain. This study tests how each mutation affects HSC function. METHODS: Cells in mutant and C57BL/6J(+/+) blood and marrow were compared. Overall HSC function was measured by competitive repopulation. Functions of specific progenitor populations were tested with stage-specific competitive repopulation and standard colony-forming unit assays. RESULTS: Bone marrow cells from these Kit mutants are severely defective at reconstituting peripheral blood lineages and bone marrow of irradiated recipients, when compared to +/+ control marrow. These defects increased with time. Marrow from W-41/+ and W-v/+ functions similarly but better than marrow from W-41/W-41 and W-42/+, to repopulate the erythroid and lymphoid lineages. Long-term (LT) and short-term (ST) HSC from W-v/+, W-41/W-41, and W-42/+ are more defective at reconstituting bone marrow than LT- and ST-HSC from W-41/+ and +/+. Common myeloid progenitor (CMP) cells from W-42/+ and W-41/W-41 are more defective at producing spleen colonies than CMP from W-v/+ and W-41/+. CONCLUSION: Heterozygous Kit mutants with little or no apparent anemia exhibit surprisingly large defects in overall HSC function. Multiplying the fractional defects in LT-HSC, ST-HSC, and CMP can account for overall effects of W-v/+, but does not completely account for the defects observed with W-41/+, W-42/+, and W-41/W-41.
Authors: Michihiro Kobayashi; Sarah C Nabinger; Yunpeng Bai; Momoko Yoshimoto; Rui Gao; Sisi Chen; Chonghua Yao; Yuanshu Dong; Lujuan Zhang; Sonia Rodriguez; Yumi Yashiro-Ohtani; Warren S Pear; Nadia Carlesso; Mervin C Yoder; Reuben Kapur; Mark H Kaplan; Hugo Daniel Lacorazza; Zhong-Yin Zhang; Yan Liu Journal: Stem Cells Date: 2017-01-19 Impact factor: 6.277
Authors: Shayu Deshpande; Benedikt Bosbach; Yasemin Yozgat; Christopher Y Park; Malcolm A S Moore; Peter Besmer Journal: Stem Cells Date: 2013-08 Impact factor: 6.277
Authors: Sung O Park; Heather L Wamsley; Kyungmi Bae; Zhongbo Hu; Xiaomiao Li; Se-woon Choe; William B Slayton; S Paul Oh; Kay-Uwe Wagner; Peter P Sayeski Journal: PLoS One Date: 2013-03-27 Impact factor: 3.240
Authors: Joakim S Dahlin; Fiona K Hamey; Blanca Pijuan-Sala; Mairi Shepherd; Winnie W Y Lau; Sonia Nestorowa; Caleb Weinreb; Samuel Wolock; Rebecca Hannah; Evangelia Diamanti; David G Kent; Berthold Göttgens; Nicola K Wilson Journal: Blood Date: 2018-03-27 Impact factor: 22.113