In vivo models to study cohesin function in hematopoiesis and leukemia
| Model system . | Reference . | Hematopoietic phenotype . | Chromatin changes . | Transcriptional changes . |
|---|---|---|---|---|
| Mx1-Cre+; Smc3fl/fl Mx1-Cre+; Smc3fl/+ | 100 | BM aplasia, lethal -↑LSK, ↓MP, ↑ST-HSC, ↓LT-HSC, ↑MPP -Competitive advantage in transplant assays -AML in cooperation with FLT3-ITD | — ↓Chromatin accessibility at enhancers of downregulated genes | — -Global reduction in transcription -↓Expression of TFs associated with lineage commitment |
| Vav1-Cre+; Smc3fl/fl ERT2-Cre+; Smc3fl/fl ERT2-Cre+; Smc3fl/+ Vav1-Cre+; Smc3fl/+ | 101 | Embryonic lethal BM aplasia, lethal -No change in number of HSPCs -Competitive disadvantage in transplant assays, partial rescue in cooperation with DNMT3A+/− No change in number of HSPCs | — — — Minimal changes in chromatin accessibility | — — — Minimal global transcriptional changes |
| Mx1-Cre+; Stag2fl/fl Mx1-Cre+; Stag1fl/fl Mx1-Cre+; Stag1fl/fl Stag2fl/fl | 102 | -↑LSK, ↑MPP, ↑ST-HSC, ↑LT-HSC, ↑GMP -Competitive advantage in transplant assays -PB with progressive leukopenia, thrombocytopenia, ↑myeloid, ↓B cells -Myelodysplasia in the BM -No change in number of HSPCs -No competitive advantage in transplant assays -No morphologic changes BM failure, lethal | -↓ Chromatin accessibility at enhancers of downregulated genes -↓Chromatin insulation — — | -↓Cell commitment (B cell > myeloid, erythroid) -↑Self-renewal signature — — |
| Transplant models of Rad21, Smc1a, and Stag2 TRE-shRNA; ROSA26(M2rtTA/+) | 103 | -↓ST- and LT-HSC, ↑GMP, ↓MEP, ↑MPP -Extramedullary hematopoiesis and MPN in aged Smc1ashRNA mice, exaggerated in compound Stag2shRNA Smc1ashRNA | ↑Chromatin accessibility of myeloid lineage genes | -↑Myeloid differentiation -↓Lymphoid-specific gene expression |
| Transplant models of human cord blood CD34+ cells expressing RAD21 shRNA in NSG Culture of RAD21 E212*, RAD21 Q592* and SMC1A R711G-expressing human CD34+ cord blood cells | 9 | -↑CD34+ cell frequency and engraftment in BM of NSG mice -Myeloid differentiation skewing -↓Erythroid and myeloid differentiation -↑Serial replating | — -Global↓ in chromatin accessibility at transcriptional regulators -↑Chromatin accessibility for ERG, GATA2, and RUNX1 consensus binding sites | — -↑HSC gene expression (HOX genes, MEIS1) -↓Myeloid differentiation genes (MPO, CSF1R) |
| Transplant models of human cord blood CD34+CD38−CD90+ CD45RA− cells expressing STAG2 or SMC3 shRNA in NSG | 105 | -↑Engraftment in the BM in primary and secondary transplants -Myeloid skewing (with STAG2 shRNA, not SMC3 shRNA) -↑Frequency of CD34+CD38-cells; | ↑HSC gene expression | |
| Transplant model of LSK transduced with Rad21 shRNA | 104 | -↓HSPC differentiation in animals on dietary restriction > ad libitum diet -↑HSC self-renewal with serial transplantation with AL diet, aging and inflammation -↓LPS-induced myeloid differentiation of LSK cells | ↓Chromatin accessibility, accentuated with LPS treatment | ↓NF-κB dependent signaling in transplanted HSCs |
| Mx1-Cre+; Stag2fl/− Mx1-Cre+; Stag2fl/− Runx1fl/fl | 36 | -Mild ↓WBC, ↓B cells, ↑RDW -Mild trilineage dysplasia -↑LSK,ST- and LT-HSC, MPP -Myeloid skewing, ↑CMP, ↑GMP, ↓CLP, ↓MEP, ↓erythroid program -Pancytopenia, ↑RDW, ↑MCV -↑LSK, ↑MPP, ↓ST-and LT-HSC -Myeloid skewing -MDS, severe trilineage dysplasia | -↑Chromatin accessibility at RUNX1, GATA2 sites -↓Chromatin accessibility at IRF sites -Slight ↑TAD boundary insulation -↑Chromatin accessibility changes compared with Mx1-Cre+; Stag2fl/− -Slight ↑TAD boundary insulation -↓E-P loop formation | -↑Myeloid program -↓Lymphoid program -↑Gene expression changes compared with Mx1-Cre+; Stag2fl/− -↓HoxA9, ↑Gata2, ↑Fos -↓Expression of high pausing genes |
| Sequential transplant model of Cas9+ c-kit+ cells expressing Tet2 and Stag2 sgRNA Culture of isogenic STAG2 knockout U937 cells | 76 | -Leukocytosis, anemia, thrombocytopenia, lymphopenia -MDS with evidence of dysplasia, ↓megakaryocytes, ↑erythrophagocytosis>-↑LSK,ST- and LT-HSC, MPP — | — -↑Intermixing of A and B compartments -↓TAD boundary insulation -↑Size extruded loops | — -↑Myeloid program -↓DNA damage repair -↑Type 1 interferon response |
| Model system . | Reference . | Hematopoietic phenotype . | Chromatin changes . | Transcriptional changes . |
|---|---|---|---|---|
| Mx1-Cre+; Smc3fl/fl Mx1-Cre+; Smc3fl/+ | 100 | BM aplasia, lethal -↑LSK, ↓MP, ↑ST-HSC, ↓LT-HSC, ↑MPP -Competitive advantage in transplant assays -AML in cooperation with FLT3-ITD | — ↓Chromatin accessibility at enhancers of downregulated genes | — -Global reduction in transcription -↓Expression of TFs associated with lineage commitment |
| Vav1-Cre+; Smc3fl/fl ERT2-Cre+; Smc3fl/fl ERT2-Cre+; Smc3fl/+ Vav1-Cre+; Smc3fl/+ | 101 | Embryonic lethal BM aplasia, lethal -No change in number of HSPCs -Competitive disadvantage in transplant assays, partial rescue in cooperation with DNMT3A+/− No change in number of HSPCs | — — — Minimal changes in chromatin accessibility | — — — Minimal global transcriptional changes |
| Mx1-Cre+; Stag2fl/fl Mx1-Cre+; Stag1fl/fl Mx1-Cre+; Stag1fl/fl Stag2fl/fl | 102 | -↑LSK, ↑MPP, ↑ST-HSC, ↑LT-HSC, ↑GMP -Competitive advantage in transplant assays -PB with progressive leukopenia, thrombocytopenia, ↑myeloid, ↓B cells -Myelodysplasia in the BM -No change in number of HSPCs -No competitive advantage in transplant assays -No morphologic changes BM failure, lethal | -↓ Chromatin accessibility at enhancers of downregulated genes -↓Chromatin insulation — — | -↓Cell commitment (B cell > myeloid, erythroid) -↑Self-renewal signature — — |
| Transplant models of Rad21, Smc1a, and Stag2 TRE-shRNA; ROSA26(M2rtTA/+) | 103 | -↓ST- and LT-HSC, ↑GMP, ↓MEP, ↑MPP -Extramedullary hematopoiesis and MPN in aged Smc1ashRNA mice, exaggerated in compound Stag2shRNA Smc1ashRNA | ↑Chromatin accessibility of myeloid lineage genes | -↑Myeloid differentiation -↓Lymphoid-specific gene expression |
| Transplant models of human cord blood CD34+ cells expressing RAD21 shRNA in NSG Culture of RAD21 E212*, RAD21 Q592* and SMC1A R711G-expressing human CD34+ cord blood cells | 9 | -↑CD34+ cell frequency and engraftment in BM of NSG mice -Myeloid differentiation skewing -↓Erythroid and myeloid differentiation -↑Serial replating | — -Global↓ in chromatin accessibility at transcriptional regulators -↑Chromatin accessibility for ERG, GATA2, and RUNX1 consensus binding sites | — -↑HSC gene expression (HOX genes, MEIS1) -↓Myeloid differentiation genes (MPO, CSF1R) |
| Transplant models of human cord blood CD34+CD38−CD90+ CD45RA− cells expressing STAG2 or SMC3 shRNA in NSG | 105 | -↑Engraftment in the BM in primary and secondary transplants -Myeloid skewing (with STAG2 shRNA, not SMC3 shRNA) -↑Frequency of CD34+CD38-cells; | ↑HSC gene expression | |
| Transplant model of LSK transduced with Rad21 shRNA | 104 | -↓HSPC differentiation in animals on dietary restriction > ad libitum diet -↑HSC self-renewal with serial transplantation with AL diet, aging and inflammation -↓LPS-induced myeloid differentiation of LSK cells | ↓Chromatin accessibility, accentuated with LPS treatment | ↓NF-κB dependent signaling in transplanted HSCs |
| Mx1-Cre+; Stag2fl/− Mx1-Cre+; Stag2fl/− Runx1fl/fl | 36 | -Mild ↓WBC, ↓B cells, ↑RDW -Mild trilineage dysplasia -↑LSK,ST- and LT-HSC, MPP -Myeloid skewing, ↑CMP, ↑GMP, ↓CLP, ↓MEP, ↓erythroid program -Pancytopenia, ↑RDW, ↑MCV -↑LSK, ↑MPP, ↓ST-and LT-HSC -Myeloid skewing -MDS, severe trilineage dysplasia | -↑Chromatin accessibility at RUNX1, GATA2 sites -↓Chromatin accessibility at IRF sites -Slight ↑TAD boundary insulation -↑Chromatin accessibility changes compared with Mx1-Cre+; Stag2fl/− -Slight ↑TAD boundary insulation -↓E-P loop formation | -↑Myeloid program -↓Lymphoid program -↑Gene expression changes compared with Mx1-Cre+; Stag2fl/− -↓HoxA9, ↑Gata2, ↑Fos -↓Expression of high pausing genes |
| Sequential transplant model of Cas9+ c-kit+ cells expressing Tet2 and Stag2 sgRNA Culture of isogenic STAG2 knockout U937 cells | 76 | -Leukocytosis, anemia, thrombocytopenia, lymphopenia -MDS with evidence of dysplasia, ↓megakaryocytes, ↑erythrophagocytosis>-↑LSK,ST- and LT-HSC, MPP — | — -↑Intermixing of A and B compartments -↓TAD boundary insulation -↑Size extruded loops | — -↑Myeloid program -↓DNA damage repair -↑Type 1 interferon response |
GMP, Lin− cKit+ Sca1− Cd34+ Fcg+; LSK, Lin− Sca-1+ c-Kit+; LT-HSC, LSK+ Cd150+ Cd48−); MP myeloid progenitors (Lin− Sca-1− c-Kit+); MPP, LSK+ Cd150− Cd48+ Cd127−; NSG NOD/SCID/IL2R-gamma null mice; PB peripheral blood; ST-HSC, LSK+ Cd150− Cd48−; RDW red cell distribution width; WBC, white blood cell.