Defective Notch signaling in microenvironment causes myeloproliferative disease Young-Yun Kong, PhD Laboratory of Mouse Genetics Department of Biological Sciences Seoul National University

Hematopoietic niche in bone marrow

Maintenance Migration Proliferation Differentation B IL-7 NK DC CXCL12 SNO Opn HSC SDF1 CXCR4 Maintenance Migration Proliferation Differentation Jag1 Notch N-cad N-cad SCF c-Kit Ang1 Tie2 MMP9 B HSC CLP IL-7 NK CXCL12 DC HSC GMP M CMP G E MEP HSC Meg Osteoblastic Stromal Vascular

Notch signaling in HSC maintenance Osteoblastic cells regulate the hematopoietic stem cell niche. Nature 425:841-6, 2003 ▶ Osteoblast Jag1  Notch signaling  HSC expansion Jagged1-dependent Notch signaling is dispensable for hematopoietic stem cell self-renewal and differentiation. Blood. 105:2340-2342, 2005 ▶ Mx1-cre;Jag1 cKO mice  Normal hematopoiesis Integration of Notch and Wnt signaling in hematopoietic stem cell maintenance. Nat Immunol 6:314-22, 2005 ▶ Notch ↓  HSC differentiation↑ in vitro  Depletion in vivo

Notch interactions in hematopoiesis Bone marrow Microenvironment Hematopoietic cells J2 Mib1 Mib1 N1/2 HSC N1/2 J1/2,D1 Mib1 Progeny Mib1

Notch signaling pathway E3 ligase Ligand Receptor Target Notch signaling PS1/2 Mib1 Jag1 Notch1 Mib2 Jag2 Hes Hey Mammalian Notch2 *RBPjk Neur1 Dll1 Neur2 Dll3 Notch3 *RBPjk-dep/indep Dll4 Notch4 Signal-sending cell Signal-receiving cell Dll1 Dll3(?) Dll4 Jag1 Jag2 Koo et al. Development, 132:3459, 2005 Koo et al. JBC. 280:22335, 2005 Song et al. JBC. 281:36391, 2006 Koo et al. PLoS ONE, 2:e1221, 2007 Mib1

What Notch interaction is required for hematopoiesis? Bone marrow Microenvironment Hematopoietic cells J2 Mib1 Mib1 N1/2 HSC N1/2 J1/2,D1 Mib1 Progeny Mib1

Disruption of Mib1 in Mib1 cKO mice A Mib1f/f 1 2 3 4 MMTV-cre Mx1-cre Cre Mib1-/- 1 4 B C

Myeloproliferative disease in Mib1 cKO mice

Leukocyte infiltration in multi-organs Blood Spleen Liver Liver Kidney

Disease Progression of Group I & II B WT Group I Group II WT Group I Group II

Increased GMP in Group I & II mice

Spleen PBL

Myeloproliferative disease (MPD) ◎ MMTV-Cre;Mib1 cKO mice ▶ Hepatosplenomegaly ▶ Anemia ▶ Granulocytosis accompanied with eosinophilia and bosophilia ▶ Leukocyte infiltration in multiple organs Dr. Sun-Hee Kim, Samsung Medical Center MPD-like myeloid leukemia, chronic type; CML-like disease Bethesda proposals for classification of nonlymphoid hematopoietic neoplasms in mice. Kogan et al. Blood, 100:238-45, 2002

Which Notch interaction is responsible for MPD? Bone marrow Microenvironment Hematopoietic cells J2 Mib1 X X Mib1 N1/2 HSC N1/2 ? ? ? X J1/2,D1 Mib1 Progeny X Mib1

Mib1-null BM microenvironment is leukemogenic Bone marrow Microenvironment Hematopoietic cells J2 Mib1 X Mib1 N1/2 HSC N1/2 ? J1/2,D1 Mib1 Progeny X Mib1 MPD

A B BMSC D/J Notch1 CBF luc C2C12

Defective Notch activation in LSK? BM stromal cell 2 3 4 1 mib1-/- cre mib1f/f X Mib1 Jag1/2 Dll1 N1/2 B PS1/2 LSK *RBPjk GFP TNR mice Notch reporter (CBF1-GFP)

Does BM Microenvironment require Notch signaling? Bone marrow Microenvironment Hematopoietic cells J2 Mib1 X Mib1 N1/2 HSC N1/2 X ? J1/2,D1 Mib1 Progeny X Mib1

BM Microenvironment requires Notch signaling CD45.1 BMC BM stromal cell Survival Mib1-/- A 1 4 Cre Mib1f/f 1 2 3 4 X Mib1 Jag1/2 Dll1 N1/2 B PS1/2 ROSA Stop N1ICD N1ICD Cre *RBPjk ROSA N1ICD

Wild-type BM microenvironment Mib1 null BM microenvironment Summary D1,J1/2 Dtx1/2 RBP-j Mib1 N1/2 PS1/2 Wild-type BM microenvironment Normal hematopoiesis HSC Granulocytosis MPD HSC Mib1 null BM microenvironment D1,J1/2 X X N1/2 Mib1 Kim et al. Blood. 2008 Sep 25. [Epub ahead of print]

? ? Bone marrow Microenvironment Hematopoietic cells J2 N1/2 HSC N1/2 Mib1 Mib1 N1/2 HSC N1/2 ? essential ? J1/2,D1 Mib1 Progeny Mib1 Walkley CR et al. Rb Regulates Interactions between Hematopoietic Stem Cells and Their Bone Marrow Microenvironment. Cell. 2007;129:1081. Walkley CR et al. A Microenvironment-Induced Myeloproliferative Syndrome Caused by RAR gamma Deficiency. Cell. 2007;129:1097

POSTECH Young-Woong Kim Bon-Kyoung Koo, PhD Hyun-Woo Jeong Mi-Jeong Yoon, PhD Ran Song, PhD Juhee Shin Samsung Medical Center Dr. Sun-Hee Kim Catholic University Dr. Dae-Chul Jeong