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

2. Hematopoietic niche in bone marrow

3. 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

4. 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: , 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

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

6. 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

7. 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

8. Disruption of Mib1 in Mib1 cKO miceA
Mib1f/f 1 2 3 4
MMTV-cre
Mx1-cre
Cre
Mib1-/- 1 4 B C

9. Myeloproliferative disease in Mib1 cKO mice

10. Leukocyte infiltration in multi-organs
Blood
Spleen
Liver
Liver
Kidney

11. Disease Progression of Group I & IIB WT
Group I
Group II WT
Group I
Group II

12. Increased GMP in Group I & II mice

13. Spleen
PBL

14. 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

15. 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

17. 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

18. A B
BMSC
D/J
Notch1
CBF luc
C2C12

19. 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)

20. 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

21. 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

22. 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 Sep 25. [Epub ahead of print]

23. ? ? 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

24. 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