PUBLICATION

Hif-1α and Hif-2α regulate hemogenic endothelium and hematopoietic stem cell formation in zebrafish

Authors

Gerri, C., Marass, M., Rossi, A., Stainier, D.Y.R.

ID

ZDB-PUB-180118-12

Date

2018

Source

Blood 131(9): 963-973 (Journal)

Registered Authors

Stainier, Didier

Keywords

none

MeSH Terms

Animals
Endothelium, Vascular/cytology
Endothelium, Vascular/metabolism*
Gene Expression Regulation/genetics
Gene Knockdown Techniques
Hematopoietic Stem Cells/cytology
Hematopoietic Stem Cells/metabolism*
Hypoxia-Inducible Factor 1, alpha Subunit/genetics
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
Receptors, Notch/genetics
Receptors, Notch/metabolism*
Signal Transduction*
Zebrafish/genetics
Zebrafish/metabolism*

(all 14)

PubMed

29339404 Full text @ Blood

Abstract

During development, hematopoietic stem cells (HSCs) derive from specialized endothelial cells (ECs) called hemogenic endothelium (HE) via a process called endothelial-to-hematopoietic transition (EHT). Hypoxia-inducible factor-1α (HIF-1α) has been reported to positively modulate EHT in vivo, but current data indicate the existence of other regulators of this process. Here we show that in zebrafish, Hif-2α also positively modulates HSC formation. Specifically, HSC marker gene expression is strongly decreased in hif-1aa;hif-1ab (hif-1α) and in hif-2aa;hif-2ab (hif-2α) zebrafish mutants and morphants. Moreover, live imaging studies reveal a positive role for hif-1α and hif-2α in regulating HE specification. Knockdown of hif-2α in hif-1α mutants leads to a greater decrease in HSC formation, indicating that hif-1α and hif-2α have partially overlapping roles in EHT. Furthermore, hypoxic conditions, which strongly stimulate HSC formation in wild-type animals, have little effect in the combined absence of Hif-1α and Hif-2α function. In addition, we present evidence for Hif and Notch working in the same pathway upstream of EHT. Both notch1a and notch1b mutants display impaired EHT, which cannot be rescued by hypoxia. However, overexpression of the Notch intracellular domain in ECs is sufficient to rescue the hif-1α and hif-2α morphant EHT phenotype, suggesting that Notch signaling functions downstream of the Hif pathway during HSC formation. Altogether, our data provide genetic evidence that both Hif-1α and Hif-2α regulate EHT upstream of Notch signaling.

Genes / Markers

Marker	Marker Type	Name
efnb2a	GENE	ephrin-B2a
epas1a	GENE	endothelial PAS domain protein 1a
epas1b	GENE	endothelial PAS domain protein 1b
gata1a	GENE	GATA binding protein 1a
gata2b	GENE	GATA binding protein 2b
hif1aa	GENE	hypoxia inducible factor 1 subunit alpha a
hif1ab	GENE	hypoxia inducible factor 1 subunit alpha b
myb	GENE	v-myb avian myeloblastosis viral oncogene homolog
notch1a	GENE	notch receptor 1a
notch1b	GENE	notch receptor 1b

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Figures

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Expression

Phenotype

Fish	Conditions	Stage	Phenotype	Figure
WT	hypoxia	Prim-25	hematopoietic progenitor cell differentiation increased occurrence, abnormal	Fig. 3
WT	hypoxia	Prim-25	hematopoietic system myb expression increased amount, abnormal	Fig. 5
WT	hypoxia	Prim-25	hematopoietic system myb expression increased amount, abnormal	Fig. 3
WT	hypoxia	Prim-25	hematopoietic system runx1 expression increased amount, abnormal	Fig. 5
WT	hypoxia	Prim-25	hematopoietic system runx1 expression increased amount, abnormal	Fig. 3
WT	hypoxia	Prim-25	hemopoiesis increased occurrence, abnormal	Fig. 3
WT	hypoxia	Prim-25	ventral wall of dorsal aorta myb expression increased amount, abnormal	Fig. 5
WT	hypoxia	Prim-25	ventral wall of dorsal aorta myb expression increased amount, abnormal	Fig. 3
WT	hypoxia	Prim-25	ventral wall of dorsal aorta runx1 expression increased amount, abnormal	Fig. 5
WT	hypoxia	Prim-25	ventral wall of dorsal aorta runx1 expression increased amount, abnormal	Fig. 3

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Mutations / Transgenics

Allele	Construct	Type	Affected Genomic Region
bns89		Indel	hif1aa
bns90		Small Deletion	hif1ab
bns135		Small Deletion	notch1a
bns231		Small Deletion	epas1a
bns232		Indel	epas1b
kca3Tg	Tg(5xUAS-E1B:6xMYC-notch1a)	Transgenic Insertion
kca4Tg	Tg(-1.5hsp70l:GAL4)	Transgenic Insertion
s843Tg	Tg(kdrl:EGFP)	Transgenic Insertion
s896Tg	Tg(kdrl:Hsa.HRAS-mCherry)	Transgenic Insertion
sa11236		Point Mutation	notch1b

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Human Disease / Model

Sequence Targeting Reagents

Fish

Antibodies

Orthology

Engineered Foreign Genes

Marker	Marker Type	Name
EGFP	EFG	EGFP
GAL4	EFG	GAL4
GAL4FF	EFG	GAL4FF
mCherry	EFG	mCherry

Mapping

Gerri et al., 2018 ZDB-PUB-180118-12 PMID:29339404

Hif-1α and Hif-2α regulate hemogenic endothelium and hematopoietic stem cell formation in zebrafish

Gerri et al., 2018

ZDB-PUB-180118-12
PMID:29339404