PUBLICATION

TLR7 ligation augments hematopoiesis in Rps14 (uS11) deficiency via paradoxical suppression of inflammatory signalling

Authors

Peña, O.A., Lubin, A., Hockings, C., Rowell, J., Jung, Y., Hoade, Y., Dace, P.E.I., Valdivia, L.E., Tuschl, K., Boiers, C., Virgilio, M., Richardson, S.E., Payne, E.M.

ID

ZDB-PUB-210826-4

Date

2021

Source

Blood advances 5(20): 4112-4124 (Journal)

Registered Authors

Payne, Elspeth M. (Beth), Tuschl, Karin, Valdivia, Leonardo

Keywords

none

MeSH Terms

Toll-Like Receptor 7/genetics
Humans
Signal Transduction
Myelodysplastic Syndromes*/genetics
Animals
Zebrafish*
Hematopoiesis

(all 7)

PubMed

34432872 Full text @ Blood Adv

Abstract

Myelodysplastic syndrome (MDS) is a haematological malignancy characterised by blood cytopenias and predisposition to acute myeloid leukaemia (AML). Therapies for MDS are lacking, particularly those that impact the early stages of disease. We developed a model of MDS using zebrafish using knockout of Rps14, the primary mediator of the anaemia associated with del (5q) MDS. These mutant animals display dose- and age-dependent abnormalities in haematopoiesis, culminating in bone marrow failure with dysplastic features. We utilized rps14 knockdown to undertake an in vivo small molecule screen to identify compounds that ameliorate the MDS phenotype, identifying imiquimod, an agonist of TLR7 and TLR8. Imiquimod alleviates anaemia by promoting haematopoietic stem and progenitor cell expansion and erythroid differentiation, the mechanism of which is dependent on TLR7 ligation and Myd88. TLR7 activation in this setting paradoxically promoted an anti-inflammatory gene signature indicating crosstalk between pro-inflammatory pathways endogenous to Rps14 loss and NFkappaB pathway via TLR7. Finally, we show that in highly purified human bone marrow samples from anaemic patients, imiquimod leads to an increase in erythroid output from myelo-erythroid progenitors and common myeloid progenitors. Our findings have both specific implications for the development of targeted therapeutics for del (5q) MDS and wider significance identifying a potential role for TLR7 ligation in modifying anaemia.

Genes / Markers

Figures

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Expression

Gene	Fish	Conditions	Stage	Anatomy	Assay	Figure
ela3l	rps14^zf3737/+	standard conditions	Day 4	whole organism	RNA-Seq	Figure 5.
il1b	AB	chemical treatment by environment: phenylhydrazine	Day 4	whole organism	ISH	Figure 5.
il1b	rps14^zf3737/+	standard conditions	Day 4	whole organism	ISH	Figure 5.
il1b	rps14^zf3737/+	chemical treatment by environment: phenylhydrazine	Day 4	whole organism	ISH	Figure 5.
il1b	rps14^zf3737/+	chemical treatment by environment: imiquimod, chemical treatment by environment: phenylhydrazine	Day 4	whole organism	ISH	Figure 5.
il1b	rps14^zf3737/+	chemical treatment by environment: imiquimod	Day 4	whole organism	ISH	Figure 5.
myb	rps14^zf3737/+	standard conditions	Day 4	caudal hematopoietic tissue hematopoietic multipotent progenitor cell	ISH	Figure 1.
prkab2	rps14^zf3737/+	standard conditions	Day 4	whole organism	RNA-Seq	Figure 5.
rnf14	rps14^zf3737/+	standard conditions	Day 4	whole organism	RNA-Seq	Figure 5.
rps14	rps14^zf3737/+	standard conditions	Day 4	whole organism	RNA-Seq	Figure 5.

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Phenotype

Fish	Conditions	Stage	Phenotype	Figure
AB	chemical treatment by environment: phenylhydrazine	Day 4	whole organism il1b expression decreased amount, abnormal	Figure 5.
AB	chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte cellular response to chemical stress normal process quality, normal	Figure 4.
AB	chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte cellular response to chemical stress normal process quality, normal	Figure 2.
AB	chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte normal amount, normal	Figure 4.
AB	chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte normal amount, normal	Figure 2.
AB	chemical treatment by environment: imiquimod, chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte cellular response to chemical stress normal process quality, normal	Figure 4.
AB	chemical treatment by environment: imiquimod, chemical treatment by environment: phenylhydrazine	Day 6	nucleate erythrocyte normal amount, normal	Figure 4.
AB + MO1-rps14	standard conditions	Day 4	nucleate erythrocyte decreased amount, abnormal	Figure 3.
AB + MO1-rps14	chemical treatment by environment: imiquimod	Day 4	nucleate erythrocyte decreased amount, ameliorated	Figure 3.
AB + MO1-rps14	chemical treatment by environment: leucine	Day 4	nucleate erythrocyte decreased amount, ameliorated	Figure 3.

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Mutations / Transgenics

Allele	Construct	Type	Affected Genomic Region
la2Tg	Tg(-6.0itga2b:EGFP)	Transgenic Insertion
sd2Tg	Tg(gata1a:DsRed)	Transgenic Insertion
sh235Tg	Tg(6xHsa.NFKB:EGFP)	Transgenic Insertion
zf3737		Indel	rps14

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Human Disease / Model

Human Disease	Fish	Conditions	Evidence
anemia	rps14^zf3737/+	standard conditions	TAS
myelodysplastic syndrome	rps14^zf3737/+	standard conditions	TAS

Sequence Targeting Reagents

Target	Reagent	Reagent Type
gata1a	MO1-gata1a	MRPHLNO
myd88	MO2-myd88	MRPHLNO
rps14	MO1-rps14	MRPHLNO
tlr7	CRISPR2-tlr7	CRISPR

Fish

Fish
AB
AB + MO1-rps14
la2Tg/la2Tg
rps14^zf3737/+
rps14^zf3737/+ + CRISPR2-tlr7
rps14^zf3737/+; la2Tg/la2Tg
rps14^zf3737/+; sd2Tg/sd2Tg
rps14^zf3737/+; sh235Tg/sh235Tg
rps14^{zf3737/zf3737}
rps14^{zf3737/zf3737}; la2Tg/la2Tg

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Antibodies

Name	Type	Antigen Genes	Isotypes	Host Organism
Ab1-rps14	polyclonal			Rabbit
Ab3-eif2a	monoclonal		IgG	Rabbit

Orthology

Engineered Foreign Genes

Marker	Marker Type	Name
DsRed	EFG	DsRed
EGFP	EFG	EGFP

Mapping

Peña et al., 2021 ZDB-PUB-210826-4 PMID:34432872

TLR7 ligation augments hematopoiesis in Rps14 (uS11) deficiency via paradoxical suppression of inflammatory signalling

Peña et al., 2021

ZDB-PUB-210826-4
PMID:34432872