PB1061 - Impact of FII, FVIII, or FIX deficiency on bone mineralization in a zebrafish model

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Brigitte Tardy, MD PhD

PH
Université Jean Monnet Saint-Étienne, CHU Saint-Étienne, Centre de traitement de l'hémophilie, Mines Saint-Etienne, INSERM, SAINBIOSE U1059, F-42023 SAINT-ÉTIENNE, FRANCE
St Etienne, Rhone-Alpes, France

Co-Author(s)

ND

Nam Do khoa

Ingénieur
Azelead, 377 rue du Pr Blayac, Montpellier, France
Montpellier, Languedoc-Roussillon, France
AM

Aurélie Montmartin

IGE
Université Jean Monnet Saint-Étienne, Mines Saint-Etienne, INSERM, SAINBIOSE U1059, F-42023, SAINT-ÉTIENNE, FRANCE
Saint-Etienne, Rhone-Alpes, France
KK

Karima Kissa

B.Sc., Ph.D
Azelead, 377 rue du Pr Blayac, Montpellier, France
Montpellier, Languedoc-Roussillon, France
PD

Pauline Damien

PhD
Université Jean Monnet Saint-Étienne, CHU Saint-Étienne, CIC1408 , Mines Saint-Etienne, INSERM, SAINBIOSE U1059, F-42023 SAINT-ÉTIENNE, FRANCE
Saint-Etienne, Languedoc-Roussillon, France
BT

Bernard Tardy

PU, PH
Université Jean Monnet Saint-Étienne, CHU Saint-Étienne, CIC1408 , Mines Saint-Etienne, INSERM, SAINBIOSE U1059, F-42023 SAINT-ÉTIENNE, FRANCE
Saint-Etienne, Rhone-Alpes, France
LF

Laura Fontenille

B.Sc., Ph.D
Azelead, 377 rue du Pr Blayac, Montpellier, France
Montpelleir, Languedoc-Roussillon, France

Background: The physiopathological mechanism underlying hemophilia-related osteopenia is considered multifactorial and could be partly caused by FVIII or FIX deficiency. FVIII and FIX deficiencies could affect bone metabolism directly and/or indirectly through impaired thrombin generation.

Aims: In this study, we aimed to evaluate the effect of FII, FVIII, or FIX deficiency on bone metabolism in a Zebrafish model.

Methods: We used the ability of morpholinos (MO), antisense oligonucleotides to target RNA and reversibly inactivate fII, fVIII, or fIX genes expression. The cartilage and bone were stained and observed in zebrafish embryos at 6, 10 and 20 days post-fertilization (dpf).

Results: FII, fVIII, and fIX gene inactivation resulted in partial embryonic lethality, with some of the surviving embryos developing features of facial dysmorphology, (either flatter or more pointed compared to control embryos).
At 6 dpf, we identified the ceratohyal, branchiostegal, cleithrum, ceratobranchial, and hyomandibular cartilage structures of morphant embryos, showing no differences with control embryos.
At 10 dpf, the ceratohyal cartilage failed to ossify and no mineralized craniofacial bone structure was observed in zebrafish embryos, when fII, fVIII, and fIX genes were inactivated (compared to zebrafish controls). The lack of mineralization was most predominant in fVIII morphants embryos.
At 20 dpf, after loss of MO function, this phenomen was reversed and the ceratohyal cartilage differentiated into bone in 100% of morphants and control embryos.

Conclusion(s): The reversible reduced bone density observed in fII, fVIII and fIX morphants zebrafish embryos is related to FVIII or FIX defects and/or to thrombin generation deficiency. This finding suggest that the correction of FVIII or FIX and/or thrombin generation deficiency in haemophilia patient could prevent impaired bone metabolism.