Aude-Anaïs Olijnik

My research focuses on understanding the molecular basis of a rare type of anaemia called Congenital Dyserythropoietic Anaemia type I (CDA-I). This disease is due to abnormal erythropoiesis where erythroblasts cannot mature into erythrocytes. CDA-I patients show a wide range of symptoms; some can have a life-long dependency on transfusion while others will have less severe symptoms. Diagnosis relies on analysing bone-marrow aspirate by looking for inter-nuclear bridges and bi-nucleated or multinucleated erythroblasts and electron microscopy shows a characteristic pattern of spongy (“Swiss cheese”) heterochromatin in the erythroblast nucleus.

Our lab has previously identified a gene mutated in some CDA-I patients that codes for the protein C15orf41. There is a second protein also involved in CDA-1 called Codanin-1. These two proteins are localised predominantly in the nucleoli and are hypothesised to have a role in the resolution of abnormal chromatin structures. My work focuses on deciphering the role of these proteins during normal erythropoiesis and how mutant versions impact the differentiation of erythroblasts.

I am using a cell line called HUDEP-2 (Human Umbilical cord-Derived Erythroid Progenitor-2) to study the function of C15orf41 and Codanin-1 at different stages of erythropoiesis. 
To assist in this aim I am engineering an endogenously tagged version of C15orf41 in HUDEP-2 cells using CRISPR-Cas9 technology and am introducing patient mutations into this cell line to establish a cellular model for the disease.
Since neither protein is abundant in the cell, I have developed a protocol for 2-colour Infrared-Western Blotting of lowly expressed proteins to study Codanin-1 and C15orf41 in HUDEP-2 cells and in primary CD34+ cells.

As an additional project, I am looking for biomarkers for CDA-1 that could give a more reliable and more rapid diagnosis than microscopic studies. Such a biomarker could also facilitate screening for improved therapies for this serious disease.