Elucidation of the molecular basis of BMP1 inhibition by its endogenous inhibitor and development of an anti-fibrotic molecule

REMOD-HEALING is a research network of leading European and Latin American scientists from academia and industry, who want to tackle the burden of pathological wounds by exploiting therapeutic targets and biomarkers associated with extracellular matrix remodelling in cutaneous wounds. Through its research and training activities, the REMOD-HEALING project will contribute to scientific advancement and innovation in wound healing and regenerative medicine through a coordinated, interdisciplinary effort, ultimately leading to societal and economic benefits (more information here: remod-healing.eu).

The thesis project at LBTI is entitled "Elucidation of the molecular basis of BMP1 inhibition by its endogenous inhibitor and development of an anti-fibrotic molecule" and is described below.

Introduction

BMP1 (Bone Morphogenetic Protein 1) is an extracellular metalloprotease playing critical roles in extracellular matrix assembly and growth factor activation (1). It is involved in several physiological processes such as development, growth and skin wound healing. The dysregulation of its activity can however lead to pathological conditions, including wound healing disorders (e.g. chronic wounds and scarring). The lab of C. Moali is interested in understanding the mechanisms of regulation of BMP1 activity, at the molecular, cellular and tissue levels, with the goal to develop innovative therapeutic approaches to treat wound healing disorders.

Background

Previous work has shown that BMP1 regulation relies on two main proteins, PCPE1 and PCPE2, with both overlapping and divergent functions. One major difference between the PCPE proteins is that only PCPE2 can inhibit BMP1 proteolytic activity (2, 3). This finding was unexpected because PCPE1 and PCPE2 are very similar in terms of sequences and structures.

Objectives

The main objectives of the PhD project will be (i) to elucidate the molecular basis of BMP1 inhibition by PCPE2 and (ii) to use this knowledge to design an anti-fibrotic molecule capable of blocking collagen proteolytic maturation by BMP1.

Methodology

We will use systematic sequence swapping between PCPE1 and PCPE2 to identify the important residues for PCPE2 inhibitory function (molecular biology, activity assays, surface plasmon resonance). In parallel, we will try to solve the structure of the BMP1/PCPE2 complex by cryo-electron microscopy with the help of previously developed Nanobodies^® to stabilize flexible regions. Finally, we will engineer an optimized inhibitor of BMP1 with high potency, stability and specificity and test its therapeutic potential in a wound-on-a-chip model of skin scarring.

Expected Results

This project will lead to the elucidation of a new mechanism of protease inhibition and to the development of a specific and potent inhibitor of BMP1 with anti-fibrotic properties.