Faculty of Biological Sciences

Dr Jessica Kwok

PhD
University Academic Fellow in Medical Engineering in the Spinal Cord
School of Biomedical Sciences

Background: A neuro-/glyco-biologist focusing on enhancing plasticity for CNS pathologies. BSc in Biochemistry - University of Hong Kong (Hong Kong). PhD in Biochemistry - University of Hong Kong (Hong Kong). Postdoctoral scientist - University of Cambridge (UK). Visiting scientist - University of Grenoble Alpes (France).

Contact:  Garstang 5.55f, +44(0) 113 34 39802, email address for  

Research Interests

The role of chondroitin sulphates and perineuronal nets in spinal cord injury and memory

 

We aim to decipher the role of chondroitin sulphates (CSs) for a multitude of pathologies in the central nervous system (CNS), including spinal cord injury, ageing, memory and neurodegeneration.

Chondroitin sulphates in the central nervous system

Chondroitin sulphates belong to the family of glycosaminoglycans (GAGs). CSs are covalently bound to a core proteoglycans forming chondroitin sulphate proteoglycans (CSPGs), which are abundant in cartilage and CNS. In the CNS, CSPGs are strongly up-regulated after spinal cord injury in a structure called glial scar. Removal of CSs in the glial scar promotes neuronal regeneration.

CS in the perineuronal nets 

CS, apart from being strongly up-regulated after CNS injury, are also present in a structure called perineuronal nets (PNNs). PNNs are a layer of aggregated extracellular matrix, composed of CSPGs, link proteins and hyaluronan wrapping around the surface of sub-populations of neurons. Emerging evidence demonstrated that PNNs are important in controlling plasticity during development and regeneration. My research is mainly focused on understanding the structure of the PNNs, how they control plasticity and how to improve plasticity by PNN manipulation.             

 

 The Compositions and binding partners of PNNs

molecular composition of PNNs controls their properties, functions and binding partners. We have previously shown that the sulphation pattern of CSs in the PNNs is different from the pattern in the general brain extracellular matrix. CS-E isoforms are enriched in the PNN structure and controls the binding of semaphorin 3A to neurons. Semaphorin 3A is a repulsive guidance molecule, and its binding to PNN potentiate the inhibitory nature of PNNs.             

 

Faculty Research and Innovation



Studentship information

Undergraduate project topics:

  • Projects in all of the above areas are available. Enthusiastic and committed students are encouraged to contact me via email: j.kwok@leeds.ac.uk

Postgraduate studentship areas:

  • Enthusiastic and committed students are encouraged to contact me via email: j.kwok@leeds.ac.uk

See also:

Modules taught

BIOL5294M - MSc Bioscience Research Project Proposal
BIOL5392M - Bioscience MSc Research Project
BMSC1213 - Basic Laboratory and Scientific Skills 2
BMSC3301 - Research Project in Biomedical Sciences
BMSC5301M - Advanced Research Topics

Group Leader Dr Jessica Kwok  (University Academic Fellow in Medical Engineering in the Spinal Cord)

The role of chondroitin sulphates and perineuronal nets in spinal cord injury and memory 

Postgraduates

Sian Irvine (Primary supervisor) 90% FTE
Luke Souter (Primary supervisor) 50% FTE
Trang Nguyen (Co-supervisor) 20% FTE
Katherine Timms (Co-supervisor) 13% FTE