Dr Jun Yan

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Research Interests

I am a senior research officer in Professor Pam McCombe and Dr Judith Greer's research groups.  My research interest is primarily investigating the mechanisms involved in disease development, diagnosis and treatment ischemic stroke (IS) and multiple sclerosis (MS).

There are two types of stroke: ischemic stroke and haemorrhagic stroke. Our study is primarily focused on ischemic stroke, as it is the most common type, comprising about 80% of all strokes. Ischemic stroke is resultant either from a blood clot (thrombus) blocking circulation or by a build-up of plaque within the arteries, narrowing vessels and resulting in a loss of blood flow. My primary research area is investigating the immune responses of peripheral lymphocytes post-ischemia. We would like to know if these immune responses contribute to either brain damage or tissue repair. We would also like to know how these immune responses are regulated genetically and the degree by which immune response correlates with clinical outcome.

My research area on MS focuses on exploring the NF-B signal transduction pathway in the development of the disease. MS is a chronic inflammatory, demyelinating and neurodegenerative disorder of the central nervous system (CNS). It is considered to be an autoimmune disease mediated primarily by CD4+ T cells, which are activated in the peripheral blood and migrate into the CNS.  The molecular basis of MS pathogenesis is not clear. Recent studies have shown that a transcription factor, NF-B, plays important role in autoimmune diseases progression and is involved in the activation of lymphocytes.

NF-kB is a ubiquitous transcription factor that plays an important role in controlling gene expression in inflammation, immunity, cell proliferation and apoptosis, and therefore we would like to know what role NF-B plays in MS. In mammals, NF-B comprises a family of five protein subunits, p50, p52, RelA (p65), c-Rel, and Rel-B.  In most resting cells, hetero- or homo- dimers of NF-B subunits are retained in an inactive form in the cytoplasm through association with an inhibitory protein, called IB. Exposure of cells to a variety of stimuli leads to the rapid phosphorylation, ubiquitination, and ultimately proteolytic degradation of IB, which frees NF-B to translocate to the nucleus and initiate gene transcription. We wish to determine if this pathway is dysregulated or impacted upon in MS.

 

Methodology in my studies:

  1. 1. Flow cytometry
  2. 2. T cell proliferation assays
  3. 3. Western blots
  4. 4. Immunocytochemistry
  5. 5. DNA sequencing
  6. 6. Tissue culture
  7. 7. Luciferase assays
  8. 8. DNA MicroArrays

 

Funding acknowledgement

MS Research Australia

Potential Honours Projects and Summer research scholarships:

To investigate if NF-kB is constitutively activated in different immune cell types from MS patients compared to healthy controls.

To investigate if mutations in NF-kB regulatory molecules correlate with MS.

To investigate NFKBIA promoter function in MS using in vitro luciferase assay.

 

 

Contact details and email

Dr Jun Yan (BSc, PhD)

Senior Research Officer

University of Queensland Centre for Clinical Research

Royal Brisbane and Women's Hospital

Herston, Brisbane, QLD

Australia 4029

 

Tel: 061-07-3346 6019

Fax: 061-07-3346 5594

E-mail: j.yan@uq.edu.au

 

Key publications:

Yan, J and JM Greer.  NF-κB, a Potential Therapeutic Target for the Treatment of Multiple Sclerosis.   (Review) CNS & Neurological Disorders - Drug Targets, 2008, 7, 536-557.


Yan, J et al  Immune activation in the peripheral blood of patients with acute ischemic stroke.  
J Neuroimmunol. 2009 Jan 3; 206(1-2):112-7.


Yan J et al The effect of aging on human lymphocyte subsets: comparison of males and females
Immunity & Ageing  2010, 7:4doi:10.1186/1742-4933-7-4


Yan J et al    Frequency and function of regulatory T cells after ischaemic stroke in humans: evidence of gender differences Increased numbers of functionally impaired CD4+CD25+Foxp3+ T cells after ischaemic stroke. Journal of Immunology (submitted)

Singh P., Yan J.,   eett al    Levelevels of phosphorylated axonal neurofilament subunit H (pNfH) are increased acute ischemic stroke. Journal of the Neurological Sciences  2011