Dr Neil Chapman, B.Sc.(Hons.), Ph.D., P.G.Cert.H.E., F.H.E.A.
Group Leader and Non-Clinical Lecturer in Reproductive Medicine
The Department of Human Metabolism,
Academic Unit of Reproductive & Developmental Medicine,
Level 4, The Jessop Wing,
Tree Root Walk,
Telephone 0114 226 8530
I joined the University of Sheffield as a Group Leader and Non-Clinical Lecturer in Reproductive Medicine in July 2005. Previous research positions included:
- October 2003 - June 2005
Post-Doctoral Research Associate, School of Surgical and Reproductive Sciences, University of Newcastle-upon-Tyne. Research: Transcriptional regulation in the myometrium and cervix by the Nuclear Factor kappaB (NF-kappaB) and novel membrane-bound steroid receptors.
- June 1997 - September 2003
Post-Doctoral Research Associate, School of Life Sciences, Division of Gene Expression and Regulation, Wellcome Trust Biocentre, University of Dundee. Research: Transcriptional regulation by NF-kappaB; determining how NF-kappaB regulates mammalian gene expression in conjunction with other proteins (Egr-1, WT-1, CBP/p300 and c-Myc) with an emphasis on tumourigenesis.
- September 1994 - May 1997
May 1997 Ph.D. student, University of Sheffield. Research: Expression and characterisation of the ZP3 protein; to develop purification strategies to isolate recombinant copies of ZP3 and then characterise their effects on human spermatozoa.
Research Interests and Current Projects
My research interests focus on gene regulation by the nuclear factor kappaB family of transcription factors. I am involved with the following projects:
- Developing the chromatin immunoprecipitation assay-Next Generation Sequencing methodology (ChIP-seq) genomic regions within the human myometrium influenced by NF-kappaB. This was Vicky Cookson's original Ph.D. project and has now evolved into a multi-centre study involving Dr. Paul Hurd, Queen Mary University of London and Profs. Magnus Rattray and Neil Lawrence, University of Sheffield.
- Defining cross-talk between NF-kappaB and Galphas signalling pathways in the human myometrium.
- Examining how inflammatory mediators regulate T-type calcium channel expression in the human decidua (in collaboration with Dr. Raheela Khan, University of Nottingham at Derby).
- Developing a system to test novel tocolytic compounds (drugs which can prevent pre-term labour; a multi-centre study with Prof. Nick Europe-Finner and Prof. Mike Taggart, University of Newcastle-upon-Tyne and Prof. Bryan Mitchell, University of Alberta at Edmonton).
- Developing the MeDIP assay to investigate epigenetic changes in human spermatozoa (with Sarah Waite and Dr. Allan Pacey).
- Studying the role of NF-kappaB in muscular dystrophy (collaboration with Dr. Gaynor Miller).
- Understanding the role of Toll-like receptors in the pregnant human cervix (with Dilly Anumba; Behnia Lashkari's Ph.D. project).
Research Background: Molecular Biology of Myometrial Function during Pregnancy and Labour
Importance of Research into Premature Labour:
In the developed world, premature birth complicates 6-10% of pregnancies. As a nation, England has the highest incidence of premature birth in Europe with 42,500 pre-term deliveries recorded in 2003-2004 (Maternity Statistic, England, Department of Health May 2003-2004). In the U.S.A., 500,000 preterm births were recorded in 2003-2004, while hospital charges for 25,000 infant admissions with a primary diagnosis of premature birth totalled $1.9 billion in 2003. Significantly, the incidence of birth before 28 weeks gestation (severely preterm) is increasing with those infants having elevated risks of major long-term mental and physical handicap. Moreover, such infants have a disproportionate effect on health-care budgets world-wide: a recent U.K. estimate of the total cost of preterm birth to the public sector was £2.95 billion. Current tocolytic therapies (treatments used to stop premature myometrial contractions), however, have limited use and are associated with complications for both infant and mother. Since the antenatal health of a baby is seen as a major predictor of adult morbidity, reducing the incidence of premature birth is paramount considering the soaring costs of health care for such adult diseases. Please read the AMR Tiny Lives Charter and the March of Dimes White Paper from the Download box for further information on pre-term birth.
The Myometrial Galphas/cAMP/PKA Pathway:
One of the most significant physiological adaptations of the uterus to pregnancy is the development of a relative state of myometrial smooth muscle inactivity termed quiescence. At the onset of labour the state of myometrial quiescence ends and a series of powerful uterine contractions act to expel the infant. There is growing evidence indicating that components of the cyclic AMP (cAMP) signalling pathway are differentially expressed in the human myometrium during pregnancy thereby potentiating the maintenance of uterine quiescence until term. These include calcitonin gene related peptide (CGRP) receptors, chorionic gonadotrophin/LH receptors and the adenylyl cyclase stimulatory G-protein Galphas, whose levels of expression are considerably increased within the myometrium during gestation causing an increased production of cAMP and activation of protein kinase A (PKA); these factors are subsequently reduced in labour. The mechanism by which down-regulation of Galphas expression occurs, however, remains unclear, although recently it was reported that the Galphas promoter was regulated by Sp-like transcription factors requiring phosphorylation by PKA.
Molecular Biology of Myometrial Function
Regulatory networks between cell signalling molecules, transcription factors and DNA ensure cells function normally. One set of transcription factors which govern a wide variety of cellular activities are the nuclear factor kappaB (NF-kappaB) family of proteins. In humans, a number of pro-inflammatory cytokines and inducible factors, associated with the onset of both normal and preterm labour, are regulated by NF-kappaB including TNFalpha, IL-1beta, IL-8 and COX-2 in all gestational tissues examined, including the myometrium. These studies, however, concentrate on well characterised NF-kappaB-responsive promoters in isolation: a poor reflection of the events likely to occur in vivo.
NF-kappaB, which is rapidly induced by over 400 different stimuli including TNFalpha cytokines and growth factors, is present in virtually every cell type within the body. NF-kappaB can take a number of different forms and is composed of dimeric complexes formed from five distinct subunits (See NF-kappaB Figures; Figure 1 available from the Download Box): RelA (p65), RelB and c-Rel (which contain transactivation domains within their c-termini) and NF-kappaB1 (p105/p50) and NF-kappaB2 (p100/p52) which undergo proteolysis to yield the DNA-binding isoforms, p50 and p52 which lack transactivation domains. Combinations of subunits determine the specificity of transcriptional activation and all have distinct, non-overlapping functions. The consensus NF-kappaB binding site is generally viewed as 5´-GGGRNYYYCC-3´ (where R = A or G; N = A, C, T or G and Y = C or T) although there are a great many functional variations on this and it is estimated that there are in excess of 3000 kappaB sites within the human genome. The figure to the left illustrates the N-terminal domain of the mouse RelA homodimer bound to DNA. This was resolved by Gourisanker Ghosh at the University of California at San Diego (see Chen et al. (1998). Nature Structural Biology 5: 67-73).)
In the majority of unstimulated cell types, NF-kappaB is retained within the cytoplasm in an inactive form, bound to its inhibitor protein, IkappaB (See NF-kappaB Figures; Figure 2 available from the Download Box). NF-kappaB can be activated in at least two ways. In the first, or canonical, pathway, cytokines, such as TNFalpha and IL-1beta, cause phosphorylation of IkappaB kinase (IKK) ultimately releasing p50:RelA and/or p52/RelA heterodimers. The second, non-canonical, pathway utilises IKKalpha-induced phosphorylation and processing of p100 to p52 generating mainly p52:RelB heterodimers which transactivate a different subset of genes. Atypical modes of activation, including that induced by hypoxic insult, stimulate NF-kappaB through methods that often do not rely on degradation of the IkappaB complex. In addition to the variety of homo- and heterodimers formed, these proteins undergo post translational modifications such as phosphorylation and acetylation and can recruit a range of other regulatory proteins and transcription factors to the enhancer/repressor region. Together with the inherent architecture of the enhancer/promoter itself, a number of opportunities therefore arise for highly specific gene expression in response to a given stimulus.
NF-kappaB and the Myometrium
The human myometrium is a complex tissue: previous work in my lab has demonstrated that NF-kappaB expression occurs in a spatio-temporal fashion. As such, it is highly likely that NF-kappaB -regulated genes will be governed in a similar manner to ensure parturition occurs at the correct juncture.
My lab has also defined an association between RelA and the catalytic subunit of PKA in pregnant myometrial homogenates suggesting there may be cross-talk between NF-kappaB and the cAMP/PKA pathways within the myometrium. Significantly, elevation of cAMP and activation of PKA have been shown to inhibit NF-kappaB-mediated transcription in a number of non-myometrial cell lines. This thesis, however, is further complicated by reports detailing an association between RelA and PKA, with PKA being required to activate NF-kappaB DNA-binding in a cAMP-independent fashion. Furthermore, TNFalpha can reduce cAMP levels in cardiac myocytes analogous to that seen in the labouring myometrium. Consequently, my lab work focuses on how inflammatory mediators within the pregnant uterus and decidua work through NF-kappaB to reduce Galphas expression and subsequently induce parturition.
My group aims to employ the very latest molecular technologies to decipher the molecular and cellular biology of the events which govern human pregnancy and labour. In turn, this will provide a foundation to develop tocolytics which are more effective clinically and safer for both mother and her child.
Research Funding Awarded
Over the last four years I have been either Principal or co-applicant on eight major research grants totalling £1,021,521 from the following sources:
- July 2010 - June 2011
University of Sheffield, Faculty of Medicine Dentistry and Health Research and Innovation Fund; £5,000 (Chapman, Webster, Heath and Waite).
- July 2010 - June 2011
University of Sheffield, Faculty of Medicine Dentistry and Health Research and Innovation Fund; £5,000 (Miller and Chapman).
- July 2009 - September 2011
Medical Research Council; £228,012 (Europe-Finner, Taggart, Chapman and Mitchell).
- October 2008 - September 2011
Medical Research Council; £447,201 (Chapman, Anumba, Europe-Finner and Khan).
- October 2008 - September 2011
The Wellcome Trust; £278,309 (Khan and Chapman).
- October 2007 - September 2009
Sheffield Hospitals Charitable Trust; £49,999 (This includes Ph.D. student Stipend; Chapman, Anumba, Heath and Cookson).
- March 2007 - March 2008
University of Sheffield Medicine Division Devolved Fund; £5,000 (Chapman).
- July 2006 – December 2006
Jessop Wing Small Grants Fund; £3,000 (Chapman and Anumba).
My teaching interests include the molecular biology and physiology of parturition and gene regulationn to both undergraduate and post-graduate students. I am involved with the following courses:
Teaching - Undergraduate Medical Curriculum
- I provide lab-based projects for the Phase 1B research SSC. Please read the Phase 1B SSC placement outline available from the Download box for further details of this attachment.
- I present lectures to the Phase 3A undergraduate medical students entitled The Physiology of Pregnancy and Parturition.
- Together with a clinical colleague, I also co-supervise a Phase 3A SSC project introducing student doctors to mountain rescue. This is through my membership of Edale Mountain Rescue Team and students undertaking this placement work closely with all rescue team members to gain a full insight into the workings of the rescue team. If you are a student doctor with an interest in this area, please have a read of the Phase 3A placement outline available from the download box above and, if interested, contact me in the first instance regarding this project.
- I serve as an academic mentor to nine student doctors at various phases of their medical studies.
Teaching - Post-Graduate Studies
- My first Ph.D. student, Vicky Cookson, was awarded her Ph.D. in February 2011. She is now a CRUK-funded Post-Doctoral Research Associate at the University of Leeds.
- I am primary supervisor one Ph.D. student (Sarah Waite) and second supervisor for a further student (Behnia Lashkari).
- I am a member of the Part-1 MRCOG examination sub-committee and so am responsible for preparing and editing questions relating to molecular biology, biochemistry and genetics for this international post-graduate medical examination.
- External Ph.D. examiner to the University of Newcastle-upon-Tyne.
- I am Module Lead for the Clinical Nutrition module of the Masters Course in Human Nutrition provided by the Academic Unit of Human Nutrition.
- I lecture on the Masters Course in Human Nutrition gving a seminar entitled Physiological Changes of Pregnancy.
- I have served as internal examiner for M.Phil. transfer reports where appropriate.
- I have served as a project marker for the M.Sc. in Molecular Medicine.
- I have presented ad hoc sessions discussing The Molecular Biology of Human Parturition to post-graduate medical trainees.
Professional Activities and Factors of Esteem
- Member of the MRCOG Part 1 examination Sub-committee of the Royal College of Obstetricians and Gynaecologists October 2007-May 2011.
- Expert Panel Member on the Action Medical Research Stand Up for Tiny Lives Steering Committee. This group presented its Tiny Lives Charter to the House of Commons in July 2008.
- Regularly invited to give research seminars; most recently at King’s College, London (September 2009) and The University of Newcastle-upon-Tyne (November 2009).
- Regularly invited to review funding applications to the MRC, NC3Rs, Wellbeing for Women, Action Medical Research amongst others.
- Regularly review papers prior to publication for Molecular Human Reproduction and Molecular Pharmacology.
Members of the Group
- Sarah Waite (Ph.D. Student and Senior Research Technician)
- Steve Webster (Post-Doctoral Research Associate)
Awards to Group Members
Congratulations to Vicky Cookson who successfully defended her theis and was awarded her Ph.D. on February 4th. Well done Dr. Cookson; a fantastic achievement!
Congratulations to Sarah Waite, the Senior Research Technician in my group, who has is now a full Member of the Institute of Science and Technology.
Congratulations to Vicky Cookson for winning in excess of £3,000 in funding from the Funds for Women Graduates scheme.
Congratulations to Vicky Cookson, my first Ph.D. student, who won first prize in the Medical School's third year Ph.D. seminar programme in May 2009: well done, Vicky!