Connective tissues are dynamic systems, which are continually undergoing change throughout development and adult life. Connective tissue homeostasis (the biosynthesis, deposition, degradation and turnover of extracellular matrix (ECM) molecules is controlled primarily by the major resident cell type and their response to stimuli such as specific cytokines, growth factors and surface receptors. The turnover of ECM is regulated by proteolytic enzymes including metzencin family of enzymes as well as others. We are using transgenic approaches to investigate the dis-regulation of the ECM synthesis and breakdown that lead to two opposing pathology aspects of connective tissue.
We are interested in understanding the normal physiology and pathologies of connective tissue diseases such as:
1. Alkaptonuria (AKU): Alkaptonuria is a metabolic disorder of tyrosine pathway due to deficiency of homogentisate 1,2 dioxygenase (HGD) resulting in accumulation of homogentisic acid (HGA) causing black urine, leading to deposition of melanin-like HGA-pigment in connective tissues. My lab is part of a larger group of people including the Centre of AKU at the Royal Liverpool Hospital who are working with the Alkaptonuria Society to treat this disease.
A tenure track Fellowship for Dr Brendan Norman (below) is also awarded to develop new therapies for Tyrosineamia. We are also grateful to the Gregory family who donated 40K as part funding for a studentship in gene therapy of AKU and Rebecca Brown was appointed as new PhD student.
2. Fibrosis In fibrosis the repair process that include synthesis and deposition of new components is impaired for unknown reason. Accompanying these events is a fundamental genetic reprogramming of the resident cell, the fibroblast, resulting in differential expression of matrix modulating enzymes such as metalloproteinases (MMPs) and their inhibitors (TIMPs). We are investigating the effect of genes that influence that balance in gain and loss of function experiments to readdress the balance by using collagen type I specific enhancer to target cells that produce collagen in fibrotic conditions.
3. Osteoarthritis (OA) is the most common form of joint disease, characterized by the progressive destruction of articular cartilage matrix. We are taking a broad view at the whole synovial joints from synovium, ligaments, bone and articular cartilage to investigate what goes wrong in OA and way to ameliorate the disease. In particular, AKU patients where calcified cartilage showed ochronosis.
Institute Collaboration We are fortunate to have great colleagues at the Institute who are happy to collaborate. We are using non-invasive loading technique to induce OA with Dr Blandine Poulet (Curr Rheumatol Rep (2016) 18: 40). We are taking advantage of the LRP1 uptake of degradative enzymes with Dr Kazu Yamamoto (Arthritis Rheumatol 69(6), 1246-1256, 2017) to ameliorate the disease progression. We are collaborating with Dr Simon Tew to investigate RNA stability in an in vivo models. Our most adventurous collaboration is with Dr Kris D' Aout using biplanar X-Ray based gait analysis for minimally invasive detection of knee osteoarthritis in mouse models. We have ventured into the Dental school with collaborators such as Prof. Fadi Jarrad and Dr Nick Longridge. Last but not least. I am grateful to my clinical colleagues Lisa Spencer, Rob Moots and Sonya Craig for keeping our interest in pulmonary disease focused on the patients.
External Collaborators Francesco Ramirez ( Mount Sinai, NY), Andy Pitsillides (Professor of Skeletal Dynamics, The Royal Veterinary College, UCL), Dr Sarah De Val (Ludwig Institute for Cancer Research, University of Oxford), David Abraham (Professor of Cell and Molecular Biology, UCL- Royal Free Campus), Professor David Young and Dr Louise Reynard (Newcastle University), Dr Andrew Leask and Dr Cheryle Seguin (University of Western Ontario, Canada). Funding from the Sasakawa foundation allowed us to explore collaboration with colleagues in Japan and our first visit was to Kanazawa and Okayama where we had great talks about strengthening our ties (see photos below)
Career progression of individuals from my lab: Ian M LI, my first student in Liverpool, finished his PhD and joined a post-doctoral training program at Harvard and moved to industry. Amy Horwell and Kirsty Johnston joined AstraZeneca. Caroline Cotton defended her PhD and became a registrar at Aintree Hospital, Stephanie Frost is a Post-doc at QMC, London. Ioannis Kanakis, moved to Chester University as senior lecturer. Dr Juliette Hughes and Dr Graig Keenan were appointed lecturers at Edge Hill University. Dr Ooi went back to Japan to head a research group. More recently, Conor Sugden went for a post-doc in Spain. Mohammad Al Hashmi (left, with the commemorative T-shirt) went back to take a new position in Saudi Arabia. Dominic took a Post-doc position in Newcastle University. Sara Al Salhi went back to the kingdm of Saudi Arabia.
Recent Peer reviewed papers:
Alhashmi M, Gremida AME, Maharana SK, Antonaci M, Kerr A, Fu S, Lunn S, Turner DA, Al-Maslamani NA, Liu K, Meschis MM, Sutherland H, Wilson P, Clegg P, Wheeler GN, van 't Hof RJ, Bou-Gharios G, Yamamoto K Skeletal progenitor LRP1 deficiency causes severe and persistent skeletal defects with Wnt pathway dysregulation. Bone Res. 2025 Jan 26;13(1):17.
Ranganath LR, Khedr M, Norman BP, Hughes JH, Imrich R, Arnoux JB, Olsson B, Rudebeck M, Gallagher JA, Bou-Gharios G. Joint replacement risk is markedly increased in alkaptonuria (AKU) in those with prior arthroplasty. Mol Genet Metab Rep. 2024 May 24;40:101097.
Neuckermans J, Lequeue S, Claes P, Heymans A, Hughes JH, Colemonts-Vroninks H, Marcélis L, Casimir G, Goyens P, Martens GA, Gallagher JA, Vanhaecke T, Bou-Gharios G, De Kock J. Hereditary Tyrosinemia Type 1 Mice under Continuous Nitisinone Treatment Display Remnants of an Uncorrected Liver Disease Phenotype. Genes (Basel). 2023 Mar 11;14(3):693
Quan T, Xia W, He T, Calderone K, Bou-Gharios G, Voorhees JJ, Dlugosz AA, Fisher GJ. Matrix Metalloproteinase-1 Expression in Fibroblasts Accelerates Dermal Aging and Promotes Papilloma Development in Mouse Skin. J Invest Dermatol. 2023 Mar 11:S0022-202X(23)01827-4
Ranganath LR, Hughes AT, Davison AS, Khedr M, Imrich R, Rudebeck M, Olsson B, Norman BP, Bou-Gharios G, Gallagher JA, Milan AM. Revisiting Quantification of Phenylalanine/Tyrosine Flux in the Ochronotic Pathway during Long-Term Nitisinone Treatment of Alkaptonuria. Metabolites. 2022 Sep 29;12(10):920
Norman BP, Davison AS, Hickton B, Ross GA, Milan AM, Hughes AT, Wilson PJM, Sutherland H, Hughes JH, Roberts NB, Bou-Gharios G, Gallagher JA, Ranganath LR. Comprehensive Biotransformation Analysis of Phenylalanine-Tyrosine Metabolism Reveals Alternative Routes of Metabolite Clearance in Nitisinone-Treated Alkaptonuria. Metabolites. 2022 Sep 29;12(10):927
Yamamoto K, Scavenius C, Meschis MM, Gremida AME, Mogensen EH, Thøgersen IB, Bonelli S, Scilabra SD, Jensen A, Santamaria S, Ahnström J, Bou-Gharios G, Enghild JJ, Nagase H. A top-down approach to uncover the hidden ligandome of low-density lipoprotein receptor-related protein 1 in cartilage. Matrix Biol. 2022 Aug 23:S0945-053X(22)00101-9
Knox J, Bou-Gharios G, Hamill KJ, Willoughby CE. MiR-18a-5p Targets Connective Tissue Growth Factor Expression and Inhibits Transforming Growth Factor β2-Induced Trabecular Meshwork Cell Contractility. Genes (Basel). 2022 Aug 22;13(8):1500
Ranganath LR, Milan AM, Hughes AT, Davison AS, Khedr M, Imrich R, Rudebeck M, Olsson B, Norman BP, Bou-Gharios G, Gallagher JA. Comparing the Phenylalanine/Tyrosine Pathway and Related Factors between Keratopathy and No-Keratopathy Groups as Well as between Genders in Alkaptonuria during Nitisinone Treatment. Metabolites. 2022 Aug 22;12(8):772
Ranganath LR, Hughes AT, Davison AS, Khedr M, Olsson B, Rudebeck M, Imrich R, Norman BP, Bou-Gharios G, Gallagher JA, Milan AM. Temporal adaptations in the phenylalanine/tyrosine pathway and related factors during nitisinone-induced tyrosinaemia in alkaptonuria. Mol Genet Metab. 2022 Jun 1:S1096-7192(22)00325
Sugden CJ, Iorio V, Troughton LD, Liu K, Morais MRPT, Lennon R, Bou-Gharios G, Hamill KJ. Laminin N-terminus α31 expression during development is lethal and causes widespread tissue-specific defects in a transgenic mouse model. FASEB J. 2022 Jul;36(7):e22318
Roebuck MM, Jamal J, Lane B, Wood A, Santini A, Wong PF, Bou-Gharios G, Frostick SP. Cartilage debris and osteoarthritis risk factors influence gene expression in the synovium in end stage osteoarthritis. Knee. 2022 Jun 6;37:47-59.
Ramos-Mucci L, Elsheikh A, Keenan C, Eliasy A, D'Aout K, Bou-Gharios G, Comerford E, Poulet B. The anterior cruciate ligament in murine post-traumatic osteoarthritis: markers and mechanics. Arthritis Res Ther. 2022 May 30;24(1):128.
Tam AYY, Horwell AL, Trinder SL, Khan K, Xu S, Ong V, Denton CP, Norman JT, Holmes AM, Bou-Gharios G, Abraham DJ. Selective deletion of connective tissue growth factor attenuates experimentally-induced pulmonary fibrosis and pulmonary arterial hypertension. Int J Biochem Cell Biol. 2021 May;134
Wilson PJM, Ranganath LR, Bou-Gharios G, Gallagher JA, Hughes JH. Expression of tyrosine pathway enzymes in mice demonstrates that homogentisate 1,2-dioxygenase deficiency in the liver is responsible for homogentisic acid-derived ochronotic pigmentation. JIMD Rep. 2020 Nov 12;58(1):52-60
Johnson de Sousa Brito FM, Butcher A, Pisconti A, Poulet B, Prior A, Charlesworth G, Sperinck C, Scotto di Mase M, Liu K, Bou-Gharios G, Jurgen van 't Hof R, Daroszewska A. Syndecan-3 enhances anabolic bone formation through WNT signaling. FASEB J. 2021 Apr;35(4):e21246.
Hughes JH, Liu K, Plagge A, Wilson PJM, Sutherland H, Norman BP, Hughes AT, Keenan CM, Milan AM, Sakai T, Ranganath LR, Gallagher JA, Bou-Gharios G. Conditional targeting in mice reveals that hepatic homogentisate 1,2-dioxygenase activity is essential in reducing circulating homogentisic acid and for effective therapy in the genetic disease alkaptonuria. Hum Mol Genet. 2019 Oct 10. pii:ddz234.
Hughes JH, Wilson PJM, Sutherland H, Judd S, Hughes AT, Milan AM, Jarvis JC, Bou-Gharios G, Ranganath LR, Gallagher JA. Dietary restriction of tyrosine and phenylalanine lowers tyrosinaemia associated with nitisinone therapy of alkaptonuria. J Inherit Metab Dis. 2019 Sep 10. ahead of print] PubMed PMID: 31503358.
Scavenius C, Poulsen EC, Thøgersen IB, Roebuck M, Frostick S, Bou-Gharios G, Yamamoto K, Deleuran B, Enghild JJ. Matrix-degrading protease ADAMTS-5 cleaves inter-α-inhibitor and release active heavy chain 2 in synovial fluids from arthritic patients. J Biol Chem. 2019 Sep 4. pii: jbc.RA119.008844.
Davison AS, Strittmatter N, Sutherland H, Hughes AT, Hughes J, Bou-Gharios G, Milan AM, Goodwin RJA, Ranganath LR, Gallagher JA. Assessing the effect of nitisinone induced hypertyrosinaemia on monoamine neurotransmitters in brain tissue from a murine model of alkaptonuria using mass spectrometry imaging. Metabolomics. 2019 Apr 29;15(5):68.
Neal A, Nornes S, Payne S, Wallace MD, Fritzsche M, Louphrasitthiphol P, Wilkinson RN, Chouliaras KM, Liu K, Plant K, Sholapurkar R, Ratnayaka I, Herzog W, Bond G, Chico T, Bou-Gharios G, De Val S. Venous identity requires BMP signalling through ALK3. Nat Commun. 2019 Jan 28;10(1):453
Kanakis I, Liu K, Poulet B, Javaheri B, van 't Hof RJ, Pitsillides AA, Bou-Gharios G. Targeted Inhibition of Aggrecanases Prevents Articular Cartilage Degradation and Augments Bone Mass in the STR/Ort Mouse Model of Spontaneous Osteoarthritis. Arthritis Rheumatol. 2018 Oct 31. doi: 10.1002/art.40765.
Li IMH, Liu K, Neal A, Clegg PD, De Val S, Bou-Gharios G. Differential tissue specific, temporal and spatial expression patterns of the Aggrecan gene is modulated by independent enhancer elements. Sci Rep. 2018 Jan 17;8(1):950.
Frost SL, Liu K, Li IMH, Poulet B, Comerford E, De Val S, Bou-Gharios G. Multiple enhancer regions govern the transcription of CCN2 during embryonic development. J Cell Commun Signal. 2018 Mar;12(1):231-243
Chiang IK, Fritzsche M, Pichol-Thievend C, Neal A, Holmes K, Lagendijk A, Overman J, D'Angelo D, Omini A, Hermkens D, Lesieur E, Fossat N, Radziewic T, Liu K, Ratnayaka I, Corada M, Bou-Gharios G, Tam PPL, Carroll J, Dejana E, Schulte-Merker S, Hogan BM, Beltrame M, De Val S, Francois M. Correction: SoxF factors induce Notch1 expression via direct transcriptional regulation during early arterial development. Development doi: 10.1242/dev.146241. Development. 2017 Oct 15;144(20):3847-3848..
Li IMH, Horwell AL, Chu G, de Crombrugghe B, Bou-Gharios G. Characterization of Mesenchymal-Fibroblast Cells Using the Col1a2 Promoter/Enhancer. Methods Mol Biol. 2017;1627:139-161.
Miller B, Spevak L, Lukashova L, Javaheri B, Pitsillides AA, Boskey A, Bou-Gharios G, Carriero A. Altered Bone Mechanics, Architecture and Composition in the Skeleton of TIMP-3-Deficient Mice. Calcif Tissue Int. 2017 Jun;100(6):631-640. doi: 10.1007/s00223-017-0248-5.
Poulet B, Liu K, Plumb D, Vo P, Shah M, Staines K, Sampson A, Nakamura H, Nagase H, Carriero A, Shefelbine S, Pitsillides AA, Bou-Gharios G. Overexpression of TIMP-3 in Chondrocytes Produces Transient Reduction in Growth Plate Length but Permanently Reduces Adult Bone Quality and Quantity. PLoS One. 2016 Dec 21;11(12):e0167971.
Sacilotto N, Chouliaras KM, Nikitenko LL, Lu YW, Fritzsche M, Wallace MD, Nornes S, García-Moreno F, Payne S, Bridges E, Liu K, Biggs D, Ratnayaka I, Herbert SP, Molnár Z, Harris AL, Davies B, Bond GL, Bou-Gharios G, Schwarz JJ, De Val S. MEF2 transcription factors are key regulators of sprouting angiogenesis. Genes Dev. 2016 Oct 15;30(20):2297-2309.
Javaheri B, Hopkinson M, Poulet B, Pollard AS, Shefelbine SJ, Chang YM, Francis-West P, Bou-Gharios G, Pitsillides AA. Deficiency and Also Transgenic. Overexpression of Timp-3 Both Lead to Compromised Bone Mass and Architecture In Vivo. PLoS One. 2016 Aug 12;11(8):e0159657.