Biomaterial Database

S100A8 & S100A9: Alarmin mediated inflammation in tendinopathy. 2019

Lindsay A N Crowe, and Michael McLean, and Susan M Kitson, and Emma Garcia Melchor, and Katharina Patommel, and Hai Man Cao, and James H Reilly, and William J Leach, and Brain P Rooney, and Simon J Spencer, and Michael Mullen, and Max Chambers, and George A C Murrell, and Iain B McInnes, and Moeed Akbar, and Neal L Millar

Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences University of Glasgow, Glasgow, Scotland, UK.

Alarmins S100A8 and S100A9 are endogenous molecules released in response to environmental triggers and cellular damage. They are constitutively expressed in immune cells such as monocytes and neutrophils and their expression is upregulated under inflammatory conditions. The molecular mechanisms that regulate inflammatory pathways in tendinopathy are largely unknown therefore identifying early immune effectors is essential to understanding the pathology. Based on our previous investigations highlighting tendinopathy as an alarmin mediated pathology we sought evidence of S100A8 & A9 expression in a human model of tendinopathy and thereafter, to explore mechanisms whereby S100 proteins may regulate release of inflammatory mediators and matrix synthesis in human tenocytes. Immunohistochemistry and quantitative RT-PCR showed S100A8 & A9 expression was significantly upregulated in tendinopathic tissue compared with control. Furthermore, treating primary human tenocytes with exogenous S100A8 & A9 significantly increased protein release of IL-6, IL-8, CCL2, CCL20 and CXCL10; however, no alterations in genes associated with matrix remodelling were observed at a transcript level. We propose S100A8 & A9 participate in early pathology by modulating the stromal microenvironment and influencing the inflammatory profile observed in tendinopathy. S100A8 and S100A9 may participate in a positive feedback mechanism involving enhanced leukocyte recruitment and release of pro-inflammatory cytokines from tenocytes that perpetuates the inflammatory response within the tendon in the early stages of disease.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015854	Up-Regulation	A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.	Receptor Up-Regulation,Upregulation,Up-Regulation (Physiology),Up Regulation
D016022	Case-Control Studies	Comparisons that start with the identification of persons with the disease or outcome of interest and a control (comparison, referent) group without the disease or outcome of interest. The relationship of an attribute is examined by comparing both groups with regard to the frequency or levels of outcome over time.	Case-Base Studies,Case-Comparison Studies,Case-Referent Studies,Matched Case-Control Studies,Nested Case-Control Studies,Case Control Studies,Case-Compeer Studies,Case-Referrent Studies,Case Base Studies,Case Comparison Studies,Case Control Study,Case Referent Studies,Case Referrent Studies,Case-Comparison Study,Case-Control Studies, Matched,Case-Control Studies, Nested,Case-Control Study,Case-Control Study, Matched,Case-Control Study, Nested,Case-Referent Study,Case-Referrent Study,Matched Case Control Studies,Matched Case-Control Study,Nested Case Control Studies,Nested Case-Control Study,Studies, Case Control,Studies, Case-Base,Studies, Case-Comparison,Studies, Case-Compeer,Studies, Case-Control,Studies, Case-Referent,Studies, Case-Referrent,Studies, Matched Case-Control,Studies, Nested Case-Control,Study, Case Control,Study, Case-Comparison,Study, Case-Control,Study, Case-Referent,Study, Case-Referrent,Study, Matched Case-Control,Study, Nested Case-Control