Biology subjects

Kendal, A. R.

Publications and source records attributed to Kendal, A. R..

2 recordsLinked to original sources

bioRxiv2021

Combined single cell proteomics and transcriptomics reveals discrete human tendon cells populations persist in vitro and on fibrous scaffolds

Chronic tendinopathy represents a growing burden to healthcare services in an active and ageing global population. The ability to identify, isolate and interrogate, in vitro, key pathogenic and reparative tendon cell populations is essential to developing precision therapies and implantable materials. Human hamstring tendon cells were cultured for 8 days on either tissue culture plastic or aligned electrospun fibres made of polydioxanone (absorbable polymer). Combined single cell surface proteomics and unbiased single cell transcriptomics (CITE-Seq) revealed six discrete cell clusters, four of which shared key gene expression determinants with ex vivo human cell clusters. These were PTX3_PAPPA, POST_SCX, DCN_LUM and ITGA7_NES cell clusters. Surface proteomics found that PTX3_PAPPA cells were CD10+CD26+CD54+. ITGA7_NES cells were CD146+, and POSTN_SCX cells were CD90+CD95+CD10+. Three clusters preferentially survived and proliferated on the aligned electrospun fibres; DCN_LUM, POSTN_SCX, and PTX3_PAPPA. They maintained high expression of tendon matrix associated genes, including COL1A1, COL1A2, COL3A1, ELN, FBLN1, and up-regulated genesets enriched for TNF-{gamma} signalling via NF{kappa}B, IFN-{gamma} signalling and IL-6/ STAT3 signalling. When cells were pre-selected based on surface protein markers, a similar up-regulation of pro-inflammatory signalling pathways was observed, particularly in PTX3 gene expressing CD10+CD26+CD54+ cells, with increased expression of genes associated with TNF- signalling and IFN-{gamma} signalling. Discrete human tendon cell sub populations persist in vitro culture and can be recognised by specific gene and surface protein signatures. Aligned PDO fibres promote the survival of three clusters, including pro-inflammatory PTX3 expressing CD10+CD26+CD54+ cells found in chronic tendon disease.

cell biology↗

bioRxiv2019

Identification of human tendon cell populations in healthy and diseased tissue using combined single cell transcriptomics and proteomics

The long-term morbidity of tendon disease in an increasingly active and ageing population represents a growing area of unmet clinical need. Tendon disorders commonly affect the lower limb, ranging from isolated tendon rupture to degenerative joint deformity. In the absence of valid animal models of chronic tendinopathy, traditional methods to isolate and identify crucial sub types involved in disease are limited by the heterogeneity of tendon cells, by their relative paucity in tissue and by the density of the surrounding collagen matrix. To overcome this, we have used next generation CITE-sequencing to combine surface proteomics with in-depth, unbiased gene expression analysis of single cells derived ex vivo from healthy and diseased tendon. For the first time we have been able to show that human tendon consists of at least eight sub-populations of cells. In addition to endothelial cells, Tc cells, and macrophages, there are five distinct tenocyte populations expressing COL1A genes. These consist of a population of resident cells expressing microfibril associated genes (FBN1, VCAN, DCN, EMILIN1, MFAP5), a group of SCX+ cells co-expressing high levels of pro-inflammatory markers, a population of APOD+ fibro-adipogenic progenitors (FAPs), TPPP3/PRG4+ chondrogenic cells (COMP, CILP, PRG4) and ITGA7+ Smooth Muscle-Mesenchymal Cells, recently described in mouse muscle but not, as yet, in human tendon. Surface proteomic analysis identified markers by which these sub-classes could be isolated and targeted in future. In comparison to healthy tendon, diseased tendon harboured a greater proportion of SCX+ tendon cells and these expressed high levels of pro-inflammatory markers including CXCL1, CXCL6, CXCL8, PDPN and previously undescribed PTX3. We were also able to show that whereas disease associated genes such as CD248 and PDPN were expressed by COL1+ tenocytes, IL33 was restricted to endothelial cells of chronically diseased tendon.

cell biology↗