improvement-closed-chest-porcine-myocardial-infarction-model

Improvement of a Closed Chest Porcine Myocardial Infarction Model by Standardization of Tissue and Blood Sampling Procedures

Myocardial ischemia reperfusion (I/R) injury contributes to almost half of the necrotic area after myocardial infarction. To date there is no approved ...

University of Bern

Many studies in the field of cell-based cartilage repair have focused on identifying markers associated with the differentiation status of human articular chondrocytes (HAC) that could predict their chondrogenic potency. A previous study from our group showed a correlation between the expression of S100 protein in HAC and their chondrogenic potential. The aims of the current study were to clarify which S100 proteins are associated with HAC differentiation status and to provide an S100-based assay for measuring HAC chondrogenic potential. The expression patterns of S100A1 and S100B were investigated in cartilage and in HAC cultured under conditions promoting dedifferentiation (monolayer culture) or redifferentiation (pellet culture or BMP4 treatment in monolayer culture), using characterized antibodies specifically recognizing S100A1 and S100B, by immunohistochemistry, immunocytochemistry, Western blot, and gene expression analysis. S100A1 and S100B were expressed homogeneously in all cartilage zones, and decreased during dedifferentiation. S100A1, but not S100B, was re-expressed in pellets and co-localized with collagen II. Gene expression analysis revealed concomitant modulation of S100A1, S100B, collagen type II, and aggrecan: down-regulation during monolayer culture and up-regulation upon BMP4 treatment. These results strongly support an association of S100A1, and to a lesser extent S100B, with the HAC differentiated phenotype. To facilitate their potential application, we established an S100A1/B-based flow cytometry assay for accurate assessment of HAC differentiation status. We propose S100A1 and S100B expression as a marker to develop potency assays for cartilage regeneration cell therapies, and as a redifferentiation readout in monolayer cultures aiming to investigate stimuli for chondrogenic induction.

S100A1 and S100B expression patterns identify differentiation status of human articular chondrocytes.

Cytokines play an important role in cell signaling in inflammatory and repair processes, also within the posterior segment of the eye. These molecules are thus implicated in the pathophysiology of several vitreoretinal diseases. In the present study, we compared vitreal cytokine profiles in patients with idiopathic epiretinal membranes (ERMs) and idiopathic full-thickness macular holes (MHs) without epiretinal membranes.

Article	Year
S100A1 and S100B expression patterns identify differentiation status of human articular chondrocytes. Journal of cellular physiology\| PubMed ID: 24402969	2014
Vitreal Cytokine Profile Differences Between Eyes With Epiretinal Membranes or Macular Holes. Investigative ophthalmology & visual science\| PubMed ID: 27893098	2016

Alain Despont

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