Clones of Interstitial Cells From Bovine Aortic Valve Exhibit Different Calcifying Potential When Exposed to Endotoxin and Phosphate

Abstract

Objective-Our purpose was to study in vitro whether phenotypically-distinct interstitial cell clones from bovine aortic valve (BVIC) possess different calcifying potential in response to endotoxin (lipopolysaccharide [LPS]) and phosphate (Pi

Extracellular pyrophosphate is reduced in aortic interstitial valve cells acquiring a calcifying profile: Implications for aortic valve calcification

“…5B). Characteristics of the cells under investigation have been previously described [18]. In particular, both showed a cobble-stone morphology without forming nodules, although Clone 1 cells appear smaller and with a faster proliferation rate.…”

“…In particular, both showed a cobble-stone morphology without forming nodules, although Clone 1 cells appear smaller and with a faster proliferation rate. The two clones did not show significant differences in the immunophenotypic profile, except for a slight increase in smooth muscle alpha-actin expression in Clone 2 cells [18]. Of interest, when seeded on the bottom of transwell chambers for twelve days, both Clone 1 and Clone 2 showed a significant ability in reducing serum-driven calcification.…”

“…Primary VIC were obtained from aortic bovine valve leaflets by culture of tissue fragments digested with type-I collagenase, elastase, and soybean trypsin inhibitor (SigmaeAldrich) as previously described [18]. Cells obtained were expanded in DMEM containing 4.5 g/L glucose plus FBS 20%, 100 U/mL penicillin, and 100 mg/mL streptomycin (Sigma).…”

“…We previously isolated and characterized several clonal subpopulations of VIC carrying different calcifying potential [18,24]. We observed that only a specific subset of bovine aortic VIC harbors a strong calcifying potential when exposed to pro-inflammatory stimuli, such as endotoxin (LPS).…”

“…We observed that only a specific subset of bovine aortic VIC harbors a strong calcifying potential when exposed to pro-inflammatory stimuli, such as endotoxin (LPS). In fact, upon stimulation with LPS these pro-calcific clonal cells expressed high levels of ALP and strongly calcified a collagen matrix [18,24]. We sought to clarify whether the different VIC subtypes also carry different ability in protecting the matrix from serum-driven calcification.…”