Alginate Encapsulation Impacts the Insulin-like Growth Factor-I System of Monolayer-Expanded Equine Articular Chondrocytes and Cell Response to Interleukin-1β
| Autor: | Rick D. Howard, Kimberly Forsten-Williams, R. Michael Akers, Ryan M. Porter |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Cartilage
Articular Alginates medicine.medical_treatment Interleukin-1beta Cell Culture Techniques Biocompatible Materials Insulin-like growth factor Chondrocytes Glucuronic Acid Alginate encapsulation Monolayer medicine Animals Horses Insulin-Like Growth Factor I Cells Cultured Cell Proliferation Dose-Response Relationship Drug Tissue Engineering Chemistry Hexuronic Acids fungi General Engineering Phenotype Cell biology body regions Immunology Female Cell response Alginate hydrogel |
| Zdroj: | Tissue Engineering. 13:1333-1345 |
| ISSN: | 1557-8690 1076-3279 |
| DOI: | 10.1089/ten.2006.0345 |
| Popis: | Alginate hydrogel culture has been shown to reestablish chondrocytic phenotype following monolayer expansion; however, previous studies have not adequately addressed how culture conditions affect the signaling systems responsible for chondrocyte metabolic activity. Here we investigate whether chondrocyte culture history influences the insulin-like growth factor-I (IGF-I) signaling system and its regulation by interleukin-1 (IL-1). Articular chondrocytes (ACs) from equine stifle joints were expanded by serial passage and were either encapsulated in alginate beads or maintained in monolayer culture for 10 days. Alginate-derived cells (ADCs) and monolayer-derived cells (MDCs) were then plated at high density, stimulated with IL-1beta (1 and 10 ng/mL) or IGF-I (50 ng/mL) for 48 h, and assayed for levels of type I IGF receptor (IGF-IR), IGF binding proteins (IGFBPs), and endogenously secreted IGF-I. Intermediate alginate culture yielded relatively low IGF-IR levels that increased in response to IL-1beta, whereas higher receptor levels on MDCs were reduced by cytokine. MDCs also secreted substantially more IGFBP-2, the predominant binding protein in conditioned media (CM), though IL-1beta suppressed levels for both cell populations. Concentrations of autocrine/paracrine IGF-I paralleled IGFBP-2 secretion. Disparate basal levels of IGF-IR and IGFBP-2, but not IGF-I, were attributed to relative transcript expression. Systemic differences coincided with varied effects of IL-1beta and IGF-I on cell growth and type I collagen expression. We conclude that culture strategy impacts the IGF-I signaling system of ACs, potentially altering their capacity to mediate cartilage repair. Consideration of hormonal regulators may be an essential element to improve chondrocyte culture protocols used in tissue engineering applications. |
| Databáze: | OpenAIRE |
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