Evaluation of adult equine bone marrow- and adipose-derived progenitor cell chondrogenesis in hydrogel cultures.

This research study evaluates and compares the potential of bone marrow mesenchymal stem cells (BM-MSCs) and adipose-derived progenitor cells (ADPCs) in creating new cartilage tissue, investigating how different hydrogel environments and the presence or absence of Transforming Growth Factor Beta 1 (TGFbeta1) influence their performance.

Methods and Analysis

• The researchers used adult equine progenitor cells – a type of stem cell that can change into different cell types under specific conditions – as the source of their BM-MSCs and ADPCs.
• These cells were encapsulated or contained within two types of hydrogels – agarose or self-assembling peptide hydrogels – which provided a three-dimensional environment for the cells to grow and differentiate.
• The hydrogel cultures were then kept in conditions either with or without TGFbeta1, a protein that stimulates cell proliferation and differentiation, for three weeks.
• The researchers then measured the synthesis and accumulation of the extracellular matrix (ECM), a network of molecules including collagen, enzymes, and glycoproteins that provide structural and biochemical support to cells. They focused on components of cartilage, as working chondrogenesis (cartilage formation) is crucial for successful cartilage resurfacing strategies.

Findings

• The study found that the presence of TGFbeta1 led to significant increases in ECM synthesis and accumulation in both BM-MSC and ADPC cultures, with varying degrees of enhancement depending on the type of hydrogel used.
• According to chromatographic analysis, both the cell types synthesized aggrecan-like proteoglycans, a key component of the cartilage ECM, when seeded in a peptide hydrogel culture exposed to TGFbeta1, although BM-MSCs produce it in a larger quantity.
• Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated that type II collagen gene, an important part of cartilage tissue, was expressed in BM-MSCs but not in ADPC cultures under the influence of TGFbeta1.
• The histological examination revealed that under TGFbeta1 stimulation, BM-MSCs in peptide hydrogels developed a continuous ECM rich in proteoglycans and type II collagen while ADPCs did not.
• Based on these findings, the researchers concluded that BM-MSCs demonstrated superior abilities for chondrogenesis when compared to ADPCs under these experimental conditions.