Enhanced chondrocyte proliferation and mesenchymal stromal cells chondrogenesis in coculture pellets mediate improved cartilage formation

Abstract

In this study, we aimed at investigating the interactions between primary chondrocytes and mesenchymal stem/stromal cells (MSC) accounting for improved chondrogenesis in coculture systems. Expanded MSC from human bone marrow (BM-MSC) or adipose tissue (AT-MSC) were cultured in pellets alone (monoculture) or with primary human chondrocytes from articular (AC) or nasal (NC) cartilage (coculture). In order to determine the reached cell number and phenotype, selected pellets were generated by combining: (i) human BM-MSC with bovine AC, (ii) BM-MSC from HLA-A2+ with AC from HLA-A2- donors, or (iii) human green fluorescent protein transduced BM-MSC with AC. Human BM-MSC and AC were also cultured separately in transwells. Resulting tissues and/or isolated cells were assessed immunohistologically, biochemically, cytofluorimetrically, and by RT-PCR. Coculture of NC or AC (25%) with BM-MSC or AT-MSC (75%) in pellets resulted in up to 1.6-fold higher glycosaminoglycan content than what would be expected based on the relative percentages of the different cell types. This effect was not observed in the transwell model. BM-MSC decreased in number (about fivefold) over time and, if cocultured with chondrocytes, increased type II collagen and decreased type X collagen expression. Instead, AC increased in number (4.2-fold) if cocultured with BM-MSC and maintained a differentiated phenotype. Chondro-induction in MSC-chondrocyte coculture is a robust process mediated by two concomitant effects: MSC-induced chondrocyte proliferation and chondrocyte-enhanced MSC chondrogenesis. The identified interactions between progenitor and mature cell populations may lead to the efficient use of freshly harvested chondrocytes for ex vivo cartilage engineering or in situ cartilage repair.

Engineering osteochondral constructs through spatial regulation of endochondral ossification

“…It has been reported that chondrogenically primed MSCs release growth factors and cytokines such as TGF-β3, BMP-2, IGF-1 and FGF-2 [53] and such soluble factors may play a role in enhancing chondrogenesis of chondrocytes co-cultured with MSCs [54][55]. Co-culture of chondrocytes and MSCs has also been shown to enhance proliferation of chondrocytes [54,56], although such a phenomena was not observed in our bi-layered co-culture system. Direct cell to cell interaction may be required to drive the enhanced proliferation of chondrocytes when cocultured with MSCs [56], which is absent in our culture model as cells are separately encapsulated in the different regions of the hydrogel.…”

“…Co-culture of chondrocytes and MSCs has also been shown to enhance proliferation of chondrocytes [54,56], although such a phenomena was not observed in our bi-layered co-culture system. Direct cell to cell interaction may be required to drive the enhanced proliferation of chondrocytes when cocultured with MSCs [56], which is absent in our culture model as cells are separately encapsulated in the different regions of the hydrogel.…”

Cell-Derived Polymer/Extracellular Matrix Composite Scaffolds for Cartilage Regeneration, Part 1: Investigation of Cocultures and Seeding Densities for Improved Extracellular Matrix Deposition

“…Previous efforts to investigate the utilization of cocultures containing chondrocytes and MSCs have primarily focused on studying the differentiation state of either cell type as opposed to focusing on the development of cartilage-like ECM within a scaffold. [45][46][47] The purpose of this study was to investigate and optimize the use of different coculture ratios of chondrocytes and MSCs in an effort to produce PCL/ECM constructs containing cartilage-like ECM, while reducing the total number of chondrocytes necessary to do so. Further, the influence of seeding density was also examined as it was hypothesized that a higher cell 35K'') or 70,000 cells/scaffold (''70K'') cultured for 7, 14, and 21 days.…”

Enhanced Chondrogenesis by Three-dimensional Co-culture of Chondrocytes and Mesenchymal Stem Cells

“…2). 연골세포와 줄기세포의 co-culture를 진행하면 줄기세포 의 사이토카인 (cytokine) 생성을 통해 연골세포의 증식을 자 극하는 것으로 알려져 있다 [12]. 또한, 3차원 배양에서 줄기 세포와 co-culture를 통해 구형의 sphere 형성으로 세포의 접 촉을 증가시켜 anoikis mechanism이 유도되지 않고 세포 사 멸을 억제하여 증식률을 높일 수 있다.…”