Effect of acetaminophen and nonsteroidal anti-inflammatory drugs on gene expression of mesenchymal stem cells.

We have previously shown that mesenchymal stem cells (MSCs) from patients with osteoarthritis (OA) constitutively express type X collagen, a marker of late-stage chondrocyte hypertrophy, osteogenic marker genes, including alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC), and chondrogenesis marker gene aggrecan (ACAN). As patients with arthritis often take nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (Acet), the purpose of the study was to assess whether these drugs can affect the gene expression of human MSCs. MSCs isolated from the bone marrow of patients with OA or normal donors were cultured without (control) or with Acet or NSAIDs, which include ibuprofen, diclofenac (Dic), naproxen, and celebrex. After 3 days of culture, the expression of type X collagen alpha 1 (COL10A1), ACAN, COL1A1, as well as ALP, BSP, OC, and Runt-related transcription factor 2 was analyzed by real-time reverse transcription (RT)-polymerase chain reaction. The results showed that COL10A1 and the osteogenic and chondrogenic marker genes can be regulated by NSAIDs and Acet in normal MSCs. In contrast, Acet did not significantly affect COL10A1 expression in OA MSCs, while Dic is the only drug that had no significant effect on all markers in normal MSCs. The upregulation of COL10A1 in normal MCSs by Acet and Npx may explain why stem cells from patients with OA express COL10A1 constitutively. This knowledge may help in designing better strategies for stem cell differentiation into chondrocyte-like cells, from this source, with Dic being a viable option for treating OA pain, with an eye toward preventing the potential to enhance calcification in the repair of cartilage and degenerated intervertebral discs.

Stem cells, nitrogen-rich plasma-polymerized culture surfaces, and type X collagen suppression.

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into chondrocytes, osteoblasts, myocytes, adipocytes, and a variety of other cell types. Several studies have been directed toward using MSCs from patients with osteoarthritis (OA) for cartilage repair, not only because these are the ones that will require a source of autologous stem cells if biological repair of cartilage lesions is to be a therapeutic option, but also to further an understanding of stem cell differentiation. Previous studies have shown that a major drawback of current cartilage and intervertebral disc tissue repair is that human MSCs from OA patients express type X collagen (COL X). COL X, a marker of late-stage chondrocyte hypertrophy, is implicated in endochondral ossification. However, those studies also revealed that a novel plasma-polymerized thin film material, named nitrogen-rich plasma-polymerized ethylene (PPE:N), was able to inhibit COL X expression in committed MSCs. The specific aim of this present study was to determine if the suppression of COL X by PPE:N is maintained when MSCs are transferred to pellet cultures in serum-free media. Our results confirmed the potential of two different types of PPE:N surfaces (low-pressure-PPE:N [L-PPE:N] and high-pressure-PPE:N [H-PPE:N]) in suppressing COL X expression, more so on the latter. Interestingly, when MSCs were transferred to pellet cultures, the expression level of COL X was further decreased by preincubation on H-PPE:N, suggesting that these kinds of coatings show promise for tissue engineering of cartilage and disc tissues. Further studies are needed to assess the relative importance of surface-chemistry versus surface-morphology in the mechanism of COL X suppression.