Friday, December 18, 2009

Link N

The effect of Link N on differentiation of human bone marrow-derived mesenchymal stem cells.

"MSCs isolated from the bone marrow of three osteoarthritic patients{the gene expression of OA MSCs is different but it usually favors osteogenic rather than chondrogenic differentiation} were cultured in chondrogenic or osteogenic differentiation medium without or with Link N for 21 days.
Link N alone did not promote MSC chondrogenesis. However, after MSCs were supplemented with Link N in chondrogenic differentiation medium the quantity of GAG secreted into the culture medium, as well as aggrecan, COL2A1 and SOX9 gene expression, increased significantly. The gene expression of COL10A1 and osteocalcin (OC) were down-regulated significantly. When MSCs were cultured in osteogenic differentiation medium, Link N supplementation led to a significant decrease in mineral deposition, and alkaline phosphatase (ALP), OC and RUNX2 gene expression.
Link N can enhance chondrogenic differentiation and down-regulate hypertrophic and osteogenic differentiation of human MSCs."

"Link N (DHLSDNYTLDHDRAIH) is the N-terminal peptide of link protein, a glycoprotein that stabilizes the non-covalent interaction between an aggrecan G1 domain and hyaluronate"

Link N stimulates Col2a1 and decreases Col10a1 in normal human MSCs.

"MSCs were obtained from aspirates of the intramedullary canal of three osteoarthritic patients (40-60 years of age) undergoing total hip replacement"

"Since the DNA content of the cultures did not change significantly between days 3 and 21 of culture, the enhanced GAG synthesis is likely the result of increased production by each cell rather than a consequence of more cells due to cell proliferation"

"Link N alone does not directly stimulate chondrogenesis in a manner analogous to TGFβ, but rather enhances ongoing chondrogenesis"

"The ability of Link N to decrease the expression of ALP and OC may be through down-regulating the transcription regulator RUNX2"

The Effect of Link N on the Differentiation of Human Mesenchymal Stem Cells

"MSCs were isolated from the bone marrow of osteoarthritis (OA) patients. The cells were cultured in 24-well plates (3000 cells/well) in chondrogenesis differentiation medium (Invitrogen, Canada) according to the manufacturer's instructions. Link N was dissolved in the media with a final concentration of 0.1 µg/mL and 1 µg/mL, respectively. Medium without Link N was applied as a control. The media were changed every 3 days, and the used media were collected and stored at −20°C for GAG analysis. For gene expression analysis, the cells were cultured for 7, 14, and 21 days.
With the concentrations of 0.1 and 1.0 µg/mL, no toxic effect of Link N on MSCs was observed. After MSCs were cultured for 7 days and 14 days, the expression of aggrecan (ACAN), collagen II (COL2A1) and the transcription regulator SOX9 increased significantly in the media with 0.1 µg/mL or 1.0 µg/mL Link N. No significant differences were observed at day 21. When cells were cultured with 0.1 or 1.0 µg/mL Link N, the quantity of GAG in the media increased significantly at day 9, 12, and 15, but no major difference was observed at day 3 and 6 and at day 18 and 21. When MSCs were cultured for 7, 14, and 21 days, no significant effect of Link N on the expression of alkaline phosphatase (ALP) was observed. Link N significantly inhibited osteocalcin (OC) gene expression after culturing MSCs for 21 days."

We need to find some studies on Link N on normal human bone marrow.

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