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Blockade of hypoxia-induced CXCR4 with AMD3100 inhibits production of OA-associated catabolic mediators IL-1β and MMP-13.

Li P, Deng J, Wei X, Jayasuriya CT, Zhou J, Chen Q, Zhang J, Wei L, Wei F - Mol Med Rep (2016)

Bottom Line: Binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its receptor C-X-C chemokine receptor type 4 (CXCR4) results in receptor activation and the subsequent release of matrix metalloproteinases (MMPs) that contribute to osteoarthritis (OA) cartilage degradation.By contrast, such changes did not occur to an appreciable degree in cells that were pretreated with AMD3100.The results of the present study demonstrate that even under hypoxic conditions, where CXCR4 expression is significantly elevated in chondrocytes, AMD3100 effectively blocks this receptor and protects chondrocytes from OA‑induced catabolism, suggesting that the successful inhibition of CXCR4 may be an effective approach for OA treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, The Second Hospital of Shanxi Medical University, Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Taiyuan, Shanxi 030001, P.R. China.

ABSTRACT
Binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its receptor C-X-C chemokine receptor type 4 (CXCR4) results in receptor activation and the subsequent release of matrix metalloproteinases (MMPs) that contribute to osteoarthritis (OA) cartilage degradation. As hypoxia is a defining feature of the chondrocyte microenvironment, the present study investigated the possible mechanism through which SDF‑1 induces cartilage degradation under hypoxic conditions. To do this, OA chondrocyte cultures and patient tissue explants pretreated with the CXCR4 inhibitor, AMD3100 were incubated with SDF‑1. It was identified that hypoxic conditions significantly elevated the expression of CXCR4 in osteoarthritic chondrocytes relative to normoxic conditions. Furthermore, SDF‑1 elevated MMP‑13 mRNA levels and proteinase activity. It also elevated the mRNA and protein levels of runt‑related transcription factor 2, and induced the release of glycosaminoglycans and the inflammatory cytokine, interleukin‑1β. By contrast, such changes did not occur to an appreciable degree in cells that were pretreated with AMD3100. The results of the present study demonstrate that even under hypoxic conditions, where CXCR4 expression is significantly elevated in chondrocytes, AMD3100 effectively blocks this receptor and protects chondrocytes from OA‑induced catabolism, suggesting that the successful inhibition of CXCR4 may be an effective approach for OA treatment.

No MeSH data available.


Related in: MedlinePlus

SDF-1/CXCR4 increases Runx2 expression levels. (A) Western blot analysis of Runx2 and a bar graph of the relative difference in Runx2 protein expression levels. The band intensities obtained from the three individual western blots were quantified using Image J software and indicated that SDF-1 treatment of osteoarthritis chondrocytes markedly increased Runx2 protein expression, while pretreatment of these cells with AMD3100 significantly reduced this effect. (B) Reverse transcription-quantitative polymerase chain reaction analysis of Runx2 indicated that SDF-1 significantly increased the expression of Runx2 while pretreatment of cells with AMD3100 significantly reduced this effect. Data are presented as means + standard deviation. SDF-1, stromal cell-derived factor-1; CXCR4, C-X-C chemokine receptor type 4; Runx2, runt-related transcription factor 2.
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f4-mmr-14-02-1475: SDF-1/CXCR4 increases Runx2 expression levels. (A) Western blot analysis of Runx2 and a bar graph of the relative difference in Runx2 protein expression levels. The band intensities obtained from the three individual western blots were quantified using Image J software and indicated that SDF-1 treatment of osteoarthritis chondrocytes markedly increased Runx2 protein expression, while pretreatment of these cells with AMD3100 significantly reduced this effect. (B) Reverse transcription-quantitative polymerase chain reaction analysis of Runx2 indicated that SDF-1 significantly increased the expression of Runx2 while pretreatment of cells with AMD3100 significantly reduced this effect. Data are presented as means + standard deviation. SDF-1, stromal cell-derived factor-1; CXCR4, C-X-C chemokine receptor type 4; Runx2, runt-related transcription factor 2.

Mentions: Total RNA and cell lysates were collected following 48 h treatment with SDF-1 alone or SDF-1 plus AMD3100. Controls were cultured in the absence of SDF-and AMD3100. Runx2 mRNA and protein expression levels were determined by RT-qPCR and western blotting, respectively. The results indicated that SDF-1 increased Runx2 mRNA (P=0.003) and protein expression levels, while the upregulation of Runx2 induced by SDF-1 was partially inhibited by AMD3100 (P=0.04; Fig. 4A and B).


Blockade of hypoxia-induced CXCR4 with AMD3100 inhibits production of OA-associated catabolic mediators IL-1β and MMP-13.

Li P, Deng J, Wei X, Jayasuriya CT, Zhou J, Chen Q, Zhang J, Wei L, Wei F - Mol Med Rep (2016)

SDF-1/CXCR4 increases Runx2 expression levels. (A) Western blot analysis of Runx2 and a bar graph of the relative difference in Runx2 protein expression levels. The band intensities obtained from the three individual western blots were quantified using Image J software and indicated that SDF-1 treatment of osteoarthritis chondrocytes markedly increased Runx2 protein expression, while pretreatment of these cells with AMD3100 significantly reduced this effect. (B) Reverse transcription-quantitative polymerase chain reaction analysis of Runx2 indicated that SDF-1 significantly increased the expression of Runx2 while pretreatment of cells with AMD3100 significantly reduced this effect. Data are presented as means + standard deviation. SDF-1, stromal cell-derived factor-1; CXCR4, C-X-C chemokine receptor type 4; Runx2, runt-related transcription factor 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940083&req=5

f4-mmr-14-02-1475: SDF-1/CXCR4 increases Runx2 expression levels. (A) Western blot analysis of Runx2 and a bar graph of the relative difference in Runx2 protein expression levels. The band intensities obtained from the three individual western blots were quantified using Image J software and indicated that SDF-1 treatment of osteoarthritis chondrocytes markedly increased Runx2 protein expression, while pretreatment of these cells with AMD3100 significantly reduced this effect. (B) Reverse transcription-quantitative polymerase chain reaction analysis of Runx2 indicated that SDF-1 significantly increased the expression of Runx2 while pretreatment of cells with AMD3100 significantly reduced this effect. Data are presented as means + standard deviation. SDF-1, stromal cell-derived factor-1; CXCR4, C-X-C chemokine receptor type 4; Runx2, runt-related transcription factor 2.
Mentions: Total RNA and cell lysates were collected following 48 h treatment with SDF-1 alone or SDF-1 plus AMD3100. Controls were cultured in the absence of SDF-and AMD3100. Runx2 mRNA and protein expression levels were determined by RT-qPCR and western blotting, respectively. The results indicated that SDF-1 increased Runx2 mRNA (P=0.003) and protein expression levels, while the upregulation of Runx2 induced by SDF-1 was partially inhibited by AMD3100 (P=0.04; Fig. 4A and B).

Bottom Line: Binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its receptor C-X-C chemokine receptor type 4 (CXCR4) results in receptor activation and the subsequent release of matrix metalloproteinases (MMPs) that contribute to osteoarthritis (OA) cartilage degradation.By contrast, such changes did not occur to an appreciable degree in cells that were pretreated with AMD3100.The results of the present study demonstrate that even under hypoxic conditions, where CXCR4 expression is significantly elevated in chondrocytes, AMD3100 effectively blocks this receptor and protects chondrocytes from OA‑induced catabolism, suggesting that the successful inhibition of CXCR4 may be an effective approach for OA treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, The Second Hospital of Shanxi Medical University, Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Taiyuan, Shanxi 030001, P.R. China.

ABSTRACT
Binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its receptor C-X-C chemokine receptor type 4 (CXCR4) results in receptor activation and the subsequent release of matrix metalloproteinases (MMPs) that contribute to osteoarthritis (OA) cartilage degradation. As hypoxia is a defining feature of the chondrocyte microenvironment, the present study investigated the possible mechanism through which SDF‑1 induces cartilage degradation under hypoxic conditions. To do this, OA chondrocyte cultures and patient tissue explants pretreated with the CXCR4 inhibitor, AMD3100 were incubated with SDF‑1. It was identified that hypoxic conditions significantly elevated the expression of CXCR4 in osteoarthritic chondrocytes relative to normoxic conditions. Furthermore, SDF‑1 elevated MMP‑13 mRNA levels and proteinase activity. It also elevated the mRNA and protein levels of runt‑related transcription factor 2, and induced the release of glycosaminoglycans and the inflammatory cytokine, interleukin‑1β. By contrast, such changes did not occur to an appreciable degree in cells that were pretreated with AMD3100. The results of the present study demonstrate that even under hypoxic conditions, where CXCR4 expression is significantly elevated in chondrocytes, AMD3100 effectively blocks this receptor and protects chondrocytes from OA‑induced catabolism, suggesting that the successful inhibition of CXCR4 may be an effective approach for OA treatment.

No MeSH data available.


Related in: MedlinePlus