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- Berglund, Maria, 1975-, et al.
(författare)
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Assessment of mRNA levels for matrix molecules and TGF-B1 in rabbit flexor and peroneus tendons reveals regional differences in steady-state expression
- 2004
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Ingår i: Journal of Hand Surgery - British and European Volume. - : SAGE Publications. - 0266-7681 .- 1532-2211. ; 29:2, s. 165-169
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Tidskriftsartikel (refereegranskat)abstract
- This study analysed the differences on a molecular level between two segments of the deep flexor tendon, and compared the intrasynovial flexor tendon with the tendon sheath and the extrasynovial peroneus tendon in a rabbit model. The TRIspin method of RNA extraction was combined with the reverse transcription polymerase chain reaction to assess mRNA levels in the tissue segments. Significant differences were detected for all genes studied. mRNA levels for aggrecan, biglycan and collagen III were significantly higher in the fibrocartilaginous proximal segment of the flexor tendon. Collagen I was higher in the flexor tendon than the sheath and the peroneus tendon, and TGF-beta1 was significantly lower in the peroneus tendon. This study demonstrates differences at the mRNA level between different segments of tendon, indicating that the tendon tissue may be adapted to its environment.
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| 2. |
- Berglund, Maria, 1975-, et al.
(författare)
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Growth Factor and Protease Expression during Different Phases of Healing after Rabbit Deep Flexor Tendon Repair
- 2011
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Ingår i: Journal of Orthopaedic Research. - : Wiley. - 0736-0266 .- 1554-527X. ; 29:6, s. 886-892
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the study was to contribute to the mapping of molecular events during flexor tendon healing, in particular the growth factors insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF) and nerve growth factor (NGF), matrix metalloproteinases (MMP-3 and MMP-13) and their inhibitors (tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-3, and the protease cathepsin K. In a rabbit model of flexor tendon injury, the mRNA expression for the growth factors, MMPs and TIMPs were measured in tendon and tendon sheath tissue at several time points (3, 6, 21, and 42 days) representing different phases of the healing process. We found that MMP-13 remained increased during the study period, whereas MMP-3 returned to normal levels within the first week after injury. TIMP-3 was down-regulated in the tendon sheaths. Cathepsin K was up-regulated in tendons and sheaths after injury. NGF was present in both tendons and sheaths, but unaltered. IGF-1 exhibited a late increase in the tendons, while VEGF was down-regulated at the later time points. In conclusion, we have demonstrated the presence of NGF in flexor tendons. MMP-13 expression appears to play a more protracted role in flexor tendon healing than MMP-3. The relatively low levels of endogenous IGF-1 and VEGF mRNA following injury support their potential beneficial role as exogenous modulators to optimize tendon healing and strength without increasing adhesion formation.
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| 3. |
- Berglund, Maria, 1975-, et al.
(författare)
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Patterns of mRNA expression for matrix molecules and growth factors in flexor tendon injury : differences in the regulation between tendon and tendon sheath
- 2006
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Ingår i: Journal of Hand Surgery-American Volume. - : Elsevier BV. - 0363-5023 .- 1531-6564. ; 31A:8, s. 1279-1287
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Injuries to tendons, particularly flexor tendons, can lead to loss of function after healing due to adhesion formation and other complications. The aim of this study was to increase our understanding of the healing process in tendons and tendon sheaths to develop methods to affect the healing process and improve the outcome of tendon repair in the future. METHODS: In a rabbit model of flexor tendon injury, tissues were harvested 3, 6, 12, and 24 days after surgery (n = 6 for each group). After RNA extraction, messenger RNA (mRNA) levels for relevant genes in tendon and tendon sheaths were measured using the reverse transcription polymerase chain reaction. Messenger RNA levels for a subset of relevant molecules at different time points after injury were compared with those of uninjured controls for tendons and tendon sheaths. RESULTS: Initially after injury, there was a shift in collagen expression with a marked increase in type III mRNA levels in both the tendon and tendon sheath, whereas those for collagen I increased only in the sheath at later time points. Aggrecan and versican mRNA levels were increased in both tissues, but temporal aspects of the changes were different. The mRNA levels for biglycan and lumican were all upregulated throughout the healing interval examined, whereas those for decorin were significantly decreased throughout in the tendon more so than the sheath. The mRNA levels for basic fibroblastic growth factor and transforming growth factor beta were elevated after injury in the tendon but not in the sheath. In contrast, mRNA levels for connective tissue growth factor were unaltered or decreased in both tissues throughout the interval assessed. CONCLUSIONS: Healing after injury to the rabbit flexor tendon and tendon sheath follow a reproducible pattern of gene expression; however, the pattern in the tendon is very different from that in the sheath. These findings indicate that interventions developed to improve healing of these tissues will have to address these differences, because they will likely affect the outcomes.
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