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The association between retraction of the torn rotator cuff and increasing expression of hypoxia inducible factor 1α and vascular endothelial growth factor expression: an immunohistological study.

Lakemeier S, Reichelt JJ, Patzer T, Fuchs-Winkelmann S, Paletta JR, Schofer MD - BMC Musculoskelet Disord (2010)

Bottom Line: Differing levels of tendon retraction are found in full-thickness rotator cuff tears.HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p < 0.05).A correlation between HIF/VEGF expression and FI and MA could be found (p < 0.05).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany. lakemeie@med.uni-marburg.de

ABSTRACT

Background: Differing levels of tendon retraction are found in full-thickness rotator cuff tears. The pathophysiology of tendon degeneration and retraction is unclear. Neoangiogenesis in tendon parenchyma indicates degeneration. Hypoxia inducible factor 1α (HIF) and vascular endothelial growth factor (VEGF) are important inducers of neoangiogenesis. Rotator cuff tendons rupture leads to fatty muscle infiltration (FI) and muscle atrophy (MA). The aim of this study is to clarify the relationship between HIF and VEGF expression, neoangiogenesis, FI, and MA in tendon retraction found in full-thickness rotator cuff tears.

Methods: Rotator cuff tendon samples of 33 patients with full-thickness medium-sized rotator cuff tears were harvested during reconstructive surgery. The samples were dehydrated and paraffin embedded. For immunohistological determination of VEGF and HIF expression, sample slices were strained with VEGF and HIF antibody dilution. Vessel density and vessel size were determined after Masson-Goldner staining of sample slices. The extent of tendon retraction was determined intraoperatively according to Patte's classification. Patients were assigned to 4 categories based upon Patte tendon retraction grade, including one control group. FI and MA were measured on standardized preoperative shoulder MRI.

Results: HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p < 0.05). HIF and VEGF expression, and vessel density significantly increased with extent of tendon retraction (p < 0.05). A correlation between HIF/VEGF expression and FI and MA could be found (p < 0.05). There was no significant correlation between HIF/VEGF expression and neovascularity (p > 0.05)

Conclusion: Tendon retraction in full-thickness medium-sized rotator cuff tears is characterized by neovascularity, increased VEGF/HIF expression, FI, and MA. VEGF expression and neovascularity may be effective monitoring tools to assess tendon degeneration.

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Rotator cuff slices after straining with VEGF antibody (40× magnification). In the control group, VEGF expression is minimally observed (a); VEGF expression is high in group IV (b).
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Figure 1: Rotator cuff slices after straining with VEGF antibody (40× magnification). In the control group, VEGF expression is minimally observed (a); VEGF expression is high in group IV (b).

Mentions: Histomorphometrical analysis was performed at a primary objective lens magnification of 5× using a Leica DM5000 and Quips analysis software (Leica Bensheim, Germany). In order to characterize the cells and to perform cell count, 40× objective lens magnification was used. For differential stained slices, for example Masson Goldner stained slices, a 10× objective lens magnification was used. Vessel number and size was determined by counting and measuring the vessels in three different areas of every specimen. Cell counting of immunohistological stained slices was performed by a 40× objective lens magnification. The percentage stands for the quotient of VEGF and HIF positive cells in relation to the total number of cells per slice. The percentage stands for the quotient of HIF or VEGF positive cells in relation to the total number of cells per slice. Figures 1, 2 and 3 show examples for different tendon sections and stainings.


The association between retraction of the torn rotator cuff and increasing expression of hypoxia inducible factor 1α and vascular endothelial growth factor expression: an immunohistological study.

Lakemeier S, Reichelt JJ, Patzer T, Fuchs-Winkelmann S, Paletta JR, Schofer MD - BMC Musculoskelet Disord (2010)

Rotator cuff slices after straining with VEGF antibody (40× magnification). In the control group, VEGF expression is minimally observed (a); VEGF expression is high in group IV (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2958987&req=5

Figure 1: Rotator cuff slices after straining with VEGF antibody (40× magnification). In the control group, VEGF expression is minimally observed (a); VEGF expression is high in group IV (b).
Mentions: Histomorphometrical analysis was performed at a primary objective lens magnification of 5× using a Leica DM5000 and Quips analysis software (Leica Bensheim, Germany). In order to characterize the cells and to perform cell count, 40× objective lens magnification was used. For differential stained slices, for example Masson Goldner stained slices, a 10× objective lens magnification was used. Vessel number and size was determined by counting and measuring the vessels in three different areas of every specimen. Cell counting of immunohistological stained slices was performed by a 40× objective lens magnification. The percentage stands for the quotient of VEGF and HIF positive cells in relation to the total number of cells per slice. The percentage stands for the quotient of HIF or VEGF positive cells in relation to the total number of cells per slice. Figures 1, 2 and 3 show examples for different tendon sections and stainings.

Bottom Line: Differing levels of tendon retraction are found in full-thickness rotator cuff tears.HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p < 0.05).A correlation between HIF/VEGF expression and FI and MA could be found (p < 0.05).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany. lakemeie@med.uni-marburg.de

ABSTRACT

Background: Differing levels of tendon retraction are found in full-thickness rotator cuff tears. The pathophysiology of tendon degeneration and retraction is unclear. Neoangiogenesis in tendon parenchyma indicates degeneration. Hypoxia inducible factor 1α (HIF) and vascular endothelial growth factor (VEGF) are important inducers of neoangiogenesis. Rotator cuff tendons rupture leads to fatty muscle infiltration (FI) and muscle atrophy (MA). The aim of this study is to clarify the relationship between HIF and VEGF expression, neoangiogenesis, FI, and MA in tendon retraction found in full-thickness rotator cuff tears.

Methods: Rotator cuff tendon samples of 33 patients with full-thickness medium-sized rotator cuff tears were harvested during reconstructive surgery. The samples were dehydrated and paraffin embedded. For immunohistological determination of VEGF and HIF expression, sample slices were strained with VEGF and HIF antibody dilution. Vessel density and vessel size were determined after Masson-Goldner staining of sample slices. The extent of tendon retraction was determined intraoperatively according to Patte's classification. Patients were assigned to 4 categories based upon Patte tendon retraction grade, including one control group. FI and MA were measured on standardized preoperative shoulder MRI.

Results: HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p < 0.05). HIF and VEGF expression, and vessel density significantly increased with extent of tendon retraction (p < 0.05). A correlation between HIF/VEGF expression and FI and MA could be found (p < 0.05). There was no significant correlation between HIF/VEGF expression and neovascularity (p > 0.05)

Conclusion: Tendon retraction in full-thickness medium-sized rotator cuff tears is characterized by neovascularity, increased VEGF/HIF expression, FI, and MA. VEGF expression and neovascularity may be effective monitoring tools to assess tendon degeneration.

Show MeSH
Related in: MedlinePlus