Are There Any Differences in the Healing Capacity between the Medial Collateral Ligament’s (MCL) Proximal and Distal Parts in the Human Knee? Quantitative and Immunohistochemical Analysis of CD34, α-Smooth Muscle Actin (α-SMA), and Vascular Endothelial Growth Factor (VEGF) Expression Regarding the Epiligament (EL) Theory
Issued Date
2024-03-01
Resource Type
eISSN
22279059
Scopus ID
2-s2.0-85188708801
Journal Title
Biomedicines
Volume
12
Issue
3
Rights Holder(s)
SCOPUS
Bibliographic Citation
Biomedicines Vol.12 No.3 (2024)
Suggested Citation
Georgiev G.P., Yordanov Y., Gaydarski L., Tubbs R.S., Olewnik Ł., Zielinska N., Piagkou M., Ananiev J., Dimitrova I.N., Slavchev S.A., Terziev I., Suwannakhan A., Landzhov B. Are There Any Differences in the Healing Capacity between the Medial Collateral Ligament’s (MCL) Proximal and Distal Parts in the Human Knee? Quantitative and Immunohistochemical Analysis of CD34, α-Smooth Muscle Actin (α-SMA), and Vascular Endothelial Growth Factor (VEGF) Expression Regarding the Epiligament (EL) Theory. Biomedicines Vol.12 No.3 (2024). doi:10.3390/biomedicines12030659 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/97800
Title
Are There Any Differences in the Healing Capacity between the Medial Collateral Ligament’s (MCL) Proximal and Distal Parts in the Human Knee? Quantitative and Immunohistochemical Analysis of CD34, α-Smooth Muscle Actin (α-SMA), and Vascular Endothelial Growth Factor (VEGF) Expression Regarding the Epiligament (EL) Theory
Author's Affiliation
School of Medicine
University Hospital 'Queen Giovanna '
Medical University of Sofia
Tulane University School of Medicine
Mahidol University
University Hospital Alexandrovska
Trakia University Faculty of Medicine
Medical University of Lodz
St. George’s University
In Silico and Clinical Anatomy Research Group (iSCAN)
University Hospital 'Queen Giovanna '
Medical University of Sofia
Tulane University School of Medicine
Mahidol University
University Hospital Alexandrovska
Trakia University Faculty of Medicine
Medical University of Lodz
St. George’s University
In Silico and Clinical Anatomy Research Group (iSCAN)
Corresponding Author(s)
Other Contributor(s)
Abstract
The human knee is a complex joint that comprises several ligaments, including the medial collateral ligament (MCL). The MCL provides stability to the knee and helps prevent its excessive inward movement. The MCL also has a thin layer of connective tissue known as the epiligament (EL), which adheres to the ligament. This unique feature has drawn attention in the field of ligament healing research, as it may have implications for the recovery process of MCL injuries. According to the EL theory, ligament regeneration relies heavily on the provision of cells, blood vessels, and molecules. The present study sought to compare the expression of vascular endothelial growth factor (VEGF), CD34, and α-smooth muscle actin (α-SMA) in healthy knees’ proximal and distal MCL segments to better understand how these proteins affect ligament healing. By improving the EL theory, the current results could lead to more effective treatments for ligament injury. To conduct the present analysis, monoclonal antibodies were used against CD34, α-SMA, and VEGF to examine samples from 12 fresh knee joints’ midsubstance MCLs. We identified a higher cell density in the EL than in the ligament connective tissue, with higher cell counts in the distal than in the proximal EL part. CD34 immunostaining was weak or absent in blood vessels and the EL, while α-SMA immunostaining was strongest in smooth muscle cells and the EL superficial layer. VEGF expression was mainly in the blood vessels’ tunica media. The distal part showed more SMA-positive microscopy fields and higher cell density than the proximal part (4735 vs. 2680 cells/mm2). Our study identified CD34, α-SMA, and VEGF expression in the MCL EL, highlighting their critical role in ligament healing. Differences in α-SMA expression and cell numbers between the ligament’s proximal and distal parts may explain different healing capacities, supporting the validity of the EL theory in ligament recovery.