Experimental study of millimeter wave-induced differentiation of bone marrow mesenchymal stem cells into chondrocytes.
Low power millimeter wave irradiation is widely used in clinical medicine. We describe the effects of this treatment on cultured mesenchymal stem cells (MSCs) and attempted to identify the underlying mechanism. Cells cultured using the whole marrow attachment culture method proliferated dispersedly or in clones. Flow cytometric analyses showed that the MSCs were CD90 positive, but negative for CD45. The negative control group (A) did not express detectable levels of Cbfa1 or Sox9 mRNA at any time point, while cells in the millimeter wave-induced groups (B and C) increasingly expressed both genes after the fourth day post-induction. Statistical analysis showed that starting on the fourth day post-induction, there were very significant differences in the expression of Cbfa1 and Sox9 mRNA between groups A and B as well as A and C at any given time point, between treated groups B and C after identical periods of induction, and within each treated group at different induction times. Transition electron microscopy analysis showed that the rough endoplasmic reticulum of cells in the induced groups was richer and more developed than in cells of the negative control group, and that the shape of cells shifted from long-spindle to near ellipse. Toluidine blue staining revealed heterochromia in the cytoplasm and extracellular matrix of cells in the induced groups, whereas no obvious heterochromia was observed in negative control cells. Induced cells also exhibited positive immunohistochemical staining of collagen II, in contrast to the negative controls. These results show that millimeter wave treatment successfully induced MSCs to differentiate as chondrocytes and the extent of differentiation increased with treatment duration. Our findings suggest that millimeter wave irradiation can be employed as a novel non-drug inducing method for the differentiation of MSCs into chondrocytes.
Wu
Guang-Wen
GW
1 Huatuo, University Town, Minhou Shangjie, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, PR China.
Liu
Xian-Xiang
XX
Wu
Ming-Xia
MX
Zhao
Jin-Yan
JY
Chen
Wen-Lie
WL
Lin
Ru-Hui
RH
Lin
Jiu-Mao
JM
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D002454:Cell Differentiation / Q000528:radiation effects*; D049109:Cell Proliferation / Q000528:radiation effects; D048430:Cell Shape / Q000528:radiation effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D024043:Collagen Type II / Q000032:analysis; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D018870:Endoplasmic Reticulum, Rough / Q000528:radiation effects / Q000648:ultrastructure; D005434:Flow Cytometry; D015870:Gene Expression / Q000528:radiation effects; D007150:Immunohistochemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055758:SOX9 Transcription Factor / Q000235:genetics; D018800:Thy-1 Antigens / Q000032:analysis; D013997:Time Factors
D024043:Collagen Type II; D050659:Core Binding Factor Alpha 1 Subunit; D012333:RNA, Messenger; D055758:SOX9 Transcription Factor; D018800:Thy-1 Antigens