Alterations in growth plate and articular cartilage morphology are associated with reduced SOX9 localization in the magnesium-deficient rat.
Insufficient dietary magnesium (Mg) intake has been associated with low bone mass in humans,and recent basic science studies have indicated that this bone loss may be secondary to increased release of substance P and TNFc Much less is known about the effects of low Mg intake on cartilage. We have evaluated growth plate and articular cartilage in rats following a 6 month dietary Mg restriction. Histomorphometry demonstrated significantly decreased distal femur articular cartilage chondrocyte density and decreased tibial growth plate width in experimental animals compared to controls. Growth plates of Mg-restricted animals showed reduced chondrocyte column formation. Extracellular matrix of both articular cartilage and growth plates in experimental animals contained reduced amounts of proteoglycans. Immunolocalization of Sox9 was decreased in both articular and growth plate cartilage in experimental animals compared to controls, suggesting that reduced Mg intake causes cartilage changes that may be secondary to reduced levels of the SOX9 transcription factor.
Gruber
H E
HE
Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina 28232, USA. hgruber@carolinas.org.
Ingram
J
J
Norton
H J
HJ
Wei
L Y
LY
Frausto
A
A
Mills
B G
BG
Rude
R K
RK
D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D006132:Growth Plate / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D008275:Magnesium Deficiency / Q000378:metabolism* / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055758:SOX9 Transcription Factor; D014157:Transcription Factors / Q000378:metabolism*
D006609:High Mobility Group Proteins; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; D014157:Transcription Factors