The effects of long-term low selenium diet on the expression of CHST-3, CHST-12 and UST in knee cartilage of growing rats.
OBJECTIVES
To investigate the effect of low selenium diet on rat´s knee cartilage and expression of chondroitin sulfate (CS) sulfated enzymes in articular and epiphyseal-plate cartilage of rats' femur and tibia.


METHODS
Twenty-four SD rats were randomly divided into two groups with six female and six male in each group: control group (selenium 0.18 mg/kg), and low selenium group (selenium 0.02 mg/kg). After 109 days, the rats were sacrificed. The ultrastructural changes in chondrocytes of rat knee cartilage were observed by transmission electron microscopy (TEM). The morphology and pathology changes of knee cartilage were examined by hematoxylin-eosin (HE) and toluidine blue (TB) staining. The localization and expression of enzymes involved in CS sulfation, including chondroitin 6-O-sulfotransferase 1 (CHST-3), chondroitin 4-O-sulfotransferase 2 (CHST-12) and uronyl 2-O-sulfotransferase (UST) were examined by immunohistochemical staining and semi-quantitative analysis.


RESULTS
In low selenium group, ultrastructural changes of chondrocytes were observed in articular cartilage of femur (AF), articular cartilage of tibia (AT), epiphyseal-plate cartilage of femur (EF) and epiphyseal-plate cartilage of tibia (ET); however, no significant changes in chondrocytes number were observed in the above AF, AT, EF or ET. Moreover, reduced thickness of cartilage layer in AF, EF and ET was detected along with reduced staining areas of sulfated glycosaminoglycan in EF and ET in low selenium group. In addition, positive staining rate of CHST-3 was lower in AF, AT and EF, while positive staining rates of CHST-12 and UST were lower in AF, AT, EF and ET in low selenium group when compared with control group.


CONCLUSIONS
Low selenium undermines the ultrastructure of chondrocytes, inhibits the normal development of cartilage and the expression of CS sulfated enzymes.
['Wang|Liyun|L|', 'Guo|Xiong|X|', 'Yi|Jianhua|J|', 'Qu|Chengjuan|C|', 'Lei|Jian|J|', 'Guo|Qingquan|Q|', 'Han|Jing|J|']
D000818:Animals D002358:Cartilage, Articular D019902:Chondrocytes D005260:Female D007719:Knee Joint D008297:Male D046529:Microscopy, Electron, Transmission D051381:Rats D017207:Rats, Sprague-Dawley D012643:Selenium D015238:Sulfotransferases
Low selenium Knee cartilage Chondroitin sulfate Sulfation Sulfotransferases