Involvement of cyclin-dependent kinase 5 in 2,5-hexanedione-induced neuropathy.
Occupational exposure to n-hexane produces a neuropathy characterized as a central-peripheral distal axonopathy, which is mediated by 2,5-hexanedione (HD). To investigate the mechanisms of the neuropathy induced by HD, the contents and activities of cyclin-dependent kinase 5 (CDK5) and activators (p35 precursor, p35 and p25) in rats' cerebrum cortex (CC), spinal cord (SC) and sciatic nerve (SN) were determined. The results showed that the levels and activities of CDK5 in CC of 200 or 400mg/kg HD-treated rats were significantly decreased in both the cytosolic and membrane fractions and negatively correlated with gait abnormality in the cytosolic fraction. However, CDK5 contents and activities in SN of rats treated with 200 or 400mg/kg HD were significantly increased and positively correlated with gait abnormality in both the cytosolic and membrane fractions. Although increases of CDK5 contents in both the cytosolic and membrane fractions of SC in 200 and 400mg/kg HD-treated rats were also observed, CDK5 activities were significantly decreased in the cytosolic fraction and negatively correlated with gait abnormality. The changes of p35 precursor, p35 and p25 contents in CC, SC and SN showed the same pattern with that of CDK5 activities. Thus, HD intoxication was associated with deregulation of CDK5 and its activator p35 or p25 in nerve tissues. The inconsistent changes of CDK5 activities in CNS and PNS might delegate the different mechanisms of HD-induced peripheral neuropathy.
Wang
Qing-Shan
QS
Institute of Toxicology, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
Zhang
Cui-Li
CL
Hou
Li-Yan
LY
Zhao
Xiu-Lan
XL
Yang
Xi-Wei
XW
Xie
Ke-Qin
KQ
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism*; D005684:Gait / Q000187:drug effects; D006588:Hexanones / Q000633:toxicity*; D008297:Male; D009498:Neurotoxins / Q000633:toxicity*; D010770:Phosphotransferases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000187:drug effects* / Q000378:metabolism; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism
C492235:Cdk5r1 protein, rat; D006588:Hexanones; D009498:Neurotoxins; C011269:2,5-hexanedione; D010770:Phosphotransferases; D051360:Cyclin-Dependent Kinase 5