Original Research
Copyright ©The Author(s) 2001. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 15, 2001; 7(6): 846-851
Published online Dec 15, 2001. doi: 10.3748/wjg.v7.i6.846
Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro
Guo-Qing Hou, Xiu-Ling Liang, Rong Chen, Lien Tang, Ying Wang, Ping-Yi Xu, Ying-Ru Zhang, Cui-Hua Ou
Guo-Qing Hou, Department of Neurology, Guangzhou First Municipal People’s Hospital, Guangzhou Medical College, Guangzhou 510180, Guangdong Province, China
Xiu-Ling Liang, Rong Chen, Ying Wang, Ping-Yi Xu, Ying-Ru Zhang, Cui-Hua Ou, Department of Neurology, First Affiliated Hospital, Sun Yat-Sen University of Medical Sciences, Guangzhou 510080, Guangdong Province, China
Lien Tang, Department of Pharmacology, University of Kentucky, Lexington, KY 40506, USA
Author contributions: All authors contributed equally to the work.
Supported by Key Clinical Program of Ministry of Ministry of Health (No.37091), “211 Project" of SUMS sponsored by Ministry of Health, and Guangdong Provincial Natural Science Foundation, No.990064
Correspondence to: Dr. Guo-qing Hou, Department of Neurology, Guangzhou First Municipal People’s Hospital, Guangzhou Medical College, 1 Panfu Rd, Guangzhou 510180, China. spring-hua@126.com
Telephone: +86-20-81083090 Ext 596, Fax: +86-20-81094250
Received: June 12, 2001
Revised: September 19, 2001
Accepted: September 28, 2001
Published online: December 15, 2001

AIM: To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD).

METHODS: WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls. These cultured hepatocytes were incubated in the media of copper 15 mg•L¯¹ only, copper 15 mg•L¯¹ with vincristine (agonist of P-type ATPase) 0.5 mg•L¯¹, or copper 15 mg•L¯¹ with vanadate (antagonist of P-type ATPase) 18.39 mg•L¯¹ separately. Microsome (endoplasmic reticulum and Golgiapparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls.

RESULTS: The specific WD proteins (Mr 155000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addtion of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P -type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase.

CONCLUSION: Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

Keywords: glucuronosyltranferase/genetics, glucurono syltranferase/biosynthesis, DNA, complementary/genetics, liver/cytology, hasters, lung/cytology, animal