Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro

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 x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), 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 (M(r)155,000 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 addition 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.

Alterations of ATPase activity and erythrocyte oxygen consumption in patients with liver-blood deficiency syndrome

ＡｌｔｅｒａｔｉｏｎｓｏｆＡＴＰａｓｅａｃｔｉｖｉｔｙａｎｄｅｒｙｔｈｒｏｃｙｔｅｏｘｙｇｅｎｃｏｎｓｕｍｐｔｉｏｎｉｎｐａｔｉｅｎｔｓｗｉｔｈｌｉｖｅｒｂｌｏｏｄｄｅｆｉｃｉｅｎｃｙｓｙｎｄｒｏｍｅＳＨＩＬｉｎＪｉｅ１，ＬＩＵＪｕｎＦａｎ２...

Identification and analysis of mutations of the Wilson disease gene in Chinese population

OBJECTIVE: To investigate the characteristics of mutations in exon 3-20 of Wilson disease (WD) gene and their consequences in Chinese population. METHODS: Sixty unrelated normal Chinese and forty-four unrelated WD patients were studied. Genomic DNA was prepared from peripheral blood leukocytes by a salt-out method. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and subsequently direct sequencing were used to identify the mutations and polymorphisms of WD gene. RESULTS: Ten different mutations have been found, accounting for 52% of the mutant genes. Five of them are identified as novel missense mutations. Mutations Arg778Leu, Thr935Met and Ala874Val were represented respectively in 28.4%, 6.8% and 3.4% of WD chromosomes. The remaining mutations were found rare and limited to one or two patients. A total of 11 patients were homozygous for a single mutation, and 17 patients were in a compound heterozygous state with or without a known mutation. CONCLUSION: In Chinese, WD seems to result from two or three relatively common mutations and a large number of rare mutations. Arg778Leu and Thr935Met might be hotspots of mutation in Chinese population. The results indicated that the feature of mutations of WD gene is different between Chinese and the Western. Instead of exon 14 and exon 18, we had to select exon 8 and exon 12 first to detect mutations of WD gene in Chinese. It is of great importance to establish a direct diagnostic method for WD. This study improves our knowledge on functional domains of the WD gene, and helps elucidate the wide spectrum of manifestations of the disease as well.

Effects of Compound Shenhua Tablet(复方肾华片) on Renal Tubular Na^+-K^+-ATPase in Rats with Acute Ischemic Reperfusion Injury

Objective： To observe the effect of Compound Shenhua Tablet （复方肾华片, SHT） on the sodium- potassium-exchanging adenosinetriphosphatase （Na＋-K＋-ATPase） in the renal tubular epithelial cells of rats with acute ischemic reperfusion and to investigate the mechanisms underlying the effects of SHT on renal ischemic reperfusion injury （RIRI）. Methods： Fifty male Wistar rats were randomly divided into the sham surgery group, model group, astragaloside group [150 mg/（kg.d）], SHT low-dose group [1.5 g/（kg,d）] and SHT high-dose group [3.0 g/（kg.d）], with 10 rats in each group. After 1 week of continuous intragastric drug administration, surgery was performed to establish the model. At either 24 or 72 h after the surgery, 5 rats in each group were sacrificed, blood biochemistry, renal pathology, immunoblot and immunohistochemical examinations were performed, and double immunofluorescence staining was observed under a laser confocal microscope. Results： Compared with the sham surgery group, the serum creatinine （SCr） and blood urea nitrogen （BUN） levels were significantly increased, Na＋-K＋-ATPase protein level was decreased, and kidney injury molecule-1 （KIM-1） protein level was increased in the model group after the surgery （P〈0.01 or P〈0.05）. Compared with the model group, the SCr, BUN, pathological scores, Na＋-K＋-ATPase, and the KIM-1 protein level of the three treatment groups were significantly improved at 72 h after the surgery （P〈0.05 or P〈0.01）. And the SCr, BUN of the SHT low- and high-dose groups, and the pathological scores of the SHT high-dose group were significantly lower than those of the astragaloside group （P〈0.05）. The Iocalizations of Na＋-K＋-ATPase and megalin of the model group were disrupted, with the distribution areas overlapping with each other and alternately arranged. The severity of the disruption was slightly milder in three treatment groups compared with that of the model group. The results of immunofluorescence staining showed that the SHT high-dose group had a superior effect as compared with the astragaloside group and the SHT low-dose group. Conclusions： The SHT effectively alleviated RIRI caused by ischemic reperfusion, promoted the recovery of the polarity of renal tubular epithelial cells, and protected the renal tubules. The therapeutic effects of SHT were superior to those of astragaloside as a single agent.