Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Glucosamine ; pharmacology ; Humans ; Liver Neoplasms ; pathology ; Tumor Cells, Cultured

Recent epidemiological studies suggest that alcohol consumption is one of the risk factors leading to type 2 diabetes, but the direct effect of ethanol on beta-cell gene expression is not known. Here, using cDNA RDA method, we isolated 43 ethanol-induced genes in pancreatic beta-cells, and confirmed their differential expression by Northern blot or semi-quantitative RT-PCR. These genes were further categorized by the functional criteria based on the published data; Translation, Transcription, Metabolism, Signal transduction, Transport, Structure, Cytoskeleton, Regulation, or Putative/Unknown genes. The effects of each gene on beta-cell function need to be further investigated, however, the present data strongly suggest that these genes might be related to the metabolic alterations caused by ethanol as indicated in earlier study. In particular, RPS3 gene expression was increased by ethanol, glucosamine, and cytokines, implying that ethanol might decrease the metabolic activity by oxidative stress in beta-cells. Therefore, cloning of these genes in full-length and the detailed studies of each gene on beta-cell functions might provide clues on the pathophysiology of type 2 diabetes caused by alcohol.
Alcohol Drinking ; Animals ; Cytokines/pharmacology ; Ethanol/*pharmacology ; *Gene Expression Regulation ; Glucosamine/pharmacology ; Humans ; Islets of Langerhans/*drug effects/*physiology ; Oligonucleotide Array Sequence Analysis/methods ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction/methods

OBJECTIVES: To observe the effects of Yougui pill (Traditional Chinese Medicine) on the related factors of Wnt signal pathway of rats with knee osteoarthritis (KOA), and explore its protective mechanism. METHODS: Sixty SPF SD rats were randomly divided into the sham-operative group, model group, glucosamine sulfate group, high-dose, middle-dose, low-dose of Yougui pill treated group (=10). KOA model was established by modified Hulth method for six weeks. The rats in the high, middle and low-dose of Yougui pill group were treated with Yougui pills at the doses of 20,10 and 5 g/kg respectively by gastrogavage once a day for 8 weeks, while equal volume of normal saline was given to those in the sham and model control group and an equal volume of glucosamine sulfate (1.7 g/kg·d) was given to those in glucosamine sulfate group for 8 weeks. The knee joint was removed after the last dose of drug. The pathological changes of cartilaginous tissues were observed under a microscope. The mRNA levels of Dickkopf homolog 1(DKK1), Wnt induced secreted protein 1(WISP1), Wnt1, low density lipoprotein receptor related protein 5(LRP5) and beta -catenin in rats cartilaginous tissues were analyzed by using RT-PCR method, and the protein contents of DKK1, WISP1, Wnt1, LRP5 and beta-catenin in cartilaginous tissues were detected by Western blot. RESULTS: Compared with the sham group, the articular cartilage was severely damaged, the Mankin score was increased significantly (<0. 05), the mRNA and protein expression levels of DKK1 in cartilaginous tissue were markedly decreased(<0.05), while those of WISP, Wnt1, LRP5 and beta-catenin were increased significantly in model group(<0.05). Compared with model group, the articular cartilage lesions was light (<0.05), the Mankin Score was decreased significantly(<0.05), and the mRNA and protein levels of DKK1 in cartilaginous tissue were increased(<0.05), while those of WISP, Wnt1, LRP5 and beta-catenin were decreased in Yougui pill high-dose group and glucosamine sulfate group (<0.05). CONCLUSIONS Yougui pill has protective effects on the KOA by inhibiting the expressions of WISP, Wnt1, LRP5, beta-catenin and increasing the expression of DKK1 cytokine in the Wnt signaling pathway.
Animals ; CCN Intercellular Signaling Proteins ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Glucosamine ; pharmacology ; Intercellular Signaling Peptides and Proteins ; metabolism ; Osteoarthritis, Knee ; drug therapy ; Proto-Oncogene Proteins ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Wnt Signaling Pathway ; Wnt1 Protein ; metabolism ; beta Catenin ; metabolism

The purpose of study was to explore the possible functions of Bcl-xL in the glucosamine sulfate-induced apoptosis of chronic myeloid leukemia K562 cells. Light microscopy and Wright-Giemsa staining were used to investigate the morphologic evidences for apoptosis of K562 cells induced by glucosamine sulfate (GS); immunofluorescence was used to observe the translocation of cathepsin D and cytochrome C during the apoptosis; Western blot was performed to detect the expression of Bcl-xL, Bid, Bax in K562 cells treated by GS. The results showed that many vacuoles were observed in the cytoplasma of the K562 cells treated by GS; fluorescent signals of cathepsin D and cytochrome were fransformed from granules to disperse form by using immunofluorescence; the expression of Bcl-xL was found down-regulated in K562 cells treated by GS, but not in the cells pre-treated with pepstatin A; the significant changes were not detected in expression of Bax and Bid protein before or after apoptosis. It is concluded that Bcl-xL protein may mediate relationship between cathepsin D and mitochondia pathway, Cathepsin D may play an important role in the GS inducing apoptosis of K562 cells through downregulation of Bcl-xL expression.
Apoptosis ; drug effects ; physiology ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Blotting, Western ; Cathepsin D ; metabolism ; Cytochromes c ; metabolism ; Fluorescent Antibody Technique ; Glucosamine ; pharmacology ; Humans ; K562 Cells ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism ; physiology

Glucosamine, a naturally occurring amino monosaccharide, has been reported to play a role in the regulation of apoptosis more than half century. However the effect of glucosamine on tumor cells and the involved molecular mechanisms have not been thoroughly investigated. Glucosamine enters the hexosamine biosynthetic pathway (HBP) downstream of the rate-limiting step catalyzed by the GFAT (glutamine:fluctose-6-phosphate amidotransferase), providing UDP-GlcNAc substrates for O-linked beta-N-acetylglucosamine (O-GlcNAc) protein modification. Considering that O-GlcNAc modification of proteasome subunits inhibits its activity, we examined whether glucosamine induces growth inhibition via affecting proteasomal activity. In the present study, we found glucosamine inhibited proteasomal activity and the proliferation of ALVA41 prostate cancer cells. The inhibition of proteasomal activity results in the accumulation of ubiquitinated proteins, followed by induction of apoptosis. In addition, we demonstrated that glucosamine downregulated proteasome activator PA28gamma and overexpression of PA28gamma rescued the proteasomal activity and growth inhibition mediated by glucosamine. We further demonstrated that inhibition of O-GlcNAc abrogated PA28gamma suppression induced by glucosamine. These findings suggest that glucosamine may inhibit growth of ALVA41 cancer cells through downregulation of PA28gamma and inhibition of proteasomal activity via O-GlcNAc modification.
Acetylglucosamine/chemistry/metabolism ; Alloxan/pharmacology ; Apoptosis/*drug effects ; Autoantigens/genetics/*metabolism ; Cell Line, Tumor ; Cell Proliferation/*drug effects ; Gene Expression Regulation, Neoplastic ; Glucosamine/*pharmacology ; Humans ; Male ; Phosphorylation ; Prostatic Neoplasms/*enzymology ; Proteasome Endopeptidase Complex/*antagonists & inhibitors/genetics/metabolism ; RNA, Small Interfering/genetics ; Ubiquitinated Proteins/metabolism