OBJECTIVE: To investigate the significance of low-density lipoprotein receptor-related protein 5 and 6 (LRP5/6) in the Wnt/β-catenin signaling pathway in the pathogenesis and prognosis of childhood acute lymphoblastic leukemia (ALL). METHODS: A total of 43 children who were newly diagnosed and achieved complete remission after remission induction therapy were enrolled. The children before treatment were included in incipient group, and after treatment when achieved complete remission included in remission group. A total of 39 children with immune thrombocytopenia were enrolled in control group. Three milliliter bone marrow samples were collected from above-mentioned each group. QRT-PCR was used to determine the mRNA expression of LRP5 and LRP6 in blood mononuclear cells of bone marrow. Western blot was used to detect the protein expression of LRP5 and LRP6. According to the protein expression levels of LRP5 and LRP6, the children were divided into low-expression group and high-expression group, and the clinical biological characteristics were compared between these two groups. Survival analysis was performed by Kaplan-Meier method. RESULTS: Both mRNA and protein expression levels of LRP5 and 6 were upregulated in the incipient group compared with the control and remission group (P<0.05). The mRNA and protein expressions of LRP5 and LRP6 in the high-risk group were higher than those in the medium-risk group (P<0.05), it is the same as in the medium-risk group than the low-risk group (P<0.05). The mRNA and protein expressions of LRP5 and 6 positively correlated with risk degree in the incipient group (r CONCLUSION The high expression of LRP5/6 may be one of the pathogenesis of childhood ALL, and the degree of LRP5/6 increase may be related to the risk level.
Child ; Humans ; Lipoproteins, LDL ; Low Density Lipoprotein Receptor-Related Protein-5 ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Receptors, LDL ; Wnt Signaling Pathway ; beta Catenin/metabolism*

To study the effects of alkaloids from Coptidis Rhizoma on low-density lipoprotein receptor (LDLR) mRNA expression and antihyperlipedemic levels. The LDLR mRNA expression were detected by real time fluorescence quantitative PCR, and the levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-c) and high-density lipoprotein cholesterol (HDL-c) in serum were measured at the first and last examination. The results show that, after the drug treatment, compared with the model group, each drug group showed a lipid-lowering effect. Especially, coptisine, palmatine, jatrorrhinze were significantly reduced TC, TG, LDL-c (P < 0.05, P < 0.01), and increased HDL-c (P < 0.01). In addition, they also increased mRNA expression of the LDLR in liver and HepG2 cells. The results showed that alkaloids from Coptidis Rhizoma can regulate lipid metabolism disorder, and coptisine have the best lipid-lowering effect.
Alkaloids ; administration & dosage ; Animals ; Cholesterol ; metabolism ; Cricetinae ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Hyperlipidemias ; drug therapy ; genetics ; metabolism ; Hypoglycemic Agents ; administration & dosage ; Lipid Metabolism ; drug effects ; Lipids ; blood ; Lipoproteins, LDL ; metabolism ; Mesocricetus ; Receptors, Lipoprotein ; genetics ; metabolism ; Triglycerides ; metabolism

Both hydropathy plot and in vitro translation results predict the topology of SR-BI; the receptor is an integral membrane protein of 509 amino acids, consisting of a short cytoplasmic N-terminus of 9 amino acids followed by a first transmembrane domain of 22 amino acids, the extracellular domain of 408 amino acids, the second transmembrane domain of 22 amino acids, and the cytoplasmic C-terminus of 47 amino acids. The immunoblot of rBBMV in the presence or absence of pAb589 peptide antigen (the C-terminal 22 amino acid residues of SR-BI) confirmed that the bands at apparent molecular weight of 140 and 210 kDa are SR-BI related protein which might be multimeric forms of SR-BI. 125I apo A-I overlay analysis showed that SR-BI can bind to its ligand, apo A-I, only when it is thoroughly matured - glycosylated and dimerized. The antibody which was generated against extracellular domain of SR-BI (pAb230) not only prevented 125I-labeled apo A-I from binding to 140 kDa band but also inhibited the esterified cholesterol uptake of rabbit BBMV with its IC50 value of 40 microgram/ml of IgG. In contrast, the antibody generated against the C-terminal domain of SR-BI (pAb589) did not show any effect either on cholesterol uptake of rabbit BBMV or 125I-labeled apo A-I binding to 140 kDa band. Overall results show that the ligand binding site of SR-BI in rabbit BBMV is located in extracellular domain, and SR-BI is only functional when it is part of dimeric forms which rationalize the previously found cooperative nature of the binding interaction and maybe a fundamental finding towards the so far poorly understood mechanism of SR-BI function.
Amino Acid Sequence ; Animals ; Antigens, CD36/*metabolism ; Apolipoprotein A-I/metabolism ; Binding Sites/physiology ; Blotting, Western ; Caco-2 Cells ; Cholesterol Esters/metabolism ; Humans ; Intestinal Mucosa/metabolism ; Intestine, Small/*metabolism/ultrastructure ; Iodine Radioisotopes ; Membrane Proteins/*metabolism ; Microvilli/metabolism ; Molecular Sequence Data ; Rabbits ; *Receptors, Immunologic ; Receptors, Lipoprotein/*metabolism ; Receptors, Scavenger ; Scavenger Receptors, Class B ; Surface Properties

OBJECTIVETo develop a new high-throughput screening model for human high-density lipoprotein (HDL) receptor (CD36 and LIMPII analogous-1, CLA-1) agonists using CLA-1-expressing insect cells.

METHODSWith the total RNA of human hepatoma cells BEL-7402 as template, the complementary DNA (cDNA) of CLA-1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR). Bac-to-Bac baculovirus expression system was used to express CLA-1 in insect cells. CLA-1 cDNA was cloned downstream of polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV) into donor vector pFastBac1 and recombinant pFastBac1-CLA-1 was transformed into E. coli DH10Bac to transpose CLA-1 cDNA to bacmid DNA. Recombinant bacmid-CLA-1 was transfected into Spodoptera frugiperda Sf9 insect cells to produce recombinant baculovirus particles. Recombinant CLA-1 was expressed on the membrane of Sf9 cells infected with the recombinant baculoviruses. A series of parameters of DiI-lipoprotein binding assays of CLA-1-expressing Sf9 cells in 96-well plates were optimized.

RESULTSWestern blot analysis and DiI-lipoprotein binding assays confirmed that CLA-1 expressed in insect cells had similar immunoreactivity and ligand binding activity as its native counterpart. A reliable and sensitive in vitro cell-based assay was established to assess the activity of CLA-1 and used to screen agonists from different sample libraries.

CONCLUSIONHuman HDL receptor CLA-1 was successfully expressed in Sf9 insect cells and a novel high-throughput screening model for CLA-1 agonists was developed. Utilization of this model allows us to identify potent and selective CLA-1 agonists which might possibly be used as therapeutics for atherosclerosis.

Animals ; Baculoviridae ; genetics ; metabolism ; Biological Assay ; Carbocyanines ; metabolism ; Cell Line, Tumor ; Cholesterol, HDL ; metabolism ; DNA, Complementary ; genetics ; metabolism ; Fluorescent Dyes ; metabolism ; Gene Expression ; Humans ; Lipoproteins, HDL ; agonists ; genetics ; metabolism ; Lipoproteins, LDL ; metabolism ; Receptors, Lipoprotein ; agonists ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Scavenger Receptors, Class B ; agonists ; genetics ; metabolism ; Spodoptera ; genetics ; metabolism

Familial hypercholesterolemia (FH) is a common autosomal dominant disorder caused by a defect in the low-density-lipoprotein (LDL) receptor, disrupting the normal control of cholesterol metabolism. We have collected 86 FH families for over 5 years who met following Dx criteria 1) hypercholesterolemia over 280 mg/dl 2) Achilles tendon xanthoma thicker than 9 mm, and 3) familial tendency, and characterized the pattern of mutations in Korea FH patients. METHOD: Mutation was screened with linkage analysis into two ways; large structural rearrangements were screened by genomic Southern blotting or long-PCR technique, and small structural rearrangements were screened by PCR of each exon followed by SSCP analysis. The exact mutation sites were confirmed by sequencing. RESULT: 1) Large mutation: Three different large deletions(FH110, FH29, FH32) were found in 7(11.5%) among 61 families screened. FH110 was a deletion of 5.7kb from intron 8 to 12, which was found in 5 unrelated families. FH29 was a deletion of 3.8kb from intron 6 to 8, and FH32 was a deletion of 2kb from intron 6 to 7. These three deletions have not been reported previously. The mechanism of deletion was unequal crossover from mispairing Alu-sequences. 2) Small or point mutations: Nineteen different small mutations were found in 19(31.4%) among 86 families screened . These mutations comprised 9 missense, 3 nonsense, 2 splicing mutations, 3 small deletions, and 2 small insertions. One missense mutation (Pro664Leu) was found in 6 unrelated families. Among these mutations, 12 have not been reported previously. CONCLUSIONS: LDL receptor gene mutations are heterogeneous in Korean FH patients. We could not observe founder mutation but detect common mutations.
Achilles Tendon ; Blotting, Southern ; Cholesterol ; Exons ; Humans ; Hypercholesterolemia ; Hyperlipoproteinemia Type II* ; Introns ; Korea ; Lipoproteins* ; Metabolism ; Mutation, Missense ; Point Mutation ; Polymerase Chain Reaction ; Polymorphism, Single-Stranded Conformational ; Receptors, LDL ; Receptors, Lipoprotein* ; Xanthomatosis

Familial hypercholesterolemia (FH) is a common autosomal dominant disorder caused by a defect in the low-density-lipoprotein (LDL) receptor, disrupting the normal control of cholesterol metabolism. We have collected 86 FH families for over 5 years who met following Dx criteria 1) hypercholesterolemia over 280 mg/dl 2) Achilles tendon xanthoma thicker than 9 mm, and 3) familial tendency, and characterized the pattern of mutations in Korea FH patients. METHOD: Mutation was screened with linkage analysis into two ways; large structural rearrangements were screened by genomic Southern blotting or long-PCR technique, and small structural rearrangements were screened by PCR of each exon followed by SSCP analysis. The exact mutation sites were confirmed by sequencing. RESULT: 1) Large mutation: Three different large deletions(FH110, FH29, FH32) were found in 7(11.5%) among 61 families screened. FH110 was a deletion of 5.7kb from intron 8 to 12, which was found in 5 unrelated families. FH29 was a deletion of 3.8kb from intron 6 to 8, and FH32 was a deletion of 2kb from intron 6 to 7. These three deletions have not been reported previously. The mechanism of deletion was unequal crossover from mispairing Alu-sequences. 2) Small or point mutations: Nineteen different small mutations were found in 19(31.4%) among 86 families screened . These mutations comprised 9 missense, 3 nonsense, 2 splicing mutations, 3 small deletions, and 2 small insertions. One missense mutation (Pro664Leu) was found in 6 unrelated families. Among these mutations, 12 have not been reported previously. CONCLUSIONS: LDL receptor gene mutations are heterogeneous in Korean FH patients. We could not observe founder mutation but detect common mutations.
Achilles Tendon ; Blotting, Southern ; Cholesterol ; Exons ; Humans ; Hypercholesterolemia ; Hyperlipoproteinemia Type II* ; Introns ; Korea ; Lipoproteins* ; Metabolism ; Mutation, Missense ; Point Mutation ; Polymerase Chain Reaction ; Polymorphism, Single-Stranded Conformational ; Receptors, LDL ; Receptors, Lipoprotein* ; Xanthomatosis

OBJECTIVETo establish a new drug screening model based on transcriptional regulation of human high density lipoprotein (HDL) receptor gene CD36 and LIMPII analogous-1 (CLA-1) for discovering up-regulator of this receptor.

METHODSThe upstream regulatory sequence of CLA-1 was obtained by polymerase chain reaction. A recombinant reporter plasmid pGL3-CLAP was constructed by inserting the regulatory sequence upstream of luciferase gene of pGL3-Basic. Human hepatoma cell line BEL-7402 was transfected with pGL3-CLAP. Samples were detected by testing luciferase activity of transfected BEL-7402 cells in microtiter wells.

RESULTSThe drug screening model was established and optimized. Significant difference was present between pGL3-CLAP and pGL3-Basic transfected BEL-7402 cells (P< 0.001), and coefficient of variation was less than 10%. After primary and secondary screening, 1 compounds and 3 fermentation extracts had up-regulating activities.

CONCLUSIONThis new drug screening model may be efficiently used to screen up-regulators of human HDL receptor expression, which might become lead compounds for new anti-atherosclerosis drugs.

CD36 Antigens ; Cholesterol Esters ; metabolism ; Drug Evaluation, Preclinical ; methods ; Gene Expression Regulation ; drug effects ; Humans ; Hypolipidemic Agents ; chemical synthesis ; pharmacology ; Lipoproteins, HDL ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA-Binding Proteins ; Receptors, Immunologic ; genetics ; Receptors, Lipoprotein ; genetics ; Receptors, Scavenger ; Scavenger Receptors, Class B ; Transcription, Genetic ; drug effects ; Up-Regulation

Cholesterol is an essential component for neuronal physiology not only during development stage but also in the adult life. Cholesterol metabolism in brain is independent from that in peripheral tissues due to blood-brain barrier. The content of cholesterol in brain must be accurately maintained in order to keep brain function well. Defects in brain cholesterol metabolism has been shown to be implicated in neurodegenerative diseases, such as Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), and some cognitive deficits typical of the old age. The brain contains large amount of cholesterol, but the cholesterol metabolism and its complex homeostasis regulation are currently poorly understood. This review will seek to integrate current knowledge about the brain cholesterol metabolism with molecular mechanisms.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Alzheimer Disease ; genetics ; metabolism ; pathology ; Blood-Brain Barrier ; Brain ; metabolism ; pathology ; Cholesterol ; metabolism ; Gene Expression Regulation ; Homeostasis ; Humans ; Huntington Disease ; genetics ; metabolism ; pathology ; Hydroxycholesterols ; metabolism ; Lipid Metabolism ; genetics ; Neurons ; metabolism ; pathology ; Parkinson Disease ; genetics ; metabolism ; pathology ; Receptors, Lipoprotein ; genetics ; metabolism

BACKGROUND/OBJECTIVES: Corn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets. MATERIALS/METHODS: Normal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor α were determined. RESULTS: Oral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different. CONCLUSIONS: CS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.
Adipokines ; Adiponectin ; Administration, Oral ; Animals ; Blood Glucose ; Cholesterol* ; Diet ; Diet, High-Fat* ; Fatty Liver ; Glucose ; Homeostasis ; Insulin ; Leptin ; Metabolism* ; Mice* ; Oxidoreductases ; Phosphatidylcholine-Sterol O-Acyltransferase ; Receptors, Lipoprotein ; RNA, Messenger ; Silk* ; Sterol O-Acyltransferase ; Triglycerides ; Tumor Necrosis Factor-alpha ; Zea mays*

BACKGROUND: Fibrous hamartoma is the key pathology of congenital pseudarthrosis of the tibia (CPT), which was shown to have low osteogenicity and high osteoclastogenicity. This study further investigated the mechanism of impaired osteoblastic differentiation of fibrous hamartoma cells. METHODS: Fibroblast-like cells were obtained from enzymatically dissociated fibrous hamartomas of 11 patients with CPT associated with neurofibromatosis type I (NF1). Periosteal cells were also obtained from the distal tibial periosteum of 3 patients without CPT or NF1 as control. The mRNA levels of Wnt ligands and their canonical receptors, such as Lrp5 and beta-catenin, were assayed using reverse transcriptase PCR (RT-PCR). Changes in mRNA expression of osteoblast marker genes by rhBMP2 treatment were assayed using quantitative real time RT-PCR. Changes in mRNA expression of transcription factors specifically involved in osteoblastic differentiation by rhBMP2 treatment was also assayed using quantitative real-time RT-PCR. RESULTS: Wnt1 and Wnt3a mRNA expression was lower in fibrous hamartoma than in tibial periosteal cells, but their canonical receptors did not show significant difference. Response of osteoblastic marker gene expression to rhBMP2 treatment showed patient-to-patient variability. Col1a1 mRNA expression was up-regulated in most fibrous hamartoma tissues, osteocalcin was up-regulated in a small number of patients, and ALP expression was down-regulated in most fibrous hamartoma tissues. Changes in mRNA expression of the transcription factors in response to rhBMP2 also showed factor-to-factor and patient-to-patient variability. Dlx5 was consistently up-regulated by rhBMP2 treatment in all fibrous hamartoma tissues tested. Msx2 expression was down-regulated by rhBMP2 in most cases but by lesser extent than control tissue. Runx2 expression was up-regulated in 8 out of 18 fibrous hamartoma tissues tested. Osterix expression was up-regulated in 2 and down-regulated in 3 fibrous hamartoma tissues. CONCLUSIONS: Congenital pseudarthrosis of the tibia appears to be caused by fibrous hamartoma originating from aberrant growth of Nf1 haploinsufficient periosteal cells, which failed in terminal osteoblastic differentiation and arrested at a certain stage of this process. This pathomechanism of CPT should be targeted in the development of novel therapeutic biologic intervention.
Adolescent ; *Cell Differentiation ; Cells, Cultured ; Child ; Child, Preschool ; Female ; Hamartoma/complications/*pathology ; Humans ; Infant ; Low Density Lipoprotein Receptor-Related Protein-5/metabolism ; Male ; Neurofibromatosis 1/complications/*pathology ; Osteoblasts/*pathology ; Periosteum/pathology ; Pseudarthrosis/complications/*congenital/pathology/physiopathology ; Receptors, Wnt/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tibia/*pathology ; Transcription Factors/metabolism ; Wnt1 Protein/metabolism ; Wnt3A Protein/metabolism ; beta Catenin/metabolism