Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
Add more filters










Publication year range
1.
Sci Rep ; 14(1): 12451, 2024 05 30.
Article in English | MEDLINE | ID: mdl-38816469

ABSTRACT

The FZP gene plays a critical role in the formation of lateral branches and spikelets in rice panicle architecture. This study investigates the qSBN7 allele, a hypomorphic variant of FZP, and its influence on panicle architectures in different genetic backgrounds. We evaluated two backcross inbred lines (BILs), BC5_TCS10sbn and BC3_TCS10sbn, each possessing the homozygous qSBN7 allele but demonstrating differing degrees of spikelet degeneration. Our analysis revealed that BC5_TCS10sbn had markedly low FZP expression, which corresponded with an increase in axillary branches and severe spikelet degeneration. Conversely, BC3_TCS10sbn exhibited significantly elevated FZP expression, leading to fewer secondary and tertiary branches, and consequently decreased spikelet degeneration. Compared to BC5_TCS10sbn, BC3_TCS10sbn carries three additional chromosomal substitution segments from its donor parent, IR65598-112-2. All three segments significantly enhance the expression of FZP and reduce the occurrence of tertiary branch and spikelet degeneration. These findings enhance our understanding of the mechanisms regulating FZP and aid rice breeding efforts.


Subject(s)
Oryza , Oryza/genetics , Oryza/growth & development , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant , Alleles , Genetic Background , Plant Breeding , Genes, Plant , Genome, Plant , Phenotype
2.
Materials (Basel) ; 16(17)2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37687626

ABSTRACT

Ti-based metallic glasses have a high potential for implant applications. The feasibility of a new biocompatible Ti-based bulk metallic glass composite for selective laser melting (SLM) had been examined. Therefore, it is necessary to design a high-glass-forming-ability Ti-based metallic glass (∆Tx = 81 K, γ = 0.427, γm = 0.763), to fabricate a partial glass-formable spherical powder (the volume fraction of the amorphous phase in the atomized Ti-based powders being 73% [size < 25 µm], 61% [25-37 µm], and 50% [37-44 µm]), and establish an SLM parameter (a scan rate of 600 mm/s, a power of 120 W, and an overlap of 10%). The Ti42Zr35Si5Co12.5Sn2.5Ta3 bulk metallic glass composite was successfully fabricated through SLM. This study demonstrates that the TiZrSiCoSnTa system constitutes a promising basis for the additive manufacturing process in terms of preparing biocompatible metallic glass composites into complicated graded foam shapes.

3.
Materials (Basel) ; 15(18)2022 Sep 12.
Article in English | MEDLINE | ID: mdl-36143635

ABSTRACT

Most medium entropy alloys (MEAs) exhibit excellent mechanical properties, but their applications are limited because of their high density. This study explores a series of lightweight nonequiatomic Ti65(AlCrNbV)35-xZrx (x = 3, 5, 7, and 10) MEAs with a low density, high strength, and high ductility. To achieve solid solution strengthening, Zr with a large atomic radius was used. In addition, various thermomechanical treatment parameters were adopted to further improve the MEAs' mechanical properties. The density of the MEAs was revealed to be approximately 5 g/cm3, indicating that they were lightweight. Through an X-ray diffraction analysis, the MEAs were revealed to have a single body-centered cubic structure not only in the as-cast state but also after thermomechanical treatment. In terms of mechanical properties, all the as-cast MEAs with Zr additions achieved excellent performance (>1000 MPa tensile yield strength and 20% tensile ductility). In addition, hot rolling effectively eliminated the defects of the MEAs; under a given yield strength, hot-rolled MEAs exhibited superior ductility relative to non-hot-rolled MEAs. Overall, the Ti65(AlCrNbV)28Zr7 MEAs exhibited an optimum combination of mechanical properties (yield strength > 1200 MPa, plastic strain > 15%) after undergoing hot rolling 50%, cold rolling 70%, and rapid annealing for 30 to 50 s (at a temperature of approximately 850 °C) with a heating rate of 15 K/s. With their extremely high specific yield strength (264 MPa·g/cm3) and high ductility (22%), the Ti65(AlCrNbV)28Zr7 MEAs demonstrate considerable potential for energy and transportation applications.

4.
J Clin Invest ; 132(15)2022 08 01.
Article in English | MEDLINE | ID: mdl-35912861

ABSTRACT

Over the last 2 decades, omalizumab is the only anti-IgE antibody that has been approved for asthma and chronic spontaneous urticaria (CSU). Ligelizumab, a higher-affinity anti-IgE mAb and the only rival viable candidate in late-stage clinical trials, showed anti-CSU efficacy superior to that of omalizumab in phase IIb but not in phase III. This report features the antigenic-functional characteristics of UB-221, an anti-IgE mAb of a newer class that is distinct from omalizumab and ligelizumab. UB-221, in free form, bound abundantly to CD23-occupied IgE and, in oligomeric mAb-IgE complex forms, freely engaged CD23, while ligelizumab reacted limitedly and omalizumab stayed inert toward CD23; these observations are consistent with UB-221 outperforming ligelizumab and omalizumab in CD23-mediated downregulation of IgE production. UB-221 bound IgE with a strong affinity to prevent FcԑRI-mediated basophil activation and degranulation, exhibiting superior IgE-neutralizing activity to that of omalizumab. UB-221 and ligelizumab bound cellular IgE and effectively neutralized IgE in sera of patients with atopic dermatitis with equal strength, while omalizumab lagged behind. A single UB-221 dose administered to cynomolgus macaques and human IgE (ε, κ)-knockin mice could induce rapid, pronounced serum-IgE reduction. A single UB-221 dose administered to patients with CSU in a first-in-human trial exhibited durable disease symptom relief in parallel with a rapid reduction in serum free-IgE level.


Subject(s)
Omalizumab , Urticaria , Animals , Antibodies, Monoclonal, Humanized , Down-Regulation , Humans , Immunoglobulin E , Mice , Omalizumab/pharmacology , Omalizumab/therapeutic use , Urticaria/drug therapy , Urticaria/genetics
5.
Materials (Basel) ; 15(5)2022 Mar 03.
Article in English | MEDLINE | ID: mdl-35269119

ABSTRACT

In this study, a porous titanium zirconium (TiZr)-based bulk metallic foam was successfully fabricated using the Cu spacer by employing the hot press method. TiZr-based bulk metallic foams with porosities ranging from 0% to 50% were fabricated and analyzed. The results indicate that thermal conductivity increased with the addition of Cu spacer; the increased thermal conductivity reduced the holding time in the hot press method. Moreover, the compressive strength decreased from 1261 to 76 MPa when the porosity of the TiZr-based bulk metallic foam increased to 50%, and the compressive strength was predictable. In addition, the foam demonstrated favorable biocompatibility in cell viability, cell migration capacity, and calcium deposition tests. Moreover, the pore size of the porous TiZr-based bulk metallic foam was around 120 µm. In conclusion, TiZr-based bulk metallic foam has favorable biocompatibility, mechanical property controllability, and porous structure for bone ingrowth and subsequent enhanced osteointegration. This porous TiZr-based bulk metallic foam has great potential as an orthopedic implant to enhance bone healing and decrease healing time.

6.
Materials (Basel) ; 14(15)2021 Jul 28.
Article in English | MEDLINE | ID: mdl-34361417

ABSTRACT

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50-Ti-Cr-Mn-V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.

7.
Entropy (Basel) ; 22(1)2020 Jan 06.
Article in English | MEDLINE | ID: mdl-33285849

ABSTRACT

A novel lightweight Al-Ti-Cr-Mn-V medium-entropy alloy (MEA) system was developed using a nonequiatiomic approach and alloys were produced through arc melting and drop casting. These alloys comprised a body-centered cubic (BCC) and face-centered cubic (FCC) dual phase with a density of approximately 4.5 g/cm3. However, the fraction of the BCC phase and morphology of the FCC phase can be controlled by incorporating other elements. The results of compression tests indicated that these Al-Ti-Cr-Mn-V alloys exhibited a prominent compression strength (~1940 MPa) and ductility (~30%). Moreover, homogenized samples maintained a high compression strength of 1900 MPa and similar ductility (30%). Due to the high specific compressive strength (0.433 GPa·g/cm3) and excellent combination of strength and ductility, the cast lightweight Al-Ti-Cr-Mn-V MEAs are a promising alloy system for application in transportation and energy industries.

8.
mSphere ; 5(5)2020 10 14.
Article in English | MEDLINE | ID: mdl-33055259

ABSTRACT

Streptococcus parasanguinis is a dominant isolate of dental plaque and an opportunistic pathogen associated with subacute endocarditis. As the expression of collagen binding proteins (CBPs) could promote the establishment of S. parasanguinis in the host, the functions of three putative CBP-encoding loci, Spaf_0420, Spaf_1570, and Spaf_1573, were analyzed using isogenic mutant strains. It was revealed that S. parasanguinis FW213 bound effectively to fibronectin and type I collagen, but the strain's affinity for laminin and type IV collagen was quite low. By using various deletion derivatives, it was found that these three loci mediated the binding of S. parasanguinis to multiple extracellular matrix molecules, with type I collagen as the common substrate. Derivative strains with a deletion in any of the three loci expressed reduced binding to trypsin-treated swine heart valves. The deletion of these loci also reduced the viable count of S. parasanguinis bacteria within macrophages, especially the loss of Spaf_0420, but only strains with deletions in Spaf_0420 and Spaf_1570 expressed reduced virulence in the Galleria mellonella larva model. The deletion of Spaf_1570 and Spaf_1573 affected mainly the structure, but not the overall mass, of biofilm cultures in a flow cell system. Thus, CBPs are likely to be more critical for the initial colonization of S. parasanguinis on host tissues during the development of endocarditis.IMPORTANCE Bacteria generally can utilize multiple adhesins to establish themselves in the host. We found that Streptococcus parasanguinis, a dominant oral commensal and an opportunistic pathogen for subacute endocarditis, possesses at least three collagen-binding proteins that enable S. parasanguinis to successfully colonize damaged heart tissues and escape innate immune clearance. The binding specificities of these three proteins for extracellular matrix molecules differ, although all three proteins participate in biofilm formation by S. parasanguinis The "multiligand for multisubstrate" feature of these adhesins may explain the high adaptability of this microbe to different tissue sites.


Subject(s)
Bacterial Proteins/metabolism , Carrier Proteins/metabolism , Collagen/metabolism , Host-Pathogen Interactions , Streptococcus/metabolism , Adhesins, Bacterial , Animals , Bacterial Adhesion , Bacterial Proteins/genetics , Biofilms/growth & development , Carrier Proteins/genetics , Larva/microbiology , Moths/microbiology , Protein Binding , Streptococcus/genetics , Virulence
9.
Curr Microbiol ; 77(11): 3430-3440, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32761388

ABSTRACT

Streptococcus parasanguinis is a primary colonizer of dental plaque and an opportunistic pathogen for subacute endocarditis. A putative fibronectin binding protein (Spaf_1409) that lacks both an N-terminal signal peptide and a C-terminal cell wall-anchoring motif was identified from the S. parasanguinis FW213 genome. Spaf_1409 was abundantly present in the cytoplasm and also was found in the cell wall preparation and culture supernatant. By using an isogenic mutant strain, MPH4, Spaf_1409 was found to mediate the binding of S. parasanguinis FW213 to fibronectin. Inactivation of Spaf_1409 did not significantly alter the mass of static biofilm, but reduced the resistance of S. parasanguinis against the shearing force in a flow cell biofilm system, resulting in scattered biofilm. The mortality in Galleria mellonella larvae infected with MPH4 was higher than in those infected with wild-type S. parasanguinis. However, fewer viable bacterial cells were recovered from larvae infected with MPH4, compared to those infected with wild-type S. parasanguinis, up to 42 h post infection, suggesting that the infection by MPH4, but not the growth, was responsible for the elevated mortality. The phagocytic analysis using flow cytometry indicated that Spaf_1409 participates in the recognition of S. parasanguinis FW213 by RAW264.7 macrophages, suggesting that inactivation of Spaf_1409 intensified the immune responses in larvae, leading to larval death. Taken together, the data indicate that Spaf_1409 plays different roles in the development of dental biofilm and in systemic infections.


Subject(s)
Carrier Proteins , Fimbriae Proteins , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Fibronectins , Fimbriae Proteins/metabolism , Streptococcus/metabolism
10.
J Funct Biomater ; 11(2)2020 May 01.
Article in English | MEDLINE | ID: mdl-32370007

ABSTRACT

A series of biocompatible high-porosity (up to 72.4%) TiZr-based porous bulk metallic glass (BMG) scaffolds were successfully fabricated by hot pressing a mixture of toxic element-free TiZr-based BMG powder and an Al particle space holder. The morphology of the fabricated scaffolds was similar to that of human bones, with pore sizes ranging from 75 to 250 µm. X-ray diffraction patterns and transmission electron microscopy images indicated that the amorphous structure of the TiZr-based BMG scaffolds remained in the amorphous state after hot pressing. Noncytotoxicity and extracellular calcium deposition of the TiZr-based BMG scaffolds at porosities of 32.8%, 48.8%, and 64.0% were examined by using the direct contact method. The results showed that the BMG scaffolds possess high cell viability and extracellular calcium deposition with average cell survival and deposition rates of approximately 170.1% and 130.9%, respectively. In addition, the resulting TiZr-based BMG scaffolds exhibited a considerable reduction in Young's moduli from 56.4 to 2.3 GPa, compressive strength from 979 to 19 MPa, and bending strength from 157 MPa to 49 MPa when the porosity was gradually increased from 2.0% to 72.4%. Based on the aforementioned specific characteristics, TiZr-based BMG scaffolds can be considered as potential candidates for biomedical applications in the human body.

11.
Mater Sci Eng C Mater Biol Appl ; 111: 110783, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32279749

ABSTRACT

Mg-based bulk metallic glass (BMG) and its composites have been promising candidates for orthopedic fixation implants because of their biocompatibility, low degradation rate, and osteogenic potential. However, the amorphous state is affected by the cooling rate during the casting process. Solid, unstable structures combined with amorphous and crystalline structures are generated when an insufficient cooling rate is used. Here, we aimed to design and synthesize a novel core-shell structure comprising an amorphous shell and a crystalline core in order to overcome the material size limit imposed by the cooling rate effects. Our results show that the core-shell structure of Mg-based BMG does have a lower degradation rate and can maintain a more amorphous structure after six weeks of degradation. Moreover, the biocompatibility and osteogenic effects were similar between the core-shell and solid structures of Mg-based BMG. In conclusion, the core-shell structure of Mg-based BMG exhibits a lower degradation rate while still enhancing osteogenic potential in vitro. This core-shell structure of Mg-based BMG overcomes the cooling rate effects and provides a new structure for manufacturing Mg-based BMG.


Subject(s)
Glass/chemistry , Magnesium/chemistry , Orthopedic Fixation Devices , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Line , Cell Survival/drug effects , Compressive Strength , Humans , Osteogenesis/drug effects , Phase Transition , Surface Properties , Temperature , Zirconium/chemistry
12.
Materials (Basel) ; 13(5)2020 Mar 06.
Article in English | MEDLINE | ID: mdl-32155846

ABSTRACT

Mg-based bulk metallic glass materials have been investigated for their large potential for application in orthopedic implants due to their biocompatibility, low degradation rate, and osteogenetic ability. As an orthopedic implant, initial cell adhesion has been a critical issue for subsequent osteogenesis and bone formation because the first contact between cells and the implant occurs upon the implants surface. Here, we aimed to create Mg-based bulk metallic glass samples with three different surface roughness attributes in order to understand the degradation behavior of Mg-based bulk metallic glass and the adhesion ability and osteogenetic ability of the contact cells. It was found that the degradation behavior of Mg66Zn29Ca5 bulk metallic glass was not affected by surface roughness. The surface of the Mg66Zn29Ca5 bulk metallic glass samples polished via #800 grade sandpaper was found to offer a well-attached surface and to provide a good cell viability environment for Human MG63 osteoblast-like cell line. In parallel, more calcium and mineral deposition was investigated on extracellular matrix with higher surface roughness that verify the relationship between surface roughness and cell performance.

13.
Int J Mol Sci ; 20(9)2019 May 03.
Article in English | MEDLINE | ID: mdl-31058825

ABSTRACT

Mg-based alloys have great potential for development into fixation implants because of their highly biocompatible and biodegradable metallic properties. In this study, we sought to determine the biocompatibility of Mg60Zn35Ca5 bulk metallic glass composite (BMGC) with fabricated implants in a rabbit tendon-bone interference fixation model. We investigated the cellular cytotoxicity of Mg60Zn35Ca5 BMGC toward rabbit osteoblasts and compared it with conventional titanium alloy (Ti6Al4V) and polylactic acid (PLA). The results show that Mg60Zn35Ca5 BMGC may be classed as slightly toxic on the basis of the standard ISO 10993-5. We further characterized the osteogenic effect of the Mg60Zn35Ca5 BMGC extraction medium on rabbit osteoblasts by quantifying extracellular calcium and mineral deposition, as well as cellular alkaline phosphatase activity. The results of these tests were found to be promising. The chemotactic effect of the Mg60Zn35Ca5 BMGC extraction medium on rabbit osteoblasts was demonstrated through a transwell migration assay. For the in vivo section of this study, a rabbit tendon-bone interference fixation model was established to determine the biocompatibility and osteogenic potential of Mg60Zn35Ca5 BMGC in a created bony tunnel for a period of up to 24 weeks. The results show that Mg60Zn35Ca5 BMGC induced considerable new bone formation at the implant site in comparison with conventional titanium alloy after 24 weeks of implantation. In conclusion, this study revealed that Mg60Zn35Ca5 BMGC demonstrated adequate biocompatibility and exhibited significant osteogenic potential both in vitro and in vivo. These advantages may be clinically beneficial to the development of Mg60Zn35Ca5 BMGC implants for future applications.


Subject(s)
Biocompatible Materials/chemistry , Calcium/chemistry , Glass/chemistry , Magnesium/chemistry , Metal Nanoparticles/chemistry , Osteogenesis/drug effects , Zinc/chemistry , Animals , Biocompatible Materials/pharmacology , Biomarkers , Bone and Bones/diagnostic imaging , Bone and Bones/metabolism , Cell Movement , Cell Survival/drug effects , Extracellular Matrix/metabolism , Imaging, Three-Dimensional , Materials Testing , Osteoblasts/drug effects , Osteoblasts/metabolism , Rabbits , Tendons , X-Ray Microtomography
14.
ACS Comb Sci ; 17(8): 442-51, 2015 Aug 10.
Article in English | MEDLINE | ID: mdl-26161720

ABSTRACT

A sequential single-flask multicomponent reactions is highly effective for the synthesis of 1,2-dihydroisoquinolines through amidealkylation from intermediate N-acylisoquinolinium salts under mild conditions. N-Acylisoquinolinium ions and trichloromethyl-1-(1H-indol-3-yl)isoquinoline-2(1H)-carboxylate have demonstrated their reactivity toward aromatic and aliphatic π-nucleophiles. One of the 1,2-dihydroisoquinoline derivatives was found to be a potent inhibitor for transcription factor NF-κB by blocking IκBα degradation, p65 nuclear translocation, and NF-κB DNA binding in TNF-α-induced NIH 3T3 cells.


Subject(s)
Isoquinolines/chemical synthesis , Isoquinolines/pharmacology , NF-kappa B/antagonists & inhibitors , Animals , Cells, Cultured , Humans , Isoquinolines/chemistry , Mice , Molecular Structure , NF-kappa B/metabolism , NIH 3T3 Cells , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism
15.
J Org Chem ; 80(13): 6669-78, 2015 Jul 02.
Article in English | MEDLINE | ID: mdl-26029977

ABSTRACT

2-(Acylmethylene)pyrrolidine derivatives were synthesized via intermolecular decarbonylative Mannich reaction from various methyl ketones and 1-alkyl-1-pyrroliniums, generated in situ from 1-alkylprolines. This approach mimics the biosynthetic pathway and provides a direct access to a series of 2-(acylmethylene)pyrrolidine alkaloids, including hygrine, N-methylruspolinone, dehydrodarlinine, and ruspolinone.


Subject(s)
Alkaloids/chemical synthesis , Pyrrolidines/chemical synthesis , Alkaloids/chemistry , Biomimetics , Molecular Structure , Pyrrolidines/chemistry
16.
Toxicol Lett ; 217(1): 42-9, 2013 Feb 13.
Article in English | MEDLINE | ID: mdl-23237828

ABSTRACT

Suppressor of cytokine signaling (SOCS)-3 can act as a regulator of energy metabolism and cytokine signaling in fat cells. It is regulated by hormones and toxicological factors. However, the action of cycloheximide on expression of adipocyte SOCS-3 gene is unknown. Using 3T3-L1 adipocytes, we found that cycloheximide up-regulated SOCS-3 mRNA expression in dose- and time-dependent manners. Treatment with actinomycin D prevented cycloheximide-stimulated SOCS-3 mRNA expression, suggesting that the effect of cycloheximide requires new mRNA synthesis. While cycloheximide was shown to increase activities of MEK1 and JNK, signaling was demonstrated to be inhibited by pretreatment with either MEK1 inhibitors U0126 and PD98059, or with the JNK inhibitor SP600125. U0126 and PD98059, respectively, reduced cycloheximide-stimulated SOCS-3 mRNA expression, but SP600125 did not antagonize cycloheximide effect. Moreover, cycloheximide was observed to up-regulate expression of other SOCS family members, such as SOCS-1, -2, -4, -5, -6, -7, and cytokine-inducible SH2-containing protein (CIS)-1 mRNAs. Such effects varied with the dosage and duration of cycloheximide treatment. These results imply the functional MEK1/ERK-mediated pathway is necessary for the cycloheximide stimulation of SOCS-3 gene expression.


Subject(s)
Adipocytes, White/drug effects , Cycloheximide/pharmacology , Down-Regulation/drug effects , MAP Kinase Signaling System/drug effects , Protein Synthesis Inhibitors/pharmacology , Suppressor of Cytokine Signaling Proteins/metabolism , Up-Regulation/drug effects , 3T3-L1 Cells , Adipocytes, White/metabolism , Animals , Cell Line , Dactinomycin/pharmacology , Isoenzymes/genetics , Isoenzymes/metabolism , Mice , Osmolar Concentration , Protein Kinase Inhibitors/pharmacology , RNA, Messenger/metabolism , Rats , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Time Factors
17.
Planta Med ; 76(15): 1694-8, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20455202

ABSTRACT

Insulin and (-)-epigallocatechin gallate (EGCG) are reported to regulate obesity and fat accumulation, respectively. This study investigated the pathways involved in EGCG modulation of insulin-stimulated glucose uptake in 3T3-L1 and C3H10T1/2 adipocytes. EGCG inhibited insulin stimulation of adipocyte glucose uptake in a dose- and time-dependent manner. The concentration of EGCG that decreased insulin-stimulated glucose uptake by 50-60% was approximately 5-10 µM for a period of 2 h. At 10 µM, EGCG and gallic acid were more effective than (-)-epicatechin, (-)-epigallocatechin, and (-)-epicatechin 3-gallate. We identified the EGCG receptor [also known as the 67-kDa laminin receptor (67LR)] in fat cells and extended the findings for this study to clarify whether EGCG-induced changes in insulin-stimulated glucose uptake in adipocytes could be mediated through the 67LR. Pretreatment of adipocytes with a 67LR antibody, but not normal rabbit immunoglobulin, prevented the effects of EGCG on insulin-increased glucose uptake. This suggests that the 67LR mediates the effect of EGCG on insulin-stimulated glucose uptake in adipocytes. Moreover, pretreatment with an AMP-activated protein kinase (AMPK) inhibitor, such as compound C, but not with a glutathione (GSH) activator, such as N-acetyl-L-cysteine (NAC), blocked the antiinsulin effect of EGCG on adipocyte glucose uptake. These data suggest that EGCG exerts its anti-insulin action on adipocyte glucose uptake via the AMPK, but not the GSH, pathway. The results of this study possibly support that EGCG mediates fat content.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Catechin/analogs & derivatives , Glucose/metabolism , Insulin/pharmacology , Receptors, Laminin/physiology , Tea/chemistry , Animals , Catechin/chemistry , Catechin/isolation & purification , Catechin/pharmacology , Mice , Mice, Inbred C3H , NIH 3T3 Cells
SELECTION OF CITATIONS
SEARCH DETAIL
...