• Journal of Pharmaceutical Investigation
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• v.34 no.2
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• pp.101-106
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• 2004

This work aims at examining the cellular uptake behavior of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles derivatized with a protein transduction domain (PTD) using HeLa cells. For this purpose, $Tat_{49-57}$ peptide derived from transcriptional activation (Tat) protein of HIV type-1 was covalently conjugated to the terminal end of PLGA. Nanoparticles were ten prepared with the $Tat_{49-57}-PLGA$ conjugates by a spontaneous phase inversion method. The prepared particles had a mean diameter of ca. 84 nm, as measured by dynamic light scattering. The interaction of the Tat-PLGA nanoparticles with cells was examined by using confocal laser scanning microscopy. It was found tat Tat-PLGA nanoparticles incubated with HeLa cells could efficiently translocate into cytoplasm, while plain PLGA nanoparticles showed negligible cellular uptake. In addition, even at $4^{\circ}C$ or in the presence of sodium azide significant cellular internalization of Tat-PLGA nanoparticles was still observed. These results indicate that a non-endocytotic translocation mechanism might be involved in the cellular uptake of Tat-PLGA nanoparticles.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.75-82
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• 2013

Previous studies have shown that Aloe QDM complex, which is consisted of chromium (Cr), aloesin (ALS) and processed Aloe vera gel (PAG), exert antidiabetic activity in a high fat diet-induced mouse model of type 2 diabetes. In this study we examined the mechanism of the antidiabetic activity of the Aloe QDM complex. Rat myoblast cell line L6 cells were cultured in the presence of Cr, ALS, and PAG alone and in combinations, and then the capability of the cells to uptake glucose was examined using radiolabeled glucose. All of the 3 agents, Cr, ALS and PAG, exerted glucose uptake-enhancing activity in L6 cells. The most potent capability to uptake glucose was observed when L6 cells were cultured with the Aloe QDM complex. The activity of the Aloe QDM complex to enhance glucose uptake was prominent in conditions where existing insulin concentrations are low. We also examined the effects of the Aloe QDM complex on the plasma membrane expression of GLUT4 in L6 cells. The Aloe QDM complex increased the content of GLUT4 in the plasma membrane, while decreasing the content of GLUT4 in the light microsome. Taken together, these results show that the antidiabetic activity of the Aloe QDM complex is at least in part due to the stimulation of glucose uptake into the muscle cells, and this activity of the Aloe QDM complex is mediated through the enhancement of the translocation of GLUT4 into the plasma membrane.

• Polymer(Korea)
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• v.36 no.5
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• pp.586-592
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• 2012

Iron oxides ($Fe_3O_4$) are metabolically secreted after endocytosed by cells, indicating no cytotoxicity. Therefore, they are widely used as a contrast agent before photographing of magnetic resonance imaging. In this study, iron oxide nanoparticles are synthesized by the co-precipitation method and subsequently immobilized with a homing peptide (AP), which specifically interacts with interleukin-4 receptor located on the membrane of endothelial and bladder cancer cells. The size of AP-immobilized iron oxide particle is about 39 nm. Intracellular uptake of the AP-immobilized iron oxide nanoparticles was investigated using bladder cancer cells and fibroblasts as the control. As the result, the nanoparticles are specificially uptaken by bladder cancer cells. However, the nanoparticles are not specificially uptaken by fibroblast. It could be said that the AP-immobilized iron oxide nanoparticles have a potential to be used as a contrast agent for early diagnosis of cancer.

• Biomolecules & Therapeutics
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• v.27 no.3
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• pp.290-301
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• 2019

Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

• BMB Reports
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• v.34 no.4
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• pp.285-292
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• 2001

Insulin stimulates glucose uptake in muscle and adipose tissue and thus maintains normal blood glucose level in our body. Derangement of this process causes many grave health problems. Insulin stimulates glucose transport primarily by recruiting GLUT4 from its intracellular storage sites to the plasma membrane. The process is complex and involves GLUT4 trafficking through multiple subcellular compartments (organelles) and many protein functions, details of which are poorly understood. This review summarizes a recent development to isolate and characterize the individual intracellular GLUT4 compartments and to illustrate how this compartmental analysis will help to identify the insulin-sensitive step or steps in the insulin-induced GLUT4 recruitment in rat adipocytes. The review does not cover the recent exciting development in identification of many proteins implicated in this process.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.329-334
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• 1999

Insulin stimulates glucose uptake in muscle and adipose cells primarily by recruiting GLUT4 from an intracellular storage pool to the plasma membrane. Dysfunction of this process known as insulin resistance causes hyperglycemia, a hallmark of diabetes and obesity. Thus the understanding of the mechanisms underlying this process at the molecular level may give an insight into the prevention and treatment of these health problems. GLUT4 in rat adipocytes, for example, constantly recycles between the cells surface and an intracellular pool by endocytosis and exocytosis, each of which is regulated by an insulin-sensitive and GLUT4-selective sorting mechanism. Our working hypothesis has been that this sorting mechanism includes a specific interaction of a cytosolic protein with the GLUT4 cytoplasmic domain. Indeed, a synthetic peptide of the C-terminal cytoplasmic domain of GLUT4 induces an insulin-like GLUT4 recruitment when introduced in rat adipocytes. Relevance of these observations to a novel euglycemic drug design is discussed.

• Journal of Pharmacopuncture
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• v.15 no.3
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• pp.13-18
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• 2012

Objectives: The purpose of this study is to examine whether Hominis Placental pharmacopuncture solution (HPPS) combined with zinc-oxide nanoparticles (ZnO NP) activates RAW 264.7 cells. Methods: We soaked ZnO nanoparticles in the Hominis Placenta pharmacopuncture solution, thereby making a combined form (ZnO NP HPPS). The effect of ZnO NP HPPS on the intracellular reactive oxygen species (ROS) production was measured by 2', 7'-dichlorofluorescin diacetate (DCFH-DA) assay. The effect of ZnO NP HPPS on NF-${\kappa}B$ was measured by using a luciferase assay. The effect of ZnO NP HPPS on the cytokine expression was assessed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The cellular uptake of ZnO NP HPPS was measured by using a flow cytometric analysis, and cellular structural alterations were analyzed by using transmission electron microscopy (TEM). Results: Neither the HPPS nor the ZnO NPs induced intracellular ROS production in RAW 264.7 cells. Neither of the materials activated NF-${\kappa}B$ or it's dependent genes, such as TNF-${\alpha}$, IL-1, and MCP-1. However, ZnO NP HPPS, the combined form of ZnO NPs and HPPS, did induce the intracellular ROS production, as well as prominently activating NF-${\kappa}B$ and it's dependent genes. Also, compared to ZnO NPs, it effectively increa-sed the uptake by RAW 264.7 cells. In addition, cellular structural alterations were observed in groups treated with ZnO NP HPPS. Conclusions: Neither ZnO NP nor HPPS activated RAW 264.7 cells, which is likely due to a low cellular uptake. The ZnO NP HPPS, however, significantly activated NF-${\kappa}B$ and up-regulated its dependent genes such as TNF-${\alpha}$, IL-1, and MCP-1. ZnO NP HPPS was also more easily taken into the RAW 264.7 cells than either ZnO NP or HPPS.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.72-81
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• 2001

Dendroaspis natriuretic peptide (DNP), recently isolated from the venom of the green Mamba snake Dendroaspis angusticeps, is a 38-amino acid peptide containing a 17-amino acid disulfide ring structure similar to that of the natriuretic peptide family. The natriuretic peptide family was known to induce histamine release from human and rat mast cells, but there are no published data concerning the effects of DNP on histamine release from mast cells. The purpose of this study is to investigate whether DNP induces the histamine release from rat peritoneal mast cells (RMPCs) and to determine the mechanism of DNP-induced histamine release from RPMCs. After treatment of the various doses of DNP in RPMCs, the mast cell degranulation was observed with inverted microscopy and the histamine release was measured by radio-enzymatic assay. Calcium uptake and intracellular cyclic GMP level were measured by radioimmunoassays. DNP induced the mast cell degranulation. DNP released the histamine and increased the calcium uptake and the level of intracellular cyclic GMP of RPMCs, in a dose-dependent manner. The results indicate that DNP is capable of inducing histamine release from RPMCs by increasing of calcium uptake and intracellular cyclic GMP level.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.173-178
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• 1995

A quantitative assay was performed on the effects of gamma-irradiation (30- 300 Gy) on intracellular proliferation of Toxoplosmn gonnii RH tachyzoites in human leukemic HL-60 cells and murine peritoneal macrophages by means of 3H-uracil uptake assay. Infected non-irradiation group (NI) and uninfected group (incubating only host cells) were prepared. The 3H-uracil uptake by tachyzoites of NI group 12-24 hrs after infection was 2,190-4,787 counts per minute for macrophages and 2,967-8,254 for HL-60 cells, whereas the irradiated tachyzoites revealed only 381-703 (100 Gy) and 218-408 (300 Gy) for macrophages, and 1,911-2,618 (30 Gy), 1,253-1,384 (70 Gyl, 1,013-1,090 (100 Gyl, and 483-588 (300 Gy) for HL-60 cells. The proliferation inhibition rate was similar in macrophages and HL-60 cells, for example, 89-94% and 80-94% respectively by 300 Gy, 12-24 hrs after infection. It is concluded that RH tachyzoites of T gondii are severely affected by gamma-irradiation in their capability of Intracellular proliferation.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.272-277
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• 2019

The effects of medium-chain enriched diacylglycerol (MCE-DAG) oil on hepatic cholesterol homeostasis were investigated. HepG2 hepatocytes were treated with either 0.5, 1.0, or $1.5{\mu}g/mL$ of MCE-DAG for 48 h. There was no evidence of cytotoxicity by MCE-DAG up to $1.5{\mu}g/mL$. The level of proteins for cholesterol uptake including CLATHRIN and LDL receptor increased by MCE-DAG in a dose-dependent manner (p<0.05). Furthermore, proprotein convertase subtilisin/kexin type 9, an inhibitor of LDLR, was dose-dependently diminished (p<0.05), indicating cholesterol clearance raised. MCE-DAG significantly increased 3-hydroxy-3-methylglutaryl-coenzyme A reductase and acetyl-CoA acetyltransferase2 (p<0.05), required for cholesterol synthesis, and their transcriptional regulator sterol regulatory element-binding protein2 (p<0.05). These findings suggest that given conditions of prolonged sterol fasting in the current study activated both hepatic cholesterol synthesis and clearance by MCE-DAG. However, total intracellular level of cholesterol was not altered by MCE-DAG. Taken together, MCE-DAG has the potential to prevent hypercholesterolemia by increasing hepatic cholesterol uptake without affecting intracellular cholesterol level.