• Molecules and Cells
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• v.44 no.3
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• pp.168-178
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• 2021

The retinal pigment epithelium (RPE) forms a monolayer sheet separating the retina and choroid in vertebrate eyes. The polarized nature of RPE is maintained by distributing membrane proteins differentially along apico-basal axis. We found the distributions of these proteins differ in embryonic, post-natal, and mature mouse RPE, suggesting developmental regulation of protein trafficking. Thus, we deleted tumor susceptibility gene 101 (Tsg101), a key component of endosomal sorting complexes required for transport (ESCRT), in embryonic and mature RPE to determine whether ESCRT-mediated endocytic protein trafficking correlated with the establishment and maintenance of RPE polarity. Loss of Tsg101 severely disturbed the polarity of RPE, which forms irregular aggregates exhibiting non-polarized distribution of cell adhesion proteins and activation of epidermal growth factor receptor signaling. These findings suggest that ESCRT-mediated protein trafficking is essential for the development and maintenance of RPE cell polarity.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.711-717
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• 2016

Toxoplasma gondii is an obligate intracellular parasite that stimulates production of high levels of proinflammatory cytokines, which are important for innate immunity. NLRs, i.e., nucleotide-binding oligomerization domain (NOD)-like receptors, play a crucial role as innate immune sensors and form multiprotein complexes called inflammasomes, which mediate caspase-1-dependent processing of $pro-IL-1{\beta}$. To elucidate the role of inflammasome components in T. gondiiinfected THP-1 macrophages, we examined inflammasome-related gene expression and mechanisms of inflammasome-regulated cytokine $IL-1{\beta}$ secretion. The results revealed a significant upregulation of $IL-1{\beta}$ after T. gondii infection. T. gondii infection also upregulated the expression of inflammasome sensors, including NLRP1, NLRP3, NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and NAIP, in a time-dependent manner. The infection also upregulated inflammasome adaptor protein ASC and caspase-1 mRNA levels. From this study, we newly found that T. gondii infection regulates NLRC4, NLRP6, NLRP8, NLRP13, AIM2, and neuronal apoptosis inhibitor protein (NAIP) gene expressions in THP-1 macrophages and that the role of the inflammasome-related genes may be critical for mediating the innate immune responses to T. gondii infection.

• BMB Reports
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• v.31 no.1
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• pp.64-69
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• 1998

Recent studies have suggested that integrin (CR3) participates in the signal transduction pathways of certain GPI-anchored phagocytic receptors including $Fc{\gamma}RIIIB$. One consequence of this functional linkage is an inducible association between CR3 and cortical microfilaments that is triggered by $Fc{\gamma}RIIIB$ binding to immobilized immune complexes (IC). That this signaling event requires the co-expression of $Fc{\gamma}RIIIB$ with CR3 was documented by the use of NIH 3T3 transfectants expressing both CR3 and $Fc{\gamma}RIIIB$ (clone 3-23), CR3 alone (clone 3-19), and $Fc{\gamma}RIIIB$ alone (clone 3-15). Pretreatment of 3-23 cells with protein kinase inhibitors such as staurosporine and methyl 2,5-dihydroxycinnamate (MDHC) blocked IC-stimulated CR3 microfilament proximity without affecting the extent to which $Fc{\gamma}RIIIB$ constrains the lateral membrane mobility of a subset of CR3 on the cell surface (as measured in fluorescence recovery after photobleaching experiments). These data support that CR3 and $Fc{\gamma}RIIIB$ molecules are physically and functionally associated and that ligation of FcgRIIIB triggers CR3-dependent signal transduction.

• Development and Reproduction
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• v.13 no.3
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• pp.133-143
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• 2009

Pivotal roles of steroid hormones in uterine endometrial function are well established from the mouse models carrying the null mutation of their receptors. Literally androgen belongs to male but interestingly it also detected in female. The fluctuations of androgen levels are observed during reproductive cycle and pregnancy, and the functional androgen receptor is expressed in reproductive organs including uterus. Using high throughput methodology, the downstream genes of androgen have been isolated and revealed correlations between other steroid hormones. In androgen-deficient mice, uterine responses to exogenous gonadotropins are impaired and the number of pups per litter is reduced dramatically. As expected androgen has important role in decidual differentiation through AR. It regulates specific gene network during those cellular responses. Recently we examined the effects of steroid hormonal complex containing high level of androgen. Interestingly, on the contrary to the androgen-alone administration, the hormonal complex did not disturb the decidual reaction and the pubs did not show any morphological abnormality. It is suspected that the complexity of communication between other steroid hormone and their receptors are the reasons. In summary, androgen exists in female blood and it suggests the importance of androgen in female reproduction. However, the complex interactions with other hormones are not fully understood compared with estrogen and progesterone. The further studies to evaluate the possible role of androgen are needed and important to provide the in vivo rational for the prevention of associated pregnancy complications and help human's health.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1107-1112
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• 2009

The aim of this study is to develop and synthesize $5-HT_{1A}$ receptor imaging agents with WAY-100635 moiety and $^{99m}Tc(CO)_3$ core. WAY-100635 is commonly known as $5-HT_{1A}$ antagonist and its labeled compound ([$^{11}C$] WAY-100635) has been used as effective radioligand for imaging brain $5-HT_{1A}$ receptors with PET(Positron Emission Tomography). However, there are several restrictions in using a radioisotope of C-11 and requires for more effective radioisotopes and ligands. In order to produce a structure most similar to WAY-100635, WAY-100635 derivatives containing a cysteine chelator were designed and confirmed by using in silico (Hyperchem). The novel compounds (7a, 7b, 7c) were prepared in five or 7 steps with yields of 16%, 36% and 42%, respectively and radiolabeled with $[^{99m}Tc(CO)_3(H_2O)_3]^{+}$. The labeling yield was 99% for all the newly synthesized compounds. [$^{99m}Tc(CO)_3$]- WAY-100635 derivatives show a neutral charge which were confirmed by paper electrophoresis.

• KSBB Journal
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• v.13 no.4
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• pp.418-423
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• 1998

Cellular transfections with cationic liposomes are widely empolyed for gene and oligonucleotide transfer in vitro because of their safety and ease of use. However, they still suffer from the low transfection efficiency comparing with viral vectors. Substantial effort shave been focused on increasing transfection efficiency by supplementing the liposome/DNA complexes(lipoplex) with various components. In this work, we tired three kinds of supplements, Poly-L-lysine(PLL), transferrin and a mixture of anionic lipids(PS/PE/PC), to study their effects on gene transfer yield and gene expression efficiency. PLL, a polycationic polymer, enhanced gene transfer yield by 3 times but the gene expression efficiency was increased only by 1.5 times. this result implies that PLL can enhance the transfection efficiency mainly by increasing the rate of outermembrane transport of lipoplex into the cells. On the other hand, transferrin which can facilitate the gene transfer via ligand-receptor interaction gave not only increased gene transfer yield but also enhanced gen expression efficiency by 2.8 times. Transferrin seems to contribute to the escape of plasmid from endosomes through ligand-receptor recycle mechanism. When the cells were treated with a mixture of anionic lipids for 3 hours before the transfection, gene transfer yield was slightly decreased but the gene expression efficiency was enhanced by 1.9 times. This is presumably due to the accelerated liposome-plasmid dissociation by the anionic lipids, and the increased delivery of plasmid to the nucleus. According to these results, it is clear that the supplementation to ameliorate transfection efficiency with cationic liposomes should be contrived in the direction of increasing delivery of plasmid.

• Journal of Integrative Natural Science
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• v.7 no.1
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• pp.25-38
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• 2014

Amyloid-${\beta}$-peptide ($A{\beta}$) is important in the pathogenesis of Alzheimer's disease (AD). Calpain ($Ca^{2+}$-dependent protease) and caspase-8 (the initiating caspase for the extrinsic, receptor-mediated apoptosis pathway) have been implicated in $AD/A{\beta}$ toxicity. We found that $A{\beta}$ promoted degradation of calpastatin (the specific endogenous calpain inhibitor); calpastatin degradation was prevented by inhibitors of either calpain or caspase-8. The results implied a cross-talk between the two proteases and suggested that one protease was responsible for the activity of the other one. In neuron-like differentiated PC12 cells, calpain promotes active caspase-8 formation from procaspase-8 via the $A{\beta}$ and CD95 pathways, along with degradation of the procaspase-8 processing inhibitor caspase-8 (FLICE)-like inhibitory protein, short isoform (FLIPS). Inhibition of calpain (by pharmacological inhibitors and by overexpression of calpastatin) prevents the cleavage of procaspase-8 to mature, active caspase-8, and inhibits FLIPS degradation in the $A{\beta}$-treated and CD95-triggered cells. Increased cellular Ca2+ per se results in calpain activation but does not lead to caspase-8 activation or FLIPS degradation. The results suggest that procaspase-8 and FLIPS association with cell membrane receptor complexes is required for calpain-induced caspase-8 activation. The results presented here add to the understanding of the roles of calpain, caspase- 8, and CD95 pathway in $AD/A{\beta}$ toxicity. Calpain-promoted activation of caspase-8 may have implications for other types of CD95-induced cell damage, and for nonapoptotic functions of caspase-8. Inhibition of calpain may be useful for modulating certain caspase-8-dependent processes.

• Journal of Life Science
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• v.26 no.3
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• pp.364-375
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• 2016

Post-translational modification is an efficient process to rapidly transduce external stimulus into cellular response. Ubiquitination is a typical post-translational modification which is a highly conserved process in eukaryotes. UPS (Ubiquitin/Proteasome System) mediated by the ubiquitination is to target diverse cellular proteins for degradation. Among E3 ubiquitin ligases that function as the key determinant for substrate recognition, CRL (cullin–RING E3 ubiquitin ligase) is the largest family and forms the complex composed of cullin, RBX1, adaptor and substrate receptor. Although CRL1, also known as SCF complex, has been widely researched for its biological role, the functional studies of CRL4 have been relatively elusive. In Arabidopsis, there are 119 substrate receptors named DCAF (DDB1 CUL4 Associated Factor) proteins for CRL4 and a fraction of DCAF proteins have been identified for their potential functions so far. In this paper, current understanding on structure and biological roles of plant CRL4 complexes in a diverse of cellular events is reviewed, especially focusing on CRL4 substrate receptors. Moreover, the regulatory mechanism of CRL4’s activity is also introduced. These studies will be helpful to further understand the signal transduction pathways in which such CRL4 complexes are involved and give a clue to establish the action network of entire CRL4 complexes in plants.

• BMB Reports
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• v.44 no.9
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• pp.607-612
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• 2011

Several investigators have shown that CpG-DNA has outstanding effects as a Th1-responsive adjuvant and that its potent adjuvant effects are enhanced by encapsulation with a liposome of proper composition. In this study, we showed that encapsulation with phosphatidyl-${\beta}$-oleoyl-${\gamma}$-palmitoyl ethanolamine (DOPE): cholesterol hemisuccinate (CHEMS) complex enhances the immunostimulatory activity of CpG DNA and the binding of CpG-DNA to TLR9. We also examined involvement of myeloid differentiation protein (MyD88) and NF-${\kappa}B$ activation in liposome-encapsulated CpG-DNA-induced IL-8 promoter activation. In this manuscript, the natural phosphodiester bond CpG-DNA encapsulated by DOPE : CHEMS complex is designated as Lipoplex(O). Importantly, we successfully screened B cell epitopes of envelope protein (E protein) of hepatitis C virus (HCV-E) and attachment glycoprotein G of human respiratory syncytial virus (HRSV-G) by immunization with complexes of several peptides and Lipoplex(O) without carriers. Therefore, Lipoplex(O) is potentially applicable as a universal adjuvant for peptide-based epitope screening and antibody production.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.77-86
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• 2008

It's been known that overexpression of the oncoprotein Her2 (eu/ErbB2), transmembrane receptor protein, occurs in human breast cancer. Her2-positive breast cancer patients who have Her2 overexpression show less therapeutic efficacy with enhanced metathesis and increased resistance to chemotherapy. So far, a humanized monoclonal antibody against Her2 protein called Herceptin is the only drug approved by Food and Drug Administration for treatment of Her2-overexpressing breast tumors. However, antibody therapy of Herceptin may not be ideal method for therapeutic intervention of Her2 protein expression. The therapeutic intervention of Her2 protein expression may be more efficiently achieved by inhibiting the expression of Her2 gene rather than by down-regulating the Her2 protein already overexpressed. Here, we found that the interaction of two proteins of ESX (an epithelial-restricted transcription factor) and DRIP130/CRSP130/Sur2 (a Ras-linked subunit of human mediator complexes) mediates the expression of Her2 gene. The association of ESX with Sur2 is mediated by a small hydrophobic face of 8-amino acid helix in ESX, suggesting that the ESX-Sur2 interaction can be a new novel target for Her2-positive cancer. The process to develop potent ESX-Sur2 interaction inhibitors targeting for Her2-positive cancer therapeutics will be discussed.