• Molecules and Cells
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• 제37권8호
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• pp.613-619
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• 2014

The optic nerve often suffers regenerative failure after injury, leading to serious visual impairment such as glaucoma. The main inhibitory factors, including Nogo-A, oligodendrocyte myelin glycoprotein, and myelin-associated glycoprotein, exert their inhibitory effects on axonal growth through the same receptor, the Nogo-66 receptor (NgR). Oncomodulin (OM), a calcium-binding protein with a molecular weight of an ~12 kDa, which is secreted from activated macrophages, has been demonstrated to have high and specific affinity for retinal ganglion cells (RGC) and promote greater axonal regeneration than other known polypeptide growth factors. Protamine has been reported to effectively deliver small interference RNA (siRNA) into cells. Accordingly, a fusion protein of OM and truncated protamine (tp) may be used as a vehicle for the delivery of NgR siRNA into RGC for gene therapy. To test this hypothesis, we constructed OM and tp fusion protein (OM/tp) expression vectors. Using the indirect immunofluorescence labeling method, OM/tp fusion proteins were found to have a high affinity for RGC. The gel shift assay showed that the OM/tp fusion proteins retained the capacity to bind to DNA. Using OM/tp fusion proteins as a delivery tool, the siRNA of NgR was effectively transfected into cells and significantly down-regulated NgR expression levels. More importantly, OM/tp-NgR siRNA dramatically promoted axonal growth of RGC compared with the application of OM/tp recombinant protein or NgR siRNA alone in vitro. In addition, OM/tp-NgR siRNA highly elevated intracellular cyclic adenosine monophosphate (cAMP) levels and inhibited activation of the Ras homolog gene family, member A (RhoA). Taken together, our data demonstrated that the recombinant OM/tp fusion proteins retained the functions of both OM and tp, and that OM/tp-NgR siRNA might potentially be used for the treatment of optic nerve injury.

• BMB Reports
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• 제43권10호
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• pp.656-663
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• 2010

Amyloid precursor protein (APP), which is critically involved in the pathogenesis of Alzheimer's disease (AD), is cleaved by gamma/epsilon-secretase activity and results in the generation of different lengths of the APP Intracellular C-terminal Domain (AICD). In spite of its small size and short half-life, AICD has become the focus of studies on AD pathogenesis. Recently, it was demonstrated that AICD binds to different intracellular binding partners ('adaptor protein'), which regulate its stability and cellular localization. In terms of choice of adaptor protein, phosphorylation seems to play an important role. AICD and its various adaptor proteins are thought to take part in various cellular events, including regulation of gene transcription, apoptosis, calcium signaling, growth factor, and $NF-{\kappa}B$ pathway activation, as well as the production, trafficking, and processing of APP, and the modulation of cytoskeletal dynamics. This review discusses the possible roles of AICD in the pathogenesis of neurodegenerative diseases including AD.

• 한국치위생학회지
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• 제11권4호
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• pp.419-426
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• 2011

Originally, vitamin K was defined as a factor for blood coagulation. Now more attention is focused on vitamin K for bone metabolism and bone health. Vitamin K is a coenzyme for glutamate carboxylase which converts glutamate residues to ${\gamma}$-carboxyglutamate(Gla) residues. Gla residues have calcium binding ability and bound to hydroxyapatite crystals in bone. Vitamin K promotes the carboxylation of osteocalcin and matrix Gla-protein, vitamin K-dependent proteins and improves bone mineral density and bone mass. Vitamin K deficiency causes reductions in bone mineral density and increases the risk of osteoporotic bone fractures, resulting from undercarboxylated osteocalcin. This paper is to provide a brief information of vitamin K and its role in bone health.

• BMB Reports
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• 제37권6호
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• pp.741-748
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• 2004

The hepatitis C virus is associated with the development of liver cirrhosis and hepatocellular carcinomas. Among the 10 polyproteins produced by the virus, no function has been clearly assigned to the non-structural 5A (NS5A) protein. This study was designed to identify the hepatocellular proteins that interact with NS5A of the HCV. Yeast two-hybrid experiments were performed with a human liver cDNA prey-library, using five different NS5A derivatives as baits, the full-length NS5A (NS5A-F, amino acid (aa) 1~447) and its four different derivatives, denoted as NS5A-A (aa 1~150), -B (aa 1~300), -C (aa 300~447) and D (aa 150~447). NS5A-F, NS5A-B and NS5A-C gave two, two and 10 candidate clones, respectively, including an AHNAK-related protein, the secreted frizzled-related protein 4 (SFRP4), the N-myc downstream regulated gene 1 (NDRG1), the cellular retinoic acid binding protein 1 (CRABP-1), ferritin heavy chain (FTH1), translokin, tumor-associated calcium signal transducer 2 (TACSTD2), phosphatidylinositol 4-kinase (PI4K) and $centaurin{\delta}$ 2 ($CENT{\delta}2$). However, NS5A-A produced no candidates and NS5A-D was not suitable as bait due to transcriptional activity. Based on an in vitro binding assay, CRABP-1, PI4K, $CENT{\delta}2$ and two unknown fusion proteins with maltose binding protein (MBP), were confirmed to interact with the glutathione S-transferase (GST)/NS5A fusion protein. Furthermore, the interactions of CRABP-1, PI4K and $CENT{\delta}2$ were not related to the PXXP motif (class II), as judged by a domain analysis. While their biological relevance is under investigation, the results contribute to a better understanding of the possible role of NS5A in hepatocellular signaling pathways.

• Applied Microscopy
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• 제41권4호
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• pp.235-248
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• 2011

외상성 뇌손상(traumatic brain injury, TBI)은 다양한 외부요인에 의해 나타나는 직접적인 뇌조직 손상으로, 변성된 뇌신경세포의 지연성 병태생리학적인 변화를 수반하는 질환으로 잘 알려져 있다. 이러한 뇌손상은 그 정도에 따라 인지기능저하 및 운동능력의 손상을 야기하는 것으로 알려져 있으며, 특히, 일부 환자에서는 뇌손상 후유증으로 회귀성 간질발작 증상이 나타나는 것으로 알려 있다. 외상성 뇌손상 후 간질발생기전에 대한 연구에서 GABAergic interneurons의 손상과 다양한 종류의 억제성 사이신경의 작용이 간질질환의 발병에 매우 중요한 역할을 하는 것으로 알려져 있다. 따라서, 본 연구에서는 외상성 뇌손상 후 초기단계에서 칼슘결합단백질이 발현되는 GABAergic interneurons의 면역반응성이 어떠한 변화를 나타내는지를 분석하고, 이와 같은 발현변화가 외상성 손상 후 간질발생 및 전파에 미치는 영향을 분석하여 이들 사이의 연관성을 규명하기 위하여 연구를 수행하였다. 연구결과 극저온으로 외상성 뇌손상을 주었을 때 극저온 손상에 노출된 대뇌의 해마에서 parvalbumin (PV) 및 calbindin D-28k (CB)와 같은 칼슘결합단백질의 발현이 시간경과에 따라 다양하게 변화되는 것을 확인 할 수 있었다. 극저온에 노출되어 손상을 받은 부위는 뇌손상 후 30분경에 대조군에 비해 PV 및 CB의 발현이 현저하게 감소하였으며, 이들에 면역반응성을 나타내는 신경세포의 숫자도 시간경과에 따라 감소하였으나, 시간이 경과함에 따라 정상수준으로 회복되었다. 그러나, 외상성 뇌손상에 노출되지 않은 반대측 해마에서는 CB의 면역반응성에는 특이한 변화가 없는 반면, PV의 발현은 뇌손상 후 1일 이후부터 대조군에 비해 특이하게 감소하였다. 따라서, 이 실험의 결과는 뇌손상후 해마에서 나타나는 칼슘결합단백질의 감소가 $GABA_A$ receptor를 통한 억제성신경전달의 감소에 관여하고, 이러한 작용에 의해 일시적으로 해마내 신경세포들의 과흥분성 신경전달이 증가하는 것으로 생각된다. 또한, 외상성 뇌손상에 노출되지 않은 반대측 해마에서 나타나는 PV 면역반응 신경세포의 감소는 외상성 뇌손상에 노출된 동측 해마에서 나타나는 칼슘결합단백질의 변화와 함께 외상성 뇌손상 후 간질발생에 중요한 역할을 할 것으로 생각된다.

• Molecules and Cells
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• 제25권3호
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• pp.390-396
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• 2008

Calreticulin (CRT) is one of the major $Ca^{2+}$ binding chaperone proteins of the endoplasmic reticulum (ER) and an unusual luminal ER protein. Postnatally elevated expression of CRT leads to impaired development of the cardiac conductive system and may be responsible for the pathology of complete heart block. In this study, the molecular mechanisms that affect $Ca^{2+}$-dependent signal cascades were investigated using CRT-overexpressing cardiomyocytes. In particular, we asked whether calreticulin plays a critical role in the activation of $Ca^{2+}$-dependent apoptosis. In the cells overexpressing CRT, the intracellular calcium concentration was significantly increased and the activity of PKC and level of SECAR2a mRNA were reduced. Phosphorylation of Akt and ERKs decreased compared to control. In addition the activity of the anti-apoptotic factor, Bcl-2, was decreased and the activities of pro-apoptotic factor, Bax, p53 and caspase 8 were increased, leading to a dramatic augmentation of caspase 3 activity. Our results suggest that enhanced CRT expression in mature cardiomyocytes disrupts intracellular calcium regulation, leading to calcium-dependent apoptosis.

• Molecules and Cells
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• 제20권2호
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• pp.219-227
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• 2005

Purkinje cell degeneration (pcd) mice are characterized by death of virtually all cerebellar Purkinje cells by postnatal day 30. In this study, we used DNA microarray analysis to investigate differences in gene expression between the brains of wild type and pcd mice on postnatal day 20, before the appearance of clear-cut phenotypic abnormalities. We identified 300 differentially expressed genes, most of which were involved in metabolic and physiological processes. Among the differentially expressed genes were several calcium binding proteins including calbindin-28k, paravalbumin, matrix gamma-carboxyglutamate protein and synaptotagamins 1 and 13, suggesting the involvement of abnormal $Ca^{2+}$ signaling in the pcd phenotype.

• BMB Reports
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• 제51권1호
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• pp.5-13
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• 2018

Formation of toxic protein aggregates is a common feature and mainly contributes to the pathogenesis of neurodegenerative diseases (NDDs), which include amyotrophic lateral sclerosis (ALS), Alzheimer's, Parkinson's, Huntington's, and prion diseases. The transglutaminase 2 (TG2) gene encodes a multifunctional enzyme, displaying four types of activity, such as transamidation, GTPase, protein disulfide isomerase, and protein kinase activities. Many studies demonstrated that the calcium-dependent transamidation activity of TG2 affects the formation of insoluble and toxic amyloid aggregates that mainly consisted of NDD-related proteins. So far, many important and NDD-related substrates of TG2 have been identified, including $amlyoid-{\beta}$, tau, ${\alpha}-synuclein$, mutant huntingtin, and ALS-linked trans-activation response (TAR) DNA-binding protein 43. Recently, the formation of toxic inclusions mediated by several TG2 substrates were efficiently inhibited by TG2 inhibitors. Therefore, the development of highly specific TG2 inhibitors would be an important tool in alleviating the progression of TG2-related brain disorders. In this review, the authors discuss recent advances in TG2 biochemistry, several mechanisms of molecular regulation and pleotropic signaling functions, and the presumed role of TG2 in the progression of many NDDs.

• 통합자연과학논문집
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• 제15권2호
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• pp.63-72
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• 2022

To elucidate the neurochemical characteristics of the midbrain periaqueductal gray (PAG), the distribution patterns of several neuroanatomical markers within the PAG were compared. Immunohistochemical staining for the intracellular calcium binding proteins including calbindin, calretinin, and parvalbumin and histochemical staining for cytochrome oxidase, acetylcholinesterase, and NADPH-diaphorase were performed in. Each chemical substance were localized in the specific subregions within PAG. Calbindin- immunoreactivity were selectively distributed in the dorsolateral PAG, the ventral half of lateral PAG, the ventralateral PAG, and supraoculomotor cap (Su3C) nucleus. Distribution of calretinin-immunoreactivity were generally similar with that of clabindin, but showed relatively low subregional selectivity. Parvalbumin-immunoreactivity was very poor within the PAG. High reactivity of cytochrome oxidase were found in the dorsomedial PAG and the lateral half of lateral PAG, in which calbindin- and calretinin-immunoreactive perikarya were scarcely observed. Acetylcholinesterase distribution was similar with that of cytochrome oxidase, and the difference was in the additional marking of of Su3C with acetylcholinesterase. Results of the present study provides data for the further subdivisions of the territory of the PAG compared to the presently accepted subregions within the PAG.

• Natural Product Sciences
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• 제29권2호
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• pp.104-112
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• 2023

COVID-19 caused a catastrophe in human health. People infected with COVID-19 also suffer from various clinical illnesses during and after the infection. The Boerhavia diffusa plant is well known for its antihypertensive activity. ACE-II inhibitors and calcium channel blockers are reported as mechanisms for the antihypertensive activity of B. diffusa phytoconstituents. Various studies have said ACE-II is the virus's binding site to attack host cells. COVID-19 treatment commonly employs a variety of synthetic antiviral and steroidal drugs. As a result, other clinical illnesses, such as hypertension and hyperglycemia, emerge as serious complications. Safe and effective drug delivery is a prime objective of the drug development process. COVID-19 is treated with various herbal treatments; however, they are not widely used due to their low potency. Many herbal plants and formulations are used to treat COVID-19 infection, in which B. diffusa is the most widely used plant. The current study relies on discovering active phytoconstituents with ACE-II inhibitory activity in the B. diffusa plant. As a result, it can be used as a treatment option for patients with COVID-19 and related diseases. Different phytoconstituents of the B. diffusa plant were selected from the reported literature. The activity of phytoconstituents against ACE-II proteins has been studied. Molecular docking and ligand-protein interaction computation tools are used in the in-silico experiment. Physicochemical, drug-likeness, water solubility, lipophilicity, and pharmacokinetic parameters are used to evaluate phytoconstituents. Liriodenine has the best drug-likeness, bioactivity, and binding score characteristics among the selected ligands. The in-silico study aims to find the therapeutic potential of B. diffusa phytoconstituents against ACE-II. Targeting ACE-II also shows an effect against SARS-CoV-2. It can serve as a rationale for designing a drug for patient infected with COVID-19 and associated diseases.