• 한국발생생물학회지:발생과생식
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• 제13권1호
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• pp.51-57
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• 2009

큰포식세포나 혈관의 내피세포 등에서 분비되는 monocyte chemoattractant protein-1(MCP-1)은 큰포식세포의 활성을 조절하고 황체의 용해시기에는 용해를 개시, 촉진시키는 작용을 하는 것으로 알려져 있다. 그러나 아직 임신 황체나 출산 후의 황체의 발달과 유지에 대한 MCP-1의 작용기전은 확실히 알려져 있지 않다. 난포발달과정에서 큰포식세포의 역할을 알아보기 위해서 흰쥐를 실험동물로 임신시기별, 출산 후 황체에서 TUNEL 염색, ED1, ED2 및 MCP-1에 대한 면역조직화학을 실시하였다. 출산 후 황체에서 큰포식세포의 수가 의미 있게 증가하였으며, 큰포식세포에 대한 ED1, ED2의 면역반응성이 증가하였고, MCP-1의 면역반응성도 크게 증가하였다. 본 연구의 결과 출산 후 황체에서는 큰포식세포가 주로 탐식작용을 하게 되지만, 임신 황체에서는 황체의 구조와 기능을 유지하는데 주로 관여할 것으로 생각된다.

• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.227-233
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• 2007

It has been reported that hepatic glutathione (GSH) levels are decreased in diabetic patients, and glucagon increases hepatic efflux of GSH into blood. The signaling pathways responsible for mediating the glucagon effects on GSH efflux, however, are unknown. The signaling pathways involved in the regulation of GSH efflux in response to glucagon and insulin were examined in primary cultured rat hepatocytes. The GSH concentrations in the culture medium were markedly increased by the addition of glucagon, although cellular GSH levels are significantly decreased by glucagon. Insulin was also increased the GSH concentrations in the culture medium, but which is reflected in elevations of both cellular GSH and protein. Treatment of cells with 8-bromo-cAMP or dibutyryl-cAMP also resulted in elevation of the GSH concentrations in the culture medium. Pretreatment with H89, a selective inhibitor of protein kinase A, before glucagon addition markedly attenuated the glucagon effect. These results suggest that glucagon changes GSH homeostasis via elevation of GSH efflux, which may be responsible for decrease in hepatic GSH levels observed in diabetic condition. Furthermore, the present study implicates cAMP and protein kinase A in mediating the effect of glucagon on GSH efflux in primary cultured rat hepatocytes.

• Advances in nano research
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• 제7권6호
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• pp.443-457
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• 2019

In this investigation, dynamic and bending behaviors of isolated protein microtubules are analyzed. Microtubules (MTs) can be considered as bio-composite structures that are elements of the cytoskeleton in eukaryotic cells and posses considerable roles in cellular activities. They have higher mechanical characteristics such as superior flexibility and stiffness. In the modeling purpose of microtubules according to a hollow beam element, a novel single variable sinusoidal beam model is proposed with the conjunction of modified strain gradient theory. The advantage of this model is found in its new displacement field involving only one unknown as the Euler-Bernoulli beam theory, which is even less than the Timoshenko beam theory. The equations of motion are constructed by considering Hamilton's principle. The obtained results are validated by comparing them with those given based on higher shear deformation beam theory containing a higher number of variables. A parametric investigation is established to examine the impacts of shear deformation, length scale coefficient, aspect ratio and shear modulus ratio on dynamic and bending behaviors of microtubules. It is remarked that when length scale coefficients are almost identical of the outer diameter of MTs, microstructure-dependent behavior becomes more important.

• Journal of Yeungnam Medical Science
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• 제37권2호
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• pp.106-111
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• 2020

Background: Fever is a common cause of pediatric consultation in the emergency department. However, identifying the source of infection in many febrile infants is challenging because of insufficient presentation of signs and symptoms. Meningitis is a critical cause of fever in infants, and its diagnosis is confirmed invasively by lumbar puncture. This study aimed to evaluate potential laboratory markers for meningitis in febrile infants. Methods: We retrospectively analyzed infants aged <3 months who visited the emergency department of our hospital between May 2012 and May 2017 because of fever of unknown etiology. Clinical information and laboratory data were evaluated. Receiver operating characteristic (ROC) curves were constructed. Results: In total, 145 febrile infants aged <3 months who underwent lumbar punctures were evaluated retrospectively. The mean C-reactive protein (CRP) level was significantly higher in the meningitis group than in the non-meningitis group, whereas the mean white blood cell count or absolute neutrophil count (ANC) did not significantly differ between groups. The area under the ROC curve (AUC) for CRP was 0.779 (95% confidence interval [CI], 0.701-0.858). The AUC for the leukocyte count was 0.455 (95% CI, 0.360-0.550) and that for ANC was 0.453 (95% CI, 0.359-0.547). The CRP cut-off value of 10 mg/L was optimal for identifying possible meningitis. Conclusion: CRP has an intrinsic predictive value for meningitis in febrile infants aged <3 months. Despite its invasiveness, a lumbar puncture may be recommended to diagnose meningitis in young, febrile infants with a CRP level >10 mg/L.

• 한국육종학회지
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• 제42권1호
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.

• 한국육종학회지
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• 제40권1호
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• pp.1-7
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• 2008

An attempt was made to link rice embryo proteins to DNA sequences and to understand their functions. One hundred of the 700 spots detected on the embryo 2-DE gels were microsequenced. Of these, 28% of the embryo proteins were matched to DNA sequences with known functions, but 72% of the proteins were unknown in functions as previously reported (Woo et al. 2002). In addition, twenty-four protein spots with 100% of homology and nine with over 80% were matched to ESTs (expressed sequence tags) after expanding the amino acid sequences of the protein spots by Database searches using the available rice EST databases at the NCBI (http://www/ncbi.nlm.nih.gov/) and DDBJ (http://www.ddbj.nig.ac.jp/). The chromosomal location of some proteins were also obtained from the rice genetic map provided by Japanese Rice Genome Research Program (http://rgp.dna.affrc.go.jp). The DNA sequence databases including EST have been reported for rice (Oryza sativa L.) now provides whole or partial gene sequence, and recent advances in protein characterization allow the linking proteins to DNA sequences in the functional analysis. This work shows that proteome analysis could be a useful tool strategy to link sequence information and to functional genomics.

• Journal of Ginseng Research
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• 제43권2호
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• pp.236-241
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• 2019

Background: Thromboxane A2 ($TXA_2$) induces platelet aggregation and promotes thrombus formation. Although ginsenoside Ro (G-Ro) from Panax ginseng is known to exhibit a $Ca^{2+}-antagonistic$ antiplatelet effect, whether it inhibits $Ca^{2+}-dependent$ cytosolic phospholipase $A_2$ ($cPLA_{2{\alpha}}$) activity to prevent the release of arachidonic acid (AA), a $TXA_2$ precursor, is unknown. In this study, we attempted to identify the mechanism underlying G-Ro-mediated $TXA_2$ inhibition. Methods: We investigated whether G-Ro attenuates $TXA_2$ production and its associated molecules, such as cyclooxygenase-1 (COX-1), $TXA_2$ synthase (TXAS), $cPLA_{2{\alpha}}$, mitogen-activated protein kinases, and AA. To assay COX-1 and TXAS, we used microsomal fraction of platelets. Results: G-Ro reduced $TXA_2$ production by inhibiting AA release. It acted by decreasing the phosphorylation of $cPLA_{2{\alpha}}$, p38-mitogen-activated protein kinase, and c-Jun N-terminal kinase1, rather than by inhibiting COX-1 and TXAS in thrombin-activated human platelets. Conclusion: G-Ro inhibits AA release to attenuate $TXA_2$ production, which may counteract $TXA_2-associated$ thrombosis.

• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.500-505
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• 2019

Staphylococcus aureus is a round-shaped, gram-positive bacterium that can cause numerous infectious diseases ranging from mild infections such as skin infections and food poisoning to life-threatening infections such as sepsis, endocarditis and toxic shock syndrome. Various antibiotic-resistant strains of S. aureus have frequently emerged, threatening human lives significantly. Despite much research on the genetics of S. aureus, many of its genes remain unknown functionally and structurally. To counteract its toxins and to prevent the antibiotic resistance of S. aureus, our understanding of S. aureus should be increased at the proteomic scale. SAV0927 was first sequenced in an antibiotic resistant S. aureus strain. The gene is a conserved hypothetical protein, and its homologues appear to be restricted to Firmicutes. In this study, we determined the crystal structure of SAV0927 at $2.5{\AA}$ resolution. The protein was primarily dimeric both in solution and in the crystals. The asymmetric unit contained five dimers that are stacked linearly with ${\sim}80^{\circ}$ rotation by each dimer, and these interactions further continued in the crystal packing, resulting in a long linear polymer. The crystal structures, together with the network analysis, provide functional implications for the SAV0927-mediated protein network.

• International Journal of Oral Biology
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• 제47권3호
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• pp.33-40
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• 2022

Store-operated Ca²⁺ entry (SOCE) represents one of the major Ca²⁺ entry routes in non-excitable cells. It is involved in a variety of fundamental biological processes and the maintenance of Ca²⁺ homeostasis. The Ca²⁺ release-activated Ca²⁺ (CRAC) channel consists of stromal interaction molecule and Orai; however, the role and action of Homer proteins as an adaptor protein to SOCE-mediated Ca²⁺ signaling through the activation of CRAC channels in non-excitable cells still remain unknown. In the present study, we investigated the role of Homer2 in the process of Ca²⁺ signaling induced by the interaction between CRACs and Homer2 proteins in non-excitable cells. The response to Ca²⁺ entry by thapsigargin-mediated Ca²⁺ store depletion remarkably decreased in pancreatic acinar cells of Homer2^-/- mice, as compared to wild-type cells. It also showed critical differences in regulated patterns by the specific blockers of SOCE in pancreatic acinar cells of Homer2^-/- mice. The response to Ca²⁺ entry by the depletion in Ca²⁺ store markedly increased in the cellular overexpression of Orai1 and STIM1 as compared to the overexpression of Homer2 in cells; however, this response was remarkably inhibited by the overexpression of Orai1, STIM1, and Homer2. These results suggest that Homer2 has a critical role in the regulatory action of SOCE activity and the interactions between CRAC channels.

• Journal of Animal Science and Technology
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• 제66권1호
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• pp.204-218
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• 2024

Elsholtzia fruticosa (EF) is present in tropical regions throughout South Asian countries as well as the Himalayas. Although it has been used as a traditional medicine to treat digestive, respiratory, and inflammatory issues, its effect on preadipocyte differentiation is unknown. In this study, we examined the effects of a methanol extract prepared from EF on the differentiation of 3T3-L1 preadipocytes. Cell differentiation was assessed by microscopic observation and oil-red O staining. The expression of adipogenic and lipogenic genes, including PPARγ and C/EBPα, was measured by western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR), to provide insight into adipogenesis and lipogenesis mechanisms. The results indicated that EF promotes the differentiation of 3T3-L1 preadipocytes, with elevated lipid accumulation occurring in a concentration-dependent manner without apparent cytotoxicity. EF enhances the expression of adipogenic and lipogenic genes, including PPARγ, FABP4, adiponectin, and FAS, at the mRNA and protein levels. The effect of EF was more pronounced during the early and middle stages of 3T3-L1 cell differentiation. Treatment with EF decreased C/EBP homologous protein (CHOP) mRNA and protein levels, while increasing C/EBPα and PPARγ expression. Treatment with EF resulted in the upregulation of cyclin E and CDK2 gene expression within 24 h, followed by a decrease at 48 h, demonstrating the early-stage impact of EF. A concomitant increase in cyclin-D1 levels was observed compared with untreated cells, indicating that EF modulates lipogenic and adipogenic genes through intricate mechanisms involving CHOP and cell cycle pathways. In summary, EF induces the differentiation of 3T3-L1 preadipocytes by increasing the expression of adipogenic and lipogenic genes, possibly through CHOP and cell cycle-dependent mechanisms.