• 해부∙생물인류학
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• 제31권4호
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• pp.143-149
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• 2018

접촉피부염은 피부가 이물질과 접촉함으로써 일어나는 염증반응으로 백혈구 혈관외유출이 매우 중요한 역할을 한다는 것은 잘 알려진 사실이다. 선행연구 결과 CD99가 ${\beta}1$ 인테그린 의존적 메커니즘을 통하여 단핵구의 혈관외유출을 조절하며, 따라서 염증 질환에 대한 치료제 개발의 신규 표적 분자일 가능성이 제시되었다. 본 연구에서는 CD99 유래 펩타이드인 CD99CRIII3가 단핵구의 혈관외유출과 접촉피부염 생쥐 모델에서 염증 반응을 억제하는지를 조사하였다. 인간 단핵구 세포주인 U937를 CD99CRIII로 처리할 경우 농도의존적으로 ${\beta}1$ integrin의 활성도가 감소되었으며, 이 세포주의 사람제대정맥내피세포에의 부착과 혈관외유출도 억제되었다. 나아가 CD99CRIII3는 포르볼 미리스테이트 아세테이트 처리에 의해 유발된 생쥐 접촉피부염 모델에서 Evans Blue의 혈관투과와 귀조직 무게를 농도 의존적으로 억제하였다. 이러한 결과들은 CD99CRIII3가 단핵구의 혈관외유출과 접촉피부염 동물 모델에서 일어나는 염증반응을 억제함을 보여준다. 이와 같이, 본 연구는 CD99 유래 펩타이드가 피부 염증질환에 대한 치료제로 개발될 가능성이 있음을 제시한다.

• 한국자기공명학회논문지
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• 제24권4호
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• pp.136-142
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• 2020

Apolipoprotein B-100 (apo B-100), the main protein component that makes up LDL (Low density lipoprotein), consists of 4,536 amino acids and serves to combine with the LDL receptor. The oxidized LDL peptides by malondialdehyde (MDA) or acetylation in vivo were act as immunoglobulin (Ig) antigens and peptide groups were classified into 7 peptide groups with subsequent 20 amino acids (P1-P302). The biomimetic peptide P99 (KGTYG LSCQR DPNTG RLNGE) out of B-group peptides carrying the highest value of IgM antigens were selected for structural studies that may provide antigen specificity. Circular Dichroism (CD) spectra were measured for peptide secondary structure in the range of 190-260 nm. Experimental results show that P99 has pseudo α-helice and random coil structure. Homonuclear (COSY, TOCSY, NOESY) 2D-NMR experiments were carried out for NMR signal assignments and structure determination for P99. On the basis of these completely assigned NMR spectra and proton distance information, distance geometry (DG) and molecular dynamic (MD) were carried out to determine the structures of P99. The proposed structure was selected by comparisons between experimental NOE spectra and back-calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P99 obtained upon superposition of all atoms were in the set range. The solution state P99 has mixed structure of pseudo α-helix and β-turn(Gln[9] to Thr[13]). These NMR results are well consistent with secondary structure from experimental results of circular dichroism. Structural studies based on NMR may contribute to the prevent oxidation studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

• Molecules and Cells
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• 제39권7호
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• pp.557-565
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• 2016

The paired immunoglobulin-like type 2 receptor (PILR) family consists of two functionally opposite members, inhibitory $PILR{\alpha}$ and activating $PILR{\beta}$ receptors. PILRs are widely expressed in various immune cells and interact with their ligands, especially CD99 expressed on activated T cells, to participate in immune responses. Here we investigated whether PILR-derived agonists inhibit ${\beta}1$ integrin activity as ligands for CD99. PILR-derived peptides as well as PILR-Fc fusion proteins prevented cell adhesion to fibronectin through the regulation of ${\beta}1$ integrin activity. Especially, PILRpep3, a representative 3-mer peptide covering the conserved motifs of the PILR extracellular domain, prevented the clustering and activation of ${\beta}1$ integrin by dephosphorylating FAK and vinculin, which are major components of focal adhesion. In addition, PILRpep3 inhibited transendothelial migration of monocytes as well as endothelial cell tube formation. Furthermore, upon intraperitoneal injection of PILRpep3 into mice with collagen-induced arthritis, the inflammatory response of rheumatoid arthritis was strongly suppressed. Taken together, these results suggest that PILR-derived agonist ligands may prevent the inflammatory reactions of rheumatoid arthritis by activating CD99.