• Title/Summary/Keyword: Cyclic peptide

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Selective Inhibition of Bicyclic Tetrapeptide Histone Deacetylase Inhibitor on HDAC4 and K562 Leukemia Cell

  • Li, Xiao-Hui;Huang, Mei-Ling;Wang, Shi-Miao;Wang, Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7095-7100
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    • 2013
  • Histone deacetylase (HDAC) inhibitors of cyclic peptide have been proved to be the most complex but the most stable and relative efficient inhibitors because of their large cap region. In this paper, a series of studies were carried out to evaluate the efficacy of synthetic bicyclic tetrapeptide inhibitors 1-5 containing hydroxamic acid referring molecular docking, anti-proliferation, morphology and apoptosis. Docking analysis, together with enzyme inhibitory results, verified the selective capability of inhibitor 4 to HDAC4, which might closely related to haematological tumorigenesis, with Phe227, Asp115, Pro32, His198 and Ser114 participating into hydrophobic interactions and Van der Waals force which was familiar with former study. Moreover, inhibitor 4 inhibited K562 cell line at the $IC_{50}$ value of 1.22 ${\mu}M$ which was 51-67 times more efficient than that for U937 and HL60 cell lines. Inhibitor 4 exhibited the cell cycle-arrested capability to leukemia at S phase or G2/M phase as well as apoptosis-induced ability in different degrees. Finally, we considered that bicyclic tetrapeptide inhibitors were promising inhibitors used in cancer treatment and inhibitor 4 could prevent K562 cell line well from proliferation, arrest cell cycle and induce K562 towards apoptosis to achieve the goals of reversing cancer cells which could become a potential leukemia therapeutic agent in the future.

Thymic Stromal Lymphopoietin (TSLP) Gene Polymorphisms are not Associated with Rheumatoid Arthritis in a Korean Population (TSLP 유전자의 다형성은 한국인 류마티스관절염 발생에 영향을 미치치 않는다)

  • Lee, Sam-Youn;Yu, Ji-In;Chae, Soo-Cheon
    • Journal of Life Science
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    • v.22 no.1
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    • pp.25-30
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    • 2012
  • Thymic stromal lymphopoietin(TSLP) is a novel IL-7-like hematopoietic cytokine. Human TSLP is produced by epithelial cells, stromal cells, and mast cells. The TSLP gene is highly expressed in synovial fluid specimens derived from rheumatoid arthritis (RA) patients. We previously identified four single nucleotide polymorphisms (SNPs) and one variation site in human TSLP gene. In this study, we analyzed the genotypic and allelic frequencies of the TSLP SNPs between RA patients and healthy controls. We also investigated the relationships between SNP genotypes and the RF levels and anti-synthetic cyclic citrullinated peptide (CCP) levels in RA patients. We then calculated the haplotype frequencies defined by these SNPs for both groups. The genotype and allele frequencies of the TSLP SNPs did not differ significantly between the RA patients and the healthy controls. We also found that TSLP SNPs in the RA patients had no significant association with the levels of RF or anti-CCP. Our results suggest that TSLP SNPs are not associated with susceptibility to RA.

Structure-Antagonistic Activity Relationships of an NK-2 Tachykinin Receptor Antagonist, L-659,877 and Its Analogues

  • Ha, Jong-Myung;Shin, Song-Yub;Hong, Hea-Nam;Suh, Duk-Joon;Jang, Tae-Sik;Kang, Shin-Won;Kuean, Sun-Jin;Ha, Bae-Jin
    • BMB Reports
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    • v.29 no.5
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    • pp.429-435
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    • 1996
  • To investigate the structure-antagonistic relationship of the cyclohexapeptide L-659,877, a selective NK-2 tachykinin receptor antagonist, seven analogues were chemically synthesized by a solid phase method. The agonistic and antagonistic activities of the analogues were evaluated by contraction assay using the smooth muscle of guinea pig trachea (GPT) containing the NK-2 receptor. It was shown that the aromatic ring of Phe at position 3 and the sulfur group of Met at position 6 in L-659,877 were essential for binding to the NK-2 receptor. Decrease in antagonistic activity of L-659,877 caused by substituting Leu for Nle at position 5 indicates that the ${\gamma}$ methyl group and side chain length of Leu plays an important role in its antagonistic action. Although the activity was slightly lower than L-659,877, cyclo $[{\beta}Ala^{8}]NKA(4-10)$ (analogue 1) showed potential antagonistic activity for the NK-2 receptor. It was confirmed that the expansion of the ring in L-659,877 by substitution of ${\beta}Ala$ for Gly at position 4 stabilized its conformation monitored by CD spectra. The results suggest that analogue 1 can be used as a new leader compound to design a more powerful, selective, and stable NK-2 receptor antagonist.

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An overlap syndrome of Churg-Strauss syndrome and rheumatoid arthritis

  • Bae, Seung Il;Jang, Jong Geol;Kim, Hun Tae;Ahn, Hee Yun;Kim, Min Jung;Kim, Hyun Je;Lee, Choong Ki;Hong, Young Hoon
    • Journal of Yeungnam Medical Science
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    • v.32 no.2
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    • pp.127-131
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    • 2015
  • Churg-Strauss syndrome (CSS) is a necrotizing vasculitis with extra-, peri-vascular eosinophilic infiltration. Chronic symmetric polyarthritis with the presence of rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody are the mainstay of rheumatoid arthritis (RA) diagnosis. Mononeuritis multiplex is a peripheral neuropathy involving more than 2 separate nerve areas. A 62-year-old male patient was referred for left foot drop and polyarthritis of both hands and feet for 4 months. During evaluation, mononeuritis multiplex was detected on nerve conduction study and electromyography tests: vasculitis with neutrophil, eosinophil, and lymphocyte infiltration on peroneal nerve biopsy. A positive response to methacholin and bronchodilator was observed on the pulmonary function test. Radiologic tests showed peri-articular soft tissue swelling and osteopenia on both hand and foot. Marked peripheral eosinophilia, high RF, and positive perinuclear anti-neutrophil cytoplasmic antibody were detected on blood tests. Here, we report on a patient with overlap syndrome of CSS and RA with review of the relevant literature, from which a few references to overlap syndrome of CSS and RA were available.

YH18968, a Novel 1,2,4-Triazolone G-Protein Coupled Receptor 119 Agonist for the Treatment of Type 2 Diabetes Mellitus

  • Han, Taedong;Lee, Byoung Moon;Park, Yoo Hoi;Lee, Dong Hoon;Choi, Hyun Ho;Lee, Taehoon;Kim, Hakwon
    • Biomolecules & Therapeutics
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    • v.26 no.2
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    • pp.201-209
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    • 2018
  • G protein-coupled receptor 119 (GPR119) is expressed in the pancreas and gastrointestinal tract, and its activation promotes insulin secretion in the beta cells of the pancreatic islets as well as the secretion of glucagon-like peptide-1 (GLP-1) in intestinal L cells, consequently improving glucose-stimulated insulin secretion. Due to this dual mechanism of action, the development of small-molecule GPR119 agonists has received significant interest for the treatment of type 2 diabetes. We newly synthesized 1,2,4-triazolone derivatives of GPR119 agonists, which demonstrated excellent outcomes in a cyclic adenosine monophosphate (cAMP) assay. Among the synthesized derivatives, YH18968 showed cAMP=2.8 nM; in GLUTag cell, GLP-1secretion=2.3 fold; in the HIT-T15 cell, and insulin secretion=1.9 fold. Single oral administration of YH18968 improved glucose tolerance and combined treatment with a dipeptidyl peptidase 4 (DPP-4) inhibitor augmented the glucose lowering effect as well as the plasma level of active GLP-1 in normal mice. Single oral administration of YH18968 improved glucose tolerance in a diet induced obese mice model. This effect was maintained after repeated dosing for 4 weeks. The results indicate that YH18968 combined with a DPP-4 inhibitor may be an effective therapeutic candidate for the treatment of type 2 diabetes.

Association of Thymic Stromal Lymphopoietin Receptor (TSLPR) Polymorphisms with the Susceptibility of Rheumatoid Arthritis in a Korean Population (한국인 류마티스 관절염의 감수성과 TSLPR 유전자 다형성의 연관성)

  • Yu, Ji-In;Mo, Ji-Su;Chae, Soo-Cheon
    • Journal of Life Science
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    • v.23 no.7
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    • pp.919-925
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    • 2013
  • Human thymic stromal lymphopoietin receptor (TSLPR) might play an important role in the development of inflammatory and allergic responses. We previously identified eleven single nucleotide polymorphisms (SNPs) and two variation sites in the TSLPR gene and showed that all the SNPs of the TSLPR gene are associated with susceptibility to atopic asthma. The present study aimed to investigate whether the TSLPR gene SNPs are associated with susceptibility to rheumatoid arthritis (RA). We compared the genotype and the allele frequencies of the TSLPR SNPs in 457 RA patients and 570 healthy controls. The genotype and the allele frequencies of the TSLPR gene SNPs in the RA patients were not significantly different from the respective frequencies of the healthy controls. Additional analysis showed that the genotype and the allele frequencies of the TSLPR gene SNPs did not appear to be associated with RA in female RA patients. The TSLPR gene SNPs in the RA patients did not affect the production of rheumatoid factor (RF) and antisynthetic cyclic citrullinated peptide (CCP). Our results suggest that the TSLPR gene SNPs are not associated with susceptibility to RA in the Korean population.

Meta-Analysis of Effect in Serum Bio-Markers for Early Diagnosis: Rheumatoid Arthritis

  • Woo, Myoung Soo;Mun, Sora;Kang, Hee-Gyoo
    • Biomedical Science Letters
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    • v.27 no.4
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    • pp.298-309
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    • 2021
  • Rheumatoid arthritis refers to acute and chronic arthritis due to unexplained autoantibody attack. Rheumatoid arthritis should be accompanied by difficulty in mobility and severe distress due to the progression of systemic arthritis. Therefore, this study early diagnoses the effects of Rheumatoid factor (RF), C-reactive protein (CRP), and Anti-cyclic citrullinated peptide (Anti-CCP), which are typical serum markers for rheumatoid arthritis by meta-analysis. Pubmed and EMBASE, were used as PICO criteria, and two independent researchers selected papers according to the criteria set in this study. The selection criteria was a study of patients with rheumatoid arthritis who developed early onset, and the paper was evaluated using the NCS. Forest plot and Funnel plot graphs for each serum marker were calculated using Revman 5.4. After finding 193 papers on Pubmed and 184 papers on EMBASE and selecting according to the criteria, a total of 41 papers were used for the analysis. The magnitude of the effect that appears in the Forest plot of RF with the Mean differnce value is 134.34, CRP is 21.42 and Anti-CCP is 270.41. The magnitude of the effect of Anti-CCP in meta-analysis was analyzed to be larger than that of RF and CRP, and it is considered that the development of early-diagnosis serum markers using Anti-CCP and additional retrospective studies are highly effective. The combination of RF, CRP, and Anti-CCP as a panel marker is expected to be very efficient.

Evolutionary Explanation for Beauveria bassiana Being a Potent Biological Control Agent Against Agricultural Pests

  • Han, Jae-Gu
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.27-28
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    • 2014
  • Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

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Pharmacological Action Mechanism(s) of Vasodilator Effect of Calcitonin Gene-related Peptide in Rat Basilar Arteries (흰쥐의 뇌 기저동맥에서 CGRP에 의한 혈관 이완반응의 기전에 대한 연구)

  • Rhim, Byung-Yong;Hong, Sun-Hwa;Kim, Chi-Dae;Lee, Won-Suk;Kim, Dong-Heon;Hong, Ki-Whan
    • The Korean Journal of Pharmacology
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    • v.32 no.1
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    • pp.39-49
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    • 1996
  • In the present study, we observed change in intracellular $Ca^{2+}$$([Ca^{2+}]_i)$ as measured with the fluorescent $Ca^{2+}-indicator$ fura-2 in association with force development of the rat basilar arteries during activation by$K^+$ depolarizing solution and U46619, a thromboxane analogue, in the absence and the presence of calcitonin-gent related peptide (CGRP). CGRP (30 and 100 nM) caused a concentration-dependent inhibition of U46619-induced contraction with decrease in $[Ca^{2+}]_i$, whereas it did not exert any effect on the $K^+$ (90 mM)-induced contraction and increase in $[Ca^{2+}]_i$, Further, $[Ca^{2+}]_i-force$ relationships were determined by plotting the ratio of $F_{340}/F_{380}$ $([Ca^{2+}]_i)$ as a function of the force induced by U46619, and the results were compared with those obtained in the presence of CGRP. The curves obtained in the presence of CGRP (30 and 100 nM) were significantly moved to downward without right shift of the curves suggesting that CGRP inhibited the U46619-induced contraction only by mediation of reduction in $[Ca^{2+}]_i$ with out any change in the sensitivity of contractile apparatus to $Ca^{2+}$. The CGRP-induced attenuation of $[Ca^{2+}]_i$ and force development was significantly inhibited under pretreatment with CGRP $(8{\sim}37)$ fragment (100 nM), a CGRP1 receptor antagonist. Both the reduced contraction and reduction in $[Ca^{2+}]_i$ caused by CGRP were fully reversed by pretreatment with charybdotoxin (100 nM) and iberiotoxin (100 nM), large conductance $Ca^{2+}-activated$ $K^+$ channel blockers, but not by apamin (300 nM), a small conductance $Ca^{2+}-activated$ $K^+$ channel blocker, and glibenclamide ( 1 ${\mu}M$), an ATP-sensitive $K^+$ channel blocker. In conclusion, it is suggested that the CGRP1 receptor, upon activation by CGRP, are coupled to opening of $Ca^{2+}-activated$ $K^+$ channel and cause to decrease in $[Ca^{2+}]_i$, thereby leading to vasodilation of the rat basilar artery. However, it is not defined that the mechanism underlying vasodilation whether the $K^+$ channel blockers, charybdotoxin and iberiotoxin directly block the CGRP receptors and that CGRP-evoked relaxation is dependent on the cyclic AMP or $K^+$ channel opening or both actions.

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Gene Expression Profiles in Cervical Cancer with Radiation Therapy Alone and Chemo-radiation Therapy (자궁경부암의 방사선치료 및 방사선항암화학 병용치료에 따른 유전자발현 조절양상)

  • Lee Kyu Chan;Kim Meyoung-kon;Kim Jooyoung;Hwang You Jin;Choi Myung Sun;Kim Chul Yong
    • Radiation Oncology Journal
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    • v.21 no.1
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    • pp.54-65
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    • 2003
  • Purpose : To analyze the gene expression Profiles of uterine ceulcal cancer, and its variation after radiation therapy, with or without concurrent chemotherapy, using a CDNA microarray. Materials and Methods :Sixteen patients, 8 with squamous ceil carcinomas of the uterine cervix, who were treated with radiation alone, and the other 8 treated w14h concurrent chemo-radiation, were Included in the study. Before the starling of the treatment, tumor biopsies were carried out, and the second time biopsies were peformed after a radiation dose of 16.2$\~$27 Gy. Three normal cervix tissues were used as a control group. The microarray experiments were peformed with 5 groups of the total RNAs extracted individually and then admixed as control, pre-radiation therapy alone, during-radiation therapy alone, pre-chemoradiation therapy, and during-chemoradlation therapy. The 33P-iabeled CDNAS were synthesized from the total RNAs of each group, by reverse transcription, and then they were hybridized to the CDNA microarray membrane. The gene expression of each microarrays was captured by the intensity of each spot produced by the radioactive isotopes. The pixels per spot were counted with an Arrayguage, and were exported to Microsoft Excel The data were normalized by the Z transformation, and the comparisons were peformed on the Z-ratio values calculated. Results : The expressions of 15 genes, including integrin linked kinase (ILK), CDC28 protein kinase 2, Spry 2, and ERK 3, were increased with the Z-ratio values of over 2.0 for the cervix cancer tissues compared to those for the normal controls. Those genes were involved In cell growth and proliferation, cell cycle control, or signal transduction. The expressions of the other 6 genes, Including G protein coupled receptor kinase 5, were decreased with the Z-ratio values of below -2.0. After the radiation thorapy, most of the genes, with a previously Increase expressions, represented the decreased expression profiles, and the genes, with the Z-ratio values of over 2.0, were cyclic nucleotlde gated channel and 3 Expressed sequence tags (EST). In the concurrent chemo-radiation group, the genes involved in cell growth and proliferation, cell cycle control, and signal transduction were shown to have increased expressions compared to the radiation therapy alone group. The expressions of genes involved in anglogenesis (angiopoietln-2), immune reactions (formyl peptide receptor-iike 1), and DNA repair (CAMP phosphodiesterase) were increased, however, the expression of gene involved In apoptosls (death associated protein kinase) was decreased. Conclusion : The different kinds of genes involved in the development and progression of cervical cancer were identified with the CDNA microarray, and the proposed theory is that the proliferation signal stalls with ILK, and is amplified with Spry 2 and MAPK signaling, and the cellular mitoses are Increased with the increased expression oi Cdc 2 and cell division kinases. After the radiation therapy, the expression profiles demonstrated 4he evidence of the decreased cancer cell proliferation. There was no sigificant difference in the morphological findings of cell death between the radiation therapy aione and the chemo-radiation groups In the second time biopsy specimen, however, the gene expression profiles were markedly different, and the mechanism at the molecular level needs further study.