• 제목/요약/키워드: Hyperactivation

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Mechanisms of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Resistance and Strategies to Overcome Resistance in Lung Adenocarcinoma

  • Chang, Yoon Soo;Choi, Chang-Min;Lee, Jae Cheol
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.4
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    • pp.248-256
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    • 2016
  • Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance.

Changes of the Extracellular Concentrations of Striatal Dopamine and Its Metabolites by MK-801 in Morphine-Dependent Rats (MK-801 투여에 의한 몰핀의존성랫드 뇌선초체중 도파민신경절달물질의 변화)

  • 이선희;신대섭;유영아;류승렬;김대병
    • Biomolecules & Therapeutics
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    • v.6 no.1
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    • pp.25-30
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    • 1998
  • The roles of dopamine(DA) and N-methyl-D-aspartate(NMDA) system in the development and expression of morphine dependence were investigated by monitoring the concentrations of extracellular DA and its metabolites by in vivo microdialysis and simultaneous observation of behavioral changes in morphine dependent rats. Extracellular DA level in caudate putamen of morphine-dependent rat was decreased and the concentrations of its metabolites, dihydroxy phenylacetic acid(DOPAC) and homovanillic acid(HVA), were increased during naloxone-precipitated withdrawal. DA contents were recovered to normal levels by pretreatment of MK-801, a noncompetitive NMDA receptor antagonist, which may explain the mechanism of diminishing effect of MK-801 on withdrawal symptoms in morphine-dependent rats. MK-801(0.3 mg/tg, i.p.) induced the untoward hamful neurological signs such as ataxia and severe rotations, which may be produced by hyperactivation of dopaminergic system. These results suggest that MK-801 may inhibit the expression of mophine dependence by altering the dopamine release.

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The potential of Panax notoginseng against COVID-19 infection

  • Yeye Hu ;Ziliang He ;Wei Zhang ;Zhiqiang Niu ;Yanting Wang;Ji Zhang ;Ting Shen;Hong Cheng;Weicheng Hu
    • Journal of Ginseng Research
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    • v.47 no.5
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    • pp.622-626
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    • 2023
  • The COVID-19 pandemic has changed the world and has presented the scientific community with unprecedented challenges. Infection is associated with overproduction of proinflammatory cytokines secondary to hyperactivation of the innate immune response, inducing a cytokine storm and triggering multiorgan failure and significant morbidity/mortality. No specific treatment is yet available. For thousands of years, Panax notoginseng has been used to treat various infectious diseases. Experimental evidence of P. notoginseng utility in terms of alleviating the cytokine storm, especially the cascade, and improving post-COVID-19 symptoms, suggests that P. notoginseng may serve as a valuable adjunct treatment for COVID-19 infection.

Cognitive and Emotional Empathy in Young Adolescents: an fMRI Study

  • Kim, Eun Jin;Son, Jung-Woo;Park, Seong Kyoung;Chung, Seungwon;Ghim, Hei-Rhee;Lee, Seungbok;Lee, Sang-Ick;Shin, Chul-Jin;Kim, Siekyeong;Ju, Gawon;Park, Hyemi;Lee, Jeonghwan
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.31 no.3
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    • pp.121-130
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    • 2020
  • Objectives: We investigated the differences in cognitive and emotional empathic ability between adolescents and adults, and the differences of the brain activation during cognitive and emotional empathy tasks. Methods: Adolescents (aged 13-15 years, n=14) and adults (aged 19-29 years, n=17) completed a range of empathic ability questionnaires and were scanned functional magnetic resonance imaging (fMRI) during both cognitive and emotional empathy task. Differences in empathic ability and brain activation between the groups were analyzed. Results: Both cognitive and emotional empathic ability were significantly lower in the adolescent compared to the adult group. Comparing the adolescent to the adult group showed that brain activation was significantly greater in the right transverse temporal gyrus (BA 41), right insula (BA 13), right superior parietal lobule (BA 7), right precentral gyrus (BA 4), and right thalamus whilst performing emotional empathy tasks. No brain regions showed significantly greater activation in the adolescent compared to the adult group while performing cognitive empathy task. In the adolescent group, scores of the Fantasy Subscale in the Interpersonal Reactivity Index, which reflects cognitive empathic ability, negatively correlated with activity of right superior parietal lobule during emotional empathic situations (r=-0.739, p=0.006). Conclusion: These results strongly suggest that adolescents possess lower cognitive and emotional empathic abilities than adults do and require compensatory hyperactivation of the brain regions associated with emotional empathy or embodiment in emotional empathic situation. Compensatory hyperactivation in the emotional empathy-related brain areas among adolescents are likely associated with their lower cognitive empathic ability.

Effect of Korean Red Ginseng on Serum Soluble CD8 in HIV-1-Infected Patients (고려홍삼이 HIV-1 감염자에서 혈청 soluble CD8 항원 농도에 미치는 영향)

  • Cho, Young-Keol;Sung, Heung-Sup
    • Journal of Ginseng Research
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    • v.31 no.4
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    • pp.175-180
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    • 2007
  • To evaluate whether there is a relation between Korean red ginseng (KRG)-intake and the suppression of immune hyperactivation in HIV-1-infected patients, we measured serum soluble CD8 (sCD8) over 31-48 months in 168 patients. They were divided into four groups; HIV-1-infected control (n = 49), zidovudine (ZDV) group (n = 22), KRG group (n = 48), and combination of KRG and ZDV group (n = 49). In control, sCD8 and the ratio of sCD8/CD8+ T cells significantly increased by 33% (paired t-test, P < 0.05) and 54% over $21\;{\pm}\;13$ months (P < 0.001), respectively. In ZDV group, sCD8 decreased within first 6 months and then showed steady increase and the ratio also increased over $19\;{\pm}\;10$ months. In KRG group, sCD8 and the ratio of sCD/CD8+ T cells continuously decreased by 45% (P < 0.01) and 19% over $19\;{\pm}\;11$ months (P < 0.05), respectively. In combination group, sCD8 gradually decreased by 29% (P < 0.01). There was a clear difference in the changes in serum sCD8 over time among 4 groups. There was no rebound phenomenon in KRG group as shown in ZDV group. These results suggest that KRG-intake suppresses immune hyperactivation state by HIV antigen itself in the HIV-infected patients.

Inhibitory Effect of Cynaroside Isolated from Lonicera japonia Thunb on Doxorubicin-induced Necrosis in Human Renal Proximal Tubular HK-2 Cells (인동덩굴로부터 분리된 Cynaroside이 Doxorubicin으로 유도된 인간 근위세뇨관 HK-2 세포의 괴사에 미치는 저해 효과)

  • Nho, Jong Hyun;Jung, Ho Kyung;Lee, Mu Jin;Jang, Ji Hun;Sim, Mi Ok;Jung, Ja Kyun;Jung, Da Eun;An, Byeong Kwan;Cho, Hyun Woo
    • Korean Journal of Medicinal Crop Science
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    • v.25 no.5
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    • pp.322-327
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    • 2017
  • Background: Cynaroside is a flavone, a flavonoid-like compound, known by different names (luteoloside and cinaroside). It is commonly found in Lonicera japonica Thunb., Chrysanthemum moriflium, and Angelica keiskei. The process of cell death has been classified as necrosis and apoptosis. Necrosis refers to unregulated cell death induced by a chemotherapeutic agent. Doxorubicin is an anthracycline anti-cancer drug used to treat acute leukemia, cancer, and lymphoma. However, it induces nephrotoxicity including tubular damage. Therefore, we investigated the protective effect of cynaroside against doxorubicin-induced necrosis in HK-2 cells. Methods and Results: To confirm the beneficial effect of cynaroside on doxorubicin-induced necrosis, HK-2 cells, a human proximal tubule epithelial cell line were treated with $10{\mu}M$ doxorubicin and $80{\mu}M$ cynaroside. Doxorubicin treatment resulted in increased DNA fragmentation, caspase-3 activity and mitochondria hyperactivation during cell necrosis. However, pretreatment with $80{\mu}M$ cynaroside attenuated DNA fragmentation, caspase-3 activity and mitochondria hyperactivation induced by $10{\mu}M$ doxorubicin in HK-2 cells. Conclusions: These results indicated that pretreatment with cynaroside ameliorated doxorubicin-induced necrosis in HK-2 cells. Therefore, cynaroside be used as a therapeutic agent for improving doxorubicin-induced nephrotoxicity. However, further studies are required to evaluated the toxicity of cynaroside treatment in animals and to determine its protective effect against doxorubicin-induced nephrotoxicity in an animal model.

Deletion Timing of Cic Alleles during Hematopoiesis Determines the Degree of Peripheral CD4+ T Cell Activation and Proliferation

  • Guk-Yeol Park;Gil-Woo Lee;Soeun Kim;Hyebeen Hong;Jong Seok Park;Jae-Ho Cho;Yoontae Lee
    • IMMUNE NETWORK
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    • v.20 no.5
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    • pp.43.1-43.11
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    • 2020
  • Capicua (CIC) is a transcriptional repressor that regulates several developmental processes. CIC deficiency results in lymphoproliferative autoimmunity accompanied by expansion of CD44hiCD62Llo effector/memory and follicular Th cell populations. Deletion of Cic alleles in hematopoietic stem cells (Vav1-Cre-mediated knockout of Cic) causes more severe autoimmunity than that caused by the knockout of Cic in CD4+CD8+ double positive thymocytes (Cd4-Cre-mediated knockout of Cic). In this study, we compared splenic CD4+ T cell activation and proliferation between whole immune cell-specific Cic-null (Cicf/f;Vav1-Cre) and T cell-specific Cic-null (Cicf/f;Cd4-Cre) mice. Hyperactivation and hyperproliferation of CD4+ T cells were more apparent in Cicf/f;Vav1-Cre mice than in Cicf/f;Cd4-Cre mice. Cicf/f;Vav1-Cre CD4+ T cells more rapidly proliferated and secreted larger amounts of IL-2 upon TCR stimulation than did Cicf/f;Cd4-Cre CD4+ T cells, while the TCR stimulation-induced activation of the TCR signaling cascade and calcium flux were comparable between them. Mixed wild-type and Cicf/f;Vav1-Cre bone marrow chimeras also exhibited more apparent hyperactivation and hyperproliferation of Cic-deficient CD4+ T cells than did mixed wild-type and Cicf/f;Cd4-Cre bone marrow chimeras. Taken together, our data demonstrate that CIC deficiency at the beginning of T cell development endows peripheral CD4+ T cells with enhanced T cell activation and proliferative capability.

Afatinib ameliorates osteoclast differentiation and function through downregulation of RANK signaling pathways

  • Ihn, Hye Jung;Kim, Ju Ang;Bae, Yong Chul;Shin, Hong-In;Baek, Moon-Chang;Park, Eui Kyun
    • BMB Reports
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    • v.50 no.3
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    • pp.150-155
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    • 2017
  • Non-small-cell lung cancer (NSCLC) is the third most common cancer that spreads to the bone, resulting in osteolytic lesions caused by hyperactivation of osteoclasts. Activating mutations in epidermal growth factor receptor-tyrosine kinase (EGF-TK) are frequently associated with NSCLC, and afatinib is a first-line therapeutic drug, irreversibly targeting EGF-TK. However, the effects of afatinib on osteoclast differentiation and activation as well as the underlying mechanism remain unclear. In this study, afatinib significantly suppressed receptor activator of nuclear factor ${\kappa}B$ (RANK) ligand (RANKL)-induced osteoclast formation in bone marrow macrophages (BMMs). Consistently, afatinib inhibited the expression of osteoclast marker genes, whereas, it upregulated the expression of negative modulator genes. The bone resorbing activity of osteoclasts was also abrogated by afatinib. In addition, afatinib significantly inhibited RANKL-mediated Akt/protein kinase B and c-Jun N-terminal kinase phosphorylation. These results suggest that afatinib substantially suppresses osteoclastogenesis by downregulating RANK signaling pathways, and thus may reduce osteolysis after bone metastasis.

Mechanistic Target of Rapamycin Pathway in Epileptic Disorders

  • Kim, Jang Keun;Lee, Jeong Ho
    • Journal of Korean Neurosurgical Society
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    • v.62 no.3
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    • pp.272-287
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    • 2019
  • The mechanistic target of rapamycin (mTOR) pathway coordinates the metabolic activity of eukaryotic cells through environmental signals, including nutrients, energy, growth factors, and oxygen. In the nervous system, the mTOR pathway regulates fundamental biological processes associated with neural development and neurodegeneration. Intriguingly, genes that constitute the mTOR pathway have been found to be germline and somatic mutation from patients with various epileptic disorders. Hyperactivation of the mTOR pathway due to said mutations has garnered increasing attention as culprits of these conditions : somatic mutations, in particular, in epileptic foci have recently been identified as a major genetic cause of intractable focal epilepsy, such as focal cortical dysplasia. Meanwhile, epilepsy models with aberrant activation of the mTOR pathway have helped elucidate the role of the mTOR pathway in epileptogenesis, and evidence from epilepsy models of human mutations recapitulating the features of epileptic patients has indicated that mTOR inhibitors may be of use in treating epilepsy associated with mutations in mTOR pathway genes. Here, we review recent advances in the molecular and genetic understanding of mTOR signaling in epileptic disorders. In particular, we focus on the development of and limitations to therapies targeting the mTOR pathway to treat epileptic seizures. We also discuss future perspectives on mTOR inhibition therapies and special diagnostic methods for intractable epilepsies caused by brain somatic mutations.

Antioxidant effect of Lonicera Caerulea on heat stress-treated male mice

  • Kang, Donghun;Kim, Daeyoung
    • Journal of Animal Reproduction and Biotechnology
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    • v.36 no.4
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    • pp.220-229
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    • 2021
  • Lonicera caerulea (Honey berry, HB) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti-oxidant. however, it is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm's maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, the purpose of this study is to investigate the antioxidant effects of L. Caerulea on the sperm and mice. At first, it conducted using ICR mouse (n = 20) for 4 weeks. There are four groups of mice (n = 5 per group). Also, L. Caerulea was taken by oral gavage. Group I (control) kept at 23℃-27℃ and administer D.W (0.5 mL/day), Likewise, Group II (HB) kept at room temperature but gave HB (250 mg/kg, 0.5 mL/day), Group III (HB + HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group IV (HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real-time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L. Caerulea.