• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3405-3409
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• 2016

Malignant pleural mesothelioma (MPM), an aggressive malignant tumor of mesothelial origin associated with asbestos exposure, shows a limited response to conventional chemotherapy and radiotherapy. Therefore, the overall survival of MPM patients remains very poor. Progress in the development of therapeutic strategies for MPM has been limited. We recently reported that the calpain inhibitor, calpeptin exerted inhibitory effects on pulmonary fibrosis by inhibiting the proliferation of lung fibroblasts. In the present study, we examined the preventive effects of calpeptin on the cell growth of MPM, the origin of which is mesenchymal cells, similar to lung fibroblasts. Calpeptin inhibited the proliferation of MPM cells, but not mesothelial cells. It also prevented 1) the expression of angiopoietin (Ang)-1 and Tie-2 mRNA in MPM cells, but not mesothelial cells and 2) the Ang-1-induced proliferation of MPM cells through an NF-kB dependent pathway, which may be the mechanism underlying the preventive effects of calpeptin on the growth of MPM cells. These results suggest potential clinical use of calpeptin for the treatment of MPM.

• 한국동물학회지
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• 제36권3호
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• pp.342-346
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• 1993

배양 근원세포의 세포 골격 단백질의 양이 분화과정에 따라 점차 감소하는 것으로 나타났다. 이러한 세포 골격 단백질의 분해는, 세포막에 투과성을 나타내는 calpain의 저해제인 calpeptin의 처리에 의하여 억제될 수 있었다. 또한, calpeptin은 특정 세포 골격 단백질의 분해를 제한적으로 억제하였으나, 전체적인 세포 단백질의 양상에는 별 영향을 주지 않았다. 뿐만 아니라, calpeptin은 농도 의존적으로 근원세포의 융합을 억제하였다. 반면에, calpain의 강력한 저해제이지만 세포막에 투과성을 보이지 않는 E-64는 세포 골격 단백질의 분해와 막 융합에 아무런 효과를 나타내지 못하였다. 이러한 결과는 calpain이 근세포 분화 시기에 따라 세포 골격 단백질의 분해를 촉매하며, 이 분해 과정은 근원세포 융합에 필연적인 것으로 추측된다. 또한, 이 결과는 calpain 저해제들의 선별적 효과가 그들의 세포막에 대한 투과성에 기인함을 시사한다.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.459-469
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• 2014

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-${\kappa}B$ (p65) in Caco-2 cells. However, $I{\kappa}B$, an inhibitor of NF-${\kappa}B$, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-${\kappa}B$ was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-${\kappa}B$ and STATs in colonic epithelial cells, which ultimately accelerates cell death.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.67-67
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• 2003

Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, activation of caspase-2, 3, 8, and 9 was evident within 2 8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.

• Parasites, Hosts and Diseases
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• 제49권2호
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• pp.177-180
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• 2011

Entamoeba histolytica is an enteric tissue-invading protozoan parasite that can cause amebic colitis and liver abscess in humans. E. histolytica has the capability to kill colon epithelial cells in vitro; however, information regarding the role of calpain in colon cell death induced by ameba is limited. In this study, we investigated whether calpains are involved in the E. histolytica-induced cell death of HT-29 colonic epithelial cells. When HT-29 cells were co-incubated with E. histolytica, the propidium iodide stained dead cells markedly increased compared to that in HT-29 cells incubated with medium alone. This pro-death effect induced by ameba was effectively blocked by pretreatment of HT-29 cells with the calpain inhibitor, calpeptin. Moreover, knockdown of m- and ${\mu}$-calpain by siRNA significantly reduced E. histolytica-induced HT-29 cell death. These results suggest that m- and ${\mu}$-calpain may be involved in colon epithelial cell death induced by E. histolytica.

• Parasites, Hosts and Diseases
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• 제51권3호
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• pp.279-287
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• 2013

Autophagy is a process of cytoplasmic degradation of endogenous proteins and organelles. Although its primary role is protective, it can also contribute to cell death. Recently, autophagy was found to play a role in the activation of host defense against intracellular pathogens. The aims of our study was to investigate whether host cell autophagy influences Toxoplasma gondii proliferation and whether autophagy inhibitors modulate cell survival. HeLa cells were infected with T. gondii with and without rapamycin treatment to induce autophagy. Lactate dehydrogenase assays showed that cell death was extensive at 36-48 hr after infection in cells treated with T. gondii with or without rapamycin. The autophagic markers, LC3 II and Beclin 1, were strongly expressed at 18-24 hr after exposure as shown by Western blotting and RT-PCR. However, the subsequent T. gondii proliferation suppressed autophagy at 36 hr post-infection. Pre-treatment with the autophagy inhibitor, 3-methyladenine (3-MA), down-regulated LC3 II and Beclin 1. The latter was also down-regulated by calpeptin, a calpain inhibitor. Monodansyl cadaverine (MDC) staining detected numerous autophagic vacuoles (AVs) at 18 hr post-infection. Ultrastructural observations showed T. gondii proliferation in parasitophorous vacuoles (PVs) coinciding with a decline in the numbers of AVs by 18 hr. FACS analysis failed to confirm the presence of cell apoptosis after exposure to T. gondii and rapamycin. We concluded that T. gondii proliferation may inhibit host cell autophagy and has an impact on cell survival.