• Title/Summary/Keyword: apoptosis event

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Suppression of Monosodium Urate-induced NLRP3 Inflammasome Activation by Garlic-derived Sulfur-containing Phytochemicals is Associated with Blocking ROS Generation in RAW 264.7 Macrophages (RAW 264.7 대식세포에서 마늘 유래 황 함유 화합물에 의한 요산 유도 inflammasome 활성화의 억제는 ROS 생성 차단과 연관성이 있음)

  • Min Yeong Kim;Yung Hyun Choi
    • Journal of Life Science
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    • v.33 no.4
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    • pp.349-356
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    • 2023
  • Gout, a chronic inflammatory arthritic disease, is characterized by hyperuricemia. Gout can be induced by an inflammatory response to monosodium urate (MSU) crystals mediated by pro-inflammatory cytokine release following activation of the NOD-like receptor protein 3 (NLRP3) inflammasome. Many sulfur-containing phytochemical compounds in garlic (Allium sativum L.) are considered active ingredients because of their potential pharmacological benefits for various diseases, but their efficacy in NLRP3 inflammasome activation-mediated gout has not been demonstrated. In this study, we investigated whether diallyl disulfide (DADS) and diallyl trisulfide (DATS), representative garlic-derived sulfur compounds, have an inhibitory effect on MSU-induced NLRP3 inflammasome activation. Our results showed that under non-cytotoxic conditions, DADS and DATS significantly blocked nitric oxide production and interleukin (IL)-1β release in response to MSU in lipopolysaccharide (LPS)-primed RAW 264.7 macrophages. DADS and DATS also attenuated enhanced expression of NLRP3 and its adapter protein, apoptosis-associated speck-like protein, which was associated with downregulation of and caspase-1 p20 and IL-1β expression, suggesting that MSU-induced LRP3 inflammasome activation was counteracted by DADS and DATS. Furthermore, DADS and DATS blocked oxidative stress, an upstream event for NLRP3 inflammasome activation, as evidenced by the fact that they scavenged reactive oxygen species (ROS) production. Taken together, our findings demonstrate that DADS and DATS suppressed NLRP3 inflammasome activation by inhibiting the ROS/NLRP3 pathway and that they have potential as treatments for NLRP3-dependent gouty arthritis.

Expression of Jun and p53 Genes from the Brain of Rats Irradiated with $^{60}Co{\gamma}$-ray (감마선 조사에 의한 뇌조직의 Jun 및 p53유전자 발현)

  • Kim Yong Seok;Woo Chong Kyu;Lee Yong Sung;Koh Jai Kyung;Chun Ha Chung;Lee Myung Za
    • Radiation Oncology Journal
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    • v.14 no.4
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    • pp.265-279
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    • 1996
  • Damage produced by radiation elicits a complex response in mammalian cells, including growth rate changes and the induction of a variety of genes associated with growth control and apoptosis. At doses of 10,000 cGy or greater, the exposed individual was killed in a matter of minutes to a couple of days, with symptoms consistent with pathology of the central nervous system(CNS) including degenerative changes. The nature of the damage in irradiated cells underlies the unique hazards of ionizing radiation. Radiation injury to CNS is a rare event in clinical medicine, but it is catastrophic for the patient in whom it occurs. The incidence of cerebral necrosis has been reported as high as 16% for doses greater than 6,000 cGy. In this study, the effect of radiation on brain tissue was studied in vivo. Jun and p53 genes in the rat brain were induced by whole body irradiation of rat with 600Co in doses between 1 Gy and 100 Gy and analyzed for expression of jun and p53 genes at the postirradiation time up to 6 hours. Northern analyses were done using 1.8 Kb & 0.8 Kb-pGEM-2-JUN/Eco RI/Pst I fragments, 2.0 Kb-php53B/Bam HI fragment and ,1.1 Kb-pBluescript SK--ACTIN/Eco RI fragment as the digoxigenin or [${\alpha}^{32}P$] dCTPlabeled probes for Jun, p53 and ${\beta}$-actin genes, respectively. Jun gene seemed to be expressed near the threshold levels in 1 hour after irradiation of $^{60}$Co in dose less than 1 Gy and was expressed in maximum at 1 hour after irradiation of $^{60}$Co in dose of 30 Gy. Jun was expressed increasingly with time until 5 or 6 hours after irradiation of $^{60}$Co in doses of 1 Gy and 10 Gy. After irradiation of $^{60}$Co in dose between 20 Gr and 100 Gy, the expression of Jun was however increased to peak in 2 hours and decreased thereafter. p53 gene in this study also seemed to be expressed near the threshold levels in 1 hour after irradiation of $^{60}$Co in dose less than 1 Gy and was expressed in maximum at 6 hours after irradiation of $^{60}$Co in dose of 1 Gy, p53 was expressed increasingly with time until 5 or 6 hours after irradiation of $^{60}$Co in dose between 1 Gy and 40 Gy. After irradiation of $^{60}$Co in doses of 50 Gy and 100 Gy, the expression of p53 was however increased to peak in 2 hours and decreased thereafter. The expression of Jun and p53 genes was not correlative in the brain tissue from rats. It seemed to be very important for the establishment of the optimum conditions for the animal studies relevant to the responses of genes inducible on DNA damage to ionizing radiation in mammalian cells. But there are many limitations to the animal studies such as the ununiform patterns of gene expression from the tissue because of its complex compositions. It is necessary to overcome the limitations for development of in situ Northern analysis.

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STUDY ON MUTATION OF P53 AND EXPRESSION OF MDM-2 IN DMBA INDUCED CARCINOMA OF HAMSTER BUCCAL POUCH (DMBA로 유도된 햄스터 협낭암종에서 p53 유전자 변이와 mdm-2 단백의 발현에 관한 연구)

  • Park, Yong-Sun;Kim, Kyung-Wook;Lee, Jae-Hoon;Kim, Chang-Jin
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.5
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    • pp.373-384
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    • 2001
  • Cellular proliferation is an intricately regulated process mediated by the coordinated interactions of critical growth control genes. Two of these factors in mammalian cells are the p53 and mdm-2 genes. A protein product of the mem-2 oncogene has been recently shown to associate with the protein encoded by the tumor suppressor gene p53. The p53 tumor suppressor protein is stabilized in response to DNA damage and other stress signals and causes the cell to undergo growth arrest or apoptosis, thus preventing the establishment of mutations in future cellular generations. Mutation or loss of p53 is a very common event in tumor progression. It occurs in about 50% of all tumors analysed including of colon, lung, breast and liver. The cellular mdm-2 gene, which has potential transforming activity that can be activated by overexpression, is amplified in a significant percentage of human sarcoma and in other mammalian tumors. Proteins encoded by the mdm-2 gene are able to bind to the p53 protein and, when overexpressed, can inhibit p53's transcriptional activation function, thus mdm-2 can act as a negative regulator of p53 function. Experimental study was performed to observe the relationship between p53 gene mutation and mdm-2 protein expression and apply the results to the clinical activity. 36 golden syrian hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek(control side) was treated with mineral oil as the same manner to the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were examined for histology and immunohistochemistry observation, and were completely dissected by microdissection and DNA from both tissue were isolated by proteins K/phenol/chloroform extraction. Segments of the hamster p53 exons 5, 6, 7 and 8 were amplified by PCR using the oligonucleotide primers, and then confirmational change was observed by SSCP respectively. The results were as follows : 1. Dysplasia at 6 weeks, carcinoma in situ at 8 weeks and invasive carcinoma from 10 weeks could be observed in experimental groups. 2. p53 mutations were detected in 10 of the 36(28%) and the exons 6(6 of the 10 : 60%) was the most hot spot area among the highy conserved region(exons 5, 6, 7 & 8). 3. Immunohistochemical study confirmed 22 of the 36(61%) of p53 expression involving 10 of p53 mutations. 4. mdm-2 expression of was showed in 3 of the 36(8%) involving 1 of the 22 of p53 expression and 2 of the 14 of p53 non-expression. From the above results, mutation of p53 gene or expression of p53 protein may have the influence of the DMBA induced carcinoma of hamster buccal pouch but the expression of mdm-2 protein may not have relationship with tumorigenesis.

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Expression Pattern of KLF4 in Korean Gastric Cancers (한국인 위암에서 KLF4 단백 발현 양상)

  • Song, Jae-Hwi;Cho, Yong-Gu;Kim, Chang-Jae;Park, Cho-Hyun;Kim, Su-Young;Nam, Suk-Woo;Lee, Sug-Hyung;Yoo, Nam-Jin;Lee, Jung-Young;Park, Won-Sang
    • Journal of Gastric Cancer
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    • v.5 no.3 s.19
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    • pp.200-205
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    • 2005
  • Purpose: KLF4, a member of the KLF family, is a zinc finger tumor suppressor protein that is critical for gastric epithelial homeostasis. Our aim was to determine whether the altered expression of KLF4 might be associated with gastric cancer development and, if so, to determine to which pathologic parameter it is linked. Materials and Methods: For the construction of the gastric cancer tissue microarray, 84 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression pattern of KLF4 was examined on tissue microarray slides by using immunohistochemistry and was compared with pathologic parameters, including histologic type, depth of invasion, lymph node metastasis, and peritoneal dissemination. Results: The KLF4 protein was expressed in cytoplasm and nucleus of superficial and foveolar epithelial cells in the normal gastric mucosa. We found markedly reduced or loss of KLF4 expression in 43 (51.2%) of the 84 gastric cancer tissues. There was no significant correlation between KLF4 expression and pathologic parameters, including histologic type, depth of invasion, lymph node metastasis and peritoneal dissemination. Conclusion: Our findings suggest that altered expression of KLF4 may contribute to abnormal regulation of gastrointestinal epithelial cell growth and differentiation and to the development of Korean gastric cancer, as an early event.

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