• Biomolecules & Therapeutics
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• 제31권1호
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• pp.59-67
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• 2023

Thrombin is a serine protease that participates in a variety of biological signaling through protease-activated receptors. Intestinal myofibroblasts play central roles in maintaining intestinal homeostasis. In this study, we found that thrombin-induced apoptosis is mediated by the calcium-mediated activation of cytosolic phospholipase A₂ in the CCD-18Co cell. Thrombin reduced cell viability by inducing apoptosis and proteinase-activated receptor-1 antagonist attenuated thrombin-induced cell death. Endogenous ceramide did not affect the cell viability itself, but a ceramide-mediated pathway was involved in thrombin-induced cell death. Thrombin increased intracellular calcium levels and cytosolic phospholipase A₂ activity. The ceramide synthase inhibitor Fumonisin B1, intracellular calcium chelator BAPTA-AM, and cytosolic phospholipase A₂ inhibitor AACOCF₃ inhibited thrombin-induced cell death. Thrombin stimulated arachidonic acid release and reactive oxygen species generation, which was blocked by AACOCF₃, BAPTA-AM, and the antioxidant reagent Trolox. Taken together, thrombin triggered apoptosis through calcium-mediated activation of cytosolic phospholipase A₂ in intestinal myofibroblasts.

• 한국식품위생안전성학회지
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• 제38권3호
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• pp.99-111
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• 2023

본 연구는 광주 내 대형마트와 온라인 마켓에서 영유아를 대상으로 판매하는 과자류 80건 및 음료류 40건의 식품첨가물(타르색소, 인공감미료), 곰팡이독소 및 영양성분(자당, 무기질)을 분석하였다. 유아용 표시 식품의 기준 및 규격이 불검출로 설정된 타르색소와 사카린나트륨은 모든 시료에서 검출되지 않았다. 과자류(기타가공품) 1건에서 인공감미료인 아세설팜 칼륨이 0.07 g/kg 검출되었으나 이는 식품첨가물의 기준 및 규격에서 정한 허용 기준치 이하였다. 곰팡이독소는 아플라톡신 및 오크라톡신 A는 검출되지 않았으며, 푸모니신 B1, B2 및 제랄레논이 각각 과자류에서 14건(9.78-78.94 ㎍/kg), 6건(5.58-11.73 ㎍/kg) 및 9건(2.96-8.83 ㎍/kg) 검출되었다. 푸모니신에 대한 기준·규격은 따로 설정되어 있지 않았으나 타 연구 결과와 비교했을 때 비슷한 수준이었으며, 제랄레논은 식품 일반에 대한 공통 기준·규격 이내로 확인되었다. 자당은 과자류에서 65건(0.02-40.94 g/내용량(g)), 음료류에서 24건(0.12-27.60 g/내용량(g)) 검출되었으나 식품유형간 유의적인 차이는 없었으며, 타 연구 결과와 비교했을 때 그 함량도 적은 편이었다. 다만, 검출 시료 89건 중 1건을 제외하고는 모두 1일 영양성분 기준치를 성인 기준으로 표시하고 있었기 때문에 제품 구입 시 영유아 기준으로 오인될 우려가 있다. 무기질은 대부분의 시료에서 검출되었으며 과자류 중 4건의 시료에서 내용량 당 아연 함량이 상한섭취량(1-2세: 6 mg/일, 3-5세: 9 mg/일)을 초과하는 수준이었다. 아연 강화식품이나 보충제의 과다 섭취가 인체의 유해성을 보인다는 다수의 보고가 있으므로 섭취시 유의할 필요가 있다. 나트륨은 과자류 80건 중 16건이 영유아용 표시 식품의 기준을 초과하였으나 모두 품목제조보고서상 영유아 섭취 대상 식품으로 표시하지 않아 해당 기준을 적용할 수 없었다. 따라서 영유아용 표시 식품의 기준·규격을 설정과 함께 현재 시행되는 기준·규격이 알맞게 적용될 수 있도록 표시 기준 강화 등의 제도적 개선이 필요할 것으로 보인다.

• BMB Reports
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• 제52권3호
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• pp.220-225
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• 2019

We have identified a mechanism to diminish the proliferative capacity of cells during cell expansion using human adipose-derived stromal cells (hAD-SCs) as a model of replicative senescence. hAD-SCs of high-passage numbers exhibited a reduced proliferative capacity with accelerated cellular senescence. Levels of key bioactive sphingolipids were significantly increased in these senescent hAD-SCs. Notably, the transcription of sphingosine kinase 1 (SPHK1) was down-regulated in hAD-SCs at high-passage numbers. SPHK1 knockdown as well as inhibition of its enzymatic activity impeded the proliferation of hAD-SCs, with concomitant induction of cellular senescence and accumulation of sphingolipids, as seen in high-passage cells. SPHK1 knockdown-accelerated cellular senescence was attenuated by co-treatment with sphingosine-1-phosphate and an inhibitor of ceramide synthesis, fumonisin $B_1$, but not by treatment with either one alone. Together, these results suggest that transcriptional down-regulation of SPHK1 is a critical inducer of altered sphingolipid profiles and enhances replicative senescence during multiple rounds of cell division.

• The Plant Pathology Journal
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• 제17권5호
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• pp.276-280
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• 2001

Fusarium isolates of Gibberella fujikuroi species complex were obtained from sorghum grown in five provinces of Korea in 1996 and 1997. These isolates were characterized based on their mating behavior, mycotoxin production, and vegetative compatibility. Only three mating populations (A, D, and F) were recovered from a total of 155 isolates examined. The relative frequency of the mating populations was significantly different: F was predominant (80%), while D and A were observed at low frequencies of 9% and 3%, respectively. Female fertile isolates were more common within F (44 our of 124) than D (2 out of 14), while none of the five A isolates were female fertile. The inbreeding effective population sizes ($\textrm{N}_e$)for mating type and male/hermaphrodite ratios in mating populations A and D produced significant amounts of fumonisins, while F isolates produced none or only traces of fumonisin B$_1$. In contrast. F isolates produced higher amounts of moniliformin (average of 3,820 ppm) than A and D isolates (averages of 77 and 1,819 ppm, respectively). Fifty-one isolates were tested for vegetative compatibility using nitrogen non-utilization mutants of each isolate, and 44 vegetative compatibility groups (VCGs) were identified. A single VC type (VC1) was found in all of the five A isolates examined. Six of the D isolates examined consisted of three VC types: two for VC2, two for VC3, and the rest for VC4. All of the F isolates tested were incompatible in every combination and , thus, each constituted a unique VCG.

• The Korean Journal of Physiology and Pharmacology
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• 제6권6호
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• pp.281-286
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• 2002

To understand the cytotoxic mechanism of $MPP^+,$ we examined the involvement of ceramide in $MPP^+-induced$ cytotoxicity to human neuroblastoma SH-SY5Y cells. When SH-SY5Y cells were exposed to $MPP^+,\;MPP^+$ induced dose-dependent cytotoxicity accompanied by 2-fold elevation of intracellular ceramide levels in SH-SY5Y cells. Three methods were used to test the hypothesis that the elevated intracellular ceramide is related to $MPP^+-induced$ cytotoxicity: $C_2-ceramide$ was directly applied to cells, sphingomyelinase (SMase) was exogenously added, and oleoylethanolamine (OE) was used to inhibit degradation of ceramide. Furthermore, inhibition of ceramide-activated protein phosphatase (CAPP), the effector of ceramide, using okadaic acid (OA) attenuated cell death but treatment of fumonisin $B_1,$ the ceramide synthase inhibitor, did not alter the cytotoxic effect of $MPP^+.$ Based on these, we suggest that the elevation of intracellular ceramide is one of the important mediators in $MPP^+-induced$ cell death.

• 한국초지조사료학회지
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• 제40권2호
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• pp.80-86
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• 2020

본 연구는 볏짚 사일리지의 곰팡이 독소 저감을 위한 효율적 방안으로 화학적 처리 방법에 따른 효능에 관한 진보적 연구 자료를 제공하고자 실시하였다. 화학적 처리 방법으로 암모니아 및 가성소다를 이용 곰팡이독소에 오염된 볏짚의 4% 수준으로 각각 처리하고 사일리지 저장에 따른 곰팡이독소 저감, 발효 품질 및 섬유소 소화에 미치는 영향을 평가 하였다. 모든 실험구에서 Aflatoxin B₁, B₂, G₁, G₂ 그리고 Fomonisin B₁, B₂ 뿐만 아니라 Dexynivalenol은 검출되지 않았으며, Ochratoxin A와 Zearalenone이 검출되었다. 그리고 Ochratoxin A은 대조구(41.23g/kg)보다 화학적 처리구에서 낮게 검출되었다(p<0.05). Zearalenone은 대조구(600.33㎍/kg) 및 암모니아 처리구(376.00㎍/kg)에 비하여 가성소다 처리구(297.44㎍/kg)가 더 낮은 결과를 나타내었다(p<0.05). 볏짚 사일리지의 pH는 암모니아 처리구(4.63)가 가장 낮았고, 가성소다 처리구가 가장(8.19) 높았다(p<0.05). lactic acid 함량은 대조구와 암모니아 처리구(10.85와 10.98mM)는 유사한 수준이었으나 가성소다 처리구(8.80mM)가 가장 낮았다(p,0.05). Propionic acid는 대조구(0.55mM)가 화학처리구에 비하여 높았으며(p<0.05), 암모니아와 가성소다 처리구간(0.09와 0.07mM)에는 유사한 함량을 나타내었다. 화학처리에 따른 볏짚 사일리지의 반추위 미생물의 NDF 및 ADF의 분해율 모두 가성소다 처리구가 가장 높은 분해율을 보였고 다음으로 암모니아 처리구이었으며, 대조구가 가장 낮은 수준을 나타내었다(p<0.05). 따라서 본 연구결과는 볏짚 사일리지 제조공정에서 암모니아 및 가성 소다 처리가 곰팡이 독소 저감 및 볏짚 사일리지의 반추위 미생물 분해율 증진에 좋은 영향을 주는 것으로 사료되며, 가성소다 처리는 암모니아 처리에 비하여 곰팡이 독소 저감 및 섬유소 분해율 증진에 더 효율적이었으나 사일리지 발효에는 비효율적 영향을 준 것으로 사료된다.

• Molecules and Cells
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• 제46권11호
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• pp.688-699
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• 2023

We set up this study to understand the underlying mechanisms of reduced ceramides on immune cells in acute rejection (AR). The concentrations of ceramides and sphingomyelins were measured in the sera from hepatic transplant patients, skin graft mice and hepatocyte transplant mice by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Serum concentrations of C24 ceramide, C24:1 ceramide, C16:0 sphingomyelin, and C18:1 sphingomyelin were lower in liver transplantation (LT) recipients with than without AR. Comparisons with the results of LT patients with infection and cardiac transplant patients with cardiac allograft vasculopathy in humans and in mouse skin graft and hepatocyte transplant models suggested that the reduced C24 and C24:1 ceramides were specifically involved in AR. A ceramide synthase inhibitor, fumonisin B₁ exacerbated allogeneic immune responses in vitro and in vivo, and reduced tolerogenic dendritic cells (tDCs), while increased P3-like plasmacytoid DCs (pDCs) in the draining lymph nodes from allogeneic skin graft mice. The results of mixed lymphocyte reactions with ceranib-2, an inhibitor of ceramidase, and C24 ceramide also support that increasing ceramide concentrations could benefit transplant recipients with AR. The results suggest increasing ceramides as novel therapeutic target for AR, where reduced ceramides were associated with the changes in DC subsets, in particular tDCs.