• Molecules and Cells
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• 제38권7호
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• pp.657-662
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• 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells.

• 생약학회지
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• 제29권4호
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• pp.391-395
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• 1998

The phagocytic activity of murine peritoneal macrophages was determined by lucigenin chemiluminescence with luminometer and engulfment of fluorescein-conjugated E. coli particles. 70% MeOH extract of Lithospermi Radix was fractionated successively with hexane, methylene chloride, n-BuOH and water. The water fraction (m.w. 500 to 1,000) enhanced the lucigenin chemiluminescence and the engulfment of fluorescein-conjugated E. coli particles in murine peritoneal macrophages. The water fraction suppressed the production of nitric oxide in the macrophages. These results suggest that an active fraction of phagocytosis in Lithos-permi Radix is the water fraction and the molecular weight is 500 to 1,000.

• 약학회지
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• 제42권6호
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• pp.567-571
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• 1998

The phagocytic activity of murine peritoneal macrophage, was determined by lucigenin chemiluminescence and engulfment of fluorescein-conjugated E. coli particle. The acti vity-guided fractionation upon the methylenechloride fraction of Aurantii immaturi pericarpium led to the isolation of a flavonoid, isosinensetin, as a suppressive component of phagocytosis. Isosinensetin suppressed the lucigenin chemiluminescence and the engulfment of fluorescein-conjugated E. coli particles and enhanced the production of nitric oxide in murine peritoneal macrophage.

• Applied Microscopy
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• 제35권4호
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• pp.84-90
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• 2005

호중구는 다양한 원인에 의해서 발생되는 급성 폐 손상의 발병기전에 중요한 역할을 담당한다. 폐 손상 시 순환계로부터 유입된 호중구들에 대한 폐포강 대식세포의 탐식작용이 증가될 경우 손상기전에 미치는 영향을 알아 보기 위해 내독소를 흰쥐의 기관지 내로 분무하고 유기게르마늄을 복강으로 투여하였다. 실험 결과 내독소 투여 5시간 후 체중당 폐 무게와 폐 세척액 내 단백질 함량은 유의하게 (p<0.001) 증가되었으나, 게르마늄 병행 투여로 폐 무게와 단백질 함량은 현저하게 (p<0.001, p<0.01) 감소되었다. 내독소 투여군은 폐 손상과 함께 폐포강 내 호중구는 유의하게 (p<0.05) 증가되었으나, 게르마늄의 투여로 감소되었고 폐포강 내 탐식된 호중구의 비율은 증가되었다. 이와 같은 결과들을 볼 때, 유기 게르마늄은 내독소증에 의한 급성 폐 손상에서 폐포강 대식세포들의 호중구 탐식작용을 증가시켜 폐 손상을 감소시킬 수 있는 것으로 나타났다.

• 생약학회지
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• 제30권4호
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• pp.363-367
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• 1999

Palmultang(PMT) consists of Ginseng Radix Alba, Atractylodis Rhizoma Alba, Hoelen, Glycyrrhizae Radix, Rehmanniae Radix Preparata, Paeoniae Radix, Cnidii Rhizoma and Angelicae Gigantis Radix. PMT enhanced the lucigenin chemiluminescence and the engulfment of fluorescein-conjugated E. coli particles and inhibited the production of nitric oxide in murine peritoneal macrophage. PMT enhanced the production of ${\gamma}-interferon$, interleukin-2 and the cell viability in murine thymocyte, but did not affect the production of interleukin-4. These results indicate that PMT enhances the phagocytosis of macrophage via the stimulation of ${\gamma}-interferon$ production in $T_H1$ cells and the reduction of nitric oxide production in peritoneal macrophage.

• 약학회지
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• 제46권1호
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• pp.69-74
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• 2002

The effects of genistein on murine thymocytes for inducing apoptotic cell death and phagocytic activity of peritoneal macrophage were studied in vitro. Addition of genistein (10 and 50$\mu$M) to cultured thymocytes from BALB/c mice definitely promoted DNA fragmentation. Also, cytofluorometric analysis of these cells demonstrated a reduction in mitochondrial transmembrane potential ($\Delta$Ψm). But, repeated administration of genistein (1 mg/mouse/day) to mice for 7 days did not cause any detectable DNA fragmentation. Genistein decreased lucigenin chemiluminescence and engulfment of fluorescein-conjugated E. coli particles in peritoneal macrophage. These results suggest that genistein induce an apoptosis of thymocyte via reduction in $\Delta$Ψm and decrease phagocytic activity of peritoneal macrophage in vitro.

• 셀메드
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• 제7권1호
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• pp.3.1-3.2
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• 2017

The efficient removal of dead cells is an evolutionarily conserved process essential for homeostasis in multicellular organisms. The phagocytosis involves a series of steps that ultimately leads the detection of apoptotic cell by the phagocytes and the subsequent engulfment and degradation of corpse. The uptake of apoptotic cells by phagocytes not only removes debris from tissues but also generates an anti-inflammatory signal that blocks tissue inflammation. Conversely, impaired clearance of dead cells can cause loss of immune tolerance and the development of various inflammation-associated diseases such as autoimmunity, but can also affect cancer development. This review will discuss current understanding of the molecular mechanism of apoptotic cell phagocytosis and how they may be related to human diseases.

• 사상체질의학회지
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• 제13권3호
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• pp.102-113
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• 2001

The purpose of this research was to investigate the effects of Seungyangikkitang (SIT) on the immune cells in BALB/c mice. SIT (500mg/kg) was administerd p.o. once a day for 7 days. SIT enhanced the proliferation of thymocytes, but decreased the proliferation of splenocytes. SIT enhanced the subpopulation of cytotoxic T cells in thymocytes and helper T cells in splenocytes, but did not affect the subpopulation of B220/Thy1 cells. SIT enhanced the production of γ-interferon and interleukin-2 in thymocytes, splenocytes and serum, but did not affect the production of interleukin-4. SIT suppressed the production of nitric oxide, but enhanced the lucigenin chemiluminescence and the engulfment of FITC-conjugated E. coli particles in peritoneal macrophages. These results suggest that SIT has a potent activity on the specific immunity via the cytokine secretion of Th1 cells and the non-specific immunity via the phagocytic activity of macrophages in vivo.

• ALGAE
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• 제29권2호
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• pp.137-152
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• 2014

Mixotrophic protists play diverse roles in marine food webs as predators and prey. Thus, exploring mixotrophy in phototrophic protists has emerged as a critical step in understanding marine food webs and cycling of materials in marine ecosystem. To investigate the feeding of newly described mixotrophic dinoflagellate Ansanella granifera, we explored the feeding mechanism and the different types of species that A. granifera was able to feed on. In addition, we measured the growth and ingestion rates of A. granifera feeding on the prasinophyte Pyramimonas sp., the only algal prey, as a function of prey concentration. A. granifera was able to feed on heterotrophic bacteria and the cyanobacterium Synechococcus sp. However, among the 12 species of algal prey offered, A. granifera ingested only Pyramimonas sp. A. granifera ingested the algal prey cell by engulfment. With increasing mean prey concentration, the growth rate of A. granifera feeding on Pyramimonas sp. increased rapidly, but became saturated at a concentration of $434ngCmL^{-1}$ (10,845 cells $mL^{-1}$). The maximum specific growth rate (i.e., mixotrophic growth) of A. granifera feeding on Pyramimonas sp. was $1.426d^{-1}$, at $20^{\circ}C$ under a 14 : 10 h light-dark cycle of $20{\mu}Em^{-2}s^{-1}$, while the growth rate (i.e., phototrophic growth) under similar light conditions without added prey was $0.391d^{-1}$. With increasing mean prey concentration, the ingestion rate of A. granifera feeding on Pyramimonas sp. increased rapidly, but slightly at the concentrations ${\geq}306ngCmL^{-1}$ (7,649 cells $mL^{-1}$). The maximum ingestion rate of A. granifera feeding on Pyramimonas sp. was 0.97 ng C $predator^{-1}d^{-1}$ (24.3 cells $grazer^{-1}d^{-1}$). The calculated grazing coefficients for A. granifera feeding on co-occurring Pyramimonas sp. were up to $2.78d^{-1}$. The results of the present study suggest that A. granifera can sometimes have a considerable grazing impact on the population of Pyramimonas spp.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1106-1110
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• 2001

The parasporal biogenesis of crystal inclusion during the sporulation of Bacillus sphaericus strain 1593 was observed using transmission electron microscopy. The crystal biogenesis and sporulation process involved a sequence of events talking about 10 h. The sporulation Precesses were found to be similar to previous findings. The crystal biogenesis of B. sphaericus was initiated at the start of engulfment and nearly completed by the time of exosporium formation. The crystal formation was clearly associated with the outer forespore membrane from stages III through VI, and the crystals grew from polypeptide-like chains originated from the outer forespore membrane. These observations are different from previous findings, which report no association with the forespore membrane. The crystals were located adjacent to the outer membrane of the spore until the release stage. The axes size of the bipyramidal crystal was approximately $0.25{\mu}m{\times}42{\mu}m$. During crystal biogenesis, the crystal development could be classified into four stages; initiation stage Cl (sporulation stage . III), growth stage C2 (sporulation III to V), envelopment and maturation C3 (sporulation V to V), and finally release stage C4 (sporulation Vll).