• International Journal of Oral Biology
• /
• 제34권1호
• /
• pp.43-48
• /
• 2009

Thrombin-induced platelet microbicidal protein (tPMP) is a small cationic peptide that exerts potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus and Streptococcus rattus BHT. Earlier evidence has suggested that tPMP targets and disrupts the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacteria or whether subsequent, presumably intracellular, events are also involved in this process. In this study, we investigated the microbicidal activity of rabbit tPMP toward S. rattus BHT cells in the presence or absence of a pretreatment with antibiotics that differ in their mechanisms of action. The streptocidal effects of tPMP on control cells (no antibiotic pretreatment) were rapid and concentration-dependent. Pretreatment of S. rattus BHT cells with either penicillin or amoxicillin (inhibitors of bacterial cell wall synthesis) significantly enhanced the anti-S. rattus BHT effects of tPMP compared with the effects against the respective control cells over most tPMP concentration ranges tested. On the other hand, pretreatment of S. rattus BHT cells with tetracycline or doxycycline (30S ribosomal subunit inhibitors) significantly decreased the streptocidal effects of tPMP over a wide peptide concentration range. Furthermore, pretreatment with rifampin (an inhibitor of DNA-dependent RNA polymerase) essentially blocked the killing of S. rattus BHT by tPMP at most concentrations compared with the respective control cells. These results suggest that tPMP exerts anti-S. rattus BHT activity through mechanisms involving both the cell membrane and intracellular targets.

• BMB Reports
• /
• 제39권5호
• /
• pp.516-521
• /
• 2006

Modifications in dietary fatty acid intake might lead to a modification in membrane phospholipid fatty acid composition. The purpose of this study was to investigate relationship between different type of oil consumption and leukocyte membrane phospholipid composition. This study was carried out in subjects utilizing butter (n = 15), margarine (n = 15), fluid oil (n = 15) and mixed types of oils (n = 15) in total 60 subjects. Leukocytes were separated from total blood by dextran sedimentation method. Membrane lipids and proteins were isolated following the cell disruption. Fatty acids of membrane phospholipids were isolated by hydrolysation with phospholipase B under ultrasonic dismembranator. Free fatty acids were identified with gas chromatography at chloroform phase. The results obtained were compared with data obtained by chromatograms of the standards. Results more prominent values of arachidic, dihomo-$\gamma$-linolenic and palmitoleic acids were found in butter-or mixed oil-user groups; eicosadienoic, eicosamonoenoic, dihomo-$\gamma$-linolenic and behenic acids in fluid oil; heptanoic, valeric, eicosadienoic and linolenic acids in margarine groups. The fatty acid composition of mixed oil was similar to butter, while other two oils were so different. From this study, it was concluded that the type of oil consumption might have an influence on phospholipid components of plasma membranes.

• IMMUNE NETWORK
• /
• 제9권6호
• /
• pp.274-284
• /
• 2009

Background: Swiprosin-1 was identified in human CD8+ lymphocytes, mature B cells and non-lymphonoid tissue. We have recently reported that swiprosin-1 is expressed in mast cells and up-regulated in both in vitro and in vivo. Methods: The expression of cytokines and swiprosin-1 were determined by by real time PCR and conventional PCR. Pharmacological inhibitors were treated to investigate potential mechanism of swiprosin-1 in mast cell activation. Actin content was evaluated by confocal microscopy and flow cytometry. Results: The swiprosin-1 augmented PMA/A23187-induced expression of cytokines and release of histamine. However, knock-down of swiprosin-1 showed only a modest effect on PMA/A23187-induced cytokine expression, suggesting that swiprosin-1 has gain-of-function characteristics. Swiprosin-1 was found in microvilli-like membrane protrusions and highly co-localized with F-actin. Importantly, either disruption of actin by cytochalasin B or inhibition of PI3 kinase, an enzyme involved in actin remodeling, by wortmannin blocked cytokine expression only in swiprosin-1-overexpressing cells. Conclusion: These results suggest that swiprosin-1 modulates mast cell activation potentially through actin regulation.

• BMB Reports
• /
• 제55권9호
• /
• pp.413-416
• /
• 2022

Ferroptosis is a type of programmed cell death distinct from apoptosis or necroptosis. Ferroptosis is well characterized by an iron-dependent accumulation of lipid peroxides and disruption of cellular membrane integrity. Many metabolic alterations can prevent or accelerate ferroptosis induction. Recent advances in analytical techniques of mass spectrometry have allowed high-throughput analysis of metabolites known to be critical for understanding ferroptosis regulatory metabolism. In this review, we introduce mass spectrometry-based analytical methods contributing to recent discovery of various metabolic pathways regulating ferroptosis, focusing on cysteine metabolism, antioxidant metabolism, and poly-unsaturated fatty acid metabolism.

• Natural Product Sciences
• /
• 제10권5호
• /
• pp.240-243
• /
• 2004

In the present study, the alcoholic extract of Terminalia arjuna (TA) and Arjunolic acid (AA) were studied fur its anti-asthmatic and anaphylactic activity. Treatment with TA (250 & 500 mg/kg) and AA (50 & 100 mg/kg) has shown significant protection against mast cell disruption in rats induced by compound 48/80. TA and AA also protected the guinea pig against histamine as well as acetylcholine induced bronchospasm. Both TA & AA exhibited better protection against histamine release than against acetylcholine release. Anti-asthmatic and anaphylactic activity may be possibly due to membrane stabilizing potential and inhibition of antigen induced histamine and acetylcholine release.

• The Plant Pathology Journal
• /
• 제31권4호
• /
• pp.323-333
• /
• 2015

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

• BMB Reports
• /
• 제54권6호
• /
• pp.305-310
• /
• 2021

Cereblon (CRBN) is a multi-functional protein that acts as a substrate receptor of the E3 ligase complex and a molecular chaperone. While CRBN is proposed to function in mitochondria, its specific roles are yet to be established. Here, we showed that knockdown of CRBN triggers oxidative stress and calcium overload in mitochondria, leading to disruption of mitochondrial membrane potential. Notably, long-term CRBN depletion using PROteolysis TArgeting Chimera (PROTAC) induced irreversible mitochondrial dysfunction, resulting in cell death. Our collective findings indicate that CRBN is required for mitochondrial homeostasis in cells.

• 대한한의학회지
• /
• 제26권1호
• /
• pp.161-173
• /
• 2005

Objective : The water extract of Seokchangpowonji-san (SWS) has traditionally been used for treatment of dementia in oriental medicine. However, little is known about the mechanism by which the water extract of SWS rescues cells from neurodegenerative disease such as Alzheimer's disease. Methods & Results: This study was designed to investigate the protective mechanisms of SWS on $\beta-amyloid$ or $H_2O_2$-induced$ cytotoxicity in neuro 2A cells. $H_2O_2$ markedly decreased the viability of neuro 2A cells, which was characterized by apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the water extract of SWS significantly reduced $H_2O_2-induced$ cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, the. extract prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and the modulation in expression of Bcl-2 family proteins in $H_2O_2­treated$ neuro 2A cells. Furthermore, pretreatment with SWS inhibited the activation of caspase-3, and in turn, degradation of ICAD/DFF45 was completely abolished in $H_2O_2-treated$ cells. Conclusion: Taken together, the data suggest that the protective effects of the water extract of SWS against $\beta-amyloid$ induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

• 상하수도학회지
• /
• 제21권6호
• /
• pp.737-744
• /
• 2007

Recently, one of the most interesting topic in the field of wastewater treatment is the disposal of excess sludge. The new concept of excess sludge reduction with recirculation of solubilized sludge via effective microorganisms for cell disruption within the wastewater treatment process has been developed in this study. The alkalophiles for degradation of sludge cell wall were isolated as Exiguobacterium sp., which could be more effectively solubilized sludge in the anaerobic condition. The SCOD of solubilized excess sludge by Exiguobacterium sp. was up to about 2,000mg/L and average TN and TP concentration of solubilized component were 117mg/L and 58mg/L, respectively and C/N ratio was more than 17. To investigate the effects of solubilized sludge by alkalophiles on excess sludge reduction and nutrient removal efficiency, the pilot plant of $DF^{(S)}-MBR$ process, combined with membrane bioreactor and sludge solubilization tank, was operated. In the control run(without sludge solubilization), the daily sludge production was about 4.54 kgMLVSS/day. However, in the $DF^{(S)}-MBR$(with sludge solubilization), the daily sludge production was decreased to 1.39kgMLVSS/day. The effluent quality satisfied the effluent regulation in both cases. Furthermore, the $DF^{(S)}-MBR$ showed relatively better TN removal efficiency in spite of high influent loading. So we concluded that the solubilized excess sludge by alkalophiles was effectively degraded in the MBR process as the carbon source and 70% of sludge reduction efficiency can be achieved.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권7호
• /
• pp.2993-2999
• /
• 2014

Saccharina japonica is a family member of Phaeophyceae (brown macro-alga) and extensively cultivated in China, Japan and Korea. Here, the potential anti-cancer effect of n-hexane fraction of S. japonica was evaluated in SK-Hep1 human hepatocellular carcinoma cells. The N-hexane fraction reduced cell viability and increased the numbers of apoptotic cells in a both dose- and time-dependent manner. Apoptosis was activated by both caspase-dependent and independent pathways. The caspase-dependent cell death pathway is mediated by cell surface death receptors and activated caspase-8 amplified the apoptotic signal either through direct activation of downstream caspase-3 or pro-apoptotic proteins (Bad, Bax and Bak) subsequently leading to the release of cytochrome c. On the other hand, caspase-independent apoptosis appeared mediated by disruption of mitochondrial membrane potential and translocation of AIF to the nucleus where they induced chromatin condensation and/or large-scale DNA fragmentation. In addition, the n-hexane fraction induced endoplasmic reticulum (ER)-stress and cell cycle arrest. The results suggested that potential anti-cancer effects of n-hexane extract from S. japonica on SK-Hep1 cells.