• 한국동물생명공학회지
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• 제37권3호
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• pp.169-175
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• 2022

Bovine mammary epithelial (MAC-T) cells are commonly used to study mammary gland development and mastitis. Lipopolysaccharide is a major bacterial cell membrane component that can induce inflammation. Autophagy is an important regulatory mechanism participating in the elimination of invading pathogens. In this study, we evaluated the mechanism underlying bacterial mastitis and mammary cell death following lipopolysaccharide treatment. After 24 h of 50 ㎍/mL lipopolysaccharide treatment, a significant decrease in the proliferation rate of MAC-T cells was observed. However, no changes were observed upon treatment of MAC-T cells with 10 ㎍/mL of lipopolysaccharide for up to 48 h. Thus, upon lipopolysaccharide treatment, MAC-T cells exhibit dose-dependent effects of growth inhibition at 10 ㎍/mL and death at 50 ㎍/mL. Treatment of MAC-T cells with 50 ㎍/mL lipopolysaccharide also induced the expression of autophagy-related genes ATG3, ATG5, ATG10, ATG12, MAP1LC3B, GABARAP-L2, and BECN1. The autophagy-related LC3A/B protein was also expressed in a dose-dependent manner upon lipopolysaccharide treatment. Based on these results, we suggest that a high dose of bacterial infection induces mammary epithelial cell death related to autophagy signals.

• 한국식품위생안전성학회지
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• 제11권4호
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• pp.227-234
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• 1996

This study was designed to characterize endotoxin-induced prostaglandin production in primary cultured rat vascular smooth muscle cells (VSMC). The time course for prostaglandin synthesis in lipopolysaccharide (LPS)-stimulated VSMC showed that the maximum production was reached in 12 hours. LPS induced prostaglandin H2 synthase (PGHS) activity in VSMC and the time course profile in the changes of PGHS activity paralleled that of total prostaglandin production. Differential treatment showed that 4 hours' exposure to LPS was enough for the maximum effect on the prostaglandin production and this effect was completely inhibited by the co-treatment of actinomycin D, a transcription inhibitor. These results suggest that LPS effect might be determined within 4 hours. Actinomycin D increased PGHS activity without affecting prostaglandin production if added 4 hours after LPS treatment. On the other hand, cyclogeximide, a translation inhibitor, augmented LPS-induced prostaglandin production if treated during first four hours, but it inhibited LPS-induced PGHS activity regardless of treatment schedule. These results suggest the existence of multiple regulating mechanisms in the LPS-induced prostaglandin synthesis.

• 한국식품위생안전성학회지
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• 제8권4호
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• pp.181-188
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• 1993

It is well known that bacterial lipopolysaccharide (LPS) stimulates the prostaglandin (PG) synthesis in various experimental system, but the mechanism and the detailed nature of its action are yet to be understood. Thus, this study was designed to characterize LPS induced PG synthesis in rat alveolar macrophage. Although results were not so much prominent, LPS stimulated PGE2 synthesis in macrophage with short term exposure, and this was thought to be mainly due to the activation of phopholipase A2+ But there was a burst in the PG synthesis 6 hours after the LPS treatment and this was accompanied with the increase of cyclooxygenase activity. This effect was not mediated by tumor necrosis factor (TNF) or platelet activating factor (PAF), and the existence of serum was prerequisite for its action. Growth factors such as epidermal growth factor (EGF) and platelet derived growth factor (PDGF) themselves did not stimulate PG synthesis and the showed stimulatory activities to some extent. Normal rat serum was more effective for the elicitation of the LPS action than growth factors. Thus, considering the amounts of growth fafctors contained in normal serum, it was suggested that another factors like LPS binding protein (LBP) might be involved in the serum effect on LPS action. Conclusively. it was thought that LPS could stimulate PG synthesis through interaction with serum factors such as EGF, PDGF and/or LBP.

• Tuberculosis and Respiratory Diseases
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• 제70권6호
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• pp.490-497
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• 2011

Background: It is difficult but important to differentiate between bacterial and viral infections, especially for respiratory infections. Hence, there is an ongoing need for sensitive and specific markers of bacterial infections. We investigated novel biomarkers for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infections. Methods: This was a prospective, observational study of patients with community acquired bacterial pneumonia, 2009 H1N1 Influenza A infection, and healthy controls. Serum samples were obtained on the initial visit to the hospital and stored at $-80^{\circ}C$. We evaluated CRP (C-reactive protein), PCT (procalcitonin), LBP (lipopolysaccharide-binding protein) and copeptin. These analytes were all evaluated retrospectively except CRP. Receiver operating characteristic curve (ROC) analyses were performed on the resulting data. Results: Enrolled patients included 27 with community acquired bacterial pneumonia, 20 with 2009 H1N1 Influenza A infection, and 26 who were healthy controls. In an ROC analysis for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection, areas under the curve (AUCs) were 0.799 for CRP (95% Confidence interval [CI], 0.664~0.934), 0.753 for PCT (95% CI, 0.613~0.892) and 0.684 for LBP (95% CI, 0.531~0.837). Copeptin was not different among the three groups. Conclusion: These findings suggest that serum CRP, PCT and LBP can assist physicians in discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection.

• 대한수의학회지
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• 제59권2호
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• pp.75-80
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• 2019

Enrofloxacin, a fluoroquinolone, is a broad-spectrum antibiotic widely used in veterinary medicine that inhibits the action of bacterial DNA gyrase, resulting in anti-bacterial effects. This study was performed to examine whether enrofloxacin has modulatory and anti-inflammatory activity on immune cells. A few studies have reported the anti-inflammatory effects of enrofloxacin. In this study, we used mouse spleen cells treated with lipopolysaccharide (LPS) and examined the effects of enrofloxacin. Several assays were performed in LPS-treated spleen cells after the enrofloxacin treatment. Enrofloxacin inhibited the metabolic activity and mitochondrial membrane potential of LPS-treated spleen cells significantly. On the other hand, enrofloxacin did not alter the proportion of the subsets in spleen cells, and did not induce cell death. The production of tumor necrosis factor-alpha in LPS-treated spleen cells was inhibited by enrofloxacin. Overall, enrofloxacin had modulatory activity in spleen cells treated with LPS. These data may broaden the use of enrofloxacin as an antibiotic with anti-inflammatory activity in veterinary clinics.

• Fisheries and Aquatic Sciences
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• 제6권3호
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• pp.130-134
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• 2003

Proinflammatory effects of bacterial lipopolysaccharide (LPS) have been assessed by analysing the induction of two inflammatory genes, $interleukin-1\beta$ $(IL-1\beta)$ and cyclooxygenase-2 (COX-2), in rainbow trout (Oncorhynchus mykiss) macrophage cells. Production of a metabolite of arachidonic acid by COX-2, prostaglandin $E_2\;(PGE_2)$, was also analysed in macrophage cells after LPS stimulation. Northern blot analysis revealed that LPS $(5{\mu}g/mL)$ significantly upregulated $IL-1\beta$ (54 times) and COX-2 (40.7 times) gene expression in macrophage cells after 4 h stimulation. According to RT-PCR (Reverse Transcription Polymerase Chain Reaction) analysis, $IL-1\beta$ gene induction in LPS stimulated macrophage cells was started within 1h and significantly increased thereafter until 4h. Meanwhile, COX-2 gene induction by LPS was delayed in comparison with $IL-1\beta$ gene induction as a faint band was observed after 4h stimulation in head kidney macrophage cells. LPS also significantly increased $PGE_2$ production in head kidney leucocytes, presumably via activating COX-2 expression that metabolites arachidonic acid to $PGE_2$. In conclusion, it was demonstrated that LPS could induce two main inflammatory and immune related genes, $IL-1\beta$ and COX-2, and increase $PGE_2$ production in trout head kidney macrophage cells, representing a strong inflammatory activity.

• Advances in Traditional Medicine
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• 제6권2호
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• pp.134-143
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• 2006

The capacities of bacterial DNA, extracted from Salmonella typhimurium, and lipopolysaccharide (LPS), extracted from Salmonella minnesota, to activate mouse peritoneal macrophages in vitro were compared. Activation was assessed by estimating e levels of 3 cytokines, IL-10, IL-12, and $IL-1{\beta}$, at time intervals of 3, 6, 9, and 24 h after addition of LPS and/or DNA to macrophage cultures. Cytokine levels in culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA) and cytokine mRNA levels were estimated based on band intensity in cultured cells by reverse transcriptase-polymerase chain reaction (RT-PCR). Results obtained demonstrated the ability of DNA and LPS to elicit increased production of all 3 cytokines as compared to controls. In the amount tested, LPS appeared to be a more potent inducer of IL-12, and $IL-1{\beta}$, whereas DNA induced higher levels of IL-10. DNA and LPS, used in combination, exhibited neither an additive nor a synergistic effect. Rather, an antagonist effect appeared to occur. RT-PCR results correlated well with ELISA.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.331-343
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• 1998

Sublethal dose of bacterial lipopolysaccharide (LPS) would induce protection against cardiac ischemic/reperfusion (I/R) injury. This study examines the following areas: 1) the temporal induction of the cardio-protection produced by LPS; and 2) the relations between a degree of protection and the myocardial prostacyclin ($PGI_2$) production. Rats were administered LPS (2 mg/kg, i.v.), and hearts were removed 1, 4, 8, 14, 24, 48, 72,and 96 h later. Using Langendorff apparatus, haemodynamic differences during 25 min of global ischemia/30 min reperfusion were investigated. The concentration of $PGI_2$ in aliquots of the coronary effluent was determined by radioimmunoassay as its stable hydrolysis product $6-keto-PGF1_{\alpha}$ and lactate dehydrogenase release were measured as an indicative of cellular injury. LPS-induced cardiac protection against I/R injury appeared 4 h after LPS treatment and remained until 96 h after treatment. $PGI_2$ release increased 2-3 fold at the beginning of reperfusion compared to basal level except in hearts treated with LPS for 48 and 72 h. In hearts removed 48 and 72 h after LPS treatment, basal $PGI_2$ was increased. To determine the enzymatic step in relation to LPS-induced basal $PGI_2$ production, we examined prostaglandin H synthase (PGHS) protein expression, a rate limiting enzyme of prostaglandin production, by using Western blot analysis. LPS increased PGHS protein expression in hearts at 24, 48, 72, 96 h after LPS treatment. Induction of PGHS expression appeared in both isotypes of PGHS, a constitutive PGHS-1 and an inducible PGHS-2. To identify the correlationship between $PGI_2$ production and the cardioprotective effect against I/R injury, indomethacin was administered in vivo or in vitro. Indomethacin did not inhibit LPS-induced cardioprotection, which was not affected by the duration of LPS treatment. Taken together, our results suggest that $PGI_2$ might not be the major endogenous mediator of LPS-induced cardioprotection.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.291-297
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• 2015

An oral environment is constantly exposed to environmental factors and microorganisms. The periodontal ligament (PDL) fibroblasts within this environment are subject to bacterial infection and allergic reaction. However, how these condition affect PDL fibroblasts has yet to be elucidated. PDL fibroblasts were isolated from healthy donors. We examined using reverse transcription-polymerase chain reaction and measuring the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$). This study investigated the receptors activated by exogenous bacterial pathogens (Lipopolysaccharide and peptidoglycan) and allergens (German cockroach extract and house dust mite) as well as these pathogenic mediators-induced effects on the intracellular $Ca^{2+}$ signaling in human PDL fibroblasts. Moreover, we evaluated the expression of pro-inflammatory cytokines (interleukin (IL)-$1{\beta}$, IL-6, and IL-8) and bone remodeling mediators (receptor activator of NF-${\kappa}B$ ligand and osteoprotegerin) and intracellular $Ca^{2+}$-involved effect. Bacterial pathogens and allergic mediators induced increased expression of pro-inflammatory cytokines, and these results are dependent on intracellular $Ca^{2+}$. However, bacterial pathogens and allergic mediators did not lead to increased expression of bone remodeling mediators, except lipopolysaccharide-induced effect on receptor activator of NF-${\kappa}B$ ligand expression. These experiments provide evidence that a pathogens and allergens-induced increase in $[Ca^{2+}]_i$ affects the inflammatory response in human PDL fibroblasts.

• 한국약용작물학회지
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• 제15권6호
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• pp.451-456
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• 2007

Curcumin, a polyphenolic antioxidant purified from turmeric, has been known to possess various biological activities such as anti-oxidative, anti-inflammatory and anti-cancer effects. In this study, we have explored anti-inflammatory effect of curcumin using Gram (-) bacterium-derived endotoxin (lipopolysaccharide: LPS) and macrophage cell line RAW264.7. Curcumin suppressed NO production in LPS-activated RAW264.7 cells in a dose-dependent manner, Curcumin also blocked the activation of $NF-{\kappa}B$ but not AP-1 according to luciferase assay. Furthermore, this compound suppressed the phosphorylation of a series of intracellular signaling components such as Src, JAK-2, Akt, IKK and $I{\kappa}B{\alpha}$ under LPS stimulation in a time dependent manner, Therefore, our data suggest that curcumin was able to protect the host from Gram(-) bacterial-infection-mediated inflammatory symptoms.