scholarly journals The effect of endotoxin on functional parameters of mammary CID-9 cells

Reproduction ◽  
2004 ◽  
Vol 127 (3) ◽  
pp. 397-406 ◽  
Author(s):  
B Safieh-Garabedian ◽  
G M Mouneimne ◽  
W El-Jouni ◽  
M Khattar ◽  
R Talhouk

The effect of endotoxin on mammary CID-9 cells, which differentiate in culture and express β-casein, was investigated. Cells in culture supplemented with lactogenic hormones and dripped with EMS-Matrix (EMS-drip), were treated daily with endotoxin (0.5–500 μg/ml). Endotoxin at concentrations of less or equal to 10 μg/ml did not affect cell growth and viability up to 5 days post endotoxin treatment. Endotoxin (0.01–10 μg/ml) was added to the culture medium, upon confluence, and functional parameters were examined within 48 h post endotoxin treatment. Nuclear factor-κB (NF-κB) (p52) increased in nuclear extracts from endotoxin-stimulated cells within 1 h of treatment, while β-casein mRNA and protein expression decreased in a concentration-dependent manner at 24 and 48 h post treatment. Zymography showed that the 72 and 92 kDa gelatinase activity increased in cells at 24 and 48 h post endotoxin treatment at 10 and 50 μg/ml. At the latter concentration, the active form of 72 kDa gelatinase was induced at 48 h. Interleukin-6 and tumor necrosis factor-α levels increased at 1–3 h post endotoxin treatment and peaked at 6 h in cells on plastic and EHS-drip. Nerve growth factor (NGF) levels increased in control and endotoxin-treated cells in a time-dependent manner, and endotoxin increased NGF levels in culture at 6 and 9 h post endotoxin treatment. This study shows that endotoxin activated NF-κB, suppressed β-casein expression and upregulated gelatinases, cytokines and NGF. This model could be used to investigate the role of mammary cells in initiating and propagating inflammation and to test candidate molecules for potential anti-inflammatory properties.

Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 5125-5134 ◽  
Author(s):  
Dan Gratschev ◽  
Christoffer Löf ◽  
Jari Heikkilä ◽  
Anders Björkbom ◽  
Pramod Sukumaran ◽  
...  

Calcium entry is one of the main regulators of intracellular signaling. Here, we have described the importance of sphingosine, sphingosine kinase 1 (SK1), and sphingosine 1-phosphate (S1P) in regulating calcium entry in thyroid FRTL-5 cells. In cells incubated with the phosphatase inhibitor calyculin A, which evokes calcium entry without mobilizing sequestered intracellular calcium, sphingosine inhibited calcium entry in a concentration-dependent manner. Furthermore, inhibiting SK1 or the ATP-binding cassette ABCC1 multidrug transporter attenuated calcium entry. The addition of exogenous S1P restored calcium entry. Neither sphingosine nor inhibition of SK1 attenuated thapsigargin-evoked calcium entry. Blocking S1P receptor 2 or phospholipase C attenuated calcium entry, whereas blocking S1P receptor 3 did not. Overexpression of wild-type SK1, but not SK2, enhanced calyculin-evoked calcium entry compared with mock-transfected cells, whereas calcium entry was decreased in cells transfected with the dominant-negative G82D SK1 mutant. Exogenous S1P restored calcium entry in G82D cells. Our results suggest that the calcium entry pathway is blocked by sphingosine and that activation of SK1 and the production of S1P, through an autocrine mechanism, facilitate calcium entry through activation of S1P receptor 2. This is a novel mechanism by which the sphingosine-S1P rheostat regulates cellular calcium homeostasis.


2014 ◽  
Vol 306 (12) ◽  
pp. C1119-C1128 ◽  
Author(s):  
Xiao-Juan Feng ◽  
Shu-Xia Liu ◽  
Chao Wu ◽  
Peng-Peng Kang ◽  
Qing-Juan Liu ◽  
...  

Our previous experiment confirmed that high-mobility group box chromosomal protein 1 (HMGB1) was involved in the pathogenesis of Lupus nephritis (LN) by upregulating the proliferation of the mouse mesangial cell line (MMC) through the cyclin D1/CDK4/p16 system, but the precise mechanism is still unknown. Therefore, in the present study, we demonstrated that HMGB1 induced the proliferation of MMC cells in a time- and concentration-dependent manner, downregulated phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression, increased the level of Akt serine 473 phosphorylation, and induced p65 subunit nuclear translocation. The overexpression of PTEN prevented the upregulation of HMGB1-induced proliferation by blocking the activation of Akt. The knockdown of Akt by siRNA technology and blocking the nuclear factor-κB (NF-κB) pathway using pyrrolidine dithiocarbamate (PDTC) and SN50, inhibitors of NF-κB, both attenuated the HMGB1-induced proliferation by counteracting the activation of the cyclin D1. In addition, while sh-Akt partly blocked the nuclear translocation of the p65 subunit, PDTC did not affect the activation of the Akt induced by HMGB1 in MMC cells. These findings indicate that HMGB1 induced the proliferation of MMC cells by activating the PTEN/phosphoinositide-3-kinase (PI3K)/Akt/NF-κB signaling pathway.


Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 664-672 ◽  
Author(s):  
Markus Warmuth ◽  
Nicola Simon ◽  
Olga Mitina ◽  
Ruth Mathes ◽  
Doriano Fabbro ◽  
...  

The leukemogenic tyrosine kinase Bcr-Abl contains a highly conserved inhibitor-binding pocket (IBP), which serves as a binding site for imatinib mesylate. Mutations at the IBP may lead to resistance of the Abl kinase against imatinib mesylate. To examine the mechanisms of imatinib mesylate binding and resistance in more detail, we created several point mutations at amino acid positions 315 and 380 of Abl, blocking the access to the IBP and rendering Bcr-Abl imatinib mesylate–resistant. Moreover, introduction of a mutation destabilizing the inactive conformation of Abl (Asp276Ser/Glu279Ser) also led to imatinib mesylate resistance, suggesting that the inhibitor required inactivation of the kinase prior to binding. These Bcr-Abl mutants were then used to evaluate the binding mode and specificity of 2 compounds, PP1 and CGP76030, originally characterized as Src kinase inhibitors. Both compounds inhibited Bcr-Abl in a concentration-dependent manner by overlapping binding modes. However, in contrast to imatinib mesylate, PP1 and CGP76030 blocked cell growth and survival in cells expressing various inhibitor-resistant Abl mutants. Studies on the potential signaling mechanisms demonstrated that in cells expressing inhibitor-resistant Bcr-Abl mutants, PP1 and CGP76030 inhibited the activity of Src family tyrosine kinases and Akt but not signal transducer and activator of transcription–5 (STAT5) and JUN kinase (Jnk). The results suggest that the use of Src kinase inhibitors is a potential strategy to prevent or overcome clonal evolution of imatinib mesylate resistance in Bcr-Abl+ leukemia.


Endocrinology ◽  
2015 ◽  
Vol 156 (12) ◽  
pp. 4741-4754 ◽  
Author(s):  
Juan Pablo Nicola ◽  
Victoria Peyret ◽  
Magalí Nazar ◽  
Jorge Miguel Romero ◽  
Ariel Maximiliano Lucero ◽  
...  

Nitric oxide (NO) is a ubiquitous signaling molecule involved in a wide variety of cellular physiological processes. In thyroid cells, NO-synthase III-endogenously produced NO reduces TSH-stimulated thyroid-specific gene expression, suggesting a potential autocrine role of NO in modulating thyroid function. Further studies indicate that NO induces thyroid dedifferentiation, because NO donors repress TSH-stimulated iodide (I−) uptake. Here, we investigated the molecular mechanism underlying the NO-inhibited Na+/I− symporter (NIS)-mediated I− uptake in thyroid cells. We showed that NO donors reduce I− uptake in a concentration-dependent manner, which correlates with decreased NIS protein expression. NO-reduced I− uptake results from transcriptional repression of NIS gene rather than posttranslational modifications reducing functional NIS expression at the plasma membrane. We observed that NO donors repress TSH-induced NIS gene expression by reducing the transcriptional activity of the nuclear factor-κB subunit p65. NO-promoted p65 S-nitrosylation reduces p65-mediated transactivation of the NIS promoter in response to TSH stimulation. Overall, our data are consistent with the notion that NO plays a role as an inhibitory signal to counterbalance TSH-stimulated nuclear factor-κB activation, thus modulating thyroid hormone biosynthesis.


2007 ◽  
Vol 282 (38) ◽  
pp. 27622-27632 ◽  
Author(s):  
Byeong-Churl Jang ◽  
Su-Haeng Sung ◽  
Jong-Gu Park ◽  
Jong-Wook Park ◽  
Jae Hoon Bae ◽  
...  

COX-2 and its products, including prostaglandin E2, are involved in many inflammatory processes. Glucosamine (GS) is an amino monosaccharide and has been widely used for alternative regimen of (osteo) arthritis. However, the mechanism of action of GS on COX-2 expression remains unclear. Here we describe a new action mechanism of glucosamine hydrochloride (GS-HCl) to tackle endogenous and agonistdriven COX-2 at protein level. GS-HCl (but not GS sulfate, N-acetyl GS, or galactosamine HCl) resulted in a shift in the molecular mass of COX-2 from 72–74 to 66–70 kDa and concomitant inhibition of prostaglandin E2 production in a concentration-dependent manner in interleukin (IL)-1β-treated A549 human lung epithelial cells. Remarkably, GS-HCl-mediated decrease in COX-2 molecular mass was associated with inhibition of COX-2 N-glycosylation during translation, as assessed by the effect of tunicamycin, the protein N-glycosylation inhibitor, or of cycloheximide, the translation inhibitor, on COX-2 modification. Specifically, the effect of low concentration of GS-HCl (1 mm) or of tunicamycin (0.1 μg/ml) to produce the aglycosylated COX-2 was rescued by the proteasomal inhibitor MG132 but not by the lysosomal or caspase inhibitors. However, the proteasomal inhibitors did not show an effect at 5 mm GS-HCl, which produced the aglycosylated or completely deglycosylated form of COX-2. Notably, GS-HCl (5 mm) also facilitated degradation of the higher molecular species of COX-2 in IL-1β-treated A549 cells that was retarded by MG132. GS-HCl (5 mm) was also able to decrease the molecular mass of endogenous and IL-1β- or tumor necrosis factor-α-driven COX-2 in different human cell lines, including Hep2 (bronchial) and H292 (laryngeal). However, GS-HCl did not affect COX-1 protein expression. These results demonstrate for the first time that GS-HCl inhibits COX-2 activity by preventing COX-2 co-translational N-glycosylation and by facilitating COX-2 protein turnover during translation in a proteasome-dependent manner.


2008 ◽  
Vol 182 (1) ◽  
pp. 171-184 ◽  
Author(s):  
James E. Vince ◽  
Diep Chau ◽  
Bernard Callus ◽  
W. Wei-Lynn Wong ◽  
Christine J. Hawkins ◽  
...  

Synthetic inhibitor of apoptosis (IAP) antagonists induce degradation of IAP proteins such as cellular IAP1 (cIAP1), activate nuclear factor κB (NF-κB) signaling, and sensitize cells to tumor necrosis factor α (TNFα). The physiological relevance of these discoveries to cIAP1 function remains undetermined. We show that upon ligand binding, the TNF superfamily receptor FN14 recruits a cIAP1–Tnf receptor-associated factor 2 (TRAF2) complex. Unlike IAP antagonists that cause rapid proteasomal degradation of cIAP1, signaling by FN14 promotes the lysosomal degradation of cIAP1–TRAF2 in a cIAP1-dependent manner. TNF-like weak inducer of apoptosis (TWEAK)/FN14 signaling nevertheless promotes the same noncanonical NF-κB signaling elicited by IAP antagonists and, in sensitive cells, the same autocrine TNFα-induced death occurs. TWEAK-induced loss of the cIAP1–TRAF2 complex sensitizes immortalized and minimally passaged tumor cells to TNFα-induced death, whereas primary cells remain resistant. Conversely, cIAP1–TRAF2 complex overexpression limits FN14 signaling and protects tumor cells from TWEAK-induced TNFα sensitization. Lysosomal degradation of cIAP1–TRAF2 by TWEAK/FN14 therefore critically alters the balance of life/death signals emanating from TNF-R1 in immortalized cells.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xubin Bao ◽  
Cai Chen ◽  
Liyong Yuan

Triptolide (T10) is a common anti-inflammatory and analgesic drug. However, the activation of microglia and elimination of the corresponding inflammatory response are new targets for the treatment of neuropathic pain. Chemokine CCL (CCL2) is a key mediator for activating microglia. In this study, the effects of triptolide on the activation and polarization of microglia cells and CCL2 and its corresponding receptor, chemokine receptor 2 (CCR2), were mainly discussed. Microglia were stimulated with 1 μg/mL lipopolysaccharide (LPS) and pretreated with 10, 20, and 40 nM T10 and CCR2 antagonist (RS102895), respectively. The quantitative polymerase chain reaction (QPCR) and western blot results showed that T10 could obviously inhibit the upregulation of CCL2 and CCR2 induced by LPS stimulation in microglia cells, inhibit the fluorescence intensity of glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) antibody immunostaining in cells, and upregulate the fluorescence intensity of arginase 1 antibody in cells. The expression of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) was inhibited in a dose-dependent manner. RS102895 can significantly reverse the activation and M2 polarization of microglia pretreated with 40 nM T10 and weaken the anti-inflammatory effect of T10. The addition of CCL2 did not extremely affect the function of RS102895. T10 may inhibit microglia activation and M1 polarization by inhibiting the expression of CCL2 and CCR2, promoting M2 polarization, reducing the level of inflammatory factors in cells, and exerting its analgesic effect, which is worthy of clinical promotion as a drug for neuropathic pain.


2002 ◽  
Vol 46 (7) ◽  
pp. 2095-2103 ◽  
Author(s):  
Stéphane Carryn ◽  
Françoise Van Bambeke ◽  
Marie-Paule Mingeot-Leclercq ◽  
Paul M. Tulkens

ABSTRACT The activities of ampicillin, meropenem, azithromycin, gentamicin, ciprofloxacin, and moxifloxacin against intracellular hemolysin-positive Listeria monocytogenes were measured in human THP-1 macrophages and were compared with the extracellular activities observed in broth. All extracellular concentrations were adjusted to explore ranges that are clinically achievable in human serum upon conventional therapy. In broth, ampicillin, meropenem, and azithromycin were only bacteriostatic, whereas gentamicin, ciprofloxacin, and moxifloxacin were strongly bactericidal in a concentration-dependent manner. In cells, ampicillin, meropenem, azithromycin, and ciprofloxacin were slightly bactericidal (0.3- to 0.8-log CFU reductions), moxifloxacin was strongly bactericidal (2.1-log CFU reduction), and gentamicin was virtually inactive. The difference in the efficacies of moxifloxacin and ciprofloxacin in cells did not result from a difference in levels of accumulation in cells (6.96 ± 1.05 versus 7.75 ± 1.03) and was only partially explainable by the difference in the MICs (0.58 ± 0.04 versus 1.40 ± 0.17 mg/liter). Further analysis showed that intracellular moxifloxacin expressed only approximately 1/7 of the activity demonstrated against extracellular bacteria and ciprofloxacin expressed only 1/15 of the activity demonstrated against extracellular bacteria. Gentamicin did not increase the intracellular activities of the other antibiotics tested. The data suggest (i) that moxifloxacin could be of potential interest for eradication of the intracellular forms of L. monocytogenes, (ii) that the cellular accumulation of an antibiotic is not the only determinant of its intracellular activity (for fluoroquinolones, it is actually a self-defeating process as far as activity is concerned), and (iii) that pharmacodynamics (activity-to-concentration relationships) need to be considered for the establishment of efficacy against intracellular bacteria, just as they are for the establishment of efficacy against extracellular infections.


Open Medicine ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 719-725 ◽  
Author(s):  
Nianshui Jing ◽  
Xinnan Li

AbstractMicroglia plays a complex role in neuroinflammation, which has been implicated in neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. This study aims to explore the effect and mechanism of Dihydromyricetin (DHM) on lipopolysaccharide (LPS)-induced inflammation in microglial BV-2 cells. Cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay. The pro-inflammatory mediators and cytokines including interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α); inducible nitric oxide synthase (iNOS); and cyclooxygenase 2 (COX-2) were measured by enzyme-linked immunosorbent assay (ELISA) and/or quantitative real-time PCR (qRT-PCR). The expression of p-p65, p-IκBα, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) were analyzed by western blot. The present study showed that DHM treatment alleviated LPS-induced viability reduction, suppressed the mRNA levels of IL-6, IL‐1β and TNF-α, inhibited the mRNA and protein expression of iNOS and COX-2, and attenuated the activation of NF-кB and TLR4 signaling in a concentration-dependent manner. In conclusion, DHM exerts an anti-inflammatory effect on LPS-induced BV-2 microglial cells, possibly through TRL4/NF-κB signaling pathway.


2020 ◽  
Vol 15 (1) ◽  
pp. 1934578X1989950
Author(s):  
Sungchan Jang ◽  
Min-Seon Kim ◽  
Taejin Park ◽  
Ji H. Sim ◽  
Seung-Young Kim

Ligularia taquetii (H. Lev. & Vaniot) Nakai has traditionally been used to treat inflammation and skin swelling in the Jeju Island, Korea. The objective of this study was to investigate the anti-inflammatory and anti-adipogenic effects of Ligularia taquetii ethanoic extract (LTE), in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and 3T3-L1 adipocytes. Lipopolysaccharide-induced inflammation was reduced by LTE in a concentration-dependent manner, via the nuclear factor-κB signaling pathway. Ligularia taquetii ethanoic extract (100 µg/mL) inhibited the LPS-induced production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS), by 60% and 100%, respectively. In comparison, 200 and 100 µg/mL LTE suppressed the LPS-stimulated production of prostaglandin-2 (PGE2) and cyclooxygenase-2 by 50% and 80%, respectively. Ligularia taquetii ethanoic extract also inhibited the secretion of interleukin-1β and interleukin-6 at 300 and 100 μg/mL by 15% and 30%, respectively. High-performance liquid chromatography-photodiode array analysis, combined with mass analysis, revealed chlorogenic acid (CGA) as the anti-inflammatory constituent of LTE. Conversely, 25, 50, 100, and 200 μg/mL LTE lowered the lipid accumulation by 6%, 8%, 25%, and 60%, respectively, while simultaneously increasing cell viability by 7%, 14%, 34%, and 78%. The anti-adipogenic effect of LTE at 100 µg/mL was equivalent to that of CGA at 50 µg/mL. However, LTE treatment promoted cell proliferation by about 30% compared to its CGA-treated counterpart. These results suggest the potential of LTE as a new resource in the discovery of anti-inflammatory and anti-obesity drugs.


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