Time course of inflammatory and remodeling events in a murine model of asthma: effect of steroid treatment

2000 ◽  
Vol 279 (6) ◽  
pp. L1120-L1128 ◽  
Author(s):  
Alexandre Trifilieff ◽  
Ahmed El-Hashim ◽  
Claude Bertrand

The kinetics of airway inflammation and remodeling processes following ovalbumin aerosol challenge in sensitized BALB/c mice was studied. Mice were exposed to either single or five ovalbumin challenges over 5 days. In both protocols, time-dependent increases in bronchoalveolar lavage (BAL) cellular fibronectin, neutrophils and eosinophils were observed. The kinetics of these events were similar in both protocols; however, the magnitude of the response was much greater following repeated challenges. BAL protein levels and lymphocyte numbers were increased only following repeated challenges, whereas interleukin (IL)-5 and IL-4 were increased in both protocols. Histological analysis revealed a time-dependent increase in epithelial cell proliferation and in mucus-producing epithelial cells. Proliferation of alveolar cells was observed only following repeated challenges. Airway hyperreactivity was observed in both protocols but was much greater following repeated challenges. Pretreatment with dexamethasone fully inhibited the inflammatory response and airway hyperreactivity but only partially inhibited the remodeling process. These data suggest that glucocorticoids, although potent anti-inflammatory agents, may not be potent in reducing the lung remodeling process associated with asthma.

2013 ◽  
Vol 781-784 ◽  
pp. 1160-1163
Author(s):  
Xiong Zhang ◽  
Jie Yun Sun ◽  
Hong Mei Zhang ◽  
Lu Si ◽  
Yu Li

As a promising prevention and therapeutic intervention in Alzheimer’s disease, natural food dyes curcumin could obviously inhibit the generation of Aβ, but the mechanism is not fully defined. This study aims to investigate the effects of curcumin on the amyloidogenic pathway of APP in vitro. Plasmids APPswe and BACE1-mychis were transiently co-transfected into SH-SY5Y and HEK293 cells. Then, they were treated with curcumin at 0, 1.25, 5, 20 μmol/L for 24 h, or with curcumin at 5μmol/L for 0, 12, 24 and 48 h for the time course assay. Our findings showed that curcumin could inhibit the expression of the APP at mRNA level; the expression of the BACE1 and C99 at mRNA and protein levels, furthermore it could inhibit the generation of Aβ40/42, and those changes were dose-time dependent (p<0.05). Our study indicates that Aβ40/42 generation inhibition effect of curcumin might due to its influence on amyloidogenic pathway. This may provide important experimental basis for AD treatment with curcumin.


2011 ◽  
Vol 55 (9) ◽  
pp. 4469-4474 ◽  
Author(s):  
Wang Hengzhuang ◽  
Hong Wu ◽  
Oana Ciofu ◽  
Zhijun Song ◽  
Niels Høiby

ABSTRACTThe time course of activity of colistin and imipenem against mucoid and nonmucoidPseudomonas aeruginosagrowing in a biofilm showed that compared with those for planktonic bacteria, the kinetics of colistin and imipenem retained the concentration- and time-dependent killing, respectively, but higher doses of antibiotics and longer dosing periods were required for biofilm eradication. Biofilms of mucoidP. aeruginosawere more difficult to eradicate than nonmucoid biofilms.


1998 ◽  
Vol 37 (03) ◽  
pp. 107-112 ◽  
Author(s):  
I. Lauer ◽  
M. Bähre ◽  
E. Richter ◽  
B. Melier

Summary Aim: In 214 patients with benign thyroid diseases the time-course of urinary iodine excretion (UIE) was investigated in order to identify changes after radioiodine therapy (RITh). Method: UIE was measured photometrically (cerium-arsenite method) and related to urinary creatinine on the first and last day of the radioiodine test and then three days, seven days, four weeks, and six months after 1311 administration. Results: As compared with the level found immediately before radioiodine therapy, median UIE had almost doubled four weeks after therapy and was still significantly elevated six months after therapy. This increase correlated significantly with the target volume as measured by scintigraphy and sonography. Conclusions: The persistent elevation of UIE for months after RITh is a measure of treatment-induced damage to thyrocytes. Therefore, in view of the unfavourable kinetics of iodine that follow it, RITh should if possible be given via a single-dose regime.


Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1652
Author(s):  
Chinmaya Panda ◽  
Clara Voelz ◽  
Pardes Habib ◽  
Christian Mevissen ◽  
Thomas Pufe ◽  
...  

Intra-neuronal misfolding of monomeric tau protein to toxic β-sheet rich neurofibrillary tangles is a hallmark of Alzheimer’s disease (AD). Tau pathology correlates not only with progressive dementia but also with microglia-mediated inflammation in AD. Amyloid-beta (Aβ), another pathogenic peptide involved in AD, has been shown to activate NLRP3 inflammasome (NOD-like receptor family, pyrin domain containing 3), triggering the secretion of proinflammatory interleukin-1β (IL1β) and interleukin-18 (IL18). However, the effect of tau protein on microglia concerning inflammasome activation, microglial polarization, and autophagy is poorly understood. In this study, human microglial cells (HMC3) were stimulated with the unaggregated and aggregated forms of the tau-derived PHF6 peptide (VQIVYK). Modulation of NLRP3 inflammasome was examined by qRT-PCR, immunocytochemistry, and Western blot. We demonstrate that fibrillar aggregates of VQIVYK upregulated the NLRP3 expression at both mRNA and protein levels in a dose- and time-dependent manner, leading to increased expression of IL1β and IL18 in HMC3 cells. Aggregated PHF6-peptide also activated other related inflammation and microglial polarization markers. Furthermore, we also report a time-dependent effect of the aggregated PHF6 on BECN1 (Beclin-1) expression and autophagy. Overall, the PHF6 model system-based study may help to better understand the complex interconnections between Alzheimer’s PHF6 peptide aggregation and microglial inflammation, polarization, and autophagy.


1984 ◽  
Vol 160 (3) ◽  
pp. 877-892 ◽  
Author(s):  
G Lamson ◽  
M E Koshland

The time course of differentiative events in the pentamer IgM response was examined by following the expression of J chain and mu chain RNA and their protein products in mitogen-stimulated lymphocytes. The analyses showed that the shift to mus RNA synthesis begins shortly after stimulation and precedes proliferation of the cells and any increase in mu RNA levels. In contrast, expression of J chain RNA and the amplification of J chain and mus message are late events that coincide with a phase of rapid proliferation and with the secretion of pentamer IgM antibody. The kinetics of J and mu chain RNA expression observed in normal lymphocytes were supported by analyses of lymphoid cell lines. B lymphomas were found to display the RNA pattern characteristic of early-activated lymphocytes, i.e., a partial shift to mus RNA production and no J chain RNA, whereas IgM-secreting lines resembled late-activated lymphocytes in their expression of high levels of both mus and J chain mRNA. Moreover, the kinetics of J and mus chain RNA expression correlates with the sequential action of B cell lymphokines in the induction of the pentamer IgM response. This correlation suggests that the successive differentiative changes are triggered by successive membrane stimuli.


2015 ◽  
Vol 3 (1) ◽  
pp. 144-150 ◽  
Author(s):  
J. Nordmann ◽  
S. Buczka ◽  
B. Voss ◽  
M. Haase ◽  
K. Mummenhoff

We have investigated the kinetics of the uptake and the translocation of nanoparticles of different size in plants.


1988 ◽  
Vol 8 (5) ◽  
pp. 1957-1969 ◽  
Author(s):  
R A Shapiro ◽  
D Herrick ◽  
R E Manrow ◽  
D Blinder ◽  
A Jacobson

As an approach to understanding the structures and mechanisms which determine mRNA decay rates, we have cloned and begun to characterize cDNAs which encode mRNAs representative of the stability extremes in the poly(A)+ RNA population of Dictyostelium discoideum amoebae. The cDNA clones were identified in a screening procedure which was based on the occurrence of poly(A) shortening during mRNA aging. mRNA half-lives were determined by hybridization of poly(A)+ RNA, isolated from cells labeled in a 32PO4 pulse-chase, to dots of excess cloned DNA. Individual mRNAs decayed with unique first-order decay rates ranging from 0.9 to 9.6 h, indicating that the complex decay kinetics of total poly(A)+ RNA in D. discoideum amoebae reflect the sum of the decay rates of individual mRNAs. Using specific probes derived from these cDNA clones, we have compared the sizes, extents of ribosome loading, and poly(A) tail lengths of stable, moderately stable, and unstable mRNAs. We found (i) no correlation between mRNA size and decay rate; (ii) no significant difference in the number of ribosomes per unit length of stable versus unstable mRNAs, and (iii) a general inverse relationship between mRNA decay rates and poly(A) tail lengths. Collectively, these observations indicate that mRNA decay in D. discoideum amoebae cannot be explained in terms of random nucleolytic events. The possibility that specific 3'-structural determinants can confer mRNA instability is suggested by a comparison of the labeling and turnover kinetics of different actin mRNAs. A correlation was observed between the steady-state percentage of a given mRNA found in polysomes and its degree of instability; i.e., unstable mRNAs were more efficiently recruited into polysomes than stable mRNAs. Since stable mRNAs are, on average, "older" than unstable mRNAs, this correlation may reflect a translational role for mRNA modifications that change in a time-dependent manner. Our previous studies have demonstrated both a time-dependent shortening and a possible translational role for the 3' poly(A) tracts of mRNA. We suggest, therefore, that the observed differences in the translational efficiency of stable and unstable mRNAs may, in part, be attributable to differences in steady-state poly(A) tail lengths.


Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Christopher M. Mayer ◽  
Denise D. Belsham

Abstract Central insulin signaling is critical for the prevention of insulin resistance. Hyperinsulinemia contributes to insulin resistance, but it is not yet clear whether neurons are subject to cellular insulin resistance. We used an immortalized, hypothalamic, clonal cell line, mHypoE-46, which exemplifies neuronal function and expresses the components of the insulin signaling pathway, to determine how hyperinsulinemia modifies neuronal function. Western blot analysis indicated that prolonged insulin treatment of mHypoE-46 cells attenuated insulin signaling through phospho-Akt. To understand the mechanisms involved, time-course analysis was performed. Insulin exposure for 4 and 8 h phosphorylated Akt and p70-S6 kinase (S6K1), whereas 8 and 24 h treatment decreased insulin receptor (IR) and IR substrate 1 (IRS-1) protein levels. Insulin phosphorylation of S6K1 correlated with IRS-1 ser1101 phosphorylation and the mTOR-S6K1 pathway inhibitor rapamycin prevented IRS-1 serine phosphorylation. The proteasomal inhibitor epoxomicin and the lysosomal pathway inhibitor 3-methyladenine prevented the degradation of IRS-1 and IR by insulin, respectively, and pretreatment with rapamycin, epoxomicin, or 3-methyladenine prevented attenuation of insulin signaling by long-term insulin exposure. Thus, a sustained elevation of insulin levels diminishes neuronal insulin signaling through mTOR-S6K1-mediated IRS-1 serine phosphorylation, proteasomal degradation of IRS-1 and lysosomal degradation of the IR.


1990 ◽  
Vol 112 (4) ◽  
pp. 437-443 ◽  
Author(s):  
Shou-Yan Lee ◽  
G. W. Schmid-Scho¨nbein

Although blood flow in the microcirculation of the rat skeletal muscle has negligible inertia forces with very low Reynolds number and Womersley parameter, time-dependent pressure and flow variations can be observed. Such phenomena include, for example, arterial flow overshoot following a step arterial pressure, a gradual arterial pressure reduction for a step flow, or hysteresis between pressure and flow when a pulsatile pressure is applied. Arterial and venous flows do not follow the same time course during such transients. A theoretical analysis is presented for these phenomena using a microvessel with distensible viscoelastic walls and purely viscous flow subject to time variant arterial pressures. The results indicate that the vessel distensibility plays an important role in such time-dependent microvascular flow and the effects are of central physiological importance during normal muscle perfusion. In-vivo whole organ pressure-flow data in the dilated rat gracilis muscle agree in the time course with the theoretical predictions. Hemodynamic impedances of the skeletal muscle microcirculation are investigated for small arterial and venous pressure amplitudes superimposed on an initial steady flow and pressure drop along the vessel.


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