scholarly journals High Molecular Weight Hyaluronan Suppresses Macrophage M1 Polarization and Enhances IL-10 Production in PM2.5-Induced Lung Inflammation

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1766 ◽  
Author(s):  
Qiwen Shi ◽  
Lan Zhao ◽  
Chenming Xu ◽  
Leifang Zhang ◽  
Hang Zhao

PM2.5 is particulate matter with a diameter of 2.5 μm or less. Airway macrophages are the key players regulating PM2.5-induced inflammation. High molecular weight hyaluronan (HMW-HA) has previously been shown to exert protective effects on PM2.5-induced acute lung injury and inflammation. However, little is known about the detailed mechanism. In this study, we aimed to determine whether HMW-HA alleviates PM2.5-induced pulmonary inflammation by modulating macrophage polarization. The levels of M1 biomarkers TNF-α, IL-1β, IL-6, CXCL1, CXCL2, NOS2 and CD86, as well as M2 biomarkers IL-10, MRC1, and Arg-1 produced by macrophages were measured by ELISA, qPCR, and flow cytometry. In addition, the amount of M1 macrophages in lung tissues was examined by immunofluorescence of CD68 and NOS2. We observed a decline in PM2.5-induced M1 polarization both in macrophages and lung tissues when HMW-HA was administered simultaneously. Meanwhile, western blot analysis revealed that PM2.5-induced JNK and p38 phosphorylation was suppressed by HMW-HA. Furthermore, in vitro and in vivo studies showed that co-stimulation with HMW-HA and PM2.5 promoted the expression and release of IL-10, but exhibited limited effects on the transcription of MRC1 and ARG1. In conclusion, our results demonstrated that HMW-HA ameliorates PM2.5-induced lung inflammation by repressing M1 polarization through JNK and p38 pathways and promoting the production of pro-resolving cytokine IL-10.

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.


2021 ◽  
Author(s):  
Huiwen Tian ◽  
Shumei Lin ◽  
Jing Wu ◽  
Ming Ma ◽  
Jian Yu ◽  
...  

Abstract Corneal transplantation rejection remains a major threat to the success rate in high-risk patients. Given the many side effects presented by traditional immunosuppressants, there is an urgency to clarify the mechanism of corneal transplantation rejection and to identify new therapeutic targets. Kaempferol is a natural flavonoid that has been proven in various studies to possess anti-inflammatory, antioxidant, anticancer, and neuroprotective properties. However, the relationship between kaempferol and corneal transplantation remains largely unexplored. To address this, both in vivo and in vitro, we established a model of corneal allograft transplantation in Wistar rats and an LPS-induced inflammatory model in THP-1 derived human macrophages. In the transplantation experiments, we observed an enhancement in the NLRP3 / IL-1 β axis and in M1 macrophage polarization post-operation. In groups to which kaempferol intraperitoneal injections were administered, this response was effectively reduced. However, the effect of kaempferol was reversed after the application of autophagy inhibitors. Similarly, in the inflammatory model, we found that different concentrations of kaempferol can reduce the LPS-induced M1 polarization and NLRP3 inflammasome activation. Moreover, we confirmed that kaempferol induced autophagy and that autophagy inhibitors reversed the effect in macrophages. In conclusion, we found that kaempferol can inhibit the activation of the NLRP3 inflammasomes by inducing autophagy, thus inhibiting macrophage polarization, and ultimately alleviating corneal transplantation rejection. Thus, our study suggests that kaempferol could be used as a potential therapeutic agent in the treatment of allograft rejection.


1988 ◽  
Vol 2 (1) ◽  
pp. 7-11 ◽  
Author(s):  
T. Nagakura ◽  
T. Onda ◽  
Y. likura ◽  
T. Endo ◽  
H. Nagakura ◽  
...  

High molecular weight neutrophil chemotactic activity has been identified in resected human nasal polyps, inferior turbinates, and nasal secretions following antigen challenge. The estimated molecular weight, by gel filtration chromatography, was approximately 600,000. However, a heterogeneity of molecular weight in some patients was recognized. Our results suggest a possible role for high molecular weight-neutrophil chemotactic activity in the pathogenesis of hypersensitivity in the human nasal cavity.


Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 68 ◽  
Author(s):  
Silvia Tores de la Cruz ◽  
Amaia Iriondo-DeHond ◽  
Teresa Herrera ◽  
Yolanda Lopez-Tofiño ◽  
Carlos Galvez-Robleño ◽  
...  

Melanoidins present in coffee silverskin, the only by-product of the roasting process, are formed via the Maillard reaction. The exact structure, biological properties, and mechanism of action of coffee silverskin melanoidins, remain unknown. This research work aimed to contribute to this novel knowledge. To achieve this goal, melanoidins were obtained from an aqueous extract of Arabica coffee silverskin (WO2013004873A1) and was isolated through ultrafiltration (>10 kDa). The isolation protocol was optimized and the chemical composition of the high molecular weight fraction (>10 kDa) was evaluated, by analyzing the content of protein, caffeine, chlorogenic acid, and the total dietary fiber. In addition, the structural analysis was performed by infrared spectroscopy. Antioxidant properties were studied in vitro and the fiber effect was studied in vivo, in healthy male Wistar rats. Melanoidins were administered to animals in the drinking water at a dose of 1 g/kg. At the fourth week of treatment, gastrointestinal motility was evaluated through non-invasive radiographic means. In conclusion, the isolation process was effective in obtaining a high molecular weight fraction, composed mainly of dietary fiber, including melanoidins, with in vitro antioxidant capacity and in vivo dietary fiber effects.


2001 ◽  
Vol 127 (3) ◽  
pp. 1243-1255 ◽  
Author(s):  
Yong-Woo Kim ◽  
Dae-Sup Park ◽  
Seung-Cheol Park ◽  
Sung Hee Kim ◽  
Gang-Won Cheong ◽  
...  

1998 ◽  
Vol 95 (16) ◽  
pp. 9319-9324 ◽  
Author(s):  
Frank S. Lee ◽  
Robert T. Peters ◽  
Luan C. Dang ◽  
Tom Maniatis

A critical step in the signal-induced activation of the transcription factor NF-κB is the site-specific phosphorylation of its inhibitor, IκB, that targets the latter for degradation by the ubiquitin–proteasome pathway. We have previously shown that mitogen-activated protein kinase/ERK kinase kinase 1 (MEKK1) can induce both this site-specific phosphorylation of IκBα at Ser-32 and Ser-36 in vivo and the activity of a high molecular weight IκB kinase complex in vitro. Subsequently, others have identified two proteins, IκB kinase α (IKK-α) and IκB kinase β (IKK-β), that are present in a tumor necrosis factor α-inducible, high molecular weight IκB kinase complex. These kinases are believed to directly phosphorylate IκB based on the examination of the kinase activities of IKK immunoprecipitates, but more rigorous proof of this has yet to be demonstrated. We show herein that recombinant IKK-α and IKK-β can, in fact, directly phosphorylate IκBα at Ser-32 and Ser-36, as well as homologous residues in IκBβ in vitro, and thus are bona fide IκB kinases. We also show that MEKK1 can induce the activation of both IKK-α and IKK-β in vivo. Finally, we show that IKK-α is present in the MEKK1-inducible, high molecular weight IκB kinase complex and treatment of this complex with MEKK1 induces phosphorylation of IKK-α in vitro. We conclude that IKK-α and IKK-β can mediate the NF-κB-inducing activity of MEKK1.


1974 ◽  
Vol 62 (2) ◽  
pp. 355-361 ◽  
Author(s):  
JENNIFER M. DEHNEL ◽  
P. D. McCONAGHEY ◽  
M. J. O. FRANCIS

SUMMARY Plasma somatomedin is the intermediary through which growth hormone (GH) exerts its effects on the growing skeleton. Somatomedin activity may be produced in vitro by perfusion of the liver and kidneys of rats with Waymouth's medium containing GH. The relationship between the activity of plasma somatomedin and somatomedin of hepatic and renal origin has yet to be clarified. Somatomedin from plasma can be separated into active fractions of both high and low molecular weight. Similarly, ultrafiltration of medium containing somatomedin of hepatic origin indicates the existence of two active fractions, one of high molecular weight (greater than 50000) and one of low molecular weight (less than 1000). The latter can be attributed to the release of amino acids, such as serine and glutamine, by the perfused tissue. The high molecular weight fraction is believed to represent GH-dependent somatomedin. Fractions that inhibit production of cartilage matrix are present in liver perfusates as well as in plasma. These results provide further evidence that the liver is a source of GH-dependent somatomedin in vivo. Furthermore, cartilage growth may be controlled not only by the GH-stimulated release of somatomedin by the liver, but also by its release of acid-labile somatomedin inhibitors.


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