| 1. |
- Changhui, Yu, et al.
(author)
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Platelet-Derived CCL5 Regulates CXC Chemokine Formation and Neutrophil Recruitment in Acute Experimental Colitis.
- 2016
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In: Journal of Cellular Physiology. - : Wiley. - 1097-4652 .- 0021-9541. ; 231:2, s. 370-376
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Journal article (peer-reviewed)abstract
- Accumulating data suggest that platelets not only regulate thrombosis and haemostasis but also inflammatory processes. Platelets contain numerous potent pro-inflammatory compounds, including the chemokines CCL5 and CXCL4 although their role in acute colitis remains elusive. The aim of this study was to examine the role of platelets and platelet-derived chemokines in acute colitis. Acute colitis was induced in female Balb/c mice by administration of 5% dextran sodium sulphate (DSS) for five days. Animals received a platelet-depleting, anti-CCL5, anti-CXCL4 or a control antibody prior to DSS challenge. Colonic tissue was collected for quantification of myeloperoxidase (MPO) activity, CXCL5, CXCL2, interleukin-6 (IL-6) and CCL5 levels as well as morphological analyses. Platelet depletion reduced tissue damage and clinical disease activity index in DSS-exposed animals. Platelet depletion not only reduced levels of CXCL2 and CXCL5 but also levels of CCL5 in the inflamed colon. Immunoneutralization of CCL5 but not CXCL4 reduced tissue damage, CXC chemokine expression and neutrophil recruitment in DSS-treated animals. These findings show that platelets play a key role in acute colitis by regulating CXC chemokine generation, neutrophil infiltration and tissue damage in the colon. Moreover, our results suggest that platelet-derived CCL5 is an important link between platelet activation and neutrophil recruitment in acute colitis. This article is protected by copyright. All rights reserved.
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| 2. |
- Zhang, Songen, et al.
(author)
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STAT3-dependent CXC chemokine formation and neutrophil migration in Streptococcal M1 protein-induced acute lung inflammation.
- 2015
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In: American Journal of Physiology: Lung Cellular and Molecular Physiology. - : American Physiological Society. - 1522-1504 .- 1040-0605. ; 308:11, s. 1159-1167
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Journal article (peer-reviewed)abstract
- Streptococcus pyogenes cause infections ranging from mild pharyngitis to severe streptococcal toxic shock syndrome (STSS). The M1 serotype of Streptococcus pyogenes is most frequently associated with STSS. Herein, it was hypothesized that STAT3 signaling might be involved in M1 protein-evoked lung inflammation. The STAT3 inhibitor, S3I-201, was administered to male C57Bl/6 mice before i.v. challenge with M1 protein. Bronchoalveolar fluid and lung tissue were harvested for quantification of STAT3 activity, neutrophil recruitment, edema and CXC chemokine formation. Neutrophil expression of Mac-1 was quantified by use of flow cytometry. Levels of IL-6 and HMGB1 were determined in plasma. CXCL2-induced neutrophil chemotaxis was studied in vitro. Administration of S3I-201 markedly reduced M1 protein-provoked STAT3 activity, neutrophil recruitment, edema formation and inflammatory changes in the lung. In addition, M1 protein significantly increased Mac-1 expression on neutrophils and CXC chemokine levels in the lung. Treatment with S3I-201 had no effect on M1 protein-induced expression of Mac-1 on neutrophils. In contrast, inhibition of STAT3 activity greatly reduced M1 protein-induced formation of CXC chemokines in the lung. Interestingly, STAT3 inhibition markedly decreased plasma levels of IL-6 and HMGB1 in animals exposed to M1 protein. Moreover, we found that S3I-201 abolished CXCL2-induced neutrophil migration in vitro. In conclusion, these novel findings indicate that STAT3 signaling plays a key role in mediating CXC chemokine production and neutrophil infiltration in M1 protein-induced acute lung inflammation.
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| 3. |
- Zhang, Songen, et al.
(author)
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Streptococcal M1 protein triggers chemokine formation, neutrophil infiltration, and lung injury in an NFAT-dependent manner.
- 2015
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In: Journal of Leukocyte Biology. - 1938-3673. ; 97:6, s. 1003-1010
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Journal article (peer-reviewed)abstract
- Streptococcus pyogenes of the M1 serotype can cause STSS, which is associated with significant morbidity and mortality. The purpose of the present study was to examine the role of NFAT signaling in M1 protein-induced lung injury. NFAT-luc mice were treated with the NFAT inhibitor A-285222 before administration of the M1 protein. Neutrophil infiltration, edema, and CXC chemokines were quantified in the lung, 4 h after challenge with the M1 protein. Flow cytometry was used to determine Mac-1 expression. Challenge with the M1 protein increased NFAT-dependent transcriptional activity in the lung, spleen, and liver in NFAT-luc mice. Administration of the NFAT inhibitor A-285222 abolished M1 protein-evoked NFAT activation in the lung, spleen, and liver. M1 protein challenge induced neutrophil recruitment, edema, and CXC chemokine production in the lung, as well as up-regulation of Mac-1 on circulating neutrophils. Inhibition of NFAT activity attenuated M1 protein-induced neutrophil infiltration by 77% and edema formation by 50% in the lung. Moreover, administration of A-285222 reduced M1 protein-evoked pulmonary formation of CXC chemokine >80%. In addition, NFAT inhibition decreased M1 protein-triggered Mac-1 up-regulation on neutrophils. These findings indicate that NFAT signaling controls pulmonary infiltration of neutrophils in response to streptococcal M1 protein via formation of CXC chemokines and neutrophil expression of Mac-1. Thus, the targeting of NFAT activity might be a useful way to ameliorate lung injury in streptococcal infections.
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