Phosphocholine reverses inhibition of pulmonary surfactant adsorption caused by C-reactive protein

1995 ◽  
Vol 269 (4) ◽  
pp. L492-L497 ◽  
Author(s):  
T. M. McEachren ◽  
K. M. Keough
Keyword(s):  
Pulmonary Surfactant ◽  
Water Soluble ◽  
Molar Ratio ◽  
Surfactant Adsorption ◽  
Dependent Manner ◽  
Water Interface ◽  
C Reactive Protein ◽  
Molar Ratios ◽  
Reactive Protein ◽  
Air Water Interface

The influence of the acute inflammatory phase protein human C-reactive protein (CRP) on the adsorption of porcine pulmonary surfactant from a subphase into an air-water interface has been investigated. CRP was shown to detract from the ability of surfactant to rapidly adsorb to the air-water interface at a molar ratio of 0.03:1 (protein:phospholipid) (weight ratio, 0.5:1). On a weight basis, CRP was found to be more effective than fibrinogen at reducing the adsorption rate of surfactant. The effect of CRP required the presence of calcium and was reversed by the addition of phosphocholine in a concentration-dependent manner. The inhibition of surfactant adsorption by CRP was effectively eliminated by the addition of phosphocholine at a molar ratio of 300:1 (phosphocholine:CRP), but it was not diminished by the addition of identical molar ratios of o-phosphoethanolamine or DL-alpha-glycerophosphate at the same molar ratios. These data suggest that the potent inhibition of surfactant adsorption by CRP is primarily a result of a specific interaction between CRP and the phosphocholine headgroup of surfactant lipids in the subphase and that it can be reversed by the water-soluble CRP ligand, phosphocholine.

From Surface Tension to Molecular Distribution: Modeling Surfactant Adsorption at the Air–Water Interface

Langmuir ◽  
2021 ◽  
Vol 37 (7) ◽  
pp. 2237-2255 ◽  
Author(s):  
Mengsu Peng ◽  
Timothy T. Duignan ◽  
Cuong V. Nguyen ◽  
Anh V. Nguyen
Keyword(s):  
Surface Tension ◽  
Surfactant Adsorption ◽  
Water Interface ◽  
Molecular Distribution ◽  
Distribution Modeling ◽  
Air Water Interface

scholarly journals Fecal Calprotectin, CRP and Leucocytes in IBD Patients: Comparison of Biomarkers With Biopsy Results

2020 ◽  
Author(s):  
Barry D Kyle ◽  
Terence A Agbor ◽  
Shajib Sharif ◽  
Usha Chauhan ◽  
John Marshall ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Fecal Calprotectin ◽  
Dependent Manner ◽  
Ascending Colon ◽  
C Reactive Protein ◽  
Concentration Dependent Manner ◽  
Reactive Protein ◽  
Inflammatory Bowel ◽  
Descending Colon ◽  
Active Inflammation

Abstract Background This study aimed to compare fecal calprotectin (FC) levels with other commonly used parameters as part of patient care during evaluation for inflammatory bowel disease (IBD). Methods We recruited adult IBD patients with ulcerative colitis (UC) and Crohn’s disease (CD) and compared the results of the patient’s biopsy results (i.e., inflamed versus noninflamed) for six sites (i.e., ileum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum) with concentrations of C-reactive protein (CRP), total leucocytes and fecal calprotectin (FC). Results We found that FC was significantly elevated in a concentration-dependent manner that correlated with the number of active inflammation sites reported in biopsy. Although CRP and leucocyte measurements trended upwards in line with inflammation reported from biopsy, the results were highly variable and highlighted poor reliability of these biomarkers for indicating IBD inflammation. Conclusions These results strongly suggest that FC correlates best with biopsy reports and is a superior marker than CRP and leucocytes.

scholarly journals Comprehensive characterization of humic-like substances in smoke PM<sub>2.5</sub> emitted from the combustion of biomass materials and fossil fuels

2016 ◽  
Vol 16 (20) ◽  
pp. 13321-13340 ◽  
Author(s):  
Xingjun Fan ◽  
Siye Wei ◽  
Mengbo Zhu ◽  
Jianzhong Song ◽  
Ping'an Peng
Keyword(s):  
Coal Combustion ◽  
Fossil Fuels ◽  
Solid Phase ◽  
Water Soluble ◽  
Total Carbon ◽  
Atmospheric Environment ◽  
Molar Ratio ◽  
Resonance Spectroscopy ◽  
Molar Ratios ◽  
Biomass Materials

Abstract. Humic-like substances (HULIS) in smoke fine particulate matter (PM2.5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV–vis (ultraviolet–visible) spectroscopy, excitation–emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2–23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0–21.7 and 56.9–66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for  ∼  0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV–vis spectra, a distinct band at λex∕λem ≈  280∕350 nm in EEM spectra, lower H ∕ C and O ∕ C molar ratios, and a high content of [Ar–H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O ∕ C molar ratios (0.43–0.54) and [H–C–O] content (10–19 %), indicating that HULIS from this source mainly consisted of carbohydrate- and phenolic-like structures. HULIS from coal combustion had a lower O ∕ C molar ratio (0.27) and a higher content of [Ar–H] (31 %), suggesting that aromatic compounds were extremely abundant in HULIS from this source. Moreover, the absorption Ångström exponents of primary HULIS from BB and coal combustion were 6.7–8.2 and 13.6, respectively. The mass absorption efficiencies of primary HULIS from BB and coal combustion at 365 nm (MAE365) were 0.97–2.09 and 0.63 m2 gC−1, respectively. Noticeably higher MAE365 values for primary HULIS from BB than coal combustion indicate that the former has a stronger contribution to the light-absorbing properties of aerosols in the atmospheric environment.

Disparate effects of two phosphatidylcholine binding proteins, C-reactive protein and surfactant protein A, on pulmonary surfactant structure and function

2004 ◽  
Vol 287 (6) ◽  
pp. L1145-L1153 ◽  
Author(s):  
Kaushik Nag ◽  
Karina Rodriguez-Capote ◽  
Amiya Kumar Panda ◽  
Laura Frederick ◽  
Stephen A. Hearn ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Amorphous Material ◽  
Protein A ◽  
Surfactant Protein ◽  
Water Soluble ◽  
Surfactant Protein A ◽  
Surface Films ◽  
Inhibitory Effects ◽  
C Reactive Protein ◽  
Reactive Protein

C-reactive protein (CRP) and surfactant protein A (SP-A) are phosphatidylcholine (PC) binding proteins that function in the innate host defense system. We examined the effects of CRP and SP-A on the surface activity of bovine lipid extract surfactant (BLES), a clinically applied modified natural surfactant. CRP inhibited BLES adsorption to form a surface-active film and the film's ability to lower surface tension (γ) to low values near 0 mN/m during surface area reduction. The inhibitory effects of CRP were reversed by phosphorylcholine, a water-soluble CRP ligand. SP-A enhanced BLES adsorption and its ability to lower γ to low values. Small amounts of SP-A blocked the inhibitory effects of CRP. Electron microscopy showed CRP has little effect on the lipid structure of BLES. SP-A altered BLES multilamellar vesicular structure by generating large, loose bilayer structures that were separated by a fuzzy amorphous material, likely SP-A. These studies indicate that although SP-A and CRP both bind PC, there is a difference in the manner in which they interact with surface films.

scholarly journals Microinjection of Ca++-calmodulin causes a localized depolymerization of microtubules.

1983 ◽  
Vol 97 (6) ◽  
pp. 1918-1924 ◽  
Author(s):  
C Keith ◽  
M DiPaola ◽  
F R Maxfield ◽  
M L Shelanski
Keyword(s):  
Mitotic Spindle ◽  
Calcium Ion ◽  
Molar Ratio ◽  
Free Calcium ◽  
Local Concentration ◽  
Dependent Manner ◽  
Calcium Dependent ◽  
Molar Ratios ◽  
Microtubule Polymerization ◽  
Full Complement

The microinjection of calcium-saturated calmodulin into living fibroblasts causes the rapid disruption of microtubules and stress fibers in a sharply delimited region concentric with the injection site. This effect is specific to the calcium-bearing form of calmodulin; neither calcium-free calmodulin nor calcium ion at similar levels affects the cytoskeleton. If cells have previously been microinjected with calcium-free calmodulin, elevation of their intracellular calcium levels to 25 mM potentiates the disruption of microtubules throughout the cytoplasm. Approximately 400 mM free calcium is required to cause an equivalent disruption in uninjected cells. The level of calmodulin necessary to disrupt the full complement of cellular microtubules is found to be approximately in 2:1 molar ratio to tubulin dimer. These results indicate that calmodulin can be localized within the cytoplasm in a calcium-dependent manner and that it can act to regulate the calcium lability of microtubules at molar ratios that could be achieved locally within the cell. Our results are consistent with the hypothesis that calmodulin may be controlling microtubule polymerization equilibria in areas of high local concentration such as the mitotic spindle.

C-reactive protein and inflammation: conformational changes affect function

2015 ◽  
Vol 396 (11) ◽  
pp. 1181-1197 ◽  
Author(s):  
Yi Wu ◽  
Lawrence A. Potempa ◽  
Driss El Kebir ◽  
János G. Filep
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Response ◽  
Host Defense ◽  
Conformational Changes ◽  
Acute Phase Reactant ◽  
Dependent Manner ◽  
C Reactive Protein ◽  
Inflammatory Microenvironment ◽  
Reactive Protein ◽  
Phase Reactant

Abstract The prototypic acute-phase reactant C-reactive protein (CRP) has long been recognized as a useful marker and gauge of inflammation. CRP also plays an important role in host defense against invading pathogens as well as in inflammation. CRP consists of five identical subunits arranged as a cyclic pentamer. CRP exists in at least two conformationally distinct forms, i.e. native pentameric CRP (pCRP) and modified/monomeric CRP (mCRP). These isoforms bind to distinct receptors and lipid rafts, and exhibit distinct functional properties. Dissociation of pCRP into its subunits occurs within the inflammatory microenvironment and newly formed mCRP may then contribute to localizing the inflammatory response. Accumulating evidence indicates that pCRP possesses both pro- and anti-inflammatory actions in a context-dependent manner, whereas mCRP exerts potent pro-inflammatory actions on endothelial cells, endothelial progenitor cells, leukocytes and platelets, and thus may amplify inflammation. Here, we review recent advances that may explain how conformational changes in CRP contribute to shaping the inflammatory response and discuss CRP isomers as potential therapeutic targets to dampen inflammation.

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