scholarly journals Blood-borne fragments of fibronectin after thermal injury

Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 2037-2041 ◽  
Author(s):  
P La Celle ◽  
FA Blumenstock ◽  
TM Saba

Abstract Fibronectin is an adhesive protein that can promote phagocytosis and endothelial cell adhesion. Plasma fibronectin declines following burn in animals and patients, potentially due to its complexing with circulating collagenous debris as well as its rapid binding to sites of tissue injury. Such depletion of fibronectin initiates an opsonic deficiency of the plasma. In view of the sensitivity of fibronectin to proteolytic enzymes, an additional factor that could contribute to the decrease of plasma opsonic activity after burn is the proteolytic fragmentation of fibronectin in the blood. In the current study, we determined if fibronectin fragments appear in the blood of anesthetized rats after a sublethal full-thickness skin burn of 15% to 16% of body surface. Plasma fibronectin concentration was quantified by enzyme- linked immunosorbent assay and the presence of fibronectin fragments in plasma was determined by immunoblot analysis. All blood was collected in an antiprotease mixture to yield final plasma concentrations of 0.15% EDTA, 3mmol/L phenylmethylsulfonyl fluoride, and 3 mmol/L iodoacetate to prevent degradation of fibronectin after sampling. Plasma fibronectin decreased 60% to 70% within 30 minutes post-burn, and this low level lasted for at least 4 hours. Within 30 minutes post- burn, two prominent fragments of fibronectin with a molecular weight of 110 +/- 2.2 kd and 122 +/- 3.3 Kd, respectively, were also detected in the plasma. Peak concentration of these fragments was detected at 60 minutes post-burn, but their level declined by 4 hours. By 4 hours, both bands appeared to resolve into doublets. To rule out the possibility that the fragments of fibronectin detected in the plasma were actually generated by coagulation enzymes activated at the site of peripheral blood sampling, rapid direct inferior vena cava sampling was performed, which also yield the presence of the fragments. Thus, fibronectin fragments exist in the plasma following thermal injury. Because fragments of fibronectin can compete with the intact fibronectin molecule with respect to its ability to stimulate macrophage phagocytosis, such fragments may contribute to altered systemic phagocytic host defense following thermal injury. Furthermore, because fibronectin peptides can compete with matrix fibronectin and impair adhesion of cultured endothelial cells, such circulating fragments may also influence the integrity of the vascular barrier.

Blood ◽  
1991 ◽  
Vol 77 (9) ◽  
pp. 2037-2041
Author(s):  
P La Celle ◽  
FA Blumenstock ◽  
TM Saba

Fibronectin is an adhesive protein that can promote phagocytosis and endothelial cell adhesion. Plasma fibronectin declines following burn in animals and patients, potentially due to its complexing with circulating collagenous debris as well as its rapid binding to sites of tissue injury. Such depletion of fibronectin initiates an opsonic deficiency of the plasma. In view of the sensitivity of fibronectin to proteolytic enzymes, an additional factor that could contribute to the decrease of plasma opsonic activity after burn is the proteolytic fragmentation of fibronectin in the blood. In the current study, we determined if fibronectin fragments appear in the blood of anesthetized rats after a sublethal full-thickness skin burn of 15% to 16% of body surface. Plasma fibronectin concentration was quantified by enzyme- linked immunosorbent assay and the presence of fibronectin fragments in plasma was determined by immunoblot analysis. All blood was collected in an antiprotease mixture to yield final plasma concentrations of 0.15% EDTA, 3mmol/L phenylmethylsulfonyl fluoride, and 3 mmol/L iodoacetate to prevent degradation of fibronectin after sampling. Plasma fibronectin decreased 60% to 70% within 30 minutes post-burn, and this low level lasted for at least 4 hours. Within 30 minutes post- burn, two prominent fragments of fibronectin with a molecular weight of 110 +/- 2.2 kd and 122 +/- 3.3 Kd, respectively, were also detected in the plasma. Peak concentration of these fragments was detected at 60 minutes post-burn, but their level declined by 4 hours. By 4 hours, both bands appeared to resolve into doublets. To rule out the possibility that the fragments of fibronectin detected in the plasma were actually generated by coagulation enzymes activated at the site of peripheral blood sampling, rapid direct inferior vena cava sampling was performed, which also yield the presence of the fragments. Thus, fibronectin fragments exist in the plasma following thermal injury. Because fragments of fibronectin can compete with the intact fibronectin molecule with respect to its ability to stimulate macrophage phagocytosis, such fragments may contribute to altered systemic phagocytic host defense following thermal injury. Furthermore, because fibronectin peptides can compete with matrix fibronectin and impair adhesion of cultured endothelial cells, such circulating fragments may also influence the integrity of the vascular barrier.


Blood ◽  
1990 ◽  
Vol 75 (2) ◽  
pp. 470-478 ◽  
Author(s):  
P La Celle ◽  
FA Blumenstock ◽  
C McKinley ◽  
TM Saba ◽  
PA Vincent ◽  
...  

Abstract Plasma fibronectin augments the clearance of blood-borne foreign and effete complexes by mononuclear phagocytes. The release of a “gelatin- like” ligand into plasma after thermal injury has been reported. We quantified the release of this collagenous debris from thermally injured skin, and its potential interaction with soluble fibronectin in plasma using anesthetized rats. Collagen-like material debris in the plasma was detected by assay of hydroxyproline. Fibronectin was measured by a double antibody enzyme-linked immunosorbent assay (ELISA) technique. Over a 24-hour postburn interval, plasma hydroxyproline increased from 6.7 +/- 0.6 micrograms/mL to a maximum of 19.0 +/- 3.3 micrograms/mL at 60 minutes postburn, and normalized by 6 hours. A direct correlation existed between the magnitude of burn injury and the increase in plasma hydroxyproline. In parallel, plasma fibronectin declined over a 15-minute to 2-hour period postburn, and normalized by 3 to 4 hours with rebound hyperfibronectinemia observed at 24 hours. The elevation in total plasma hydroxyproline was not due to an increase in plasma Clq (zero time, 26.2 +/- 1.4 micrograms/mL; 60 minutes, 23.9 +/- 1.1 micrograms/mL). Tracer studies with 125I-fibronectin showed that the acute decline of plasma fibronectin was due to its uptake by the liver and binding to sites of tissue injury. Total hydroxyproline in extracts of burn skin, used as an index of soluble collagenous material, rose from 15 +/- 3.3 micrograms/g skin at zero time to 129.3 +/- 43.7 micrograms/g skin by 5 minutes postburn, with a decline to 38 +/- 22 micrograms/g skin by 24 hours. The formation of circulating fibronectin-gelatin complexes in vivo was documented by cross- immunoelectrophoresis coupled with autoradiography using 125I-gelatin as a model ligand. Thus, collagenous tissue debris from burned skin may enter the plasma after thermal injury and directly complexes with soluble fibronectin before hepatic phagocytic clearance.


Blood ◽  
1990 ◽  
Vol 75 (2) ◽  
pp. 470-478
Author(s):  
P La Celle ◽  
FA Blumenstock ◽  
C McKinley ◽  
TM Saba ◽  
PA Vincent ◽  
...  

Plasma fibronectin augments the clearance of blood-borne foreign and effete complexes by mononuclear phagocytes. The release of a “gelatin- like” ligand into plasma after thermal injury has been reported. We quantified the release of this collagenous debris from thermally injured skin, and its potential interaction with soluble fibronectin in plasma using anesthetized rats. Collagen-like material debris in the plasma was detected by assay of hydroxyproline. Fibronectin was measured by a double antibody enzyme-linked immunosorbent assay (ELISA) technique. Over a 24-hour postburn interval, plasma hydroxyproline increased from 6.7 +/- 0.6 micrograms/mL to a maximum of 19.0 +/- 3.3 micrograms/mL at 60 minutes postburn, and normalized by 6 hours. A direct correlation existed between the magnitude of burn injury and the increase in plasma hydroxyproline. In parallel, plasma fibronectin declined over a 15-minute to 2-hour period postburn, and normalized by 3 to 4 hours with rebound hyperfibronectinemia observed at 24 hours. The elevation in total plasma hydroxyproline was not due to an increase in plasma Clq (zero time, 26.2 +/- 1.4 micrograms/mL; 60 minutes, 23.9 +/- 1.1 micrograms/mL). Tracer studies with 125I-fibronectin showed that the acute decline of plasma fibronectin was due to its uptake by the liver and binding to sites of tissue injury. Total hydroxyproline in extracts of burn skin, used as an index of soluble collagenous material, rose from 15 +/- 3.3 micrograms/g skin at zero time to 129.3 +/- 43.7 micrograms/g skin by 5 minutes postburn, with a decline to 38 +/- 22 micrograms/g skin by 24 hours. The formation of circulating fibronectin-gelatin complexes in vivo was documented by cross- immunoelectrophoresis coupled with autoradiography using 125I-gelatin as a model ligand. Thus, collagenous tissue debris from burned skin may enter the plasma after thermal injury and directly complexes with soluble fibronectin before hepatic phagocytic clearance.


2021 ◽  
Vol 10 (7) ◽  
pp. 1436
Author(s):  
Barbara Maria Piskór ◽  
Andrzej Przylipiak ◽  
Emilia Dąbrowska ◽  
Iwona Sidorkiewicz ◽  
Marek Niczyporuk ◽  
...  

Metalloproteinases (MMPs) are a group of proteolytic enzymes involved in the maintenance of a proper structure of extracellular matrix (ECM). Matrilysins (MMP-7 and MMP-26) are members of the MMPs group that show promise as potential breast cancer (BC) markers. The aim of the study was to evaluate plasma levels of MMP-7, MMP-26 and CA 15-3 individually and in combination and assess the diagnostic utility of studied matrilysins in patients with BC. The study group consisted of 120 patients with BC, and the control group consisted of 40 subjects with benign breast cancer and 40 healthy women. Concentrations of MMP-7 and MMP-26 were determined by enzyme-linked immunosorbent assay, and CA 15-3 by chemiluminescent microparticle immunoassay. Plasma levels of MMP-7 were significantly higher in the BC group than in the control group. Concentrations of MMP-26 and CA 15-3 were highest in stages II and IV of the disease. The highest diagnostic sensitivity was observed in stages III and IV BC for the combination of all tested markers (92.5%). The highest diagnostic specificity was noted for all tested parameters combined in the BC group (95.0%). The area under the receiver operating characteristic (ROC) curve (AUC) for the combination of markers (MMP-7+MMP-26+CA 15-3) was the largest (0.9138) in stages III and IV. Individual marker analysis showed that MMP-7 had the highest AUC (0.8894) in advanced stages of the disease. Study results indicate that MMP-7 could be used as an additional marker that would improve the diagnostic utility of CA 15-3 in early stages of BC. Therefore, the combined assessment of MMP-7 and MMP-26 with CA 15-3 might be useful in determining disease progression. Further studies are needed to evaluate whether matrilysins show promise as potential markers for improving the diagnosis of BC.


1986 ◽  
Vol 56 (03) ◽  
pp. 299-301 ◽  
Author(s):  
L J Garcia Frade ◽  
S Poole ◽  
S Hanley ◽  
L J Creighton ◽  
A D Curtis ◽  
...  

SummaryThe bioavailability of human recombinant tissue plasminogen activator (rt-PA) in rats was measured after subcutaneous (s.c.) and intramuscular (i.m.) injection. Rt-PA was absorbed after both i.m. and s.c. injection, giving peak plasma concentrations within 30 min and 1 h, respectively, with detectable concentrations up to 6 h. These peak values of bioavailable t-PA were obtained in a functional fibrin plate assay of euglobulin precipitates and expressed as +88% and +243% (for s.c. and i.m. routes respectively) above basal rat fibrinolytic activity. Prior injection of rt-PA, s.c. or i.m., significantly reduced the weights of thrombi induced in the inferior vena cava after injection.


Blood ◽  
2019 ◽  
Vol 133 (9) ◽  
pp. 978-989 ◽  
Author(s):  
Krystin Krauel ◽  
Patricia Preuße ◽  
Theodore E. Warkentin ◽  
Catja Trabhardt ◽  
Sven Brandt ◽  
...  

Abstract Heparin-induced thrombocytopenia (HIT) is caused by platelet-activating anti–platelet factor 4 (PF4)/heparin antibodies. Platelet activation assays that use “washed” platelets are more sensitive for detecting HIT antibodies than platelet-rich plasma (PRP)–based assays. Moreover, heparin-exposed patients vary considerably with respect to the risk of PF4/heparin immunization and, among antibody-positive patients, the risk of subsequent “breakthrough” of clinical HIT with manifestation of thrombocytopenia. We used washed platelets and PRP, standard laboratory HIT tests, and physicochemical methods to identify a plasma factor interfering with PF4/heparin complexes and anti-PF4/heparin antibody–platelet interaction, thus explaining differences in functional assays. To investigate a modulating risk for PF4/heparin immunization and breakthrough of HIT, we also tested 89 plasmas from 2 serosurveillance trials. Fibronectin levels were measured in 4 patient groups exhibiting different degrees of heparin-dependent immunization and expression of HIT. The heat-labile plasma protein, fibronectin, inhibited PF4 binding to platelets in a dose-dependent fashion, particularly in washed (vs PRP) systems. Fibronectin also inhibited PF4/heparin binding to platelets, anti-PF4/heparin antibody binding to PF4/heparin complexes, and anti-PF4/heparin antibody–induced platelet activation as a result of PF4/heparin complex disruption. In addition, plasma fibronectin levels increased progressively among the following 4 patient groups: enzyme-linked immunosorbent assay (ELISA)+/serotonin-release assay (SRA)+/HIT+ < ELISA+/SRA+/HIT− ∼ ELISA+/SRA−/HIT− < ELISA−/SRA−/HIT−. Altogether, these findings suggest that fibronectin interferes with PF4/heparin complex formation and anti-PF4/heparin antibody–induced platelet activation. Reduced fibronectin levels in washed platelet assays help to explain the greater sensitivity of washed platelet (vs PRP) assays for HIT. More importantly, lower plasma fibronectin levels could represent a risk factor for PF4/heparin immunization and clinical breakthrough of HIT.


Author(s):  
Sophia Sakka ◽  
Tania Siahanidou ◽  
Chronis Voyatzis ◽  
Panagiota Pervanidou ◽  
Christina Kaminioti ◽  
...  

AbstractObesity and cardiovascular disease (CVD) often co-exist, but the pathophysiologic mechanisms that link the two are not fully understood. Lipoprotein-associated phospholipase ASixty-seven lean [39 boys and 28 girls, mean body mass index (BMI) z-score –0.2±0.8] and 66 obese (32 boys and 34 girls, mean BMI z-score 4.4±1.2) age-matched (p=0.251) children, aged 6–12 years, were studied. BMI z-score was calculated based on the Greek BMI growth curves, and children were categorized as obese according to the Cole criteria. All children underwent physical examination and a fasting morning blood sample was obtained for glucose, insulin, lipid profile, and Lp-PLA2 assessment. Plasma concentrations of Lp-PLA2 were determined by a commercially available Lp-PLA2 enzyme-linked immunosorbent assay kit (PLAC Test), while other measurements were performed using standard methods.Plasma Lp-PLA2 levels were significantly higher in obese children (322.5±77.8 ng/mL) compared with normal-weight ones (278.0±64.4 ng/mL, p<0.001). Lp-PLA2 concentrations were significantly correlated with the BMI z-score (p=0.004). Receiver operating characteristic analysis on Lp-PLA2 values resulted in significant areas under the curve (AUC) for distinguishing between obese and normal-weight groups of children (AUC, 0.726; p<0.001).We found significantly higher Lp-PLA2 levels in obese children than lean controls. Interestingly, they all had levels >200 ng/mL, which are considered to correlate with atherosclerosis and a high thromboembolic risk in adults. The positive correlation of Lp-PLA2 with BMI suggests that Lp-PLA2 might be the link between obesity and increased cardiovascular risk, which can be elevated even at a very young age. Measurement of Lp-PLA2 in plasma could therefore represent a further biomarker for assessing increased CVD risk in obese children and adolescents.


2020 ◽  
Vol 40 (12) ◽  
Author(s):  
Shunwan Jiang ◽  
Zhi Chen ◽  
Wenqiang Lai ◽  
Qingchun Mai ◽  
Dayu Chen ◽  
...  

Abstract Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial for alleviation of inflammation-related diseases. The objective of the present study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague–Dawley (SD) rats with hammer beating served as the in vivo models of acute STI. Hematoxylin–Eosin (HE) staining was used for histopathology assessment. The levels of inflammatory factors, including prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1t and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). Human dermal microvascular endothelium cell line HMEC-1 and rat vascular endothelium cell line RAOEC were used to explore the mechanism in vitro. Luciferase gene reporter assay was applied to determine the relationship between miR-26b-5p and Cyclo-oxygenase 2 (COX2). The results showed that HDBD intervention significantly reduced the temperature difference between the healthy side and affected side of rats with hammer beating, together with the decreased levels of COX2, PGE2, TNF-α, IL-6 and IL-1β, and the increased level of miR-26b-5p. In mechanism, miR-26b-5p targeted COX2 and decreased its expression, leading to significant decreases in the levels of PGE2, TNF-α and IL-6 in RAOEC and HMEC-1 cells. In addition, miR-26b-5p inhibition impaired the effects of HDBD on the suppression of PGE2, TNF-α, IL-6 and IL-1β in vitro. In conclusion, the present study revealed that HDBD relieved acute STI via modulating miR-26b-5p/COX2 axis to inhibit inflammation.


2020 ◽  
Author(s):  
Tadeusz Kaminski ◽  
Marta Kiezun ◽  
Ewa Zaobidna ◽  
Kamil Dobrzyń ◽  
Barbara Wasilewska ◽  
...  

Abstract BackgroundVisfatin exists in two forms: the intracellular form which is a rate limiting enzyme engaged in nicotinamide adenine dinucleotide biosynthesis and the extracellular form considered as an adipokine, produced mainly by the adipose tissue. Visfatin could be an energy sensor involved in regulating female fertility, which creates a hormonal link integrating the control of energy homeostasis and reproduction. MethodsThe study compares the expression levels of visfatin gene (quantitative real time PCR) and protein (Western blotting and fluorescent immunohistochemistry) in the selected areas of the porcine hypothalamus responsible for gonadotropin releasing hormone synthesis: the mediobasal hypothalamus (MBH) and preoptic area (POA), and visfatin concentrations in the blood plasma (enzyme-linked immunosorbent assay). The tissue samples were harvested from gilts on days 2-3, 10-12, 14-16 and 17-19 of the estrous cycle, and on days 10-11, 12-13, 15-16, 27-28 of pregnancy. Differences between groups were analyzed by one-way ANOVA followed by Tukey’s post hoc test. ResultsDuring the estrous cycle, visfatin mRNA expression in the MBH was higher on days 2-3 and 17-19, while the visfatin protein concentration on days 17-19. During early pregnancy, the most pronounced gene and protein expression in the MBH was found on days 15-16 and 10-11, respectively. In the POA during the estrous cycle, visfatin gene expression was the highest on days 17-19, and the protein level of visfatin on days 14-16. During early pregnancy, the highest expression of visfatin gene in the POA was observed on days 15-16, whereas the protein concentrations on days 27-28. Blood plasma concentrations of visfatin during the estrous cycle were higher on days 2-3 in relation to other studied phases of the cycle. During early pregnancy, the highest visfatin contents in the blood plasma were observed on days 12-13. Visfatin gene and protein expression in MBH and POA, and visfatin plasma concentrations differed during early pregnancy in relation to days 10-12 of the cycle. ConclusionsThis study demonstrated visfatin expression in the porcine hypothalamus and its dependence on hormonal milieu related to the estrous cycle and early pregnancy.


2009 ◽  
Vol 55 (11) ◽  
pp. 1977-1983 ◽  
Author(s):  
Omar F Laterza ◽  
Lee Lim ◽  
Philip W Garrett-Engele ◽  
Katerina Vlasakova ◽  
Nagaraja Muniappa ◽  
...  

Abstract Background: MicroRNAs (miRNAs) are endogenous, small noncoding RNAs. Because of their size, abundance, tissue specificity, and relative stability in plasma, miRNAs hold promise as unique accessible biomarkers to monitor tissue injury. Methods: We investigated the use of liver-, muscle- and brain-specific miRNAs as circulating biomarkers of tissue injury. We used a highly sensitive quantitative PCR assay to measure specific miRNAs (miR-122, miR-133a, and miR-124) in plasma samples from rats treated with liver or muscle toxicants and from a rat surgical model of stroke. Results: We observed increases in plasma concentrations of miR-122, miR-133a, and miR-124 corresponding to injuries in liver, muscle, and brain, respectively. miR-122 and miR-133a illustrated specificity for liver and muscle toxicity, respectively, because they were not detectable in the plasma of animals with toxicity to the other organ. This result contrasted with the results for alanine aminotransferase (ALT) and aspartate aminotransferase, which were both increased with either organ toxicity. Furthermore, miR-122 exhibited a diagnostic sensitivity superior to that of ALT when the results were correlated to the liver histopathologic results. The miR-124 concentration increased in the plasma of rats 8 h after surgery to produce brain injury and peaked at 24 h, while the miR-122 and miR-133a concentrations remained at baseline values. Conclusions: These results demonstrate that tissue-specific miRNAs may serve as diagnostically sensitive plasma biomarkers of tissue injury.


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