Interleukin-6 and the Lung
Jason Kelley in Cytokines of the Lung, 2022
In response to infection, trauma, and malignancy, and in association with several immunological disorders, elevations in body temperature, increased vascular permeability, negative nitrogen balance, and alterations in plasma metal ion concentrations occur (Sehgal, 1990). These changes are accompanied by an increase in hepatic amino acid, zinc, and iron uptake and alterations in hepatic production of acute-phase reactant proteins (Baumann and Gauldie, 1990). The acute-phase proteins are involved in various aspects of the organism’s attempt to control and sequester infection and limit the tissue damage that occurs as a result of the primary immune response. An important characteristic of the acute-phase response is that it is elicited by injury or infection at a localized site in the body, implying that soluble factors produced at local sites of injury are able to act at a distance to alter hepatic function.
Evaluation of the Dermal Irritancy of Chemicals
David W. Hobson in Dermal and Ocular Toxicology, 2020
The majority of acute phase proteins is synthesized in hepatocytes, under the influence of circulating mediators released in association with inflammation and necrosis, and, during acute inflammatory processes, the extent of the acute phase response has a quantitative relationship with the degree of inflammation.90 The acute phase response is observed not only in man, but in all mammals, as well as birds, although the major acute phase proteins vary between species. While in the human, CRP and SAA represent the major acute phase proteins, CRP is the major acute phase protein in rabbits, SAA and serum amyloid-P (SAP), which has remarkable structural similarity to CRP, are important in the mouse, and alpha1-acid glycoprotein and alpha2-macroglobulin are predominant in the rat. As immunoassay techniques and instrumentation improve, the measurement of acute phase proteins in blood or local tissue may well serve as the most sensitive and quantitative indicator of inflammation, and become routinely used for this purpose.
Extrahepatic Synthesis of Acute Phase Proteins
Andrzej Mackiewicz, Irving Kushner, Heinz Baumann in Acute Phase Proteins, 2020
Cells in higher animals can only survive and function properly in an environment of appropriate composition (“la fixité du milieu intérieur est la condition de la vie libre”).1 Various regulatory mechanisms ensure that the composition of this environment is kept relatively constant. The achieved state of equilibrium has been called homeostasis.2,3 Proteins are essential components of the fluids filling the extracellular environment. The ultimate function of the acute phase proteins and the purpose of the acute phase response is the maintenance of extracellular homeostasis. The site for this function is extravascular, i.e., in the immediate vicinity of cells or at the barrier structures delineating body compartments.
TIMP-1 Mediates Inflammatory and Immune Response to IL-6 in Adult Orbital Xanthogranulomatous Disease
Published in Ocular Immunology and Inflammation, 2020
Xia Ding, Yuan Cao, Yue Xing, Shengfang Ge, Ming Lin, Jin Li
The above mentioned results showed that TIMP-1 was upregulated in AOXGD tissues, and previous investigations revealed that TIMP-1 is upregulated in a coordinated early response to IL-6 stimulation.19,20 Furthermore, IL-6, the most important mediator of acute-phase protein synthesis, is required for modulating the dynamics of innate immune cell recruitment during acute inflammation.16,20,21 Thus, we examined the expression of the classical proinflammatory factor IL-6 by immunohistochemistry, and the results showed that the expression of IL-6 was higher in AOXGD tissues than in normal eyelid tissues (Figure 4). These data implied that the increased expression of IL-6 could induce increased secretion of TIMP-1 from M1 macrophages and thereby contribute to the development of AOXGD.
What moderates salivary markers of inflammation reactivity to stress? A descriptive report and meta-regression
Published in Stress, 2021
Danica C. Slavish, Yvette Z. Szabo
Inflammation is a broad physiological process that protects against infection and injury, and is an important correlate of stress and health (Ahmed, 2011). Inflammation can be measured by assessing levels of circulating inflammatory biomarkers, such as cytokines or acute phase proteins (Del Giudice & Gangestad, 2018). A growing literature has examined these markers of inflammation in saliva, as its ease of collection offers methodological advantages over more invasive measures like blood. Many salivary markers of inflammation increase in response to acute stress, but there is considerable variability in responses (Szabo et al., 2020; Slavish et al., 2015). Understanding methodological and demographic factors that influence their reactivity to stress may reveal which study designs are most effective for eliciting salivary immune responses to stress, as well as what individuals are most susceptible to stress-related increases in these markers.
Acute hazard assessment of silver nanoparticles following intratracheal instillation, oral and intravenous injection exposures
Published in Nanotoxicology, 2021
Ali Kermanizadeh, Nicklas R. Jacobsen, Agnieszka Mroczko, David Brown, Vicki Stone
Acute-phase proteins are a range of blood proteins predominately produced in the liver (Jain, Gautam, and Naseem 2011). The acute-phase response is a vital component of the innate immune system, which can be triggered by different stress stimuli including but not limited to infection, inflammation and physical trauma. To date, over 200 acute-phase proteins have been identified (Eklund, Niemi, and Kovanen 2012). The biological activities of these proteins are extremely important and varied and described previously in detail (Gruys et al. 2005). Serum amyloid A is a highly conserved protein produced by the liver. The plasma SAA concentration begins to increase 3–6 hr after an inflammatory stimulus, peaks on day 3, and returns to baseline levels after day 4 (this states that the peak of this response was not detected in this study). During an acute inflammatory response, the liver dictates a significant proportion of its synthesis capacity into producing SAA, which in mice comprised 2% of the total hepatic protein production (Eklund, Niemi, and Kovanen 2012). Important to this study is recognition that SAA is extremely immunologically active and plays a vital role in the recruitment of macrophages and neutrophils (Saber et al. 2014). In our experiments, the exposure to Ag NPs resulted in a dose-dependent increase in SAA3 levels most notable for the IV route of exposure but also following IT at lower levels. There was no evidence of a response following oral exposure at the specific doses and time-point. Similar observations have been observed following acute IV exposure to a different Ag NPs (Kermanizadeh et al. 2017) and IT exposure of multi-walled carbon nanotubes (Poulsen, Saber, Mortensen, et al. 2015).
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