Search results for " mitogen-activated protein kinase"
showing 10 items of 188 documents
Signaling pathways of the TREM-1- and TLR4-mediated neutrophil oxidative burst.
2008
The triggering receptor expressed on myeloid cells 1 (TREM-1) is involved in the innate inflammatory response to microbial infections. Activation and expression of TREM-1 by polymorphonuclear neutrophils (PMN) occurs in concert with Toll-like receptors (TLR) such as TLR4 for bacterial lipopolysaccharide. However, it is currently unclear how this is mediated on a molecular level. Using pharmacological inhibitors and Western blot analysis we demonstrate that phosphatidyl inositide 3-kinase, phospholipase C and the mitogen-activated kinase p38MAPK are essential for the TREM-1- and TLR4-induced oxidative burst of human PMN. The activation of protein kinase B and extracellular signal-related kin…
Molecular mechanism of α2β1 integrin interaction with human echovirus 1
2009
Conformational activation increases the affinity of integrins to their ligands. On ligand binding, further changes in integrin conformation elicit cellular signalling. Unlike any of the natural ligands of alpha2beta1 integrin, human echovirus 1 (EV1) seemed to bind more avidly a 'closed' than an activated 'open' form of the alpha2I domain. Furthermore, a mutation E336A in the alpha2 subunit, which inactivated alpha2beta1 as a collagen receptor, enhanced alpha2beta1 binding to EV1. Thus, EV1 seems to recognize an inactive integrin, and not even the virus binding could trigger the conformational activation of alpha2beta1. This was supported by the fact that the integrin clustering by EV1 did …
Design, synthesis, and biological evaluation of novel disubstituted dibenzosuberones as highly potent and selective inhibitors of p38 mitogen activat…
2012
Synthesis, biological testing, structure-activity relationships (SARs), and selectivity of novel disubstituted dibenzosuberone derivatives as p38 MAP kinase inhibitors are described. Hydrophilic moieties were introduced at the 7-, 8-, and 9-position of the 2-phenylamino-dibenzosuberones, improving physicochemical properties as well as potency. Extremely potent inhibitors were obtained, with half-maximal inhibitory concentration (IC(50)) values in the low nM range in a whole blood assay measuring the inhibition of cytokine release. The high potency of the target compounds together with the outstanding selectivity of this novel class of compounds toward p38 mitogen activated protein (MAP) kin…
Structure-Activity Relationships and X-ray Structures Describing the Selectivity of Aminopyrazole Inhibitors for c-Jun N-terminal Kinase 3 (JNK3) ove…
2009
c-Jun N-terminal kinase 3alpha1 (JNK3alpha1) is a mitogen-activated protein kinase family member expressed primarily in the brain that phosphorylates protein transcription factors, including c-Jun and activating transcription factor-2 (ATF-2) upon activation by a variety of stress-based stimuli. In this study, we set out to design JNK3-selective inhibitors that had >1000-fold selectivity over p38, another closely related mitogen-activated protein kinase family member. To do this we employed traditional medicinal chemistry principles coupled with structure-based drug design. Inhibitors from the aminopyrazole class, such as SR-3576, were found to be very potent JNK3 inhibitors (IC(50) = 7 nm)…
Inter- and intracellular signaling in amyotrophic lateral sclerosis: role of p38 mitogen-activated protein kinase.
2006
The pathogenetic processes underlying the selective motor neuron degeneration in amyotrophic lateral sclerosis (ALS) are complex and still not completely understood even in the cases of inherited disease caused by mutations in the Cu/Zn superoxide dismutase-dependent (SOD1) gene. Recent evidence supports the view that ALS is not a cell-autonomous disease and that glial-neuron cross-talk, throughout cytokines and other toxic factors like the nitric oxide and superoxide, is a crucial determinant for the induction of motor neuron death. This cell-cell interaction may determine the progression of the disease through processes that are likely independent of the initial trigger and that may conve…
Redox signaling in acute pancreatitis
2015
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On th…
L-selectin regulates human neutrophil transendothelial migration
2021
ABSTRACT The migration of circulating neutrophils towards damaged or infected tissue is absolutely critical to the inflammatory response. L-selectin is a cell adhesion molecule abundantly expressed on circulating neutrophils. For over two decades, neutrophil L-selectin has been assigned the exclusive role of supporting tethering and rolling – the initial stages of the multi-step adhesion cascade. Here, we provide direct evidence for L-selectin contributing to neutrophil transendothelial migration (TEM). We show that L-selectin co-clusters with PECAM-1 – a well-characterised cell adhesion molecule involved in regulating neutrophil TEM. This co-clustering behaviour occurs specifically during …
Phospho-p38 MAPK expression in COPD patients and asthmatics and in challenged bronchial epithelium
2015
<b><i>Background:</i></b> The role of mitogen-activated protein kinases (MAPK) in regulating the inflammatory response in the airways of patients with chronic obstructive pulmonary disease (COPD) and asthmatic patients is unclear. <b><i>Objectives:</i></b> To investigate the expression of activated MAPK in lungs of COPD patients and in bronchial biopsies of asthmatic patients and to study MAPK expression in bronchial epithelial cells in response to oxidative and inflammatory stimuli. <b><i>Methods:</i></b> Immunohistochemical expression of phospho (p)-p38 MAPK, p-JNK1 and p-ERK1/2 was measured in bronchial mucosa in pat…
Traditional Chinese herbal medicine at the forefront battle against COVID-19: Clinical experience and scientific basis.
2020
Abstract Background Throughout the 5000-year history of China, more than 300 epidemics were recorded. Traditional Chinese herbal medicine (TCM) has been used effectively to combat each of these epidemics’ infections, and saved many lives. To date, there are hundreds of herbal TCM formulae developed for the purpose of prevention and treatment during epidemic infections. When COVID-19 ravaged the Wuhan district in China in early January 2020, without a deep understanding about the nature of COVID-19, patients admitted to the TCM Hospital in Wuhan were immediately treated with TCM and reported later with >90% efficacy. Approach We conducted conduct a systematic survey of various TCM herbal pre…
Shikonin reduces oedema induced by phorbol ester by interfering with IκBα degradation thus inhibiting translocation of NF-κB to the nucleus
2010
Background and purpose In the present paper we studied the effect of shikonin on ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), and determined the mechanisms through which shikonin might exert its topical anti-inflammatory action. Experimental approach Acute ear oedema was induced in mice by topical application of TPA. The in vitro assays used macrophages RAW 264.7 cells stimulated with lipopolysaccharide. Cyclooxygenase-2, inducible nitric oxide synthase, protein kinase Calpha, extracellular signal-regulated protein kinase (ERK), phosphorylated ERK (pERK), c-Jun N-terminal kinase (JNK), pJNK, p38, p-p38, p65, p-p65, inhibitor protein of nuclear factor-kappaB (NF-kappaB) …