Molecular Pathology
Burkhard Madea in Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
Astrocytes are more resistant to hypoxic conditions than neurones. The S100 proteins have an A and B subunit and are small acidic calcium-binding proteins. S100B is highly specific for astrocytes, oligodendrocytes and ependymocytes in the central nervous system. Clinically, S100B seems to act as a serum marker of brain damage from cerebral injury and hypoxia/ischaemia. Li et al. [20] found that, in cases of asphyxiation due to neck compression, the number of astrocytes immunostained with anti-S100 or anti-GFAP was significantly decreased, compared with that for other asphyxiation and acute myocardial infarction. Reciprocally, serum S100B levels were significantly higher in asphyxiation by neck compression than in other types of asphyxiation. These observations imply that astrocytes and serum S100B would be available biomarkers for supporting the diagnosis of asphyxiation due to neck compression.
S-100 Protein
Masahiko Mori in Histochemistry of the Salivary Glands, 2019
The S-100 protein isolated from brain belongs to a group of Ca binding proteins which include calmodulin, troponin C, and intestinal calcium binding protein. S-100 protein is composed of two subunits, α and β, which can be distinguished by specific monoclonal antibodies. Immunohistochemical studies of the distribution of S-100 protein using polyclonal anti-S-100 protein antiserum have reported positive reactions in central and peripheral nerve structures,1-6 melanoma cells,6–8 Langerhans’ cells of epidermis and tumors,9,10 chondrocytes,11,12 and myoepithelially derived cells of salivary13–27 and mammary glands,28,29 and skin adenaxia.30 Modified myoepithelial cells of pleomorphic adenomas usually stain for S-100 protein. Histochemical studies using monoclonal antibodies to S-100 protein or S-100 a and β subunits have been described by Loeffel et al.31 and Vanstapel et al.32
Neuropathology Of Neuro-Ophthalmic Disorders
Vivek Lal in A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Schwannoma is a slow-growing, benign nerve sheath tumor accounting for less than 1% of the orbital tumors and arises from branches of nerves traversing the orbit such as oculomotor, trochlear or abducens.36–38 Due to complexity of orbital structures, it's difficult to point out the origin. Small tumors are asymptomatic, but as they grow they compress the nerve in which they arise and also the surrounding structures. Most of the patients are adult and proptosis is the commonest presentation. Lid swelling is another prominent feature. MRI is very sensitive neuro-imaging technique for diagnosis. Macroscopically, a schwannoma appears encapsulated mass with a homogeneous, grayish-white cut surface, which may contain areas of hemorrhage. Histologically, schwannoma shows hypo- and hypercellular areas (Figure 25.18a). The cells show nuclear palisading and Verocay body formation (Figure 25.18b). The individual cells show spindle-shaped nuclei with pointed ends. These cells express S-100 protein on immunostaining. Mitosis and necrosis are rarely found. Hyalinized blood vessels as well as secondary degenerative changes such as edema, variable cystic degeneration, and infiltration by foamy macrophages are common findings. Orbital schwannomas often extend into cavernous sinus. A complete surgical excision is usually curative.
MiR-30a Regulates S100A12-induced Retinal Microglial Activation and Inflammation by Targeting NLRP3
Published in Current Eye Research, 2019
S100/calgranulin family comprises the largest group of calcium-binding proteins.7 All of the S100 proteins are characterized by the presence of two calcium-binding EF-hand motifs with different affinities for calcium.7 In the S100/calgranulin family, S100A8, S100A9, and S100A12 have been proved to play a pivotal role in exacerbating inflammatory response cooperating with inflammatory factors. S100A12 has been demonstrated to act independently from S100A8/S100A9, which is additionally known as EN-RAGE (extracellular newly identified receptor for AGE-binding protein).7,8 S100A12 is released from activated neutrophils and macrophages, which has proinflammatory effects on immune cells, and promotes inflammatory response.7–9 Our previous study has shown that plasma levels of S100A12 are closely associated with presence and severity of DR.9 However, to the best of our knowledge, whether S100A12 can contribute to the inflammatory changes of DR and microglial activation have not been fully elucidated.
A review on proteomics analysis to reveal biological pathways and predictive proteins in sulfur mustard exposed patients: roles of inflammation and oxidative stress
Published in Inhalation Toxicology, 2019
Hojat Borna, Seyed Hojjat Hosseini Qale Noe, Asghar Beigi Harchegani, Nima Rahmani Talatappe, Mahdi Ghatrehsamani, Mostafa Ghanei, Alireza Shahriary
S100 proteins are a family of calcium-binding proteins which are increased in SM-exposed patients. These proteins, especially S100-A8, S100-A9 and S100-A12, are predominantly expressed in phagocytes and are strongly associated with pro-inflammatory responses (Sedaghat & Notopoulos, 2008). They are secreted particularly at sites of inflammation. Increased content of these S100 proteins correlated with inflammatory diseases activity (Sedaghat & Notopoulos, 2008). Previous studies identified high levels of these proteins in several inflammatory disorders such as rheumatoid arthritis, chronic bronchitis and cystic fibrosis (Foell et al., 2004). Therefore, increased levels of these proteins in SM-exposed individuals suggest the existence of ongoing tissue damage along with severe inflammatory reactions.
Immunological mechanisms underlying sterile inflammation in the pathogenesis of atherosclerosis: potential sites for intervention
Published in Expert Review of Clinical Immunology, 2021
Roland Truong, Finosh G. Thankam, Devendra K. Agrawal
S100 proteins have similar characteristics to that of HMGB1. S100 proteins act as DAMPs that interact with TLR2, TLR3, TLR4, and RAGE following their release from phagocytes and modulate cellular pro-inflammatory response via NF-κB pathway [100]. S100 proteins have a wide range of intra- and extracellular functions to regulate cell growth and death. It belongs to a calcium-binding cytosolic protein family comprising the subtypes S100A8, S100A9, and S100A12 which mediate vascular inflammation and atherosclerosis [101] where S100A12 is the most predictive of coronary heart disease in a prospective population-based cohort study [102]. However, the increased S100A8/A9 levels are the predicting factors for the future myocardial infarction, stroke, and cardiovascular death [103]. ApoE−/- S100A9−/- double knockout mice demonstrated reduction in aortic atherosclerosis [104]. Though neutrophils are relatively lower in number than monocytes/macrophages in atherosclerotic lesions, there is a larger abundance of S100A8/A9 in neutrophils than monocytes/macrophages.
Related Knowledge Centers
- Aryl Hydrocarbon Receptor
- Calcium
- Calmodulin
- Neural Crest
- Protein
- Schwann Cell
- Chondrocyte
- Melanocyte
- Basic Helix–Loop–Helix
- Gene