Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P05109 (S100A8)
 1,212 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

So far, microglial activation in cerebral ischemia has only been studied in different animal models. We have investigated the activation of microglial cells in human cerebral ischemia. As a marker for the activation of these "brain macrophages," we have used the macrophage inhibitor factor-related-proteins MRP-8 and MRP-14, which belong to the calcium binding S-100 protein family. The proteins can be detected on microglial cells in bacterial encephalitis and Alzheimer's disease but have so far not been studied in non-inflammatory diseases, in which microglial activation also occurs. Antibodies against MRP-8 and -14 detected ramified microglial cells within the first 3 days after cerebral infarction. Labeled cells were found selectively in the periinfarctional area. To support the notion that these cells belong to the locally activated resident microglial population, we studied their proliferation rate by staining the Ki-67 antigen with the antibody MIB-1. Double-labeling clearly showed that in the early phase of cerebral infarction microglial cells in the periinfarctional area express MRP-8 and -14 and also proliferate. Surprisingly, MRPs are expressed no longer than 3 days post infarction. This indicates that the activation of the resident microglia is an early step of tissue reaction after cerebral infarction. Additionally, we found evidence that microglial cells contribute to the population of phagocytes only during the first 3 days post infarction. The majority of lipid phagocytes found in the later stages are obviously recruited from the blood-borne macrophage pool.
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PMID:Expression of the S-100 proteins MRP-8 and -14 in ischemic brain lesions. 898 65

S100 protein A8 and A9 naturally form a stable heterocomplex. Recently, we have proved that S100A9 overexpression in various adenocarcinomas is associated with poor tumor differentiation. In this study, we examined the relationship between the expression of each protein and the pathological parameters that reflect the aggressiveness of carcinoma, in invasive ductal carcinoma (IDC) of the breast. Serial paraffin-embedded tissue sections from 101 IDC cases were immunostained with respective monoclonal antibodies, and the results were as follows: 1) A positive correlation of immunoreactivity between S100A8 and S100A9 was noticed (r=0.873 and P<0.0001); 2) The percentage of S100A9-positive tumor cells was higher than that of S100A8-positive tumor cells (P<0.001), and S100A8 alone was not detected in any case; 3) Overlap between S100A8 and S100A9 staining patterns was found in the corresponding tissue areas, but S100A9 positivity was also observed in S100A8-negative tumor cells; 4) The immunopositivity for each protein also correlated with the mitotic activity, MIB-1 index, HER2 overexpression, node metastasis, and poor pT categories and pStage (P<0.05); 5) Co-expression of both proteins was associated with poor tumor differentiation, vessel invasion, node metastasis, and poor pStage (P<0.05). Furthermore, co-expression of the proteins was also observed in MCF-7 cells, and it was suggested that the immunolocalization is related with cell cycle. Our conclusions are as follows: 1) It is suggested that S100A8 is S100A9-dependently expressed and acquires the protein stability by S100A8/A9 heterocomplex formation; 2) S100A8 and S100A9 overexpression should be considered marker of poor prognosis in IDC.
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PMID:S100A8 and S100A9 overexpression is associated with poor pathological parameters in invasive ductal carcinoma of the breast. 1853 48