Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemotactic cytokines (chemokines) play an important role in the recruitment of lymphocytes to tissue by regulating cellular adhesion and transendothelial migration. This study examined the expression and function of CXC (human monokine induced by gamma-interferon [HuMig], interleukin-8 [IL-8], and interferon-inducible protein-10 [IP-10]) and CC (macrophage inflammatory protein-1alpha [MIP-1alpha], MIP-1beta, regulated upon activation normal T lymphocyte expressed and secreted (RANTES), and macrophage chemoattractant protein-1 [MCP-1]) chemokines and their respective receptors on lymphocytes infiltrating human liver tumors. Chemokine and chemokine receptor expression was assessed by immunohistochemistry, flow cytometry, in situ hybridization and ribonuclease (RNAse) protection assays and function by in vitro chemotaxis of tumor-derived lymphocytes to purified chemokines and to HepG2 tumor cell culture supernatants. Tumor-derived lymphocytes showed strong chemotactic responses to both CC and CXC chemokines in vitro and expressed high levels of CXCR3 (HuMig and IP-10 receptor) and CCR5 (RANTES, MIP-1alpha, and MIP-1beta receptor). Expansion of tumor-derived lymphocytes in recombinant IL-2 increased expression of CXCR3. The corresponding chemokines were detected on vascular endothelium (HuMig, IL-8, MIP-1alpha, and MIP-1beta) and sinusoidal endothelium (HuMig, MIP-1alpha, MIP-1beta) in hepatocellular carcinoma. In vitro, HepG2 cells secreted functional chemotactic factors for tumor-derived lymphocytes that could be inhibited using anti-CCR5 or anti-CXCR3 monoclonal antibodies (MoAbs). Thus, lymphocytes infiltrating human liver tumors express receptors for and respond to both CXC and CC chemokines. The relevant chemokine ligands are expressed in hepatocellular carcinoma (HCC), particularly HuMig, which was strongly expressed by tumor endothelium, suggesting that they play a role in lymphocyte recruitment to these tumors in vivo. The ability of HepG2 cells to secrete lymphocyte chemotactic factors in vitro suggests that the tumor contributes to lymphocyte recruitment in vivo.
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PMID:Expression and function of CXC and CC chemokines in human malignant liver tumors: a role for human monokine induced by gamma-interferon in lymphocyte recruitment to hepatocellular carcinoma. 1038 45

Infiltration of renal allografts by leukocytes is a hallmark of acute transplant rejection. Chemokines attract leukocytes bearing specific chemokine receptors, and the specific leukocyte chemokine receptor phenotype is associated with types of immune responses, ie, T helper subtype 1 (Th1; CXC chemokine receptor 3 [CXCR3], CC chemokine receptor 5 [CCR5]) versus Th2 (CCR3, CCR4, CCR8). We studied the expression of the chemokine monocyte chemoattractant protein-1 and the chemokine receptors CCR2B and CXCR4 messenger RNA (mRNA) by in situ hybridization, as well as the chemokine receptors Duffy antigen receptor for chemokines (DARC) and CCR5 protein by immunohistochemistry in renal biopsy specimens with acute cellular rejection (n = 12) and acute vascular rejection (n = 8), transplant nephrectomy specimens (n = 6), and normal areas of tumor nephrectomy specimens (n = 5). CC chemokines and CC chemokine receptor mRNA expression were evaluated by ribonuclease protection assay in specimens from four transplant nephrectomies and one tumor nephrectomy. Upregulation of mRNAs for the chemokines, interferon-inducible protein-10 (IP-10); regulated on activation normal T-cell expressed and secreted; macrophage inflammatory protein-1alpha (MIP-1alpha); MIP-1beta; and lymphotactin, as well as the chemokine receptors, CCR2 and CCR5, were documented during allograft rejection. CCR1 mRNA was detectable in both allografts and controls, but CCR3 and CCR8 were absent. The number of CXCR4, CCR5, and CCR2B mRNAs expressing leukocytes and DARC-positive vessels increased during rejection episodes. CXCR4 mRNA was the most widely expressed. Leukocytes in diffuse interstitial infiltrates were mainly CCR5 positive, but in areas in which leukocytes formed nodular aggregates of infiltrating cells, the number of CCR5-positive cells was low. Instead, leukocytes in these nodular aggregates mainly expressed CXCR4. DARC was expressed on peritubular capillaries, where it was upregulated in areas of interstitial infiltration. Induction of chemokines during renal allograft rejection is accompanied by infiltration of leukocytes bearing the respective chemokine receptors. The upregulation of the CXCR3 ligand IP-10, as well as CCR5 and its ligands, in the absence of CCR3 and CCR8 is indicative that renal allograft rejection is primarily the result of a Th1-type immune response.
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PMID:Expression of chemokines and chemokine receptors during human renal transplant rejection. 1122 76

Lupus nephritis is characterized by immune complex deposition and inflammatory cell infiltration. Therefore, the initiation and progression of lupus nephritis in MRL/MpJ Fas(lpr/lpr) (MRL/lpr) mice were investigated, with a focus on the expression of several chemokines and chemokine receptors. Mice were monitored for proteinuria from 6 to 20 wk of age, and kidneys were examined every 2 wk by light microscopy, electron microscopy, and immunohistologic analyses. Furthermore, the expression of chemokines, chemokine receptors, and proinflammatory cytokines was analyzed in ribonuclease protection assays. MRL/lpr mice demonstrated increased expression of monocyte chemoattractant protein-1, regulated upon activation, normal T cell-expressed and -secreted protein, inducible protein of 10 kD, and macrophage inflammatory protein-1beta at week 8. At that time point, levels of circulating and glomerular immune complexes were increased, and no proteinuria or histopathologic signs of renal damage could be observed. As assessed in immunohistochemical and in situ hybridization analyses, monocyte chemoattractant protein-1 and regulated upon activation, normal T cell-expressed and -secreted protein expression was preferentially located in the glomeruli and interstitium. Mononuclear cell infiltration of the kidney was observed by weeks 10 to 12. At week 12, the renal expression of chemokine receptor 1 (CCR1), CCR2, and CCR5 was increased, mice became proteinuric, and renal damage was histologically evident. Finally, the expression of proinflammatory cytokines was detected (weeks 12 to 14). In summary, (1) chemokines are upregulated before inflammatory cell infiltration, proteinuria, and kidney damage are observed; (2) chemokine generation is restricted to sites of subsequent inflammatory cell infiltration, i.e., glomeruli and interstitium; (3) chemokine receptor expression parallels mononuclear cell infiltration; and (4) proinflammatory cytokines are upregulated later, in parallel with inflammatory cell infiltration and the onset of proteinuria. These results support the hypothesis that chemokines initiate leukocyte infiltration and precede proteinuria and renal damage in MRL/lpr mice.
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PMID:Chemokine expression precedes inflammatory cell infiltration and chemokine receptor and cytokine expression during the initiation of murine lupus nephritis. 1142 66