Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 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

Neutrophils (polymorphonuclear leukocytes; PMN) are phagocytic cells instrumental in the clearance of infectious pathogens. Human PMN are commonly thought to respond primarily to chemokines from the CXC family. However, recent findings suggest that under specific cytokine activation conditions, PMN can also respond to some CC chemokines. In this study, the effect of GM-CSF, a well-characterized PMN priming and maturation factor, on CC-chemokine receptor (CCR) expression in PMN was investigated. Constitutive expression of CCR1 and CCR3 mRNA in PMN was detected by ribonuclease protection assay. Following incubation of PMN with GM-CSF (0.01-10 ng/ml; 6 h) CCR1 mRNA expression was rapidly (approximately 1 h) up-regulated. In contrast, no significant induction of CCR2, CCR3, CCR4, or CCR5 mRNA was observed. CCR1 protein was also up-regulated by GM-CSF stimulation. GM-CSF-induced up-regulation of CCR1 showed functional consequences because GM-CSF-treated PMN, but not control cells, responded to the CC chemokines macrophage inflammatory protein-1alpha, monocyte chemoattractant protein-3, and RANTES in assays of chemotactic migration and intracellular calcium mobilization. These results suggest that PMN activated by the proinflammatory cytokine GM-CSF can change their receptor expression pattern and become responsive to CC chemokines.
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PMID:Granulocyte-macrophage colony stimulating factor up-regulates CCR1 in human neutrophils. 1114 99

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

Chemokines are small chemoattractant cytokines which participate in the migration of immune cells into the CNS and contribute to the T cell-mediated pathogenesis of multiple sclerosis (MS). The expression of chemokines and their receptors in freshly isolated mononuclear cells from peripheral blood (PBMC) was studied in relation to MS subtype, disease duration and progression in a total of 57 patients with MS (22 relapsing remitting, RRMS; 21 secondary progressive, SPMS; 14 primary progressive, PPMS) and 17 healthy controls. The RNA expression of CCR5 in PBMC was analysed by reverse transcription polymerase chain reaction (RT-PCR) using specific oligonucleotide primers. The PBMC levels of CCR5-ligands MIP-1 alpha/beta and RANTES, and chemokines MCP-1, IL-8, lymphotactin, IP-10 and I-309 were analysed by ribonuclease protection assay (RPA). Significantly increased intracellular CCR5 RNA expression intensity was detected in PPMS when compared with SPMS ( p=0.009), RRMS ( p=0.013), and controls ( p=0.023). However, the surface expression of CCR5 on CD4(+) cells from PBMC, analysed by flow cytometry, appeared to be similar in all MS subtypes and controls. The CCR5-ligands RANTES and MIP-1b were expressed constitutively in all patients and controls. Interleukin-8 was found in all MS subtypes and controls, but IP-10 was detected only in RRMS and SPMS, and lymphotactin occasionally in other subtypes but PPMS. MCP-1, MIP-1a or I-309 were not expressed in any of the groups studied. A correlation was found between the RNA levels of RANTES and CCR5 in PPMS ( r=0.735). Differential profile in the expression of CCR5 and chemokines between PPMS and other MS subtypes may contribute to differences in the pathogenesis of MS and thus can be of importance in the development of new treatments for MS.
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PMID:Differential intracellular expression of CCR5 and chemokines in multiple sclerosis subtypes. 1202 48

The majority of HIV-1-infected neonates and infants have a higher level of viremia and develop AIDS more rapidly than infected adults, including differences seen in clinical manifestations. To determine the mechanisms of HIV-1 infection in neonates vs. adults, we compared the replication kinetics of HIV-1 in neonatal (cord) and adult blood T lymphocytes and monocyte-derived macrophages (MDM) from seven different donors. We found that HIV-1 replicated 3-fold better in cord blood T lymphocytes compared with adult blood T lymphocytes and 9-fold better in cord MDM than adult MDM. We also show that this differential HIV-1 replication did not depend on differences in cell proliferative capabilities, cell surface expression of CD4, CXCR4, and CCR5, or in the amount of PCR products of reverse transcription, DNA synthesis, and translocation of preintegration complex into the nucleus in cord and adult T lymphocytes and MDM. Furthermore, using a single-cycle replication competent HIV-1-NL4-3-Env(-) luciferase amphotropic virus, which measures HIV-1 transcriptional activity independent of receptor and coreceptor expression, we found there was a 3-fold increase of HIV-1 LTR-driven luciferase expression in cord T lymphocytes compared with adult T lymphocytes and 10-fold in cord MDM than in adult MDM. The HIV-1 LTR-driven luciferase expression correlated with HIV-1 LTR transcription, as measured by ribonuclease protection assay. These data suggest that the increased replication of HIV-1 in cord blood compared with adult blood mononuclear cells is regulated at the level of HIV-1 gene expression, resulting in a higher level of viremia and faster disease progression in neonates than adults.
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PMID:Differential HIV-1 replication in neonatal and adult blood mononuclear cells is influenced at the level of HIV-1 gene expression. 1686 88

Synthetic siRNA has been considered as a highly promising therapeutic agent for human diseases. However, clinical use of siRNA has been hampered by instability in the body and inability to deliver sufficient RNA interference compounds to the tissues or cells. To address this challenge, we present here a single siRNA nanocapsule delivery technology, which is achieved by encapsulating a single siRNA molecule within a degradable polymer nanocapsule with a diameter around 20 nm and positive surface charge. As proof-of-concept, since CCR5 is considered a major silencing target of HIV therapy, CCR5-siRNA nanocapsules were delivered into 293T cells and successfully downregulated the CCR5 RNA fused with mCherry reporter RNA. In the absence of human serum, nanocapsules and lipofectamine silenced expression of CCR5-mCherry expression to 8% and 15%, respectively. Such nanocapsules maintain the integrity of siRNA inside even after incubation with ribonuclease and serum for 1 h; under the same conditions, siRNA is degraded in the native form or when formulated with lipofectamine. In the presence of serum, CCR5-siRNA nanocapsules knocked down CCR5-mCherry expression to less than 15% while siRNAs delivered through lipofectamine slightly knocked down the expression to 55%. In summary, this work provides a novel platform for siRNA delivery that can be developed for therapeutic purposes.
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PMID:Single siRNA nanocapsules for enhanced RNAi delivery. 2286 78