Home About us Contact
|
Home About us Contact | ||
|
|
||
Possible Therapeutic Target (possible + therapeutic_target)
Selected AbstractsBlockade of chloride intracellular ion channel 1 stimulates A, phagocytosisJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2008Silvia Paradisi Abstract In amyloid-, (A,)-stimulated microglial cells, blockade of chloride intracellular ion channel 1 (CLIC1) reverts the increase in tumor necrosis factor-, and nitric oxide (NO) production and results in neuroprotection of cocultured neurons. This effect could be of therapeutic efficacy in Alzheimer's disease (AD), where microglial activation may contribute to neurodegeneration, but it could reduce A, phagocytosis, which could facilitate amyloid plaque removal. Here, we analyzed the CLIC1 blockade effect on A,-stimulated mononuclear phagocytosis. In the microglial cell line BV-2, A,25,35 treatment enhanced fluorescent bead phagocytosis, which persisted also in the presence of IAA-94, a CLIC1 channel blocker. The same result was obtained in rat primary microglia and in BV2 cells, where CLIC1 expression had been knocked down with a plasmid producing small interfering RNAs. To address specifically the issue of A, phagocytosis, we treated BV-2 cells with biotinylated A,1,42 and measured intracellular amyloid by morphometric analysis. IAA-94-treated cells showed an increased A, phagocytosis after 24 hr and efficient degradation of ingested material after 72 hr. In addition, we tested A,1,42 phagocytosis in adult rat peritoneal macrophages. Also, these cells actively phagocytosed A,1,42 in the presence of IAA-94. However, the increased expression of inducible NO synthase (iNOS), stimulated by A,, was reverted by IAA-94. In parallel, a decrease in NO release was detected. These results suggest that blockade of CLIC1 stimulates A, phagocytosis in mononuclear phagocytes while inhibiting the induction of iNOS and further point to CLIC1 as a possible therapeutic target in AD. © 2008 Wiley-Liss, Inc. [source] Expression of KiSS-1 Gene and its Role in Invasion and Metastasis of Human Hepatocellular CarcinomaTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2009Zang Shengbing Abstract KiSS-1 has been identified as a putative metastasis-suppressor gene in human melanomas and breast cancer cell lines. Although loss of KiSS-1 expression has been associated with progression and poor prognosis of various cancers, the exact role of KiSS-1 expression in HCC is not well-defined. Our study investigated KiSS-1 expression levels in HCC and its role in invasion and metastasis of human HCC. The expression levels of KiSS-1 and MMP-9 protein were determined by tissue microarray (TMA) serial sections, immunohistochemistry and semi-quantitative image analysis. All clinical and histological data obtained were subjected to statistical analysis. The expression of KiSS-1 protein in HCC and intrahepatic metastasis lesions was significantly lower (P < 0.01) when compared with non-tumor liver tissue and normal liver tissue. Multivariate analysis revealed a significant inverse correlation between KiSS-1 expression and ,1 TNM stage, (F = 7.113, P < 0.01) and ,2intrahepatic metastasis (t = 2.898, P < 0.01). Loss of KiSS-1 in intrahepatic metastasis versus primary carcinomas was statistically significant (P<0.01). We also found a negative correlation between KiSS-1 and MMP-9 expression in HCC (r = -0.506, P < 0.01). We conclude that loss of KiSS-1 during HCC metastasis, along with a concomitant upregulation of MMP-9 suggests a possible mechanism for cell motility and invasion during HCC metastasis, with KiSS-1 emerging as a possible therapeutic target during HCC metastasis. Anat Rec, 292:1128,1134, 2009. © 2009 Wiley-Liss, Inc. [source] Autocrine/paracrine involvement of insulin-like growth factor-I and its receptor in chronic lymphocytic leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2005Roxana Schillaci Summary Chronic lymphocytic leukaemia (CLL) is characterized by the accumulation of long-lived B lymphocytes blocked in G0/1 by impaired apoptosis. As insulin-like growth factor-I (IGF-I) is known for its antiapoptotic effects in different cell types, we investigated whether IGF-I and its receptor (IGF-IR) participate in autocrine/paracrine loops affecting the survival of CLL cells. IGF-IR protein and mRNA was present in CLL cells in 44% and 59% of patients respectively. IGF-IR expression in CLL patients was positively correlated with the expression of the antiapoptotic protein Bcl-2 and was involved in CLL cell survival in vitro. Serum IGF-I was elevated in CLL patients, but growth hormone (GH) was normal. CLL cells expressed IGF-I mRNA and secreted the growth factor in vitro. Therefore, local production of IGF-I can account for the increased levels of serum IGF-I, independently of GH, and may be related to autocrine/paracrine control of lymphocyte survival acting at IGF-IR. This is the first demonstration of IGF-IR expression in a subgroup of CLL patients and of its antiapoptotic effects in vitro, highlighting the importance of this growth factor receptor as a possible therapeutic target in CLL. [source] Snake venom hyaluronidase: a therapeutic targetCELL BIOCHEMISTRY AND FUNCTION, Issue 1 2006K. Kemparaju Abstract The diffusion of toxins from the site of a bite into the circulation is essential for successful envenomation. Degradation of hyaluronic acid in the extracellular matrix (ECM) by venom hyaluronidase is a key factor in this diffusion. Hyaluronidase not only increases the potency of other toxins but also damages the local tissue. In spite of its important role, little attention has been paid to this enzyme. Hyaluronidase exists in various isoforms and generates a wide range of hyaluronic acid degradation products. This suggests that beyond its role as a spreading factor venom hyaluronidase deserves to be explored as a possible therapeutic target for inhibiting the systemic distribution of venom and also for minimizing local tissue destruction at the site of the bite. Copyright © 2005 John Wiley & Sons, Ltd. [source] 2231: Age-related modifications in RPE cellsACTA OPHTHALMOLOGICA, Issue 2010E MANNERMAA Age-related macular degeneration (AMD) is a multi-factorial polygenetic aging disease. It has been shown that RPE dysfunction predisposes neural retinal dysfunction and the development of choroidal neovascularization. The pathogenesis of age-related macular degeneration (AMD) essentially involves chronic oxidative stress, increased accumulation of lipofuscin in retinal pigment epithelial (RPE) cells and extracellular drusen formation, as well as the presence of chronic inflammation. The capacity to prevent the accumulation of cellular cytotoxic protein aggregates is decreased in senescent cells which may evoke lipofuscin accumulation into lysosomes in postmitotic RPE cells. This presence of lipofuscin decreases lysosomal enzyme activity and impairs autophagic clearance of damaged proteins which should be removed from cells. Proteasomes are another crucial proteolytic machine which degrades especially cellular proteins damaged by oxidative stress. The cross-talk between lysosomes, autophagy and proteasomes in RPE cell protein aggregation, their role as a possible therapeutic target and their involvement in the pathogenesis of AMD is discussed. In addition, age related changes in Bruch's membrane and choroidal blood flow may take part in the pathogenesis of AMD. This will be also discussed. [source] Pharmacological characterization of the rat brain P2Y1 receptor expressed in HEK293 cells: Ca2+ signaling and receptor regulationDRUG DEVELOPMENT RESEARCH, Issue 2-3 2001Christian Vöhringer Abstract The increasing number of ATP- and UTP-sensitive membrane receptors identified by cloning represent either ligand-activated ion channels (P2X) or G-protein-coupled receptors (P2Y). Adenosine, ATP, and UTP have potential application in the management of pain, cancer, and some cardiovascular and pulmonary diseases and are also involved in inflammatory processes in the brain. Therefore, P2Y receptors seem to be promising therapeutic targets. Multiple P2Y receptor subtypes, classified pharmacologically, are mainly linked to activation of phospholipase C (PLC). The present study further characterizes the rat brain P2Y1 wild-type receptor (rP2Y1 -wt) and the eGFP-tagged receptor (rP2Y1 -eGFP) stably expressed in HEK293 cells, thus shedding light on receptor regulation. Both receptors were analyzed by measuring Ca2+ responses in single cells. The rP2Y1 -eGFP receptor was coupled to Ca2+ release like the rP2Y1 -wt receptor. Experiments using the PLC inhibitor U73122 confirm the functional activation of PLC, through rP2Y1 -eGFP activation. The P2Y1 -selective agonists 2-MeSADP and 2-MeSATP were most potent at the heterologously expressed receptors. We found a ligand selectivity typical for P2Y1 receptors (2-MeSADP = 2-MeSATP > ADP > ATP,S, ATP >> UTP). Fluorescence microscopy and Ca2+ measurements confirm that the rP2Y1-eGFP receptor during homologous desensitization is subjected to processes leading to agonist-induced internalization. The kinetics of receptor resensitization were also examined. Therefore, rP2Y1 -eGFP expressing cells are suitable to determine the physiological P2Y1 receptor signaling pathway and can be a helpful tool to identify drugs acting at P2Y1 receptors as possible therapeutic targets. Drug Dev. Res. 53:172,179, 2001. © 2001 Wiley-Liss, Inc. [source] Tau oligomers and aggregation in Alzheimer's diseaseJOURNAL OF NEUROCHEMISTRY, Issue 6 2010Marco A. Meraz-Ríos J. Neurochem. (2010) 112, 1353,1367. Abstract We are analyzing the physiological function of Tau protein and its abnormal pathological behavior when this protein is self-assemble into pathological filaments. These aggregates of Tau protein are the main components in many diseases such as Alzheimer's disease (AD). Recent studies suggest that Tau acquires complex oligomeric conformations which may be toxic. In this review, we emphasized the possible phenomena implicated in the formation of these oligomers. Studies with chemical inductors indicates that the microtubule-binding domain is the most important region involved in Tau aggregation and showed the requirement of a pre-arrange Tau in abnormal conformation to promote self-assembly. Transgenic animal models and AD neuropathology studies showed that post-translational modifications are also implicated in Tau aggregation and neural cell death during AD development. Therefore, we analyzed some events that could be present during Tau aggregation. Finally, we included a brief discussion of the possible relation between glucose metabolism dysfunction in AD, and data of Tau aggregation by using aggregation inhibitors. In conclusion, the process Tau aggregation deserves further investigations to design possible therapeutic targets to inhibit the toxicity of these aggregates and it is possible that could be extended to other diseases with similar etiology. [source] Expansion of circulating T cells resembling follicular helper T cells is a fixed phenotype that identifies a subset of severe systemic lupus erythematosusARTHRITIS & RHEUMATISM, Issue 1 2010Nicholas Simpson Objective In the sanroque mouse model of lupus, pathologic germinal centers (GCs) arise due to increased numbers of follicular helper T (Tfh) cells, resulting in high-affinity anti,double-stranded DNA antibodies that cause end-organ inflammation, such as glomerulonephritis. The purpose of this study was to examine the hypothesis that this pathway could account for a subset of patients with systemic lupus erythematosus (SLE). Methods An expansion of Tfh cells is a causal, and therefore consistent, component of the sanroque mouse phenotype. We validated the enumeration of circulating T cells resembling Tfh cells as a biomarker of this expansion in sanroque mice, and we performed a comprehensive comparison of the surface phenotype of circulating and tonsillar Tfh cells in humans. This circulating biomarker was enumerated in SLE patients (n = 46), Sjögren's syndrome patients (n = 17), and healthy controls (n = 48) and was correlated with disease activity and end-organ involvement. Results In sanroque mice, circulating Tfh cells increased in proportion to their GC counterparts, making circulating Tfh cells a feasible human biomarker of this novel mechanism of breakdown in GC tolerance. In a subset of SLE patients (14 of 46), but in none of the controls, the levels of circulating Tfh cells (defined as circulating CXCR5+CD4+ cells with high expression of Tfh-associated molecules, such as inducible T cell costimulator or programmed death 1) were increased. This cellular phenotype did not vary with time, disease activity, or treatment, but it did correlate with the diversity and titers of autoantibodies and with the severity of end-organ involvement. Conclusion These findings in SLE patients are consistent with the autoimmune mechanism in sanroque mice and identify Tfh effector molecules as possible therapeutic targets in a recognizable subset of patients with SLE. [source] | |||||||||||||