Our results suggest that TNF-alpha plays a critical role in the development of brain oedema in ALF, and that both vasogenic and cytotoxic mechanisms may be involved. Increased BBB permeability may be because of the disruption of TJs, and loss of the TJ-associated protein occludin.
A cDNA was isolated from interleukin 3-developed, mouse bone marrow-derived mast cells (MCs) that contained an insert (designated mRasGRP4) that had not been identified in any species at the gene, mRNA, or protein level. By using a homology-based cloning approach, the ϳ2.6-kb hRasGRP4 transcript was also isolated from the mononuclear progenitors residing in the peripheral blood of normal individuals. This transcript information was then used to locate the RasGRP4 gene in the mouse and human genomes, to deduce its exon/ intron organization, and then to identify 10 single nucleotide polymorphisms in the human gene that result in 5 amino acid differences. The >15-kb hRasGRP4 gene consists of 18 exons and resides on a region of chromosome 19q13.1 that had not been sequenced by the Human Genome Project. Human and mouse MCs and their progenitors selectively express RasGRP4, and this new intracellular protein contains all of the domains present in the RasGRP family of guanine nucleotide exchange factors even though it is <50% identical to its closest homolog. Recombinant RasGRP4 can activate H-Ras in a cation-dependent manner. Transfection experiments also suggest that RasGRP4 is a diacylglycerol/phorbol ester receptor. Transcript analysis of an asthma patient, a mastocytosis patient, and the HMC-1 cell line derived from a MC leukemia patient revealed the presence of substantial amounts of non-functional forms of hRas-GRP4 due to an inability to remove intron 5 in the precursor transcript. Because only abnormal forms of hRas-GRP4 were identified in the HMC-1 cell line, this immature MC progenitor was used to address the function of RasGRP4 in MCs. HMC-1 leukemia cells differentiated and underwent granule maturation when induced to express a normal form of RasGRP4. Thus, RasGRP4 plays an important role in the final stages of MC development.
In Arabidopsis thaliana, MAIGO 2 (MAG2) is involved in protein transport between the endoplasmic reticulum (ER) and the Golgi apparatus via its association with the ER-localized t-SNARE components SYP81/AtUfe1 and SEC20. To characterize the molecular machinery of MAG2-mediated protein transport, we explored MAG2-interacting proteins using transgenic A. thaliana plants expressing TAP-tagged MAG2. We identified three proteins, which were designated as MAG2-INTERACTING PROTEIN 1-3 [MIP1 (At2g32900), MIP2 (At5g24350) and MIP3 (At2g42700)]. Both MIP1 and MAG2 localized to the ER membrane. All of the mag2, mip1, mip2 and mip3 mutants exhibited a defect in storage protein maturation, and developed abnormal storage protein body (MAG body) structures in the ER of seed cells. These observations suggest that MIPs are closely associated with MAG2 and function in protein transport between the ER and Golgi apparatus. MIP1 and MIP2 contain a Zeste-White 10 (ZW10) domain and a Sec39 domain, respectively, but have low sequence identities (21% and 23%) with respective human orthologs. These results suggest that the plant MAG2-MIP1-MIP2 complex is a counterpart of the triple-subunit tethering complexes in yeast (Tip20p-Dsl1p-Sec39p) and humans (RINT1-ZW10-NAG). Surprisingly, the plant complex also contained a fourth member (MIP3) with a Sec1 domain. There have been no previous reports showing that a Sec1-containing protein is a subunit of ER-localized tethering complexes. Our results suggest that MAG2 and the three MIP proteins form a unique complex on the ER that is responsible for efficient transport of seed storage proteins.
Purpose: Previous poor results of liver transplantation (LT) have been confirmed in patients with advanced hepatocellular carcinoma (HCC). Adenovirus-mediated delivery of herpes simplex virus thymidine kinase (ADV-TK) therapy is an established adjuvant treatment in cancer, and we evaluated its potential as an adjuvant treatment for HCC patients who underwent LT.Experimental Design: Forty-five HCC patients with tumors >5 cm in diameter participated in the study over a follow-up period of 50 months. Among these patients, 22 received LTonly, and 23 received LTcombined with ADV-TK therapy. All HCC patients enrolled in this study had tumors >5 cm in diameter and no metastasis in lungs or bones was detected by computed tomography or magnetic resonance imaging scans. Results: The recurrence-free survival and the overall survival in the LT plus ADV-TK therapy group were 43.5% and 69.6%, respectively, at 3 years; both values were significantly higher than those in the LT-only group (9.1% and 19.9%, respectively). In the nonvascular invasion subgroup, overall survival was 100% and recurrence-free survival was 83.3% in the patients receiving LT plus ADV-TK, significantly higher than the patients receiving LTonly. Conclusions: HCC patients with no vascular invasion could be selected for LT followed by adjuvant ADV-TK therapy, regardless of intrahepatic huge or diffuse tumor. We propose that the current criteria for LT based on tumor size may be expanded if accompanied by ADV-TK therapy due to improved prognosis.Hepatocellular carcinoma (HCC) is currently the fifth most common neoplasm in the world (1, 2). The majority of HCC (80-90%) are associated with underlying liver diseases related to post-hepatitis cirrhosis, hemochromatosis, or alcohol abuse, and the incidence of HCC continues to increase steadily (3).The population of HCC patients in China is the largest around the world and f230, 000 people die of HCC yearly, counting 53% of the total number of the global death population (4). In the past 30 years, liver transplantation (LT) has become an important technique in HCC treatment because of the triple advantage of removing the tumor, preventing formation of metachronous lesions on underlying cirrhosis, and restoring normal liver function (5). However, high recurrence rates (32-54%) and poor outcomes (5-year survival rate of <40%) were recorded from the first series of transplanted patients. These poor results were mostly related to unrestrictive selection criteria and inclusion of patients with macroscopic vascular invasion, lymph node involvement, and extrahepatic spread (6, 7). The landmark study of Mazzaferro et al. (8) in 1996 established LT as a viable option to treat HCC, based on the poor outcome of advanced HCC patients receiving LT and the limited source of donor organs. Their criteria have come to be known as the Milan criteria (unifocal V5 cm in diameter or V3 foci V3 cm in diameter) and have been widely applied throughout the world in the selection of patients with small HCC for transplantation (9 ...
Previous studies have identified several HLA-B specificities that are associated with nasopharyngeal carcinoma (NPC) in populations of Chinese descent, in particular HLA-B35, -B38, -B46, and -B58. Perhaps except for HLA-B46, other associations cannot be simply accounted for by the linkage disequilibrium between HLA-A and B loci. The human major histocompatibility complex (MHC) class I chain-related gene A (MICA) maps 46 kb centromeric to HLA-B and is highly polymorphic; it encodes a stress-inducible protein which functions as a ligand for the NKG2D/DAP10 complex to activate natural killer (NK) cells, gammadelta T cells, and CD8(+) T cells. We postulated MICA gene as a susceptibility factor for nasopharyngeal carcinoma, an Epstein-Barr virus-associated malignancy. In this study, 218 unrelated patients newly diagnosed with NPC and 196 randomly selected healthy controls from southern China mainland were analyzed for the short tandem repeat polymorphism of exon 5 of MICA gene (MICA-STR) and MICA gene deletion, using fluorescent polymerase chain reaction-gene scanning (PCR/size-sequencing) and polymerase chain reaction-sequence-specific priming (PCR/SSP) technology. MICA*A9 was present at significantly increased frequency in the patient group (P (C)=0.0001002, OR=2.528, 95% CI=1.636-3.907), whereas the frequency of MICA*A5.1 was significantly decreased (P (C)=0.006, OR=0.594, 95% CI=0.437-0.806). Gender-based stratification revealed a significant increase of MICA*A9 frequency (P (C)=0.000072, OR=3.255, 95% CI=1.855-5.709) and a significant decrease of MICA*A5.1 frequency (P (C)=0.000737, OR=0.486, 95% CI=0.337-0.702) in male patients with NPC (N=166), compared with male normal controls (N=120). A significant interaction between MICA*A9 and gender was observed ([see text]=41.58, P=0.0001). Statistics also revealed heterogeneity of effects among MICA*A5.1/MICA*A9-bearing phenotypes and a dose-dependent effect of MICA*A5.1 and MICA*A9 on NPC risk in male subgroup. This constitutes the first demonstration of a gender-specific association between MICA-STR polymorphism and NPC, which could largely be attributable to the underlying gender-related mechanisms that modulate MICA gene expression. The results provide strong supporting evidence suggesting that MICA*A9 may be a genetic risk factor for NPC in male individuals in this population. The potential interaction between MICA and other non-HLA host factors and environmental exposures remains to be further studied.
In the developing central nervous system (CNS), progenitor cells differentiate into progeny to form functional neural circuits. Radial glial cells (RGs) are a transient progenitor cell type that is present during neurogenesis. It is thought that a combination of neural trophic factors, neurotransmitters and electrical activity regulates the proliferation and differentiation of RGs. However, it is less clear how epigenetic modulation changes RG proliferation. We sought to explore the effect of histone deacetylase (HDAC) activity on the proliferation of RGs in the visual optic tectum of Xenopus laevis. We found that the number of BrdU-labeled precursor cells along the ventricular layer of the tectum decrease developmentally from stage 46 to stage 49. The co-labeling of BrdU-positive cells with brain lipid-binding protein (BLBP), a radial glia marker, showed that the majority of BrdU-labeled cells along the tectal midline are RGs. BLBP-positive cells are also developmentally decreased with the maturation of the brain. Furthermore, HDAC1 expression is developmentally down-regulated in tectal cells, especially in the ventricular layer of the tectum. Pharmacological blockade of HDACs using Trichostatin A (TSA) or Valproic acid (VPA) decreased the number of BrdU-positive, BLBP-positive and co-labeling cells. Specific knockdown of HDAC1 by a morpholino (HDAC1-MO) decreased the number of BrdU- and BLBP-labeled cells and increased the acetylation level of histone H4 at lysine 12 (H4K12). The visual deprivation-induced increase in BrdU- and BLBP-positive cells was blocked by HDAC1 knockdown at stage 49 tadpoles. These data demonstrate that HDAC1 regulates radial glia cell proliferation in the developing optical tectum of Xenopus laevis.
Abstract-We have recently reported that endothelin-1 (ET-1), which is increased in the arteries of deoxycorticosterone acetate (DOCA)-salt hypertensive rats, stimulates superoxide production. However, the humoral mechanisms responsible for ET-1-induced superoxide formation in low-renin models of hypertension, such as DOCA-salt hypertension, remain undefined. Vasopressin is known to upregulate vascular preproET-1 gene expression in DOCA-salt rats, an effect that is absent in vasopressin-deficient Brattleboro rats treated with DOCA-salt. The present study tested the hypothesis that vasopressin contributes to ET-1-induced vascular superoxide production in DOCA-salt hypertensive rats. Carotid arterial segments of DOCA, sham (uninephrectomized), or normal (untreated) rats were used for the study. In vitro vasopressin treatment of carotid arteries from normal rats for 24 hours, but not 4 hours, increased both ET-1 and superoxide levels. The increase of vasopressin-induced superoxide was reduced by pretreatment of the vessels with ABT627, a selective ET A receptor antagonist ABT627. Vasopressin, ET-1, and superoxide levels were significant elevated in carotid arteries of DOCA-salt rats compared with sham controls. The selective V1-vasopressin receptor antagonist (-Mercapto-, -cyclopentamethylenepropiony 1 , O-Me-Tyr 2 , Arg 8 vasopressin, ME-AVP), decreased superoxide both in vasopressin-treated vessels of normal rats and in vessels of DOCA-salt rats, with a concomitant reduction of ET-1 content. These results suggest that vasopressin increases vascular superoxide levels by stimulating ET-1 formation in mineralocorticoid hypertension, and that V1-vasopressin receptors play an important role in this process. Ϫ is produced in activated endothelial cells, 4 smooth muscle cells, 5 and adventitial fibroblasts. 6 Vascular dysfunction is manifested as impaired endothelium-dependent NO-mediated relaxation, 1-3 adhesion molecule expression, 7 low-density lipoprotein oxidation, 8 and cell proliferation. 9 However, the detailed mechanisms responsible for O 2 Ϫ production under different pathophysiological circumstances remain to be defined.We have recently shown that arterial endothelin-1 (ET-1) levels are elevated in deoxycorticosterone acetate (DOCA)-salt hypertension, 10 and that this resulted in increased O 2 Ϫ production 7,10 via ET A receptor activation 10 in this low-renin hypertension model. 11 However, the mechanisms contributing to increased ET-1 are unknown. The peptide hormone 8-argininevasopressin (AVP) is able to stimulate preproendothenlin-1 mRNA expression in arteries and cultured endothelial cells. [12][13][14] Furthermore, the enhanced endothelin gene expression observed in DOCA-salt rats was absent in vasopressin-deficient Brattleboro rats treated with DOCA-salt, 13 suggesting a functional link between vasopressin and ET-1 gene expression.The biological effects of vasopressin are mediated through 2 AVP receptor subtypes, the V 1 and V 2 receptors. 15-17 V 1 receptors mediate vasoconstriction, proliferation, ...
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