Eosinophilic Esophagitis (EoE) is a chronic allergic disorder, whose pathobiology is incompletely understood. Histamine-producing cells including mast cells and basophils have been implicated in EoE. However, very little is currently known about the role of histamine and histamine receptor (HR) expression and signaling in the esophageal epithelium. Herein, we characterized HR (H1R, H2R, H3R, and H4R) expression in human esophageal biopsies and investigate the role of histamine signaling in inducible cytokine expression in human esophageal epithelial cells in vitro. HR expression was quantified in esophageal biopsies from non-EoE control (N = 23), inactive EoE (<15 eos/hpf, N = 26) and active EoE (>15 eos/hpf, N = 22) subjects using qRT-PCR and immunofluorescent localization. HR expression and histamine-mediated cytokine secretion were evaluated in human primary and telomerase-immortalized esophageal epithelial cells. H1R, H2R, and H4R expression were increased in active EoE biopsies compared to inactive EoE and controls. H2R was the most abundantly expressed receptor, and H3R expression was negligible in all 3 cohorts. Infiltrating eosinophils expressed H1R, H2R, and H4R, which contributed to the observed increase in HR in active subjects. H1R and H2R, but not H3R or H4R, were constitutively expressed by primary and immortalized cells, and epithelial histamine stimulation induced GM-CSF, TNFα, and IL-8, but not TSLP or eotaxin-3 secretion. Epithelial priming with the TLR3 ligand poly (I:C) induced H1R and H2R expression, and enhanced histamine-induced GM-CSF, TNFα, and IL-8 secretion. These effects were primarily suppressed by H1R antagonists, but unaffected by H2R antagonism. Histamine directly activates esophageal epithelial cytokine secretion in vitro in an H1R dependent fashion. However, H1R, H2R and H4R are induced in active inflammation in EoE in vivo. While systemic antihistamine (anti-H1R) therapy may not induce clinical remission in EoE, our study suggests that further study of histamine receptor signaling in EoE is warranted and that targeting of additional histamine receptors may lead to novel treatment strategies for this important disease. 相似文献
Certain missense mutations in optineurin/OPTN and amplification of TBK1 are associated with normal tension glaucoma. A glaucoma-associated variant of OPTN, M98K, induces autophagic degradation of transferrin receptor (TFRC) and death in retinal cells. Here, we have explored the role of Tbk1 in M98K-OPTN-induced autophagy and cell death, and the effect of Tbk1 overexpression in retinal cells. Cell death induced by M98K-OPTN was dependent on Tbk1 as seen by the effect of Tbk1 knockdown and blocking of Tbk1 activity by a chemical inhibitor. Inhibition of Tbk1 also restores M98K-OPTN-induced transferrin receptor degradation. M98K-OPTN-induced autophagosome formation, autophagy and cell death were dependent on its phosphorylation at S177 by Tbk1. Knockdown of OPTN reduced starvation-induced autophagosome formation. M98K-OPTN expressing cells showed higher levels of Tbk1 activation and enhanced phosphorylation at Ser177 compared to WT-OPTN expressing cells. M98K-OPTN-induced activation of Tbk1 and its ability to be phosphorylated better by Tbk1 was dependent on ubiquitin binding. Phosphorylated M98K-OPTN localized specifically to autophagosomes and endogenous Tbk1 showed increased localization to autophagosomes in M98K-OPTN expressing cells. Overexpression of Tbk1 induced cell death and caspase-3 activation that were dependent on its catalytic activity. Tbk1-induced cell death possibly involves autophagy, as shown by the effect of Atg5 knockdown, and requirement of autophagic function of OPTN. Our results show that phosphorylation of Ser177 plays a crucial role in M98K-OPTN-induced autophagosome formation, autophagy flux and retinal cell death. In addition, we provide evidence for cross talk between two glaucoma associated proteins and their inter-dependence to mediate autophagy-dependent cell death. 相似文献
AbstractGlutamine synthetase (GS) of Mycobacterium tuberculosis (Mtb) is an essential enzyme which is involved in nitrogen metabolism and cell wall synthesis. It is involved in the inhibition of phagosome-lysosome fusion by preventing acidification. Targeting GS can be helpful to control the infection of Mtb. In order to identify potential inhibitors, we screened chemical libraries (56,400 compounds of ChEMBL anti-mycobacterial, 1596 FDA approved drugs, 419 Natural product and 916 phytochemical) against this target using the virtual screening approach. Screening by molecular docking identified ten top-ranked compounds as GSMtb inhibitors and they were compared with known inhibitors (as control). Since GS enzyme (GSHs) is also present in human. We have compared the protein sequence of GS from Mtb and human using the P-BLAST in NCBI. We found ~27% identity in between these two sequences, so we also compared the binding affinity of inhibitor between Mtb and human. Finally, we identified top two compounds namely CHEMBL387509, CHEMBL226198 from ChEMBL anti-mycobacterial dataset, and Eriocitrin and Malvidin from phytochemical dataset which showed lees binding affinity towards GSHs whereas Pamidronate, and Phentermine from FDA approved drugs and (-)-Quinic Acid, Hexopyranuronic acid, Quebrachit, and Castanospermine from natural product showed protein-ligand interaction with Mtb protein while no interaction with GSHs. The top two docked complexes were subjected to molecular dynamic simulation to understand the stability of the molecule. Further, we calculated the binding free energy of the docked complex and analyzed hydrogen bond, salt bridge, pie stacking, and hydrophobic interaction in the docking region. These ligands exhibited very good binding affinity GSMtb enzymes. Therefore, these ligands are novel and drug-likeness compounds, and they may be potential inhibitors of M tuberculosis.Communicated by Ramaswamy H. Sarma 相似文献
The North-Eastern Himalayan (NEH) region of India is endowed with rich maize genetic resources which is important from both genetics and evolutionary viewpoints. Mimban landrace of maize is a popular choice in Mizoram as food among the locals due to its stickiness caused by recessive wx1 gene resulting in high amylopectin in the grains. In the present study, a set of 24 Mimban accessions possessing high amylopectin (mean 89.72%, range 80.2–93.7%) content were analyzed. 93 SSRs markers generated a total of 334 alleles with a range of 2–9 and mean of 3.59 alleles per locus. Polymorphism information content varied from 0.117 to 0.829 with an average of 0.528. A total of 20 unique and 24 rare alleles were detected. Twenty-seven major alleles with individual frequencies exceeding 0.70 were also identified across the accessions. Cluster analyses classified 24 genotypes into three major clusters each having 2, 14 and 9 accessions. The clustering pattern was largely congruent with the geographical information. Diverse origin of the accessions was also depicted by the SSR based principal coordinate analysis. These accessions with high amylopectin content from diverse clusters may be crossed to derive heterotic hybrid and also might be used for novel gene identification. Thus information generated here possesses great potential in their utilization in the waxy corn genomics and breeding and emphasizes the need for further exploration of unique trait specific genepool from unexplored areas. This is the first report of molecular characterization of Mimban landrace accessions from NEH region.
The chewing of betel leaf with other ingredients is a widespread addiction in India. The chromosome damaging effect was studied in human leukocyte cultures. There was an increase in the frequency of chromatid aberrations when the leaf extract was added to cultures. 相似文献
The present study is aimed to evaluate the putative neuroprotective effect of quercetin on PCB induced impairment of dopaminergic
receptor mRNA expression in cerebral cortex of adult male Wistar rats. Group I (control) received only vehicle (corn oil;
0.1 ml/kg bwt) intraperitoneally (i.p); Group II Aroclor 1254 at a dose of 2 mg/kg bwt/day (i.p); Group III (Aroclor 1254—exposed
(i.p), quercetin treated gavage (50 mg/kg bwt/day); Group IV received quercetin alone (gavage). 24 h after the 30th day treatment
rats were euthanized. From each rat cerebral cortex tissues was collected and analyzed for mean activities of creatine kinase,
acetylcholine esterase, Na+/K+, Ca2+ and Mg2+ATPases, Hydrogen peroxide generation, protein carbonyl content and lipid peroxidation levels. The fates of the mRNA expression
of dopaminergic receptors, Cacna1d on all the groups were studied by RT–PCR. Results evidenced that significant reduction
of neurodegeneration in PCBs exposed rats treated with quercetin was ascertained suggesting, quercetin treatment precludes
against PCB induced oxidative stress and protects dopaminergic receptor dysfunction in rat cerebral cortex. 相似文献
Detection of Insulin resistance (IR) in normoglycemic young subjects before the onset of Impaired Glucose Tolerance (IGT)
is of importance as it affords implementation of preventive measures in such high risk subject. Very few studies have specifically
evaluated for the presence of IR in younger age group with normal glucose tolerance. The gold standard for investigating and
quantifying insulin resistance is the “hyperinsulinemic euglycemic clamp,” the complicated nature of the “clamp” technique,
alternatives have been sought to simplify the measurement of insulin resistance. The oral glucose tolerance test (OGTT) is
one of the most commonly used methods to evaluate whole body glucose tolerance in vivo. IR and IS values of HOMA-IR, ISI0–120, QUICKIE mathematical models derived from OGTT have been shown to produce equivalent results as in Euglycemic clamp technique
we hypothesized that normoglycemic young adult who are siblings of type II diabetics (SD) probably have higher IR values than
the siblings of non diabetics as they are genetically predisposed. 相似文献