108 research outputs found
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Pyk2 activates the NLRP3 inflammasome by directly phosphorylating ASC and contributes to inflammasome-dependent peritonitis
The inflammasome adaptor protein, ASC, contributes to both innate immune responses and inflammatory diseases via self-oligomerization, which leads to the activation of the protease, caspase-1. Here, we report that the cytosolic tyrosine kinases, FAK and Pyk2, are differentially involved in NLRP3 and AIM2 inflammasome activation. The inhibition of FAK and Pyk2 with RNA interference or chemical inhibitors dramatically abolished ASC oligomerization, caspase-1 activation, and IL-1Ξ² secretion in response to NLRP3 or AIM2 stimulation. Pyk2 is phosphorylated by the kinase Syk and relocalizes to the ASC specks upon NLRP3 inflammasome activation. Pyk2, but not FAK, could directly phosphorylate ASC at Tyr146, and only the phosphorylated ASC could participate in speck formation and trigger IL-1Ξ² secretion. Moreover, the clinical-trial-tested Pyk2/FAK dual inhibitor PF-562271 reduced monosodium urate-mediated peritonitis, a disease model used for studying the consequences of NLRP3 activation. Our results suggest that although Pyk2 and FAK are involved in inflammasome activation, only Pyk2 directly phosphorylates ASC and brings ASC into an oligomerization-competent state by allowing Tyr146 phosphorylation to participate ASC speck formation and subsequent NLRP3 inflammation
Immobilization of enzyme and antibody on ALD-HfO2-EIS structure by NH3 plasma treatment
Thin hafnium oxide layers deposited by an atomic layer deposition system were investigated as the sensing membrane of the electrolyte-insulator-semiconductor structure. Moreover, a post-remote NH3 plasma treatment was proposed to replace the complicated silanization procedure for enzyme immobilization. Compared to conventional methods using chemical procedures, remote NH3 plasma treatment reduces the processing steps and time. The results exhibited that urea and antigen can be successfully detected, which indicated that the immobilization process is correct
Dysfunction of the noradrenergic system drives inflammation, Ξ±-synucleinopathy, and neuronal loss in mouse colon
Clinical and pathological evidence revealed that Ξ±-synuclein (Ξ±-syn) pathology seen in PD patients starts in the gut and spreads via anatomically connected structures from the gut to the brain. Our previous study demonstrated that depletion of central norepinephrine (NE) disrupted brain immune homeostasis, producing a spatiotemporal order of neurodegeneration in the mouse brain. The purpose of this study was 1) to determine the role of peripheral noradrenergic system in the maintenance of gut immune homeostasis and in the pathogenesis of PD and 2) to investigate whether NE-depletion induced PD-like Ξ±-syn pathological changes starts from the gut. For these purposes, we investigated time-dependent changes of Ξ±-synucleinopathy and neuronal loss in the gut following a single injection of DSP-4 (a selective noradrenergic neurotoxin) to A53T-SNCA (human mutant Ξ±-syn) over-expression mice. We found DPS-4 significantly reduced the tissue level of NE and increased immune activities in gut, characterized by increased number of phagocytes and proinflammatory gene expression. Furthermore, a rapid-onset of Ξ±-syn pathology was observed in enteric neurons after 2 weeks and delayed dopaminergic neurodegeneration in the substantia nigra was detected after 3-5 months, associated with the appearance of constipation and impaired motor function, respectively. The increased Ξ±-syn pathology was only observed in large, but not in the small, intestine, which is similar to what was observed in PD patients. Mechanistic studies reveal that DSP-4-elicited upregulation of NADPH oxidase (NOX2) initially occurred only in immune cells during the acute intestinal inflammation stage, and then spread to enteric neurons and mucosal epithelial cells during the chronic inflammation stage. The upregulation of neuronal NOX2 correlated well with the extent of Ξ±-syn aggregation and subsequent enteric neuronal loss, suggesting that NOX2-generated reactive oxygen species play a key role in Ξ±-synucleinopathy. Moreover, inhibiting NOX2 by diphenyleneiodonium or restoring NE function by salmeterol (a Ξ²2-receptor agonist) significantly attenuated colon inflammation, Ξ±-syn aggregation/propagation, and enteric neurodegeneration in the colon and ameliorated subsequent behavioral deficits. Taken together, our model of PD shows a progressive pattern of pathological changes from the gut to the brain and suggests a potential role of the noradrenergic dysfunction in the pathogenesis of PD
Secretome-Based Identification of ULBP2 as a Novel Serum Marker for Pancreatic Cancer Detection
BACKGROUND: To discover novel markers for improving the efficacy of pancreatic cancer (PC) diagnosis, the secretome of two PC cell lines (BxPC-3 and MIA PaCa-2) was profiled. UL16 binding protein 2 (ULBP2), one of the proteins identified in the PC cell secretome, was selected for evaluation as a biomarker for PC detection because its mRNA level was also found to be significantly elevated in PC tissues. METHODS: ULBP2 expression in PC tissues from 67 patients was studied by immunohistochemistry. ULBP2 serum levels in 154 PC patients and 142 healthy controls were measured by bead-based immunoassay, and the efficacy of serum ULBP2 for PC detection was compared with the widely used serological PC marker carbohydrate antigen 19-9 (CA 19-9). RESULTS: Immunohistochemical analyses revealed an elevated expression of ULPB2 in PC tissues compared with adjacent non-cancerous tissues. Meanwhile, the serum levels of ULBP2 among all PC patients (nβ=β154) and in early-stage cancer patients were significantly higher than those in healthy controls (p<0.0001). The combination of ULBP2 and CA 19-9 outperformed each marker alone in distinguishing PC patients from healthy individuals. Importantly, an analysis of the area under receiver operating characteristic curves showed that ULBP2 was superior to CA 19-9 in discriminating patients with early-stage PC from healthy controls. CONCLUSIONS: Collectively, our results indicate that ULBP2 may represent a novel and useful serum biomarker for pancreatic cancer primary screening
From discovery of tyrosine phosphorylation to targeted cancer therapies: The 2018 Tang Prize in Biopharmaceutical Science
Protein tyrosine kinases (TKs) are a family of enzymes that catalyze the phosphorylation of proteins at tyrosine residues. TKs play key roles in controlling cell growth and many other functions by modulating the status of tyrosine phosphorylation of regulatory proteins critical for numerous cellular signaling pathways. Dysregulation of TKs caused by genetic abnormalities (mutation, amplification, fusion, etc.) results in uncontrolled cell growth, and ultimately leads to cancer. Thus, identification of dysregulated TK(s) in a specific cancer type and development of TK inhibitors (TKIs) that can potently block activity of the dysregulated TK establish the foundation of modern targeted cancer therapies. The 2018 Tang Prize in Biopharmaceutical Science was awarded to Tony Hunter as well as Brian Druker and John Mendelsohn for their great contributions in discovering oncogene src as a TK and developing small molecule TKIs or therapeutic monoclonal antibodies against receptor TK, respectively. Keywords: Tyrosine phosphorylation, Oncogene, Tyrosine kinase inhibitor, Targeted cancer therapy, 2018 Tang Priz
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Confocal Microscopy Study of Neurovascular Distribution in Facial Port Wine Stains (Capillary Malformation) (vol 107, pg 559, 2008)
Retraction of βConfocal Microscopy Study of Neurovascular Distribution in Facial Port Wine Stains (Capillary Malformation)β [J Formos Med Assoc 2008;107(7):559β566] by
Ochratoxin a inhibits mouse embryonic development by activating a mitochondrion-dependent apoptotic signaling pathway
Abstract: Ochratoxin A (OTA), a mycotoxin found in many foods worldwide, causes nephrotoxicity, hepatotoxicity, and immunotoxicity, both in vitro and in vivo. In the present study, we explored the cytotoxic effects exerted by OTA on the blastocyst stage of mouse embryos, on subsequent embryonic attachment, on outgrowth in vitro, and following in vivo implantation via embryo transfer. Mouse blastocysts were incubated with or without OTA (1, 5, or 10 ΞΌM) for 24 h. Cell proliferation and growth were investigated using dual differential staining; apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay; and embryo implantation and post-implantation development were assessed by examination of in vitro growth and the outcome of in vivo embryo transfer, respectively. Blastocysts treated with 10 ΞΌM OTA displayed a significantly increased level of apoptosis and a reduction in total cell number. Interestingly, we observed no marked difference in implantation success rate between OTA-pretreated and control blastocysts either during in vitro embryonic development (following implantation in a fibronectin-coated culture dish) or after in vivo embryo transfer. However, in vitro treatment with 10 ΞΌM OTA wasInt. J. Mol. Sci. 2013, 14 93
Apoptotic signalling cascade in photosensitized human epidermal carcinoma A431 cells: involvement of singlet oxygen, c-Jun N-terminal kinase, caspase-3 and p21-activated kinase 2
On Appeal From the Judgment of the Fifth Judicial District Court in and for Washington County, State of Utah. Honorable James L. Shumate
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