Repetitive behavior, a core symptom of autism, encompasses stereotyped responses, restricted interests, and resistance to change. These studies investigated whether different components of the ...repetitive behavior domain could be modeled in the exploratory hole-board task in mice. Four inbred mouse strains, C57BL/6J, BALB/cByJ, BTBR T
+
tf/J, and FVB/NJ, and mice with reduced expression of
Grin1, leading to NMDA receptor hypofunction (
NR1
neo/
neo
mice), were tested for exploration and preference for olfactory stimuli in an activity chamber with a 16-hole floor-board. Reduced exploration and high preference for holes located in the corners of the chamber were observed in BALB/cByJ and BTBR T
+
tf/J mice. All inbred strains had initial high preference for a familiar olfactory stimulus (clean cage bedding). BTBR T
+
tf/J was the only strain that did not demonstrate a shift in hole preference towards an appetitive olfactory stimulus (cereal or a chocolate chip), following home cage exposure to the food. The
NR1
neo/
neo
mice showed lower hole selectivity and aberrant olfactory stimulus preference, in comparison to wildtype controls. The results indicate that
NR1
neo/
neo
mice have repetitive nose poke responses that are less modified by environmental contingencies than responses in wildtype mice. 25–30% of NMDA receptor hypomorphic mice also show self-injurious responses. Findings from the olfactory studies suggest that resistance to change and restricted interests might be modeled in mice by a failure to alter patterns of hole preference following familiarization with an appetitive stimulus, and by high preference persistently demonstrated for one particular olfactory stimulus. Further work is required to determine the characteristics of optimal mouse social stimuli in the olfactory hole-board test.
MUC2 is a secretory mucin normally expressed by goblet cells of the intestinal epithelium. It is overexpressed in mucinous type colorectal cancers but down-regulated in colorectal adenocarcinoma. ...Phorbol 12-myristate 13-acetate (PMA) treatment of colon cancer cell lines increases MUC2 expression, so we have undertaken a detailed analysis of the effects of PMA on the promoter activity of the 5'-flanking region of the MUC2 gene using stably and transiently transfected promoter reporter vectors. Protein kinase C inhibitors (bisindolylmaleimide, calphostin C) and inhibitors of mitogen-activated protein/extracellular signal regulated kinase kinase (MEK) (PD98059 and U0126) suppressed up-regulation of MUC2. Src tyrosine kinase inhibitor PP2, a protein kinase A inhibitor (KT5720), and a p38 inhibitor (SB 203580) did not affect transcription. Western blotting and reverse transcription-PCR analysis confirmed these results. In addition, co-transfections with mutants of Ras, Raf, and MEK showed that the induction of MUC2 promoter activity by PMA required these three signaling proteins. Our results demonstrate that PMA activates protein kinase C, stimulating MAP kinase through a Ras- and Raf-dependent mechanism. An important role for nuclear factor kappaB (NF-kappaB) was also demonstrated using the inhibitor caffeic acid phenethyl ester and electrophoretic mobility shift assays. Such identification of pathways involved in MUC2 up-regulation by PMA in the HM3 colon cancer cell line may serve as a model for the effects of cytokines and growth factors, which regulate MUC2 expression during the progression of colorectal cancer.
•Patients with chronic ITP had clonal expansions of disease-associated TEMRA CD8+ T cells.•CD8+ T cells bind to platelets and cause their activation and apoptosis, defining an antibody-independent ...mechanism of platelet destruction.
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Immune thrombocytopenia (ITP) is traditionally considered an antibody-mediated disease. However, a number of features suggest alternative mechanisms of platelet destruction. In this study, we use a multidimensional approach to explore the role of cytotoxic CD8+ T cells in ITP. We characterized patients with ITP and compared them with age-matched controls using immunophenotyping, next-generation sequencing of T-cell receptor (TCR) genes, single-cell RNA sequencing, and functional T-cell and platelet assays. We found that adults with chronic ITP have increased polyfunctional, terminally differentiated effector memory CD8+ T cells (CD45RA+CD62L−) expressing intracellular interferon gamma, tumor necrosis factor α, and granzyme B, defining them as TEMRA cells. These TEMRA cells expand when the platelet count falls and show no evidence of physiological exhaustion. Deep sequencing of the TCR showed expanded T-cell clones in patients with ITP. T-cell clones persisted over many years, were more prominent in patients with refractory disease, and expanded when the platelet count was low. Combined single-cell RNA and TCR sequencing of CD8+ T cells confirmed that the expanded clones are TEMRA cells. Using in vitro model systems, we show that CD8+ T cells from patients with ITP form aggregates with autologous platelets, release interferon gamma, and trigger platelet activation and apoptosis via the TCR-mediated release of cytotoxic granules. These findings of clonally expanded CD8+ T cells causing platelet activation and apoptosis provide an antibody-independent mechanism of platelet destruction, indicating that targeting specific T-cell clones could be a novel therapeutic approach for patients with refractory ITP.
The importance of cytotoxic T cells has been recognized in chronic immune thrombocytopenia (ITP), yet how CD8+ T cells evolve and perpetuate chronic ITP is a mystery. This month’s CME article, a Plenary Paper by Malik and colleagues, demonstrates that in chronic ITP, there is clonal expansion of a particular subset of CD8+ T cells, known as terminally differentiated effector memory T cells, which persist over years, are more evident in refractory ITP, and are more prevalent when the platelet count is low. Furthermore, CD8+ T cells induce platelet activation and apoptosis in an antibody-independent mechanism for refractory thrombocytopenia that may be amenable to therapeutic targeting.
The BaBar RadFET monitoring board Camanzi, B.; Crawley, H.B.; Holmes-Siedle, A. ...
IEEE transactions on nuclear science,
06/2002, Letnik:
49, Številka:
3
Journal Article
Recenzirano
The monitoring board to interface the RadFET integrated radiation dosimeters to the BaBar detector control system is described. RadFET sensors are specially designed p-channel MOSFET transistors that ...measure lifetime integrated radiation exposure by measuring the source-drain voltage at a fixed current. As the device is irradiated, positive space charge is trapped in the oxide layer, which results in an increase in the source-drain voltage. Communication with the BaBar detector control system proceeds via a CANbus interface using a Motorola microcontroller on the monitoring board and the BaBar standard monitoring tools on the BaBar side. The RadFET monitoring board (RMB) can read up to 32 sensors. A manual control allows for adjustment of an offset voltage to increase the maximum readable value as the device receives more exposure while retaining the original circuit precision. Results from monitoring during the first years of BaBar running are presented.
Background
Bone morphogenetic and activin membrane‐bound inhibitor (BAMBI) is a transmembrane protein related to the type I transforming growth factor‐ β (TGF‐β) receptor family that is present on ...both platelets and endothelial cells (ECs). Bambi‐deficient mice exhibit reduced hemostatic function and thrombus stability characterized by an increased embolization.
Objective
We aimed to delineate how BAMBI influences endothelial function and thrombus stability.
Methods
Bambi‐deficient mice were subjected to the laser‐induced thrombosis model where platelet and fibrin accumulation was evaluated. Expression of thrombomodulin and tissue factor pathway inhibitor (TFPI) was also assessed in these mice.
Results
Thrombus instability in Bambi−/− mice was associated with a profound defect in fibrin deposition. Injection of hirudin into Bambi+/+ mice prior to thrombus formation recapitulated the Bambi−/− thrombus instability phenotype. In contrast, hirudin had no additional effect upon thrombus formation in Bambi−/− mice. Deletion of Bambi in ECs resulted in mice with defective thrombus stability caused by decreased fibrin accumulation. Increased levels of the anticoagulant proteins TFPI and thrombomodulin were detected in Bambi−/− mouse lung homogenates. Endothelial cells isolated from Bambi−/− mouse lungs exhibited enhanced ability to activate protein C due to elevated thrombomodulin levels. Blocking thrombomodulin and TFPI in vivo fully restored fibrin accumulation and thrombus stability in Bambi−/−mice.
Conclusions
We demonstrate that endothelial BAMBI influences fibrin generation and thrombus stability by modulating thrombomodulin and TFPI anticoagulant function of the endothelium; we also highlight the importance of these anticoagulant proteins in the laser‐induced thrombosis model.
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