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The contribution of the acute phase response to the pathogenesis of relapse in chronic-relapsing experimental autoimmune encephalitis models of multiple sclerosis.
BACKGROUND: Increased relapse rates in multiple sclerosis (MS) as a consequence of peripheral immune system activation, owing to infection for example, have been widely reported, but the mechanism remains unclear. Acute brain injury models can be exacerbated by augmenting the hepatic acute phase response (APR). Here, we explored the contribution of the hepatic APR to relapse in two rodent models of MS. METHODS: Mice with MOG-CFA-induced chronic relapsing experimental autoimmune encephalitis (CR-EAE) were killed before, during and after the first phase of disease, and the brain and liver chemokine, cytokine and acute phase protein (APP) mRNA expression profile was determined. During remission, the APR was reactivated with an intraperitoneal lipopolysaccharide (LPS) and clinical score was monitored throughout. To explore the downstream mediators, CXCL-1, which is induced as part of the APR, was injected into animals with a focal, cytokine/MOG-induced EAE lesion (fEAE) and the cellularity of the lesions was assessed. RESULTS: Compared to CFA control, in a rodent CR-EAE model, an hepatic APR preceded clinical signs and central cytokine production in the initial phase of disease. Compared to administration in naïve animals, an LPS challenge during the asymptomatic remission phase of CR-EAE rodents provoked relapse and resulted in the increased and extended expression of specific peripheral hepatic chemokines. CXCL-1 and several other APPs were markedly elevated. A single intravenous administration of the highly induced chemokine, CXCL-1, was found to be sufficient to reactivate the lesions by increasing microglial activation and the recruitment of T cells in fEAE lesions. CONCLUSIONS: The APR plays a contributing role to the pathology seen in models of chronic brain injury and in translating the effects of peripheral immune system stimulation secondary to trauma or infection into central pathology and behavioural signs. Further elucidation of the exact mechanisms in this process will inform development of more effective, selective therapies in MS that, by suppressing the hepatic chemokine response, may prevent relapse.
Circulating endothelial cell-derived extracellular vesicles mediate the acute phase response and sickness behaviour associated with CNS inflammation.
Brain injury elicits a systemic acute-phase response (APR), which is responsible for co-ordinating the peripheral immunological response to injury. To date, the mechanisms responsible for signalling the presence of injury or disease to selectively activate responses in distant organs were unclear. Circulating endogenous extracellular vesicles (EVs) are increased after brain injury and have the potential to carry targeted injury signals around the body. Here, we examined the potential of EVs, isolated from rats after focal inflammatory brain lesions using IL-1β, to activate a systemic APR in recipient naïve rats, as well as the behavioural consequences of EV transfer. Focal brain lesions increased EV release, and, following isolation and transfer, the EVs were sequestered by the liver where they initiated an APR. Transfer of blood-borne EVs from brain-injured animals was also enough to suppress exploratory behaviours in recipient naïve animals. EVs derived from brain endothelial cell cultures treated with IL-1β also activated an APR and altered behaviour in recipient animals. These experiments reveal that inflammation-induced circulating EVs derived from endothelial cells are able to initiate the APR to brain injury and are sufficient to generate the associated sickness behaviours, and are the first demonstration that EVs are capable of modifying behavioural responses.
Endothelium-derived extracellular vesicles promote splenic monocyte mobilization in myocardial infarction.
Transcriptionally activated monocytes are recruited to the heart after acute myocardial infarction (AMI). After AMI in mice and humans, the number of extracellular vesicles (EVs) increased acutely. In humans, EV number correlated closely with the extent of myocardial injury. We hypothesized that EVs mediate splenic monocyte mobilization and program transcription following AMI. Some plasma EVs bear endothelial cell (EC) integrins, and both proinflammatory stimulation of ECs and AMI significantly increased VCAM-1-positive EV release. Injected EC-EVs localized to the spleen and interacted with, and mobilized, splenic monocytes in otherwise naive, healthy animals. Analysis of human plasma EV-associated miRNA showed 12 markedly enriched miRNAs after AMI; functional enrichment analyses identified 1,869 putative mRNA targets, which regulate relevant cellular functions (e.g., proliferation and cell movement). Furthermore, gene ontology termed positive chemotaxis as the most enriched pathway for the miRNA-mRNA targets. Among the identified EV miRNAs, EC-associated miRNA-126-3p and -5p were highly regulated after AMI. miRNA-126-3p and -5p regulate cell adhesion- and chemotaxis-associated genes, including the negative regulator of cell motility, plexin-B2. EC-EV exposure significantly downregulated plexin-B2 mRNA in monocytes and upregulated motility integrin ITGB2. These findings identify EVs as a possible novel signaling pathway by linking ischemic myocardium with monocyte mobilization and transcriptional activation following AMI.
Protease expression in experimental colitis
Extracellular matrix (ECM) is degraded by matrix metalloproteinases, collagenase, stromelysin and gelatinase, whose activity is strictly controlled by tissue inhibitor of metalloproteinase (TIMP). Excessive enzyme activity could lead to tissue destruction in inflammatory bowel disease (IBD). Using a rabbit model of chronic colitis we investigated the temporal and spatial distribution of these enzymes by immunolocalisation. 72 kD intracellular gelatinase was observed 3 h after initiation of colitis. At 6 h and 12 h, collagenase and, to a lesser extent, 72 kD and 95 kD gelatinase and stromelysin were all observed on the ECM in regions of mucosal ulceration. TIMP, however, was absent at these earlier times suggesting uncontrolled degradation of ECM, but by 24 h, it was expressed in mucosa adjacent to areas of ulceration. At 72 h and after one week, expression of collagenase declined and from two weeks until the ulcers resolved, stromelysin and gelatinase were found at the junction of normal and ulcerated tissue. TIMP expression remained constant until ulceration had healed at 6 weeks. In colon from animals killed at 0 h, no enzyme or TIMP expression was observed. Collagenase appears to be associated with the acute phase of ulcer formation, whereas stromelysin and gelatinase are predominant during healing. © 1994 Birkhäuser Verlag.
IGF2 mRNA binding protein-2 is a tumor promoter that drives cancer proliferation through its client mRNAs IGF2 and HMGA1.
The gene encoding the Insulin-like Growth Factor 2 mRNA binding protein 2/IMP2 is amplified and overexpressed in many human cancers, accompanied by a poorer prognosis. Mice lacking IMP2 exhibit a longer lifespan and a reduced tumor burden at old age. Herein we show in a diverse array of human cancer cells that IMP2 overexpression stimulates and IMP2 elimination diminishes proliferation by 50-80%. In addition to its known ability to promote the abundance of Insulin-like Growth Factor 2/IGF2, we find that IMP2 strongly promotes IGF action, by binding and stabilizing the mRNA encoding the DNA binding protein HMGA1, a known oncogene. HMGA1 suppresses the abundance of IGF binding protein 2/IGFBP2 and Grb14, inhibitors of IGF action. IMP2 stabilization of HMGA1 mRNA plus IMP2 stimulated IGF2 production synergistically drive cancer cell proliferation and account for IMP2's tumor promoting action. IMP2's ability to promote proliferation and IGF action requires IMP2 phosphorylation by mTOR.
N-Butyl-l-deoxynojirimycin (l-NBDNJ): Synthesis of an Allosteric Enhancer of α-Glucosidase Activity for the Treatment of Pompe Disease.
The highly stereocontrolled de novo synthesis of l-NBDNJ (the unnatural enantiomer of the iminosugar drug Miglustat) and a preliminary evaluation of its chaperoning potential are herein reported. l-NBDNJ is able to enhance lysosomal α-glucosidase levels in Pompe disease fibroblasts, either when administered singularly or when coincubated with the recombinant human α-glucosidase. In addition, differently from its d-enantiomer, l-NBDNJ does not act as a glycosidase inhibitor.
Left thoracoabdominal esophagectomy: results from a single specialist center.
The left thoracoabdominal approach to esophagectomy is not widely performed, despite offering excellent exposure to tumors of the esophagogastric junction. Criticisms of the approach have focused on historically high rates of mortality, complications, and positive resection margins. Our aim was to determine whether left thoracoabdominal esophagectomy could combine a radical oncological resection with acceptably low mortality and morbidity. A retrospective cohort study of all left thoracoabdominal esophagectomies was performed at a single specialist center over an 11-year period. Primary outcomes were in-hospital mortality, complications, resection margin involvement, and lymph node yield; secondary outcomes were 1-year and 5-year survival. Two hundred eleven esophagectomies were performed. In-hospital mortality was 5.7% (12/211). One hundred one subjects (47.9%) had an uncomplicated recovery; 110 subjects (52.1%) developed at least one complication. There were 15 clinically significant anastomotic leaks (7.1%). Twenty-four subjects (11.4%) required emergency reoperation, the most common indication being anastomotic leakage. Complete tumor excision (R0 resection) was achieved in 151 of 211 cases (71.6%); median lymph node yield was 24. One-year and 5-year survival rates were 70% (147/211) and 21% (24/116), respectively. Left thoracoabdominal esophagectomy can combine a radical oncological resection with acceptably low mortality and morbidity.
Modifiable factors influencing relatives' decision to offer organ donation: systematic review.
OBJECTIVE: To identify modifiable factors that influence relatives' decision to allow organ donation. DESIGN: Systematic review. DATA SOURCES: Medline, Embase, and CINAHL, without language restriction, searched to April 2008. Review methods Three authors independently assessed the eligibility of the identified studies. We excluded studies that examined only factors affecting consent that could not be altered, such as donor ethnicity. We extracted quantitative results to an electronic database. For data synthesis, we summarised the results of studies comparing similar themes. RESULTS: We included 20 observational studies and audits. There were no randomised controlled trials. The main factors associated with reduced rates of refusal were the provision of adequate information on the process of organ donation and its benefits; high quality of care of potential organ donors; ensuring relatives had a clear understanding of brain stem death; separating the request for organ donation from notification that the patient had died; making the request in a private setting; and using trained and experienced individuals to make the request. CONCLUSIONS: Limited evidence suggests that there are modifiable factors in the process of requests for organ donation, in particular the skills of the individual making the request and the timing of this conversation, that might have a significant impact on rates of consent. Targeting these factors might have a greater and more immediate effect on the number of organs for donation than legislative or other long term strategies.
Child Protection Training
With new definitions in child protection ranging from child sexual exploitation, gang violence, radicalisation and internet bullying through to female genital mutilation, witchcraft and spirit possession, honour based violence and forced ...