Citations

Vascular endothelial growth factor (VEGF)-induced receptor phosphorylation is the crucial step for initiating downstream signaling pathways that lead to angiogenesis or related pathophysiological outcomes. Our previous studies have shown that the neurotransmitter dopamine could inhibit VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR-2), endothelial cell proliferation, migration, microvascular permeability, and thus, angiogenesis. In this study, we address the mechanism by which VEGFR-2 phosphorylation is regulated by dopamine. Here, we demonstrate that D2 dopamine receptor (D2DR) colocalizes with VEGFR-2 at the cell surface. Dopamine pretreatment increases the translocation and colocalization of Src-homology-2-domain-containing protein tyrosine phosphatase (SHP-2) with D2DR at the cell surface. Dopamine administration leads to increased VEGF-induced phosphorylation of SHP-2 and this increased phosphorylation parallels the increased phosphatase activity of SHP-2. Active SHP-2 then dephosphorylates VEGFR-2 at Y951, Y996 and Y1059, but not Y1175. We also observe that SHP-2 knockdown impairs the dopamine-regulated inhibition of VEGF-induced phosphorylation of VEGFR-2 and, subsequently, Src phosphorylation and migration. Our data establish a novel role for SHP-2 phosphatase in the dopamine-mediated regulation of VEGFR-2 phosphorylation.

ABSTRACTEosinophils are best known as the predominant cellular infiltrate associated with asthma and parasitic infections. Recently, numerous studies have documented the presence of Toll-like receptors (TLRs) on the surfaces of eosinophils, suggesting that these leukocytes may participate in the recognition and killing of viruses and bacteria. However, the significance of this role in the innate immune response to bacterial infection is largely unknown. Here we report a novel role for eosinophils as antibacterial defenders in the host response. Isolated mouse eosinophils possessed antipseudomonal properties in vitro. In vivo, interleukin-5 transgenic mice, which have profound eosinophilia, demonstrated improved clearance ofPseudomonas aeruginosaintroduced into the peritoneal cavity. The findings of improved bacterial clearance following adoptive transfer of eosinophils, and impaired bacterial clearance in mice with a congenital eosinophil deficiency, established that this effect was eosinophil specific. The data presented also demonstrate that eosinophils mediate this antibacterial effect in part through the release of cationic secondary granule proteins. Specifically, isolated eosinophil granules had antibacterial properties in vitro, and administration of eosinophil granule extracts significantly improved bacterial clearance in vivo. These data suggest a potent yet underappreciated antibacterial role for eosinophils in vivo, specifically for eosinophil granules. Moreover, the data suggest that the administration of eosinophil-derived products may represent a viable adjuvant therapy for septic or bacteremic patients in the intensive care unit.

Object The purpose of this study was to evaluate the incidence of seizures or epileptiform abnormalities on electroencephalography (EEG) studies in patients undergoing surgical treatment for acute subdural hematoma (SDH). Methods This was a retrospective study of 134 consecutive patients with acute or acute-on-chronic SDH who underwent surgical treatment at the authors' institution between January 2004 and July 2008. Detailed information was collected regarding baseline clinical data (including preexistent functional impairment); Glasgow Coma Scale (GCS) sum scores before and 24 hours after surgery; presence of clinical seizures; EEG findings; and functional outcome on discharge and up to the 6-month follow-up. All brain CT scans were reviewed to calculate SDH volume and midline shift. The Glasgow Outcome Scale (GOS) score was used for functional assessment, and GOS scores of 1–3 were considered indicative of poor outcome. Univariate and multivariate logistic regression analyses were performed to identify statistical associations. Results Clinical seizures or epileptiform changes on EEG were observed during the acute postoperative period in 33 patients (25%). Preexistent functional impairment and seizures/epileptiform EEG findings after surgery were independently associated with poor functional outcome upon hospital discharge (p < 0.001 for both). Preexistent functional impairment (p < 0.001), lower GCS score before surgery (p = 0.04), and lower GCS score 24 hours after surgery (p = 0.007), but not seizures/epileptiform EEG findings, were independently associated with poor functional recovery at 1- to 6-month follow-up evaluations. Seizures/epileptiform EEG findings had a strong association with lower GCS scores after surgery (p = 0.01), and they were more common in patients who underwent evacuation by craniotomy (p = 0.02). Conclusions Epileptic complications are common after acute SDH evacuation, and should be suspected in patients with an unanticipated depressed level of consciousness after surgery. Seizures worsen early functional outcome, but delayed favorable recovery is possible. Therefore, one should be cautious when discussing prognosis in the early postoperative period of patients with epileptic complications.

Rationale : Induced pluripotent stem cells (iPS) allow derivation of pluripotent progenitors from somatic sources. Originally, iPS were induced by a stemness-related gene set that included the c-MYC oncogene. Objective : Here, we determined from embryo to adult the cardiogenic proficiency of iPS programmed without c-MYC, a cardiogenicity-associated transcription factor. Methods and Results : Transgenic expression of 3 human stemness factors SOX2, OCT4, and KLF4 here reset murine fibroblasts to the pluripotent ground state. Transduction without c-MYC reversed cellular ultrastructure into a primitive archetype and induced stem cell markers generating 3-germ layers, all qualifiers of acquired pluripotency. Three-factor induced iPS (3F-iPS) clones reproducibly demonstrated cardiac differentiation properties characterized by vigorous beating activity of embryoid bodies and robust expression of cardiac Mef2c, α-actinin, connexin43, MLC2a, and troponin I. In vitro isolated iPS-derived cardiomyocytes demonstrated functional excitation-contraction coupling. Chimerism with 3F-iPS derived by morula-stage diploid aggregation was sustained during prenatal heart organogenesis and contributed in vivo to normal cardiac structure and overall performance in adult tumor-free offspring. Conclusions : Thus, 3F-iPS bioengineered without c-MYC achieve highest stringency criteria for bona fide cardiogenesis enabling reprogrammed fibroblasts to yield de novo heart tissue compatible with native counterpart throughout embryological development and into adulthood.