ABSTRACT
Pathological vascular smooth muscle cell (VSMC) behavior after vascular interventions such as angioplasty or bypass is initiated within the 3D environment of the vessel media. Here VSMCs proliferate, invade the surrounding matrix, migrate adluminally, and deposit substantial amounts of matrix, leading to myointimal hyperplasia and decreased blood flow to critical organs and tissue. Since focal adhesion kinase (FAK) mediates many of the VSMC responses to these pathologic events, it provides a reasonable pharmacologic target to limit this invasive VSMC behavior and to better understand the cellular pathophysiology of this disease. Here we quantified the effectiveness of disabling FAK in VSMCs with its dominant-negative inhibitor, FAK-related nonkinase (FRNK), in a clinically relevant 3D assay. We found that FRNK overexpression decreased VSMC invasion (both the length and frequency) in this matrix. These effects were demonstrated in the presence and absence of chemical mitotic inhibition, suggesting that FAK's effect on cellular matrix invasion, migration, and proliferation utilize separate and/or redundant signaling cascades. Mechanistically, FAK inhibition decreased its localization to focal adhesions which led to a significant decrease in FAK autophosphorylation and the phosphorylation of the serine/threonine kinase, AKT. Together these findings suggest that disruption of FAK signaling may provide a pharmaceutical tool that limits pathological VSMC cell behavior.
Subject(s)
Fibrin/chemistry , Gene Expression Regulation/physiology , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/metabolism , Protein-Tyrosine Kinases/metabolism , Actins/metabolism , Animals , Carotid Arteries/cytology , Cell Culture Techniques , Coculture Techniques , Culture Media , Dogs , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Myocytes, Smooth Muscle/cytology , Phosphorylation , Protein-Tyrosine Kinases/genetics , Proto-Oncogene Proteins c-akt/metabolismABSTRACT
Blood stream infection (BSI) is a serious complication of hematopoietic stem cell transplantation (HSCT). The aim of this retrospective cohort analysis was to describe BSI after HSCT, and to assess the predictors and outcomes of BSI after HSCT using multivariable modeling. Of the 243 subjects transplanted, 56% received allogeneic HSCT and 106 (43.6%) developed BSI. Of the 185 isolates, 68% were Gram-positive cocci, 21% were Gram-negative bacilli (GNR) and 11% were fungi. Type of allogeneic HSCT was an independent risk factor for BSI (hazard ratio (HR) 3.26, 95% confidence interval (CI) 1.50, 7.07, P = 0.01), as was the degree of HLA matching (HR 1.84, 95% CI 1.00, 3.37, P = 0.05). BSI was a significant independent predictor of mortality after HSCT (HR 1.79, 95% CI 1.18, 2.73, P = 0.007), after adjusting for acute graft-versus-host disease (GVHD) and allogeneic HSCT (both predicting death < or = 3 months after HSCT). In contrast to the effects of acute GVHD and allogeneic HSCT, the effect of BSI was evident throughout the post-HSCT period. GNR BSI and vancomycin-resistant enterococcal BSI also were significantly associated with death. We concluded that BSI is a common complication of HSCT associated with increased mortality throughout the post-HSCT period.
