Autoimmune-mediated vascular injury occurs prior to sustained hyperglycemia in a murine model of type I diabetes mellitus

FSP-1 Impairs the Function of Endothelium Leading to Failure of Arteriovenous Grafts in Diabetic Mice

To understand how endothelial cell (EC) dysfunction contributes to the failure of arteriovenous graft (AVG), we investigated the role of fibroblast-specific protein 1 (FSP-1) in cultured ECs and a mouse AVG model. In vitro, we uncovered a new FSP-1-dependent pathway that activates rho-associated, coiled-coil-containing protein kinase 1 (ROCK1) in ECs, leading to phosphorylation of myosin light chain 2 resulting in EC dysfunction. In cultured ECs, high glucose stimulated FSP-1 expression and increased permeability of an EC monolayer. The increase in permeability by the high glucose concentration was mediated by FSP-1 expression. Treatment of cultured ECs with FSP-1 caused leakage of the endothelial barrier plus increased expression of adhesion molecules and decreased expression of junction molecules. These responses were initiated by binding of FSP-1 to receptor for advanced glycation end products, which resulted in ROCK1 activation. In vivo, diabetes increased infiltration of inflammatory cells into AVGs and stimulated neointima formation. Increased FSP-1 expression and ROCK1 activation were found in AVGs of diabetic mice. Blocking FSP-1 suppressed diabetes-induced ROCK1 activation in AVGs. In mice with FSP-1 knockout or with ROCK1 knockout, accumulation of inflammatory cells and neointima formation in AVG were attenuated despite diabetes. Thus, mechanisms of inhibiting FSP-1 in ECs could improve AVG function.

Analysis of maternal and fetal cardiovascular systems during hyperglycemic pregnancy in the nonobese diabetic mouse

Preconception or gestationally induced diabetes increases morbidities and elevates long-term cardiovascular disease risks in women and their children. Spontaneously hyperglycemic (d)-NOD/ShiLtJ female mice, a type 1 diabetes model, develop bradycardia and hypotension after midpregnancy compared with normoglycemic, age- and gestational day (GD)-matched control (c-NOD) females. We hypothesized that onset of the placental circulation at GD 9-10 and rapid fetal growth from GD 14 correlate with aberrant hemodynamic outcomes in d-NOD females. To develop further gestational time-course correlations between maternal cardiac and renal parameters, high-frequency ultrasonography was applied to d- and c-NOD mice (virgin and at GD 8-16). Cardiac output and left ventricular (LV) mass increased in c-NOD but not in d-NOD mice. Ultrasound and postmortem histopathology showed overall greater LV dilation in d-NOD than in c-NOD mice at mid to late gestation. These changes suggest blunted remodeling and altered functional adaptation of d-NOD hearts. Umbilical cord ultrasounds revealed lower fetal heart rates from GD 12 and lower umbilical flow velocities at GD 14 and GD 16 in d-NOD versus c-NOD pregnancies. From GD 14 to GD 16, d-NOD fetal losses exceeded c-NOD fetal losses. Similar aberrant responses in pregnancies of women with diabetes may elevate postpartum maternal and child cardiovascular risk, particularly if mothers lack adequate prenatal care or have poor glycemic control during gestation.