Mathematical modeling of the impact of actin and keratin filaments on keratinocyte cell spreading.

Keratin intermediate filaments (IFs) form cross-linked arrays to fulfill their structural support function in epithelial cells and tissues subjected to external stress. How the cross-linking of keratin IFs impacts the morphology and differentiation of keratinocytes in the epidermis and related surface epithelia remains an open question. Experimental measurements have established that keratinocyte spreading area is inversely correlated to the extent of keratin IF bundling in two-dimensional culture.

Cloning and functional analysis of the swine eNOS promoter.

We have cloned the swine eNOS promoter and analyzed its function in newborn swine pulmonary artery endothelial cells (PAECs). Analysis of the 2.1 kb 5' flanking region revealed that the swine eNOS promoter is, like its counterparts in human and other species, a TATA-less promoter.

The effect of phenotype on mechanical stretch-induced vascular smooth muscle cell apoptosis.

The present study evaluated mechanical stretch-induced apoptosis in swine vascular smooth muscle cells (VSMC) of different phenotypes. We demonstrated that differentiated VSMC express a greater level of Bcl-2-associated death factor (BAD) and have a significant cell loss when exposed to mechanical stretch (10% elongation, 1 Hz) for 24 h. We further demonstrated that apoptosis was significantly increased only in differentiated VSMC exposed to mechanical stretch.

Developmental expression of endothelin receptors in postnatal swine mesenteric artery.

Studies were conducted to determine whether endothelin (ET) ETA and ETB receptor protein and mRNA expression is developmentally regulated in the postnatal swine mesenteric circulation. To this end, Western blotting and real-time reverse PCR were performed on protein and total RNA isolated from the mesenteric artery harvested from 3-, 10-, and 30-d-old swine. Western blot analysis revealed that ETA and ETB receptor protein expression in the swine mesenteric artery decreased over the age range studied; thus, ETA and ETB receptor protein expression was significantly greater in the 3-d-old group then progressively declined over the first postnatal month.

Regulation of alpha(2)-adrenoceptors in human vascular smooth muscle cells.

This study analyzed the regulation of alpha2-adrenoceptors (alpha2-ARs) in human vascular smooth muscle cells (VSMs). Saphenous veins and dermal arterioles or VSMs cultured from them expressed high levels of alpha2-ARs (alpha2C > alpha2A, via RNase protection assay) and responded to alpha2-AR stimulation [5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (UK-14,304, 1 microM)] with constriction or calcium mobilization. In contrast, VSMs cultured from aorta did not express alpha2-ARs and neither cultured cells nor intact aorta responded to UK-14,304.

Development of the myogenic response in postnatal intestine: role of PKC.

Previous attempts to determine developmental changes in the vascular myogenic response have been confounded by the presence of competing vasoactive stimuli or the use of isolated vessels with markedly different baseline diameters. To circumvent these issues, small mesenteric arteries (diameter approximately 150 microm) from 1- and 10-day-old piglets were studied in vitro under no-flow conditions. In situ studies demonstrated that the intravascular pressure and diameter of these vessels were similar in both age groups, allowing an effective comparison of the myogenic response not obscured by differences in basal diameter.

Developmental expression of eNOS in postnatal swine mesenteric artery.

Developmental changes in the expression of endothelial nitric oxide synthase (eNOS) within the mesenteric artery of swine were studied in fetal (110 days postconception/117 days total gestation) and on postnatal days 1, 3, 10, and 30. Subjects in the 1-day-old group were subdivided into fed and nonfed. Transcription of eNOS was determined by real-time PCR, protein expression was evaluated by Western blotting, and hemodynamic and oxygenation parameters were measured within in situ gut loops before and after the administration of N(G)-monomethyl-L-arginine (L-NMMA).

Activated monocytes induce smooth muscle cell death: role of macrophage colony-stimulating factor and cell contact.

Background: Plaque disruption is the inciting event for coronary thrombosis and acute coronary syndromes. Multiple factors influence plaque rupture, including the loss of vascular smooth muscle cells (VSMCs). We hypothesized that monocytes/macrophages (MMs) activated by macrophage colony-stimulating factor (M-CSF) are responsible for VSMC death.