Palmitic acid and eicosapentaenoic acid supplementation in 3T3 adipocytes: impact on lipid storage and oxidative stress.

Objectives: Obesity is a worldwide public health problem, predisposing individuals to serious cardiovascular and metabolic complications such as type 2 diabetes mellitus. White adipose tissue serves as an important regulator of energy balance, and its expansion in obesity can trigger inflammatory reactions and oxidative stress, which can also lead to insulin resistance. Adipocytes, with a key role in regulating metabolic homeostasis, respond to increased calorie intake and altered fatty acid composition with hypertrophy or hyperplasia.

Biphasic reinforcement of nascent adhesions by vinculin.

Vinculin is an integral component of integrin adhesions, where it functions as a molecular clutch coupling intracellular contraction to the extracellular matrix. Quantitating its contribution to the reinforcement of newly forming adhesions, however, requires ultrasensitive cell force assays covering short time and low force ranges. Here, we have combined atomic force microscopy-based single-cell force spectroscopy (SCFS) and optical tweezers force spectroscopy to investigate the role of vinculin in reinforcement of individual nascent adhesions during the first 5 min of cell contact with fibronectin or vitronectin.

E-cadherin integrates mechanotransduction and EGFR signaling to control junctional tissue polarization and tight junction positioning.

Generation of a barrier in multi-layered epithelia like the epidermis requires restricted positioning of functional tight junctions (TJ) to the most suprabasal viable layer. This positioning necessitates tissue-level polarization of junctions and the cytoskeleton through unknown mechanisms. Using quantitative whole-mount imaging, genetic ablation, and traction force microscopy and atomic force microscopy, we find that ubiquitously localized E-cadherin coordinates tissue polarization of tension-bearing adherens junction (AJ) and F-actin organization to allow formation of an apical TJ network only in the uppermost viable layer.

The vinculin-DeltaIn20/21 mouse: characteristics of a constitutive, actin-binding deficient splice variant of vinculin.

Background: The cytoskeletal adaptor protein vinculin plays a fundamental role in cell contact regulation and affects central aspects of cell motility, which are essential to both embryonal development and tissue homeostasis. Functional regulation of this evolutionarily conserved and ubiquitously expressed protein is dominated by a high-affinity, autoinhibitory head-to-tail interaction that spatially restricts ligand interactions to cell adhesion sites and, furthermore, limits the residency time of vinculin at these sites. To date, no mutants of the vinculin protein have been characterized in animal models.

Vinculin facilitates cell invasion into three-dimensional collagen matrices.

The cytoskeletal protein vinculin contributes to the mechanical link of the contractile actomyosin cytoskeleton to the extracellular matrix (ECM) through integrin receptors. In addition, vinculin modulates the dynamics of cell adhesions and is associated with decreased cell motility on two-dimensional ECM substrates. The effect of vinculin on cell invasion through dense three-dimensional ECM gels is unknown.

The effects of dopamine receptor agonists and antagonists on the secretory rate of cockroach (Periplaneta americana) salivary glands.

The acinar salivary glands of the cockroach, Periplaneta americana, are innervated by dopaminergic and serotonergic nerve fibers. Serotonin stimulates the secretion of protein-rich saliva, whereas dopamine causes the production of protein-free saliva. This suggests that dopamine acts selectively on ion-transporting peripheral cells within the acini and the duct cells, and that serotonin acts on the protein-producing central cells of the acini.