Histamine is an important mediator in immune responses, but it is unclear whether periodontal tissues express histamine receptors and are able to respond to histamine. We hypothesized that histamine, inflammatory cytokines, and bacterial components released in inflamed periodontal tissues may be synergistically involved in periodontitis. The present study showed that human gingival fibroblasts ...

Violacein, a pigment isolated from Chromobacterium violaceum in the Amazon River, presents diverse biologic properties and attracts interest as a consequence of its antileukemic activity. Elucidation of the molecular mechanism mediating this activity will provide further relevant information for understanding its effects on the cellular physiology of untransformed cells and for considering its ...

Protease-activated receptor-1 (PAR-1) is a G-protein-linked receptor on platelets and perivascular cells activated by alpha-thrombin and the PAR-1-activating peptide, SFLLRN. alpha-Thrombin activates PAR-1 by cleaving it at R41-S42 to release the 41-residue peptide TR(1-41). Unexpectedly, platelet activation with SFLLRN was also associated with PAR-1 cleavage and the release of TR(1-41). Both P...

We and other studies have elucidated single molecules that can attenuate aging and extend longevity. Indeed, these molecules could prevent age-associated diseases simultaneously and probably extending healthy-life spans. In this review, we discuss recent advances, controversies, opportunities and challenges surrounding ursolic acid (UA) in relationship with aging. In this regard, UA also known ...

Activation of the Wnt/beta-catenin pathway promotes the development of several cancers and is an attractive target for chemopreventive and chemotherapeutic agents. Nonsteroidal antiinflammatory drugs (NSAIDs) have been reported to antagonize beta-catenin function, but their mechanism of action is not known. We demonstrate here that interference with beta-catenin function by NSAIDs does not corr...

The alpha 2 and beta 2 adrenergic receptors, both of which are activated by epinephrine, but which can be differentiated by selective drugs, have opposite effects (inhibitory and stimulatory) on the adenylyl cyclase system. The two receptors are homologous with each other, rhodopsin, and other receptors coupled to guanine nucleotide regulatory proteins and they contain seven hydrophobic domains...

The nuclear receptor retinoid X receptor-alpha (RXR-alpha)-peroxisome proliferator-activated receptor-gamma (PPAR-gamma) heterodimer was recently reported to have a crucial function in mediating the deleterious effects of organotin compounds, which are ubiquitous environmental contaminants. However, because organotins are unrelated to known RXR-alpha and PPAR-gamma ligands, the mechanism by whi...

Hepatocyte growth factor/scatter factor (HGF/SF) and macrophage stimulating protein (MSP) are plasminogen-related kringle proteins that lost serine protease domain enzymatic activity and became ligands for cell surface tyrosine kinase receptors. They are activated by cleavage to disulfide-linked alphabeta chains. Surprisingly, despite structural similarities, the high affinity receptor binding ...

IL-2 binds to high- and low-affinity receptors on activated T cells. The high-affinity receptor was hypothesized to consist of the noncovalent association between the alpha chain (IL-2-R-alpha, p55) and a beta chain (IL-2-R-beta, p70), whereas the low-affinity receptor consists of p55 without p70. We now directly identify p70 as a 65-77-kD glycoprotein doublet. Preparative quantities of the IL-...