In Silico Investigations of Chemical Constituents of Clerodendrum colebrookianum in the Anti-Hypertensive Drug Targets: ROCK, ACE, and PDE5.

Understanding the molecular mode of action of natural product is a key step for developing drugs from them. In this regard, this study is aimed to understand the molecular-level interactions of chemical constituents of Clerodendrum colebrookianum Walp., with anti-hypertensive drug targets using computational approaches.

An epidermis-specific chitin synthase CDNA in Choristoneura fumiferana: cloning, characterization, developmental and hormonal-regulated expression.

Chitin synthase catalyzes chitin synthesis in the exoskeleton, tracheal system and gut during insect development. A chitin synthase 1 (CfCHS1) cDNA was identified and cloned from the spruce budworm, Choristoneura fumiferana. The CfCHS1 cDNA is 5,300 bp in length and codes a 1,564-amino acid protein with a molecular mass of 178 kDa.

Role of ERK/mTOR signaling in TGFbeta-modulated focal adhesion kinase mRNA stability and protein synthesis in cultured rat IEC-6 intestinal epithelial cells.

Increasing evidence is available showing the importance of the FAK (focal adhesion kinase) protein level in the migration and homeostasis of intestinal cells. TGFbeta (transforming growth factor beta) modulates FAK protein expression in a complex fashion not only by inducing the activation of p38 and Smad signaling resulting in increased fak promoter activity and increased FAK protein levels, but also by activating ERK (extracellular signal regulated kinases), p38, and the Smad pathway. We show that the blockade of ERK signaling by a specific MEK (MAPK kinase) inhibitor attenuates TGFbeta-induced FAK mRNA stability and reduces FAK protein levels in rat IEC-6 intestinal epithelial cells.

TGF-beta1 modulates focal adhesion kinase expression in rat intestinal epithelial IEC-6 cells via stimulatory and inhibitory Smad binding elements.

TGF-beta and FAK modulate cell migration, differentiation, proliferation and apoptosis, and TGF-beta promotes FAK transcription in intestinal epithelial cells via Smad-dependent and independent pathways. We utilized a 1320 bp FAK promoter-luciferase construct to characterize basal and TGF-beta-mediated FAK gene transcription in IEC-6 cells. Inhibiting JNK or Akt negated TGF-beta-stimulated promoter activity; ERK inhibition did not block the TGF-beta effect but increased basal activity.

DOCK5 and DOCK1 regulate Caco-2 intestinal epithelial cell spreading and migration on collagen IV.

We observed previously that combined small interfering RNAs (siRNAs) targeting CrkII and CrkL, known activators of guanine nucleotide exchange factor DOCK1, strongly inhibit Caco-2 intestinal epithelial cell spreading and migration on collagen IV. DOCK1 siRNA reduced its expression >95% in Caco-2 cells but inhibited spreading much less than combined CrkII/CrkL siRNAs, suggesting that CrkII/CrkL interact with additional DOCK proteins. siRNA targeting DOCK5, a closely related DOCK1 family member, inhibited Caco-2 spreading similarly to DOCK1 siRNA, and the combined siRNAs synergistically inhibited spreading.

Transforming growth factor-beta stimulates intestinal epithelial focal adhesion kinase synthesis via Smad- and p38-dependent mechanisms.

Focal adhesion kinase (FAK) regulates cell migration, proliferation, and apoptosis. FAK protein is reduced at the edge of migrating gut epithelial sheets in vitro, but it has not been characterized in restitutive gut mucosa in vivo. Here we show that FAK and activated phospho-FAK (FAK(397)) immunoreactivity was lower in epithelial cells immediately adjacent to human gastric and colonic ulcers in vivo, but dramatically increased in epithelia near the ulcers, possibly reflecting stimulation by growth factors absent in vitro.