Molecular Cloning and Characterization of Canine Pre-B-Cell Colony-Enhancing Factor

Abstract

During our previous attempt to search for the candidate genes to acute lung injury (ALI), we unexpectedly identified PBEF as the most highly upregulated gene in a canine model of ALI by crosshybridizing canine lung cRNA to the Affymetrix human gene chip HG-U133A. The result suggested that PBEF may be a potential biomarker in ALI. To extend and translate that finding, we have performed the molecular cloning and characterization of canine PBEF cDNA in this study. Deduced amino acid sequence alignment revealed that the PBEF gene is evolutionarily highly conserved, with the canine PBEF protein sequence 96% identical to human PBEF and 94% identical to both murine and rat PBEF counterparts. Canine PBEF protein was successfully expressed both by in vitro transcription coupled with translation in a cell-free system and by transfection of canine PBEF cDNA into the human lung type II alveolar adenocarcinoma cell line A549. The expressed canine PBEF protein was visualized by either an anti-V5 tag peptide polyclonal antibody or an anti-canine PBEF peptide polyclonal antibody. RT-PCR assay indicates that canine PBEF is expressed in canine lung, brain, heart, liver, spleen, kidney, pancreas, and muscle, with liver showing the highest expression,followed by muscle. Isolation of the canine PBEF cDNA and expression of its recombinant protein may provide molecular tools to study the molecular mechanism of ALI in the canine model and to elucidate the potential role of PBEF as an ALI biomarker.

Relationship Between Cerebrospinal Fluid Visfatin (PBEF/Nampt) Levels and Adiposity in Humans

“…Leptin, an adipokine that is considerably smaller than visfatin (16 vs. 52 kDa; 167 vs. 473 amino acids), crosses the blood-brain barrier (BBB) via an active, saturable transport system (17) and displays a 5-to 10-fold less pronounced CSF-to-plasma ratio than that observed for visfatin in the present experiments (18). This pattern suggests that circulating visfatin can likewise enter the brain compartment, probably also via an active transport mechanism, although it cannot be ruled out that there are central nervous secretion sites for the peptide (19). In our study, CSF visfatin levels decreased with increasing plasma visfatin levels and adiposity, supporting the assumption that visfatin transport across the BBB is impaired when circulating visfatin increases as a result of excess body fat.…”

Visfatin activates eNOS via Akt and MAP kinases and improves endothelial cell function and angiogenesis in vitro and in vivo: translational implications for atherosclerosis

“…Although the exact role of visfatin continues to be elucidated, a critical role in pathobiology is suggested by its high degree of conservation throughout evolution (4,11,12,16). Accumulating evidence suggests that visfatin exerts important dual effects as an intracellular cell cycle regulatory protein (iNampt), in addition to secreted cytokine (eNampt), capable of modulating innate immunity and inflammatory responses across various cell types.…”

Single and Concurrent Effects of Endurance and Resistance Training on Plasma Visfatin, Insulin, Glucose and Insulin Resistance of Non-Athlete Men with Obesity

“…Studies indicated that visfatin is an adipokine with insulin-like function and this effect varies depending on the amount of insulin., It has been reported that hyperglycemia causes increasing visfatin levels (42). In this regard, Haider et al (5) demonstrated that insulin injection in diabetic patients prevents increasing plasma visfatin, therefore, reduced insulin occurred after pancreatic beta cells dysfunction occurred which may be compensated for changes in visfatin concentration (43).…”