Cellular retinol binding protein 1 transfection reduces proliferation and AKT-related gene expression in H460 non-small lung cancer cells

Molecular Biology Reports - In recent years, new treatments with novel action mechanisms have been explored for advanced non-small cell lung cancer (NSCLC). Retinoids promote cancer cell...     

Phenotypic heterogeneity influences the behavior of rat aortic smooth muscle cells in collagen lattice

Phenotypic modulation of vascular smooth muscle cells (SMCs) in atherosclerosis and restenosis involves responses to the surrounding microenvironment. SMCs obtained by enzymatic digestion from tunica media of newborn, young adult (YA) and old rats and from the thickened intima (TI) and underlying media of young adult rat aortas 15 days after ballooning were entrapped in floating populated collagen lattice (PCL). TI-SMCs elongated but were poor at PCL contraction and remodeling and expressed less alpha2 integrin compared to other SMCs that appeared more dendritic. During early phases of PCL contraction, SMCs showed a marked decrease in the expression of alpha-smooth muscle actin and myosin. SMCs other than TI-SMCs required 7 days to re-express alpha-smooth muscle actin and myosin. Only TI-SMCs in PCL were able to divide in 48 h, with a greater proportion in S and G2-M cell cycle phases compared to other SMCs. Anti-alpha2 integrin antibody markedly inhibited contraction but not proliferation in YA-SMC-PLCs; anti-alpha1 and anti-alpha2 integrin antibodies induced a similar slight inhibition in TI-SMC-PCLs. Finally, TI-SMCs rapidly migrated from PCL on plastic reacquiring their epithelioid phenotype. Heterogeneity in proliferation and cytoskeleton as well the capacity to remodel the extracellular matrix are maintained, when SMCs are suspended in PCLs.     

Transglutaminase 2 as a biomarker of osteoarthritis: an update

Osteoarthritis is a progressive joint disease characterized by cartilage degradation and bone remodelling. Under physiologic conditions, articular cartilage displays a stable chondrocyte phenotype, whereas in osteoarthritis a chondrocyte hypertrophy develops near the sites of cartilage surface damage and associates to the pathologic expression of type X collagen. Transglutaminases (TGs) include a family of Ca²⁺-dependent enzymes that catalyze the formation of γ-glutamyl cross-links. Their substrates include a variety of intracellular and extracellular macromolecular components. TGs are ubiquitously and abundantly expressed and implicated in a variety of physiopathological processes. TGs activity is modulated by inflammatory cytokines. TG2 (also known as tissue transglutaminase) mediates the hypertrophic differentiation of joint chondrocytes and interleukin-1-induced calcification. Histomorphometrical and biomolecular investigations document increased TG2 expression in human and experimental osteoarthritis. Consequently, the level of TG2 expression may represent an adjuvant additional marker to monitor tissue remodelling occurring in osteoarthritic joint tissue. Experimental induction of osteoarthritis in TG2 knockout mice is followed from reduced cartilage destruction and increased osteophyte formation compared to wild-type mice, suggesting a different influence on joint bone and cartilage remodelling. The capacity of transamidation by TG2 to regulate activation of latent TGF-β seems to have a potential impact on the regulation of inflammatory response in osteoarthritic tissues. Additional studies are needed to define TG2-regulated pathways that are differently modulated in osteoblasts and chondrocytes during osteoarthritis.     

Alpha actin isoforms expression in human and rat adult cardiac conduction system

In the adult heart, cardiac muscle comprises the working myocardium and the conduction system (CS). The latter includes the sinoatrial node (SAN), the internodal tract or bundle (IB), the atrioventricular node (AVN), the atrioventricular bundle (AVB), the bundle branches (BB) and the peripheral Purkinje fibers (PF). Most of the information concerning the phenotypic features of CS tissue derives from the characterization of avian and rodent developing hearts; data concerning the expression of actin isoforms in adult CS cardiomyocytes are scarce. Using specific antibodies, we investigated the distribution of α-skeletal (α-SKA), α-cardiac (α-CA), α-smooth muscle (α-SMA) actin isoforms and other muscle-typical proteins in the CS of human and rat hearts at different ages. SAN and IB cardiomyocytes were characterized by the presence of α-SMA, α-CA, calponin and caldesmon, whereas α-SKA and vimentin were absent. Double immunofluorescence demonstrated the co-localisation of α-SMA and α-CA in I-bands of SAN cardiomyocytes. AVN, AVB, BB and PF cardiomyocytes were α-SMA, calponin, caldesmon and vimentin negative, and α-CA and α-SKA positive. No substantial differences in actin isoform distribution were observed in human and rat hearts, except for the presence of isolated subendocardial α-SMA positive cardiomyocytes co-expressing α-CA in the ventricular septum of the rat. Aging did not influence CS cardiomyocyte actin isoform expression profile. These findings support the concept that cardiomyocytes of SAN retain the phenotype of a developing myogenic cell throughout the entire life span.