TNFalpha blockade prevents the development of inflammatory bowel disease in HLA-B27 transgenic rats.

Abstract Rats transgenic for HLA-B27 and human beta2microglobulin (B27TR) develop a multi-systemic disease resembling inflammatory bowel disease (IBD) and spondyloarthritis. TNFalpha has a crucial role in chronic inflammation. Our objective was to evaluate the effect of anti-TNFalpha treatment on spontaneous IBD in B27TR. Nine-week-old B27TR received monoclonal anti-TNFalpha or an isotypic IgG2a,k up to age of 18 weeks. A second group was monitored up to 18 weeks and then randomly assigned to anti-TNFalpha or IgG2 a,k treatment. Each rat was monitored for clinical IBD manifestations. After sacrifice, the colon was examined for pathological changes. TNFalpha receptors (TNF-R1, TNF-R2), Fas/Fas-L expression and apoptosis were evaluated. IgG2a,k-treated and untreated B27TR presented signs of IBD at 11 weeks, whereas in anti-TNFalpha-treated B27TR no IBD signs were detected. In the late treatment, IBD signs improved after 1 week. Histopathological analysis of IgG2a,k-treated B27TR colon showed inflammatory signs that were widely prevented by early anti-TNFalpha treatment. Late treatment did not significantly reduce inflammation. TNF-R1 was weakly expressed in intestinal epithelial cells of IgG2a,k-treated B27TR, while it was comparable to controls in anti-TNFalpha-treated animals. TNF-R2 immunopositivity was strongly evident in IgG2a,k-treated B27TR, whereas was absent in anti-TNFalpha-treated rats. RT-PCR confirmed these results. IgG2a,k-treated B27TR showed, at 18 weeks, few Fas-positive cells and an increase of Fas-L-positive cells. At 27 weeks, Fas-/Fas-L-positive cell number was significantly low. Anti-TNFalpha treatment increased Fas-L expression, whereas Fas increased only with the early treatment. TNFalpha blockade is effective in preventing inflammation in early phase of IBD, maintaining the homeostatic balance of apoptosis.

Neodymium:yttrium aluminum garnet laser irradiation with low pulse energy: a potential tool for the treatment of peri-implant disease.

Bacterial contamination may seriously compromise successful implant osteointegration in the clinical practice of dental implantology. Several methods for eliminating bacteria from the infected implants have been proposed, but none of them have been shown to be an effective tool in the treatment of peri-implantitis. In the present study, we investigated the efficacy of pulsed neodymium:yttrium aluminum garnet laser irradiation (Nd:YAG) in achieving bacterial ablation while preserving the surface properties of titanium implants. For this purpose, suspensions of Escherichia coli or Actinobacillus (Haemophilus) actinomycetemcomitans were irradiated with different laser parameters, both streaked on titanium implants, and in broth medium. It was found, by light and atomic force microscopy, that Nd:YAG laser, when used with proper working parameters, was able to bring about a consistent microbial ablation of both aerobic and anaerobic species, without damaging the titanium surface.

Morphofunctional integration between skeletal myoblasts and adult cardiomyocytes in coculture is favored by direct cell-cell contacts and relaxin treatment.

The success of cellular cardiomyoplasty, a novel therapy for the repair of postischemic myocardium, depends on the anatomical integration of the engrafted cells with the resident cardiomyocytes. Our aim was to investigate the interaction between undifferentiated mouse skeletal myoblasts (C2C12 cells) and adult rat ventricular cardiomyocytes in an in vitro coculture model. Connexin43 (Cx43) expression, Lucifer yellow microinjection, Ca2+ transient propagation, and electrophysiological analysis demonstrated that myoblasts and cardiomyocytes were coupled by functional gap junctions. We also showed that cardiomyocytes upregulated gap junctional communication and expression of Cx43 in myoblasts. This effect required direct cell-to-cell contact between the two cell types and was potentiated by treatment with relaxin, a cardiotropic hormone with potential effects on cardiac development. Analysis of the gating properties of gap junctions by dual cell patch clamping showed that the copresence of cardiomyocytes in the cultures significantly increased the transjunctional current and conductance between myoblasts. Relaxin enhanced this effect in both the myoblast-myoblast and myoblast-cardiomyocyte cell pairs, likely acting not only on gap junction formation but also on the electrical properties of the preexisting channels. Our findings suggest that myoblasts and cardiomyocytes interact actively through gap junctions and that relaxin potentiates the intercellular coupling. A potential role for gap junctional communication in favoring the intercellular exchange of regulatory molecules, including Ca2+, in the modulation of myoblast differentiation is discussed.