Fibroblast growth factor 9: cloning and immunolocalisation during tooth development in Didelphis albiventris.

There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.

GM-CSF and TNF-alpha synergize to increase in vitro granuloma size of PBMC from humans induced by Schistosoma mansoni recombinant 28-kDa GST.

The 28-kDa Glutathione S-transferase of Schistosoma mansoni (Sm28 GST) was described as a protective antigen capable of reducing female fecundity and the number of eggs in mice hepatic tissues. The role of GM-CSF and TNF-alpha in the in vitro granuloma reaction of peripheral blood mononuclear cells (PBMC) from chronic intestinal schistosomiasis patients before and after chemotherapy treatment to S. mansoni recombinant Sm28 GST was evaluated. Treatment of PBMC with recombinant Sm28 GST caused a significant increase in granuloma formation when compared to SEA or SWAP. Contrary to SEA or SWAP, Sm28 GST was not capable of inducing significant cellular proliferation. Moreover, recombinant Sm28 GST promoted a significant elevation in GM-CSF and TNF-alpha levels. However, we did not detect any significant IL-10 production. When Sm28 GST was applied in the presence of anti-GM-CSF or anti-TNF-alpha antibodies in cultures, we observed a significant decrease in granuloma size. Indeed, our results demonstrated that Sm28 GST was capable of promoting high in vitro granuloma index, and this event was associated with the balance of GM-CSF and TNF-alpha. These evidences suggest a role for GM-CSF as a major mediator in increasing granuloma reaction in human schistosomiasis. This event may contribute to exacerbate the pathology resulting from egg deposition in host tissues.