All these morphologic and functional features are consistent with those described for brain Mato cells. Thus, this study showed the presence of autofluorescent perivascular macrophages, different from microglia, with a scavenger function that may contribute to the maintenance of the blood-retinal barrier in healthy conditions and that are also involved in retinopathy.

Aims/hypothesis Suppressor of cytokine signalling (SOCS) proteins are powerful inhibitors of pathways involved in survival and function of pancreatic beta cells. Whereas SOCS1 and SOCS3 have been involved in immune and inflammatory processes, respectively, in beta cells, nothing is known about SOCS2 implication in the pancreas. Methods Transgenic (tg) mice were generated that constitutively produced SOCS2 in beta cells (βSOCS2) to define whether this protein is implicated in beta cell functioning and/or survival.Results Constitutive production of SOCS2 in beta cells leads to hyperglycaemia and glucose intolerance. This phenotype is not a consequence of decreased beta cell mass or inhibition of insulin synthesis. However, insulin secretion to various secretagogues is profoundly altered in intact animals and isolated islets. Interestingly, constitutive SOCS2 production dampens the rise in cytosolic free calcium concentration induced by glucose, while glucose metabolism is unchanged. Moreover, tg islets have a depletion in endoplasmic reticulum Ca 2+ stores, suggesting that SOCS2 interferes with calcium fluxes. Finally, inElectronic supplementary material The online version of this article

The periphery of the vitreous body contains a population of cells termed hyalocytes. Despite the existence for more than one century of publications devoted to the pecten oculi, a convoluted coil of blood vessels that seems to be the primary source of nutrients for the avian avascular retina, little information can be found concerning the pecteneal hyalocytes. These cells are situated on the inner limiting membrane in close relationship with the convolute blood vessels. To characterize the origin and macrophagic activity of pecteneal hyalocytes, we have analysed two different stages of quail eye development using histochemistry and immunohistochemistry. Pecteneal hyalocytes express the QH1 epitope and cKit, confirming that these cells belong to the haematopoietic system. They also express vimentin, an intermediate filament protein present in cells of mesenchymal origin and very important for differentiation of fully active macrophages. However, similarly as described in porcine hyalocytes, pecteneal hyalocytes express the glial fibrillary acidic protein, a recognized neuroglial marker. Pecteneal hyalocytes did not express other neuroglial markers, such as glutamine synthetase or S100. Acidic phosphatase was activated and Lep100 was found in secondary lysosomes, confirming phagocytic activity of pecteneal hyalocytes during ocular development. Pecteneal hyalocytes strongly react with RCA-I, WFA, WGA, PNA, SNA, LEA and SBA lectins, whereas other avian macrophages from thymus and the bursa of Fabricius did not bind PNA, SNA and LEA lectins. Interestingly, WGA lectin reacts with all kinds of avian macrophages, including pecteneal hyalocytes, probably reflecting the specific binding of WGA to components of the phagocytic and endocytic pathways. In conclusion, pecteneal hyalocytes are a special subtype of blood-borne macrophages that express markers not specifically associated with the haematopoietic system.

Loss of renal function during normal aging is associated with vascular alterations. Consequently, new therapeutic approaches, including gene therapy, to protect renal endothelial cells are expected to be greatly beneficial. Quail mesonephros is a transitory embryonic kidney that has been used for the study of vascular development and involution. Vascular alterations in regressing mesonephros are similar to those observed in aging kidney. In the present study, we examined adenovirus-mediated gene transfer to endothelial cells in primary cultures from developing and regressing quail mesonephros. Quail embryos with developing and regressing mesonephros were examined on day 6 (30HH) and day 11 (40HH) of incubation, respectively. The senescence markers, associated β-galactosidase activity and p16^INK4a, were examined in whole mesonephros. Quail embryos were injected intracardiacally with adenoviral vectors (rAd-CMV-LacZ) and endothelial cell transduction examined. In addition, primary cell cultures from mesonephros were exposed to adenoviral vectors. Endothelial cells in primary cultures were identified as QH1(+), LEP100(–) and acidic phosphatase(–) cells and adenovirus-transduced cells were those positive for bacterial-associated β-galactosidase activity. We report that endothelial cells in the whole regressing mesonephros and primary cell cultures expressed senescence markers. In addition, we observed that adenoviral vectors were able to transduce endothelial cells in the whole regressing mesonephros, and that cultured endothelial and macrophagic cells from the regressing mesonephros were more efficiently transduced than those derived from the developing mesonephros. Our results suggest that quail mesonephros provides a practical model to assay gene transfer to endothelial cells in regressing/senescent vessels.