In vivo imaging techniques: a new era for histochemical analysis

In vivo imaging techniques can be integrated with classical histochemistry to create an actual histochemistry of water. In particular, Magnetic Resonance Imaging (MRI), an imaging technique primarily used as diagnostic tool in clinical/preclinical research, has excellent anatomical resolution, unlimited penetration depth and intrinsic soft tissue contrast. Thanks to the technological development, MRI is not only capable to provide morphological information but also and more interestingly functional, biophysical and molecular. In this paper we describe the main features of several advanced imaging techniques, such as MRI microscopy, Magnetic Resonance Spectroscopy, functional MRI, Diffusion Tensor Imaging and MRI with contrast agent as a useful support to classical histochemistry

Umbilical cord mesenchymal stem cells modulate dextran sulphate sodium induced acute colitis in immunodeficient mice.

Inflammatory bowel diseases (IBD) are complex multi-factorial diseases with increasing incidence worldwide but their treatment is far from satisfactory. Unconventional strategies have consequently been investigated, proposing the use of stem cells as an effective alternative approach to IBD. In the present study we examined the protective potential of exogenously administered human umbilical cord derived mesenchymal stem cells (UCMSCs) against Dextran Sulphate Sodium (DSS) induced acute colitis in immunodeficient NOD.CB17-Prkdc scid/J mice with particular attention to endoplasmic reticulum (ER) stress. METHODS: UCMSCs were injected in NOD.CB17-Prkdc scid/J via the tail vein at day 1 and 4 after DSS administration. To verify attenuation of DSS induced damage by UCMSCs, Disease Activity Index (DAI) and body weight changes was monitored daily. Moreover, colon length, histological changes, myeloperoxidase and catalase activities, metalloproteinase (MMP) 2 and 9 expression and endoplasmic reticulum (ER) stress related proteins were evaluated on day 7. RESULTS: UCMSCs administration to immunodeficient NOD.CB17-Prkdc scid/J mice after DSS damage significantly reduced DAI (1.45\u2009\ub1\u20090.16 vs 2.08\u2009\ub1\u20090.18, p\u20093-fold), which were significantly reduced in mice receiving UCMSCs. Moreover, positive modulation in ER stress related proteins was observed after UCMSC administration. CONCLUSIONS: Our results demonstrated that UCMSCs are able to prevent DSS-induced colitis in immunodeficient mice. Using these mice we demonstrated that our UCMSCs have a direct preventive effect other than the T-cell immunomodulatory properties which are already known. Moreover we demonstrated a key function of MMPs and ER stress in the establishment of colitis suggesting them to be potential therapeutic targets in IBD treatment

Biological behavior of endothelial cells on Human Elastin-like Polypeptide-based biomaterials

Bioinspired artificial proteins modelled on tropoelastin represent an attractive tool for many biotechnological and biomedical applications. In this work, a recombinant Human Elastin-like Polypeptide (HELP) comprising the most regularly repeated hexapeptidic motif of human tropoelastin, has been employed to prepare HELP-based or \u2013coated biomaterials. In vitro characterization of the polypeptide based materials was aimed to evaluate their potential application for blood vessel reconstruction

Growth, morphology, morphometry and keratin patterns of bovine corneal epithelial cells cultured in vitro

In this study, the effects of different culture systems on bovine corneal epithelial cells were analysed in order to better understand the influence of bovine keratocytes on epithelial cells. Growth, morphological, morphometrical analyses of cells and keratin patterns were evaluated. The aim was to improve the culture technique in order to obtain a good in vitro proliferation of these cells for their employment in clinical and toxicological situations. The bovine corneal epithelial cells were cultured under different conditions: on keratocyte or 3T3-J2 fibroblast feeder layers, with media conditioned either by the two feeder layers or with a basal medium. The epithelial cells cultured on a keratocyte feeder layer as compared to those grown under the other conditions, proved to have a higher growth rate as well as to be smaller in the cytoplasmic and nuclear area; moreover, after 21 days of culture they expressed 64-kDa keratin, designed as a marker for corneal epithelial cell differentiation. To sum up, the keratocyte feeder layer is the most effective for stimulating the growth and differentiation of corneal epithelial cells, resembling the in vivo situation. It might also be successfully employed for clinical and toxicological purposes

Prostaglandin F2 alpha can modulate the growth and the differentiation of bovine corneal epithelial cells cultured in vitro

The effects of PGF2 alpha on the growth, morphology, morphometry and keratinization pattern of bovine corneal epithelial cells cultured in vitro were studied. The cells were grown with a basal medium or, in the presence of keratocytes and/or their products, using a keratocyte-conditioning medium. Cell growth was evaluated by MTT assay. Daily treatments with exogenous PGF2 alpha at concentrations equal to or lower than 10(-6) M induced significant increases in cell proliferation when the epithelial cells were cultured on a keratocyte feeder-layer or with the conditioning medium. No variations were observed in cultures grown with the basal medium. 10(-5) M PGF2 alpha induced a decrease in cell growth under all culturing conditions. PGF2 alpha did not affect cell morphology and modified only nuclear dimensions among the cells grown under different culturing conditions. No variations of any parameters were observed between cells cultured on feeder-layer, with conditioning or basal medium and the corresponding cultures supplemented with the autacoid. Moreover, PGF2 alpha induced only the disappearance of 43 kDa keratin in cells grown on basal medium, while the keratin pattern of epithelial cells cultured on feeder-layer or with the conditioning medium was not modified by the autacoid. From these data we can suppose that a cooperation could exist between PGF2 alpha and fibroblasts and their products for the modulation of cell growth. Finally, it was observed that the autacoid had no effect on cell morphology and morphometry, except for nuclear dimensions, despite the presence of other prostaglandins, such as PGE2

Relationship between the proliferation of Keratinocytes cultured in vitro and prostaglandin E2

In the growth of keratinocytes "in vitro", PGE2 seems to play an important role. We have shown that in fibroblast-keratinocyte co-cultures, indomethacin, employed at concentrations which inhibit the PGE2 synthesis, reduced the proliferation of epidermal cells. This effect was reversed by an exogenous PGE2 addition to the culture media. To better understand the relationship between keratinocytes and the autacoid, we have tested PGE2 at various concentrations in different cultural conditions, that is, epidermal cells were grown on a 3T3-J2 feeder layer, without fibroblasts and with a 3T3-J2 conditioned medium. We observed an increase in keratinocyte proliferation induced by the autacoid alone in the presence of fibroblasts, while a severe inhibitory effect was relieved when dermal cells or the conditioning medium were absent. The lack of fibroblasts and their products in the culture medium modified the morphology of keratinocytes cultured in vitro. PGE2 induced significant morphological and morphometrical variations only if added to the conditioning medium. The autacoid decreased the expression of 66 kDa protein, if cells were grown in the presence of fibroblasts or with conditioning medium, whereas it completely inhibited this keratin and those of 60, 54 kDa if cells were cultured only with a basal medium. From morphometrical and electrophoretical data we can suppose that PGE2 inhibits cell differentiation. Thus PGE2 action on keratinocytes seems to be strictly related to the presence of dermal cells

In vitro evaluation of poly[bis(ethyl alanato)phosphazene] as a scaffold for bone tissue engineering.

Polyphosphazenes with amino acid ester as side groups are biocompatible polymers that could provide valid scaffolds for cell growth. In the present study we investigate the adhesion and growth of osteoblasts obtained from rat bone marrow on matrices composed of thin fibers of poly[bis(ethyl alanato) phosphazene] (PAlaP), poly(d,l-lactic acid) (PDLLA), or PAlaP/PDLLA blend. Our data show that scaffolds of PAlaP or PAlaP/PDLLA blend enhanced the cell adhesion and growth in comparison with that observed in cultures seeded on polystyrene tissue culture plates. Although collagenase-digestible protein synthesis remained unchanged, all scaffolds induced a decrease in alkaline phosphatase activity, suggesting that osteoblasts are in the proliferation phase. Both PAlaP and PAlaP blended with PDLLA may represent a new and interesting substrate for bone tissue engineerin

Production of epidermal growth factor in human hypertrophic prostate cells cultured in vitro

The Epidermal Growth Factor (EGF) plays an important role in the regulation of in vitro growth of prostate cells inducing a strong mitogenic effect. Nevertheless in our previous study we observed that the treatment of human hypertrophic prostate cell line U285 with exogenous EGF produces a restricted effect on the cellular growth rate. This phenomenon could be due to the capacity of the cells to produce EGF. In this study we aimed to verify this hypothesis by evaluating the presence of mRNA of EGF and EGF receptor (EGF-R) and of their translation products in U285 cells, before and after the treatment with suramin and exogenous EGF. Moreover we studied the effects exerted by these substances on the proliferative rate of the cells U285 after different treatment protocols. The presence in the cells of mRNA for EGF and EGF-R and of their translation products was demonstrated by means of reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemical methods respectively. The modification of growth rate induced by these drugs was studied by FRAME Cytotoxicity Test. The operative modalities adopted to carry out these growth assays tended to 1) focus the effects of suramin in relation to in vitro cellular growth phase; 2) verify the reversibility of its effects; 3) ascertain if it was possible to antagonize the action of suramin by adding exogenous EGF. The results obtained from the RT-PCR showed the presence, in the control cells and in the treated ones, of mRNA coding for EGF and EGF-R. The immunocytochemical analysis indicated that 20% of the control cells are EGF positive, and 83% are EGF-R positive, confirming the results obtained with RT-PCR. Moreover, these stainings showed that the treatment with EGF does not significantly modify the percentage of cells marked by the anti-EGF antibody, while treatments with suramin and suramin plus EGF double this percentage. None of the treatments modifies the percentage of EGFR positive cells. The growth assays showed that the exposition to highest doses of suramin in the first 24 h of cultures causes a decrease (p<0.05) of the cellular proliferation during the following 48 h and 72 h and that these effects are irreversible. Moreover, a contemporaneous exposition of the cells to EGF and suramin at seeding strengthens the cytotoxic action of the last drug. To sum up, the demonstration of the presence in the U285 cells of mRNA coding for EGF and EGF-R and of the corresponding proteins, confirms the hypothesis that these cells can produce EGF. Moreover, the cytotoxicity experiments allowed a focusing of the role of the endogenous EGF in the regulation of the U285 cells proliferation and confirmed the importance of biological events that take place in U285 cells during the first 24 h of culture