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Simonelli S.,University of Milan | Tinti C.,Toscana Life science Foundation | Salvini L.,Toscana Life science Foundation | Tinti L.,Toscana Life science Foundation | And 7 more authors.
Biologicals | Year: 2013

Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. Mutations in the LCAT gene leads to two rare disorders, familial LCAT deficiency and fish-eye disease, both characterized by severe hypoalphalipoproteinemia associated with several lipoprotein abnormalities. No specific treatment is presently available for genetic LCAT deficiency. In the present study, recombinant human LCAT was expressed and tested for its ability to correct the lipoprotein profile in LCAT deficient plasma. The results show that rhLCAT efficiently reduces the amount of unesterified cholesterol (-30%) and promotes the production of plasma cholesteryl esters (+210%) in LCAT deficient plasma. rhLCAT induces a marked increase in HDL-C levels (+89%) and induces the maturation of small preβ-HDL into alpha-migrating particles. Moreover, the abnormal phospholipid-rich particles migrating in the LDL region were converted in normally sized LDL. © 2013 The International Alliance for Biological Standardization.


Laschi M.,University of Siena | Tinti L.,Toscana Life science Foundation | Braconi D.,University of Siena | Millucci L.,University of Siena | And 6 more authors.
Journal of Cellular Physiology | Year: 2012

Alkaptonuria (AKU) results from defective homogentisate1,2-dioxygenase (HGD), causing degenerative arthropathy. The deposition of ochronotic pigment in joints is so far attributed to homogentisic acid produced by the liver, circulating in the blood and accumulating locally. Human normal and AKU osteoarticular cells were tested for HGD gene expression by RT-PCR, mono- and 2D-Western blotting. HGD gene expression was revealed in chondrocytes, synoviocytes, osteoblasts. Furthermore, HGD expression was confirmed by Western blotting, that also revealed the presence of five enzymatic molecular species. Our findings indicate that AKU osteoarticular cells produce the ochronotic pigment in loco and this may strongly contribute to induction of ochronotic arthropathy. © 2011 Wiley Periodicals, Inc.


Causeret F.,University Paris Diderot | Ensini M.,University Paris Diderot | Ensini M.,Toscana Life science Foundation | Teissier A.,University Paris Diderot | And 4 more authors.
PLoS ONE | Year: 2011

Development of the vertebrate forebrain and craniofacial structures are intimately linked processes, the coordinated growth of these tissues being required to ensure normal head formation. In this study, we identify five small subsets of progenitors expressing the transcription factor dbx1 in the cephalic region of developing mouse embryos at E8.5. Using genetic tracing we show that dbx1-expressing cells and their progeny have a modest contribution to the forebrain and face tissues. However, their genetic ablation triggers extensive and non cell-autonomous apoptosis as well as a decrease in proliferation in surrounding tissues, resulting in the progressive loss of most of the forebrain and frontonasal structures. Targeted ablation of the different subsets reveals that the very first dbx1-expressing progenitors are critically required for the survival of anterior neural tissues, the production and/or migration of cephalic neural crest cells and, ultimately, forebrain formation. In addition, we find that the other subsets, generated at slightly later stages, each play a specific function during head development and that their coordinated activity is required for accurate craniofacial morphogenesis. Our results demonstrate that dbx1-expressing cells have a unique function during head development, notably by controlling cell survival in a non cell-autonomous manner. © 2011 Causeret et al.


Marchetti P.,University of Pisa | Lupi R.,Azienda Ospedaliera Universitaria Pisana | Bugliani M.,University of Pisa | Kirkpatrick C.L.,University of Geneva | And 13 more authors.
Diabetologia | Year: 2012

Aims/hypothesis Glucagon-like peptide 1 (GLP-1) is a major incretin, mainly produced by the intestinal L cells, with beneficial actions on pancreatic beta cells.However,while in vivo only very small amounts of GLP-1 reach the pancreas in bioactive form, some observations indicate that GLP-1 may also be produced in the islets. We performed comprehensive morphological, functional and molecular studies to evaluate the presence and various features of a local GLP-1 system in human pancreatic islet cells, including those from type 2 diabetic patients. Methods The presence of insulin, glucagon, GLP-1, proconvertase (PC) 1/3 and PC2 was determined in human pancreas by immunohistochemistry with confocal microscopy. Islets were isolated from non-diabetic and type 2 diabetic donors. GLP-1 protein abundance was evaluated by immunoblotting and matrix-assisted laser desorption-ionisation-time of flight (MALDI-TOF) mass spectrometry. Single alpha and beta cell suspensions were obtained by enzymatic dissociation and FACS sorting. Glucagon and GLP-1 release were measured in response to nutrients.Results Confocal microscopy showed the presence of GLP-1- like and PC1/3 immunoreactivity in subsets of alpha cells, whereas GLP-1 was not observed in beta cells. The presence of GLP-1 in isolated islets was confirmed by immunoblotting, followed by mass spectrometry. Isolated islets and alpha (but not beta) cell fractions released GLP-1, which was regulated by glucose and arginine. PC1/3 (also known as PCSK1) gene expression was shown in alpha cells. GLP-1 release was significantly higher from type 2 diabetic than from nondiabetic isolated islets. Conclusions/interpretation We have shown the presence of a functionally competent GLP-1 system in human pancreatic islets, which resides in alpha cells and might be modulated by type 2 diabetes. © Springer-Verlag 2012.


Bellani L.M.,University of Siena | Salvini L.,University of Siena | Salvini L.,Toscana Life science Foundation | Dell'Aquila A.,CNR Institute of Neuroscience | Scialabba A.,University of Palermo
Acta Physiologiae Plantarum | Year: 2012

Seeds of Raphanus sativus L. subjected to accelerated ageing were investigated for reactive oxygen species (ROS) release and for content of vitamin E (tocopherol, TOC, and tocotrienol, TOC-3), fatty acids and phytosterols in seed coats, cotyledons and embryonic axes during germination. In unaged seeds, ROS release occurred mainly in seed coats of non-imbibed seeds and in seedlings (48 h of imbibition). TOC and TOC-3 were mainly represented by the γ-isoform, abundant in embryonic axes. Fatty acids were mainly found in cotyledons. In seed coat and embryonic axis, phytosterols consisted mainly of sitosterols. The effects of ageing were mainly visible in embryonic axes at 48 h of imbibition. Deterioration was associated with a decrease in fresh weight increase percentage, germination percentage, α-TOC and total fatty acid content. An increase in ROS release from seed coats and in γ-TOC, δ-TOC, γ-TOC-3 content in embryonic axis was also observed. The use of γ-TOC and total fatty acids in embryonic axis as parameters of seed quality evaluation during storage was suggested. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

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