Chiara Pecorini

Alpha-Tocopherol Counteracts the Cytotoxicity Induced by Ochratoxin A in Primary Porcine Fibroblasts

The aims of the current study were to determine the half-lethal concentration of ochratoxin A (OTA) as well as the levels of lactate dehydrogenase release and DNA fragmentation induced by OTA in primary porcine fibroblasts, and to examine the role of α-tocopherol in counteracting its toxicity. Cells showed a dose-, time- and origin-dependent (ear vs. embryo) sensitivity to ochratoxin A. Pre-incubation for 3 h with 1 nM α-tocopherol significantly (P < 0.01) reduced OTA cytotoxicity, lactate dehydrogenase release and DNA damage in both fibroblast cultures. These findings indicate that α-tocopherol supplementation may counteract short-term OTA toxicity, supporting its defensive role in the cell membrane.

Heterologous Expression of Biologically Active Porcine Lactoferrin in Pichia Pastoris Yeast

INTRODUCTIONLactoferrin is a glycoprotein of about 80kDa, belonging to the transferrin family. It is foundin colostrum, milk and other biological fluids. This protein has antibacterial, antiviral andanticarcinogenicactivity;itisinvolvedinironabsorptionandimmunomodulationanditalsopromotes the growth of some strains of lactic acid bacteria (Brock, 2002; Kim

Evaluation of the damage induced by ochratoxin A and the protective role of α-tocopherol in cultured bovine mammary epithelial cells

Evaluation of the damage induced by ochratoxin A and the protective role of α-tocopherol in cultured bovine mammary epithelial cells E. Fusi & R. Rebucci & C. Pecorini & L. Rossi & F. D’Ambrosio & A. Baldi Published online: 7 August 2008 # Springer Science + Business Media B.V. 2008

Effect of growth factors and lactogenic hormones on expression of plasminogen activator-related genes and cell proliferation in a bovine mammary epithelial cell line.

There is conflicting evidence in the literature as to whether up-regulation of urokinase plasminogen activator (u-PA) expression is related to bovine mammary epithelial cell growth. The role of u-PA receptor (u-PAR) and that of the plasminogen activator inhibitors type 1 and type 2 (PAI-1 and PAI-2) in bovine mammary epithelial cell proliferation is not known. The effect of growth factors and various hormones known to affect mammary function on expression of u-PA, u-PAR, PAI-1, PAI-2 and cell proliferation using the BME-UV1 bovine mammary epithelial cell line was examined. Cell proliferation was measured using the MTT assay and direct cell enumeration. Results showed that both IGF-1 and EGF increased cell proliferation but EGF was a more potent mitogen than IGF-1. Furthermore, IGF-1 increased by 2-fold expression of both u-PA and u-PAR while EGF increased by 3·8-fold the expression of only u-PAR. Both growth factors had no effect on expression of PAI-1 and PAI-2. In a manner consistent with changes in gene expression, EGF and to a lesser extent IGF-1 up-regulated total cell associated, membrane-bound and secreted u-PA activity. Thus, a strong correlation exists between u-PAR gene expression along with the activity of u-PA present on cell membranes and cell proliferation. Dexamethasone, prolactin and surprisingly insulin had no effect on cell proliferation. Dexamethasone alone and when combined with insulin or prolactin up-regulated gene expression of both PAI- and PAI-2 but not that of u-PA and u-PAR. Decreased total cell-associated, membrane-bound and secreted u-PA activity was detected in cells cultured in the presence of dexamethasone when combined with insulin or prolactin. However no such effect was observed in the presence of dexamethasone alone. Thus, dexamethasone acting synergistically with prolactin or insulin inhibits the activation of the plasmin-plasminogen system but this inhibition is not correlated with any changes in cell proliferation.

Effect of Escherichia coli lipopolysaccharide on u-PA activity and u-PA and u-PAR RNA expression in a bovine mammary epithelial cell line.

It is well known that the plasminogen-activating (PA) system plays a key role in the bovine mammary gland during tissue remodelling. However, the modulation of the PA cascade after bacterial infections needs to be elucidated. This study examined the effects of Escherichia coli lipopolysaccharide (LPS) on cell viability, the modulation of cell-associated u-PA activity, and the regulation of u-PA and u-PA receptor (u-PAR) RNA expression using the BME-UV1 bovine mammary epithelial cell line. LPS did not affect cell viability, but induced an increase in u-PA activity, with the maximum response after 6 h of incubation. Moreover, u-PA and u-PAR mRNA expression were both up-regulated in BME-UV1 cells after 3 h of incubation with LPS. These data indicated that E. coli LPS led to an increase in u-PA activity and RNA expression of u-PA and u-PAR in BME-UV1 cells, thus strengthening the role of the PA system during pathological processes.

Role of alpha-tocopherol in counteracting DNA damage induced by Ochratoxin A in primary porcine fibroblasts

Abstract Ochratoxin A is a mycotoxin responsible for disease states in both humans and animals. OTA mechanisms of action are numerous, including lipid peroxidation. Oxidative damage results in the modification of macromolecules (i.e. DNA), cell death and tissue injure. Several strategies, such as the use of antioxidants, have been used to reduce OTA cytotoxicity. The aim of this study was to evaluate the role of alpha-toco in counteracting DNA damage induced by OTA in cell cultures. Primary porcine fibroblasts, pherol isolated from embryo and from ear, were incubated for 24h with several concentrations of OTA in order to detect DNA fragmentation. OTA produced DNA fragmentation in a concentration dependent manner in both primary cell cultures. The pre-treatment with alpha-tocopherol caused the reduction of DNA fragmentation in both primary cell cultures, after 24h of incubation with OTA. In particular, when OTA was added at 10 μg/ml in embryo fibroblasts, alpha-tocopherol at the concentrations of 1 nM was significantly (P<0.05) able to reduce DNA fragmentation by 16%. In ear fibroblast cultures, alpha-tocopherol at the 1nM concentration was significantly (P<0.05) able to reduce DNA fragmentation by 15.23% in the presence of 5 μg/ml of OTA.

Folate, vitamin B12, alpha-tocopherol and selected liver components in periparturient dairy goats supplemented with choline and vitamin E

Abstract The influence of rumen-protected choline and vitamin E administration on status of folate, vitamin B12, and vitamin E and selected liver components was studied on 4 groups of 12 periparturient dairy goats: control, CTR; choline supplemented, RPC; vitamin E, VITE; choline and vitamin E, RPCE. Plasma folate did not differ between groups, except at parturition when RPC and RPCE goats had higher folate levels than CTR and VITE animals. Neither RPC nor vitamin E affected vitamin B12 plasma concentrations, while a time effect was observed after the third week of lactation, when B12 levels in each group started to increase. Alpha-tocopherol supplementation was associated with increased plasma α-tocopherol in the VITE and RPCE compared to the CRT and RPC groups, while RPC supplementation did not affect a-tocopherol levels in both RPC and RPCE groups compared to CTR and VITE ones. In control and RPC goats liver total lipid did not differ, while DNA contents and their ratio, were respectively higher and lower in RPC supplemented animals. Overall these results suggest that greater choline availability seems to be essential for optimising metabolic health and methyl group status, in dairy ruminants.

In vitro effects of lactoferrin on intestinal and mammary epithelial cell lines

Abstract Lactoferrin is an iron binding glycoprotein endowed with multiple functions, including non-specific immune defence against pathogens, immunomodulatory activity and regulation of cell growth. The gastrointestinal tract of the newborn and the mammary gland are targets of the biological action of lactoferrin. This work aimed at examining the effects of human and bovine lactoferrin on cell growth using intestinal and mammary epithelial cell lines and at evaluating the protective effect of bovine lactoferrin against cytotoxic damage induced by bacterial lipopolysaccharides in a bovine mammary epithelial cell line. It was shown that lactoferrin could be involved in regulating the growth of both intestinal and mammary epithelial cells depending on its concentrations, cell culture conditions and cell line used. The presence of lactoferrin binding sites on the cell surface was also discussed. Moreover, the data obtained suggested that bovine lactoferrin could contribute to counteract the effect of bacterial endotoxins.