ALPINE FARM SCALE INVESTIGATIONS OF THE RELATIONSHIPS BETWEEN PRODUCTIVE SYSTEM AND QUALITY OF DAIRY PRODUCTS

Alpine dairy farming is shifted from an extensive activity based on pasture and low genetic merit cow to an intensive system with specialized breeds and increasing level of concentrate as a supplement in the diet. As a main consequence, a lower echo-compatibility could determine adverse externalities on environment and quality of dairy products. Considering 18 dairy farming located in the mountain area of Veneto Region (Italy), the Environmental Summarizing Indicator (ESI) was estimated by using agronomic and dairying variables. Results indicated that variability of ESI was manly due to productive performance of dairy cows probably because there was a lack of information in the assessment of pasture characteristics. However, higher level of ESI were closely related to the increase of N-phile species and/or less attractive vegetation for grazing cows, even if the indicator seems to explain only a limited part of the variability of the phenomenon. The increase of ESI values seemed to lead to a loss of nutritive value of milk because of the incidence of health favourable fatty acids was reduced

Effect of period of milk production and ripening on quality traits of Asiago cheese

After 6 and 12 months of ripening, samples of Asiago d'Allevo were analyzed for quality traits. Cheeses were produced during 3 periods using milk from cows fed a total mixed ration (TMR, May) or grazing on alpine pasture (AG) in early (July) and late (Sept.) summer. Data were submitted to ANOVA considering ripening, milk production period and farm as main effects, and whole cheese weight as covariate. During ripening, pH of AGcheese was significantly lower than that of TMR-cheese; crude fat and protein significantly increased. According to period, July-samples showed the significantly lowest value of dry matter (DM), maybe due to a lower crude fat content; however, variability in skimming method could have altered proximate composition. No texture differences were found, although increasing weight of whole cheese significantly reduced max shear force as result of a lower DM content. Lightness (L*) and yellowness (b*) significantly decreased during ripening. AG feeding system caused a lower L* and higher b* than TMR one, probably as a consequence of a different amount of milk pigments. Cheese varied also within AG season: Sept.-samples showed the lowest L* value and the highest b*

PKA regulatory subunits mediate synergy among conserved G-protein-coupled receptor cascades

G-protein-coupled receptors sense extracellular chemical or physical stimuli and transmit these signals to distinct trimeric G-proteins. Activated Gα-proteins route signals to interconnected effector cascades, thus regulating thresholds, amplitudes and durations of signalling. Gαs- or Gαi-coupled receptor cascades are mechanistically conserved and mediate many sensory processes, including synaptic transmission, cell proliferation and chemotaxis. Here we show that a central, conserved component of Gαs-coupled receptor cascades, the regulatory subunit type-II (RII) of protein kinase A undergoes adenosine 3′-5′-cyclic monophosphate (cAMP)-dependent binding to Gαi. Stimulation of a mammalian Gαi-coupled receptor and concomitant cAMP-RII binding to Gαi, augments the sensitivity, amplitude and duration of Gαi:βγ activity and downstream mitogen-activated protein kinase signalling, independent of protein kinase A kinase activity. The mechanism is conserved in budding yeast, causing nutrient-dependent modulation of a pheromone response. These findings suggest a direct mechanism by which coincident activation of Gαs-coupled receptors controls the precision of adaptive responses of activated Gαi-coupled receptor cascades

Oxidative Stress in Cancer

Contingent upon concentration, reactive oxygen species (ROS) influence cancer evolution in apparently contradictory ways, either initiating/stimulating tumorigenesis and supporting transformation/proliferation of cancer cells or causing cell death. To accommodate high ROS levels, tumor cells modify sulfur-based metabolism, NADPH generation, and the activity of antioxidant transcription factors. During initiation, genetic changes enable cell survival under high ROS levels by activating antioxidant transcription factors or increasing NADPH via the pentose phosphate pathway (PPP). During progression and metastasis, tumor cells adapt to oxidative stress by increasing NADPH in various ways, including activation of AMPK, the PPP, and reductive glutamine and folate metabolism

Control of PKA stability and signalling by RING ligase praja2

Ligand-mediated activation of G-Protein Coupled Receptors (GPCRs) mobilises compartmentalised pulses of second messengers like cAMP. The main cellular effector of cAMP is Protein Kinase A (PKA) which is assembled as inactive holoenzyme consisting of two regulatory (R) and two catalytic (PKAc) subunits. cAMP binding to the R subunits dissociates the holoenzyme and releases the catalytic moiety, which phosphorylates a wide array of cellular proteins1. Re-association of the PKAc and R components terminates the signal. The rate of association and dissociation of R and PKAc subunits determines the intensity and the duration of the kinase activity, influencing complex biological phenotypes such as long term memory, differentiation and apoptosis2. Proteolysis of R subunits has been proposed as mechanism to sustain signalling downstream of PKAc3, although no enzyme targeting R subunits had been identified. Here we report that praja2, a RING E3 ligase widely expressed in mammalian cells, controls the stability of R subunits. Praja2 forms a stable complex with and is phosphorylated by PKA. Elevated cAMP levels promote Praja2-mediated ubiquitination and subsequent proteolysis of compartmentalised R subunits. Functional experiments in neuroblastoma cells and rat brains show that praja2 is required for efficient nuclear cAMP signalling and for PKA-mediated long-term potentiation (LTP). These findings indicate that praja2 regulates the total concentration of R subunits, thereby tuning the strength and duration of PKA signal output in response to the cAMP concentration

Control of mitochondria dynamics and oxidative metabolism by cAMP, AKAPs and the proteasome.

Mitochondria are highly specialized organelles and major players in fundamental aspects of cell physiology. In yeast, energy metabolism and coupling of mitochondrial activity to growth and survival is controlled by the protein kinase A pathway. In higher eukaryotes, modulation of the so-called A-kinase anchor protein (AKAP) complex regulates mitochondrial dynamics and activity, adapting the oxidative machinery and the metabolic pathway to changes in physiological demand. Protein kinases and phosphatases are assembled by AKAPs within transduction units, providing a mechanism to control signaling events at mitochondria and other target organelles. Ubiquitin-mediated proteolysis of signal transducers and effectors provides an additional layer of complexity in the regulation of mitochondria homeostasis. Genetic evidence indicates that alteration of one or more components of these biochemical pathways leads to mitochondrial dysfunction and human diseases. In this review, we focus on the emerging role of AKAP scaffolds and the proteasome pathway in the control of oxidative metabolism, organelle dynamics and the mitochondrial signaling network. These aspects are crucial elements for maintaining a proper energy balance and cellular lifespan

Evaluation of fast PCR reagents for rapid and sensitive detection of human herpesvirus 8.

The potential advantage of using fast PCR to detect human herpesvirus 8 (HHV-8) was tested by running a rapid cycling protocol (5 s-steps) in one standard and two fast ramping thermal cyclers to evaluate the performance of 8 different fast reagents. Under this extremely short time profile, assay sensitivity comparable to that of the original protocol was maintained using fast reagents from five suppliers. Reproducibility was higher using fast ramping thermal cyclers, suggesting that fast chemistry may be better matched with advanced instruments. Few fast reagents showed a 2-log-increase in sensitivity and good consistency, that allowed the substitution of the standard nested PCR method with the fast, single round technique. Overall, these studies indicate that some of the fast reagents tested may be used to perform a highly sensitive and reproducible HHV-8 detection with a considerable time saving