The New Modern Mediterranean Diet Italian Pyramid

BACKGROUND

Epidemiological studies have established the health benefits associated with the adherence to the MD (Mediterranean Diet), mainly in relation to reducing the risk of developing the non communicable diseases. The MD is a sustainable diet model that respects the environment, promotes the bio-diversity, the local cultural heritages, the social interaction and economic aspects.

METHODS

The pyramid is a graphical representation designed to represent the frequencies of consumption and portion sizes of each food according to the Mediterranean model and tradition. The pyramid was developed taking into account the LARN (Reference Intake of nutrients and energy for Italian Population) and the Italian Guidelines for a healthy diet.

RESULTS

The frequency of consumption and the portion size recommended are located at the different level of the pyramid. At the base of the pyramid there are the foods that should be consumed every meal and some concepts typical of the Mediterranean culture. In the middle there are foods that should be consumed daily and at the top of the pyramid the foods consumed on a weekly basis.

CONCLUSIONS

The new modern MD Italian Pyramid is an important tool to promote the MD and improve the adherence to the MD dietary pattern.

The yogurt amino acid profile's variation during the shelf-life

OBJECTIVE

To analyze the yogurt amino acid profile starting from marketing through the whole shelf-life. The evaluation of the proteolytic activity of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus, allows to deduce their vitality during the shelf-life period and within 45 days.

METHODS

Three types of full fats yogurts have been analyzed (a) natural white (b) sweet white and (c) whole fruit - in two stages: t0 (first day of shelf-life) and t1 (end of shelf-life). The proteins have been analyzed by the Kjeldahl method and the amino acid profile by HPLC.

RESULTS

In natural yogurt a significant increase of the amount of free amino acids has been observed during the period of shelf-life (97%). In the sweetened full fats and fruit yogurt, instead, there is a lower increase of respectively 33% and 39%

CONCLUSIONS

In whole milk natural yogurt, based on our data, the proteolytic activity seems to persist during the entire period of the shelf-life and this can be considered an index of bacterial survival, especially of Lactobacillus delbrueckii subsp. bulgaricus during the marketing process.

Pre-culturing human adipose tissue mesenchymal stem cells under hypoxia increases their adipogenic and osteogenic differentiation potentials

OBJECTIVES

Hypoxia is an important factor in many aspects of stem-cell biology including their viability, proliferation, differentiation and migration. We evaluated whether low oxygen level (2%) affected human adipose tissue mesenchymal stem-cell (hAT-MSC) phenotype, population growth, viability, apoptosis, necrosis and their adipogenic and osteogenic differentiation potential.

MATERIALS AND METHODS

hAT-MSCs from four human donors were cultured in growth medium under either normoxic or hypoxic conditions for 7 days and were then transferred to normoxic conditions to study their differentiation potential.

RESULTS

Hypoxia enhanced hAT-MSC expansion and viability, whereas expression of mesenchymal markers such as CD90, CD73 and endothelial progenitor cell marker CD34, remained unchanged. We also found that pre-culturing hAT-MSCs under hypoxia resulted in their enhanced ability to differentiate into adipocytes and osteocytes.

CONCLUSIONS

This protocol could be useful for maximizing hAT-MSC potential to differentiate in vitro into the adipogenic and osteogenic lineages, for use in plastic and reconstructive surgery, and in tissue engineering strategies.

High mobility group box 1 is a novel substrate of dipeptidyl peptidase-IV

AIMS/HYPOTHESIS

High mobility group box 1 (HMGB1) is a cytokine with a key role in tissue regeneration and angiogenesis. Previous studies have shown that topical application of HMGB1 to skin wounds of mouse models of diabetes enhanced vessel density and accelerated wound healing, suggesting that diabetes may affect endogenous HMGB1 functions. Dipeptidyl peptidase IV (DPP-IV/CD26) is a protease whose activity is increased in diabetes and whose inhibition improves glucose tolerance. Since HMGB1 contains potential DPP-IV cleavage sites, we determined whether HMGB1 may be a substrate for DPP-IV and whether DPP-IV-mediated cleavage may alter the biological activity of HMGB1.

METHODS

Reversed phase HPLC, mass spectrometry and western blot analyses were performed to analyse and identify HMGB1 peptides generated following DPP-IV digestion. HMGB1 angiogenic functions in the presence of DPP-IV were evaluated in vitro and in vivo. HMGB1 protein was detected in the serum of type 2 diabetic patients before and after treatment with DPP-IV inhibitors.

RESULTS

DPP-IV cleaved HMGB1 at its N-terminal region and affected its angiogenic functions. Specifically, DPP-IV inhibited HMGB1-induced endothelial cell migration and capillary-like structure formation, as well as HMGB1-mediated vascular network formation in Matrigel implants in mice. We had previously found that HMGB1 promoted endothelial cell migration through activation of extracellular regulated kinase signalling pathway. Here we showed that such an effect was abolished in the presence of DPP-IV. Finally, the N-terminal truncated form of HMGB1 was detected in the serum of type 2 diabetic patients, in whom DPP-IV inhibitors enhanced the levels of full-length HMGB1.

CONCLUSIONS/INTERPRETATION

DPP-IV cleaves HMGB1 and, via this mechanism, inhibits HMGB1 angiogenic activity. Treatment with DPP-IV inhibitors may enhance HMGB1 activity in diabetic patients, thereby improving angiogenesis in this condition.

A crosstalk between hSiah2 and Pias E3-ligases modulates Pias-dependent activation

Protein inhibitor of activated STAT (Pias) and human homologues of seven in absentia (hSiah) proteins both exhibit properties of ubiquitin-family peptides conjugating enzymes. Pias present E3-ligase activity for small ubiquitin-related modifiers (Sumo) covalent attachment to their targets. This post-translational modification is responsible for the activation of different transcription factors such as AP1. HSiah proteins possess ubiquitin-E3-ligase activity that triggers their partners to proteasomal-dependent degradation. The present study identifies Pias as a new hSiah2-interacting protein. We demonstrate that hSiah2 regulates specifically the proteasome-dependent degradation of Pias proteins. On reverse, Pias does not prevent hSiah2 degradation. We provide evidences for hSiah2-dependent degradation of Pias as being a mechanism in the regulation of c-jun N-terminal kinase-activating pathways. This report describes a new interconnection between sumoylation and ubiquitination pathways by regulating the levels of the E3-ligases available for these processes.

The exon 7-spliced Lck isoform in T lymphocytes: a potential regulator of p56lck signaling pathways

The protein-tyrosine kinase p56lck is the product of the lck gene. It plays a pivotal role in T-lymphocyte activation and thymocyte development, as indicated by the defective immune responses of lck-/- mice. We have demonstrated that an exon 7-deleted lck mRNA is produced by alternative splicing in all human cells expressing the lck gene. We have now looked for the protein encoded by this spliced lck mRNA and attempted to determine the function of the deleted Lck protein. This paper shows that the LckDelta7 protein is present in JCaM1.6 T-cells and we inferred that this isoform accounts for 15% of the total Lck proteins in the parental Jurkat T-cell line. We report that deletion of the first 51 amino-acids (exon 7) of the Lck catalytic domain greatly reduces the kinase activity of the recombinant protein. The residual activity can, nevertheless, be enhanced by adding Mn(2+), whereas this cation has no effect on the activity of the p56lck mutated in its active site (K273E). The enforced production of LckDelta7 protein in transfected Jurkat cells results in slower cell proliferation than does p56lck. These findings suggest that the LckDelta7 protein is a p56lck cell-signaling regulator. This mechanism could be common to both humans and mice, in which we also found the exon 7-spliced lck transcript.

SIAH-1 interacts with alpha-tubulin and degrades the kinesin Kid by the proteasome pathway during mitosis

SIAH-1, a human homologue of the Drosophila seven in absentia (Sina), has been implicated in ubiquitin-mediated proteolysis of different target proteins through its N-terminal RING finger domain. SIAH-1 is also induced during p53-mediated apoptosis. Furthermore, SIAH-1-transfected breast cancer cell line MCF-7 exhibits an altered mitotic process resulting in multinucleated giant cells. Now, using the two-hybrid system, we identified two new SIAH interacting proteins: Kid (kinesin like DNA binding protein) and alpha-tubulin. We demonstrate that SIAH is involved in the degradation of Kid via the ubiquitin-proteasome pathway. Our results suggest that SIAH-1 but not its N-terminal deletion mutant, affects the mitosis by an enhanced reduction of kinesin levels. Our results imply, for the first time, SIAH-1 in regulating the degradation of proteins directly implicated in the mitotic process.

SIAH-1 inhibits cell growth by altering the mitotic process

SIAH-1, the human homologue of the drosophila seven in absentia gene, is a p53-p21Waf-1 inducible gene. We report that stable transfection with SIAH-1 of the epithelial breast cancer cell line MCF-7 blocks its growth process. The transfectants show a redistribution of SIAH-1 protein within the nucleus, more specifically to the nuclear matrix, associated to dramatic changes in cell morphology and defective mitosis. Multinucleated giant cells (2-12 nuclei in more than 50% cells) were a most striking observation associated with tubulin spindle disorganization and defective cytokinesis. There were also present at high frequency abortive mitotic figures, DNA bridges and persistance of intercellular bridges and midbodies, along with an increased expression of p21Waf-1. These results indicate that the mechanism of growth arrest induced by SIAH-1 in MCF-7 cells involves disorganization of the mitotic program, mainly during nuclei separation and cytokinesis.

hSiah2 is a new Vav binding protein which inhibits Vav-mediated signaling pathways

The hematopoietic proto-oncogene vav has been characterized as a Rac1-GDP/GTP exchanger protein which regulates cytoskeletal reorganization as well as signaling pathways leading to the activation of stress-activated protein kinases (SAPK/JNKs). Furthermore, vav overexpression enhances basal and T-cell receptor (TCR)-mediated stimulation of the nuclear factor of activated T cells (NFAT). We report here the interaction between Vav and hSiah2, a mammalian homolog of Drosophila Seven in absentia (Sina) that has been implicated in R7 photoreceptor cell formation during Drosophila eye development via the proteasome degradation pathway. Vav and hSiah2 interact in vitro and in vivo and colocalize in the cytoplasm of hematopoietic cells. The Src homology domain of Vav and the C-terminal region of hSiah2 are required for this interaction. We provide evidence for a negative regulation by hSiah2 of Vav-induced basal and TCR-mediated NFAT-dependent transcription. Overexpression of hSiah2 also inhibits the onco-Vav-induced JNK activation. Although the Vav-interacting domain is located in the C-terminal portion of hSiah2, the N-terminal region of hSiah2 is necessary for the inhibitory role that seems to be independent of the proteasome degradation.

Intrauterine growth retardation: evidence for the activation of the insulin-like growth factor (IGF)-related growth-promoting machinery and the presence of a cation-independent IGF binding protein-3 proteolytic activity by two months of life

Thirty-seven children with intrauterine growth retardation (IUGR) were enrolled in a 3-mo longitudinal study. Weight, length, and knee-heel length (by knemometry) were measured at birth and at 7, 14, 30, 60, and 90 d. GH, IGF-I, IGF binding protein (BP)-3, IGFBP-1, and C-peptide were measured at birth and at 2 mo. IGFBP-3 Western immunoblotting and proteolytic activity assay were also performed. Twenty-five newborns with birth weight appropriate for gestational age were chosen as controls. At birth IUGR newborns showed levels of GH and IGFBP-1 significantly higher, and IGF-I, IGFBP-3, and C-peptide significantly lower than control subjects. At 2 mo GH and IGFBP-1 levels decreased, whereas IGF-I, IGFBP-3, and C-peptide rose, attaining the concentrations found in control subjects at birth. Baseline peptide levels as well as their 2-mo variations did not correlate with the gain in weight, supine length, and knee-heel length recorded at 3 mo. Fourteen of nineteen IUGR cord blood samples showed the presence of the intact approximately 42-39-kD IGFBP-3 doublet and the major approximately 29-kD fragment. At 2 mo the IGFBP-3 band pattern was characterized by the predominance of a approximately 18-kD fragment in 6 of 19 tested IUGR infants. The incubation of 2-mo IUGR samples with normal adult serum induced the appearance of the approximately 18-kD band, which was not modified by the addition of EDTA. These results suggest that: 1) the IGF-related growth-promoting mechanism is impaired in IUGR children at birth but is fully restored at 2 mo; 2) the cord blood levels of GH, IGF-I, IGFBP-3, IGFBP-1, and C-peptide are not predictive of the weight and length gain during the first 3 mo of life; 3) IUGR children have at least two different IGFBP-3 proteases, one cation-dependent protease that is present at birth and able to yield the major approximately 29-kD IGFBP-3 fragment and a second one, with a different activation timing, which exhibits cation independence and induces the formation of a approximately 18-kD IGFBP-3 form.

Vav binding to heterogeneous nuclear ribonucleoprotein (hnRNP) C. Evidence for Vav-hnRNP interactions in an RNA-dependent manner

The vav proto-oncogene is exclusively expressed in hematopoietic cells and encodes a 95-kDa protein that contains multiple structural domains. Vav is involved in the expansion of T and B cells, in antigen-mediated proliferative responses, and in the induction of intrathymic T cell maturation. It becomes rapidly and transiently tyrosine-phosphorylated upon triggering of a large number of surface receptors and catalyzes GDP/GTP exchange on Rac-1. We now provide evidence for the specific interaction of Vav with heterogeneous nuclear ribonucleoprotein (hnRNP) C. Vav and hnRNP C interact both in vivo and in vitro mediated through the carboxyl Src homology 3 domain of Vav and the proline-rich motif located in the nuclear retention sequence of hnRNP C. More importantly, Vav-hnRNP C complexes are present in living hematopoietic cells and both proteins localize in the nuclei, mainly on perichromatic fibrils but also on clusters of interchromatin granules. The Vav-hnRNP C interaction is regulated by poly(U) RNA, although a basal association is still detected in the absence of RNA. Furthermore, RNA homopolymers differentially alter the binding affinity of Vav to hnRNP C and hnRNP K. We propose that Vav-hnRNP interactions may be established in an RNA-dependent manner.

Uncoupling of p21 induction and MyoD activation results in the failure of irreversible cell cycle arrest in doxorubicin-treated myocytes

Doxorubicin (Dox, Adriamicin), a potent broad spectrum anthracycline anticancer drug, selectively inhibits muscle specific gene expression in cardiac cells in vivo and prevents terminal differentiation of skeletal muscle cells in vitro. By inducing the expression of the helix-loop-helix (HLH) transcriptional inhibitor ld2, Dox represses the myogenic function of the MyoD family of muscle regulatory factors (MRFs). In many cell types, terminal differentiation is coupled to an irreversible exit from the cell cycle and MyoD plays a critical role in the permanent cell cycle arrest of differentiating myocytes by upregulating the cyclin dependent kinase inhibitor (cdki) p21. Here, we correlate Dox effects on cell cycle with changes of E2F/DP complexes and activity in differentiating C2C12 myocytes. In Dox-treated quiescent myoblasts, which fail to differentiate into myotubes under permissive culture conditions, serum re-stimulation induces cyclin/cdk re-association on the E2F/DP complexes and this correlates with an evident increase in E2F/DP driven transcription and re-entry of myoblasts into the cell cycle. Despite Dox ability to activate the DNA-damage dependent p53/p21 pathway, when induced in the absence of MyoD or other MRFs, p21 fails to maintain the postmitotic state in Dox-treated myocytes induced to differentiate. Thus, uncoupling p21 induction and MyoD activity results in a serum-reversible cell cycle arrest, indicating that MRF specific activation of cdki(s) is required for permanent cell cycle arrest in differentiating muscle cells.

Enhanced expression of myogenic regulatory genes in aging skeletal muscle

MyoD, myogenin, myf-5, and MRF4, belonging to the family of basic helix-loop-helix (bHLH) myogenic regulatory factors (MRFs), control muscle cell differentiation, in concert with other transcription factors such as MEF-2, yet their role in age-related skeletal muscle alteration has not been addressed. We here report that MyoD and myogenin transcripts are expressed at high levels in the hind limb muscles of newborn mice and their level of expression continuously declines throughout postnatal life to become virtually undetectable in the adult mouse. However, these transcripts are again expressed at high levels in the muscles of older mice. MRF4 transcript, on the other hand, is present at a constant level throughout the life span of the animal. Conversely, the expressions of myf-5 and MEF-2C, components of the autoregulatory loop for the activation of bHLH gene expression, conspicuously increase in adult and senile muscle. In order to establish whether these transcripts are functioning in the aged muscle we investigated the expression of bHLH inhibitory factor Id mRNA showing that it does not present significant changes during aging. Immunofluorescence analysis with an anti-myogenin antibody revealed nuclear accumulation of the protein in the muscle fibers of old, but not of adult, mice. Muscle-specific genes transactivated by MyoD and myogenin such as AChR, MLC, and MCK are also up-regulated during aging, albeit at a lower level. Significant changes in the size and ratio of type I/type II fibers are detectable in senile muscle. These findings show that all members of the MRF family are expressed to a high extent and are likely active in senile muscle. It is conceivable that these changes might operate as a compensatory mechanism in maintaining the expression of differentiated muscle products in senile muscle at a steady-state level.

TPA-induced differentiation of human rhabdomyosarcoma cells involves dephosphorylation and nuclear accumulation of mutant P53

Previous studies have shown that human rhabdomyosarcoma cells are induced to differentiate by TPA, in the absence of appreciable alterations of the muscle regulatory genes and their products (1). The question was addressed whether the tumor suppressor p53 could be a target of TPA action in these cells. Genomic analysis by a Polymerase Chain Reaction/Single-Strand Conformation Polymorphism (PCR/SSCP) and direct sequencing indicate the presence of a mutation in exon VII at codon 248 (C to T transition) and a loss of heterozygosity of p53 gene in human rhabdomyosarcoma cell line (RD). It is here shown that transcription of p53 mRNA strongly decreases in RD cells induced to growth arrest and differentiate by TPA treatment. In these cells immunoprecipitation and immunoblot analysis show that both synthesis and total cellular concentration of the protein are also reduced by TPA. Nevertheless nuclear p53 accumulation is at much higher extent, whereas 32P-orthophosphate labelling, followed by immunoprecipitation, demonstrates a decrease of phosphorylation of both cytoplasmic and nuclear p53. These results indicate that TPA causes a number of alterations of mutant p53, likely mediated through a protein kinase C dependent mechanism, which might impair the transforming ability of mutant p53 in growth-arrested and differentiating RD cells.

Stereometry in very close-range stereophotogrammetry with non-metric cameras for human movement analysis

In this paper a stereophotogrammetric algorithm based on a black-box approach to the modelling of object to image spaces relationship is proposed. The algorithm is well suited for 'very close-range photogrammetry', with respect to experiments in which the measurement field is 0.5 X 0.5 X 0.5 m or smaller, as in the analysis of a few or small body segments movements. The attainable accuracy is high, better than 0.1% of the observation distance. Non-professional and even different cameras can be used. Consequently an inexpensive experimental set-up can be realized. A very simple, cheap and easily usable calibration object is needed. Computation time for the reconstruction of object-space co-ordinates of point body landmarks is one order of magnitude lower than in the case of the Direct Linear Transformation (DLT) (Abdel Aziz and Karara, Proceedings of the ASP/U1 Symposium on Close-Range Photogrammetry, pp. 1-18. American Society of Photogrammetry, 1971; Marzan and Karara, Proceedings of the Symposium on close-range Photogrammetric Systems, pp. 420-467. American Society of Photogrammetry, 1975). Computation time for calibration is two-fold in respect of the DLT. An example of application to the recording of the movements of the index finger with respect to the metacarpophalangeal joint is given.

Analysis of DNA synthesis rate of cultured cells from flow cytometric data

The rate of DNA synthesis along S phase is estimated from flow cytometric histograms on the basis of a mathematical model of a cell population. In the absence of loss, the model expresses the population kinetics in terms of DNA synthesis rate, S-phase influx, and population size. A single histogram is sufficient to determine the DNA synthesis rate when the population is in balanced exponential growth. Two suitably chosen histograms are necessary if the S-phase influx is exponential in a time interval longer than the S-phase duration. The analysis procedure was tested on published autoradiographic data and applied to three cultured cell lines (CM-S, 3LL, and M14 cells) that show various patterns of DNA distribution. In each case the cell-cycle fractions, the DNA synthesis rate, and the S-phase duration were obtained.

Analysis of the parameter constraints for a proposed antibody affinity distribution

The problem of recovering the affinity distribution in the immune response from experimental binding data is considered. Starting from a previously proposed analytical expression for this distribution the study of the parameter constraints has been completed in order to guarantee the physical meaning of the results.

Estimation of cell DNA synthesis rate from flow-cytometric histograms

The rate of DNA synthesis along S-phase can be estimated on the basis of a simple model of a cell population, from a single FCM histogram under conditions of balanced exponential growth, and from two histograms suitably spaced in time under conditions of locally exponential S-phase influx. An algorithm that constructs a piecewise constant approximation of the synthesis rate and estimates the phase fractions from a single histogram is presented. The results of the application of the algorithm to a set of computer generated histograms in balanced exponential growth are reported.

A general expression for sequential DNA-fluorescence histograms

A general expression for time sequences of DNA-fluorescence histograms from flow microfluorometry is given in this paper. Such expression is given in terms of the law of DNA growth along S phase, the flux of cells into S, and the efflux out of M. Special conditions of growth (e.g. the exponential steady-state growth), and the case of blocks in S phase are also analyzed. Some simulations of the expressions obtained are presented.