HDAC8 regulates canonical Wnt pathway to promote differentiation in skeletal muscles

Histone deacetylase 8 (HDAC8) is a class 1 histone deacetylase and a member of the cohesin complex. HDAC8 is expressed in smooth muscles, but its expression in skeletal muscle has not been described. We have shown for the first time that HDAC8 is expressed in human and zebrafish skeletal muscles. Using RD/12 and RD/18 rhabdomyosarcoma cells with low and high differentiation potency, respectively, we highlighted a specific correlation with HDAC8 expression and an advanced stage of muscle differentiation. We inhibited HDAC8 activity through a specific PCI-34051 inhibitor in murine C2C12 myoblasts and zebrafish embryos, and we observed skeletal muscles differentiation impairment. We also found a positive regulation of the canonical Wnt signaling by HDAC8 that might explain muscle differentiation defects. These findings suggest a novel mechanism through which HDAC8 expression, in a specific time window of skeletal muscle development, positively regulates canonical Wnt pathway that is necessary for muscle differentiation.     

Metabolic syndrome,Mediterranean diet,and polyphenols: Evidence and perspectives

Metabolic syndrome (MetS) is defined as the co-occurrence of metabolic risk factors that includes insulin resistance, hyperinsulinemia, impaired glucose tolerance, type 2 diabetes mellitus, dyslipidemia, and visceral obesity. The clinical significance of MetS consists of identifying a subgroup of patients sharing a common physiopathological state predisposing to chronic diseases. Clinical and scientific studies pinpoint lifestyle modification as an effective strategy aiming to reduce several features accountable for the risk of MetS onset. Among the healthy dietary patterns, the Mediterranean diet (MedDiet) emerges in terms of beneficial properties associated with longevity. Current evidence highlights the protective effect exerted by MedDiet on the different components of MetS. Interestingly, the effect exerted by polyphenols contained within the representative MedDiet components (i.e., olive oil, red wine, and nuts) seems to be accountable for the beneficial properties associated to this dietary pattern. In this review, we aim to summarize the principal evidence regarding the effectiveness of MedDiet–polyphenols in preventing or delaying the physiopathological components accountable for MetS onset. These findings may provide useful insights concerning the health properties of MedDiet–polyphenols as well as the novel targets destined to a tailored approach to MetS.     

Synthesis of lipopeptides of the immunodominant epitope hMBP(83–99) containing amide or C-C bond linked hydrophobic chains for the study of T cell response

We previously demonstrated that the lipopeptide of the myelin basic protein (MBP) immunodominant epitope in Lewis rat Palm-GpMBP(74–85) (Gp: guinea pig), which induced experimental autoimmune encephalomyelitis in vivo strongly increased the T cell proliferative response in vitro. We extended this study to the human immunodominant epitope hMBP(83–99), synthesizing different lipophilic peptides bearing a hydrophobic chain linked through an amide or a C-C bond. To this aim, we developed a synthetic pathway for (±)-N-Fmoc-Ahd-OH (Ahd: 2-aminohexadecanoic acid) which was used to synthesize diastereomeric peptides which were successfully separated by reverse-phase high-performance liquid chromatography. MBP-specific T cell lines recognizing the immunodominant epitope hMBP(83–99) have been generated from patients affected by multiple sclerosis. Their proliferative response to the native peptide and to some lipoderivatives has been investigated. In contrast to the animal model, none of the investigated lipopeptides exhibited superagonist activity.     

Potential Role of M. tuberculosis Specific IFN-γ and IL-2 ELISPOT Assays in Discriminating Children with Active or Latent Tuberculosis

Background

Although currently available IGRA have been reported to be promising markers for TB infection, they cannot distinguish active tuberculosis (TB) from latent infection (LTBI).

Objective

Children with LTBI, active TB disease or uninfected were prospectively evaluated by an in-house ELISPOT assay in order to investigate possible immunological markers for a differential diagnosis between LTBI and active TB.

Methods

Children at risk for TB infection prospectively enrolled in our infectious disease unit were evaluated by in-house IFN-γ and IL-2 based ELISPOT assays using a panel of Mycobacterium tuberculosis antigens.

Results

Twenty-nine children were classified as uninfected, 21 as LTBI and 25 as active TB cases (including 5 definite and 20 probable cases). Significantly higher IFN-γ ELISPOT responses were observed in infected vs. uninfected children for ESAT-6 (p<0.0001), CFP-10 (p<0.0001), TB 10.3 (p = 0.003), and AlaDH (p = 0.001), while differences were not significant considering Ag85B (p = 0.063), PstS1 (p = 0.512), and HspX (16 kDa) (p = 0.139). IL-2 ELISPOT assay responses were different for ESAT-6 (p<0.0001), CFP-10 (p<0.0001), TB 10.3 (p<0.0001), HspX (16 kDa) (p<0.0001), PstS1 (p<0.0001) and AlaDH (p = 0.001); but not for Ag85B (p = 0.063). Comparing results between children with LTBI and those with TB disease differences were significant for IFN-γ ELISPOT only for AlaDH antigen (p = 0.021) and for IL-2 ELISPOT assay for AlaDH (p<0.0001) and TB 10.3 antigen (p = 0.043). ROC analyses demonstrated sensitivity of 100% and specificity of 81% of AlaDH-IL-2 ELISPOT assay in discriminating between latent and active TB using a cut off of 12.5 SCF per million PBMCs.

Conclusion

Our data suggest that IL-2 based ELISPOT with AlaDH antigen may be of help in discriminating children with active from those with latent TB.     

Neglect of a Neglected Disease in Italy: The Challenge of Access-to-Care for Chagas Disease in Bergamo Area

ObjectivesChagas disease (CD) represents a growing problem in Europe; Italy is one of the most affected countries but there is no national framework for CD and access-to-care is challenging. In 2012 Médecins Sans Frontières (MSF) started an intervention in Bergamo province, where many people of Latin American origin (PLAO) are resident. A new model-of-care for CD, initiated by Centre for Tropical Diseases of Sacro Cuore Hospital, Negrar (CTD), the NGO OIKOS and the Bolivian community since 2009 in the same area, was endorsed. Hereby, we aim to describe the prevalence of CD and the treatment management outcomes among PLAO screened from 1^st June 2012 to 30^th June 2013.MethodsRetrospective cohort study using routine program data. Screening sessions were done in Bergamo at OIKOS outpatient service and serological confirmation, staging and treatment for CD was offered at the CTD. MSF provided health education on CD, awareness generation prior to screening days, pre-test and post-test counselling through cultural mediators of Latin American origin.ResultsOf 1305 PLAO screened, 223(17%) had CD. Among 210 patients eligible for treatment, 102(49%) were lost-to-follow-up before treatment. The median delay from diagnosis to treatment was 4 months (range 0.7–16.6 months). Among 108 started on treatment, 63(58%) completed treatment, 36(33%) interrupted treatment, (33 for drug side-effects, two for patients decision and one due to pregnancy), 6(6%) were lost-to-follow-up and 3(3%) were on treatment at study censuring.ConclusionIn this first study focusing on process of care for CD in Italy, less than 30% of patients completed treatment with drop-outs along the cascade of care. There is an urgent need to involve affected communities and local regional health authorities to take part to this model-of-care, adapting it to the local epidemiology. The Italian health authorities should take steps in advocating for a change in the current paradigm.     

Genome comparisons indicate recent transfer of wRi‐like Wolbachia between sister species Drosophila suzukii and D. subpulchrella

Wolbachia endosymbionts may be acquired by horizontal transfer, by introgression through hybridization between closely related species, or by cladogenic retention during speciation. All three modes of acquisition have been demonstrated, but their relative frequency is largely unknown. Drosophila suzukii and its sister species D. subpulchrella harbor Wolbachia, denoted wSuz and wSpc, very closely related to wRi, identified in California populations of D. simulans. However, these variants differ in their induced phenotypes: wRi causes significant cytoplasmic incompatibility (CI) in D. simulans, but CI has not been detected in D. suzukii or D. subpulchrella. Our draft genomes of wSuz and wSpc contain full‐length copies of 703 of the 734 single‐copy genes found in wRi. Over these coding sequences, wSuz and wSpc differ by only 0.004% (i.e., 28 of 704,883 bp); they are sisters relative to wRi, from which each differs by 0.014%–0.015%. Using published data from D. melanogaster, Nasonia wasps and Nomada bees to calibrate relative rates of Wolbachia versus host nuclear divergence, we conclude that wSuz and wSpc are too similar—by at least a factor of 100—to be plausible candidates for cladogenic transmission. These three wRi‐like Wolbachia, which differ in CI phenotype in their native hosts, have different numbers of orthologs of genes postulated to contribute to CI; and the CI loci differ at several nucleotides that may account for the CI difference. We discuss the general problem of distinguishing alternative modes of Wolbachia acquisition, focusing on the difficulties posed by limited knowledge of variation in absolute and relative rates of molecular evolution for host nuclear genomes, mitochondria, and Wolbachia.     

Transgenic mice expressing F3/contactin from the TAG-1 promoter exhibit developmentally regulated changes in the differentiation of cerebellar neurons

F3/contactin (CNTN1) and TAG-1 (CNTN2) are closely related axonal glycoproteins that are differentially regulated during development. In the cerebellar cortex TAG-1 is expressed first as granule cell progenitors differentiate in the premigratory zone of the external germinal layer. However, as these cells begin radial migration, TAG-1 is replaced by F3/contactin. To address the significance of this differential regulation, we have generated transgenic mice in which F3/contactin expression is driven by TAG-1 gene regulatory sequences, which results in premature expression of F3/contactin in granule cells. These animals (TAG/F3 mice) display a developmentally regulated cerebellar phenotype in which the size of the cerebellum is markedly reduced during the first two postnatal weeks but subsequently recovers. This is due in part to a reduction in the number of granule cells, most evident in the external germinal layer at postnatal day 3 and in the inner granular layer between postnatal days 8 and 11. The reduction in granule cell number is accompanied by a decrease in precursor granule cell proliferation at postnatal day 3, followed by an increase in the number of cycling cells at postnatal day 8. In the same developmental window the size of the molecular layer is markedly reduced and Purkinje cell dendrites fail to elaborate normally. These data are consistent with a model in which deployment of F3/contactin on granule cells affects proliferation and differentiation of these neurons as well as the differentiation of their synaptic partners, the Purkinje cells. Together, these findings indicate that precise spatio-temporal regulation of TAG-1 and F3/contactin expression is critical for normal cerebellar morphogenesis.