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Down syndrome (DS), a complex disorder that is caused by the trisomy of chromosome 21 (Hsa21), is a major cause of congenital heart defects (CHD). Interestingly, only about 50% of individuals with Hsa21 trisomy manifest CHD. Here we review the genetic basis of CHD in DS, focusing on genes that regulate extracellular matrix (ECM) organization. The overexpression of Hsa21 genes likely underlies the molecular mechanisms that contribute to CHD, even though the genes responsible for CHD could only be located in a critical region of Hsa21. A role in causing CHD has been attributed not only to protein-coding Hsa21 genes, but also to genes on other chromosomes, as well as miRNAs and lncRNAs. It is likely that the contribution of more than one gene is required, and that the overexpression of Hsa21 genes acts in combination with other genetic events, such as specific mutations or polymorphisms, amplifying their effect. Moreover, a key function in determining alterations in cardiac morphogenesis might be played by ECM. A large number of genes encoding ECM proteins are overexpressed in trisomic human fetal hearts, and many of them appear to be under the control of a Hsa21 gene, the RUNX1 transcription factor.

Simple Summary Down Syndrome, which is due to the presence of three copies of chromosome 21, always presents with mental retardation, possibly caused by defects in the development of neurons. In recent years, it has been shown that cells and tissues in Down syndrome manifest alterations in the function of mitochondria, the organelles that provide energy to cells. We hypothesized that mitochondrial dysfunction might contribute to the defect in neuronal cell development. To test this hypothesis, we generated a model of stem cells that, upon specific treatments, are capable of giving rise to neuronal cells, as evidenced by the synthesis of specific proteins. We observed that stem cells derived from Down syndrome individuals, after 21 days of growth in an artificial system, had an abnormal tendency to develop as glial cells, compared with control cells. As early as day 7 of culture, the trisomic cells also exhibited defects in mitochondrial function, such as anomalies in their calcium level, oxygen free radicals, oxygen consumption, and synthesis of ATP, a molecule that is critical in energy conversions. These results indicate that alterations in neuronal development and mitochondrial function occur early in this model, which we think is suitable for answering further questions. Abstract Background: The presence of mitochondrial alterations in Down syndrome suggests that it might affect neuronal differentiation. We established a model of trisomic iPSCs, differentiating into neural precursor cells (NPCs) to monitor the occurrence of differentiation defects and mitochondrial dysfunction. Methods: Isogenic trisomic and euploid iPSCs were differentiated into NPCs in monolayer cultures using the dual-SMAD inhibition protocol. Expression of pluripotency and neural differentiation genes was assessed by qRT-PCR and immunofluorescence. Meta-analysis of expression data was performed on iPSCs. Mitochondrial Ca2+, reactive oxygen species (ROS) and ATP production were investigated using fluorescent probes. Oxygen consumption rate (OCR) was determined by Seahorse Analyzer. Results: NPCs at day 7 of induction uniformly expressed the differentiation markers PAX6, SOX2 and NESTIN but not the stemness marker OCT4. At day 21, trisomic NPCs expressed higher levels of typical glial differentiation genes. Expression profiles indicated that mitochondrial genes were dysregulated in trisomic iPSCs. Trisomic NPCs showed altered mitochondrial Ca2+, reduced OCR and ATP synthesis, and elevated ROS production. Conclusions: Human trisomic iPSCs can be rapidly and efficiently differentiated into NPC monolayers. The trisomic NPCs obtained exhibit greater glial-like differentiation potential than their euploid counterparts and manifest mitochondrial dysfunction as early as day 7 of neuronal differentiation.

Background The phenotype of early embryonic fourth branchial arch defects encompasses a wide spectrum of clinical conditions including DiGeorge syndrome (DGS), velocardiofacial syndrome, and conotruncal anomaly face syndrome. The majority of the patients have a 22q11.2 deletion. However, in 6% to 17% of patients, the identification of a genetic cause remains unknown through fluorescence in situ hybridization. In these patients, the clinical features and the immunological abnormalities are not well defined. Objective To describe the main genomic abnormalities, clinical features, and immunological abnormalities of a cohort of patients resembling the 22q11.2 deletion phenotype in the absence of 22q11.2 locus alterations. Methods Eleven patients from unrelated nonconsanguineous families with suspected 22q11.2 deletion syndrome (22q11.2DS) according to Tobias criteria were enrolled. Array-comparative genomic hybridization was performed in 10 patients. A phenotypic and immunological assessment was performed in all patients. Results The majority of patients had a phenotype overlapping with 22q11.2DS and immunological abnormalities suggestive of abnormalities in T-cell development, being severe in 2 of them. Most subjects suffered from recurrent infections. Clinically overt autoimmune manifestations were identified in 2 (18%) subjects. New pathogenic or likely pathogenic genomic regions associated with 22q11.2DS features were identified. Conclusion Patients with a DGS-like phenotype share the same features of the classical 22q11.2DS associated with other rare genomic alterations. Severe forms of immunodeficiency may also be observed in this group.

Mitochondria are organelles that mainly control energy conversion in the cell. In addition, they also participate in many relevant activities, such as the regulation of apoptosis and calcium levels, and other metabolic tasks, all closely linked to cell viability. Functionality of mitochondria appears to depend upon their network architecture that may dynamically pass from an interconnected structure with long tubular units, to a fragmented one with short separate fragments. A decline in mitochondrial quality, which presents itself as an altered structural organization and a function of mitochondria, has been observed in Down syndrome (DS), as well as in aging and in age-related pathologies. This review provides a basic overview of mitochondrial dynamics, from fission/fusion mechanisms to mitochondrial homeostasis. Molecular mechanisms determining the disruption of the mitochondrial phenotype in DS and aging are discussed. The impaired activity of the transcriptional co-activator PGC-1α/PPARGC1A and the hyperactivation of the mammalian target of rapamycin (mTOR) kinase are emerging as molecular underlying causes of these mitochondrial alterations. It is, therefore, likely that either stimulating the PGC-1α activity or inhibiting mTOR signaling could reverse mitochondrial dysfunction. Evidence is summarized suggesting that drugs targeting either these pathways or other factors affecting the mitochondrial network may represent therapeutic approaches to improve and/or prevent the effects of altered mitochondrial function. Overall, from all these studies it emerges that the implementation of such strategies may exert protective effects in DS and age-related diseases.

Background Schizophrenia (SCZ) is a debilitating mental illness characterized by a highly complex, heterogeneous, non-mendelian genetic background. Recent progress in dissecting genetic architecture of SCZ has accelerated over the last decade due to new advanced technologies. Genome-Wide Association Studies (GWAS) on extremely large samples of patients identified and replicated hundreds of Single-Nucleotide Polymorphism (SNPs), each exhibiting only a modest effect. The analysis of genomic Copy Number Variations (CNVs) clarified the role of rare structural variants conferring significant risk by disrupting multiple genes involved in neurodevelopmental pathways, and linked to SCZ. In this scenario, the aim of our study is to carry out a genetic characterization of a cohort of patients affected by SCZ, in order to assess the risk of recurrence, to elucidate putative pathogenetic mechanisms and, whenever possible, to conceive tailored interventions and therapies. Methods 34 patients (8 women and 26 men) affected by SCZ and admitted to Day Hospital at Psychiatric Division for Treatment Resistant Psychosis of the University of Naples Federico II were recruited, and underwent: i) psychopathological evaluation and assessment of clinical response to antipsychotics; ii) genetic counseling; iii) further diagnostic investigation by using Comparative Genomic Hybridization (CGH) + Single Nucleotide Polymorphism (SNP) microarray with 2x400k Agilent’s platform “GenetiSure” for detecting unbalanced chromosomal abnormalities and regions of homozygosity (ROHs). Results Structural pathogenetic rearrangements resulted in 9 (27%) patients. Those identified were the following: 15q13.3 deletion, 16p13.11 duplication, 22q11.22 deletion (TOP3B), 22q11.22 (PRODH, DGCR5, DGCR6), RBFOX1 deletion, TCF4 deletion, derivative X chromosome (X;Y translocation). Potentially pathogenic rearrangements, involving genes associated with psychiatric disorders or implicated in neurodevelopment, resulted in 15 patients (44%). No relevant CNVs were detected in 10 patients (29%), although they showed the presence of ROHs that may contain susceptibility loci, since many neurodevelopmental genes map onto or near these specific regions. Certain of these rearrangements occur in many patients, and certain patients showed likewise multiple rearrangements. Discussion The analysis of CNVs and SNPs allowed us to characterize the genetic disease structure in the whole cohort of patients and helped to refine the diagnosis in a few cases, thereby ascertaining an underlying specific genetic condition. A further extension of the study, in terms of sample size and more accurate investigations (i.e genetic mapping of ROHs) is underway. According to literature, rare risk-associated CNVs account for 2% of SCZ cases, but their higher prevalence (27%) in our sample may be influenced by a larger percentage of Treatment Resistant and more severely ill patients (since they were recruited in a highly specialized Unit for Treatment Resistant Psychosis). Therefore, our future purpose is to demonstrate a robust genetic modulation of Treatment Resistant endophenotypes of SCZ. Moreover, we believe that the role of genetic counseling in psychiatric services should be emphasized, and that genetic testing in this field should not be restricted to suspected childhood neuropsychiatric disorders. According to the neurodevelopmental hypothesis of SCZ, that suggests a brain development disruption in early life (due to genetic and early environmental factors), prompting to a subsequent later emergence of the disease in adulthood, even chronic complex adult mental illness, such as SCZ, deserves detailed investigations and a more exhaustive genetic evaluation.

Recently, a new form of autosomal recessive early-onset parkinsonism (PARK20), due to mutations in the gene encoding the phosphoinositide phosphatase, Synaptojanin 1 (Synj1), has been reported. Several genes responsible for hereditary forms of Parkinson’s disease are implicated in distinct steps of the endolysosomal pathway. However, the nature and the degree of endocytic membrane trafficking impairment in early-onset parkinsonism remains elusive. Here, we show that depletion of Synj1 causes drastic alterations of early endosomes, which become enlarged and more numerous, while it does not affect the morphology of late endosomes both in non-neuronal and neuronal cells. Moreover, Synj1 loss impairs the recycling of transferrin, while it does not alter the trafficking of the epidermal growth factor receptor. The ectopic expression of Synj1 restores the functions of early endosomes, and rescues these trafficking defects in depleted cells. Importantly, the same alterations of early endosomal compartments and trafficking defects occur in fibroblasts of PARK20 patients. Our data indicate that Synj1 plays a crucial role in regulating the homeostasis and functions of early endosomal compartments in different cell types, and highlight defective cellular pathways in PARK20. In addition, they strengthen the link between endosomal trafficking and Parkinson’s disease.

Trisomy of chromosome 21 (TS21) is the most common autosomal aneuploidy compatible with postnatal survival with a prevalence of 1 in 700 newborns. Its phenotype is highly complex with constant features, such as mental retardation, dysmorphic traits and hypotonia, and variable features including heart defects, susceptibility to Alzheimer’s disease (AD), type 2 diabetes, obesity and immune disorders. Overexpression of genes on chromosome-21 (Hsa21) is responsible for the pathogenesis of Down syndrome (DS) phenotypic features either in a direct or in an indirect manner since many Hsa21 genes can affect the expression of other genes mapping to different chromosomes. Many of these genes are involved in mitochondrial function and energy conversion, and play a central role in the mitochondrial dysfunction and chronic oxidative stress, consistently observed in DS subjects. Recent studies highlight the deep interconnections between mitochondrial dysfunction and DS phenotype. In this short review we first provide a basic overview of mitochondrial phenotype in DS cells and tissues. We then discuss how specific Hsa21 genes may be involved in determining the disruption of mitochondrial DS phenotype and biogenesis. Finally we briefly focus on drugs that affect mitochondrial function and mitochondrial network suggesting possible therapeutic approaches to improve and/or prevent some aspects of the DS phenotype.

Key Clinical Message A prenatal case presenting with congenital diaphragmatic hernia (CDH) and distal 16p11.2 microdeletion suggests two possible causative hypotheses: (1) a functional effect of chromatin loopings between the distal and the proximal 16p11.2 microdeletion traits, associated with CHD; (2) a possible role of ATP2A1, a deleted gene involved in diaphragm development.

Background SHANK3 mutations are responsible for Phelan-McDermid syndrome but they are also associated with autism and/or intellectual disability. Case report We report a family with four affected individuals including the 37 year-old mother, her 12 year-old male monozygotic twins and 8 year-old daughter harboring a novel SHANK3 interstitial microdeletion. All four members presented with intellectual disability of variable severity. The twins showed brain abnormalities similar to Unidentified Bright Objects (UBOs), typically detected in patients with Neurofibromatosis type 1 (NF1), but they did not display causative mutations in NF1 gene. Conclusion To date, this is the first report of an affected individual with SHANK3 interstitial deletion able to reproduce. Moreover, we found a previously unreported possible association between SHANK3 deletion and UBOs-like lesions in the brain.

Primrose syndrome is characterized by unusual facial features, macrocephaly, intellectual disability, enlarged, and calcified external ears, sparse body hair, and distal muscle wasting. Nine patients have been described in the literature. The disorder is due to missense mutations in ZBTB20. Here we describe one newly diagnosed 18-month-old patient and provide 10 year follow-up of an earlier reported patient, highlighting the progression and complexity of the disorder. Metabolic studies showed reduced glucose tolerance with prevalence of amino acids and fatty acids catabolism, ketogenesis, and gluconeogenesis, resulting in a Krebs cycle reversion.

Oral-Facial-Digital type I (OFD1) is a rare inherited form of renal cystic disease associated with ciliary dysfunction. This disorder is due to mutations in the OFD1 gene that encodes a protein localized to centrosomes and basal bodies in different cell types. Immunofluorescence analysis demonstrated that OFD1 displays a dynamic distribution during cell cycle. High-content microscopy analysis of Ofd1-depleted fibroblasts revealed impaired cell cycle progression. Immunofluorescence analysis and cell proliferation assays also indicated the presence of a variety of defects such as centrosome accumulation, nuclear abnormalities and aneuploidy. In addition, Ofd1-depleted cells displayed an abnormal microtubule network that may underlie these defects. All together our results suggest that OFD1 contributes to the function of the microtubule organizing center (MTOC) in the cell, controlling cell cycle progression both in vitro and in vivo.

PARK20, an early onset autosomal recessive parkinsonism is due to mutations in the phosphatidylinositol-phosphatase Synaptojanin 1 (Synj1). We have recently shown that the early endosomal compartments are profoundly altered in PARK20 fibroblasts as well as the endosomal trafficking. Here, we report that PARK20 fibroblasts also display a drastic alteration of the architecture and function of the early secretory compartments. Our results show that the exit machinery from the Endoplasmic Reticulum (ER) and the ER-to-Golgi trafficking are markedly compromised in patient cells. As a consequence, PARK20 fibroblasts accumulate large amounts of cargo proteins within the ER, leading to the induction of ER stress. Interestingly, this stressful state is coupled to the activation of the PERK/eIF2a/ATF4/CHOP pathway of the Unfolded Protein Response (UPR). In addition, PARK20 fibroblasts reveal upregulation of oxidative stress markers and total ROS production with concomitant alteration of the morphology of the mitochondrial network. Interestingly, treatment of PARK20 cells with GSK2606414 (GSK), a specific inhibitor of PERK activity, restores the level of ROS, signaling a direct correlation between ER stress and the induction of oxidative stress in the PARK20 cells. All together, these findings suggest that dysfunction of early secretory pathway might contribute to the pathogenesis of the disease.

Mitochondrial dysfunction plays a primary role in neurodevelopmental anomalies and neurodegeneration of Down syndrome (DS) subjects. For this reason, targeting mitochondrial key genes, such as PGC-1α/PPARGC1A, is emerging as a good therapeutic approach to attenuate cognitive disability in DS. After demonstrating the efficacy of the biguanide metformin (a PGC-1α activator) in a cell model of DS, we extended the study to other molecules that regulate the PGC-1α pathway acting on PPAR genes. We, therefore, treated trisomic fetal fibroblasts with different doses of pioglitazone (PGZ) and evaluated the effects on mitochondrial dynamics and function. Treatment with PGZ significantly increased mRNA and protein levels of PGC-1α. Mitochondrial network was fully restored by PGZ administration affecting the fission-fusion mitochondrial machinery. Specifically, optic atrophy 1 (OPA1) and mitofusin 1 (MFN1) were upregulated while dynamin-related protein 1 (DRP1) was downregulated. These effects, together with a significant increase of basal ATP content and oxygen consumption rate, and a significant decrease of reactive oxygen species (ROS) production, provide strong evidence of an overall improvement of mitochondria bioenergetics in trisomic cells. In conclusion, we demonstrate that PGZ is able to improve mitochondrial phenotype even at low concentrations (0.5 μM). We also speculate that a combination of drugs that target mitochondrial function might be advantageous, offering potentially higher efficacy and lower individual drug dosage.

We have carried out a retrospective study of chromosome anomalies associated with increased nuchal translucency (NT) in order to compare yield rates of karyotype, chromosome microarray analysis (CMA), and non-invasive prenatal testing (NIPT) in this condition. Presenting with increased NT or cystic hygroma &ge, 3.5 mm as an isolated sign, 249 fetuses underwent karyotype and/or CMA from 11 to 18 gestational weeks. Karyotype and fluorescence in situ hybridization (FISH) analyses detected 103 chromosomal anomalies including 95 aneuploidies and eight chromosomal rearrangements or derivatives. Further, seven pathogenic copy number variants (CNV), five likely pathogenic CNVs, and 15 variants of unknown significance (VOUS) were detected by CMA in fetuses with normal karyotype. Genetic testing is now facing new challenges due to results with uncertain clinical impacts. Additional investigations will be necessary to interpret these findings. More than 15% of the anomalies that we have diagnosed with invasive techniques could not be detected by NIPT. It is therefore definitely not recommended in the case of ultrasound anomalies. These results, while corroborating the use of CMA in fetuses with increased NT as a second tier after rapid aneuploidy testing, do not suggest a dismissal of karyotype analysis.

We identified a 14q21.2 microdeletion in a 16-year-old boy with autism spectrum disorder (ASD), IQ in the lower part of normal range but high-functioning memory skills. The deletion affects a gene desert, and the non-deletedgene closest to the microdeletion boundaries is LRFN5, which encodes a protein involved in synaptic plasticity and implicated in neuro-psychiatric disorders. LRFN5 expression was significantly decreased in the proband’s skin fibroblasts. The deleted region includes the pseudogene chr14.232.a, which is transcribed into a long non-coding RNA (lncLRFN5-10), whose levels were also significantly reduced in the proband’s fibroblasts compared to controls. Transfection of the patient’s fibroblasts with a plasmid expressing chr14.232.a significantly increased LRFN5 expression, while siRNA targeting chr14.232.a-derived lncLRFN5-10 reduced LRFN5 levels. In summary, we report on an individual with ASD carrying a microdeletion encompassing the pseudogene chr14.232.a encoding for lncLRFN5-10, which was found to affect the expression levels of the nearby, non-deleted LRFN5. This case illustrates the potential role of long non-coding RNAs in regulating expression of neighbouring genes with a functional role in ASD pathogenesis.

Cellular prion protein (PrPC) is a glycosyl-phosphatidyl-inositol (GPI) anchored glycoprotein whose precise function in the brain remains elusive but may depend upon its cellular localization. PrPC is able to misfold to a pathogenic isoform PrPSc, the causative agent of neurodegenerative prion diseases. The PrPSc formation and cellular propagation has been related to the presence of the PrP receptor 37/67 kDa LR (Laminin Receptor), as well as to a member of the prion protein family called Shadoo. The misfolded PrPSc is amyloidogenic and strictly related to expression, intracellular localization and association of PrPC itself to cholesterol enriched membrane microdomains (lipid rafts). In this report we show our recent findings related to: 1. The biological effects deriving from the treatment with specific 37/67 kDa LR inhibitor, NSC47924, on the trafficking and interaction between PrPC and its receptor 2. The natural tendency of Shadoo to acquire in neuronal cells “prion-like” characteristics, such as misfolding and aggregation state, and the existence of its non-translocated ER form, whose presence into mitochondria is controlled by the chaperone TRAP1. Altogether our findings contribute i) to reveal NSC47924 inhibitor as a useful tool to regulate PrPC and 37/67 kDa LR trafficking and degradation, representing a novel small molecule to be tested against prion diseases and ii) to understand the role of molecular chaperones and of PrP-related folding intermediates in “prion-like” conversion.

Homeostasis of eukaryotic cells is largely dependent on dynamic com-partmentalization of the endo-membrane system. The membrane traf-ficking linking different organelles is essential to maintain a proper composition of various compartments as well as to transport various molecules to appropriate compartments. Respect to other cell types nervous system is more sensitive to alterations of the membrane traf-ficking. In the last years, we studied the role of endosomal trafficking in neurodegeneration focusing on two nervous system disorders, Charcot-Marie Tooth disease 4 J (CMT4 J) and a new form of autosomal recessive early-onset parkinsonism (PARK20), both caused by muta-tions of an inositol phosphatase (Fig 4 and Synj1, respectively). Our recent investigations show that:1. Synj1 plays a crucial role in regulating the homeostasis and func-tions of early endosomal compartments in different cell types and in fibroblasts of PARK20 patients;2. the loss of Fig 4 drastically alters the whole endo-lysosome axis (lysosomes, but also late and early endosomes result enlarged and more numerous) implying its essential role for the homeostasis and function of these compartments.All together, our data provide evidence for the implication of endo-somal pathway in neurodegeneration, emphasising the link between endosomal trafficking and neurodegenerative diseases.

Rab7 regulates the biogenesis of late endosomes, lysosomes, and autophagosomes. It has been proposed that a functional and physical interaction exists between Rab7 and Rac1 GTPases in CDH1 endocytosis and ruffled border formation. In FRT cells over-expressing Rab7, increased expression and activity of Rac1 was observed, whereas a reduction of Rab7 expression by RNAi resulted in reduced Rac1 activity, as measured by PAK1 phosphorylation. We found that CDH1 endocytosis was extremely reduced only in Rab7 over-expressing cells but was unchanged in Rab7 silenced cells. In Rab7 under or over-expressing cells, Rab7 and LC3B-II co-localized and co-localization in large circular structures occurred only in Rab7 over-expressing cells. These large circular structures occurred in about 10% of the cell population; some of them (61%) showed co-localization of Rab7 with cortactin and f-actin and were identified as circular dorsal ruffles (CDRs), the others as mature autophagosomes. We propose that the over-expression of Rab7 is sufficient to induce CDRs. Furthermore, in FRT cells, we found that the expression of the insoluble/active form of Rab7, rather than Rab5, or Rab8, was inducible by cAMP and that cAMP-stimulated FRT cells showed increased PAK1 phosphorylation and were no longer able to endocytose CDH1. Finally, we demonstrated that Rab7 over-expressing cells are able to endocytose exogenous thyroglobulin via pinocytosis/CDRs more efficiently than control cells. We propose that the major thyroglobulin endocytosis described in thyroid autonomous adenomas due to Rab7 increased expression, occurs via CDRs. J. Cell. Physiol. 231: 1695-1708, 2016. © 2015 Wiley Periodicals, Inc.

Epithelial‑to‑mesenchymal transition (EMT) confers stem cell‑like phenotype and more motile properties to carcinoma cells. During EMT, the expression of E‑cadherin decreases, resulting in loss of cell‑cell adhesion and increased migration. Expression of Twist1 and other pleiotropic transcription factors, such as Snail, is known to activate EMT. We established primary colon cancer cell cultures from samples of operated patients and validated cultures by cytogenetic and molecular biology approaches. Western blot assay, quantitative real‑time PCR and immunofluorescence were performed to investigate the expression of E‑cadherin, vimentin, β‑catenin, cytokeratin‑20 and ‑18, Twist1, Snail, CD44, cyclooxygenase‑2 (COX2), Sox2, Oct4 and Nanog. Moreover, cell differentiation was induced by incubation with LiCl‑containing medium for 10 days. We observed that these primary colorectal cancer (CRC) cells lost expression of the E‑cadherin epithelial marker, which was instead expressed in cancer and normal colon mucosa of the same patient, while overexpressed vimentin (mesenchymal marker), Twist1, Snail (EMT markers) and COX2. Cytokeratin‑18 was expressed both in tissues and cell cultures. Expression of stem cell markers, such as CD44, Oct4 and Nanog, were also observed. Following differentiation with the glycogen synthase kinase 3β (GSK3β) inhibitor LiCl, the cells began to express E‑cadherin and, at once, Twist1 and Snail expression was strongly downregulated, suggesting a MET‑reverting process. In conclusion, we established primary colon mesenchymal cancer cell cultures expressing mesenchymal and epithelial biomarkers together with high level of EMT transcription factors. We propose that they could represent a good model for studying EMT and its reverting mechanism, the mesenchymal‑to‑epithelial transition (MET). Our observation indicates that LiCl, a GSK3β inhibitor, induces MET in vitro, suggesting that LiCl and GSK3β could represent, respectively, interesting drug, and target for CRC therapy.

Shadoo (Sho), a member of prion protein family, has been shown to prevent embryonic lethality in Prnp0/0 mice and to be reduced in the brains of rodents with terminal prion diseases. Sho can also affect PrP structural dynamics and can increase the prion conversion into its misfolded isoform (PrPSc), which is amyloidogenic and strictly related to expression, intracellular localization and association of PrPC to lipid rafts. We reasoned that if Sho possesses a natural tendency to convert to amyloid-like forms in vitro, it should be able to exhibit “prion-like” properties, such as PK-resistance and aggregation state, also in live cells. We tested this hypothesis, by different approaches in neuronal cells, finding that Sho shows folding properties partially dependent on lipid rafts integrity whose alteration, as well as proteasomal block, regulated generation of intermediate Sho isoforms and exacerbated its misfolding. Moreover, a 18 kDa isoform of Sho, likely bearing the signal peptide, was targeted to mitochondria by interacting with the molecular chaperone TRAP1 which, in turn controlled Sho dual targeting to ER or mitochondria. Our studies contribute to understand the role of molecular chaperones and of PrP-related folding intermediates in “prion-like” conversion.

Sensorineural hearing loss (SNHL) is a common defect with a multifactorial etiology. Congenital cytomegalovirus infection (cCMV) is the most common infectious cause, and its early detection allows a prompt pharmacological treatment that can improve hearing prognosis. In a consistent percentage of profound SNHL, genetic causes and/or inner ear malformations are involved; their prompt diagnosis might change therapeutic options. This study reports a case of a 3- year-old female patient with symptomatic cCMV infection who also exhibits developmental delay, dysmorphic facial features, bilateral hearing loss, and cochlear incomplete partition, type 2, in 7q21.3 deletion. This deletion includes the genes DLX5 and DLX6, which could be the candidate genes for the ear malformation named incomplete partition, type 2.

Dosage-dependent upregulation of most of chromosome 21 (Hsa21) genes has been demonstrated in heart tissues of fetuses with Down syndrome (DS). Also miRNAs might play important roles in the cardiac phenotype as they are highly expressed in the heart and regulate cardiac development. Five Hsa21 miRNAs have been well studied in the past: miR-99a-5p, miR-125b-2-5p, let-7c-5p, miR-155-5p, and miR-802-5p but few information is available about their expression in trisomic tissues. In this study, we evaluated the expression of these miRNAs in heart tissues from DS fetuses, showing that miR-99a-5p, miR-155-5p, and let-7c-5p were overexpressed in trisomic hearts. To investigate their role, predicted targets were obtained from different databases and cross-validated using the gene expression profiling dataset we previously generated for fetal hearts. Eighty-five targets of let-7c-5p, 33 of miR-155-5p, and 10 of miR-99a-5p were expressed in fetal heart and downregulated in trisomic hearts. As nuclear encoded mitochondrial genes were found downregulated in trisomic hearts and mitochondrial dysfunction is a hallmark of DS phenotypes, we put special attention to let-7c-5p and miR-155-5p targets downregulated in DS fetal hearts and involved in mitochondrial function. The let-7c-5p predicted targetSLC25A4/ANT1was identified as a possible candidate for both mitochondrial and cardiac anomalies.

Alterations in mitochondrial activity and morphology have been demonstrated in human cells and tissues from individuals with Down syndrome (DS), as well as in DS mouse models. An impaired activity of the transcriptional coactivator PGC-1α/PPARGC1A due to the overexpression of chromosome 21 genes, such as NRIP1/RIP140, has emerged as an underlying cause of mitochondrial dysfunction in DS. We tested the hypothesis that the activation of the PGC-1α pathway might indeed reverse this mitochondrial dysfunction. To this end, we investigated the effects of metformin, a PGC-1α-activating drug, on mitochondrial morphology and function in DS foetal fibroblasts. Metformin induced both the expression of PGC-1α and an augmentation of its activity, as demonstrated by the increased expression of target genes, strongly promoting mitochondrial biogenesis. Furthermore, metformin enhanced oxygen consumption, ATP production, and overall mitochondrial activity. Most interestingly, this treatment reversed the fragmentation of mitochondria observed in DS and induced the formation of a mitochondrial network with a branched and elongated tubular morphology. Concomitantly, cristae remodelling occurred and the alterations observed by electron microscopy were significantly reduced. We finally demonstrated that the expression of genes of the fission/fusion machinery, namely OPA1 and MFN2, was reduced in trisomic cells and increased by metformin treatment. These results indicate that metformin promotes the formation of a mitochondrial network and corrects the mitochondrial dysfunction in DS cells. We speculate that alterations in the mitochondrial dynamics can be relevant in the pathogenesis of DS and that metformin can efficiently counteract these alterations, thus exerting protective effects against DS-associated pathologies.

The 37/67 kDa laminin receptor (LR) is a non-integrin protein, which binds both laminin-1 of the extracellular matrix and prion proteins, that hold a central role in prion diseases. The 37/67 kDa LR has been identified as interactor for the prion protein (PrPC) and to be required for pathological PrP (PrPSc) propagation in scrapie-infected neuronal cells, leading to the possibility that 37/67 kDa LR-PrPC interaction is related to the pathogenesis of prion diseases. A relationship between 37/67 kDa LR and PrPC in the presence of specific LR inhibitor compounds has not been investigated yet. We have characterized the trafficking of 37/67 kDa LR in both neuronal and non-neuronal cells, finding the receptor on the cell surface and nuclei and identified the 67 kDa LR as the almost exclusive isoform interacting with PrPC. Here, we show that the treatment with the 37/67 kDa LR inhibitor, NSC47924, affects both the direct 37/67 kDa LR-PrPC interaction in vitro and the formation of the immunocomplex in live cells, inducing a progressive internalization of 37/67 kDa LR and stabilization of PrPC on the cell surface. These data reveal NSC47924 as a useful tool to regulate PrPC and 37/67 kDa LR trafficking and degradation, representing a novel small molecule to be tested against prion diseases.

Chromosome 22q11.2 deletion is the most common chromosomal alteration associated with DiGeorge syndrome (DGS), even though this is not the only underlying cause of DGS. In rare patients, mutations in a single gene, TBX1, have been described resulting in a DGS phenotype. Recently, it has been reported that at least part of the TBX1 mutant phenotype is due to excessive bone morphogenetic proteins (BMP) signaling. Evidence suggests that miRNA may modulate the expression of critical T-box transcriptional regulators during midface development and Bmp-signaling. We report on a 7-year-old Caucasian male born to a mother affected with gestational diabetes (GDM) who had a 371Kb-interstitial deletion of 3p12.3 identified by array CGH, involving the ZNF717, MIR1243 and 4273 genes. The child presented with a DiGeorge anomaly (DGA) associated with unilateral renal agenesis and language delay. The immunological evaluation revealed a severe reduction and impairment of T lymphocytes. FISH analysis and TBX1 sequencing were negative. Among the miRNA-4273 predicted target genes, we found BMP3, which is involved in several steps of embryogenesisincluding kidney and lung organogenesis and in insulin gene expression. Since DGA is not commonly found in newborns of diabetic mothers, we hypothesize that the pathogenesis of DGA associated with GDM is multifactorial, involving both genetic and/or epigenetic cofactors.

In childhood, several rare genetic diseases have overlapping symptoms and signs, including those regarding growth alterations, thus the differential diagnosis is sometimes difficult. The proband, aged 3 years, was suspected to have Silver–Russel syndrome because of intrauterine growth retardation, postnatal growth retardation, typical facial dysmorphic features, macrocephaly, body asymmetry, and bilateral fifth finger clinodactyly. Other features were left atrial and ventricular enlargement and patent foramen ovale. Total X-ray skeleton showed hypoplasia of the twelfth rib bilaterally and of the coccyx, slender long bones with thick cortex, and narrow medullary channels. The genetic investigation did not confirm Silver–Russel syndrome. At the age of 5 the patient developed an additional sign: hepatomegaly. Array CGH revealed a 147 kb deletion (involving TRIM 37 and SKA2 genes) on one allele of chromosome 17, inherited from his mother. These results suggested Mulibrey nanism. The clinical features were found to fit this hypothesis. Sequencing of the TRIM 37 gene showed a single base change at a splicing locus, inherited from his father that provoked a truncated protein. The combined use of Array CGH and DNA sequencing confirmed diagnosis of Mulibrey nanism. The large deletion involving the SKA2 gene, along with the increased frequency of malignant tumours in mulibrey patients, suggests closed monitoring for cancer of our patient and his mother. Array CGH should be performed as first tier test in all infants with multiple anomalies. The clinician should reconsider the clinical features when the genetics suggests this. © 2016 Wiley Periodicals, Inc.

Rab7 regulates the biogenesis of late endosomes, lysosomes, and autophagosomes. It has been proposed that a functional and physical interaction exists between Rab7 and Rac1 GTPases in CDH1 endocytosis and ruffled border formation. In FRT cells over-expressing Rab7, increased expression and activity of Rac1 was observed, whereas a reduction of Rab7 expression by RNAi resulted in reduced Rac1 activity, as measured by PAK1 phosphorylation. We found that CDH1 endocytosis was extremely reduced only in Rab7 over-expressing cells but was unchanged in Rab7 silenced cells. In Rab7 under or over-expressing cells, Rab7 and LC3B-II co-localized and co-localization in large circular structures occurred only in Rab7 over-expressing cells. These large circular structures occurred in about 10% of the cell population; some of them (61%) showed co-localization of Rab7 with cortactin and f-actin and were identified as circular dorsal ruffles (CDRs), the others as mature autophagosomes. We propose that the over-expression of Rab7 is sufficient to induce CDRs. Furthermore, in FRT cells, we found that the expression of the insoluble/active form of Rab7, rather than Rab5, or Rab8, was inducible by cAMP and that cAMP-stimulated FRT cells showed increased PAK1 phosphorylation and were no longer able to endocytose CDH1. Finally, we demonstrated that Rab7 over-expressing cells are able to endocytose exogenous thyroglobulin via pinocytosis/CDRs more efficiently than control cells. We propose that the major thyroglobulin endocytosis described in thyroid autonomous adenomas due to Rab7 increased expression, occurs via CDRs. J. Cell. Physiol. 231: 1695-1708, 2016. © 2015 Wiley Periodicals, Inc.

Trisomy of chromosome 21 is associated to congenital heart defects in ∼50% of affected newborns. Transcriptome analysis of hearts from trisomic human foeti demonstrated that genes involved in mitochondrial function are globally downregulated with respect to controls, suggesting an impairment of mitochondrial function. We investigated here the properties of mitochondria in fibroblasts from trisomic foeti with and without cardiac defects. Together with the upregulation of Hsa21 genes and the downregulation of nuclear encoded mitochondrial genes, an abnormal mitochondrial cristae morphology was observed in trisomic samples. Furthermore, impairment of mitochondrial respiratory activity, specific inhibition of complex I, enhanced reactive oxygen species production and increased levels of intra-mitochondrial calcium were demonstrated. Seemingly, mitochondrial dysfunction was more severe in fibroblasts from cardiopathic trisomic foeti that presented a more pronounced pro-oxidative state. The data suggest that an altered bioenergetic background in trisomy 21 foeti might be among the factors responsible for a more severe phenotype. Since the mitochondrial functional alterations might be rescued following pharmacological treatments, these results are of interest in the light of potential therapeutic interventions.

We report on a child with a de novo deletion of approximately 12 Mb detected through array comparative genomic hybridization (CGH). The deletion involved chromosome bands 13q12.3 to 13q14.11 and determined the loss of ≥ 50 genes. A second deletion on chromosome 12p11.3p11.22 of 43-167 kb, including about 12 genes, was unlikely of clinical relevance because inherited from the asymptomatic father. The child had developmental delay, dysmorphisms and many features reminiscent of ataxia-telangiectasia (A-T), as cerebellar ataxia, oculocutaneus telangiectasia and recurrent upper airway infections. Atraumatic fractures of the metatarsus were noted. Moreover, this is a rare case of 13q deletion syndrome associated with peripheral blood white cells radiosensitivity to bleomycin, reminiscent of what previously reported on X-ray hypersensitivity of fibroblasts from patients with alterations of this chromosome. The immunological evaluation revealed increased IgM serum levels and a low proliferative response to mitogens, PHA and CD3 cross-linking (CD3 XL). After 12 years of age only a mild dysmetria persisted, while the proliferative response to mitogens became normal by 9 years of age.

Objective We previously reported on the validation of Prenatal BACs-on-Beads TM on retrospectively selected and prospective prenatal samples. This bead-based multiplex assay detects chromosome 13, 18, 21 and X/Y aneuploidies and the nine most frequent microdeletion syndromes. We demonstrated that Prenatal BACs-on-Beads TM is a newgeneration, prenatal screening tool. Here, we describe the experience of five European prenatal diagnosis laboratories concerning the ongoing use of Prenatal BACs-on-Beads TM . Methods Some 1653 samples were analyzed. All results were confirmed by conventional karyotyping or another appropriate technique. All indications for invasive prenatal diagnosis were included. Amniotic fluid and chorionic villus samples were analyzed in equivalent proportions. Results The failure rate was 3.3% and the overall abnormality detection rate was ~1/10. Eighty-five percent of the detected abnormalities were common aneuploidies. Eleven microdeletions and duplications were identified, thus giving an overall yield for microdeletion and microduplication detection of 1/145. Compared with QF-PCR, Prenatal BACs-on-Beads TM provides an additional detection rate of ~1/250 for low-risk pregnancies. The false positive and negative rates were both

Small supernumerary marker chromosomes (sSMC) occur with a frequency of approximately 0.4 per 1000 newborns and are more frequent in the population with mental retardation and/or with dysmorphic signs. Small supernumerary chromosome rings (sSCR) usually occur as apart of a mosaic karyotype (Liehr et al., 2004). Chromosome 19 supernumerary rings are very rare. Almost all cases of sSMC19 have been reported on Thomas Liehr's website (http://www.med.uni-jena.de/fish/sSMC/19.htm#Start19). Of these cases, 14 were with phenotypic abnormalities and a clear characterization of the sSMC; two cases were suitable for comparison with our case with regard to their genetic content, but not with regard to the structure ofthe sSMC (Manvelyan et al., 2008). The phenotype, associated with partial trisomy 19q, includes facial dysmorphism, growth and mental retardation, macrocephaly, heart malformation and anomalies of the genitourinary and gastrointestinal tracts. The phenotype associated with partial trisomy 19p is characterized by dysmorphic features, severe mental retardation, abnormalities of brain morphology and anomalies of the fingers (Tercanli et al., 2000; Qorri et al., 2002; Novelli et al., 2005; Vraneković et al., 2008). Herein, we report the phenotype and molecular cytogenetic analysis in a patient with the smallest de-novo constitutional ring extended from the p12 to q12 region of chromosome 19.