Generation of induced pluripotent stem cells (CSSi017-A)(12862) from an ALS patient carrying a repeat expansion in the C9orf72 gene

Genetic expansions of the hexanucleotide repeats (GGGGCC) in the C9orf72 gene appear in approximately 40% of patients with familial ALS and 7% of patients with sporadic ALS in the European population, making this mutation one of the most prevalent genetic mutations in ALS. Here, we generated a human induced pluripotent stem cell (hiPSC) line from the dermal fibroblasts of a patient carrying a 56-repeat expansion in an ALS disease-causing allele of C9orf72. These iPSCs showed stable amplification in vitro with normal karyotype and high expression of pluripotent markers and differentiated spontaneously in vivo into three germ layers.

Metabolic Profile of Patients with Smith-Magenis Syndrome: An Observational Study with Literature Review

Background: Smith-Magenis syndrome (SMS) is caused by either interstitial deletions in the 17p11.2 region or pathogenic variants in the RAI1 gene and is marked by a distinct set of physical, developmental, neurological, and behavioral features. Hypercholesterolemia has been described in SMS, and obesity is also commonly found. Aim: To describe and characterize the metabolic phenotype of a cohort of SMS patients with an age range of 2.9-32.4 years and to evaluate any correlations between their body mass index and serum lipids, glycated hemoglobin (HbA1c), and basal insulin levels. Results: Seven/thirty-five patients had high values of both total cholesterol and low-density lipoprotein cholesterol; 3/35 had high values of triglycerides; none of the patients with RAI1 variants presented dyslipidemia. No patients had abnormal fasting glucose levels. Three/thirty-five patients had HbA1c in the prediabetes range. Ten/twenty-two patients with 17p11.2 deletion and 2/3 with RAI1 variants had increased insulin basal levels. Three/twenty-three patients with the 17p11.2 deletion had prediabetes. Conclusion: Our investigation suggests that SMS 'deleted' patients may show a dyslipidemic pattern, while SMS 'mutated' patients are more likely to develop early-onset obesity along with hyperinsulinism.

Generation of an induced pluripotent stem cell line CSSi015-A (9553), carrying a point mutation c.2915C > T in the human calcium sensing receptor (CasR) gene

Familial Hypocalciuric Hypercalcemia (FHH1) is a rare autosomal dominant disease with low penetrance, caused by inactivating mutations of the calcium-sensing receptor (CaSR) gene, characterized by significant hypercalcemia, inappropriately normal serum PTH levels and a low urinary calcium level. Human induced pluripotent stem cells (hiPSCs) from a patient carrying a previously identified heterozygous mutation, a p.T972M amino acid substitution in cytoplasmic tail of CasR, were produced using a virus, xeno-free and non-integrative protocol.

Circadian profile, daytime activity, and the Parkinson's phenotype: A motion sensor pilot study with neurobiological underpinnings

Circadian rhythm impairment may play a role in Parkinson's disease (PD) pathophysiology. Recent literature associated circadian rhythm features to the risk of developing Parkinson and to its progression through stages. The association between the chronotype and the phenotype should be verified on a clinical and biological point of view. Herein we investigate the chronotype of a sample of 50 PD patients with the Morningness Eveningness Questionnaire and monitor their daily activity with a motion sensor embedded in a smartphone. Fibroblasts were collected from PD patients (n = 5) and from sex/age matched controls (n = 3) and tested for the circadian expression of clock genes (CLOCK, BMAL1, PER1, CRY1), and for cell morphology, proliferation, and death. Our results show an association between the chronotype and the PD phenotype. The most representative clinical chronotypes were "moderate morning" (56%), the "intermediate" (24%) and, in a minor part, the "definite morning" (16%). They differed for axial motor impairment, presence of motor fluctuations and quality of life (p < 0.05). Patients with visuospatial dysfunction and patients with a higher PIGD score had a blunted motor daily activity (p = 0.006 and p = 0.001, respectively), independently by the influence of age and other motor scores. Fibroblasts obtained by PD patients (n = 5) had an impaired BMAL1 cycle compared to controls (n = 3, p = 0.01). Moreover, a PD flat BMAL1 profile was associated with the lowest cell proliferation and the largest cell morphology. This study contributes to the growing literature on CR abnormalities in the pathophysiology of Parkinson's disease providing a link between the clinical and biological patient chronotype and the disease phenomenology.

Corrigendum: Deepening the understanding of CNVs on chromosome 15q11-13 by using hiPSCs: An overview

[This corrects the article DOI: 10.3389/fcell.2022.1107881.].

Deepening the understanding of CNVs on chromosome 15q11-13 by using hiPSCs: An overview

The human α7 neuronal nicotinic acetylcholine receptor gene (CHRNA7) is widely expressed in the central and peripheral nervous systems. This receptor is implicated in both brain development and adult neurogenesis thanks to its ability to mediate acetylcholine stimulus (Ach). Copy number variations (CNVs) of CHRNA7 gene have been identified in humans and are genetically linked to cognitive impairments associated with multiple disorders, including schizophrenia, bipolar disorder, epilepsy, Alzheimer's disease, and others. Currently, α7 receptor analysis has been commonly performed in animal models due to the impossibility of direct investigation of the living human brain. But the use of model systems has shown that there are very large differences between humans and mice when researchers must study the CNVs and, in particular, the CNV of chromosome 15q13.3 where the CHRNA7 gene is present. In fact, human beings present genomic alterations as well as the presence of genes of recent origin that are not present in other model systems as well as they show a very heterogeneous symptomatology that is associated with both their genetic background and the environment where they live. To date, the induced pluripotent stem cells, obtained from patients carrying CNV in CHRNA7 gene, are a good in vitro model for studying the association of the α7 receptor to human diseases. In this review, we will outline the current state of hiPSCs technology applications in neurological diseases caused by CNVs in CHRNA7 gene. Furthermore, we will discuss some weaknesses that emerge from the overall analysis of the published articles.

Generation and characterization of CSSi016-A (9938) human pluripotent stem cell line carrying two biallelic variants in MTMR5/SBF1 gene resulting in a case of severe CMT4B3

Charcot-Marie-Tooth type 4B3 (CMT4B3) is a rare subtype of hereditary neuropathy associated with variants in the MTMR5/SBF1 gene. Herein, we report the generation and characterization of a hiPSC line from a 12-year-old Italian girl with early onset severe polyneuropathy with motor and axonal involvement, harboring biallelic variants in the MTMR5/SBF1 gene. Fibroblasts were reprogrammed using non-integrating episomal plasmids, and iPSCs successfully passed the stemness and pluripotency tests. Patient-specific hiPSCs were produced to obtain a disease model for the study of this rare condition.

Production of CSSi013-A (9360) iPSC line from an asymptomatic subject carrying an heterozygous mutation in TDP-43 protein

Amyotrophic Lateral Sclerosis (ALS) is a fatal disease affecting both upper and lower motoneurons. The transactive response DNA binding protein (TARDBP) gene, encoding for TDP-43, is one of the most commonly mutated gene associated with familial cases of ALS (10%). We generated a human induced pluripotent stem cell (hiPSC) line from the fibroblasts of an asymptomatic subject carrying the TARDBP p.G376D mutation. This mutation is very rare and was described in a large Apulian family, in which all ALS affected members are carriers of the mutation. The subject here described is the first identified asymptomatic carrier of the mutation.

Characterization of the p.L145F and p.S135N Mutations in SOD1: Impact on the Metabolism of Fibroblasts Derived from Amyotrophic Lateral Sclerosis Patients

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of the upper and lower motor neurons (MNs). About 10% of patients have a family history (familial, fALS); however, most patients seem to develop the sporadic form of the disease (sALS). SOD1 (Cu/Zn superoxide dismutase-1) is the first studied gene among the ones related to ALS. Mutant SOD1 can adopt multiple misfolded conformation, lose the correct coordination of metal binding, decrease structural stability, and form aggregates. For all these reasons, it is complicated to characterize the conformational alterations of the ALS-associated mutant SOD1, and how they relate to toxicity. In this work, we performed a multilayered study on fibroblasts derived from two ALS patients, namely SOD1^L145F and SOD1^S135N, carrying the p.L145F and the p.S135N missense variants, respectively. The patients showed diverse symptoms and disease progression in accordance with our bioinformatic analysis, which predicted the different effects of the two mutations in terms of protein structure. Interestingly, both mutations had an effect on the fibroblast energy metabolisms. However, while the SOD1^L145F fibroblasts still relied more on oxidative phosphorylation, the SOD1^S135N fibroblasts showed a metabolic shift toward glycolysis. Our study suggests that SOD1 mutations might lead to alterations in the energy metabolism.

Smith Magenis syndrome: First case of congenital heart defect in a patient with Rai1 mutation

Smith Magenis syndrome (SMS) is a rare neurobehavioral disorder caused by 17p11.2 microdeletion encompassing Retinoic Acid-Induced 1 (RAI1) gene (90% of cases) or by RAI1 point mutation (10% of cases). The neuropsychological phenotype of individuals with 17p11.2 deletion and in those with RAI1 variants mostly overlaps. However, cardiac defects have been described only in patients with a deletion so far. Here, we present the first case of a patient affected by SMS caused by RAI1 variant in whom a severe congenital pulmonary valve stenosis was diagnosed at birth, requiring trans catheter dilatation in the first month of life. This case expands the phenotypic spectrum associated with RAI1 variants in SMS, describing a previously unreported association with a congenital heart disease.

COVID-19 Specific Immune Markers Revealed by Single Cell Phenotypic Profiling

COVID-19 is a viral infection, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and characterized by a complex inflammatory process and clinical immunophenotypes. Nowadays, several alterations of immune response within the respiratory tracts as well as at the level of the peripheral blood have been well documented. Nonetheless, their effects on COVID-19-related cell heterogeneity and disease progression are less defined. Here, we performed a single-cell RNA sequencing of about 400 transcripts relevant to immune cell function including surface markers, in mononuclear cells (PBMCs) from the peripheral blood of 50 subjects, infected with SARS-CoV-2 at the diagnosis and 27 healthy blood donors as control. We found that patients with COVID-19 exhibited an increase in COVID-specific surface markers in different subsets of immune cell composition. Interestingly, the expression of cell receptors, such as IFNGR1 and CXCR4, was reduced in response to the viral infection and associated with the inhibition of the related signaling pathways and immune functions. These results highlight novel immunoreceptors, selectively expressed in COVID-19 patients, which affect the immune functionality and are correlated with clinical outcomes.

Known Drugs Identified by Structure-Based Virtual Screening Are Able to Bind Sigma-1 Receptor and Increase Growth of Huntington Disease Patient-Derived Cells

Huntington disease (HD) is a devastating and presently untreatable neurodegenerative disease characterized by progressively disabling motor and mental manifestations. The sigma-1 receptor (σ1R) is a protein expressed in the central nervous system, whose 3D structure has been recently determined by X-ray crystallography and whose agonists have been shown to have neuroprotective activity in neurodegenerative diseases. To identify therapeutic agents against HD, we have implemented a drug repositioning strategy consisting of: (i) Prediction of the ability of the FDA-approved drugs publicly available through the ZINC database to interact with σ1R by virtual screening, followed by computational docking and visual examination of the 20 highest scoring drugs; and (ii) Assessment of the ability of the six drugs selected by computational analyses to directly bind purified σ1R in vitro by Surface Plasmon Resonance and improve the growth of fibroblasts obtained from HD patients, which is significantly impaired with respect to control cells. All six of the selected drugs proved able to directly bind purified σ1R in vitro and improve the growth of HD cells from both or one HD patient. These results support the validity of the drug repositioning procedure implemented herein for the identification of new therapeutic tools against HD.

Common atrium/atrioventricular canal defect and postaxial polydactyly: A mild clinical subtype of Ellis-van Creveld syndrome caused by hypomorphic mutations in the EVC gene

Clinical expression of Ellis-van Creveld syndrome (EvC) is variable and mild phenotypes have been described, including patients with mostly cardiac and limb involvement. Whether these cases are part of the EvC phenotypic spectrum or separate conditions is disputed. Herein, we describe a family with vertical transmission of atrioventricular canal defect (AVCD), common atrium, and postaxial polydactyly. Targeted sequencing of EVC, EVC2, WDR35, DYNC2LI1, and DYNC2H1 identified different compound heterozygosity in EVC genotypes in the two affected members, consisting of a nonsense (p.Arg622Ter) and a missense (p.Arg663Pro) variant in the father, and the same nonsense variant and a noncanonical splice-site in-frame change (c.1316-7A>G) in the daughter. Complementary DNA sequencing, immunoblot, and immunofluorescence experiments using patient-derived fibroblasts and Evc^-/- mouse embryonic fibroblasts showed that p.Arg622Ter is a loss-of-function mutation, whereas p.Arg663Pro and the splice-site change c.1316-7A>G are hypomorphic variants resulting in proteins that retain, in part, the ability to complex with EVC2. Our molecular and functional data demonstrate that at least in some cases the condition characterized as "common atrium/AVCD with postaxial polydactyly" is a mild form of EvC due to hypomorphic EVC mutations, further supporting the occurrence of genotype-phenotype correlations in this syndrome.

Generation of an induced pluripotent stem cell line, CSSi011-A (6534), from an Amyotrophic lateral sclerosis patient with heterozygous L145F mutation in SOD1 gene

Among the known causative genes of familial ALS, SOD1mutation is one of the most common. It encodes for the ubiquitous detoxifying copper/zinc binding SOD1 enzyme, whose mutations selectively cause motor neuron death, although the mechanisms are not as yet clear. What is known is that mutant-mediated toxicity is not caused by loss of its detoxifying activity but by a gain-of-function. In order to better understand the pathogenic mechanisms of SOD1 mutation, a human induced pluripotent stem cell (hiPSC) line was generated from the somatic cells of a female patient carrying a missense variation in SOD1 (L145F).

A Link between Genetic Disorders and Cellular Impairment, Using Human Induced Pluripotent Stem Cells to Reveal the Functional Consequences of Copy Number Variations in the Central Nervous System-A Close Look at Chromosome 15

Recent cutting-edge human genetics technology has allowed us to identify copy number variations (CNVs) and has provided new insights for understanding causative mechanisms of human diseases. A growing number of studies show that CNVs could be associated with physiological mechanisms linked to evolutionary trigger, as well as to the pathogenesis of various diseases, including cancer, autoimmune disease and mental disorders such as autism spectrum disorders, schizophrenia, intellectual disabilities or attention-deficit/hyperactivity disorder. Their incomplete penetrance and variable expressivity make diagnosis difficult and hinder comprehension of the mechanistic bases of these disorders. Additional elements such as co-presence of other CNVs, genomic background and environmental factors are involved in determining the final phenotype associated with a CNV. Genetically engineered animal models are helpful tools for understanding the behavioral consequences of CNVs. However, the genetic background and the biology of these animal model systems have sometimes led to confusing results. New cellular models obtained through somatic cellular reprogramming technology that produce induced pluripotent stem cells (iPSCs) from human subjects are being used to explore the mechanisms involved in the pathogenic consequences of CNVs. Considering the vast quantity of CNVs found in the human genome, we intend to focus on reviewing the current literature on the use of iPSCs carrying CNVs on chromosome 15, highlighting advantages and limits of this system with respect to mouse model systems.

A Multi-Layered Study on Harmonic Oscillations in Mammalian Genomics and Proteomics

Cellular, organ, and whole animal physiology show temporal variation predominantly featuring 24-h (circadian) periodicity. Time-course mRNA gene expression profiling in mouse liver showed two subsets of genes oscillating at the second (12-h) and third (8-h) harmonic of the prime (24-h) frequency. The aim of our study was to identify specific genomic, proteomic, and functional properties of ultradian and circadian subsets. We found hallmarks of the three oscillating gene subsets, including different (i) functional annotation, (ii) proteomic and electrochemical features, and (iii) transcription factor binding motifs in upstream regions of 8-h and 12-h oscillating genes that seemingly allow the link of the ultradian gene sets to a known circadian network. Our multifaceted bioinformatics analysis of circadian and ultradian genes suggests that the different rhythmicity of gene expression impacts physiological outcomes and may be related to transcriptional, translational and post-translational dynamics, as well as to phylogenetic and evolutionary components.

Generation of induced pluripotent stem cell line CSSi008-A (4698) from a patient affected by advanced stage of Dentato-Rubral-Pallidoluysian atrophy (DRPLA)

Dentato-Rubral-pallidoluysian atrophy (DRPLA) is a rare autosomal, dominant, progressive neurodegenerative disease that causes involuntary movements, mental and emotional problems. DRPLA is caused by a mutation in the ATN1 gene that encodes for an abnormal polyglutamine stretch in the atrophin-1 protein. DRPLA is most common in the Japanese population, where it has an estimated incidence of 2 to 7 per million people. This condition has also been seen in families from North America and Europe. We obtained a reprogrammed iPSC line from a Caucasian patient with a juvenile onset of the disease, carrying 64 CAG repeat expansion in the ATN1 gene.

Parkin Mutation Affects Clock Gene-Dependent Energy Metabolism

Growing evidence highlights a tight connection between circadian rhythms, molecular clockworks, and mitochondrial function. In particular, mitochondrial quality control and bioenergetics have been proven to undergo circadian oscillations driven by core clock genes. Parkinson’s disease (PD) is a chronic neurodegenerative disease characterized by a selective loss of dopaminergic neurons. Almost half of the autosomal recessive forms of juvenile parkinsonism have been associated with mutations in the PARK2 gene coding for parkin, shown to be involved in mitophagy-mediated mitochondrial quality control. The aim of this study was to investigate, in fibroblasts from genetic PD patients carrying parkin mutations, the interplay between mitochondrial bioenergetics and the cell autonomous circadian clock. Using two different in vitro synchronization protocols, we demonstrated that normal fibroblasts displayed rhythmic oscillations of both mitochondrial respiration and glycolytic activity. Conversely, in fibroblasts obtained from PD patients, a severe damping of the bioenergetic oscillatory patterns was observed. Analysis of the core clock genes showed deregulation of their expression patterns in PD fibroblasts, which was confirmed in induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs) derived thereof. The results from this study support a reciprocal interplay between the clockwork machinery and mitochondrial energy metabolism, point to a parkin-dependent mechanism of regulation, and unveil a hitherto unappreciated level of complexity in the pathophysiology of PD and eventually other neurodegenerative diseases.

Transplantation of clinical-grade human neural stem cells reduces neuroinflammation, prolongs survival and delays disease progression in the SOD1 rats

Stem cells are emerging as a therapeutic option for incurable diseases, such as Amyotrophic Lateral Sclerosis (ALS). However, critical issues are related to their origin as well as to the need to deepen our knowledge of the therapeutic actions exerted by these cells. Here, we investigate the therapeutic potential of clinical-grade human neural stem cells (hNSCs) that have been successfully used in a recently concluded phase I clinical trial for ALS patients (NCT01640067). The hNSCs were transplanted bilaterally into the anterior horns of the lumbar spinal cord (four grafts each, segments L3–L4) of superoxide dismutase 1 G93A transgenic rats (SOD1 rats) at the symptomatic stage. Controls included untreated SOD1 rats (CTRL) and those treated with HBSS (HBSS). Motor symptoms and histological hallmarks of the disease were evaluated at three progressive time points: 15 and 40 days after transplant (DAT), and end stage. Animals were treated by transient immunosuppression (for 15 days, starting at time of transplantation). Under these conditions, hNSCs integrated extensively within the cord, differentiated into neural phenotypes and migrated rostro-caudally, up to 3.77 ± 0.63 cm from the injection site. The transplanted cells delayed decreases in body weight and deterioration of motor performance in the SOD1 rats. At 40DAT, the anterior horns at L3–L4 revealed a higher density of motoneurons and fewer activated astroglial and microglial cells. Accordingly, the overall survival of transplanted rats was significantly enhanced with no rejection of hNSCs observed. We demonstrated that the beneficial effects observed after stem cell transplantation arises from multiple events that counteract several aspects of the disease, a crucial feature for multifactorial diseases, such as ALS. The combination of therapeutic approaches that target different pathogenic mechanisms of the disorder, including pharmacology, molecular therapy and cell transplantation, will increase the chances of a clinically successful therapy for ALS.

DP71 and SERCA2 alteration in human neurons of a Duchenne muscular dystrophy patient

Cognitive deficit has been identified in one third of patients affected by Duchenne Muscular Dystrophy, primarily attributed to loss of the short Dp71 dystrophin, the major brain dystrophin isoform. In this study, we investigated for the first time the Dp71 and Dp71-associated proteins cellular localization and expression in human neurons obtained by differentiation from induced pluripotent stem cell line of a patient affected by cognitive impairment. We found structural and molecular alterations in both pluripotent stem cell and derived neurons, reduced Dp71 expression, and a Ca²⁺ cytoplasmic overload in neurons coupled with increased expression of the SERCA2 pump in the dystrophic neurons. These results suggest that the reduction of Dp71 protein in the Duchenne muscular dystrophy neurons leads to alterations in SERCA2 and to elevated cytosolic Ca²⁺ concentration with consequent potential disruption of the dystrophin proteins and Dp71-associated proteins.

Establishment of stable iPS-derived human neural stem cell lines suitable for cell therapies

Establishing specific cell lineages from human induced pluripotent stem cells (hiPSCs) is vital for cell therapy approaches in regenerative medicine, particularly for neurodegenerative disorders. While neural precursors have been induced from hiPSCs, the establishment of hiPSC-derived human neural stem cells (hiNSCs), with characteristics that match foetal hNSCs and abide by cGMP standards, thus allowing clinical applications, has not been described. We generated hiNSCs by a virus-free technique, whose properties recapitulate those of the clinical-grade hNSCs successfully used in an Amyotrophic Lateral Sclerosis (ALS) phase I clinical trial. Ex vivo, hiNSCs critically depend on exogenous mitogens for stable self-renewal and amplification and spontaneously differentiate into astrocytes, oligodendrocytes and neurons upon their removal. In the brain of immunodeficient mice, hiNSCs engraft and differentiate into neurons and glia, without tumour formation. These findings now warrant the establishment of clinical-grade, autologous and continuous hiNSC lines for clinical trials in neurological diseases such as Huntington’s, Parkinson’s and Alzheimer’s, among others.

Reciprocal Interactions of Mitochondria and the Neuroimmunoendocrine System in Neurodegenerative Disorders: An Important Role for Melatonin Regulation

Structural and functional alterations of mitochondria are intimately linked to a wide array of medical conditions. Many factors are involved in the regulation of mitochondrial function, including cytokines, chaperones, chemokines, neurosteroids, and ubiquitins. The role of diffusely located cells of the neuroendocrine system, including biogenic amines and peptide hormones, in the management of mitochondrial function, as well as the role of altered mitochondrial function in the regulation of these cells and system, is an area of intense investigation. The current article looks at the interactions among the cells of the neuronal-glia, immune and endocrine systems, namely the diffuse neuroimmunoendocrine system (DNIES), and how DNIES interacts with mitochondrial function. Whilst changes in DNIES can impact on mitochondrial function, local, and systemic alterations in mitochondrial function can alter the component systems of DNIES and their interactions. This has etiological, course, and treatment implications for a wide range of medical conditions, including neurodegenerative disorders. Available data on the role of melatonin in these interactions, at cellular and system levels, are reviewed, with directions for future research indicated.

Production and characterization of CSSI003 (2961) human induced pluripotent stem cells (iPSCs) carrying a novel puntiform mutation in RAI1 gene, Causative of Smith-Magenis syndrome

Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by developmental delay, behavioural problems and circadian rhythm dysregulation. About 90% of SMS cases are due to a 17p11.2 deletion containing retinoic acid induced1 (RAI1) gene, 10% are due to heterozygous mutations affecting RAI1 coding region. Little is known about RAI1 role.

Generation of induced pluripotent stem cell line, CSSi004-A (2962), from a patient diagnosed with Huntington's disease at the presymptomatic stage

Huntington's disease (HD) is an incurable, autosomal dominant, hereditary neurodegenerative disorder that typically manifests itself in midlife. This pathology is linked to the deregulation of multiple, as yet unknown, cellular processes starting before HD onset. A human iPS cell line was generated from skin fibroblasts of a subject at the presymptomatic life stage, carrying a polyglutamine expansion in HTT gene codifying Huntingtin protein. The iPSC line contained the expected CAG expansion, expressed the expected pluripotency markers, displayed in vivo differentiation potential to the three germ layers and had a normal karyotype.

Production and characterization of human induced pluripotent stem cells (iPSCs) from Joubert Syndrome: CSSi001-A (2850)

Joubert Syndrome (JS) is a rare autosomal recessive or X-linked condition characterized by a peculiar cerebellar malformation, known as the molar tooth sign (MTS), associated with other neurological phenotypes and multiorgan involvement. JS is a ciliopathy, a spectrum of disorders whose causative genes encode proteins involved in the primary cilium apparatus. In order to elucidate ciliopathy-associated molecular mechanisms, human induced pluripotent stem cells (hiPSCs) were derived from a patient affected by JS carrying a homozygous missense mutation in the AHI1 gene (p.H896R) that encodes a protein named Jouberin.

Generation of induced pluripotent stem cell line, CSSi002-A (2851), from a patient with juvenile Huntington Disease

Huntington Disease (HD) is an autosomal dominant disorder characterized by motor, cognitive and behavioral features caused by a CAG expansion in the HTT gene beyond 35 repeats. The juvenile form (JHD) may begin before the age of 20years and is associated with expanded alleles as long as 60 or more CAG repeats. In this study, induced pluripotent stem cells were generated from skin fibroblasts of a 8-year-old child carrying a large size mutation of 84 CAG repeats in the HTT gene. HD appeared at age 3 with mixed psychiatric (i.e. autistic spectrum disorder) and motor (i.e. dystonia) manifestations.

Hypomorphic Recessive Variants in SUFU Impair the Sonic Hedgehog Pathway and Cause Joubert Syndrome with Cranio-facial and Skeletal Defects

The Sonic Hedgehog (SHH) pathway is a key signaling pathway orchestrating embryonic development, mainly of the CNS and limbs. In vertebrates, SHH signaling is mediated by the primary cilium, and genetic defects affecting either SHH pathway members or ciliary proteins cause a spectrum of developmental disorders. SUFU is the main negative regulator of the SHH pathway and is essential during development. Indeed, Sufu knock-out is lethal in mice, and recessive pathogenic variants of this gene have never been reported in humans. Through whole-exome sequencing in subjects with Joubert syndrome, we identified four children from two unrelated families carrying homozygous missense variants in SUFU. The children presented congenital ataxia and cerebellar vermis hypoplasia with elongated superior cerebellar peduncles (mild "molar tooth sign"), typical cranio-facial dysmorphisms (hypertelorism, depressed nasal bridge, frontal bossing), and postaxial polydactyly. Two siblings also showed polymicrogyria. Molecular dynamics simulation predicted random movements of the mutated residues, with loss of the native enveloping movement of the binding site around its ligand GLI3. Functional studies on cellular models and fibroblasts showed that both variants significantly reduced SUFU stability and its capacity to bind GLI3 and promote its cleavage into the repressor form GLI3R. In turn, this impaired SUFU-mediated repression of the SHH pathway, as shown by altered expression levels of several target genes. We demonstrate that germline hypomorphic variants of SUFU cause deregulation of SHH signaling, resulting in recessive developmental defects of the CNS and limbs which share features with both SHH-related disorders and ciliopathies.

Alpha-7 Nicotinic Receptors in Nervous System Disorders: From Function to Therapeutic Perspectives

BACKGROUND

The α7 nicotinic receptor consists of identical subunits and is one of the most abundant acetylcholine receptors in the mammalian central nervous system. However its expression is also found in the peripheral nervous system as well as in the immune system and various peripheral tissues. Nicotinic Receptors: They are involved in the regulation of several activities ranging from excitatory neurotransmission, the modulation of the release of several neurotransmitters, regulation of neurite outgrowth, and even neuronal survival/death. Its expression is found in brain areas that underlie learning and memory, suggesting their involvement in regulating cognitive functions. The α7-nicotinic receptor has a strategic role during development in regulating molecular pathways activated during neurogenesis. Because of its pleiotropic effects, receptor dysfunction or dysregulated expression is found in pathophysiological conditions of the nervous system including neurodegenerative diseases and neurodevelopmental disorders.

CONCLUSION

Here we review the physiological and pathological roles of alpha-7 nicotinic receptor in different nervous system disorders and the current therapeutic strategies developed to target selectively this receptor for potentiating or reducing its functions.

Stem cells from human amniotic fluid exert immunoregulatory function via secreted indoleamine 2,3-dioxygenase1

Although human amniotic fluid does contain different populations of foetal-derived stem cells, scanty information is available on the stemness and the potential immunomodulatory activity of in vitro expanded, amniotic fluid stem cells. By means of a methodology unrequiring immune selection, we isolated and characterized different stem cell types from second-trimester human amniotic fluid samples (human amniotic fluid stem cells, HASCs). Of those populations, one was characterized by a fast doubling time, and cells were thus designated as fHASCs. Cells maintained their original phenotype under prolonged in vitro passaging, and they were able to originate embryoid bodies. Moreover, fHASCs exhibited regulatory properties when treated with interferon (IFN)-γ, including induction of the immunomodulatory enzyme indoleamine 2,3-dioxygenase 1 (IDO1). On coculture with human peripheral blood mononuclear cells, IFN-γ-treated fHASCs caused significantly decreased T-cell proliferation and increased frequency in CD4(+)  CD25(+)  FOXP3(+) regulatory T cells. Both effects required an intact IDO1 function and were cell contact-independent. An unprecedented finding in our study was that purified vesicles from IFN-γ-treated fHASCs abundantly expressed the functional IDO1 protein, and those vesicles were endowed with an fHASC-like regulatory function. In vivo, fHASCs were capable of immunoregulatory function, promoting allograft survival in a mouse model of allogeneic skin transplantation. This was concurrent with the expansion of CD4(+)  CD25(+)  Foxp3(+) T cells in graft-draining lymph nodes from recipient mice. Thus fHASCs, or vesicles thereof, may represent a novel opportunity for immunoregulatory maneuvers both in vitro and in vivo.

A nitric oxide-dependent cross-talk between class I and III histone deacetylases accelerates skin repair

In a mouse model of skin repair we found that the class I-IIa histone deacetylase inhibitor trichostatin A accelerated tissue regeneration. Unexpectedly, this effect was suppressed by Sirtinol, a class III histone deacetylase (HDAC) (sirtuin)-selective inhibitor. The role of sirtuins (SIRTs) was then investigated by using resveratrol and a novel SIRT1-2-3 activator, the MC2562 compound we synthesized recently. Both resveratrol and MC2562 were effective in accelerating wound repair. The local administration of natural or synthetic SIRT activators, in fact, significantly accelerated skin regeneration by increasing keratinocyte proliferation. In vitro experiments revealed that the activation of SIRTs stimulated keratinocyte proliferation via endothelial NO synthase phosphorylation and NO production. In this condition, the class I member HDAC2 was found S-nitrosylated on cysteine, a post-transduction modification associated with loss of activity and DNA binding capacity. After deacetylase inhibitor or SIRT activator treatment, ChIP showed, in fact, a significant HDAC2 detachment from the promoter region of insulin growth factor I (IGF-I), fibroblast growth factor 10 (FGF-10), and Epithelial Growth Factor (EGF), which may be the final recipients and effectors of the SIRT-NO-HDAC signaling cascade. Consistently, the effect of SIRT activators was reduced in the presence of NG-nitro-L-arginine methyl ester (L-NAME), a general inhibitor of NO synthesis. In conclusion, the NO-dependent cross-talk among class III and I histone deacetylases suggests an unprecedented signaling pathway important for skin repair.

P300/CBP associated factor regulates nitroglycerin-dependent arterial relaxation by N(ε)-lysine acetylation of contractile proteins

OBJECTIVE

To address the role of epigenetic enzymes in the process of arterial vasorelaxation and nitrate tolerance, in vitro and in vivo experiments were performed in the presence or absence of glyceryl trinitrate (GTN) or histone deacetylases/histone acetylases modulators.

METHODS AND RESULTS

In vitro single GTN administration rapidly increased cGMP synthesis and protein N(ε)-lysine acetylation in rat smooth muscle cells, including myosin light chain and smooth muscle actin. This phenomenon determined a decrease in myosin light chain phosphorylation and actomyosin formation. These effects were abolished by prolonged exposure to GTN and rescued by treatment with trichostatin A. In vivo, adult male rats were treated for 72 hours with subcutaneous injections of GTN alone or in combination with the histone deacetylases inhibitors trichostatin A, suberoylanilide hydroxamic acid, MS-27-275, or valproic acid. Ex vivo experiments performed on aortic rings showed that the effect of tolerance was reversed by all proacetylation drugs, including the p300/CREB binding protein-associated factor activator pentadecylidenemalonate 1b (SPV106). Any response to GTN was abolished by anacardic acid, a potent histone acetylases inhibitor.

CONCLUSIONS

This study establishes the following points: (1) GTN treatment increases histone acetylases activity; (2) GTN-activated p300/CREB binding protein-associated factor increases protein N(ε)-lysine acetylation; (3) N(ε)-lysine acetylation of contractile proteins influences GTN-dependent vascular response. Hence, combination of epigenetic drugs and nitroglycerin may be envisaged as a novel treatment strategy for coronary artery disease symptoms and other cardiovascular accidents of ischemic origin.

NO points to epigenetics in vascular development

Our understanding of epigenetic mechanisms important for embryonic vascular development and cardiovascular differentiation is still in its infancy. Although molecular analyses, including massive genome sequencing and/or in vitro/in vivo targeting of specific gene sets, has led to the identification of multiple factors involved in stemness maintenance or in the early processes of embryonic layers specification, very little is known about the epigenetic commitment to cardiovascular lineages. The object of this review will be to outline the state of the art in this field and trace the perspective therapeutic consequences of studies aimed at elucidating fundamental epigenetic networks. Special attention will be paid to the emerging role of nitric oxide in this field.

Smad-interacting protein-1 and microRNA 200 family define a nitric oxide-dependent molecular circuitry involved in embryonic stem cell mesendoderm differentiation

OBJECTIVE

Smad-interacting protein-1 (Sip1/ZEB2) is a transcriptional repressor of the telomerase reverse transcriptase catalytic subunit (Tert) and has recently been identified as a key regulator of embryonic cell fate with a phenotypic effect similar, in our opinion, to that reported for nitric oxide (NO). Remarkably, SIP1/ZEB2 is a known target of the microRNA 200 (miR-200) family. In this light, we postulated that Sip1/ZEB2 and the miR-200 family could play a role during the NO-dependent differentiation of mES.

METHODS AND RESULTS

The results of the present study show that Sip1/ZEB2 expression is downregulated during the NO-dependent expression of mesendoderm and early cardiovascular precursor markers, including Flk1 and CXCR4 in mES. Coincidently, members of the miR-200 family, namely miR-429, -200a, -200b, and -200c, were transcriptionally induced in parallel to mouse Tert. This regulation occurred at the level of chromatin. Remarkably, miR-429/miR-200a overexpression or Sip1/ZEB2 knockdown by short hairpin RNA interference elicited a gene expression pattern similar to that of NO regardless of the presence of leukemia inhibitory factor.

CONCLUSIONS

These results are the first demonstrating that the miR-200 family and Sip1/ZEB2 transcription factor are regulated by NO, indicating an unprecedented molecular circuitry important for telomerase regulation and early differentiation of mES.

Nitric oxide determines mesodermic differentiation of mouse embryonic stem cells by activating class IIa histone deacetylases: potential therapeutic implications in a mouse model of hindlimb ischemia

In human endothelial cells, nitric oxide (NO) results in class IIa histone deacetylases (HDACs) activation and marked histone deacetylation. It is unknown whether similar epigenetic events occur in embryonic stem cells (ESC) exposed to NO and how this treatment could influence ESC therapeutic potential during tissue regeneration.This study reports that the NO-dependent class IIa HDACs subcellular localization and activity decreases the global acetylation level of H3 histones in ESC and that this phenomenon is associated with the inhibition of Oct4, Nanog, and KLF4 expression. Further, a NO-induced formation of macromolecular complexes including HDAC3, 4, 7, and protein phosphatase 2A (PP2A) have been detected. These processes correlated with the expression of the mesodermal-specific protein brachyury (Bry) and the appearance of several vascular and skeletal muscle differentiation markers. These events were abolished by the class IIa-specific inhibitor MC1568 and by HDAC4 or HDAC7 short interfering RNA (siRNA). The ability of NO to induce mesodermic/cardiovascular gene expression prompted us to evaluate the regenerative potential of these cells in a mouse model of hindlimb ischemia. We found that NO-treated ESCs injected into the cardiac left ventricle selectively localized in the ischemic hindlimb and contributed to the regeneration of muscular and vascular structures. These findings establish a key role for NO and class IIa HDACs modulation in ESC mesodermal commitment and enhanced regenerative potential in vivo.

Histone deacetylase inhibitors: keeping momentum for neuromuscular and cardiovascular diseases treatment

Histone deacetylases (HDACs) are enzymes with a pleiotropic range of intracellular localizations and actions. They are principally involved in the withdrawal of acetyl-groups from a large number of nuclear and cytoplasmic proteins including nuclear core histones as well as cytoskeletal proteins and metabolically relevant enzymes. Initial findings indicated that HDAC inhibitors (DIs) could be successfully applied in a variety of cancer treatment protocols as a consequence of their anti-proliferative and pro-apoptotic properties. Recent observations, however, enlightened the important therapeutic effects of DIs in experimental animal models for arthritis, neurodegenerative and neuromuscular disorders, heart ischemia, cardiac hypertrophy, heart failure and arrhythmias. A small number of clinical trials are now open or planned for the near future to verify the therapeutic properties of DIs in non-cancer-related diseases. This review summarizes some of the most important observations and concepts aroused by the most recent experimental application of DIs to neuromuscular and cardiac diseases.

Nitric oxide deficiency determines global chromatin changes in Duchenne muscular dystrophy

The present study provides evidence that abnormal patterns of global histone modification are present in the skeletal muscle nuclei of mdx mice and Duchenne muscular dystrophy (DMD) patients. A combination of specific histone H3 modifications, including Ser-10 phosphorylation, acetylation of Lys 9 and 14, and Lys 79 methylation, were found enriched in muscle biopsies from human patients affected by DMD and in late-term fetuses, early postnatal pups, or adult mdx mice. In this context, chromatin immunoprecipitation experiments showed an enrichment of these modifications at the loci of genes involved in proliferation or inflammation, suggesting a regulatory effect on gene expression. Remarkably, the reexpression of dystrophin induced by gentamicin treatment or the administration of nitric oxide (NO) donors reversed the abnormal pattern of H3 histone modifications. These findings suggest an unanticipated link between the dystrophin-activated NO signaling and the remodeling of chromatin. In this context, the regulation of class IIa histone deacetylases (HDACs) 4 and 5 was found altered as a consequence of the reduced NO-dependent protein phosphatase 2A activity, indicating that both NO and class IIa HDACs are important for satellite cell differentiation and gene expression in mdx mice. In conclusion, this work provides the first evidence of a role for NO as an epigenetic regulator in DMD.

Nitric Oxide Modulates Chromatin Folding in Human Endothelial Cells via Protein Phosphatase 2A Activation and Class II Histone Deacetylases Nuclear Shuttling

Nitric oxide (NO) modulates important endothelial cell (EC) functions and gene expression by a molecular mechanism which is still poorly characterized. Here we show that in human umbilical vein ECs (HUVECs) NO inhibited serum-induced histone acetylation and enhanced histone deacetylase (HDAC) activity. By immunofluorescence and Western blot analyses it was found that NO induced class II HDAC4 and 5 nuclear shuttling and that class II HDACs selective inhibitor MC1568 rescued serum-dependent histone acetylation above control level in NO-treated HUVECs. In contrast, class I HDACs inhibitor MS27–275 had no effect, indicating a specific role for class II HDACs in NO-dependent histone deacetylation. In addition, it was found that NO ability to induce HDAC4 and HDAC5 nuclear shuttling involved the activation of the protein phosphatase 2A (PP2A). In fact, HDAC4 nuclear translocation was impaired in ECs expressing small-t antigen and exposed to NO. Finally, in cells engineered to express a HDAC4-Flag fusion protein, NO induced the formation of a macromolecular complex including HDAC4, HDAC3, HDAC5, and an active PP2A. The present results show that NO-dependent PP2A activation plays a key role in class II HDACs nuclear translocation.

Non coding RNA and brain

Small non coding RNAs are a group of very different RNA molecules, present in virtually all cells, with a wide spectrum of regulatory functions which include RNA modification and regulation of protein synthesis. They have been isolated and characterized in all organisms and tissues, from Archaeobacteria to mammals. In mammalian brain there are a number of these small molecules, which are involved in neuronal differentiation as well as, possibly, in learning and memory. In this manuscript, we analyze the present knowledge about the function of the most important groups of small non-coding RNA present in brain: small nucleolar RNAs, small cytoplasmic RNAs, and microRNAs. The last ones, in particular, appear to be critical for dictating neuronal cell identity during development and to play an important role in neurite growth, synaptic development and neuronal plasticity.

Molecular recognition in helix-loop-helix and helix-loop-helix-leucine zipper domains. Design of repertoires and selection of high affinity ligands for natural proteins

Helix-loop-helix (HLH) and helix-loop-helix-leucine zipper (HLHZip) are dimerization domains that mediate selective pairing among members of a large transcription factor family involved in cell fate determination. To investigate the molecular rules underlying recognition specificity and to isolate molecules interfering with cell proliferation and differentiation control, we assembled two molecular repertoires obtained by directed randomization of the binding surface in these two domains. For this strategy we selected the Heb HLH and Max Zip regions as molecular scaffolds for the randomization process and displayed the two resulting molecular repertoires on lambda phage capsids. By affinity selection, many domains were isolated that bound to the proteins Mad, Rox, MyoD, and Id2 with different levels of affinity. Although several residues along an extended surface within each domain appeared to contribute to dimerization, some key residues critically involved in molecular recognition could be identified. Furthermore, a number of charged residues appeared to act as switch points facilitating partner exchange. By successfully selecting ligands for four of four HLH or HLHZip proteins, we have shown that the repertoires assembled are rather general and possibly contain elements that bind with sufficient affinity to any natural HLH or HLHZip molecule. Thus they represent a valuable source of ligands that could be used as reagents for molecular dissection of functional regulatory pathways.

Differential expression and localization of calmodulin-dependent phosphodiesterase genes during ontogenesis of chick dorsal root ganglion

The level and characteristics of 3'-5'-cyclic nucleotide phosphodiesterase (PDE) activity in chick dorsal root ganglion (DRG) extracts of 5-day posthatching chicken (P5) and E10 and E18 embryos were studied. At all stages, PDE activity is stimulated by calcium and calmodulin. A 5-fold increase in basal cAMP and cGMP PDE activity is evident from E10 to E18, while from E18 to P5 basal PDE activity remains constant. Ion exchange chromatography elution profile indicates that PDE1 isoforms represent the bulk of the PDE activity present. Inhibition studies were performed in order to distinguish the activity due to PDE1A, B and C. Western blot analysis using anti-mammalian PDE1A, B and C specific antibodies was also performed. Densitometric analysis of the stained bands reveals that PDE1B and PDE1C display a prominent increase between day 10 and day 18 of development (eight- and 3.6 fold, respectively) while a more limited increase (1.6- and 1.5-fold) is observed between E18 and P5; on the other hand PDE1A shows continuously increasing levels throughout development. Immunohistochemical analysis was performed with isoform specific antibodies used for western blot analysis. PDE1A immunoreactivity is found in the cytoplasm and fibers of several neurons differing in size and distributed throughout the ganglion. PDE1B staining is evident on all neurons, however, fibers appear very faintly labelled. All neurons appear stained by PDE1C antibody, although the intensity of immunostaining is always heterogeneous in different neuronal populations: no staining was evident on fibers or in non-neural cells. The distinct spatial and temporal expression patterns of PDE1 isoforms may indicate their different physiological roles in developing and mature chick DRG.

Making decisions through Myc

c-Myc is a transcriptional regulator involved in carcinogenesis through its role in growth control and cell cycle progression. Here we attempt to relate its role in stimulating the G1-S transition to the ability to affect functioning of key cell cycle regulators, and we focus on how its property of modulating transcription of a wide range of target genes could explain its capacity to affect multiple pathways leading to proliferation, apoptosis, growth, and transformation.