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The complex proteoglycan (PG) composition in bone is addressed together with the specific role played by PGs in bone biology, as regulatory molecules for bone resorption and their involvement in bone tumor development. The roles of anl PG (HSPG) families as bone pro-resorptive agents and promoters of asteolytic tumor have made them good targets for new therapeutic approaches to these osteolytic bone tumors.

Aims: Cohen syndrome (CS) is an uncommon autosomal recessive disorder due to mutations in vacuolar protein sorting 13B, with an intermittent presence of neutropenia. Contrary to other clinical phenotypic features, oral health has been little investigated in CS. We described oral health and dental hygiene in a cohort of CS patients. Methods and Results: Twelve CS patients with neutropenia (<1500/mm3) were recruited in the dental department of Dijon University Hospital (France). Patients underwent oral examination, and blood samples were collected. Oral health markers were described and compared between patients with moderate and severe neutropenia (<500/mm3). In 12 patients (mean age = 21.1 years, SD = 13.7, six females), 45.5% brushed at least twice daily their teeth, and the same percentage annually visited a dentist. Dental plaque index was high (mean = 1.7, SD = 1.4). So was the number of lost teeth per patient, notably among adults (mean = 13.8, SD = 9.8). Elevated markers of periodontitis were noted as percentage of bleeding dental sites (mean = 70.2%, SD = 45.2%) or Gingival Index (mean = 2.2, SD = 1.0). The severity of neutropenia was correlated to the level of tooth‐loss (P =.03). Conclusion: This study highlighted in CS patients worrisome oral health and dental follow‐up in the context of intellectual disability with behavioural anomalies. More attention is needed by care‐givers on oral condition in CS. [ABSTRACT FROM AUTHOR]

Introduction Pigmentary mosaicism (PM) manifests by pigmentation anomalies along Blaschko's lines and represents a clue toward the molecular diagnosis of syndromic intellectual disability (ID). Together with new insights on the role for lysosomal signalling in embryonic stem cell differentiation, mutations in the X-linked transcription factor 3 (TFE3) have recently been reported in five patients. Functional analysis suggested these mutations to result in ectopic nuclear gain of functions. Materials and methods Subsequent data sharing allowed the clustering of de novo TFE3 variants identified by exome sequencing on DNA extracted from leucocytes in patients referred for syndromic ID with or without PM. Results We describe the detailed clinical and molecular data of 17 individuals harbouring a de novo TFE3 variant, including the patients that initially allowed reporting TFE3 as a new disease-causing gene. The 12 females and 5 males presented with pigmentation anomalies on Blaschko's lines, severe ID, epilepsy, storage disorder-like features, growth retardation and recognisable facial dysmorphism. The variant was at a mosaic state in at least two male patients. All variants were missense except one splice variant. Eleven of the 13 variants were localised in exon 4, 2 in exon 3, and 3 were recurrent variants. Conclusion This series further delineates the specific storage disorder-like phenotype with PM ascribed to de novo TFE3 mutation in exons 3 and 4. It confirms the identification of a novel X-linked human condition associated with mosaicism and dysregulation within the mechanistic target of rapamycin (mTOR) pathway, as well as a link between lysosomal signalling and human development. [ABSTRACT FROM AUTHOR]

Heterozygous microdeletions of chromosome 15q13.3 (MIM: 612001) show incomplete penetrance and are associated with a highly variable phenotype that may include intellectual disability, epilepsy, facial dysmorphism and digit anomalies. Rare patients carrying homozygous deletions show more severe phenotypes including epileptic encephalopathy, hypotonia and poor growth. For years, CHRNA7 (MIM: 118511), was considered the candidate gene that could account for this syndrome. However, recent studies in mouse models have shown that OTUD7A/CEZANNE2 (MIM: 612024), which encodes for an ovarian tumor (OTU) deubiquitinase, should be considered the critical gene responsible for brain dysfunction. In this study, a patient presenting with severe global developmental delay, language impairment and epileptic encephalopathy was referred to our genetics center. Trio exome sequencing (tES) analysis identified a homozygous OTUD7A missense variant (NM_130901.2:c.697C>T), predicted to alter an ultraconserved amino acid, p.(Leu233Phe), lying within the OTU catalytic domain. Its subsequent segregation analysis revealed that the parents, presenting with learning disability, and brother were heterozygous carriers. Biochemical assays demonstrated that proteasome complex formation and function were significantly reduced in patient‐derived fibroblasts and in OTUD7A knockout HAP1 cell line. We provide evidence that biallelic pathogenic OTUD7A variation is linked to early‐onset epileptic encephalopathy and proteasome dysfunction. [ABSTRACT FROM AUTHOR]

SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor gene involved in the tumorigenesis of a spectrum of solid cancers. Heterozygous SASH1 variants are known to cause autosomal-dominant dyschromatosis. Homozygosity mapping and whole-exome sequencing were performed in a consanguineous Moroccan family with two affected siblings presenting an unclassified phenotype associating an abnormal pigmentation pattern (hypo- and hyperpigmented macules of the trunk and face and areas of reticular hypo- and hyperpigmentation of the extremities), alopecia, palmoplantar keratoderma, ungueal dystrophy and recurrent spinocellular carcinoma. We identified a homozygous variant in SASH1 (c.1849G>A; p.Glu617Lys) in both affected individuals. Wound-healing assay showed that the patient's fibroblasts were better able than control fibroblasts to migrate. Following the identification of SASH1 heterozygous variants in dyschromatosis, we used reverse phenotyping to show that autosomal-recessive variants of this gene could be responsible for an overlapping but more complex phenotype that affected skin appendages. SASH1 should be added to the list of genes responsible for autosomal-dominant and -recessive genodermatosis, with no phenotype in heterozygous patients in the recessive form, and to the list of genes responsible for a predisposition to skin cancer. [ABSTRACT FROM AUTHOR]

ABSTRACT Over one hundred VPS13B mutations are reported in Cohen syndrome (CS). Most cases exhibit a homogeneous phenotype that includes intellectual deficiency (ID), microcephaly, facial dysmorphism, slender extremities, truncal obesity, progressive chorioretinal dystrophy, and neutropenia. We report on a patient carrying two VPS13B splicing mutations with an atypical phenotype that included microcephaly, retinopathy, and congenital neutropenia, but neither obesity nor ID. RNA analysis of the IVS34+2T_+3AinsT mutation did not reveal any abnormal splice fragments but mRNA quantification showed a significant decrease in VPS13B expression. RNA sequencing analysis up- and downstream from the IVS57+2T>C mutation showed abnormal splice isoforms. In contrast to patients with typical CS, who express only abnormal VPS13B mRNA and truncated protein, a dose effect of residual normal VPS13B protein possibly explains the incomplete phenotype in the patient. This observation emphasizes that VPS13B analysis should be performed in cases of congenital neutropenia associated with retinopathy, even in the absence of ID, therefore extending the VPS13B phenotype spectrum. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Cohen syndrome (CS) is a rare autosomal recessive condition caused by mutations and/or large rearrangements in the VPS13B gene. CS clinical features, including developmental delay, the typical facial gestalt, chorioretinal dystrophy (CRD) and neutropenia, are well described. CS diagnosis is generally raised after school age, when visual disturbances lead to CRD diagnosis and to VPS13B gene testing. This relatively late diagnosis precludes accurate genetic counselling. The aim of this study was to analyse the evolution of CS facial features in the early period of life, particularly before school age (6 years), to find clues for an earlier diagnosis. Photographs of 17 patients with molecularly confirmed CS were analysed, from birth to preschool age. By comparing their facial phenotype when growing, we show that there are no special facial characteristics before 1 year. However, between 2 and 6 years, CS children already share common facial features such as a short neck, a square face with micrognathia and full cheeks, a hypotonic facial appearance, epicanthic folds, long ears with an everted upper part of the auricle and/or a prominent lobe, a relatively short philtrum, a small and open mouth with downturned corners, a thick lower lip and abnormal eye shapes. These early transient facial features evolve to typical CS facial features with aging. These observations emphasize the importance of ophthalmological tests and neutrophil count in children in preschool age presenting with developmental delay, hypotonia and the facial features we described here, for an earlier CS diagnosis. [ABSTRACT FROM AUTHOR]

Interleukin-34 (IL-34) is a newly discovered regulator of myeloid lineage differentiation, proliferation, and survival, acting via the macrophage-colony stimulating factor receptor (M-CSF receptor, c-fms). M-CSF, the main ligand for c-fms, is required for osteoclastogenesis and has been already identified as a critical contributor of the pathogenesis of giant cell tumours of bone (GCTs), tumours rich in osteoclasts. According to the key role of M-CSF in osteoclastogenesis and GCTs, the expression of IL-34 in human GCTs was first assessed. Quantitative analysis of IL-34 mRNA expression in 14 human GCTs revealed expression of this cytokine in GCTs as well as M-CSF and c-fms. Immunohistochemistry demonstrated that osteoclast-like cells exhibited a huge immunostaining for IL-34 and that mononuclear stromal cells were slightly positive for this protein. In contrast to osteoblasts, bone-resorbing osteoclasts showed very strong staining for IL-34, suggesting its potential role in the pathogenesis of GCTs by facilitating osteoclast formation. The role of IL-34 in osteoclastogenesis was then studied in murine and human models. IL-34 was able to support RANKL-induced osteoclastogenesis in the absence of M-CSF in all models. Multinucleated cells generated in the presence of IL-34 and RANKL expressed specific osteoclastic markers and resorbed dentine. IL-34 induced phosphorylation of ERK 1/2 and Akt through the activation of c-fms, as revealed by the inhibition of signalling by a specific c-fms tyrosine kinase inhibitor. Furthermore, IL-34 stimulated RANKL-induced osteoclastogenesis by promoting the adhesion and proliferation of osteoclast progenitors, and had no effect on osteoclast survival. Overall, these data reveal that IL-34 can be entirely substituted for M-CSF in RANKL-induced osteoclastogenesis, thus identifying a new biological activity for this cytokine and a contribution to the pathogenesis of GCTs. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bone remodeling involves synthesis of organic matrix by osteoblasts and bone resorption by osteoclasts. A tight collaboration between these two cell types is essential to maintain a physiological bone homeostasis. Thus, osteoblasts control bone-resorbing activities and are also involved in osteoclast differentiation. Any disturbance between these effectors leads to the development of skeletal abnormalities and/or bone diseases. In this context, the determination of key genes involved in bone cell differentiation is a new challenge to treat any skeletal disorders. Different models are used to study the differentiation process of these cells, but all of them use pre-engaged progenitor cells, allowing us to study only the latest stages of the differentiation. Embryonic stem (ES) cells come from the inner mass of the blastocyst prior its implantation to the uterine wall. Because of their capacity to differentiate into all germ layers, and so into all tissues of the body, ES cells represent the best model by which to study earliest stages of bone cell differentiation. Osteoblasts are generated by two methods, one including the generation of embryoid body, the other not. Mineralizing cells are obtained after 2 weeks of culture and express all the specific osteoblastic markers (alkaline phosphatase, type I collagen, osteocalcin, and others). Osteoclasts are generated from a single-cell suspension of ES cells seeded on a feeder monolayer, and bone-resorbing cells expressing osteoclastic markers such as tartrate-resistant alkaline phosphatase or receptor activator of nuclear factor κB are obtained within 11 days. The aim of this review is to present recent discoveries and advances in the differentiation of both osteoblasts and osteoclasts from ES cells. [ABSTRACT FROM AUTHOR]

The physiologic function of the progressive hyperleptinemia of diet-induced obesity is unknown. However, that lipotoxicity in nonadipose tissues of congenitally unleptinized obese rodents is far greater than in hyperleptinemic diet-induced obesity rodents has suggested an antilipotoxic role. To test this hypothesis, mice with severe lipotoxic cardiomyopathy, induced transgenically by cardiomyocyte-specific overexpression of the acyl CoA synthase (ACS) gene, were made hyperleptinemic by treatment with recombinant adenovirus containing the leptin cDNA. Normoleptinemic control ACS-transgenic mice developed severe dilated cardiomyopathy with thickened left ventricular walls and profound impairment of systolic function on echocardiogram; histologically, there was severe myofiber disorganization and interstitial fibrosis, with intracytoplasmic lipid vacuoles identifiable by electron microscope. By contrast, the hearts of hyperleptinemic ACS-transgenic mice appeared normal, with normal echocardiograms and cardiac triglyceride (TG) contents. Their lower myocardial TG content was ascribed primarily to profound lowering of plasma TG and free fatty acids; free fatty acids were 17% of normal at 8 weeks. Additionally, enhanced myocardial AMP-activated protein kinase phosphorylation may have increased fatty acid oxidation, thereby contributing to the lowering of lipid stores. We conclude that obesity-level hyperleptinemia protects the heart from lipotoxicity. [ABSTRACT FROM AUTHOR]

To determine if increased local production of glucocorticoids by the pancreatic islets might play a role in the spontaneous noninsulin-dependent diabetes mellitus of obesity, we compared islet 11β-HSD-1 mRNA and activity in islets of obese prediabetic and diabetic Zucker Diabetic Fatty (ZDF) (fa/fa) rats and lean wild-type (+/+) controls. In diabetic rat islets, both mRNA and enzymatic activity of the enzyme were increased in proportion to the hyperglycemia. Troglitazone (TGZ) treatment, beginning at 6 weeks of age, prevented the hyperglycemia, the hyperlipidemia, and the increase in 11β-HSD-1. To determine if the metabolic abnormalities had caused the 11β-HSD-1 increase, prediabetic islets were cultured in high or low glucose or in 2:1 oleate:palmitate for 3 days. Neither nutrient enhanced the expression of 11β-HSD-1. We conclude that 11β-HSD-1 expression and activity are increased in islets of diabetic, but not prediabetic ZDF rats, and that TGZ prevents both the increase in 11β-HSD-1 and the diabetes. [Copyright &y& Elsevier]

Sustained hyperleptinemia induced in normal rats causes the rapid disappearance of body fat. This is attributed to a marked increase in uncoupled fatty acid oxidation in the white adipocytes, which also occurs in hyperthyroidism. Because hyperleptinemic rats have normal plasma T3 or T4 levels, we tested the possibility of “localized hyperthyroidism” due to increased conversion of T4 to T3 in the adipose tissue. We therefore induced sustained hyperleptinemia in normal rats by intravenous injection of recombinant adenovirus containing the leptin cDNA (AdCMV-leptin) and measured the mRNA and the activity of enzymes involved in T4 metabolism in the disappearing fat. The epididymal fat pad remnants exhibited a decrease in mRNA of deiodinase 1 and a doubling of deiodinase 2 mRNA (p<0.05), but their enzyme activities did not differ from normoleptinemic controls. To determine if thyroid hormone was required for the fat-wasting action of hyperleptinemia, we infused AdCMV-leptin into rats made athyroid by total thyroidectomy or by methimazole therapy. The fat loss in hyperleptinemic athyroid rats was as great as in euthyroid controls. We conclude that the fat-wasting effect of sustained hyperleptinemia does not involve “local hyperthyroidism” in white adipose tissue and does not require thyroid hormone. [Copyright &y& Elsevier]

HSP110 is induced by different stresses and, through its anti-apoptotic and chaperoning properties, helps the cells to survive these adverse situations. In colon cancers, HSP110 is abnormally abundant. We have recently showed that colorectal cancer (CRC) patients with microsatellite instability (MSI) had an improved response to chemotherapy because they harbor an HSP110 inactivating mutation (HSP110DE9). In this work, we have used patients' biopsies and human CRC cells grownin vitroandin vivo(xenografts) to demonstrate that (1) HSP110 is secreted by CRC cells and that the amount of this extracellular HSP110 is strongly decreased by the expression of the mutant HSP110DE9, (2) Supernatants from CRC cells overexpressing HSP110 or purified recombinant human HSP110 (LPS-free) affect macrophage differentiation/polarization by favoring a pro-tumor, anti-inflammatory profile, (3) Conversely, inhibition of HSP110 (expression of siRNA, HSP110DE9 or immunodepletion) induced the formation of macrophages with a cytotoxic, pro-inflammatory profile. (4) Finally, this effect of extracellular HSP110 on macrophages seems to implicate TLR4. These results together with the fact that colorectal tumor biopsies with HSP110 high were infiltrated with macrophages with a pro-tumoral profile while those with HSP110 low were infiltrated with macrophages with a cytotoxic profile, suggest that the effect of extracellular HSP110 function on macrophages may also contribute to the poor outcomes associated with HSP110 expression. [ABSTRACT FROM AUTHOR]

Short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay (SHORT) syndrome is a developmental disorder with an unknown genetic cause and hallmarks that include insulin resistance and lack of subcutaneous fat. We ascertained two unrelated individuals with SHORT syndrome, hypothesized that the observed phenotype was most likely due to de novo mutations in the same gene, and performed whole-exome sequencing in the two probands and their unaffected parents. We then confirmed our initial observations in four other subjects with SHORT syndrome from three families, as well as 14 unrelated subjects presenting with syndromic insulin resistance and/or generalized lipoatrophy associated with dysmorphic features and growth retardation. Overall, we identified in nine affected individuals from eight families de novo or inherited PIK3R1 mutations, including a mutational hotspot (c.1945C>T [p.Arg649Trp]) present in four families. PIK3R1 encodes the p85α, p55α, and p50α regulatory subunits of class IA phosphatidylinositol 3 kinases (PI3Ks), which are known to play a key role in insulin signaling. Functional data from fibroblasts derived from individuals with PIK3R1 mutations showed severe insulin resistance for both proximal and distal PI3K-dependent signaling. Our findings extend the genetic causes of severe insulin-resistance syndromes and provide important information with respect to the function of PIK3R1 in normal development and its role in human diseases, including growth delay, Rieger anomaly and other ocular affections, insulin resistance, diabetes, paucity of fat, and ovarian cysts. [Copyright &y& Elsevier]

Demonstrates the role of the immunoglobulin G-like domain in leukemia inhibitory factor (LIF) binding. Potential to modulate receptor affinity in the family with very limited amino acid changes; Production and expression of shgp190myc and its single point mutant; Enhancement of the blocking activity of shgp90 on hLIF-dependent cell proliferation.

PIK3CA -related overgrowth spectrum is caused by mosaicism mutations in the PIK3CA gene. These mutations, which are also observed in various types of cancer, lead to a constitutive activation of the PI3K/AKT/mTOR pathway, increasing cell proliferation. Heat shock transcription factor 1 (HSF1) is the major stress-responsive transcription factor. Recent findings indicate that AKT phosphorylates and activates HSF1 independently of heat-shock in breast cancer cells. Here, we aimed to investigate the role of HSF1 in PIK3CA -related overgrowth spectrum. We observed a higher rate of proliferation and increased phosphorylation of AKT and p70S6K in mutant fibroblasts than in control cells. We also found elevated phosphorylation and activation of HSF1, which is directly correlated to AKT activation. Specific AKT inhibitors inhibit HSF1 phosphorylation as well as HSF1-dependent gene transcription. Finally, we demonstrated that targeting HSF1 with specific inhibitors reduced the proliferation of mutant cells. As there is currently no curative treatment for PIK3CA -related overgrowth spectrum, our results identify HSF1 as a new potential therapeutic target. • PIK3CA -related overgrowth spectrum is characterized by increased cell proliferation. • Strong activation of HSF1 is found in PIK3CA -related overgrowth spectrum fibroblasts. • AKT inhibitors reduces HSF1 activation and HSF1-dependent gene transcription. • HSF1 inhibition blocks the PIK3CA -related overgrowth spectrum proliferation. [ABSTRACT FROM AUTHOR]

Shprintzen-Goldberg syndrome (SGS) is characterized by severe marfanoid habitus, intellectual disability, camptodactyly, typical facial dysmorphism, and craniosynostosis. Using family-based exome sequencing, we identified a dominantly inherited heterozygous in-frame deletion in exon 1 of SKI. Direct sequencing of SKI further identified one overlapping heterozygous in-frame deletion and ten heterozygous missense mutations affecting recurrent residues in 18 of the 19 individuals screened for SGS; these individuals included one family affected by somatic mosaicism. All mutations were located in a restricted area of exon 1, within the R-SMAD binding domain of SKI. No mutation was found in a cohort of 11 individuals with other marfanoid-craniosynostosis phenotypes. The interaction between SKI and Smad2/3 and Smad 4 regulates TGF-β signaling, and the pattern of anomalies in Ski-deficient mice corresponds to the clinical manifestations of SGS. These findings define SGS as a member of the family of diseases associated with the TGF-β-signaling pathway. [Copyright &y& Elsevier]