UBQLN4 Represses Homologous Recombination and Is Overexpressed in Aggressive Tumors.

Genomic instability can be a hallmark of both human genetic disease and cancer. We identify a deleterious UBQLN4 mutation in families with an autosomal recessive syndrome reminiscent of genome instability disorders. UBQLN4 deficiency leads to increased sensitivity to genotoxic stress and delayed DNA double-strand break (DSB) repair. The proteasomal shuttle factor UBQLN4 is phosphorylated by ATM and interacts with ubiquitylated MRE11 to mediate early steps of homologous recombination-mediated DSB repair (HRR). Loss of UBQLN4 leads to chromatin retention of MRE11, promoting non-physiological HRR activity in vitro and in vivo. Conversely, UBQLN4 overexpression represses HRR and favors non-homologous end joining. Moreover, we find UBQLN4 overexpressed in aggressive tumors. In line with an HRR defect in these tumors, UBQLN4 overexpression is associated with PARP1 inhibitor sensitivity. UBQLN4 therefore curtails HRR activity through removal of MRE11 from damaged chromatin and thus offers a therapeutic window for PARP1 inhibitor treatment in UBQLN4-overexpressing tumors.

PHF2 regulates homology-directed DNA repair by controlling the resection of DNA double strand breaks.

Post-translational histone modifications and chromatin remodelling play a critical role controlling the integrity of the genome. Here, we identify histone lysine demethylase PHF2 as a novel regulator of the DNA damage response by regulating DNA damage-induced focus formation of 53BP1 and BRCA1, critical factors in the pathway choice for DNA double strand break repair. PHF2 knockdown leads to impaired BRCA1 focus formation and delays the resolution of 53BP1 foci. Moreover, irradiation-induced RPA phosphorylation and focus formation, as well as localization of CtIP, required for DNA end resection, to sites of DNA lesions are affected by depletion of PHF2. These results are indicative of a defective resection of double strand breaks and thereby an impaired homologous recombination upon PHF2 depletion. In accordance with these data, Rad51 focus formation and homology-directed double strand break repair is inhibited in cells depleted for PHF2. Importantly, we demonstrate that PHF2 knockdown decreases CtIP and BRCA1 protein and mRNA levels, an effect that is dependent on the demethylase activity of PHF2. Furthermore, PHF2-depleted cells display genome instability and are mildly sensitive to the inhibition of PARP. Together these results demonstrate that PHF2 promotes DNA repair by homologous recombination by controlling CtIP-dependent resection of double strand breaks.

Musical dynamics in early triadic interactions: a case study.

Research of the last 30 years showed the importance of music for psychological development. Communicative musicality studies described musical organisations in dyadic interactions (adult-baby). However, other perspectives proposed that, from the beginning of life, there are early triadic interactions (adult-object-baby) that should also be analysed. Following previous research, we hypothesised that early triadic interactions have a structured musical organisation. We recorded a 2-month-old child interacting with his mother and an object in their home and performed a microgenetic quantitative-qualitative analysis. Given the child's age, we focused on musical characteristics of the mother's actions. To our knowledge, this is the first study to combine data processing provided by ELAN, Finale, and Matlab-MIRtoolbox. Our analysis shows that the child participates in triadic interactions in which the mother communicates about and through the maraca using musical resources in increasingly complex ways. Musical structuring happens at the intersegment, intrasequence, and intersequence levels, and involves different musical parameters. We suggest musical organisation in early triadic interactions follows a holographic structure in which each piece carries information about dynamic processes of different timescales. Results highlight the importance of considering objects and their uses to better understand early communicative musicality.

Getting away from the point: the emergence of ostensive gestures and their functions.

Within developmental psychology, pointing gestures have received a great deal of attention, while ostensive gestures have been overlooked in terms of their emergence and intentionality. In a longitudinal and micro-genetic study with six children at 9, 11, and 13 months of age, we codified gesture production of children within second-by-second data frames. We identified 480 instances of gestures and categorised whether they were of ostensive, ostensive-indexical, or indexical nature. We specified the communicative function of each gesture by analysing the object involved and their circumstances of production. Data analysis include frequencies, binomial tests, proportion comparisons, and repeated measures ANOVA. We identified a phatic function in other-directed gestures, as well as exploratory and private functions in self-directed gestures. This has important implications for child development since ostensive gestures are easier to produce and to understand than pointing. The consideration of objects would be essential for defining the communicative function of gestures.

A Pragmatic Turn in the Study of Early Executive Functions by Object Use and Gestures. A Case Study from 8 to 17 Months of Age at a Nursery School.

The two first years of life are critical in the development of Executive Functions (EF). However, very little is known about their early manifestations, how they develop, how they relate to other psychological constructions or the status of other people's influence in this early development. The study of EFs has been carried out through standardised tasks, but some authors question their ecological validity and suggest an approach involving everyday situations and the challenges that children set for themselves. In this article we first review these issues in relation to the first manifestations of EFs. We secondly present a longitudinal case study at nursery school of a child between the ages of 8 and 17 months, considering the challenges and the means he employed in order to resolve them. We found that, from 8 months of age, the child gave himself challenges in relation to the functional uses of objects and instruments. He regulated his own behavior both through object and instrument uses and private gestures. He also involved the teacher at 17 months. This finding suggests that (1) the material world is particularly important in these early manifestations of EF, (2) teachers' interventions are essential. Implications of the findings for early years education are discussed.

Evaluation of plasma cortisol during fasting test in patients with endogenous hyperinsulinemic hypoglycemia. Fifteen years experience.

BACKGROUND: Endogenous hyperinsulinemic hypoglycemia (EHH) is a rare clinical condition. The aim of this study was to evaluate baseline plasma cortisol concentration and its concentration during hypoglycemic crisis in fasting tests (FT) performed in our center. Secondarily, the aim was to establish the relationship between baseline cortisol and the time of evolution of EHH. MATERIAL AND METHODS: A retrospective, observational, descriptive study was carried out which included patients with hypoglycemic disorder with positive FT. RESULTS: Of a total of 21 patients, 16 presented insulinoma, 1 nesidioblastosis, 2 malignant insulinoma and 2 EHH without pathological diagnosis. The time from the onset of symptoms to diagnosis was 2 years (Q1=1.5-Q2=5.5). The comparison between median baseline cortisol (BC)=11.8 mcg/dl (nmol/L 340.68) (Q1=9-Q3=14.1) and median cortisol during hypoglycemic episode (HC)=11.6 mcg/dl (nmol/L: 303.44) (Q1=7.8-Q3=16.1) showed no differences (Z=-0.08; P>.05). When correlating BC with HC, no significant relationship was observed (r=0.16; P>.05). When correlating the glycemic value in the crisis and the HC, a slight negative trend was found (r=-0.53; P=.01). In addition, we found that recurrent hypoglycemic disorder is associated with lower baseline cortisol values ​​the longer the time of its evolution. CONCLUSION: We confirmed that cortisol values ​​remain low during hypoglycemic episodes, reinforcing the hypothesis of lack of response of this counterregulatory hormone in cases of recurrent hypoglycemia.

The development of categorisation and conceptual thinking in early childhood: methods and limitations.

We present a systematic and qualitative review of academic literature on early conceptual development (0-24 months of age), with an emphasis on methodological aspects. The final sample of our review included 281 studies reported in 115 articles. The main aims of the article were four: first, to organise studies into sets according to methodological similarities and differences; second, to elaborate on the methodological procedures that characterise each set; third, to circumscribe the empirical indicators that different sets of studies consider as proof of the existence of concepts in early childhood; last, to identify methodological limitations and to propose possible ways to overcome them. We grouped the studies into five sets: preference and habituation experiments, category extension tasks, object sorting tasks, sequential touching tasks and object examination tasks. In the "Results" section, we review the core features of each set of studies. In the "Discussion" and "Conclusions" sections, we describe, for one thing, the most relevant methodological shortcomings. We end by arguing that a situated, semiotic and pragmatic perspective that emphasises the importance of ecological validity could open up new avenues of research to better understand the development of concepts in early childhood.

Methylation of the central transcriptional regulator KLF4 by PRMT5 is required for DNA end resection and recombination.

Cell fitness and survival upon exposure to DNA damage depends on the repair of DNA lesions. Interestingly, cellular identity does affect and finetunes such response, although the molecular basis of such differences between tissues and cell types is not well understood. Thus, a possibility is that DNA repair itself is controlled by the mechanisms that govern cell identity. Here we show that the KLF4, involved in cellular homeostasis, proliferation, cell reprogramming and cancer development, directly regulates resection and homologous recombination proficiency. Indeed, resection efficiency follows KLF4 protein levels, i.e. decreases upon KLF4 downregulation and increases when is overexpressed. Moreover, KLF4 role in resection requires its methylation by the methyl-transferase PRMT5. Thus, PRMT5 depletion not only mimics KLF4 downregulation, but also showed an epistatic genetic relationship. Our data support a model in which the methylation of KLF4 by PRMT5 is a priming event required to license DNA resection and homologous recombination.

Early Understanding of Cardinal Number Value: Semiotic, Social, and Pragmatic Dimensions in a Case Study with a Child from 2 to 3 Years Old.

Studies on cardinality date back many years, and it remains a current research issue today. Indeed, despite the many findings on the topic, there is still controversy surrounding when and how children understand cardinality. The main studies on this understanding employs the "how many" question in situations involving the quantification of objects, analyzing the relationship between counting and cardinality. In the present study, we argue that it is essential to consider how cardinality is used in the context in which it arises, including the in- depth consideration of semiotic, social, and pragmatic dimensions, in order to fully comprehend the topic. We analyze in microgenesis the interaction between a two-year-old girl and her mother when they are playing a game requiring the understanding and use of cardinality through five sessions conducted over the course of a year. Our findings suggest that, in the proposed situation, cardinal understanding develops slowly and gradually requires an integrated body of resources (such as gestures and the use of objects). In highlighting the role of semiotics and social interactions in the development of cardinal understanding, this research underscores the fundamental role that early education should play in its development.

Communicative Mediation by Adults in the Construction of Symbolic Uses by Infants.

Adult semiotic mediation in the origin and evolution of the first symbolic uses of objects by infants in contexts of triadic interactions was investigated. Six infant-parent dyads interacting together with ten objects were observed longitudinally from 9 to 15 months of age, with an interval of three months between each observation. The communicative mediators used by adults, in the form of demonstrations and ostensive gestures, decrease as infants grow up. The orchestration of these semiotic mediators also decreases and the functions of the demonstrations change. At the beginning, the adults use them merely to demonstrate the symbolic uses of object, but later they use them to evaluate, complete or correct the symbolic uses by the infants. The semiotic mediators are first used to guide the child at the level of attention and later at the level of cultural practices of symbolic uses of objects. These changes in communicative mediators and their functions reveal the educational role of adults through adjustment in communication, always in tune with the infant's knowledge and performance.

Artificial Pancreas: Clinical Study in Latin America Without Premeal Insulin Boluses.

BACKGROUND: Emerging therapies such as closed-loop (CL) glucose control, also known as artificial pancreas (AP) systems, have shown significant improvement in type 1 diabetes mellitus (T1DM) management. However, demanding patient intervention is still required, particularly at meal times. To reduce treatment burden, the automatic regulation of glucose (ARG) algorithm mitigates postprandial glucose excursions without feedforward insulin boluses. This work assesses feasibility of this new strategy in a clinical trial. METHODS: A 36-hour pilot study was performed on five T1DM subjects to validate the ARG algorithm. Subjects wore a subcutaneous continuous glucose monitor (CGM) and an insulin pump. Insulin delivery was solely commanded by the ARG algorithm, without premeal insulin boluses. This was the first clinical trial in Latin America to validate an AP controller. RESULTS: For the total 36-hour period, results were as follows: average time of CGM readings in range 70-250 mg/dl: 88.6%, in range 70-180 mg/dl: 74.7%, <70 mg/dl: 5.8%, and <50 mg/dl: 0.8%. Results improved analyzing the final 15-hour period of this trial. In that case, the time spent in range was 70-250 mg/dl: 94.7%, in range 70-180 mg/dl: 82.6%, <70 mg/dl: 4.1%, and <50 mg/dl: 0.2%. During the last night the time spent in range was 70-250 mg/dl: 95%, in range 70-180 mg/dl: 87.7%, <70 mg/dl: 5.0%, and <50 mg/dl: 0.0%. No severe hypoglycemia occurred. No serious adverse events were reported. CONCLUSIONS: The ARG algorithm was successfully validated in a pilot clinical trial, encouraging further tests with a larger number of patients and in outpatient settings.

Importance of hydrophobic interactions in the single-chained cationic surfactant-DNA complexation.

The goal of this work was to understand the key factors determining the DNA compacting capacity of single-chained cationic surfactants. Fluorescence, zeta potential, circular dichroism, gel electrophoresis and AFM measurements were carried out in order to study the condensation of the nucleic acid resulting from the formation of the surfactant-DNA complexes. The apparent equilibrium binding constant of the surfactants to the nucleic acid, Kapp, estimated from the experimental results obtained in the ethidium bromide competitive binding experiments, can be considered directly related to the ability of a given surfactant as a DNA compacting agent. The plot of ln(Kapp) vs. ln(cmc), cmc being the critical micelle concentration, for all the bromide and chloride surfactants studied, was found to be a reasonably good linear correlation. This result shows that hydrophobic interactions mainly control the surfactant DNA compaction efficiency.

Rhythmic ostensive gestures: How adults facilitate infants' entrance into early triadic interactions.

For decades, the literature on the emergence of triadic interactions considers the end of the first year of life as the time when children become able to communicate with others intentionally about a referent. Prior to that, children only relate in dyads, either with someone else or with an object. However, several researchers claim that referents are not naturally given in human communication and that they need to be established in interaction with others. In this study, we focus on earlier triadic interactions initiated by adults, when young babies still require an adult to bring the material world within their reach. In these early triadic interactions, ostensive gestures (with the object in the hand) are one of the first means of enabling the establishment of shared reference. Such gestures are easier to understand since sign (gesture) and referent (object) coincide. We conducted a longitudinal study with 6 babies filmed at 2, 3 and 4 months old in interaction with their mothers and a sounding object (a maraca). We analyzed different communicative initiatives by the adult and the child's responses. The results show that children come to understand the adult's communicative intention gradually through interaction. Adults include children in organized communicative "niches" based on ostensive actions, both through ostensive gestures and demonstrations of the use of the object. Consequently, the first shared understandings between adult and child take place around the object and its uses. Rhythm is a powerful tool used to structure the interaction. Eventually, adults provide space to children to actively interact with the sounding object themselves. These results highlight the importance of considering ostensive actions as a communicative tool that favors joint attention and action. They also bring some light to the interdependence between a child who actively perceives and acts, and the structured situation that the adult organizes for them.

CtIP-Specific Roles during Cell Reprogramming Have Long-Term Consequences in the Survival and Fitness of Induced Pluripotent Stem Cells.

Acquired genomic instability is one of the major concerns for the clinical use of induced pluripotent stem cells (iPSCs). All reprogramming methods are accompanied by the induction of DNA damage, of which double-strand breaks are the most cytotoxic and mutagenic. Consequently, DNA repair genes seem to be relevant for accurate reprogramming to minimize the impact of such DNA damage. Here, we reveal that reprogramming is associated with high levels of DNA end resection, a critical step in homologous recombination. Moreover, the resection factor CtIP is essential for cell reprogramming and establishment of iPSCs, probably to repair reprogramming-induced DNA damage. Our data reveal a new role for DNA end resection in maintaining genomic stability during cell reprogramming, allowing DNA repair fidelity to be retained in both human and mouse iPSCs. Moreover, we demonstrate that reprogramming in a resection-defective environment has long-term consequences on stem cell self-renewal and differentiation.

DNA end resection requires constitutive sumoylation of CtIP by CBX4.

DNA breaks are complex DNA lesions that can be repaired by two alternative mechanisms: non-homologous end-joining and homologous recombination. The decision between them depends on the activation of the DNA resection machinery, which blocks non-homologous end-joining and stimulates recombination. On the other hand, post-translational modifications play a critical role in DNA repair. We have found that the SUMO E3 ligase CBX4 controls resection through the key factor CtIP. Indeed, CBX4 depletion impairs CtIP constitutive sumoylation and DNA end processing. Importantly, mutating lysine 896 in CtIP recapitulates the CBX4-depletion phenotype, blocks homologous recombination and increases genomic instability. Artificial fusion of CtIP and SUMO suppresses the effects of both the non-sumoylatable CtIP mutant and CBX4 depletion. Mechanistically, CtIP sumoylation is essential for its recruitment to damaged DNA. In summary, sumoylation of CtIP at lysine 896 defines a subpopulation of the protein that is involved in DNA resection and recombination.The choice between non-homologous end-joining and homologous recombination to repair a DNA double-strand break depends on activation of the end resection machinery. Here the authors show that SUMO E3 ligase CBX4 sumoylates subpopulation of CtIP to regulate recruitment to breaks and resection.

Targeting the centriolar replication factor STIL synergizes with DNA damaging agents for treatment of ovarian cancer.

Advanced ovarian cancer is an incurable disease. Thus, novel therapies are required. We wished to identify new therapeutic targets for ovarian cancer. ShRNA screen performed in 42 ovarian cancer cell lines identified the centriolar replication factor STIL as an essential gene for ovarian cancer cells. This was verified in-vivo in orthotopic human ovarian cancer mouse models. STIL depletion by administration of siRNA in neutral liposomes resulted in robust anti-tumor effect that was further enhanced in combination with cisplatin. Consistent with this finding, STIL depletion enhanced the extent of DNA double strand breaks caused by DNA damaging agents. This was associated with centrosomal depletion, ongoing genomic instability and enhanced formation of micronuclei. Interestingly, the ongoing DNA damage was not associated with reduced DNA repair. Indeed, we observed that depletion of STIL enhanced canonical homologous recombination repair and increased BRCA1 and RAD51 foci in response to DNA double strand breaks. Thus, inhibition of STIL significantly enhances the efficacy of DNA damaging chemotherapeutic drugs in treatment of ovarian cancer.

The connection between language and the world: a paradox of the linguistic turn?

Alex Gillespie and Flora Cornish draw on the dialogic turn as they consider that, in order to interpret the meaning of an utterance, it is necessary to emphasize its contextual nature. Among other aspects, they address what context is and what is being done while speaking. Taking these two issues as point of departure, it is worth pondering on (1) what revolves around language and what the status of nonlinguistic semiotic systems is for the philosophers of language, (2) Umberto Eco's critique of the Philosophy of Language, which has not problematized the pre-linguistic relationship with things, and (3) how ontogenesis may shed light on this scheme where linguistic and nonlinguistic aspects are inevitably interrelated. I will reflect on the pragmatic aspects in adult-child communication at its pre-linguistic level. I will underscore the key role played by the object as a complex referent and as a tool for communication.

The development of categorisation and conceptual thinking in early childhood: methods and limitations

Abstract We present a systematic and qualitative review of academic literature on early conceptual development (0-24 months of age), with an emphasis on methodological aspects. The final sample of our review included 281 studies reported in 115 articles. The main aims of the article were four: first, to organise studies into sets according to methodological similarities and differences; second, to elaborate on the methodological procedures that characterise each set; third, to circumscribe the empirical indicators that different sets of studies consider as proof of the existence of concepts in early childhood; last, to identify methodological limitations and to propose possible ways to overcome them. We grouped the studies into five sets: preference and habituation experiments , category extension tasks , object sorting tasks , sequential touching tasks and object examination tasks . In the "Results" section, we review the core features of each set of studies. In the "Discussion" and "Conclusions" sections, we describe, for one thing, the most relevant methodological shortcomings. We end by arguing that a situated, semiotic and pragmatic perspective that emphasises the importance of ecological validity could open up new avenues of research to better understand the development of concepts in early childhood.

The Rhythmic, Sonorous and Melodic Components of Adult-Child-Object Interactions Between 2 and 6 Months Old.

Adults mediate the relationship between material reality and children, according to functional units of cultural relevance. This paper explores early development of semiotic systems in infants, analyzing rhythmic, sonorous and melodic components, which enable adult-child interaction with and about objects. The triads (with sonorous and non-sonorous objects) was studied longitudinally at age 2, 4 and 6 months. We propose that rhythmic, sonorous and melodic components conformed one of the basic semiotic systems upon the adult's action relies (through gestures and uses of objects) in order to segment and organize objects in the world. Likewise, children actively respond to these presentations and seek sounds for themselves when they are able to interact with the object more autonomously.