Computational Tool to Design Small Synthetic Inhibitors Selective for XIAP-BIR3 Domain

X-linked inhibitor of apoptosis protein (XIAP) exercises its biological function by locking up and inhibiting essential caspase-3, -7 and -9 toward apoptosis execution. It is overexpressed in multiple human cancers, and it plays an important role in cancer cells' death skipping. Inhibition of XIAP-BIR3 domain and caspase-9 interaction was raised as a promising strategy to restore apoptosis in malignancy treatment. However, XIAP-BIR3 antagonists also inhibit cIAP1-2 BIR3 domains, leading to serious side effects. In this study, we worked on a theoretical model that allowed us to design and optimize selective synthetic XIAP-BIR3 antagonists. Firstly, we assessed various MM-PBSA strategies to predict the XIAP-BIR3 binding affinities of synthetic ligands. Molecular dynamics simulations using hydrogen mass repartition as an additional parametrization with and without entropic term computed by the interaction entropy approach produced the best correlations. These simulations were then exploited to generate 3D pharmacophores. Following an optimization with a training dataset, five features were enough to model XIAP-BIR3 synthetic ligands binding to two hydrogen bond donors, one hydrogen bond acceptor and two hydrophobic groups. The correlation between pharmacophoric features and computed MM-PBSA free energy revealed nine residues as crucial for synthetic ligand binding: Thr308, Glu314, Trp323, Leu307, Asp309, Trp310, Gly306, Gln319 and Lys297. Ultimately, and three of them seemed interesting to use to improve XIAP-BR3 versus cIAP-BIR3 selectivity: Lys297, Thr308 and Asp309.

PROTAC technology: A new drug design for chemical biology with many challenges in drug discovery

Target Protein Degradation TPD is a new avenue and revolutionary for therapeutics because redefining the principles of classical drug discovery and guided by event-based target activity rather than the occupancy-driven activity. Since the discovery of the first PROTAC in 2001, TPD represents a rapidly growing technology, with applications in both drug discovery and chemical biology. Over the last decade, many questions have been raised and today the knowledge gained by each team has elucidated a number of them, although there is still a long way to go. The objective of this work is to present the challenges that the PROTAC strategy has very recently addressed in drug design and discovery by presenting extremely recent results from the literature and to provide guidelines in the drug design of new PROTACs as successful therapeutic modality for medicinal chemists.

Role of metalloproteases in the CD95 signaling pathways

CD95L (also known as FasL or CD178) is a member of the tumor necrosis family (TNF) superfamily. Although this transmembrane ligand has been mainly considered as a potent apoptotic inducer in CD95 (Fas)-expressing cells, more recent studies pointed out its role in the implementation of non-apoptotic signals. Accordingly, this ligand has been associated with the aggravation of inflammation in different auto-immune disorders and in the metastatic occurrence in different cancers. Although it remains to decipher all key factors involved in the ambivalent role of this ligand, accumulating clues suggest that while the membrane bound CD95L triggers apoptosis, its soluble counterpart generated by metalloprotease-driven cleavage is responsible for its non-apoptotic functions. Nonetheless, the metalloproteases (MMPs and ADAMs) involved in the CD95L shedding, the cleavage sites and the different stoichiometries and functions of the soluble CD95L remain to be elucidated. To better understand how soluble CD95L triggers signaling pathways from apoptosis to inflammation or cell migration, we propose herein to summarize the different metalloproteases that have been described to be able to shed CD95L, their cleavage sites and the biological functions associated with the released ligands. Based on these new findings, the development of CD95/CD95L-targeting therapeutics is also discussed.

A convenient synthetic route towards H-bisphosphinates

A practical generalisable procedure to synthesize hydroxymethylene H-bisphosphinates has been optimised. Unlike previous reports, numerous alkyl (including an alendronate bisphosphinate analogue) or (hetero)aryl compounds were rapidly obtained in satisfactory to excellent yields. A side product could have been identified as a phosphino-phosphonate isomer and plausible mechanistic pathways are proposed here. Moreover to check the literature data, a pKa value study was also performed.

Maternal attachment style and depression associated with childbirth: preliminary results from a European and US cross-cultural study

Background

Insecure attachment style relates to major depression in women, but its relationship to depression associated with childbirth is largely unknown. A new UK-designed measure, the Attachment Style Interview (ASI), has potential for cross-cultural use as a risk marker for maternal disorder.

Aims

To establish the reliability of the ASI across centres, its stability over a 9-month period, and its associations with social context and majoror minor depression.

Method

The ASI was used by nine centres antenatally on 204 women, with 174 followed up 6 months postnatally. Interrater reliability was tested and the ASI was repeated on a subset of 96 women. Affective disorder was assessed by means of the Structured Clinical Interview for DSM–IV.

Results

Satisfactory interrater reliability was achieved with relatively high stability rates at follow-up. Insecure attachment related to lower social class position and more negative social context. Specific associations of avoidant attachment style (angry–dismissive or withdrawn) with antenatal disorder, and anxious style (enmeshed or fearful) with postnatal disorder were found.

Conclusions

The ASI can be used reliably in European and US centres as a measure for risk associated with childbirth. Its use will contribute to theoretically underpinned preventive action for disorders associated with childbirth.

[Infants' attachment security in a vulnerable French sample]

INTRODUCTION

Attachment is a long lasting emotional link established between infants and their caregivers. The quality of early relationships allows infants to safely explore their environment and contribute to the establishment of a broad range of social skills. Several intervention programs targeting infant attachment have been implemented in different contexts, showing diverse degrees of efficacy.

OBJECTIVE

The present paper describes, for the first time, children's attachment quality distributions in a French multi-risk population, with a preventive intervention, usual or reinforced.

METHOD

In the CAPEDP study (Parenting and Attachment in Early Childhood: reducing mental health disorder risks and promoting resilience), a sub-sample of 117 women was recruited to assess the effects of this home-visiting program on children's attachment security. With that intent, the Strange Situation Paradigm was used when infants were between 12 and 16 months of age.

RESULTS

In the intervention group, 63% (n=41) of the infants were coded as secure, while 15% (n=10) of them were coded as insecure-avoidant and 22% (n=14) as insecure-ambivalent/resistant. 56% (n=29) of control group infants (usual care) were coded as secure, while 27% (n=14) were coded as insecure-avoidant and 17% (n=9) as insecure-ambivalent/resistant. Even if the percentage of children with a secure attachment in the reinforced intervention group was higher than that of the control group, this difference did not reach the threshold of significance [Chi² (2)=2.40, P=0.30].

DISCUSSION

Intervention group distributions were closer to normative samples, and these distributions show the clinical impact of our program. In general, preventive interventions focused on attachment quality have moderate effects but, in our case, several factors might have contributed to lower the statistical impact of the program. Firstly, the control group cannot be considered has having received zero intervention for two reasons: (a) the French usual perinatal health system (Maternal and Infant Protection System) is particularly generous and (b) the effect of this usual system might have been increased by the project intensive assessment protocol (6 visits during 28 months). Secondly, it is possible that the full effect of the intervention had not yet been detected because, when a child's attachment was assessed, only two thirds of the intervention visits had been performed (29 of 44 visits). A "sleeper effect" is still possible: we hope that a more clear result will be seen when children are assessed again, at 48 months, in our follow-up study (CAPEDP-A II). By clarifying the mechanisms involved in the development of a secure attachment, our study aims to contribute and refine the development of early preventive intervention strategies in high perinatal and psychosocial vulnerability contexts.

Prévenir la dépression postnatale. Les résultats de la recherche CAPEDP

La recherche CAPEDP est une étude randomisée d’intervention préventive précoce des troubles de santé de la mère et de l’enfant basée sur des visites à domicile débutant durant le troisième trimestre de grossesse et se poursuivant jusqu’aux deux ans de l’enfant. Nous présenterons les résultats concernant la dépression maternelle (DPN) dont on connaît l’importance aussi bien en raison de sa prévalence (10–15 %) en population générale, que de ses conséquences sur le développement de l’enfant. Quatre cent quarante femmes sont recrutées et randomisées en deux groupes : primipares, âgées de moins de 26 ans, et au moins un facteur de risque parmi : un faible niveau d’éducation, des revenus faibles et/ou être isolées. Le groupe intervention bénéficie de VAD menées par des psychologues. La symptomatologie de la DPN est évaluée à l’inclusion à 3 mois post-partum, les scores moyens à l’EPDS sont respectivement de 9,4 (5,4) pour le groupe témoin et de 8,6 (5,4) pour le groupe intervention (p = 0,18). Pour certains sous-groupes de femmes ayant bénéficié de l’intervention les scores EPDS sont plus faibles que le groupe témoin : celles avec peu de symptômes dépressifs en prénatal (EPDS < 8) ; celles qui pensent être avec le père pour élever leur enfant ; et celles avec un niveau d’éducation supérieur au Brevet des collèges. CAPEDP n’a pas démontré d’efficacité pour prévenir la DPN à 3 mois. Les analyses post hoc montrent que l’intervention peut être efficace pour des femmes moins vulnérables. Les premiers résultats concernant les effets de l’intervention à 6 et 12 mois ainsi qu’une analyse de trajectoires de dépression des mères.

[Attachment process between an infant and his/her mother: the first year]

Attachment theory is focused upon the development of the attachment process organized jointly by the child and the environmental factors which contribute to the development of the feeling of security. The authors focus on the mother-baby relationships and describe the normative process of attachment relationships during the first year of life. The ethologic perspective of this development is also summarized. The steps of the developing attachment relationship are described. The description of motherhood is focused on the bonding process, which is a more immediate and biologically based process and on caregiving which is a symmetrical motivational system as complex as the attachment one. The main factors known as having an impact on the two processes are described.

[About offsprings of mothers with anorexia nervosa: what about clinical practice in pediatric settings?]

The authors first present the methodological issues raised by studies of the offspring of mothers with anorexia nervosa. Malnutrition and low weight appear to be the main consequences for the baby. Feeding mother/child interactions are more likely to be disturbed during later childhood. Emotional or psychological consequences are not well yet studied.

Contextual Assessment of the Maternity Experience: development of an instrument for cross-cultural research

BACKGROUND

There is evidence that stressors may trigger the onset of a depressive episode in vulnerable women. A new UK interview measure, the Contextual Assessment of the Maternity Experience (CAME), was designed to assess major risk factors for emotional disturbances, especially depression, during pregnancy and post-partum.

AIMS

With in the context of a cross-cultural study, to establish the usefulness of the CAME, and to test expected associations of the measure with characteristics of the social context and with major or minor depression.

METHOD

The CAME was administered antenatally and postnatally in ten study sites, respectively to 296 and 249 women. Affective disorder throughout pregnancy and up to 6 months postnatally was assessed by means of the Structured Clinical Interview for DSM-IVAxis I Disorders.

RESULTS

Adversity, poor relationship with either a partner or a confidant, and negative feelings about the pregnancy all predicted onset of depression during the perinatal period.

CONCLUSIONS

The CAME was able to assess major domains relevant to the psychosocial context of the maternity experience in different cultures. Overall, the instrument showed acceptable psychometric properties in its first use in different cultural settings.

The Edinburgh Postnatal Depression Scale (EPDS) and the detection of major depressive disorders in early postpartum: some concerns about false negatives

This paper presents a phenomenological study of three false negative cases according to the Edinburgh Postnatal Depression Scale (EPDS) of major depressive disorder identified by a semi-structured clinical interview. In a study of 87 unselected women with 23 of them suffering from a major depressive disorder (according to the Research Diagnostic Criteria), three cases of major depressive disorders were not identified as potential cases by the EPDS. The symptomatology of these three false negative cases was also assessed by a semi-structured interview (Present State Examination). Comparisons between EPDS scores and the scores of two other self report questionnaires (the General Health Questionnaire-28 and the Center for Epidemiologic Studies-Depression Scale) suggest that EPDS is better at identifying depressed postnatal women with anhedonic and anxious symptomatology rather than those whose depression presents mainly with psychomotor retardation.

[Depressed mothers: the impact of depression on early interactions. An analysis of Anglo-Saxon studies]

Maternal depression remains a public health problem as indicated by many studies focusing on depression in mothers of young children. Although the high prevalence of depression in mothers of infants and young children is now a recognized fact, the detection and management of maternal depression in everyday practice still raises significant problems. This initial review centers on studies providing diagnostic guidelines. The problem of maternal depression and of its impact on the offspring is relevant to the issue of how qualities, abilities, and vulnerabilities are transmitted from one generation to the next. Psychoanalysts, infant psychiatrists, and developmental psychologists show great interest in this field. The current review was restricted to recent Anglo-Saxon studies on depression-related changes in early maternal behavior. The most striking findings are as follows: although depression affects maternal behavior overall, there is considerable variation across mothers; timing alterations (in terms of micro and macro sequences) in mother-child interactions occur in every case and are among the obstacles to harmony and synchronization; subtle alterations in the mother's response to her baby's signals preclude flexibility and anticipation.