Tumor budding as a risk factor for lymph node metastases in cutaneous squamous cell carcinoma: a systematic review and meta-analysis.

BACKGROUND: Current staging systems have limitations in stratifying high-risk cases of cutaneous squamous cell carcinoma (cSCC). Tumor budding (TB) has emerged as a potential prognostic factor in various cancers. OBJECTIVES: This systematic review and meta-analysis aimed to evaluate the prognostic significance of TB in predicting lymph node metastases (NM) in cSCC. METHODS: A comprehensive search of the PubMed, Web of Science, EMBASE, and Cochrane databases was conducted. Studies investigating the association of TB using a 5-bud cut-off and NM in cSCC were included. A meta-analysis was performed using odds ratios (OR) to evaluate the association between TB and NM. RESULTS: Six retrospective studies comprising 793 cSCC patients were included. The random-effects analysis showed a significant association between high TB (≥5 buds) and NM (OR = 13.29, 95% CI = 5.55; 31.86). DISCUSSION: Tumor budding is a promising histopathologic feature for predicting NM in cSCC. The results show a strong association between high TB and NM, supporting its utility as a risk factor for NM in cSCC. Its inclusion in clinical practice and cSCC staging might be helpful in the stratification of high-risk cases and guide optimal management strategies for each patient. However, further investigation is needed to determine standardized reporting guidelines for TB in cSCC.

Breslow density ability to predict melanoma survival: should it be used in clinical practice?

BACKGROUND: Breslow density (BD) is an estimation of melanoma volume, which has emerged as a novel histopathological prognostic biomarker. OBJECTIVES: Our aim was to evaluate the role of BD as predictor of patients´ survival and assess its prognostic value in relation to overall survival (OS), disease-free survival (DFS), melanoma-specific survival (MSS) and metastasis-free survival (MFS). METHODS: A retrospective observational study in a cohort of 107 patients with invasive melanoma was conducted. Kaplan-Meier and Log-rank tests were used for 10-year survival analysis. The ability of BD and Breslow thickness (BT) to predict survival was assessed using receiver operating characteristic curves. RESULTS: The average follow-up was 115 months excluding deaths. BD ≥65% showed lower survival rates compared with the BD<65% group (log-rank test p<0.001). Area under the curve (AUC) of BD ≥65% was higher than BT's for all studied survival rates except for melanoma-specific survival, in which absolute BD showed the highest value. CONCLUSIONS: BD is proposed as a simple, valuable and inexpensive histopathological feature that could provide with valuable information to current melanoma staging, since it has proved a statistically significant prognostic value in relation to survival in melanoma patients, and comparable 10-year survival prediction ability to BT.

Protein O-Fucosyltransferase 1 Undergoes Interdomain Flexibility in Solution.

Protein O-fucosyltransferase 1 (PoFUT1) is a GT-B fold enzyme that fucosylates proteins containing EGF-like repeats. GT-B glycosyltransferases have shown a remarkable grade of plasticity adopting closed and open conformations as a way of tuning their catalytic cycle, a feature that has not been observed for PoFUT1. Here, we analyzed Caenorhabditis elegans PoFUT1 (CePoFUT1) conformational behavior in solution by atomic force microscopy (AFM) and single-molecule fluorescence resonance energy transfer (SMF-FRET). Our results show that this enzyme is very flexible and adopts mainly compact conformations and to a lesser extend a highly dynamic population that oscillates between compact and highly extended conformations. Overall, our experiments illustrate the inherent complexity of CePoFUT1 dynamics, which might play a role during its catalytic cycle.

Molecular basis for the integration of environmental signals by FurB from Anabaena sp. PCC 7120.

FUR (Ferric uptake regulator) proteins are among the most important families of transcriptional regulators in prokaryotes, often behaving as global regulators. In the cyanobacterium Anabaena PCC 7120, FurB (Zur, Zinc uptake regulator) controls zinc and redox homeostasis through the repression of target genes in a zinc-dependent manner. In vitro, non-specific binding of FurB to DNA elicits protection against oxidative damage and avoids cleavage by deoxyribonuclease I. The present study provides, for the first time, evidence of the influence of redox environment in the interaction of FurB with regulatory zinc and its consequences in FurB-DNA-binding affinity. Calorimetry studies showed that, in addition to one structural Zn(II), FurB is able to bind two additional Zn(II) per monomer and demonstrated the implication of cysteine C93 in regulatory Zn(II) coordination. The interaction of FurB with the second regulatory zinc occurred only under reducing conditions. While non-specific FurB-DNA interaction is Zn(II)-independent, the optimal binding of FurB to target promoters required loading of two regulatory zinc ions. Those results combined with site-directed mutagenesis and gel-shift assays evidenced that the redox state of cysteine C93 conditions the binding of the second regulatory Zn(II) and, in turn, modulates the affinity for a specific DNA target. Furthermore, differential spectroscopy studies showed that cysteine C93 could also be involved in heme coordination by FurB, either as a direct ligand or being located near the binding site. The results indicate that besides controlling zinc homeostasis, FurB could work as a redox-sensing protein probably modifying its zinc and DNA-binding abilities depending upon environmental conditions.

A proactive role of water molecules in acceptor recognition by protein O-fucosyltransferase 2.

Protein O-fucosyltransferase 2 (POFUT2) is an essential enzyme that fucosylates serine and threonine residues of folded thrombospondin type 1 repeats (TSRs). To date, the mechanism by which this enzyme recognizes very dissimilar TSRs has been unclear. By engineering a fusion protein, we report the crystal structure of Caenorhabditis elegans POFUT2 (CePOFUT2) in complex with GDP and human TSR1 that suggests an inverting mechanism for fucose transfer assisted by a catalytic base and shows that nearly half of the TSR1 is embraced by CePOFUT2. A small number of direct interactions and a large network of water molecules maintain the complex. Site-directed mutagenesis demonstrates that POFUT2 fucosylates threonine preferentially over serine and relies on folded TSRs containing the minimal consensus sequence C-X-X-S/T-C. Crystallographic and mutagenesis data, together with atomic-level simulations, uncover a binding mechanism by which POFUT2 promiscuously recognizes the structural fingerprint of poorly homologous TSRs through a dynamic network of water-mediated interactions.

Prenatal Stress and Neurodevelopmental Plasticity: Relevance to Psychopathology.

Prenatal development constitutes a critical time for shaping adult behaviour and may set the stage for vulnerability to disease later in life. A wealth of information from humans as well as from animal research has revealed that exposure to hostile conditions during gestation may result in a series of coordinated biological responses aimed at enhancing the probability of survival, but could also increase the susceptibility to mental illness. Prenatal stress has been linked to abnormal cognitive, behavioural and psychosocial outcomes both in animals and in humans, but the underlying molecular and physiological mechanisms remain largely unknown. In this chapter, we shall review experimental data from studies reported for rats, since more information is available for them than for other species. The major focus of the present chapter is to update and discuss data on behavioural, functional and morphological effects of prenatal stress in rats that may have counterparts in prospective and/or retrospective studies of gestational stress in humans. This work contributes to understanding the role of neuronal plasticity in the long-term effects of developmental adversity on brain function and its implications for vulnerability to disease.

Quaternary organization in a bifunctional prokaryotic FAD synthetase: Involvement of an arginine at its adenylyltransferase module on the riboflavin kinase activity.

Prokaryotic FAD synthetases (FADSs) are bifunctional enzymes composed of two modules, the C-terminal module with ATP:riboflavin kinase (RFK) activity, and the N-terminus with ATP:FMN adenylyltransferase (FMNAT) activity. The FADS from Corynebacterium ammoniagenes, CaFADS, forms transient oligomers during catalysis. These oligomers are stabilized by several interactions between the RFK and FMNAT sites from neighboring protomers, which otherwise are separated in the monomeric enzyme. Among these inter-protomer interactions, the salt bridge between E268 at the RFK site and R66 at the FMNAT-module is particularly relevant, as E268 is the catalytic base of the kinase reaction. Here we have introduced point mutations at R66 to analyze the impact of the salt-bridge on ligand binding and catalysis. Interestingly, these mutations have only mild effects on ligand binding and kinetic properties of the FMNAT-module (where R66 is located), but considerably impair the RFK activity turnover. Substitutions of R66 also modulate the ratio between monomeric and oligomeric species and modify the quaternary arrangement observed by single-molecule methods. Therefore, our data further support the cross-talk between the RFK- and FMNAT-modules of neighboring protomers in the CaFADS enzyme, and establish the participation of R66 in the modulation of the geometry of the RFK active site during catalysis.

Sequential binding of FurA from Anabaena sp. PCC 7120 to iron boxes: exploring regulation at the nanoscale.

Fur (ferric uptake regulator) proteins are involved in the control of a variety of processes in most prokaryotes. Although it is assumed that this regulator binds its DNA targets as a dimer, the way in which this interaction occurs remains unknown. We have focused on FurA from the cyanobacterium Anabaena sp. PCC 7120. To assess the molecular mechanism by which FurA specifically binds to "iron boxes" in PfurA, we examined the topology arrangement of FurA-DNA complexes by atomic force microscopy. Interestingly, FurA-PfurA complexes exhibit several populations, in which one is the predominant and depends clearly on the regulator/promoter ratio on the environment. Those results together with EMSA and other techniques suggest that FurA binds PfurA using a sequential mechanism: (i) a monomer specifically binds to an "iron box" and bends PfurA; (ii) two situations may occur, that a second FurA monomer covers the free "iron box" or that joins to the previously used forming a dimer which would maintain the DNA kinked; (iii) trimerization in which the DNA is unbent; and (iv) finally undergoes a tetramerization; the next coming molecules cover the DNA strands unspecifically. In summary, the bending appears when an "iron box" is bound to one or two molecules and decreases when both "iron boxes" are covered. These results suggest that DNA bending contributes at the first steps of FurA repression promoting the recruitment of new molecules resulting in a fine regulation in the Fur-dependent cluster associated genes.

Prenatal restraint stress decreases the expression of alpha-7 nicotinic receptor in the brain of adult rat offspring.

Prenatal stress (PS) strongly impacts fetal brain development and function in adulthood. In normal aging and Alzheimer's disease, there is hypothalamic-pituitary-adrenal axis dysfunction and loss of cholinergic neurons and neuronal nicotinic acetylcholine receptors (nAChRs). This study investigated whether prenatal restraint stress affects nAChR expression in the brain of adult offspring. For PS, pregnant dams were placed in a plastic restrainer for 45 min, three times daily during the last week of pregnancy; controls were undisturbed. Male offspring were analyzed at postnatal day (PND) 60 (n = 4 rats per group). Western blot (WB) and fluorescence microscopy showed that PS decreased α7-AChR subunit expression (∼50%) in the frontal cortex in the adult offspring. PS decreased significantly the number of α7-AChR-expressing cells in the medial prefrontal cortex (by ∼25%) and in the sensory-motor cortex (by ∼20%) without affecting the total cell number in those areas. No alterations were found in the hippocampus by quantitative polymerase chain reaction (qPCR), or WB analysis, but a detailed fluorescence microscopy analysis showed that PS affected α7-AChR mainly in the CA3 and dentate gyrus subfields: PS decreased α7-AChR subunit expression by ∼25 and ∼30%, respectively. Importantly, PS decreased the number of α7-AChR-expressing cells and the total cell number (by ∼15 and 20%, respectively) in the dentate gyrus. PS differently affected α4-AChR: PS impaired its mRNA expression in the frontal cortex (by ∼50%), without affecting protein levels. These results demonstrate that disturbances during gestation produce long-term alterations in the expression pattern of α7-AChR in rat brain.

Prenatal maternal restraint stress exposure alters the reproductive hormone profile and testis development of the rat male offspring.

Several studies have demonstrated that the presence of stressors during pregnancy induces adverse effects on the neuroendocrine system of the offspring later in life. In the present work, we investigated the effects of early programming on the male reproductive system, employing a prenatal stress (PS) paradigm. This study found that when pregnant dams were placed in a plastic restrainer three times a day during the last week of pregnancy, the offspring showed reduced anogenital distance and delayed testicular descent. Serum luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels were decreased at postnatal day (PND) 28 and testosterone was decreased at PND 75. Increased testosterone plus dihydrotestosterone (T + DHT) concentrations correlated with increased testicular 5α Reductase-1 (5αR-1) mRNA expression at PND 28. Moreover, PS accelerated spermatogenesis at PND 35 and 60, and increased mean seminiferous tubule diameter in pubertal offspring and reduced Leydig cell number was observed at PND 35 and 60. PS offspring had increased androgen receptor (AR) mRNA level at PND 28, and at PND 35 had increased the numbers of Sertoli cells immunopositive for AR. Overall, the results confirm that stress during gestation can induce long-term effects on the male offspring reproductive system. Of particular interest is the pre-pubertal imbalance of circulating hormones that probably trigger accelerated testicular development, followed by an increase in total androgens and a decrease in testosterone concentration during adulthood. Exposure to an unfavourable intrauterine environment might prepare for harsh external conditions by triggering early puberty, increasing reproductive potential.

Age-dependent effects of prenatal stress on the corticolimbic dopaminergic system development in the rat male offspring.

We have previously demonstrated that prenatal stress (PS) exerts an impairment of midbrain dopaminergic (DA) system metabolism especially after puberty, suggesting a particular sensitivity of DA development to variations in gonadal hormonal peaks. Furthermore we demonstrated that PS alters the long term androgens profile of the rat male offspring from prepubertal to adult stages. In this work we evaluated the sexual hormones activational effects on the DA system by analysing PS effects on the dopaminergic D2-like (D2R) and on the gonadal hormones receptor levels on cortical and hippocampal areas of prepubertal and adult male offspring. We further evaluated the dendritic arborization in the same areas by quantifying MAP2 immunoexpresion. Our results show that PS affected oestrogen receptor alpha (ERα) expression: mRNA er1s and ERα protein levels were decreased on prefrontal cortex and hippocampus of adult offspring. Moreover, PS reduced D2R protein levels in hippocampus of prepubertal rats. Morphological studies revealed that prepubertal PS rats presented decreased MAP2 immunoexpression in both areas suggesting that PS reduces the number of dendritic arborizations. Our findings suggest that PS exerts long-term effects on the DA system by altering the normal connectivity in the areas, and by modulating the expression of D2R and ERα in an age-related pattern. Since the developing forebrain DA system was shown to be influenced by androgen exposure, and PS was shown to disrupt perinatal testosterone surges, our results suggest that prenatal insults might be affecting the organizational role of androgens and differentially modulating their activational role on the DA development.

Recent advances in sensing the inter-biomolecular interactions at the nanoscale - A comprehensive review of AFM-based force spectroscopy.

Biomolecular interactions underpin most processes inside the cell. Hence, a precise and quantitative understanding of molecular association and dissociation events is crucial, not only from a fundamental perspective, but also for the rational design of biomolecular platforms for state-of-the-art biomedical and industrial applications. In this context, atomic force microscopy (AFM) appears as an invaluable experimental technique, allowing the measurement of the mechanical strength of biomolecular complexes to provide a quantitative characterization of their interaction properties from a single molecule perspective. In the present review, the most recent methodological advances in this field are presented with special focus on bioconjugation, immobilization and AFM tip functionalization, dynamic force spectroscopy measurements, molecular recognition imaging and theoretical modeling. We expect this work to significantly aid in grasping the principles of AFM-based force spectroscopy (AFM-FS) technique and provide the necessary tools to acquaint the type of data that can be achieved from this type of experiments. Furthermore, a critical assessment is done with other nanotechnology techniques to better visualize the future prospects of AFM-FS.

Exploring the genetic background of the botulism neurotoxin BoNT/B2 in Spain.

To determine whether the neurotoxin BoNT/B2 causing botulism in Spain is clonal, the genetic diversity and phylogenetic relationships of Clostridium botulinum from food-borne episodes and infant cases of the condition were explored. The botulinum toxin gene (bont) subtype, the variable region of the flagellin gene (flaVR), and a seven-gene multi-locus sequence type were examined by sequencing 37 BoNT-positive cultures obtained over the period 2010 to 2022. Out of 37 botulism events, 16 food-borne episodes and 16 infant cases were associated with bont/b2. Eight bont/b2 alleles were detected [nucleotide distance range 0.0259-0.415%, Hunter and Gaston discrimination index (HGDI) 0.71]. The most common bont/b2 allele corresponded to that of strain Prevot 25 NCASE and its single and double locus variations (87.5%). Four known flaVR types were identified (HGDI 0.79), along with one previously unknown (flaVR-15). Sixteen sequence types (STs) (HGDI 0.89) were recorded including seven new STs (ST164-ST170; 10 new alleles) and five new STs (ST171-ST175; with new allele combinations) were also noted. Correlations among some STs and flaVR types were seen. Overall, the present results show that the combined analysis of bont/b2-flaVR-ST at the nucleotide level could be used to track botulism events in Spain. The neurotoxin BoNT/B2 has largely been responsible for human botulism in Spain. The polymorphism analysis of bont/b2, flaVR typing, and sequence type determinations, revealed a wide variety of clones to be responsible for human botulism, ruling out a common source of acquisition. IMPORTANCE Botulism, a potentially fatal disease, is classically characterized by a symmetrical descending flaccid paralysis, which if left untreated can lead to respiratory failure and death. Botulinum neurotoxin (BoNT), produced by certain species of Clostridium, is the most potent biological toxin known, and the direct cause of botulism. This study characterizes the acquisition in Spain of two forms of botulism, i.e., food-borne and infant botulism, which are largely caused by the main neurotoxin BoNT/B2. Polymorphism analysis of the bont/b2 gene, typing of the flagellin variable region sequence (flaVR), and multilocus sequence typing, were used to explore the genetic background of Clostridium botulinum group I. To our knowledge, this is the first phylogenetic and typing study of botulism undertaken in Spain.

Did COVID-19 lockdown delay actually worsen melanoma prognosis?

BACKGROUND: The COVID-19 lockdown possibly meant a delay in the diagnosis and treatment of melanoma and therefore, worsening its prognosis. This unique situation of diagnosis deferral is an exceptional opportunity to investigate melanoma biology. OBJECTIVES: To evaluate the immediate and mid-term impact of diagnosis delay on melanoma. METHODS: A retrospective observational study of melanoma diagnosed between March 14th 2019 and March 13th 2021. We compared the characteristics of melanomas diagnosed during the first 6-month period after the lockdown instauration and a second period after recovery of normal activity with the same periods of the previous year, respectively. RESULTS: A total of 119 melanomas were diagnosed. There were no differences in age, sex, incidence, location, presence of ulceration or mitoses, and in situ/invasive melanoma rate (p>0.05). After the recovery of the normal activity, Breslow thickness increased in comparison with the previous year (2.4 vs 1.9mm, p<0.05) resulting in a significant upstaging according to the AJCC 8th ed. (p<0.05). STUDY LIMITATIONS: The main limitation is that this is a single-center study. CONCLUSIONS: The COVID-19 lockdown implied a diagnosis delay leading to a mid-term increase in Breslow thickness and an upstaging of invasive melanomas. However, the detection deferral did not result in a higher progression of in situ to invasive melanoma, in our sample.

Early-Life Stress Reprograms Stress-Coping Abilities in Male and Female Juvenile Rats.

Prenatal stress (PS) is a major risk factor for the development of emotional disorders in adulthood that may be mediated by an altered hypothalamic-pituitary-adrenal axis response to stress. Although the early onset of stress-related disorders is recognized as a major public health problem, to date, there are relatively few studies that have examined the incidence of early-life stressors in younger individuals. In this study, we assessed PS impact on the stress-coping response of juvenile offspring in behavioral tests and in the induced molecular changes in the hippocampus. Furthermore, we assessed if pregnancy stress could be driving changes in patterns of maternal behavior during early lactation. We found that PS modified stress-coping abilities of both sex offspring. In the hippocampus, PS increased the expression of bdnf-IV and crfr1 and induced sex difference changes on glucocorticoids and BDNF mRNA receptor levels. PS changed the hippocampal epigenetic landscape mainly in male offspring. Stress during pregnancy enhanced pup-directed behavior of stressed dams. Our study indicates that exposure to PS, in addition to enhanced maternal behavior, induces dynamic neurobehavioral variations at juvenile ages of the offspring that should be considered adaptive or maladaptive, depending on the characteristics of the confronting environment. Our present results highlight the importance to further explore risk factors that appear early in life that will be important to allow timely prevention strategies to later vulnerability to stress-related disorders.

Enhanced Molecular Spin-Photon Coupling at Superconducting Nanoconstrictions.

We combine top-down and bottom-up nanolithography to optimize the coupling of small molecular spin ensembles to 1.4 GHz on-chip superconducting resonators. Nanoscopic constrictions, fabricated with a focused ion beam at the central transmission line, locally concentrate the microwave magnetic field. Drops of free-radical molecules have been deposited from solution onto the circuits. For the smallest ones, the molecules were delivered at the relevant circuit areas by means of an atomic force microscope. The number of spins Neff effectively coupled to each device was accurately determined combining Scanning Electron and Atomic Force Microscopies. The collective spin-photon coupling constant has been determined for samples with Neff ranging between 2 × 106 and 1012 spins, and for temperatures down to 44 mK. The results show the well-known collective enhancement of the coupling proportional to the square root of Neff. The average coupling of individual spins is enhanced by more than 4 orders of magnitude (from 4 mHz up to above 180 Hz), when the transmission line width is reduced from 400 µm down to 42 nm, and reaches maximum values near 1 kHz for molecules located on the smallest nanoconstrictions.

Non-invasive biomarkers of fetal brain development reflecting prenatal stress: An integrative multi-scale multi-species perspective on data collection and analysis.

Prenatal stress (PS) impacts early postnatal behavioural and cognitive development. This process of 'fetal programming' is mediated by the effects of the prenatal experience on the developing hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). We derive a multi-scale multi-species approach to devising preclinical and clinical studies to identify early non-invasively available pre- and postnatal biomarkers of PS. The multiple scales include brain epigenome, metabolome, microbiome and the ANS activity gauged via an array of advanced non-invasively obtainable properties of fetal heart rate fluctuations. The proposed framework has the potential to reveal mechanistic links between maternal stress during pregnancy and changes across these physiological scales. Such biomarkers may hence be useful as early and non-invasive predictors of neurodevelopmental trajectories influenced by the PS as well as follow-up indicators of success of therapeutic interventions to correct such altered neurodevelopmental trajectories. PS studies must be conducted on multiple scales derived from concerted observations in multiple animal models and human cohorts performed in an interactive and iterative manner and deploying machine learning for data synthesis, identification and validation of the best non-invasive detection and follow-up biomarkers, a prerequisite for designing effective therapeutic interventions.

Barriers to clopidogrel adherence following placement of drug-eluting stents.

BACKGROUND: Nonadherence to clopidogrel after drug-eluting stent (DES) placement is associated with in-stent thrombosis and adverse cardiac events. OBJECTIVE: To identify the incidence of and barriers associated with nonadherence to clopidogrel in patients receiving DES. METHODS: Patients who received a DES between March 1, 2004, and August 31, 2005, from a single academic medical center were eligible. Telephone interviews were conducted 6 or more months following discharge. Nonadherence was defined as premature discontinuation of or less than 80% adherence to clopidogrel. Patients were asked to identify barriers to adherence. Differences between adherent and nonadherent patients were analyzed using chi(2) and t-test analysis. RESULTS: Of the 674 patients identified, 257 (38%) participated. The nonadherence rate was 20%. The majority (58%) of nonadherent patients discontinued therapy prematurely. Patients identified the main reason for discontinuation as medical barriers (18.56%), including perceived adverse effects (9.28%). The incidence of rash was higher in patients who were nonadherent (12% vs 4%; p = 0.049). Overall, 49% of patients recalled receiving discharge counseling regarding adverse effects. A financial barrier was identified by 22 (42%) patients in the nonadherent and 73 (36%) in the adherent group, of whom 64% and 52%, respectively, reported having insurance coverage for medications. Adherent patients reported higher copays ($29.69 vs $18.14; p = 0.01). CONCLUSIONS: Prospective studies should be conducted to aid in identifying patients at risk for nonadherence and possible in-stent thrombosis in order to identify interventions to improve adherence.

Prenatal stress increases adult vulnerability to cocaine reward without affecting pubertal anxiety or novelty response.

Prenatal stress (PS) induces long-lasting molecular alterations in brain circuits of the offspring and increases the propensity to develop neuropsychiatric diseases during adulthood, including mood disorders and drug addiction. A major goal of this study was to assess the impact of PS on pubertal behaviour and adult vulnerability to cocaine-induced conditioning place preference (CPP). We therefore evaluated pubertal novelty response and anxiety-like behaviour in control (C) and PS rats, and then, we examined cocaine-induced CPP in those animals during adulthood. We found no differences between C and PS groups on pubertal behaviour, however, only PS rats showed a significant cocaine-induced CPP. To further analyze our results, we classified cocaine-treated rats regarding their CPP score in Low CPP or High CPP and we then analysed their pubertal behaviour. We found different relations of anxiety-like behaviour to cocaine reward as a function of PS exposure: for C group, High CPP and Low CPP had shown similar levels of anxiety-like behaviour at puberty; on the contrary, for PS group, High CPP had shown lower anxiety-like behaviour than Low CPP rats. This study underscores the importance of considering prenatal exposure to stress when analysing the relationship between anxiety and cocaine vulnerability. Moreover, the evaluation of behavioural traits at puberty opens the possibility of early intervention and will allow the development of specific prevention strategies to avoid the devastating consequences of drug addiction later in life.

In Vivo and In Vitro Neuronal Plasticity Modulation by Epigenetic Regulators.

Prenatal stress (PS) induces molecular changes that alter neural connectivity, increasing the risk for neuropsychiatric disorders. Here we analyzed -in the hippocampus of adult rats exposed to PS- the epigenetic signature mediating the PS-induced neuroplasticity changes. Furthermore, using cultured hippocampal neurons, we investigated the effects on neuroplasticity of an epigenetic modulator. PS induced significant modifications in the mRNA levels of stress-related transcription factor MEF2A, SUV39H1 histone methyltransferase, and TET1 hydroxylase, indicating that PS modifies gene expression through chromatin remodeling. In in vitro analysis, histone acetylation inhibition with apicidin increased filopodium density, suggesting that the external regulation of acetylation levels might modulate neuronal morphology. These results offer a way to enhance neural connectivity that could be considered to revert PS effects.