Phenotyping calcium and contraction in a zebrafish model of phospholamban R9C mutation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science, Innovation and Universities, Spain by Consejería de Educación, Cultura y Deportes. Junta de Comunidades de Castilla-La Mancha.

Background

Phospholamban regulates SERCA2a pump activity by reducing its calcium affinity in the heart. Under β-adrenergic stimulation, protein kinase A (PKA) phosphorylates phospholamban attenuating its inhibitory effect on SERCA2a. The phospholamban mutation Arg 9 to Cys (R9C) was firstly identified in an American family with ventricular dilatation and premature death, and subsequently in a cohort of dilated cardiomyopathy patients in South Africa. Emerging evidence suggests that phospholamban R9C is a loss-of-function mutation with autosomal dominant inheritance. In vitro studies revealed that it enhances pentamer assembly by disulfide bridge formation, reducing the availability of phospholamban monomers to regulate SERCA2a.

Purpose

The present study aimed to investigate defects in Ca2+ handling and cardiac function of phospholamban R9C mutation in an in vivo zebrafish model.

Methods

We generated transgenic zebrafish lines overexpressing phospholamban wild-type (TgPLNwt) and phospholamban R9C (TgPLNR9C) in the heart of zebrafish. To measure calcium kinetics in 3 day-old larvae, TgPLNwt and TgPLNR9C fish were outcrossed with transgenic zebrafish lines expressing the fluorescent calcium biosensor mCyRFP1-GCaMP6f (TgRFP-GcaMP6f) and the bioluminescence calcium biosensor GFP-Aequorin (TgGA) in the heart.

Results

Overexpression of phospholamban wild-type and R9C did not alter the heart rate compared to sibling larvae, and no differences were observed in the upstroke and recovery time of the calcium transients.  However, atrial and ventricular calcium transient amplitude were higher in TgPLNR9C larvae with respect to TgPLNwt larvae. Contractile force of the heart, assessed as the fractional shortening, increased in TgPLNR9C larvae compared to siblings and TgPLNwt. Furthermore, stroke volume and cardiac output were also higher in TgPLNR9C larvae. Bioluminescence experiments were performed to estimate the average calcium levels in the heart. We found that TgPLNR9C larvae showed higher calcium levels than sibling and TgPLNwt larvae. To evaluate the responsiveness to β-adrenergic stimulation, larvae were treated with the β-agonist isoproterenol. Calcium transient amplitude and contractile force increased in sibling and TgPLNwt larvae after treatment. However, this response was absent in TgPLNR9C larvae, suggesting that they were hyper-stimulated in basal conditions, displaying amplitude and contractile force similar to sibling and TgPLNwt larvae treated with isoproterenol.

Conclusion

TgPLNR9C larvae exhibited aberrant calcium handling in the heart with higher calcium levels and contractility, consistent with a lack of inhibition of SERCA2a. Consequently, TgPLNR9C larvae did not respond to β-adrenergic stimulation. These results were consistent with previous in vitro studies carried out in cardiomyocites infected with phospholamban R9C and highlighted the pathological defects of phospholamban R9C at early stages of the disease.

Comparison of developmental trauma between immigrant and non-immigrant psychotic patients

Introduction

Meta-analytic evidence suggests that migrants have higher risk for psychotic disorders. Likewise, growing evidence relate developmental trauma (emotional, sexual, physical abuse and neglect in childhood or adolescence) as a causal factor for psychotic symptoms. However, few studies examine developmental trauma in migrant populations.

Objectives

The aim of this study is to describe and compare developmental trauma exposure prevalence between immigrant and non-immigrant psychotic patients in Barcelona.

Methods

Patients who have presented, according DSM-V criteria, one or more non-affective psychotic episodes, were recruited in Acute and Chronic inpatients units at Hospital del Mar (Barcelona), leading to a total sample of 77 patients. Demographic characteristics of patients, clinical data and main pharmacological treatment were recorded through a questionnaire. Developmental trauma exposure was assessed by Childhood Trauma Questionnaire (CTQ). Comparative analysis was performed with IBM SPSS using Chi-Square Test and t-Student test.

Results

From a total of 77 patients, 43 were immigrants and 34 were non-immigrants. Exposure to traumatic events showed significant differences between immigrants and non-immigrant in Child emotional abuse (64,4% immigrants, 35,3% non-immigrant), Child physical abuse (51,2% immigrants, 14,7% non-immigrant), Child Sexual Abuse (41,9% immigrants, 11,8% non-immigrant) and physical neglect (62,8% immigrants, 26,5% non-immigrant). Emotional neglect exposure was no significant between both groups. Total mean CTQ score was 37,53 in immigrants group and 52,60 in non-immigrant group.

Conclusions

According to our results, there are important and significant differences in developmental trauma exposure between immigrant and non-immigrant psychotic patients. These results should be considered by clinicians in order to design assessment program for this population.

Disclosure

No significant relationships.

¿Do immigrant psychotic patients receive less psychotherapy assessment compared to non-immigrant psychotic patients?

Introduction

Migration is a highly defining life event which can lead to mental distress. It constitutes an overall risk factor for psychiatric disorders. However, psychotherapeutic treatment in immigrant patients is considered to be more complex, and the outcome appears to be less favorable than in patients without a migration background.

Objectives

The aim of this study is to compare psychotherapy assessment between immigrant and non-immigrant psychotic patients in Barcelona.

Methods

Patients who have presented, according DSM-V criteria, one or more non-affective psychotic episodes, were recruited in Acute and Chronic inpatients units at Hospital del Mar (Barcelona), leading to a total sample of 77 patients. Demographic characteristics of patients, clinical data and main pharmacological treatment were recorded through a questionnaire. Database information was completed with electronic medical records. Comparative analysis was performed with IBM SPSS using Chi-Square and t-Student test

Results

From a total of 77 patients, 43 were immigrants and 34 were non-immigrants. From the total immigrants only 30,2% received psychotherapy compared to 79,4% from the non-immigrants. The most prevalent therapy received in both groups was cognitive behavioural therapy. From the immigrants group only 2,3% received psychoeducation compared to 11,8% from the non-immigrant group.

Conclusions

According to our results, there are important and significant differences in psychotherapy assessment in migrant psychotic patients. In order to improve the mental health treatment of immigrant patients, the reasons for this poor outcome need to be investigated. These results should be considered by clinicians in order to design assessment program for this population.

Disclosure

No significant relationships.

Evaluation of machine learning algorithms and structural features for optimal MRI-based diagnostic prediction in psychosis

A relatively large number of studies have investigated the power of structural magnetic resonance imaging (sMRI) data to discriminate patients with schizophrenia from healthy controls. However, very few of them have also included patients with bipolar disorder, allowing the clinically relevant discrimination between both psychotic diagnostics. To assess the efficacy of sMRI data for diagnostic prediction in psychosis we objectively evaluated the discriminative power of a wide range of commonly used machine learning algorithms (ridge, lasso, elastic net and L0 norm regularized logistic regressions, a support vector classifier, regularized discriminant analysis, random forests and a Gaussian process classifier) on main sMRI features including grey and white matter voxel-based morphometry (VBM), vertex-based cortical thickness and volume, region of interest volumetric measures and wavelet-based morphometry (WBM) maps. All possible combinations of algorithms and data features were considered in pairwise classifications of matched samples of healthy controls (N = 127), patients with schizophrenia (N = 128) and patients with bipolar disorder (N = 128). Results show that the selection of feature type is important, with grey matter VBM (without data reduction) delivering the best diagnostic prediction rates (averaging over classifiers: schizophrenia vs. healthy 75%, bipolar disorder vs. healthy 63% and schizophrenia vs. bipolar disorder 62%) whereas algorithms usually yielded very similar results. Indeed, those grey matter VBM accuracy rates were not even improved by combining all feature types in a single prediction model. Further multi-class classifications considering the three groups simultaneously made evident a lack of predictive power for the bipolar group, probably due to its intermediate anatomical features, located between those observed in healthy controls and those found in patients with schizophrenia. Finally, we provide MRIPredict (https://www.nitrc.org/projects/mripredict/), a free tool for SPM, FSL and R, to easily carry out voxelwise predictions based on VBM images.

[Systematic review of the Genomewide Association Studies (GWAS) in schizophrenia]

INTRODUCTION

Heritability in schizophrenia can reach up to 80% and the risk in families is 5-10 times higher than in the general population. The large contribution of genetics in this disorder has led to a growing interest in its study.

OBJECTIVES

To review the findings of genetic studies known as Genomewide Association Studies (GWAS) on schizophrenia.

METHOD

Systematic search using Pubmed with the key words GWAS and (psychosis) or (schizophrenia). The following web pages have been reviewed: http://www.szgene.org/largescale.asp and www.genome.gov/gwastudies/.

RESULTS

The GWAS have focused on causal biological aspects, such as the histocompatibility complex, glutamate metabolism, apoptosis and inflammatory processes, and the immune system (TNF-β, TNFR1). Also focused in the search were the genes that modulate the appearance of secondary metabolic and cardiac effects and secondary effects in subjects with schizophrenia and on anti-psychotic treatment. In neurorecognition, over-expression of the MET proto-oncogene (MET) has been associated with a low susceptibility for schizophrenia and a better cognitive performance, as well as a lower susceptibility for the incidence of cancer. Mention is also made of the different genes that mediate in cognitive functioning depending on the anti-psychotic treatment received.

CONCLUSIONS

The main interests of the GWAS during the last few years have been the neurobiological pathways involved in schizophrenia. The discoveries arising from these studies have been limited. This has led to an innovative approach on the aetiological study of the disorder by studying gene-environment interactions.

Past, present and future of newborn screening in Chile

The history of the Newborn Screening Program in Chile begins in 1984, when a pilot plan was developed that demonstrated the feasibility of its implementation. In 1992, the Ministry of Health started a national newborn screening program for phenylketonuria (PKU) and congenital hypothyroidism (CH), and in 1998, this was extended to the entire country. Throughout this period, a total of 2,478,123 newborns (NB) have been analyzed, obtaining initial coverage of 48.8%, which was later increased to 87.7%, and at present it is at 98.7% of all NB of our country. During this period, 131 cases with PKU have been diagnosed, resulting in an incidence of 1:18,916 NB, an average age of diagnosis of 18 ± 10.2 days and average phenylalanine level of 19,9 ± 8.8 mg/dl. In relation to CH, 783 cases have been confirmed, arriving at an incidence of 1:3,163 NB, with average age of diagnosis of 12.5 ± 6.9 days. Due to the good results of the program, the government is evaluating the initiation of an extended pilot program, to introduce other pathologies.

[Experience and results of acute lymphoblastic leukaemia treatment in children between 1989-2005 in Navarre]

BACKGROUND

The determination of prognostic factors in acute lymphoblastic leukaemia (ALL) is increasingly important in establishing a correct treatment. We analyse the overall survival (OS), event free survival (EFS) and prognostic factors in our 16 years experience of treating acute lymphoblastic leukaemia.

METHODS

We performed univariate and multivariate analyses of the prognostic factors we considered most significant in our serie of patients.

RESULTS

From January 1989 to December 2005, 50 cases of ALL were reported in 58 patients with LA. We analysed a subgroup of 41 patients with LLA as they were included in standard protocols. In this group the EFS was 78% and OS 87.8%. Inmunophenotype is a predictor of prognosis when we compare Common with Others, with a HR of 13.82 (CI95%: 1.019-166.008) p<0.05; Protocol of Treatment of the Paediatric Haematology Oncology Society (SHOP) (94-99/89) with HR of 0.065 (CI95%: 0.005-0.008) p<0.02; and Age (>120 months/12-120 months) with a HR of 13.82 (CI95%: 0.58-329.48) p=0.1.

CONCLUSIONS

The OS in our series is similar to that reported in the literature. Inmunophenotype and protocols of treatment are the most significant prognostic factors.

[Genetic mechanisms in the hereditary predisposition to colorectal cancer]

A proportion of colorectal cancers shows some type of genetic predisposition that can be recognised in clinical practice. From the classical dominant inheritance pattern of familial adenomatous polyposis or hereditary non-polyposis colorectal cancer, through the recessive transmission of the MYH associated polyposis, to the new syndromes of the "serrated pathway" or low-penetrance alleles, the discovery of new genes and a deeper understanding of the mechanisms of action of already-known ones are enabling us to understand new aspects of the colorectal carcinogenesis. This is throwing a new light on some of the observed familial aggregation patterns which had remained unexplained.

Incidence and mutation rates of Huntington's disease in Spain: experience of 9 years of direct genetic testing

BACKGROUND

Prior to the discovery of the Huntington's disease (HD) mutation, the prevalence, incidence, and new mutation rates for this disease were based on the presence of progressive choreic movements and a positive family history.

OBJECTIVE

To evaluate the uptake of the HD genetic analysis in Spain, and to provide additional information on the epidemiology of this disease from the experience of 9 years of direct genetic testing.

METHODS

From 1994 to 2002, CAG repeat length was determined in 317 patients with symptoms compatible with HD. In all cases, demographic, clinical, and family data were carefully reviewed.

RESULTS

HD diagnosis (CAG repeat length >/=36) was confirmed in 166 (52%) symptomatic cases. Of these, 76 (45.8%) reported a positive family history and in 21 cases (12.7%) family history was negative. New mutation events were genetically proven in three families and highly suspected in another, estimating that the minimum new mutation rate for HD in our population is >4%, with a potential mutation rate of 8%. More than 16% of all HD cases had late onset (>59 years) of symptoms, and in three quarters of these the family history was negative. The incidence rate for the autonomous communities of Navarra and the Basque country, based on the number of newly diagnosed cases by genetic testing, was 4.7 per million per year.

CONCLUSIONS

Direct HD genetic testing shows that the incidence and mutation rates of the disease are 2-3 times higher than previously reported. We also demonstrated the relevance of CAG repeat length assessment in diagnosing patients with late onset of symptoms and negative family history for HD.

[Updating Fanconi's anaemia]

Fanconi's anaemia (FA) is an autosomal recessive syndrome associated with chromosomal instability, and hypersensitivity of the DNA to claustrogenic agents. Clinically it presents a progressive marrow insufficiency, different congenital anomalies and an predisposition to malignancy. Eight complementation groups have been defined and the genes corresponding to six of them have been cloned. Recent advances in molecular biology have made it possible to investigate the relationship between the FA genotype and the nature and severity of the clinical phenotype. The treatment of FA is also the object of intense research that is currently centred on the transplant of hematopoyetic progenitors, especially successful in cases of an HLA-identical brother or sister donor, and in gene therapy, which is still in the phase of clinical research.

Heat-shock protein 70-1 and HLA class II gene polymorphisms associated with celiac disease susceptibility in Navarra (Spain)

Heat shock proteins (HSP) are thought to play a role in the immune response making probable their contribution to celiac disease (CD). We studied the polymorphisms in the 5' regulatory region of the HSP70-1 gene and performed genomic HLA-DQ and -DR typing in 128 CD patients and 94 healthy controls from Navarra (Spain). The frequency of the C allele of the HSP70-1, characterized by the intermediate electrophoretic mobility of DNA, was significantly increased among CD patients (64.5% vs 37.2%. p <1 x 10(-7)). When subjects were stratified by the HLA II genotype, differences were statistically significant between DR3-negative or DR3-DQB1*02-negative CD patients and matched controls. Homozygosity for the DQB1*02 allele was present in 48.4% of CD patients and 12.8% of controls (OR = 6.4; CI:3.1 to 13.8; p <1 x 10(-7)). Similar increased risk was observed for DQB1*02/*02, DRB1*03/-, or DRB1*03/07 patients. Furthermore, those individuals expressing the classical HLA alleles in CD (DQB1*02/*02, DRB1*03/*07) who also carried the HSP70-1 CC genotype were twelve times more likely to develop the disease than the matched controls. We therefore conclude that although HSP70-1 gene does not seem to be primarily associated with CD, it might be a component of the high risk haplotype, playing a role as an additional predisposing gene for the disease.

Familial choanal atresia with maxillary hypoplasia, prognathism, and hypodontia

We report on two sibs and a cousin with bilateral choanal atresia. At 2 months, one sib died of complications following surgical correction of her defects. We evaluated her brother and cousin at age 7 and 9 years, respectively. Both had a tall forehead, maxillary hypoplasia, prognathism, and absence of certain deciduous and permanent teeth. Psychomotor development was appropriate for age. Roentgenocephalometric analyses of several relatives showed that one grandfather of these children and two of the five uncles and aunts also had maxillary hypoplasia and/or prognathism. To our knowledge, this condition has not been described previously and may represent a newly recognized autosomal dominant condition with incomplete penetrance and variable expressivity caused by a defect of neural crest development.

[Direct molecular analysis of FMR-1 gene mutation in patients with fragile Xq syndrome and their families]

BACKGROUND

The unequivocal diagnosis of fragile Xq syndrome is based in the direct analysis of the underlying FMR-1 gene mutation, that consists in an increased number of trinucleotide CGG repetitions.

AIM

To study families with fragile Xq syndrome, using the Southern technique for the analysis of the mutation.

SUBJECTS AND METHODS

Fifteen individuals, pertaining to 6 families with fragile Xq syndrome, were studied. Clinical, cytogenetic and molecular analysis using Southern technique, were done.

RESULTS

Five male individuals had a clinically evident syndrome, confirmed by cytogenetic analysis that showed fragility in 10 to 29% of studied cells. One subject with a clinical picture suggesting fragile Xq had a normal cytogenetic study. The other studied subjects were the mothers of the five subjects with the syndrome, that must be carriers, and four brothers. Molecular analysis showed that seven subjects (5 males) had a complete mutation, five (4 females) were carriers of a pre mutation and three (2 males) did not have the mutation.

CONCLUSIONS

The Southern technique allows to verify the normal condition of FRAXA locus, identify carriers and to detect complete mutations in fragile Xq syndrome.

[Epidemiology of neurosensorial deafness in the Foral Community of Navarra]

Congenital deafness is a relatively frequent disorder that shows a heterogeneous aetiology. Knowledge and the control of some risk factors have decreased the incidence of acquired deafness and increased the relative importance of genetic cause. In an attempt to investigate the clinical relevance of congenital deafness and the mechanisms of prevention in our population, a clinical and genetic study of cases with neurosensorial deafness born in Navarra between 1975 and 1990 was carried out. A total of eighty-one cases were identified, giving an incidence of 0.8 per thousand. Thirty per cent of the cases showed deafness associated with defects. Cause of deafness was identified in seventy per cent of the cases with whom a detailed clinical and genetic study could be performed (n=50). Genetic factors were responsible for the disorder in more than half of these cases. The most frequent hereditary factor was of the autosomic recessive type. This was associated with a more severe form of hearing loss.

Further delineation of pseudotrisomy 13 syndrome: a case without polydactyly

We report on a baby with holoprosencephaly, median cleft lip, cardiac and genital anomalies, normal upper limbs, and a 46,XX karyotype. We also reviewed 22 karyotypically normal cases whose clinical features resembled trisomy 13 syndrome and compared them with the case we present. The problem of variable expression of the pseudotrisomy 13 syndrome versus genetic heterogeneity is illustrated.

[Philadelphia-positive ALL with rearrangement of the 1st intron of the BCR gene]

We have studied the haematologic, cytogenetic and molecular features in a patient with Ph positive ALL. The cytogenetic study showed the presence of a Ph chromosome since diagnosis. Molecular analysis showed rearrangement within the first intron of bcr gen instead of M-bcr as in CML. This an evidence of genic fusion between c-abl oncogene and bcr gene and also show the possibility of rearrangement outside M-bcr in these patients.

[Demonstration of BCR-ABL rearrangement in a patient with apparently Ph-negative chronic myeloid leukemia of 15 years' duration]

We have studied the haematologic cytogenetic and molecular features in a patient with Ph negative CML of 15 years of evolution. Cytogenetic analysis showed a normal karyotype in different studies. Molecular study showed rearrangement within bcr region. This gene fusion between c-abl oncogene and bcr gene is typical of the Ph chromosome. These results show the usefulness of performing a molecular study in those patients with Ph negative CML.

[Molecular analysis in 13 cases of chronic Philadelphia-positive myeloid leukemia]

Thirteen cases of Ph-positive CML have been studied from a cytogenetic and molecular point of view. All cases had Ph chromosome identified as t(9;22). Three of these cases were in blast crisis, and additional alterations to the Ph chromosome were found. The molecular study was made using the 3'bcr probe to analyze the ability to detect the translocation at the molecular level in bone marrow, peripheral blood, other tissues and in cases with mosaicism. Likewise we have evaluated the possibility to obtain molecular results from Carnoy-fixed samples which have been previously used in cytogenetic studies. In all cases we have detected rearrangement in the bcr region; this shows the interest and usefulness of this new methodology in the study of CML in different situations.