Heterozygous deletion of the Williams-Beuren syndrome critical interval in mice recapitulates most features of the human disorder.

Williams-Beuren syndrome is a developmental multisystemic disorder caused by a recurrent 1.55-1.83 Mb heterozygous deletion on human chromosome band 7q11.23. Through chromosomal engineering with the cre-loxP system, we have generated mice with an almost complete deletion (CD) of the conserved syntenic region on chromosome 5G2. Heterozygous CD mice were viable, fertile and had a normal lifespan, while homozygotes were early embryonic lethal. Transcript levels of most deleted genes were reduced 50% in several tissues, consistent with gene dosage. Heterozygous mutant mice showed postnatal growth delay with reduced body weight and craniofacial abnormalities such as small mandible. The cardiovascular phenotype was only manifested with borderline hypertension, mildly increased arterial wall thickness and cardiac hypertrophy. The neurobehavioral phenotype revealed impairments in motor coordination, increased startle response to acoustic stimuli and hypersociability. Mutant mice showed a general reduction in brain weight. Cellular and histological abnormalities were present in the amygdala, cortex and hippocampus, including increased proportion of immature neurons. In summary, these mice recapitulate most crucial phenotypes of the human disorder, provide novel insights into the pathophysiological mechanisms of the disease such as the neural substrates of the behavioral manifestations, and will be valuable to evaluate novel therapeutic approaches.

Intracisternal Gtf2i Gene Therapy Ameliorates Deficits in Cognition and Synaptic Plasticity of a Mouse Model of Williams-Beuren Syndrome.

Williams-Beuren syndrome (WBS) is a neurodevelopmental disorder caused by a heterozygous deletion of 26-28 genes at chromosome band 7q11.23. Haploinsufficiency at GTF2I has been shown to play a major role in the neurobehavioral phenotype. By characterizing the neuronal architecture in four animal models with intragenic, partial, and complete deletions of the WBS critical interval (ΔGtf2i(+/-), ΔGtf2i( -/-), PD, and CD), we clarify the involvement of Gtf2i in neurocognitive features. All mutant mice showed hypersociability, impaired motor learning and coordination, and altered anxiety-like behavior. Dendritic length was decreased in the CA1 of ΔGtf2i(+/-), ΔGtf2i ( -/-), and CD mice. Spine density was reduced, and spines were shorter in ΔGtf2i ( -/-), PD, and CD mice. Overexpression of Pik3r1 and downregulation of Bdnf were observed in ΔGtf2i(+/-), PD, and CD mice. Intracisternal Gtf2i-gene therapy in CD mice using adeno-associated virus resulted in increased mGtf2i expression and normalization of Bdnf levels, along with beneficial effects in motor coordination, sociability, and anxiety, despite no significant changes in neuronal architecture. Our findings further indicate that Gtf2i haploinsufficiency plays an important role in the neurodevelopmental and cognitive abnormalities of WBS and that it is possible to rescue part of this neurocognitive phenotype by restoring Gtf2i expression levels in specific brain areas.

Metabolic abnormalities in Williams-Beuren syndrome.

BACKGROUND: Williams-Beuren syndrome (WBS, OMIM-194050) is a neurodevelopmental disorder with multisystemic manifestations caused by a 1.55-1.83 Mb deletion at 7q11.23 including 26-28 genes. Reported endocrine and metabolic abnormalities include transient hypercalcaemia of infancy, subclinical hypothyroidism in ∼ 30% of children and impaired glucose tolerance in ∼ 75% of adult individuals. The purpose of this study was to further study metabolic alterations in patients with WBS, as well as in several mouse models, to establish potential candidate genes. METHODS: We analysed several metabolic parameters in a cohort of 154 individuals with WBS (data available from 69 to 151 cases per parameter), as well as in several mouse models with complete and partial deletions of the orthologous WBS locus, and searched for causative genes and potential modifiers. RESULTS: Triglyceride plasma levels were significantly decreased in individuals with WBS while cholesterol levels were slightly decreased compared with controls. Hyperbilirubinemia, mostly unconjugated, was found in 18.3% of WBS cases and correlated with subclinical hypothyroidism and hypotriglyceridemia, suggesting common pathogenic mechanisms. Haploinsufficiency at MLXIPL and increased penetrance for hypomorphic alleles at the UGT1A1 gene promoter might underlie the lipid and bilirubin alterations. Other disturbances included increased protein and iron levels, as well as the known subclinical hypothyroidism and glucose intolerance. CONCLUSIONS: Our results show that several unreported biochemical alterations, related to haploinsufficiency for specific genes at 7q11.23, are relatively common in WBS. The early diagnosis, follow-up and management of these metabolic disturbances could prevent long-term complications in this disorder.

[Effectiveness of treatment with Pygeum africanum in patients with lower urinary tract symptoms and benign prostatic hyperplasia: a cross-sectional study in the real-world clinical practice in Spain (The PROFIT Study)]. / Efectividad del tratamiento con Pygeum africanum en pacientes con síntomas del tracto urinario inferior e hiperplasia benigna de próstata: estudio transversal en la práctica clínica real en España (Estudio PROFIT).

OBJECTIVES: To assess the effectivenessand tolerability of treatment with P africanum(P. africanum) in patients with lower urinary tractsymptoms (LUTS) associated with benign prostatichyperplasia (BPH) in routine clinical practice. MATERIAL AND METHODS: Cross-sectional observationalstudy in which 115 patients with LUTS/BPHtreated for 6 months with P. africanum (Tebetane® compuesto)in real-world clinical practice conditions wereincluded. The primary objective was to assess thequality of life (QoL) according to changes in the scoresof item 8 of the International Prostate Symptom Score(IPSS) questionnaire (a score ≥ 4 indicates a significantimpairment of QoL). Secondary objectives includedimprovement of urinary symptoms, urinary flow, satisfactionand compliance with treatment as well astolerability. Data were collected in a single scheduledvisit at 6 months of treatment with P. africanum andwere compared with data registered in the medicalrecords at the beginning of treatment. RESULTS: After 6 months of treatment withP. africanum, the percentage of patient with significantimpairment of QoL was 22.6% as compared with45.2% at the initiation of treatment (P 0,-001). Theoverall IPSS score showed a mean decreas of -4,-5points (median -4,0, interquartile range [IQR] -7,-0 to-2,0) and 69 patients (60%) showed a clinically significantimprovement (reduction of ≥ 4 points). Therewere significant decreases in IPSS subscales of storage(mean -1,-8; median -2,-0, IQR -3,-0 to 0 (P 0,-001)and voiding (mean -1,-9; median -2,-0, IQR -3,-0 to 0)(P 0,-001) symptoms. The degree of satisfaction and compliance with treatment was high with mean scores(median) of 6,9 (7,0) and 9,2 (10), respectively in the1-10 visual analogue scale. Treatment-related adverseeffects did not occur. CONCLUSIONS: Treatment with P. africanum during6 months improved significantly QoL and LUTS inpatients with BPH, with a high level of satisfaction andcompliance with treatment, without adverse events.

OBJETIVO: Evaluar la efectividad y latolerabilidad del tratamiento con Pygeum africanum (P.africanum) en pacientes con síntomas del tracto urinarioinferior (STUI) asociados a hiperplasia benigna depróstata (HBP) en la práctica clínica habitual.MATERIAL Y MÉTODOS: Estudio observacionaltransversal en el que se incluyeron 115 pacientes conSTUI/HBP tratados durante 6 meses con P. africanum (Tebetane® compuesto) en condiciones de prácticaclínica real. El objetivo primario fue evaluar la calidadde vida (CdV) en función del cambio en la pregunta 8del cuestionario de Puntuación Internacional de losSíntomas Prostáticos (IPSS) (puntuación ≥ 4 indicaafectación significativa de la CdV). Los objetivos secundariosincluyeron la mejoría de síntomas urinarios,flujo urinario, satisfacción y cumplimiento con eltratamiento, así como la tolerabilidad del mismo. Losdatos se recogieron en una única visita programada alos 6 meses de tratamiento con P. africanum y se compararoncon los registrados en la historia clínica alinicio del tratamiento. RESULTADOS: Tras 6 meses de tratamiento conP. africanum, el porcentaje de pacientes con afectaciónsignificativa de la CdV fue del 22,6% en comparacióncon un 45,2% al inicio del tratamiento (P 0,001).La puntuación global del IPSS disminuyó de mediaen -4,5 puntos (mediana -4,0, rango intercuartílico [RIQ] -7,0 a -2,0) y 69 pacientes (60%) mostraron unamejoría clínicamente significativa (disminución ≥ 4puntos). Se observaron disminuciones significativasen las subescalas del IPSS de los síntomas de llenado(media -1,8; mediana -2,0, RIQ -3,0 a 0) (P 0,001) yvaciado (media -1,9; mediana -2,0, RIQ -3,0 a 0) (P 0,001). El grado de satisfacción y cumplimiento con eltratamiento fue elevado con valores medios (mediana)de 6,9 (7,0) y 9,2 (10) respectivamente, en una escalaanalógica visual 1-10 cm. No se registraron efectosadversos relacionados con el tratamiento. CONCLUSION: El tratamiento con P. africanum(P. africanum) durante 6 meses mejoró significativamentela CdV y los STUI en pacientes con HBP, con unalto grado de satisfacción y cumplimiento con el tratamiento,sin registrarse reacciones adversas.

Epigallocatechin-3-gallate improves cardiac hypertrophy and short-term memory deficits in a Williams-Beuren syndrome mouse model.

Williams-Beuren syndrome (WBS) is a neurodevelopmental disorder caused by a heterozygous deletion of 26-28 genes at chromosome band 7q11.23. The complete deletion (CD) mouse model mimics the most common deletion found in WBS patients and recapitulates most neurologic features of the disorder along with some cardiovascular manifestations leading to significant cardiac hypertrophy with increased cardiomyocytes' size. Epigallocatechin-3-gallate (EGCG), the most abundant catechin found in green tea, has been associated with potential health benefits, both on cognition and cardiovascular phenotypes, through several mechanisms. We aimed to investigate the effects of green tea extracts on WBS-related phenotypes through a phase I clinical trial in mice. After feeding CD animals with green tea extracts dissolved in the drinking water, starting at three different time periods (prenatal, youth and adulthood), a set of behavioral tests and several anatomical, histological and molecular analyses were performed. Treatment resulted to be effective in the reduction of cardiac hypertrophy and was also able to ameliorate short-term memory deficits of CD mice. Taken together, these results suggest that EGCG might have a therapeutic and/or preventive role in the management of WBS.

Synaptic plasticity and spatial working memory are impaired in the CD mouse model of Williams-Beuren syndrome.

Mice heterozygous for a complete deletion (CD) equivalent to the most common deletion found in individuals with Williams-Beuren syndrome (WBS) recapitulate relevant features of the neurocognitive phenotype, such as hypersociability, along with some neuroanatomical alterations in specific brain areas. However, the pathophysiological mechanisms underlying these phenotypes still remain largely unknown. We have studied the synaptic function and cognition in CD mice using hippocampal slices and a behavioral test sensitive to hippocampal function. We have found that long-term potentiation (LTP) elicited by theta burst stimulation (TBS) was significantly impaired in hippocampal field CA1 of CD animals. This deficit might be associated with the observed alterations in spatial working memory. However, we did not detect changes in presynaptic function, LTP induction mechanisms or AMPA and NMDA receptor function. Reduced levels of Brain-derived neurotrophic factor (BDNF) were present in the CA1-CA3 hippocampal region of CD mice, which could account for LTP deficits in these mice. Taken together, these results suggest a defect of CA1 synapses in CD mice to sustain synaptic strength after stimulation. These data represent the first description of synaptic functional deficits in CD mice and further highlights the utility of the CD model to study the mechanisms underlying the WBS neurocognitive profile.

TFII-I regulates target genes in the PI-3K and TGF-ß signaling pathways through a novel DNA binding motif.

General transcription factor (TFII-I) is a multi-functional protein involved in the transcriptional regulation of critical developmental genes, encoded by the GTF2I gene located on chromosome 7q11.23. Haploinsufficiency at GTF2I has been shown to play a major role in the neurodevelopmental features of Williams-Beuren syndrome (WBS). Identification of genes regulated by TFII-I is thus critical to detect molecular determinants of WBS as well as to identify potential new targets for specific pharmacological interventions, which are currently absent. We performed a microarray screening for transcriptional targets of TFII-I in cortex and embryonic cells from Gtf2i mutant and wild-type mice. Candidate genes with altered expression were verified using real-time PCR. A novel motif shared by deregulated genes was found and chromatin immunoprecipitation assays in embryonic fibroblasts were used to document in vitro TFII-I binding to this motif in the promoter regions of deregulated genes. Interestingly, the PI3K and TGFß signaling pathways were over-represented among TFII-I-modulated genes. In this study we have found a highly conserved DNA element, common to a set of genes regulated by TFII-I, and identified and validated novel in vivo neuronal targets of this protein affecting the PI3K and TGFß signaling pathways. Overall, our data further contribute to unravel the complexity and variability of the different genetic programs orchestrated by TFII-I.