Assignment of IVL-Methyl side chain of the ligand-free monomeric human MALT1 paracaspase-IgL3 domain in solution

Mucosa-associated lymphoid tissue protein 1 (MALT1) plays a key role in adaptive immune responses by modulating specific intracellular signalling pathways that control the development and proliferation of both T and B cells. Dysfunction of these pathways is coupled to the progress of highly aggressive lymphoma as well as to potential development of an array of different immune disorders. In contrast to other signalling mediators, MALT1 is not only activated through the formation of the CBM complex together with the proteins CARMA1 and Bcl10, but also by acting as a protease that cleaves multiple substrates to promote lymphocyte proliferation and survival via the NF-κB signalling pathway. Herein, we present the partial ¹H, ¹³C Ile/Val/Leu-Methyl resonance assignment of the monomeric apo form of the paracaspase-IgL₃ domain of human MALT1. Our results provide a solid ground for future elucidation of both the three-dimensional structure and the dynamics of MALT1, key for adequate development of inhibitors, and a thorough molecular understanding of its function(s).

Effects of serum branched-chain amino acids on nonalcoholic fatty liver disease and subsequent cardiovascular disease

BACKGROUND

To reveal the role of branched-chain amino acids (BCAAs) in the development and progression of nonalcoholic fatty liver disease (NAFLD) and the effect on the incidence of subsequent cardiovascular disease.

METHODS

A total of 1302 subjects in the cohort study of the Huai'an Diabetes Prevention Program were divided into two groups according to whether NAFLD was present at baseline. The group without NAFLD at baseline was only followed up, and the group with NAFLD at baseline received diet and exercise interventions. Anthropometric and biochemical examinations were performed at baseline and at the end of 4 years for all subjects. Serum BCAA (leucine, isoleucine, and valine) levels were measured by hydrophilic interaction chromatography-tandem mass spectrometry. The associations of baseline serum BCAA levels with the risk for NAFLD, coronary heart disease (CHD), and cardiovascular events (CVEs) after 4 years were further evaluated.

RESULTS

(1) At baseline and after the 4-year follow-up, baseline serum leucine, valine, and total BCAAs in the NAFLD group were significantly higher than those in the non-NAFLD group (p < 0.05). (2) According to whether NAFLD was present at baseline and after follow-up, all subjects were divided into four groups, including the control group, new case group, improvement group, and unchanged group. There was no significant difference in baseline BCAAs levels between the new case group and the improvement group (p > 0.05). (3) Risk factors for the occurrence and development of NAFLD were analysed by a multiple logistic regression model according to whether NAFLD existed at baseline. Serum leucine (OR = 1.058, 95% CI 1.005-1.114, p = 0.033) and total BCAAs (OR = 1.023, 95% CI 1.001-1.046, p = 0.045) were independent risk factors for new-onset NAFLD. Serum valine (OR = 1.131, 95% CI 1.043-1.226, p = 0.003), and total BCAAs (OR = 1.040, 95% CI 1.003-1.078, p = 0.035) were independent risk factors showing that NAFLD could not be reversed. (4) The cross-table Chi-square test showed that the incidence of both CHD and CVEs was significantly highest in the new case group (p < 0.05). (5) After adjusting for confounding factors, baseline isoleucine, valine, and BCAA levels were independently associated with new-onset CHD in subjects with or without NAFLD at baseline (p < 0.05).

CONCLUSIONS

High BCAA levels exacerbate the risk of CHD and CVEs by influencing the occurrence and progression of NAFLD. However, lifestyle interventions could reverse the risk of NAFLD, CHD and CVEs associated with BCAAs.

Blood coagulation factor XIII-A subunit Val34Leu polymorphisms and intracerebral hemorrhage risk: A meta-analysis of case-control studies

BACKGROUND

Previous studies investigating the association between factor XIII-A subunit (FXIII-A) Val34Leu polymorphisms and intracerebral hemorrhage (ICH) had provided inconsistent results and no large systematic review or meta-analysis had been conducted regarding this issue.

METHODS

We conducted a meta-analysis to confirm whether the FXIII-A Val34Leu polymorphisms increased the risk of ICH. Relevant studies were identified from the Pubmed, Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases published up to September 2013. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for FXIII-A Val34Leu polymorphisms and ICH were calculated in a fixed-effects model or a random-effects model when appropriate. We also carried out the stratified analyses and sensitivity analyses by region, source of control group, and sample size.

RESULTS

Eight eligible studies were reviewed. As FXIII Val34Leu was absent or had a very low prevalence among East Asians, only six studies in Caucasians were analyzed, involving 564 cases and 1276 controls. Overall, the Leu allele of FXIII gene had a trend to slightly increased odds of having ICH, but there is no statistic significance (OR1.23, 95% CI 0.94-1.61, P = 0.13). The OR of genotypes Leu+(Leu/Leu or Leu/Val) for the risk of ICH was 1.21, 95% CI 0.98-1.50, P = 0.08. And the OR of recessive model genotypes was 1.53, 95% CI 0.81-2.88, P = 0.19. There was no difference of the association between the Leu allele of FXIII gene and risk of ICH in stratified analysis.

CONCLUSIONS

Our meta-analysis suggests that there is no evidence for strong association between FXIII Val34Leu polymorphisms and ICH, but Leu allele of FXIII gene might slightly increase the risk of ICH in Caucasians. Since limited studies and subjects were included, larger scale association studies exploring the gene-gene interactions and gene-environment interactions are necessary to further validate the association.

Stress and neurodevelopmental processes in the emergence of psychosis

The notion that stress plays a role in the etiology of psychotic disorders, especially schizophrenia, is longstanding. However, it is only in recent years that the potential neural mechanisms mediating this effect have come into sharper focus. The introduction of more sophisticated models of the interplay between psychosocial factors and brain function has expanded our opportunities for conceptualizing more detailed psychobiological models of stress in psychosis. Further, scientific advances in our understanding of adolescent brain development have shed light on a pivotal question that has challenged researchers; namely, why the first episode of psychosis typically occurs in late adolescence/young adulthood. In this paper, we begin by reviewing the evidence supporting associations between psychosocial stress and psychosis in diagnosed patients as well as individuals at clinical high risk for psychosis. We then discuss biological stress systems and examine changes that precede and follow psychosis onset. Next, research findings on structural and functional brain characteristics associated with psychosis are presented; these findings suggest that normal adolescent neuromaturational processes may go awry, thereby setting the stage for the emergence of psychotic syndromes. Finally, a model of neural mechanisms underlying the pathogenesis of psychosis is presented and directions for future research strategies are explored.

RNF43 mutations are recurrent in Chinese patients with mucinous ovarian carcinoma but absent in other subtypes of ovarian cancer

Ring finger protein 43 (RNF43) is an E3 ubiquitin-protein ligase that accepts ubiquitin from an E2 ubiquitin-conjugating enzyme and directly transfers the ubiquitin to targeted substrate proteins. Recently, large-scale sequencing efforts have identified prevalent RNF43 mutations in pancreatic and ovarian mucinous carcinomas. In the present study, we sequenced the entire coding sequences of RNF43 in 251 Chinese patients with distinct subtypes of ovarian cancers for the presence of RNF43 mutations. A total of 2 novel heterozygous nonsynonymous RNF43 mutations were identified in 2 out of 15 (13.3%) patients with mucinous ovarian carcinoma, these mutations were evolutionarily highly conserved; while no mutation was detected in other samples. In addition, none of the RNF43-mutated samples harbored DICER1 (dicer 1, ribonuclease type III), PPP2R1A (protein phosphatase 2, regulatory subunit A, alpha), TRRAP (transformation/transcription domain-associated protein) and DNMT3A (DNA (cytosine-5-)-methyltransferase 3 alpha) hot-spot mutations. Recurrent RNF43 mutations existed in mucinous ovarian carcinomas implicated that these mutations might play crucial roles in the tumorigenesis of these patients, while the absence of DICER1, PPP2R1A, TRRAP and DNMT3A hot-spot mutations suggested that these genetic alterations might not play synergistic roles with RNF43 mutations in these individuals. Additionally, the absence of RNF43 mutations in other subtypes of ovarian carcinoma implicated that RNF43 mutations might not be actively involved in the pathogenesis of these disorders.

BDNF Val66Met variants and brain volume changes in non-affective psychosis patients and healthy controls: a 3 year follow-up study

INTRODUCTION

Functional gene polymorphisms modulating neuroplasticity might mediate brain longitudinal structural changes in schizophrenia. The present study aimed to explore possible effects of BDNF Val66Met polymorphism variations on progressive structural brain changes after 3 years from the first episode of psychosis.

METHOD

Patients were part of a large epidemiological and longitudinal intervention program of first-episode psychosis, carried out at the University Hospital Marqués de Valdecilla, Cantabria, Spain. Eighty first-episode patients and 54 healthy controls were included in the final analyses. Brain magnetic resonance imaging (baseline and 3-year follow-up) and BDNF genotype, and clinical and functional outcome were investigated.

RESULTS

We did not detect significant association between brain changes and BDNF Val66Met polymorphism variations in patients and controls (all p>0.060). At baseline, there were no significant associations between brain anomalies and BDNF genotype. Functional deficits were similar in Met-carrier and Val homozygote patients after 3-year follow-up (X(2) = 0.66; p = 0.564); there was no relationship between significant volume change across time and functional outcome. Otherwise, Met-carrier controls had significant high rates of alcohol-consumption (p = 0.019) compared to Val homozygote controls.

CONCLUSION

Our findings do not support the notion that BDNF genotype variations may mediate brain macroscopic morphological changes across time.

Rapid and sensitive ultrasonic-assisted derivatisation microextraction (UDME) technique for bitter taste-free amino acids (FAA) study by HPLC-FLD

Amino acids, as the main contributors to taste, are usually found in relatively high levels in bitter foods. In this work, we focused on seeking a rapid, sensitive and simple method to determine FAA for large batches of micro-samples and to explore the relationship between FAA and bitterness. Overall condition optimisation indicated that the new UDME technique offered higher derivatisation yields and extraction efficiencies than traditional methods. Only 35min was needed in the whole operation process. Very low LLOQ (Lower limit of quantification: 0.21-5.43nmol/L) for FAA in twelve bitter foods was obtained, with which BTT (bitter taste thresholds) and CABT (content of FAA at BTT level) were newly determined. The ratio of CABT to BTT increased with decreasing of BTT. This work provided powerful potential for the high-throughput trace analysis of micro-sample and also a methodology to study the relationship between the chemical constituents and the taste.

Citron and lemon under the lens of HR-MAS NMR spectroscopy

High Resolution Magic Angle Spinning (HR-MAS) is an NMR technique that can be applied to semi-solid samples. Flavedo, albedo, pulp, seeds, and oil gland content of lemon and citron were studied through HR-MAS NMR spectroscopy, which was used directly on intact tissue specimens without any physicochemical manipulation. HR-MAS NMR proved to be a very suitable technique for detecting terpenes, sugars, organic acids, aminoacids and osmolites. It is valuable in observing changes in sugars, principal organic acids (mainly citric and malic) and ethanol contents of pulp specimens and this strongly point to its use to follow fruit ripening, or commercial assessment of fruit maturity. HR-MAS NMR was also used to derive the molar percentage of fatty acid components of lipids in seeds, which can change depending on the Citrus species and varieties. Finally, this technique was employed to elucidate the metabolic profile of mold flavedo.

Translational developmental studies of stress on brain and behavior: implications for adolescent mental health and illness?

Adolescence is the transition from childhood to adulthood, with onset marked by puberty and the offset by relative independence from parents. Across species, it is a time of incredible change that carries increased risks and rewards. The ability of the individual to respond adequately to the mental, physical and emotional stresses of life during this time is a function of both their early environment and their present state. In this article, we focus on the effects that acute threat and chronic stress have on the brain and behavior in humans and rodents. First, we highlight developmental changes in frontolimbic function as healthy individuals transition into and out of adolescence. Second, we examine genetic factors that may enhance susceptibility to stress in one individual over another using translation from genetic mouse models to human neuroimaging. Third, we examine how the timing and nature of stress varies in its impact on brain and behavior. These findings are discussed in the context of implications for adolescent mental health and illness.

Characterization of 2-(methylamino)alkanoic acid capacity to restrict blood-brain phenylalanine transport in Pah enu2 mice: preliminary findings

BACKGROUND

Our laboratory seeks a pharmacotherapeutic intervention for PKU that utilizes non-physiological amino acids (NPAAs) to block the accumulation of phenylalanine (Phe) in the brain. In previous studies (Vogel et al. 2013), methylation of the amino group of 2-aminoisobutyrate (AIB) provided an enhanced degree of selectivity for Phe restriction into the brain of Pah(enu2) mice in comparison to unmethylated AIB, leading to the hypothesis that 2-(methylamino)alkanoic acid analogs of AIB might represent targeted inhibitors of Phe accretion into the brain.

METHODS

Pah(enu2) and control mice were intraperitoneally administered (500-750 mg/kg body weight, once daily; standard 19% protein diet) AIB, methyl AIB (MAIB), isovaline, and two MAIB analogs, 2-methyl-2-(methylamino)butanoic (MeVal) and 3-methyl-2-(methylamino)pentanoic (MePent) acids for one week, followed by brain and blood isolation for amino acid analyses using UPLC.

RESULTS

In the brain, AIB significantly reduced Phe accretion in Pah(enu2) mice, while MeVal significantly improved glutamine and aspartic acids. Four of five test compounds improved brain threonine and arginine levels. AIB, MAIB and IsoVal significantly reduced blood Phe, with no effect of any drug intervention on other sera amino acids.

CONCLUSIONS

Further evaluation of AIB and the 2-(methylamino)alkanoic acids as inhibitors of brain Phe accumulation in Pah(enu2) mice is warranted, with more detailed evaluations of route of administration, combinatorial intervention, and detailed toxicity studies.