Glyoxylase-1 combats dicarbonyl stress and right ventricular dysfunction in rodent pulmonary arterial hypertension.

Background: Heightened glycolytic flux is associated with right ventricular (RV) dysfunction in pulmonary arterial hypertension (PAH). Methylglyoxal, a glycolysis byproduct, is a highly reactive dicarbonyl that has toxic effects via non-enzymatic post-translational modifications (protein glycation). Methylglyoxal is degraded by the glyoxylase system, which includes the rate-limiting enzyme glyoxylase-1 (GLO1), to combat dicarbonyl stress. However, the potential consequences of excess protein glycation on RV function are unknown. Methods: Bioinformatics analysis of previously identified glycated proteins predicted how protein glycation regulated cardiac biology. Methylglyoxal treatment of H9c2 cardiomyocytes evaluated the consequences of excess protein glycation on mitochondrial respiration. The effects of adeno-associated virus serotype 9-mediated (AAV9) GLO1 expression on RV function in monocrotaline rats were quantified with echocardiography and hemodynamic studies. Immunoblots and immunofluorescence were implemented to probe the effects of AAV-Glo1 on total protein glycation and fatty acid oxidation (FAO) and fatty acid binding protein levels. Results: In silico analyses highlighted multiple mitochondrial metabolic pathways may be affected by protein glycation. Exogenous methylglyoxal minimally altered mitochondrial respiration when cells metabolized glucose, however methylglyoxal depressed FAO. AAV9-Glo1 increased RV cardiomyocyte GLO1 expression, reduced total protein glycation, partially restored mitochondrial density, and decreased lipid accumulation. In addition, AAV9-Glo1 increased RV levels of FABP4, a fatty acid binding protein, and hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunits alpha and beta (HADHA and HADHB), the two subunits of the mitochondrial trifunctional protein for FAO. Finally, AAV9-Glo1 blunted RV fibrosis and improved RV systolic and diastolic function. Conclusion: Excess protein glycation promotes RV dysfunction in preclinical PAH, potentially through suppression of FAO.

Shifting gears: the search for group 3 pulmonary hypertension treatment.

PURPOSE OF REVIEW: Treatment options for Group 3 pulmonary hypertension, characterized as secondary to chronic hypoxia or lung disease, remain an elusive holy grail for physicians and patients alike. Despite increasing identification and investigation into this pulmonary vasculopathy group with the second-highest frequency and highest mortality, there are no therapeutic interventions that offer the significant improvements in morbidity and mortality comparable to those benefiting other pulmonary hypertension groups including pulmonary arterial hypertension. This review examines the data on available and emerging Group 3 pulmonary hypertension treatments. RECENT FINDINGS: Pulmonary vasodilators have yielded equivocal results in this patient population, although recent evidence shows modestly improved outcomes with inhaled treprostinil in interstitial lung disease-associated pulmonary hypertension. With pulmonary vasodilators providing limited benefit, emerging data support the right ventricle as a potential treatment target in Group 3 pulmonary hypertension. SUMMARY: Group 3 pulmonary hypertension is associated with significant morbidity and mortality. Pulmonary vasodilators offer only limited haemodynamic and exertional benefits, and lung transplantation remains the only cure for this deadly disease. The right ventricle may provide a novel intervention target.

Sex Differences in Right Ventricular Dysfunction: Insights From the Bench to Bedside.

There are inherent distinctions in right ventricular (RV) performance based on sex as females have better RV function than males. These differences are magnified and have very important prognostic implications in two RV-centric diseases, pulmonary hypertension (PH), and arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). In both PH and ARVC/D, RV dysfunction results in poor patient outcomes. However, there are no currently approved therapies specifically targeting the failing RV, an important unmet need for these two life-threatening disorders. In this review, we highlight human data demonstrating divergent RV phenotypes in healthy, PH, and ARVC/D patients based on sex. Furthermore, we discuss the links between estrogen (the female predominant sex hormone), testosterone (the male predominant sex hormone), and dehydroepiandrosterone (a precursor hormone for multiple sex hormones in males and females) and RV function in both disorders. To provide potential mechanistic insights into sex differences in RV function, we review data that investigate how sex hormones combat or contribute to pathophysiological changes in the RV. Finally, we highlight the ongoing clinical trials in pulmonary arterial hypertension targeting estrogen and dehydroepiandrosterone signaling. Hopefully, a greater understanding of the factors that promote superior RV function in females will lead to novel therapeutic approaches to combat RV dysfunction in PH and ARVC/D.

"Building strength in coming together": A mixed methods study using the arts to explore smoking with staff working in Indigenous tobacco control.

ISSUE ADDRESSED: Tobacco is a major risk factor contributing to Indigenous health disparities. Art may be a powerful and transformative tool to enable health providers to develop targeted messages for tobacco control. METHODS: Indigenous and non-Indigenous staff, working in Indigenous tobacco control, attended a 2-hour workshop, and were led through a process to create individual artworks. Participants completed surveys before and after the workshop. Scales compared understandings of how art can be used in tobacco control, and the likelihood of utilising arts in future programs. Three pairs of Indigenous and non-Indigenous researchers analysed the artworks, using the Four Frames (New South Wales Board of Studies), explored themes, and developed a model. RESULTS: Nineteen participants completed both surveys; 17 artworks were analysed. Pre- to post-workshop increases in "understanding" about the use of arts (P < 0.00001) for tobacco control, and "likelihood" of use of arts in the next 6 months (P < 0.006) were significant. Participants expressed personal and professional benefits from the workshop. Artworks demonstrated themes of optimism, the strength of family and culture, smoking as a barrier, resilience, recovery and urgency. CONCLUSIONS: The workshop increased the understanding and likelihood of using the arts for tobacco control. Artworks revealed contemporary challenges impacting on equity; health staff expressed optimism for being engaged in their work. SO WHAT?: The Framework Convention for Tobacco Control supports novel techniques to increase the reach and relevance of health messages for diverse populations. This study successfully demonstrated how a novel, positively framed art-based technique proved to be advantageous for health professionals, working in an area of Indigenous tobacco control, where behavioural change can be complex.

Engineering the expression of an anti-interleukin-13 antibody through rational design and mutagenesis.

High levels of protein expression are key to the successful development and manufacture of a therapeutic antibody. Here, we describe two related antibodies, Ab001 and Ab008, where Ab001 shows a markedly lower level of expression relative to Ab008 when stably expressed in Chinese hamster ovary cells. We use single-gene expression vectors and structural analysis to show that the reduced titer is associated with the VL CDR2 of Ab001. We adopted two approaches to improve the expression of Ab001. First, we used mutagenesis to change single amino-acid residues in the Ab001 VL back to the equivalent Ab008 residues but this resulted in limited improvements in expression. In contrast when we used an in silico structure-based design approach to generate a set of five individual single-point variants in a discrete region of the VL, all exhibited significantly improved expression relative to Ab001. The most successful of these, D53N, exhibited a 25-fold increase in stable transfectants relative to Ab001. The functional potency of these VL-modified antibodies was unaffected. We expect that this in silico engineering strategy can be used to improve the expression of other antibodies and proteins.

Resistance to Innate Immunity Contributes to Colonization of the Insect Gut by Yersinia pestis.

Yersinia pestis, the causative agent of bubonic and pneumonic plague, is typically a zoonotic vector-borne disease of wild rodents. Bacterial biofilm formation in the proventriculus of the flea contributes to chronic infection of fleas and facilitates efficient disease transmission. However prior to biofilm formation, ingested bacteria must survive within the flea midgut, and yet little is known about vector-pathogen interactions that are required for flea gut colonization. Here we establish a Drosophila melanogaster model system to gain insight into Y. pestis colonization of the insect vector. We show that Y. pestis establishes a stable infection in the anterior midgut of fly larvae, and we used this model system to study the roles of genes involved in biofilm production and/or resistance to gut immunity stressors. We find that PhoP and GmhA both contribute to colonization and resistance to antimicrobial peptides in flies, and furthermore, the data suggest biofilm formation may afford protection against antimicrobial peptides. Production of reactive oxygen species in the fly gut, as in fleas, also serves to limit bacterial infection, and OxyR mediates Y. pestis survival in both insect models. Overall, our data establish the fruit fly as an informative model to elucidate the relationship between Y. pestis and its flea vector.

Dietary, lifestyle and clinicopathological factors associated with APC mutations and promoter methylation in colorectal cancers from the EPIC-Norfolk study.

The tumour suppressor APC is the most commonly altered gene in colorectal cancer (CRC). Genetic and epigenetic alterations of APC may therefore be associated with dietary and lifestyle risk factors for CRC. Analysis of APC mutations in the extended mutation cluster region (codons 1276-1556) and APC promoter 1A methylation was performed on 185 archival CRC samples collected from participants of the European Prospective Investigation into Cancer (EPIC)-Norfolk study, with the aim of relating these to high-quality seven-day dietary and lifestyle data collected prospectively. Truncating APC mutations (APC(+) ) and promoter 1A methylation (PM(+) ) were identified in 43% and 23% of CRCs analysed, respectively. Distal CRCs were more likely than proximal CRCs to be APC(+) or PM(+) (p = 0.04). APC(+) CRCs were more likely to be moderately/well differentiated and microsatellite stable than APC(-) CRCs (p = 0.05 and 0.03). APC(+) CRC cases consumed more alcohol than their counterparts (p = 0.01) and PM(+) CRC cases consumed lower levels of folate and fibre (p = 0.01 and 0.004). APC(+) or PM(+) CRC cases consumed higher levels of processed meat and iron from red meat and red meat products (p = 0.007 and 0.006). Specifically, CRC cases harbouring GC-to-AT transition mutations consumed higher levels of processed meat (35 versus 24 g/day, p = 0.04) and iron from red meat and red meat products (0.8 versus 0.6 mg/day, p = 0.05). In a logistic regression model adjusted for age, sex and cigarette-smoking status, each 19 g/day (1SD) increment increase in processed meat consumption was associated with cases with GC-to-AT mutations (OR 1.68, 95% CI 1.03-2.75). In conclusion, APC(+) and PM(+) CRCs may be influenced by diet and GC-to-AT mutations in APC are associated with processed meat consumption, suggesting a mechanistic link with dietary alkylating agents, such as N-nitroso compounds.

Lifestyle factors and p53 mutation patterns in colorectal cancer patients in the EPIC-Norfolk study.

The tumour suppressor p53 is one of the most commonly altered genes in colorectal cancer (CRC) development. Genetic alterations in p53 may therefore be associated with postulated lifestyle risk factors for CRC, such as red meat consumption. In the European Prospective Investigation into Cancer and Nutrition-Norfolk study, we examined whether detailed estimates of dietary and lifestyle factors measured at baseline related to later development of p53 mutations in CRCs. After 10-year follow-up, there were 185 incident CRCs of which 34% had somatic p53 mutations (p53+). We observed significantly higher mean intakes of alcohol, total meat and red meat, in the group with p53 mutations and advanced Dukes' stage disease (daily alcohol intake was 7 and 12 g for p53- and p53+ cases, respectively, P = 0.04; daily total meat intake was 69 and 100 g for p53- and p53+ cases, respectively, P = 0.03 and daily red meat intake was 39 and 75 g for p53- and p53+ cases, respectively, P = 0.01). Each 50 g/day increment in total meat intake was associated with having p53 mutations in cases with advanced Dukes' stages [odds ratio (OR): 3.43, 95% confidence interval (CI): 1.47-7.96]. Similarly, each 50 g/day increment in red meat intake was also significantly associated with having consistent p53 mutations in cases with advanced Dukes' stages (OR: 2.42, 95% CI: 1.18-4.96). These effects of total meat or red meat intake and advanced Dukes' stages were independent of age, sex, body mass index, smoking and alcohol intake. Furthermore, P values for interaction between daily total meat or red meat intake and Dukes' stages were statistically significant in multivariable models (Pinteraction < 0.001). Our results suggest that p53 mutations accelerate progression of CRC to advanced Dukes' stage in association with higher meat especially red meat intakes.

Candidate tumor suppressor LUCA-15/RBM5/H37 modulates expression of apoptosis and cell cycle genes.

RBM5 (RNA-binding motif protein 5/LUCA-15/H37) is encoded at the lung cancer tumor suppressor locus 3p21.3 and itself has several important characteristics of a tumor suppressor, including both potentiation of apoptosis and inhibition of the cell cycle. Here, we report the effects of both upregulation and downregulation of LUCA-15/RBM5 on gene expression monitored using cDNA microarrays. Many of the genes modulated by LUCA-15/RBM5 are involved in the control of apoptosis, the cell cycle, or both. These effects were confirmed for the most significant genes using real-time RT-PCR and/or Western blotting. In particular, LUCA-15/RBM5 increased the expression of Stat5b and BMP5 and decreased the expression of AIB1 (Amplified In Breast Cancer 1), proto-oncogene Pim-1, caspase antagonist BIRC3 (cIAP-2, MIHC), and CDK2 (cyclin-dependent kinase 2). These effects on multiple genes controlling both apoptosis and proliferation are in line with the functional effects of LUCA-15/RBM5 and indicate that it plays a central role in regulating cell fate consistent with its tumor suppressor activity.

The relationship between measures of executive function, motor performance and externalising behaviour in 5- and 6-year-old children.

In his cognitive-energetic model of information processing Sergeant [Sergeant, J. (2000). The cognitive-energetic model: An empirical approach to ADHD. Neuroscience and Biobehavioral Reviews, 24, 7-12] links executive function (EF) to motor behaviour. This link has been supported by evidence from a number of sources including studies of attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD). Little is known developmentally about this association. Given the rapid change in both motor proficiency and EF that takes place in the pre-school years, this appears an important time to look for the emergence of the link between these factors. In this study we tested 5- and 6-year-old children on motor tasks from the movement assessment battery for children and on measures of response inhibition (Stroop and stop-signal task) and examined the relationship between scores on these measures. Additionally, in order to relate this behaviour to everyday function, the Rowe behavioural rating inventory (RBRI), a teachers' behavioural rating of externalising behaviour, was also gathered and this related to EF and motor performance. It was found that motor performance correlated significantly with RBRI scores (better motor performance with lower externalising behaviour) and with Stroop performance. The relationship between motor performance and stop-signal task performance was in the expected direction but failed to reach significance and there was no clear association between performance on the stop-signal task and either Stroop or RBRI scores. The results are discussed in relation to different aspects of response inhibition (inhibition of a pre-potent response, interference control) and how these might relate to motor control.