Ghrelin mediated cardioprotection using in vitro models of oxidative stress

Ghrelin is commonly known as the 'hunger hormone' due to its role in stimulating food intake in humans. However, the roles of ghrelin extend beyond regulating hunger. Our aim was to investigate the ability of ghrelin to protect against hydrogen peroxide (H2O2), a reactive oxygen species commonly associated with cardiac injury. An in vitro model of oxidative stress was developed using H2O2 injured H9c2 cells. Despite lentiviral ghrelin overexpression, H9c2 cell viability and mitochondrial function were not protected following H2O2 injury. We found that H9c2 cells lack expression of the preproghrelin cleavage enzyme prohormone convertase 1 (encoded by PCSK1), required to convert ghrelin to its active form. In contrast, we found that primary rat cardiomyocytes do express PCSK1 and were protected from H2O2 injury by lentiviral ghrelin overexpression. In conclusion, we have shown that ghrelin expression can protect primary rat cardiomyocytes against H2O2, though this effect was not observed in other cell types tested.

Improving the accuracy of blood pressure measuring devices in Australia: a modelled return on investment study

The VALID BP project was initiated to increase the availability of validated blood pressure measuring devices (BPMDs). The goal is to eliminate non validated BPMDs and minimise over- and underdiagnosis of hypertension caused by inaccurate readings. This study was undertaken to assess the potential return on investment in the VALID BP project. The Framework to Assess the Impact of Translational Health Research was applied to the VALID BP project. This paper focuses on the implementation of the cost benefit analysis aspect of this framework to monetise past research investment and model future research costs, implementation costs, and benefits. Analysis was based on reasoned assumptions about potential impacts from availability and use of validated BPMDs (assuming an end goal of 100% validated BPMDs available in Australia by 2028) and improved skills leading to more accurate BP measurement. After 5 years, with 20% attribution of benefits, there is a potential $1.14-$1.30 return for every dollar spent if the proportion of validated BPMDs and staff trained in proper BP measurement technique increased from 20% to 60%. After eight years (2020-2028) and assuming universal validation and training coverage, the returns would be between $2.70 and $3.20 per dollar spent (not including cost of side effects of unnecessary medication or downstream patient impacts from unmanaged hypertension). This modelled economic analysis indicates there will be positive downstream economic benefits if the availability of validated BPMDs is increased. The findings support ongoing efforts toward a universal regulatory framework for BPMDs and can be considered within more detailed future economic analyses.

"I am not a number!" Opinions and preferences of people with intellectual disability about genetic healthcare

There is limited research exploring the knowledge and experiences of genetic healthcare from the perspective of people with intellectual disability. This study, conducted in New South Wales (Australia), addresses this gap. Eighteen adults with intellectual disability and eight support people were interviewed in this inclusive research study. The transcribed interviews were analysed using inductive content analysis. The findings were discussed in a focus group with ten adults with intellectual disability and in three multi-stakeholder advisory workshops, contributing to the validity and trustworthiness of the findings. Five main themes emerged: (i) access to genetic healthcare services is inequitable, with several barriers to the informed consent process; (ii) the experiences and opinions of people with intellectual disability are variable, including frustration, exclusion and fear; (iii) genetic counselling and diagnoses can be profoundly impactful, but translating a genetic diagnosis into tailored healthcare, appropriate support, peer connections and reproductive planning faces barriers; (iv) people with intellectual disability have a high incidence of exposure to trauma and some reported that their genetic healthcare experiences were associated with further trauma; (v) recommendations for a more respectful and inclusive model of genetic healthcare. Co-designed point-of-care educational and consent resources, accompanied by tailored professional education for healthcare providers, are required to improve the equity and appropriateness of genetic healthcare for people with intellectual disability.

Hydrogen peroxide signaling via its transformation to a stereospecific alkyl hydroperoxide that escapes reductive inactivation

During systemic inflammation, indoleamine 2,3-dioxygenase 1 (IDO1) becomes expressed in endothelial cells where it uses hydrogen peroxide (H₂O₂) to oxidize L-tryptophan to the tricyclic hydroperoxide, cis-WOOH, that then relaxes arteries via oxidation of protein kinase G 1α. Here we show that arterial glutathione peroxidases and peroxiredoxins that rapidly eliminate H₂O₂, have little impact on relaxation of IDO1-expressing arteries, and that purified IDO1 forms cis-WOOH in the presence of peroxiredoxin 2. cis-WOOH oxidizes protein thiols in a selective and stereospecific manner. Compared with its epimer trans-WOOH and H₂O₂, cis-WOOH reacts slower with the major arterial forms of glutathione peroxidases and peroxiredoxins while it reacts more readily with its target, protein kinase G 1α. Our results indicate a paradigm of redox signaling by H₂O₂ via its enzymatic conversion to an amino acid-derived hydroperoxide that 'escapes' effective reductive inactivation to engage in selective oxidative activation of key target proteins.