Mass spectrometry imaging of SOD1 protein-metal complexes in SOD1G93A transgenic mice implicates demetalation with pathology.

Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motor neurons in the central nervous system (CNS). Mutations in the metalloenzyme SOD1 are associated with inherited forms of ALS and cause a toxic gain of function thought to be mediated by dimer destabilization and misfolding. SOD1 binds two Cu and two Zn ions in its homodimeric form. We have applied native ambient mass spectrometry imaging to visualize the spatial distributions of intact metal-bound SOD1G93A complexes in SOD1G93A transgenic mouse spinal cord and brain sections and evaluated them against disease pathology. The molecular specificity of our approach reveals that metal-deficient SOD1G93A species are abundant in CNS structures correlating with ALS pathology whereas fully metalated SOD1G93A species are homogenously distributed. Monomer abundance did not correlate with pathology. We also show that the dimer-destabilizing post-translational modification, glutathionylation, has limited influence on the spatial distribution of SOD1 dimers.

Differential gene expression underpinning the production of distinct sperm morphs in the wax moth Galleria mellonella.

Male Lepidoptera produce two distinct sperm types; each ejaculate contains both eupyrene sperm, which can fertilize the egg, and apyrene sperm, which are not fertilization competent. These sperm have distinct morphologies, unique functions and different proteomes. Their production is highly regulated, however, very few genes with specific roles in the production of one or other morph have been described. We present the first comparative transcriptomics study of precursors of eupyrene and apyrene sperm to identify genes potentially implicated in regulating or enacting the distinct differentiation programmes. Differentially expressed genes included genes with potential roles in transcriptional regulation, cell cycle and sperm morphology. We identified gene duplications generating paralogues with functions restricted to one or other morph. However, phylogenetic analysis also revealed evolutionary flexibility in expression patterns of duplicated genes between different lepidopteran species. An improved understanding of lepidopteran reproduction will be vital in targeting prevalent pests in agriculture, and on the flip side, ensuring the fertility and thus survival of pollinator populations in response to environmental stress.

Revolutionising health and social care: innovative solutions for a brighter tomorrow - a systematic review of the literature.

BACKGROUND: In an era marked by rapid technological advancements, changing demographics, and evolving healthcare needs, the landscape of health services has been undergoing a profound transformation. Innovation has emerged as a central force driving change in the healthcare sector, as stakeholders across the globe strive to enhance the quality, accessibility, and efficiency of healthcare services. OBJECTIVE: Within this dynamic context, this systematic literature review explored the barriers and driving forces behind successful health service innovation. METHODS: A comprehensive systematic literature review was conducted using the Griffith University Library search engine and databases that included PubMed, ProQuest, Web of Science, Scopus, and CINHAL. To achieve the study goal, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the associated PRISMA checklist guided the review and reporting method. RESULTS: Findings from this review identified a need for a universal definition of health innovation that encompasses the unique complexities and challenges within this context. In our comprehensive analysis of healthcare innovation, we have uncovered pivotal findings that underscore the indispensable nature of a well-structured framework. CONCLUSIONS: To succeed in fostering innovation within the health and social care sectors, it is imperative to establish an overarching organisational culture that meticulously addresses the following key components: team challenges; communication and collaboration; governance goals and authentic leadership, environmental engagement; and innovation endurance. Through systematic analysis of existing literature, this review offers a definition of health innovation, covering its conceptual foundations, determinants, and barriers, and provides a framework for creating an innovative culture.

Laser capture microdissection and native mass spectrometry for spatially-resolved analysis of intact protein assemblies in tissue.

Previously, we have shown that native ambient mass spectrometry imaging allows the spatial mapping of folded proteins and their complexes in thin tissue sections. Subsequent top-down native ambient mass spectrometry of adjacent tissue section enables protein identification. The challenges associated with protein identification by this approach are (i) the low abundance of proteins in tissue and associated long data acquisition timescales and (ii) irregular spatial distributions which hamper targeted sampling of the relevant tissue location. Here, we demonstrate that these challenges may be overcome through integration of laser capture microdissection in the workflow. We show identification of intact protein assemblies in rat liver tissue and apply the approach to identification of proteins in the granular layer of rat cerebellum.

Transgenic expression of cif genes from Wolbachia strain wAlbB recapitulates cytoplasmic incompatibility in Aedes aegypti.

The endosymbiotic bacteria Wolbachia can invade insect populations by modifying host reproduction through cytoplasmic incompatibility (CI), an effect that results in embryonic lethality when Wolbachia-carrying males mate with Wolbachia-free females. Here we describe a transgenic system for recreating CI in the major arbovirus vector Aedes aegypti using CI factor (cif) genes from wAlbB, a Wolbachia strain currently being deployed to reduce dengue transmission. CI-like sterility is induced when cifA and cifB are co-expressed in testes; this sterility is rescued by maternal cifA expression, thereby reproducing the pattern of Wolbachia-induced CI. Expression of cifB alone is associated with extensive DNA damage and disrupted spermatogenesis. The strength of rescue by maternal cifA expression is dependent on the comparative levels of cifA/cifB expression in males. These findings are consistent with CifB acting as a toxin and CifA as an antitoxin, with CifA attenuating CifB toxicity in both the male germline and in developing embryos. These findings provide important insights into the interactions between cif genes and their mechanism of activity and provide a foundation for the building of a cif gene-based drive system in Ae. aegypti.

Native Ambient Mass Spectrometry of an Intact Membrane Protein Assembly and Soluble Protein Assemblies Directly from Lens Tissue.

Membrane proteins constitute around two-thirds of therapeutic targets but present a significant challenge for structural analysis due to their low abundance and solubility. Existing methods for structural analysis rely on over-expression and/or purification of the membrane protein, thus removing any links back to actual physiological environment. Here, we demonstrate mass spectrometry analysis of an intact oligomeric membrane protein directly from tissue. Aquaporin-0 exists as a 113 kDa tetramer, with each subunit featuring six transmembrane helices. We report the characterisation of the intact assembly directly from a section of sheep eye lens without sample pre-treatment. Protein identity was confirmed by mass measurement of the tetramer and subunits, together with top-down mass spectrometry, and the spatial distribution was determined by mass spectrometry imaging. Our approach allows simultaneous analysis of soluble protein assemblies in the tissue.

Mass Spectrometry Detection and Imaging of a Non-Covalent Protein-Drug Complex in Tissue from Orally Dosed Rats.

Here, we demonstrate detection by mass spectrometry of an intact protein-drug complex directly from liver tissue from rats that had been orally dosed with the drug. The protein-drug complex comprised fatty acid binding protein 1, FABP1, non-covalently bound to the small molecule therapeutic bezafibrate. Moreover, we demonstrate spatial mapping of the [FABP1+bezafibrate] complex across a thin section of liver by targeted mass spectrometry imaging. This work is the first demonstration of in situ mass spectrometry analysis of a non-covalent protein-drug complex formed in vivo and has implications for early stage drug discovery by providing a route to target-drug characterization directly from the physiological environment.