A Survey of Community Perceptions on Brain Donation for Research.

Postmortem brain donation for medical research is a little-known form of organ donation. While most brain research is carried out using animal models, many neurological diseases are uniquely human. Greater availability of human postmortem brain tissue from diseased individuals and controls would therefore improve the development of treatments for neurological and neuropsychiatric diseases. Globally, organ donation for medical research is dwarfed by organ donation for transplantation. In 2021, 36% of Australians were registered organ donors for transplantation, with public "in-principle" support even higher, at 76%. In contrast, there are little data on Australian or international brain donation rates for research. A 30-item online survey was conducted to ascertain knowledge of, and attitudes toward, brain donation in Australia. Of the respondents, 12/237 (5%) were current brain donors and excluded from further analysis. Of the remaining 225, 75% were registered organ donors for transplant. The vast majority (n = 189/225, 84%) of respondents supported or strongly supported the principle of brain donation. However, of those registered for transplantation or whole-body donors, 93/170 (55%) were not aware that brain donation was possible, while 50%, alternatively or also, thought that registering as an organ donor for transplantation rendered them a brain donor by default. Only 9/225 (4%) respondents indicated that they would definitely not donate their brain in the future, while 27 remained unsure. There is prominent public support for brain donation in Australia, with 84% of respondents willing to donate their brain. Yet, the extent of public misconceptions on brain donation for research suggests the need for further education on all types of organ donation, so individuals may make informed decisions.

Double Chromogen-based Immunohistochemical Staining: An Efficient Approach for Utilizing Long-term Formalin-fixed Tissue in Biobanks.

The New South Wales Brain Tissue Resource Centre is a human brain bank that provides top-quality brain tissue for cutting-edge neuroscience research spanning various conditions from alcohol use disorder to neurodegenerative diseases. However, the conventional practice of preserving brain tissue in formalin poses challenges for immunofluorescent staining primarily due to the formalin's tendency, over time, to create cross-links between antigens, which can obscure epitopes of interest. In addition, researchers can encounter issues such as spectral bleeding, limitations in using multiple colors, autofluorescence, and cross-reactivity when working with long-term formalin-fixed brain tissue. The purpose of the study was to test chromogen-based double immunolabeling to negate the issues with immunofluorescent staining. Colocalization of antigens was explored using chromogens 3-amino-9-ethylcarbazole (AEC) and 3,3,-diaminobenzidine in a sequential staining procedure where the AEC signal was eliminated by alcohol treatment. Combinations of 2 or 3 primary antibodies from the same or different species were trialed successfully with this protocol. The colocalization of antigens was also demonstrated with pseudocoloring that mimicked immunofluorescence staining. This staining technique increases the utility of archival formalin-fixed tissue samples.

Phosphatidylethanol in post-mortem brain: Correlation with blood alcohol concentration and alcohol use disorder.

Phosphatidylethanol (PEth) is an alcohol derivative that has been employed as a blood-based biomarker for regular alcohol use. This study investigates the utility of phosphatidylethanol (PEth) as a biomarker for assessing alcohol consumption in post-mortem brain tissue. Using samples from the New South Wales Brain Tissue Resource Centre, we analysed PEth(16:0/18:1) levels in the cerebellum and meninges of individuals with varying histories of alcohol use, including those diagnosed with alcohol use disorder (AUD) and controls. Our findings demonstrate a significant correlation between PEth levels and blood alcohol content (BAC) at the time of death, supporting the biomarker's sensitivity to recent alcohol intake. Furthermore, this study explores the potential of PEth levels in differentiating AUD cases from controls, taking into consideration the complexities of diagnosing AUD post-mortem. The study also examined the relationship between PEth levels and liver pathology, identifying a link with the severity of liver damage. These results underscore the value of PEth as a reliable indicator of alcohol consumption and its potential contributions to post-mortem diagnostics and consequently, research into alcohol-related brain damage.

Metastasis-Free Survival Versus Treatment-Free Survival in Biochemically Recurrent Prostate Cancer: The EMBARK Trial.

What is most important to patients with BCR prostate cancer? Metastasis-free versus treatment-free survival.

Loss of neuronal lysosomal acid lipase drives amyloid pathology in Alzheimer's disease.

Underlying drivers of late-onset Alzheimer's disease (LOAD) pathology remain unknown. However, multiple biologically diverse risk factors share a common pathological progression. To identify convergent molecular abnormalities that drive LOAD pathogenesis we compared two common midlife risk factors for LOAD, heavy alcohol use and obesity. This revealed that disrupted lipophagy is an underlying cause of LOAD pathogenesis. Both exposures reduced lysosomal flux, with a loss of neuronal lysosomal acid lipase (LAL). This resulted in neuronal lysosomal lipid (NLL) accumulation, which opposed Aß localization to lysosomes. Neuronal LAL loss both preceded (with aging) and promoted (targeted knockdown) Aß pathology and cognitive deficits in AD mice. The addition of recombinant LAL ex vivo and neuronal LAL overexpression in vivo prevented amyloid increases and improved cognition. In WT mice, neuronal LAL declined with aging and correlated negatively with entorhinal Aß. In healthy human brain, LAL also declined with age, suggesting this contributes to the age-related vulnerability for AD. In human LOAD LAL was further reduced, correlated negatively with Aß1-42, and occurred with polymerase pausing at the LAL gene. Together, this finds that the loss of neuronal LAL promotes NLL accumulation to impede degradation of Aß in neuronal lysosomes to drive AD amyloid pathology.

Integrated Single-Cell Multiomic Profiling of Caudate Nucleus Suggests Key Mechanisms in Alcohol Use Disorder.

Alcohol use disorder (AUD) is likely associated with complex transcriptional alterations in addiction-relevant brain regions. We characterize AUD-associated differences in cell type-specific gene expression and chromatin accessibility in the caudate nucleus by conducting a single-nucleus RNA-seq assay and a single-nucleus RNA-seq + ATAC-seq (multiome) assay on caudate tissue from 143 human postmortem brains (74 with AUD). We identified 17 cell types. AUD was associated with a higher proportion of microglia in an activated state and more astrocytes in a reactive state. There was widespread evidence for differentially expressed genes across cell types with the most identified in oligodendrocytes and astrocytes, including genes involved in immune response and synaptic regulation, many of which appeared to be regulated in part by JUND and OLIG2 . Microglia-astrocyte communication via interleukin-1 beta, and microglia-astrocyte-oligodendrocyte interaction via transforming growth factor beta 1 were increased in individuals with AUD. Expression quantitative trait loci analysis revealed potential driver genes of AUD, including ADAL, that may protect against AUD in medium spiny neurons and interneurons. This work provides a thorough profile of the effects of AUD in the human brain and identifies several promising genes for further study.