Dementia and COVID-19 in New Zealand, Chile, and Germany: A Research Agenda for Cross-Country Learning for Resilience in Health Care Systems

The COVID-19 pandemic has revealed existing gaps in policies, systems and services, stressing the need for concerted global action on healthy aging. Similar to the COVID-19 pandemic, dementia is a challenge for health systems on a global scale. Our hypothesis is that translational potential lies in cross-country learning by involving three high-income countries with distinct geo political-cultural-social systems in Latin America (Chile), the South Pacific (New Zealand) and Eu rope (Germany). Our vision is that such cross-country learning will lead to providing adequate, equitable and sustainable care and support for families living with dementia during a pandemic and beyond. We are proposing a vision for research that takes a multi-disciplinary, strength-based approach at the intersection of health care research, disaster research, global health research and dementia research. We present some insights in support of our hypothesis and proposed research agenda. We anticipate that this research has the potential to contribute towards strengthening and transforming health care systems in times of crises and beyond

Human native lipoprotein-induced de novo DNA methylation is associated with repression of inflammatory genes in THP-1 macrophages

<p>Abstract</p> <p>Background</p> <p>We previously showed that a VLDL- and LDL-rich mix of human native lipoproteins induces a set of repressive epigenetic marks, <it>i.e. de novo </it>DNA methylation, histone 4 hypoacetylation and histone 4 lysine 20 (H4K20) hypermethylation in THP-1 macrophages. Here, we: 1) ask what gene expression changes accompany these epigenetic responses; 2) test the involvement of candidate factors mediating the latter. We exploited genome expression arrays to identify target genes for lipoprotein-induced silencing, in addition to RNAi and expression studies to test the involvement of candidate mediating factors. The study was conducted in human THP-1 macrophages.</p> <p>Results</p> <p>Native lipoprotein-induced <it>de novo </it>DNA methylation was associated with a general repression of various critical genes for macrophage function, including pro-inflammatory genes. Lipoproteins showed differential effects on epigenetic marks, as <it>de novo </it>DNA methylation was induced by VLDL and to a lesser extent by LDL, but not by HDL, and VLDL induced H4K20 hypermethylation, while HDL caused H4 deacetylation. The analysis of candidate factors mediating VLDL-induced DNA hypermethylation revealed that this response was: 1) surprisingly, mediated exclusively by the canonical maintenance DNA methyltransferase DNMT1, and 2) independent of the Dicer/micro-RNA pathway.</p> <p>Conclusions</p> <p>Our work provides novel insights into epigenetic gene regulation by native lipoproteins. Furthermore, we provide an example of DNMT1 acting as a <it>de novo </it>DNA methyltransferase independently of canonical <it>de novo </it>enzymes, and show proof of principle that <it>de novo </it>DNA methylation can occur independently of a functional Dicer/micro-RNA pathway in mammals.</p