Our dementia challenge: arise palliative care.

While many of the maladies of the 20th century are steadily coming under control, the march of neurodegenerative disorders continues largely unchecked. Dementias are an exemplar of such disorders; their incidence and prevalence continue to rise, in large part due to a steadily ageing population worldwide. They represent a group of chronic, progressive and, ultimately, fatal neurodegenerative diseases. Dementia has remained therapeutically recalcitrant. It is not a single disease, and because of that, we cannot expect a single panacea. While primary prevention rightly gains prominence, those with established disease currently require a shift in focus from curative intent towards improved quality of life. Enter palliative care. The sheer number and complexity of needs of patients with dementia, from the physical to the psychosocial and spiritual, necessitates the engagement of a wide range of medical disciplines, nursing and allied health professionals. One of those disciplines, as highlighted in the recent Australian Royal Commission into Aged Care Quality and Safety, is palliative care. This paper shall expand upon that role in the overall context of care for those with dementia.

Mitotic raptor promotes mTORC1 activity, G(2)/M cell cycle progression, and internal ribosome entry site-mediated mRNA translation.

The mTOR signaling complex integrates signals from growth factors and nutrient availability to control cell growth and proliferation, in part through effects on the protein-synthetic machinery. Protein synthesis rates fluctuate throughout the cell cycle but diminish significantly during the G(2)/M transition. The fate of the mTOR complex and its role in coordinating cell growth and proliferation signals with protein synthesis during mitosis remain unknown. Here we demonstrate that the mTOR complex 1 (mTORC1) pathway, which stimulates protein synthesis, is actually hyperactive during mitosis despite decreased protein synthesis and reduced activity of mTORC1 upstream activators. We describe previously unknown G(2)/M-specific phosphorylation of a component of mTORC1, the protein raptor, and demonstrate that mitotic raptor phosphorylation alters mTORC1 function during mitosis. Phosphopeptide mapping and mutational analysis demonstrate that mitotic phosphorylation of raptor facilitates cell cycle transit through G(2)/M. Phosphorylation-deficient mutants of raptor cause cells to delay in G(2)/M, whereas depletion of raptor causes cells to accumulate in G(1). We identify cyclin-dependent kinase 1 (cdk1 [cdc2]) and glycogen synthase kinase 3 (GSK3) pathways as two probable mitosis-regulated protein kinase pathways involved in mitosis-specific raptor phosphorylation and altered mTORC1 activity. In addition, mitotic raptor promotes translation by internal ribosome entry sites (IRES) on mRNA during mitosis and is demonstrated to be associated with rapamycin resistance. These data suggest that this pathway may play a role in increased IRES-dependent mRNA translation during mitosis and in rapamycin insensitivity.

Transforming growth factor-beta and microRNA:mRNA regulatory networks in epithelial plasticity.

Noncoding microRNAs act as posttranscriptional repressors of gene function and are often deregulated in cancers and other diseases. Here we review recent findings on microRNA roles in tumorigenesis and report a microRNA profiling screen in transforming growth factor-beta1 (TGF-beta)-induced epithelial-mesenchymal transition (EMT) in human keratinocytes, a model of epithelial cell plasticity underlying epidermal injury and skin carcinogenesis. We describe a novel EMT-specific microRNA signature that includes induction of miR-21, a candidate oncogenic microRNA associated with carcinogenesis. By integrating the microRNA screen results with target prediction algorithms and gene expression profiling data, we outline a framework for TGF-beta-directed microRNA:messenger RNA (mRNA) regulatory circuitry and discuss its biological relevance for tumor progression.