State of the art: gene therapy of haemophilia.

Clinical gene therapy has been practiced for more than a quarter century and the first products are finally gaining regulatory/marketing approval. As of 2016, there have been 11 haemophilia gene therapy clinical trials of which six are currently open. Each of the ongoing phase 1/2 trials is testing a variation of a liver-directed adeno-associated viral (AAV) vector encoding either factor VIII (FVIII) or factor IX (FIX) . As summarized herein, the clinical results to date have been mixed with some perceived success and a clear recognition of the immune response to AAV as an obstacle to therapeutic success. We also attempt to highlight promising late-stage preclinical activities for AAV-FVIII where, due to inherent challenges with manufacture, delivery and transgene product biosynthesis, more technological development has been necessary to achieve results comparable to what has been observed previously for AAV-FIX. Finally, we describe the development of a stem cell-based lentiviral vector gene therapy product that has the potential to provide lifelong production of FVIII and provide a functional 'cure' for haemophilia A. Integral to this program has been the incorporation of a blood cell-specific gene expression element driving the production of a bioengineered FVIII designed for optimal efficiency. As clearly outlined herein, haemophilia remains at the forefront of the rapidly advancing clinical gene therapy field where there exists a shared expectation that transformational advances are on the horizon.

Deconditioning.

Many authors have stressed the negative effects of prolonged immobility by emphasizing organ system changes. When treating individuals for various medical problems, equal regard should be given to functional decline as well. Beneficial exercise programs can be adapted for geriatric populations regardless of their disability. As the geriatric population increases, competition for health care resources increases as well. Emphasis should be placed on community-based programs that value prevention, restoration, and maintenance as worthwhile endeavors. Exercise should be the foundation for these programs and the goal should be to maximize functional skills. The benefits of exercise (Table 4) are physiologic, psychologic, and sociologic and greatly affect the perceived quality of life (Table 5). The adage "use it or lose it" should be heeded by all age levels. As we get older, it becomes more difficult to maintain physical conditioning, which can be discouraging to some and challenging to others. However, the importance of maintaining fitness with our advancing years is becoming increasingly clear. Bortz has stated that disuse syndromes affect far too many people in their later years. He challenges older people to live active lives to the end and ideally compress morbidity into a final short period of life.

Structure and function of Parkin E3 ubiquitin ligase reveals aspects of RING and HECT ligases.

Parkin is a RING-between-RING E3 ligase that functions in the covalent attachment of ubiquitin to specific substrates, and mutations in Parkin are linked to Parkinson's disease, cancer and mycobacterial infection. The RING-between-RING family of E3 ligases are suggested to function with a canonical RING domain and a catalytic cysteine residue usually restricted to HECT E3 ligases, thus termed 'RING/HECT hybrid' enzymes. Here we present the 1.58 Å structure of Parkin-R0RBR, revealing the fold architecture for the four RING domains, and several unpredicted interfaces. Examination of the Parkin active site suggests a catalytic network consisting of C431 and H433. In cells, mutation of C431 eliminates Parkin-catalysed degradation of mitochondria, and capture of an ubiquitin oxyester confirms C431 as Parkin's cellular active site. Our data confirm that Parkin is a RING/HECT hybrid, and provide the first crystal structure of an RING-between-RING E3 ligase at atomic resolution, providing insight into this disease-related protein.