Rab7a and Mitophagosome Formation.

The small GTPase, Rab7a, and the regulators of its GDP/GTP-binding status were shown to have roles in both endocytic membrane traffic and autophagy. Classically known to regulate endosomal retrograde transport and late endosome-lysosome fusion, earlier work has indicated a role for Rab7a in autophagosome-lysosome fusion as well as autolysosome maturation. However, as suggested by recent findings on PTEN-induced kinase 1 (PINK1)-Parkin-mediated mitophagy, Rab7a and its regulators are critical for the correct targeting of Atg9a-bearing vesicles to effect autophagosome formation around damaged mitochondria. This mitophagosome formation role for Rab7a is dependent on an intact Rab cycling process mediated by the Rab7a-specific guanine nucleotide exchange factor (GEF) and GTPase activating proteins (GAPs). Rab7a activity in this regard is also dependent on the retromer complex, as well as phosphorylation by the TRAF family-associated NF-κB activator binding kinase 1 (TBK1). Here, we discuss these recent findings and broadened perspectives on the role of the Rab7a network in PINK1-Parkin mediated mitophagy.

Intervention for Cardiac Repair: A Clinical Perspective.

Cardiovascular disease remains the leading cause of death worldwide. Damage to the heart resulting from cardiovascular disease leads to gradual loss of function and reduced quality of life. Cardiac injury is particularly debilitating, more so than injury to any other organ, given our current inability to either generate new and functional cardiac tissue or to mimic the actions of the heart using external devices. Advances in the field of stem cells and genetics have paved the way for the development of a variety of novel therapies. A number of these therapies have shown great promise in regenerating cardiac tissue in non-human disease models and some have progressed towards clinical trials. Given the rapid progress and emergence of novel targets for therapy, it is perhaps timely that we assess the practicality of these techniques and their potential for translation to bedside. Hence, this review aims to outline the major therapies in development and to provide insight into the feasibility of the respective techniques with the hope that research can be steered towards developing therapies with greater potential of being employed at the bedside.