Peroxisomes and disease - an overview.

Peroxisomes are indispensable for human health and development. They represent ubiquitous subcellular organelles which compartmentalize enzymes responsible for several crucial metabolic processes such as β-oxidation of specific fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species. Peroxisomes are highly flexible organelles that rapidly assemble, multiply and degrade in response to metabolic needs. Basic research on the biogenesis of peroxisomes and their metabolic functions have improved our knowledge about their crucial role in several inherited disorders and in other pathophysiological conditions. The goal of this review is to give a comprehensive overview of the role of peroxisomes in disease. Besides the genetic peroxisomal disorders in humans, the role of peroxisomes in carcinogenesis and in situations related to oxidative stress such as inflammation, ischemia-reperfusion, and diabetes will be addressed.This work was supported by the German Research Foundation (DFG SCHR518/6-1)

The making of a mammalian peroxisome, version 2.0: mitochondria get into the mix

This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.A recent report from the laboratory of Heidi McBride (McGill University) presents a role for mitochondria in the de novo biogenesis of peroxisomes in mammalian cells (1). Peroxisomes are essential organelles responsible for a wide variety of biochemical functions, from the generation of bile, to plasmalogen synthesis, reduction of peroxides, and the oxidation of very long chain fatty acids (2). Like mitochondria, peroxisomes proliferate primarily through growth and division of pre-existing peroxisomes (3-6). However, unlike mitochondria, peroxisomes do not fuse (5,7); further, and perhaps most importantly, they can also be born de novo, a process thought to occur through the generation of pre-peroxisomal vesicles that originate from the endoplasmic reticulum (reviewed in (8,9). De novo peroxisome biogenesis has been extensively studies in yeast, with a major focus on the role of the ER in this process. Comprehensive studies in mammalian cells are, however, scarce (5,10-12). By exploiting patient cells lacking mature peroxisomes, Sugiura et al. (1) now assign a role to ER and mitochondria in de novo mammalian peroxisome biogenesis by showing that the formation of immature preperoxisomes occurs through the fusion of Pex3- / Pex14-containing mitochondriaderived vesicles with Pex16-containing ER-derived vesicles

Putative adjunct therapies to target mitochondrial dysfunction and oxidative stress in phenylketonuria, lysosomal storage disorders and peroxisomal disorders

Introduction: Oxidative stress (OS) and mitochondrial dysfunction are implicated in the pathogenesis of a number of metabolic diseases. OS occurs when there is an imbalance between the pro-oxidant/antioxidant homeostasis, leading to an increased generation of reactive oxidant species (ROS) with resultant cellular dysfunction. It is becoming apparent that increased ROS generation may be attributable to secondary mitochondrial dysfunction as a consequence of disease pathophysiology. Mitochondrial dysfunction occurs as a result of oxidative damage from enhanced ROS generation as well as the accumulation of toxic metabolites in some metabolic diseases. Areas covered: The present review will discuss evidence of OS and mitochondrial dysfunction in phenylketonuria (PKU), lysosomal storage disorders (LSDs), and peroxisomal disorders. In addition, potential adjunct therapies which have the potential to enhance mitochondrial functioning and mitigate OS will be explored. The databases utilized for this review were Pubmed and the Wed of science, with inclusive dates, 1988–2020. Expert opinion: There is an un-unified approach in the treatment of metabolic diseases. Agents including augmenters of mitochondrial function, antioxidants, and activators of mitochondrial biogenesis, may be beneficial. However, although successful in some cases, these adjunct therapies have yet to be incorporated into the clinical-management of metabolic diseases

A role for Mitochondrial Rho GTPase 1 (MIRO1) in motility and membrane dynamics of peroxisomes

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordPeroxisomes are dynamic organelles which fulfil essential roles in lipid and ROS metabolism. Peroxisome movement and positioning allows interaction with other organelles and is crucial for their cellular function. In mammalian cells, such movement is microtubule-dependent and mediated by kinesin and dynein motors. The mechanisms of motor recruitment to peroxisomes are largely unknown, as well as the role this plays in peroxisome membrane dynamics and proliferation. Here, using a combination of microscopy, live-cell imaging analysis and mathematical modelling, we identify a role for the Ras GTPase MIRO1 as an adaptor for microtubule-dependent peroxisome motility in mammalian cells. We show that MIRO1 is targeted to peroxisomes and alters their distribution and motility. Using a peroxisome-targeted MIRO1 fusion protein, we demonstrate that MIRO1-mediated pulling forces contribute to peroxisome membrane elongation and proliferation in cellular models of peroxisome disease. Our findings reveal a molecular mechanism for establishing peroxisome-motor protein associations in mammalian cells and provide new insights into peroxisome membrane dynamics in health and disease.We thank all colleagues who provided cell lines, plasmids and antibodies (see Tables S1-S4). This work was supported by BBSRC (BB/K006231/1, BB/N01541X/1) and FCT (PTDC/BIA-BCM/118605/2010) to MS; DMR, MS and JM were supported by a Wellcome Trust Institutional Strategic Support Award (WT105618MA; WT097835MF) and DMR by the Medical Research Council (MR/P022405/1). DR and AG were supported by personal fellowship grants from the Portuguese Foundation for Science and Technology (FCT) (SFRH/BPD/77619/2011; SFRH/BD/81223/2011) under the scope of “Programa Operacional Temático Factores de Competitividade” (COMPETE) of “Quadro Comunitário de Apoio III” and co-financed by Fundo Comunitário Europeu (FEDER). The authors declare no conflict of interest