Protein disulfide isomerase regulates blood vessel caliber in vascular disease

Redoxoma Highlights | F. LaurindoPDI regulates blood vessel caliber in vascular disease

While the intuitive idea is that the lumen of diseased blood vessels narrows due to the pathological growth of a migrating cell mass, similar to rust in an old pipe, actually the lumen of diseased vessels is strongly influenced by a phenomenon called vascular remodeling, the structural reorganization of whole-vessel circumference. Typically, remodeling is the sole determinant of vessel lumen due to blood flow changes, in which redox signaling processes play an important mediator role in association with NO biovailability. However, redox processes appear to mediate other forms of vascular remodeling as well, such as those associated with atherosclerosis-related processes. We showed previously


Is redox metabolism connected with Circadian Rhythm?

Highlights | Carolina G. FernandesIs redox metabolism connected with Circadian Rhythm?

by Carolina Gonçalves Fernandes

Circadian Rhythm is any biological process that temporally organizes behavioral, physiological, and molecular events around the 24h day-night cycle. This process has evolved over approximately 2.5 billion years ago at the Great Oxidation Event. The later involved increases in atmospheric oxygen levels that simulatenwously enabled organisms to resonate with their environment such that their internal cycles anticipate and match external rhythms on Earth. In mammals, this rhythmicity is controlled by the hypothalamic suprachiasmatic nuclei (SCN) receiving retina signals and “translating” them into each tissue/organ that commonly responds using the transcription/translation


Mitochondria and lysosomes: lords of life and death in cells?

by Mauricio da Silva Baptista

An important aim of our CEPID-Redoxoma is to develop diagnostic and therapeutic applications of redox processes. In this context, antioxidant therapies are at the frontline of our interests as a group. In parallel, however, a smaller but nonetheless significant group of strategies aim to explore prooxidant and stress-enhancing effects of distinct interventions, mainly to achieve selective toxicity towards damaged or tumor cells. The group of Prof. Mauricio S. Baptisata, from our CEPID-Redoxoma, has been exploring for more than a decade photo-induced compounds as a means to achieve such type of effects. Interestingly, this group recently provided a significant contribution


How I see the future of redox research

Henry Jay Forman

by Henry Jay Forman

With this issue, we start a series of short texts about the theme “How I see the future of redox research”. The radical-free corner was really radical in this regard and invited several prominent colleagues from Brazil and abroad. These comments are meant to be highly personal accounts, by known experts, of the directions they foresee redox research. We are sure these short insertions will kick on our minds to help our thinking.

And we started in great style, with no one less than Prof. Henry Jay Forman, a long-standing investigator of the area. Prof. Forman is the Distinguished Professor of Chemistry and Biochemistry, University of California, Merced, and the former


Mitochondria can dictate your fate, especially if you’re a stem cell

Redoxoma Highlights | Mitochondria can dictate your fate, especially if you’re a stem cell  Maria F. Forni

by Maria F. Forni*

Known for over a century, mitochondria have become, during the last four decades, an important subject of research within several disciplines. This is mostly due to the fact that this organelle comprises the site of oxidative phosphorylation, the citric acid cycle, fatty acid oxidation, the urea cycle and the biosynthesis of iron-sulphur centres and haem. Moreover, mitochondria are an important redox-signaling node. Indeed, the bioenergetic status of a cell is dependent on the overall quality and relative abundance of the mitochondrial population it harbors. Recent evidence suggests that the control of mitochondrial mass and morphology occurs through the processes of fusion


The hard path towards accurately measuring in vivo enzyme activity: the case of protein disulfide isomerase

by Denise C. Fernandes

Correct protein folding is a vital and extremely regulated cellular function. Disulfide bonds are essential determinants of the correctly folded protein structure. During the folding of nascent proteins into the endoplasmic reticulum (ER) lumen, essential enzymes promote disulfide bond insertion (oxidation) and their eventual repositioning (isomerization) when they are initially formed between wrong cysteines. These reactions are catalyzed by PDIs (protein disulfide isomerases), a family of enzymes that contains more than 20 members, from yeast to humans [1]. Thus, PDIs do not have one specific substrate, but rather a large variety of un/misfolded protein substrates.



Mitochondria-to-nucleus communication controls mitochondrial activity and stress resistance in yeast

Redoxoma Highlights | Mitochondria-to-nucleus communication controls mitochondrial activity and stress resistance in yeast by Fernanda M. Cunha

by Fernanda M. Cunha

Mitochondria are believed to be former free living bacteria that established a successful symbiotic relationship with eukaryotic cells in such a way that today, besides being crucial for the biosynthesis of intermediary metabolites, calcium homeostasis, coordination of apoptosis and ATP synthesis, most mitochondrial proteins are encoded by nuclear rather than mitochondrial DNA. In that scenario, communication pathways that relay signals from the nucleus to mitochondria as well as from mitochondria to the nucleus (the retrograde way) are mandatory to secure energetic and metabolic homeostasis. In yeast, the best characterized retrograde signaling pathway, activated whenever


Yes, together we can…. A highly conserved histidine residue in 2-Cys peroxiredoxins acts as a pH sensor for oligomerization

by Luis E. S. Netto

Peroxiredoxin (Prx) enzymes are becoming more and more popular among other reasons due to their high reactivity towards hydroperoxides and to their abundance. As a consequence, Prxs are proposed as biological sensors of hydrogen peroxide. It is interesting to observe that since their beginnings (in the end of the 60’s), one feature that called attention was their ability to form high molecular weight species, visible by electron microscopy [1]. It was almost twenty years later that the thiol-dependent peroxidase activity of Prx enzymes was described.

Among Prx family of proteins, 2-Cys Prx enzymes (those belonging to the AhpC/Prx1 group) can adopt a wide array of quartenary


Free radicals: should clinicians pay attention to them?

by Protasio L. da Luz*

Within the Cepid-Redoxoma, we are deeply involved in redox research and we consider this very important, of course. However, it is interesting at times to see how some meaningful outsiders interpret the area. The Radical-Free Corner challenged a highly experienced academic clinician-scientist, who kindly accepted this task (he happens to have been the Editor’s doctorate supervisor – a minor conflict of interest, I confess)

(Editor’s comment)

Oxidative stress pervades several areas of Medicine: aging, cancer, atherosclerosis and other degenerative conditions, principally. Several studies claim that it is the cause of aging. But while there is evidence for


A comprehensive approach to identify redox and non-redox targets of Trx-like proteins

by Lia S. Nakao

Like the old dictum that says “birds of a feather flock together”, understanding the specific partners of a given protein provides an important clue about its function. Thioredoxin 1 (Trx1) is a well-known redox protein that contains a CXXC motif (cysteines residues flanking two aminoacid residues), responsible for its disulfide reductase function. The first (C-terminal) Cys of the motif attacks the disulfide of the target protein, producing a short lived mixed disulfide, which is reduced by the second (N-terminal resolving) Cys, releasing Trx1 and the target, in the oxidized and reduced forms, respectively. If the resolving Cys is replaced by a non-redox residue, such as