Papers by Hector Riveros-Rosas
Frontiers in Pharmacology, Oct 14, 2022
Fish & Shellfish Immunology
Biochemical and Biophysical Research Communications, 2020
The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by a family of... more The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by a family of four genes (HCN1-4). All isoforms are expressed in the heart, HCN4 being the most abundant in the sinoatrial node (SAN). HCN channels are responsible for the "funny" current (If) associated with the generation and autonomic control of the diastolic depolarization phase of cardiac action potential. In this work we performed a proteomic analysis of HCN4 transfected in HEK293 cells. Most of the identified proteins in the HCN4 network belonged to mitochondria. The subcellular localization of HCN channels was predicted in plasma membrane, mitochondria and nucleus. Experimentally, HCN2 (full-length, truncated), HCN3 (full-length, truncated) and HCN4 (truncated) were detected in rat heart mitochondria by immunoblotting. If sensitive to ZD7288, was recorded by patch-clamp in mitoplasts from cardiomyocytes. Mitochondrial membrane potential (ΔΨm) assessment in H9c2 cells revealed that ZD7288 induced almost 50% higher hyperpolarization respect to control at 30 min. Furthermore, ZD7288 reduced oxygen consumption attributed to ATP synthesis in H9c2 cells. In conclusion, we identify for the first time functional HCN channels in mammalian cardiac mitochondria and demonstrate their impact on ΔΨm and respiration.
Abstract Lipid molecules have received traditionally very little attention as components of gener... more Abstract Lipid molecules have received traditionally very little attention as components of general metabolism and cellular signaling in eukaryotes. Originally, lipid function was established as cellular/bodily energy storage and structural components of biological ...
The FASEB Journal, Apr 1, 2019
Archives of Biochemistry and Biophysics, Apr 1, 2018
The physiological regulation of hepatic glutathione efflux by catecholamines is poorly understood... more The physiological regulation of hepatic glutathione efflux by catecholamines is poorly understood. The purpose of this work was to review the role of adrenergic receptors (AR) on total glutathione (G T) efflux in rat liver. Two models were used: isolated hepatocytes and perfused livers. In hepatocytes 10µM adrenaline (Adr), but not isoproterenol (Iso) a β-AR agonist, or phenylephrine (Phe) an α 1-AR agonist, (in a Krebs-Henseleit Buffer (KHB) enriched with Ca 2+ and some aminoacids) increased in 13% G T efflux. In livers perfused with KHB, Adr or Iso at 1 µmolar doses (but not Phe) stimulated 11-fold initial velocity of G T release, but only during the first two minutes of perfusion. This immediate response progressively disappeared during the following 15 min of perfusion. A second phase of G T efflux, observed between 2 and 14 min of perfusion, mimics the one reported earlier in isolated hepatocytes. The ED 50 for Adr and Iso activation are in the range of 320 nM and 10 nM, respectively. Iso-mediated G T release requires Ca 2+ to work, and was prevented by H89, glibenclamide, cystic fibrosis transmembrane regulator (CFTR) antibodies, and a direct CFTR inhibitor. This short-lived G T release system is associated to PKA activation and probably operates through CFTR.
Chemico-Biological Interactions, May 1, 2019
Aldehyde dehydrogenases (ALDHs) comprise one of the most ancient protein superfamilies widely dis... more Aldehyde dehydrogenases (ALDHs) comprise one of the most ancient protein superfamilies widely distributed in the three domains of life. Their members have been extensively studied in animals and plants, sorted out in different ALDH protein families and their participation in a broad variety of metabolic pathways has been documented. Paradoxically, no systematic studies comprising ALDHs from bacteria have been performed so far. Among bacteria, the genus Pseudomonas occupies numerous ecological niches, and is one of the most complex bacterial genera with the largest number of known species. For these reasons, we selected Pseudomonas as a paradigm to analyze the diversity of ALDHs in bacteria. With this aim, complete Pseudomonas genome sequences and annotations were retrieved from NCBI´s RefSeq genome database. The 258 Pseudomonas strains belong to 46 different species, along with 23 with no species designation. The genomes of these Pseudomonas contain from 3,315 to 6,825 annotated protein coding genes. A total of 6,510 ALDH sequences were found in the selected Pseudomonas, with a median of 24 ALDHcoding genes per strain (by comparison humans possess only 19 different ALDH loci). Pseudomonas saudiphocaensis possesses the lowest number of aldh genes (9), while Pseudomonas pseudoalcaligenes KF707 NBRC110670 possesses the maximum number of aldh genes (49). The ALDHs found in Pseudomonas can be sorted out into 42 protein families, with a predominance of 14 families, which contained 76% of all ALDHs found. In this regard, it is important to note that many Pseudomonas genomes have multiple aldh genes coding for proteins belonging to the same family. Given that all strains contained member of families ALDH4, ALDH5, ALDH6, ALDH14, ALDH18 and ALDH27, we consider these families to be part of the core Pseudomonas genome.
Nutrients, May 6, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
FEBS Letters, Mar 20, 2020
Reactive oxygen species participate in regulating intracellular signaling pathways. Herein, we in... more Reactive oxygen species participate in regulating intracellular signaling pathways. Herein, we investigated the reported opposite effects of hydrogen peroxide (H2O2) on metabolic signaling mediated by activated α1‐ and β‐adrenoceptors (ARs) in hepatocytes. In isolated rat hepatocytes, stimulation of α1‐AR increases H2O2 production via NADPH oxidase 2 (NOX2) activation. We find that the H2O2 thus produced is essential for α1‐AR‐mediated activation of the classical hepatic glycogenolytic, gluconeogenic, and ureagenic responses. However, H2O2 inhibits β‐AR‐mediated activation of these metabolic responses. We show that H2O2 mediates its effects on α1‐AR and β‐AR by permeating cells through aquaporin 8 (AQP8) channels and promoting Ca2+ mobilization. Thus, our findings reveal a novel NOX2‐H2O2‐AQP8‐Ca2+ signaling cascade acting downstream of α1‐AR in hepatocytes, which, by negatively regulating β‐AR signaling, establishes negative crosstalk between the two pathways.
Antioxidants, Jul 29, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The FASEB Journal, Apr 1, 2009
The FASEB Journal, Apr 1, 2015
Iron-containing alcohol dehydrogenases (Fe-ADH) were initially found only in microorganisms. Thes... more Iron-containing alcohol dehydrogenases (Fe-ADH) were initially found only in microorganisms. These enzymes catalyze different reactions, all of them assorted as dehydrogenases-reductases. Later, a Fe-ADH was discovered in humans and animals. This Fe-ADH has been characterized in rats and humans displaying activity as a hydroxyacid-oxoacid transhydrogenase (HOT), however, its metabolic role is not completely understood. The aim of our study was obtain insights to understand how an ancient iron-containing dehydrogenase/reductase was converted into a HOT in animals. Our study included an exhaustive bioinformatic analysis that comprise structural, phylogenetic and synteny analyses, as well as intracellular location prediction and positive selection analysis. Fe-ADH sequence analysis in animals showed that these enzymes possess three amino acids insertion, probably related to the new HOT function developed by these enzymes, since these insertion are absent in other non-eukaryotic Fe-ADHs. Phylogenetic analysis...
PLOS ONE, Sep 26, 2018
Few land plants can synthesize and accumulate the osmoprotectant glycine betaine (GB) even though... more Few land plants can synthesize and accumulate the osmoprotectant glycine betaine (GB) even though this metabolic trait has major adaptive importance given the prevalence of drought, hypersaline soils or cold. GB is synthesized from choline in two reactions catalyzed by choline monooxygenases (CMOs) and enzymes of the family 10 of aldehyde dehydrogenases (ALDH10s) that gained betaine aldehyde dehydrogenase activity (BADH). Homolog genes encoding CMO and ALDH10 enzymes are present in all known land plant genomes, but since GB-non-accumulators plants lack the BADH-type ALDH10 isozyme, they would be expected to also lack the CMO activity to avoid accumulation of the toxic betaine aldehyde. To explore CMOs substrate specificity, we performed amino acid sequence alignments, phylogenetic analysis, homology modeling and docking simulations. We found that plant CMOs form a monophyletic subfamily within the Rieske/mononuclear non-heme oxygenases family with two clades: CMO1 and CMO2, the latter diverging from CMO1 after gene duplication. CMO1 enzymes are present in all plants; CMO2s only in the Amaranthaceae high-GB-accumulators plants. CMO2s, and particularly their mononuclear non-heme iron domain where the active site is located, evolved at a faster rate than CMO1s, which suggests positive selection. The homology model and docking simulations of the spinach CMO2 enzyme showed at the active site three aromatic residues forming a box with which the trimethylammonium group of choline could interact through cation-π interactions, and a glutamate, which also may interact with the trimethylammonium group through a chargecharge interaction. The aromatic box and the carboxylate have been shown to be critical for choline binding in other proteins. Interestingly, these residues are conserved in CMO2 proteins but not in CMO1 proteins, where two of these aromatic residues are leucine and the glutamate is asparagine. These findings reinforce our proposal that the CMO1s physiological substrate is not choline but a still unknown metabolite.
<p>The evolutionary history was inferred using the Maximum Likelihood method based on the L... more <p>The evolutionary history was inferred using the Maximum Likelihood method based on the Le-Gascuel model [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166851#pone.0166851.ref001" target="_blank">1</a>]. The tree with the highest log likelihood (-3414819.0869) is shown. Initial tree(s) for the heuristic search was/were obtained automatically applying Neighbor-Join and BioNJ algorithms to a matrix of pairwise distances estimated using a JTT model, and then selecting the topology with superior log likelihood value. A discrete Gamma distribution was used to model evolutionary rate differences among sites (5 categories (+G, parameter = 0.4901)). The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. The analysis involved 1219 amino acid sequences. There were a total of 996 positions in the final dataset.</p
<p>The unrooted phylogenetic tree was inferred using the Maximum Likelihood method based on... more <p>The unrooted phylogenetic tree was inferred using the Maximum Likelihood method based on the Le-Gascuel model [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166851#pone.0166851.ref049" target="_blank">49</a>]. Branches are colored according to the Conserved Domain Database Fe-ADH subfamily they belong. The tree with the highest log likelihood (-2505413,5328) is shown. Similar trees were obtained with maximum-parsimony, minimum-evolution and neighbour-joining methods. A discrete Gamma distribution was used to model evolutionary rate differences among sites (5 categories (+G, parameter = 0.8682)). The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. There were a total of 783 positions in the final dataset. The proportion of replicate trees in which the associated taxa clustered together in a bootstrap test (500 replicates) is given in color next to selected branches. Rectangles and triangles adjacent to each Fe-ADH subfamily name, indicate the presence of protein sequences from archaea domain (triangles), or eukarya domain (rectangles with A (animals), F (fungi), V (viridiplantae), and P (other eukaryotes) in each subfamily. Protein sequences from bacteria are present in all FeADH subfamilies.</p
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Papers by Hector Riveros-Rosas