RESUMO
The immune system of sturgeons, one of the most ancient and economically valuable fish worldwide, is poorly understood. The lack of molecular tools and data about infection biomarkers hinders the possibility to monitor sturgeon health during farming and detect infection outbreaks. To tackle this issue, we mined publicly available transcriptomic datasets and identified putative positive acute-phase proteins (APPs) of Russian sturgeons that could be induced by a bacterial infection and monitored using non-invasive methods. Teleost literature compelled us to focus on five promising candidates: hepcidin, a warm acclimation associated hemopexin, intelectin, serum amyloid A protein (SAA) and serotransferrin. Among them, SAA was the most upregulated protein at the mRNA level in the liver of sturgeons challenged with heat-inactivated or live Aeromonas hydrophila. To assess whether this upregulation yielded increasing SAA levels in circulation, we developed an in-house ELISA to quantify SAA levels in sturgeon serum. Circulating SAA rose upon bacterial challenge and positively correlated with hepatic saa expression. This is the first time serum SAA has been quantified in an Actinopterygii fish. Since APPs vary across different fish species, our work sheds light on sturgeon acute-phase response, revealing that SAA is a positive APP with potential value as infection biomarker.
Assuntos
Proteínas de Fase Aguda/genética , Aeromonas hydrophila , Peixes/genética , Peixes/microbiologia , Interações Hospedeiro-Patógeno/genética , Proteína Amiloide A Sérica/genética , Proteínas de Fase Aguda/química , Reação de Fase Aguda , Sequência de Aminoácidos , Animais , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Doenças dos Peixes/genética , Doenças dos Peixes/microbiologia , Peixes/imunologia , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Modelos Moleculares , Conformação Proteica , Proteína Amiloide A Sérica/química , Relação Estrutura-Atividade , TranscriptomaRESUMO
Peroxisome proliferator-activated receptors (PPARs) are multi-domains proteins, belonging to the superfamily of nuclear receptors, which mainly act as ligand-activated transcription factors. A variety of lipophilic molecules, including long-chain polyunsaturated fatty acids and eicosanoids, are capable of binding to PPAR, although the nature of the physiological ligands is still under debate. PPARs regulate the expression of a set of genes involved in glucose and lipid metabolism as well as in the control of inflammatory responses. Herein we review the main molecular and cellular events associated with the activation of PPARs and their effects on metabolism.
Assuntos
Ácidos Graxos Insaturados/química , Metabolismo dos Lipídeos , Receptores Ativados por Proliferador de Peroxissomo/química , Eicosanoides/química , LigantesRESUMO
Lipid nitration has been observed during oxidative/nitrative stress conditions generating a variety of biomolecules capable of modulating cellular responses. This concept has grown as a result of studies with nitro-derivatives of long-chain unsaturated fatty acids containing a nitroalkene group (nitro-fatty acids). This review focuses on the interactions of nitro-fatty acids with members of the peroxisome proliferator-activated receptors (PPARs) family. These nuclear receptors belong to a superfamily of ligand-activated transcription factors, which serve as sensors of lipophilic molecules and regulate the expression of a set of genes involved in glucose and lipid metabolism. Here we discuss how nitro-fatty acids bind and activate PPARs, including the current knowledge of the molecular interactions and cell signaling events involved as well as their therapeutic potential associated with chronic inflammation and metabolic disorders.
