RESUMEN
Galectin-1 (Gal-1) and galectin-3 (Gal-3) are multifunctional glycan-binding proteins, expressed in the brain and in its limbic structures that are involved in behavioral control. Gal-1 induces the expression of the brain-derived neurotrophic factor (BDNF) and promotes adult neural stem cells proliferation, biological events impaired in stress-related psychiatric disorders, such as depression and anxiety. Despite that, there is no evidence regarding galectin involvement in emotional control during stressful situations. Thus, we analyzed the behavioral phenotype of Gal-1 or Gal-3 knock-out mice (Gal-1 KO or Gal-3 KO) in different experimental models predictive of depressive and compulsive-like behaviors. METHODS: C57BL-6 Gal-1 KO, Gal-3 KO, and wild-type mice (WT) were analyzed under the open field test (OFT) and, 6 h later, under the forced swim test (FST). Additionally, independent groups of male mice, lacking galectins or not, were exposed to the tail suspension test (TST) or to the marble burying test (MBT). The hippocampus and prefrontal cortex (PFC) of the mice submitted to MBT were dissected to access BDNF levels. RESULTS: Both Gal-1 and Gal-3 KO mice showed increased time of immobility in the FST and in the TST compared to WT animals, thus reflecting an impaired stress-coping behavior. Additionally, Gal-1 and Gal-3 KO female mice presented increased compulsive-like behavior in the MBT, without significant changes in the locomotor activity. BDNF levels were found to be decreased in the PFC of Gal-1 KO mice. DISCUSSION: Our results demonstrate that the absence of either endogenous Gal-1 and Gal-3 impairs stress-coping and increases compulsive-like behavior, suggesting that Gal-1 and Gal-3 are involved in the neurobiology of depression and obsessive-compulsive-like disorder.
Asunto(s)
Galectina 1 , Galectina 3 , Estrés Psicológico , Animales , Ansiedad , Conducta Animal , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Conducta Compulsiva , Depresión , Modelos Animales de Enfermedad , Emociones , Femenino , Galectina 1/genética , Galectina 3/genética , Hipocampo/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Inflammation and coagulopathies are important systemic events following snakebite. Snake venom galactoside-binding lectins (SVgalLs) are known modulators of the immune response with no direct effect on hemostasis. Considering the crosstalk between inflammation and coagulation, the present study investigated how BJcuL, a proinflammatory SVgalL isolated from Bothrops jararacussu venom, mediated the inflammation-induced procoagulant activity. We examined the proinflammatory cytokine production and procoagulant tissue factor (TF) activity in human whole blood and monocyte-rich cell suspension (MR-PBMC) treated with BJcuL. This lectin increased production of the cytokines TNF-α, IL-1ß and IL-6, upregulated TF expression on the cell surface, and induced procoagulant activity. The proinflammatory behavior was mediated by the direct interaction between the lectin and toll-like receptor 4, via binding to ß-galactoside-containing glycoconjugates on the cell surface, and activation of NFκ-B signaling. Interestingly, the BJcuL-induced inflammation was directly associated with the procoagulant activity of MR-PBMC cells. In whole blood culture, the lectin exhibited similar behavior, i.e. it induced cytokine production and MR-PBMC TF-mediated procoagulant activity. Therefore, the present study is the first report on the inflammation-induced procoagulant activity of SVgalLs, and it indicates that BJcuL is an important factor associated with coagulopathy in patients with snake envenomation.
Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Bothrops/metabolismo , Venenos de Crotálidos/química , Galectinas/efectos adversos , Inflamación , Animales , Citocinas/efectos de los fármacos , Citocinas/metabolismo , Humanos , Leucocitos Mononucleares/efectos de los fármacosRESUMEN
Parkinson's disease (PD) is the second most common neurodegenerative disorder; however, there is no treatment able to prevent the loss of dopaminergic neurons or its consequences. Trophic factors such as NGF and BDNF has positive effects on different disorders of the brain, including neurodegeneration. Additionally, studies have suggested the use of venom peptides as a therapeutic strategy for neurological disorders. Therefore, in the present study, we investigated the neuroprotective activity of a peptide isolated from Bothrops atrox venom and its trophic ability by using a cellular model of dopaminergic neurotoxicity induced by 1-methyl-4-phenylpyridinium (MPP(+)) in PC12 cells. We showed that it decreased the activities of the apoptotic proteases caspase-9 (mitochondrial) and caspase-3 (executor) and increased cell viability and proliferation in this model. Additionally, it increased neuritogenesis in non-treated PC12 cells (neuronal model) as well as in PC12 cells treated with the dopaminergic neurotoxin. The amino acid sequence of the peptide was identified as Glutamic acid-Valine-Tryptophan (Glu-Val-Trp). These findings suggest that this tripeptide has the potential to protect against the dopaminergic neurons loss and that trophic stimulation of neuroplasticity might be involved in its mechanism of neuroprotection.
Asunto(s)
Bothrops/metabolismo , Fármacos Neuroprotectores/farmacología , Enfermedad de Parkinson/tratamiento farmacológico , Péptidos/farmacología , Ponzoñas/farmacología , 1-Metil-4-fenilpiridinio/farmacología , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Dopamina/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Ácido Glutámico/farmacología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Modelos Biológicos , Células PC12 , Enfermedad de Parkinson/metabolismo , Ratas , Triptófano/farmacología , Valina/farmacologíaRESUMEN
The structures and functional activities of metalloproteinases from snake venoms have been widely studied because of the importance of these molecules in envenomation. Batroxase, which is a metalloproteinase isolated from Bothrops atrox (Pará) snake venom, was obtained by gel filtration and anion exchange chromatography. The enzyme is a single protein chain composed of 202 amino acid residues with a molecular mass of 22.9 kDa, as determined by mass spectrometry analysis, showing an isoelectric point of 7.5. The primary sequence analysis indicates that the proteinase contains a zinc ligand motif (HELGHNLGISH) and a sequence C164 I165M166 motif that is associated with a "Met-turn" structure. The protein lacks N-glycosylation sites and contains seven half cystine residues, six of which are conserved as pairs to form disulfide bridges. The three-dimensional structure of Batroxase was modeled based on the crystal structure of BmooMPα-I from Bothrops moojeni. The model revealed that the zinc binding site has a high structural similarity to the binding site of other metalloproteinases. Batroxase presented weak hemorrhagic activity, with a MHD of 10 µg, and was able to hydrolyze extracellular matrix components, such as type IV collagen and fibronectin. The toxin cleaves both α and ß-chains of the fibrinogen molecule, and it can be inhibited by EDTA, EGTA and ß-mercaptoethanol. Batroxase was able to dissolve fibrin clots independently of plasminogen activation. These results demonstrate that Batroxase is a zinc-dependent hemorrhagic metalloproteinase with fibrin(ogen)olytic and thrombolytic activity.