RESUMO
Individuals with diabetes mellitus (DM) tend to manifest anxiety and depression, which could be related to changes in the expression of calcium/calmodulin-dependent protein kinase IV (CaMKIV), transcription factor cyclic AMP-responsive element binding protein (CREB), phosphorylated CREB (pCREB) and brain-derived neurotrophic factor (BDNF) in different brain regions. The objective of this study was to determine whether mice with type 1 diabetes (T1DM) induced with streptozotocin show a profile of anxious-type behaviors and alterations in the expression/activity of CaMKIV, CREB, pCREB and BDNF in different regions of the brain (prefrontal cortex, amygdala, hippocampus and hypothalamus) in comparison to non-diabetic mice (NDB). Mice with 3 months of chronic DM showed an anxious-like behavioral profile in two anxiety tests (Open Field and Elevated Plus Maze), when compared to NDB. There were significant differences in the expression of cell signaling proteins: diabetic mice had a lower expression of CaMKIV in the hippocampus, a greater expression of CREB in the amygdala and hypothalamus, as well as a lower pCREB/CREB in hypothalamus than NDB mice (P < 0.05). This is the first study evaluating the expression of CaMKIV in the brain of animals with DM, who presented lower expression of this protein in the hippocampus. In addition, it is the first time that CREB was evaluated in amygdala and hypothalamus of animals with DM, who presented a higher expression. Further research is necessary to determine the possible link between expression of CaMKIV and CREB, and the behavioral profile of anxiety in diabetic animals.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Diabetes Mellitus , Tonsila do Cerebelo , Animais , Ansiedade/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cálcio/metabolismo , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Diabetes Mellitus/metabolismo , Hipocampo/metabolismo , Hipotálamo/metabolismo , Camundongos , Córtex Pré-Frontal/metabolismo , Transdução de Sinais , Estreptozocina/metabolismoRESUMO
CCDC28B (coiled-coil domain-containing protein 28B) was identified as a modifier in the ciliopathy Bardet-Biedl syndrome (BBS). Our previous work in cells and zebrafish showed that CCDC28B plays a role regulating cilia length in a mechanism that is not completely understood. Here we report the generation of a Ccdc28b mutant mouse using CRISPR/Cas9 (Ccdc28b mut). Depletion of CCDC28B resulted in a mild phenotype. Ccdc28b mut animals i) do not present clear structural cilia affectation, although we did observe mild defects in cilia density and cilia length in some tissues, ii) reproduce normally, and iii) do not develop retinal degeneration or obesity, two hallmark features of reported BBS murine models. In contrast, Ccdc28b mut mice did show clear social interaction defects as well as stereotypical behaviors. This finding is indeed relevant regarding CCDC28B as a modifier of BBS since behavioral phenotypes have been documented in BBS. Overall, this work reports a novel mouse model that will be key to continue evaluating genetic interactions in BBS, deciphering the contribution of CCDC28B to modulate the presentation of BBS phenotypes. In addition, our data underscores a novel link between CCDC28B and behavioral defects, providing a novel opportunity to further our understanding of the genetic, cellular, and molecular basis of these complex phenotypes.
Assuntos
Síndrome de Bardet-Biedl , Degeneração Retiniana , Animais , Síndrome de Bardet-Biedl/genética , Síndrome de Bardet-Biedl/metabolismo , Cílios/metabolismo , Camundongos , Fenótipo , Degeneração Retiniana/genética , Peixe-Zebra/genéticaRESUMO
The melanin-concentrating hormone (MCH) is a peptidergic neuromodulator synthesized by neurons of the posterior hypothalamus and incerto-hypothalamic area. These neurons project throughout the central nervous system, including the dorsal raphe nucleus (DRN). In rodents, MCH exerts its biological functions through the MCHR-1 receptor. We previously demonstrated that intra-DRN MCH administration increases REM sleep time and induces a pro-depressive behavior. We also determined that MCH modulates the neuronal firing rate and serotonin release within this nucleus. Previous studies in mice identified the presence of MCHR-1 in neurons located in the olfactory tubercle, hypothalamus, and nucleus accumbens, in a specialized neuronal appendage: the neuronal primary cilia. However, the subcellular location of MCHR-1 protein in the DRN is still unknown. Hence, the aim of the present study was to explore, by means of single and double immunohistochemical procedures, whether MCHR-1 is present in neuronal primary cilia in serotonergic and GABAergic neurons located in the DRN of the rat. We demonstrated colocalization of MCHR-1 with type III adenylyl cyclase (AC-III), a neuronal ciliary marker, in the DRN and confirmed their colocalization in the hippocampus and cerebral cortex of the rat. We quantified the proportion of serotoninergic and GABAergic neurons that coexpress MCHR-1 at the mid-caudal and mid-rostral levels of the DRN: 4% and 12%, respectively. Furthermore, approximately 10% of the total number of MCHR-1 immunoreactive primary cilia belonged to serotonergic neurons, whilst 12% were appendages of GABAergic neurons. These morphological data allow us to conclude that the mechanism by which MCH modulates the activity of DRN neurons is through MCHR-1 receptors present in the primary cilia of different neurochemical phenotypes. New experiments are needed to understand the functional rationale of the unexpected localization of these receptors and to explore their presence in other neuronal phenotypes.