RESUMEN

Tropomyosin kinase receptor B (TrkB) has been explored as a therapeutic target for neurological and psychiatric disorders. However, the development of TrkB agonists was hindered by our poor understanding of the TrkB agonist binding location and affinity (both affect the regulation of disorder types). This motivated us to develop a combined computational and experimental approach to study TrkB binders. First, we developed a docking method to simulate the binding affinity of TrkB and binders identified by our magnetic drug screening platform from Gotu kola extracts. The Fred Docking scores from the docking computation showed strong agreement with the experimental results. Subsequently, using this screening platform, we identified a list of compounds from the NIH clinical collection library and applied the same docking studies. From the Fred Docking scores, we selected two compounds for TrkB activation tests. Interestingly, the ability of the compounds to increase dendritic arborization in hippocampal neurons matched well with the computational results. Finally, we performed a detailed binding analysis of the top candidates and compared them with the best-characterized TrkB agonist, 7,8-dyhydroxyflavon. The screening platform directly identifies TrkB binders, and the computational approach allows for the quick selection of top candidates with potential biological activities based on the docking scores.

Asunto(s)

Simulación del Acoplamiento Molecular , Enfermedades Neurodegenerativas , Unión Proteica , Receptor trkB , Receptor trkB/metabolismo , Receptor trkB/agonistas , Humanos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Enfermedades Neurodegenerativas/metabolismo , Animales , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/agonistas

RESUMEN

Accumulating evidence has shown that some hallucinogens, such as LSD, have fast and persistent effects on anxiety and depression. According to a proposed mechanism, LSD activates the TrkB and HTR2A signaling pathways, which enhance the density of neuronal dendritic spines and synaptic function, and thus promote brain function. Moreover, TrkB signaling is also known to be crucial for neural stem cell (NSC)-mediated neuroregeneration to repair dysfunctional neurons. However, the impact of LSD on neural stem cells remains to be elucidated. In this study, we observed that LSD and BDNF activated the TrkB pathway in human NSCs similarly to neurons. However, unlike BDNF, LSD did not promote NSC proliferation. These results suggest that LSD may activate an alternative mechanism to counteract the effects of BDNF-TrkB signaling on NSCs. Our findings shed light on the previously unrecognized cell type-specificity of LSD. This could be crucial for deepening our understanding of the mechanisms underlying the effects of LSD.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Alucinógenos , Dietilamida del Ácido Lisérgico , Células-Madre Neurales , Receptor trkB , Transducción de Señal , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Humanos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Alucinógenos/farmacología , Transducción de Señal/efectos de los fármacos , Receptor trkB/metabolismo , Dietilamida del Ácido Lisérgico/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/citología , Glicoproteínas de Membrana

RESUMEN

Synaptic dysfunction is an early pathogenic event leading to cognitive decline in Huntington's disease (HD). We previously reported that the active ADAM10 level is increased in the HD cortex and striatum, causing excessive proteolysis of the synaptic cell adhesion protein N-Cadherin. Conversely, ADAM10 inhibition is neuroprotective and prevents cognitive decline in HD mice. Although the breakdown of cortico-striatal connection has been historically linked to cognitive deterioration in HD, dendritic spine loss and long-term potentiation (LTP) defects identified in the HD hippocampus are also thought to contribute to the cognitive symptoms of the disease. The aim of this study is to investigate the contribution of ADAM10 to spine pathology and LTP defects of the HD hippocampus. We provide evidence that active ADAM10 is increased in the hippocampus of two mouse models of HD, leading to extensive proteolysis of N-Cadherin, which has a widely recognized role in spine morphology and synaptic plasticity. Importantly, the conditional heterozygous deletion of ADAM10 in the forebrain of HD mice resulted in the recovery of spine loss and ultrastructural synaptic defects in CA1 pyramidal neurons. Meanwhile, normalization of the active ADAM10 level increased the pool of synaptic BDNF protein and activated ERK neuroprotective signaling in the HD hippocampus. We also show that the ADAM10 inhibitor GI254023X restored LTP defects and increased the density of mushroom spines enriched with GluA1-AMPA receptors in HD hippocampal neurons. Notably, we report that administration of the TrkB antagonist ANA12 to HD hippocampal neurons reduced the beneficial effect of GI254023X, indicating that the BDNF receptor TrkB contributes to mediate the neuroprotective activity exerted by ADAM10 inhibition in HD. Collectively, these findings indicate that ADAM10 inhibition coupled with TrkB signaling represents an efficacious strategy to prevent hippocampal synaptic plasticity defects and cognitive dysfunction in HD.

Asunto(s)

Proteína ADAM10 , Secretasas de la Proteína Precursora del Amiloide , Hipocampo , Enfermedad de Huntington , Potenciación a Largo Plazo , Proteínas de la Membrana , Receptor trkB , Transducción de Señal , Animales , Proteína ADAM10/metabolismo , Proteína ADAM10/genética , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/patología , Ratones , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Hipocampo/metabolismo , Hipocampo/patología , Receptor trkB/metabolismo , Receptor trkB/antagonistas & inhibidores , Potenciación a Largo Plazo/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Modelos Animales de Enfermedad , Cadherinas/metabolismo , Espinas Dendríticas/metabolismo , Espinas Dendríticas/patología , Neuroprotección , Masculino , Ratones Endogámicos C57BL , Plasticidad Neuronal , Proteínas Tirosina Quinasas/metabolismo , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/genética , Ratones Noqueados

RESUMEN

Opioids are widely used, effective analgesics to manage severe acute and chronic pain, although they have recently come under scrutiny because of epidemic levels of abuse. While these compounds act on numerous central and peripheral pain pathways, the neuroanatomical substrate for opioid analgesia is not fully understood. By means of single-cell transcriptomics and manipulation of morphine-responsive neurons, we have identified an ensemble of neurons in the rostral ventromedial medulla (RVM) that regulates mechanical nociception in mice. Among these, forced activation or silencing of excitatory RVMBDNF projection neurons mimicked or completely reversed morphine-induced mechanical antinociception, respectively, via a brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)-dependent mechanism and activation of inhibitory spinal galanin-positive neurons. Our results reveal a specific RVM-spinal circuit that scales mechanical nociception whose function confers the antinociceptive properties of morphine.

Asunto(s)

Analgésicos Opioides , Factor Neurotrófico Derivado del Encéfalo , Bulbo Raquídeo , Morfina , Neuronas , Nocicepción , Animales , Masculino , Ratones , Analgésicos Opioides/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Bulbo Raquídeo/efectos de los fármacos , Bulbo Raquídeo/metabolismo , Ratones Endogámicos C57BL , Morfina/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/fisiología , Nocicepción/efectos de los fármacos , Receptor trkB/metabolismo , Análisis de la Célula Individual , Médula Espinal/efectos de los fármacos , Transcriptoma , Femenino

RESUMEN

5-Hydroxytryptamine (5-HT) plays a substantial role in mitigating depression and anxiety. However, the potential effects of 5-HT against posttraumatic stress disorder (PTSD) and its underlying mechanisms remain unclear. Elevated plus maze test evaluates anxiety-related behaviors, and the open field test is used to assess overall activity levels and anxiety. Inflammatory cytokine levels were determined using ELISA. The levels of 5-HT and dopamine were measured using HPLC. mRNA and protein levels were examined by PCR and Western blot, respectively. Rats exposed to single prolonged stress (SPS) exhibited typical PTSD-like phenotypes, with decreased levels of 5-HT in the hippocampus and significant reductions in its downstream targets, brain-derived neurotrophic factor (BDNF) and TrkB. In addition, it was discovered that the autophagy signaling pathway might be involved in regulating hippocampal BDNF in rats exposed to SPS. Subsequent treatment with an intracerebral injection of sh-SERT significantly inhibited anxiety and cognitive dysfunction in rats. Moreover, sh-SERT treatment was observed to substantially reverse the increase in autophagy signaling protein expression and consequently improve the expression of BDNF and TrkB proteins, which had been reduced. The current study demonstrates that sh-SERT exhibits significant anti-PTSD effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.NEW & NOTEWORTHY The study demonstrated that sh-SERT exhibits significant anti-posttraumatic stress disorder (PTSD) effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.

Asunto(s)

Autofagia , Factor Neurotrófico Derivado del Encéfalo , Hipocampo , Plasticidad Neuronal , Ratas Sprague-Dawley , Serotonina , Trastornos por Estrés Postraumático , Animales , Trastornos por Estrés Postraumático/tratamiento farmacológico , Trastornos por Estrés Postraumático/metabolismo , Trastornos por Estrés Postraumático/fisiopatología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Autofagia/efectos de los fármacos , Autofagia/fisiología , Plasticidad Neuronal/efectos de los fármacos , Plasticidad Neuronal/fisiología , Masculino , Serotonina/metabolismo , Ratas , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ansiedad/tratamiento farmacológico , Receptor trkB/metabolismo , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Modelos Animales de Enfermedad

RESUMEN

Rice protein peptide (RPP) has been reported to alleviate the symptoms of dextran sulfate sodium (DSS)-induced colitis, but its potential protective effect and fundamental neurobiological mechanisms against DSS-induced inflammatory bowel disease (IBD), coupled with depression and cognitive impairment, remain unclear. In this study, RPP treatment in DSS-induced mice inhibited decreases in body weight and colon length and improved intestinal barrier function and behavioral performance. RPP treatment enhanced phenylalanine and tyrosine metabolism in the brains of mice, and it upregulated metabolites such as l-dopa, phenylethylamine, and 3,4-dihydroxyphenylacetate. Additionally, RPP treatment enhanced the brain-derived neurotrophic factor (BDNF) by upregulating the BDNF/TrkB/CREB signaling pathway. Spearman's correlation analysis revealed that the phenylalanine and tyrosine contents in the brain were significantly negatively correlated with the BDNF/TrkB/CREB signaling pathway and behavioral performance. In conclusion, this study suggested that RPP may serve as a unique nutritional strategy for preventing IBD and its associated cognitive impairment and depression symptoms.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Disfunción Cognitiva , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Depresión , Sulfato de Dextran , Oryza , Péptidos , Fenilalanina , Transducción de Señal , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ratones , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/prevención & control , Masculino , Fenilalanina/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Depresión/metabolismo , Depresión/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Péptidos/administración & dosificación , Humanos , Oryza/química , Oryza/metabolismo , Sulfato de Dextran/efectos adversos , Proteínas de Plantas/metabolismo , Ratones Endogámicos C57BL , Receptor trkB/metabolismo , Colitis/inducido químicamente , Colitis/metabolismo , Colitis/tratamiento farmacológico , Conducta Animal/efectos de los fármacos

RESUMEN

Postmenopausal osteoporosis (PMO) is characterized by bone loss and microstructural damage, and it is most common in older adult women. Currently, there is no cure for PMO. The flavonoid chemical 7,8-dihydroxyflavone (7,8-DHF) specifically activates tropomyosin receptor kinase B (TRKB). Furthermore, 7,8-DHF has various biological characteristics, including anti-inflammatory and antioxidant effects. However, the specific implications and fundamental mechanisms of 7,8-DHF in PMO remain unclear. We used protein imprinting, flow cytometry, tissue staining, and other methods to estimate the preventive mechanisms of 7,8-DHF against hydrogen peroxide (H2O2)-induced apoptosis in primary mouse bone marrow mesenchymal stem cells (BMSCs), osteogenic differentiation ability, and bone mass in ovariectomized (OVX) mice. We found that 7,8-DHF effectively prevented H2O2-induced reductions in the viability and osteogenic differentiation capacity of primary BMSCs. Mechanistically, 7,8-DHF induced the TRKB to activate the PI3K/AKT/NRF2 pathway. In vivo experiments with the OVX mouse model confirmed that 7,8-DHF can inhibit oxidative stress and promote bone formation, indicating that 7,8-DHF improves the viability and osteogenic differentiation ability of BMSCs stimulated via H2O2 by activating the TRKB/PI3K/AKT and NRF2 pathways, thereby improving PMO.

Asunto(s)

Flavonas , Peróxido de Hidrógeno , Células Madre Mesenquimatosas , Factor 2 Relacionado con NF-E2 , Osteogénesis , Osteoporosis Posmenopáusica , Estrés Oxidativo , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Receptor trkB , Transducción de Señal , Animales , Estrés Oxidativo/efectos de los fármacos , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Ratones , Femenino , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Flavonas/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Osteoporosis Posmenopáusica/metabolismo , Osteoporosis Posmenopáusica/patología , Osteoporosis Posmenopáusica/tratamiento farmacológico , Osteogénesis/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Humanos , Receptor trkB/metabolismo , Receptor trkB/genética , Diferenciación Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Ovariectomía , Ratones Endogámicos C57BL

RESUMEN

Depression is a widespread disease, with high mortality and recurrence rates. Recent studies have shown that elevated cytokine levels are implicated in the molecular mechanisms of depression. Oxidative stress contributes to the stimulation of cytokine production. Growing evidence suggests that ginsenoside Re (Gs-Re) exerts a neuroprotective effect on the hippocampus by suppressing oxidative stress and inflammation. However, the effect and mechanism of Gs-Re in the treatment of depression remain understudied. This study aimed to evaluate the neuroprotective and antidepressant-like effects of Gs-Re and the possible underlying mechanisms. In this article, the antidepressant-like effect of the Gs-Re was studied both in vitro (H2O2-induced oxidative stress in HT-22 cells) and in vivo (reserpine-induced depressive model mice). Our results indicated that, at the cellular level, Gs-Re effectively enhanced cell survival following H2O2 stimulation, inhibited the mass production of oxidative stress markers (MDA and ROS), and prevented the occurrence of apoptosis. Moreover, Gs-Re significantly reduced the levels of proinflammatory cytokines IL-1ß, IL-6, and TNF-α and restored the abnormal mitochondrial membrane potential. Subsequently, Gs-Re treatment reversed reserpine-induced neuroinflammation and depressive-like behaviors in vivo and inhibited microglia overactivation. Furthermore, the alterations in the BDNF/TrkB/ERK/CREB signaling pathway induced by H2O2 or reserpine in HT-22 cells or in the mouse hippocampus were significantly reversed by Gs-Re. K252a blocked the improvement of Gs-Re on depression-like behavior and eliminated the inhibition of oxidative stress and neuroinflammation in vivo. This study suggested that Gs-Re produces neuroprotective and depressive effects by inhibiting oxidative stress and inflammation and activating the BDNF/TrkB/ERK/CREB pathway.

Asunto(s)

Antidepresivos , Factor Neurotrófico Derivado del Encéfalo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Depresión , Ginsenósidos , Estrés Oxidativo , Transducción de Señal , Animales , Estrés Oxidativo/efectos de los fármacos , Ginsenósidos/farmacología , Ginsenósidos/administración & dosificación , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Ratones , Depresión/tratamiento farmacológico , Depresión/metabolismo , Masculino , Transducción de Señal/efectos de los fármacos , Antidepresivos/farmacología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Ratones Endogámicos C57BL , Receptor trkB/metabolismo

RESUMEN

Major depressive disorder (MDD) is a complex and devastating illness that affects people of all ages. Despite the large use of antidepressants in current medical practice, neither their mechanisms of action nor the aetiology of MDD are completely understood. Experimental evidence supports the involvement of Parvalbumin-positive GABAergic neurons (PV-neurons) in the pathogenesis of MDD. DLX5 and DLX6 (DLX5/6) encode two homeodomain transcription factors involved in cortical GABAergic differentiation and function. In the mouse, the level of expression of these genes is correlated with the cortical density of PV-neurons and with anxiety-like behaviours. The same genomic region generates the lncRNA DLX6-AS1, which, in humans, participates in the GABAergic regulatory module downregulated in schizophrenia and ASD. Here, we show that the expression levels of Dlx5/6 in the adult mouse brain are correlated with the immobility time in the forced swim test, which is used to measure depressive-like behaviours. We show that the administration of the antidepressant fluoxetine (Flx) to normal mice induces, within 24 h, a rapid and stable reduction in Dlx5, Dlx6 and Dlx6-AS1 expression in the cerebral cortex through the activation of the TrkB-CREB pathway. Experimental Dlx5 overexpression counteracts the antidepressant effects induced by Flx treatment. Our findings show that one of the short-term effects of Flx administration is the reduction in Dlx5/6 expression in GABAergic neurons, which, in turn, has direct consequences on PV expression and on behavioural profiles. Variants in the DLX5/6 regulatory network could be implicated in the predisposition to depression and in the variability of patients' response to antidepressant treatment.

Asunto(s)

Antidepresivos , Corteza Cerebral , Fluoxetina , Neuronas GABAérgicas , Proteínas de Homeodominio , Receptor trkB , Animales , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/efectos de los fármacos , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/genética , Fluoxetina/farmacología , Fluoxetina/uso terapéutico , Ratones , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/patología , Corteza Cerebral/metabolismo , Receptor trkB/metabolismo , Receptor trkB/genética , Masculino , Transducción de Señal/efectos de los fármacos , Ratones Endogámicos C57BL , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/patología , Trastorno Depresivo Mayor/genética

RESUMEN

Age-related conditions, such as sarcopenia, cause physical disabilities for an increasing section of society. At the neuromuscular junction, the postsynaptic-derived neurotrophic factors brain-derived neurotrophic factor (BDNF) and neurotrophin 4 (NT-4) have neuroprotective functions and contribute to the correct regulation of the exocytotic machinery. Similarly, presynaptic muscarinic signalling plays a fundamental modulatory function in this synapse. However, whether or not these signalling pathways are compromised in ageing neuromuscular system has not yet been analysed. The present study analyses, through Western blotting, the differences in expression and activation of the main key proteins of the BDNF/NT-4 and muscarinic pathways related to neurotransmission in young versus ageing Extensor digitorum longus (EDL) rat muscles. The main results show an imbalance in several sections of these pathways: (i) a change in the stoichiometry of BDNF/NT-4, (ii) an imbalance of Tropomyosin-related kinase B receptor (TrkB)-FL/TrkB-T1 and neurotrophic receptor p 75 (p75NTR), (iii) no changes in the cytosol/membrane distribution of phosphorylated downstream protein kinase C (PKC)ßI and PKCε, (iv) a reduction in the M2-subtype muscarinic receptor and P/Q-subtype voltage-gated calcium channel, (v) an imbalance of phosphorylated mammalian uncoordinated-18-1 (Munc18-1) (S313) and synaptosomal-associated protein 25 (SNAP-25) (S187), and (vi) normal levels of molecules related to the management of acetylcholine (Ach). Based on this descriptive analysis, we hypothesise that these pathways can be adjusted to ensure neurotransmission rather than undergoing negative alterations caused by ageing. However, further studies are needed to assess this hypothetical suggestion. Our results contribute to the understanding of some previously described neuromuscular functional age-related impairments. Strategies to promote these signalling pathways could improve the neuromuscular physiology and quality of life of older people.

Asunto(s)

Envejecimiento , Factor Neurotrófico Derivado del Encéfalo , Unión Neuromuscular , Receptor trkB , Transducción de Señal , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Animales , Unión Neuromuscular/metabolismo , Envejecimiento/metabolismo , Ratas , Receptor trkB/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Masculino , Receptores Muscarínicos/metabolismo , Transmisión Sináptica , Receptores de Factor de Crecimiento Nervioso/metabolismo , Ratas Wistar

RESUMEN

Brain-derived neurotrophic factor (BDNF) content and signaling has been identified as one potential regulator of amyloid precursor protein (APP) processing. Recently published work has demonstrated that BDNF reduces BACE1 activity while also elevating the inhibition of GSK3ß in the prefrontal cortex of male C57BL/6J mice. These results provide evidence that BDNF alters APP processing by reducing BACE1 activity, which may act through GSK3ß inhibition. The purpose of this study was to further explore the role of GSK3ß in BDNF-induced regulation on BACE1 activity. We utilized a cell culture and an in vitro activity assay model to pharmacologically target BDNF and GSK3ß signaling to confirm its involvement in the BDNF response. Treatment of differentiated SH-SY5Y neuronal cells with 75 ng/mL BDNF resulted in elevated pTrkB content, pAkt content, pGSK3ß content, and reduced BACE1 activity. An in vitro BACE1 activity assay utilizing mouse prefrontal cortex (n = 6/group) supplemented with BDNF, BDNF + ANA12 (Trkb antagonist), or BDNF + wortmannin (Akt inhibitor) demonstrated that BDNF reduced BACE1 activity; however, in the presence of TrkB or Akt inhibition, this effect was abolished. An in vitro ADAM10 activity assay utilizing mouse prefrontal cortex (n = 6/group) supplemented with BDNF, BDNF + ANA12 (Trkb antagonist), or BDNF + wortmannin (Akt inhibitor) demonstrated that BDNF did not alter ADAM10 activity. However, inhibiting BDNF signaling reduced ADAM10 activity. Collectively these studies suggest that GSK3ß inhibition may be necessary for BDNF-induced reductions in BACE1 activity. These findings will allow for the optimization of future therapeutic strategies by selectively targeting TrkB activation and GSK3ß inhibition.

Asunto(s)

Secretasas de la Proteína Precursora del Amiloide , Ácido Aspártico Endopeptidasas , Factor Neurotrófico Derivado del Encéfalo , Glucógeno Sintasa Quinasa 3 beta , Ratones Endogámicos C57BL , Neuronas , Proteínas Proto-Oncogénicas c-akt , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Humanos , Ácido Aspártico Endopeptidasas/metabolismo , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ratones , Masculino , Corteza Prefrontal/metabolismo , Corteza Prefrontal/efectos de los fármacos , Transducción de Señal , Línea Celular Tumoral , Receptor trkB/metabolismo , Receptor trkB/antagonistas & inhibidores , Glicoproteínas de Membrana/metabolismo

RESUMEN

Tropomyosin receptor kinases (Trks) are transmembrane receptor tyrosine kinases named TrkA, TrkB, and TrkC and encoded by the NTRK1, NTRK2, and NTRK3 genes, respectively. These kinases have attracted significant attention and represent a promising therapeutic target for solid tumor treatment due to their vital role in cellular signaling pathways. First-generation TRK inhibitors, i.e., Larotrectinib sulfate and Entrectinib, received clinical approval in 2018 and 2019, respectively. However, the use of these inhibitors was significantly limited because of the development of resistance due to mutations. Fortunately, the second-generation Trk inhibitor Repotrectinib (TPX-0005) was approved by the FDA in November 2023, while Selitrectinib (Loxo-195) has provided an effective solution to this issue. Another macrocycle-based analog, along with many other TRK inhibitors, is currently in clinical trials. Two of the three marketed drugs for NTRK fusion cancers feature a pyrazolo[1,5-a] pyrimidine nucleus, prompting medicinal chemists to develop numerous novel pyrazolopyrimidine-based molecules to enhance clinical applications. This article focuses on a comprehensive review of chronological synthetic developments and the structure-activity relationships (SAR) of pyrazolo[1,5-a]pyrimidine derivatives as Trk inhibitors. This article will also provide comprehensive knowledge and future directions to the researchers working in the field of medicinal chemistry by facilitating the structural modification of pyrazolo [1,5-a]pyrimidine derivatives to synthesize more effective novel chemotherapeutics as TRK inhibitors.

Asunto(s)

Inhibidores de Proteínas Quinasas , Pirazoles , Pirimidinas , Receptor trkA , Pirimidinas/química , Pirimidinas/farmacología , Pirimidinas/síntesis química , Humanos , Pirazoles/química , Pirazoles/farmacología , Pirazoles/síntesis química , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/uso terapéutico , Relación Estructura-Actividad , Receptor trkA/antagonistas & inhibidores , Receptor trkA/metabolismo , Receptor trkA/genética , Receptor trkB/antagonistas & inhibidores , Receptor trkB/metabolismo , Receptor trkC/antagonistas & inhibidores , Receptor trkC/genética , Receptor trkC/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/enzimología , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química

RESUMEN

Clinical evidence suggests that early malnutrition promotes symptoms related to psychiatric disorders later in life. Nevertheless, the molecular mechanisms underpinning nutritional injury induce depression remains unknown. The purpose of the present study was to evaluate whether perinatal protein restriction increases vulnerability to developing depressive-like behavior in adulthood by focusing on anhedonia, a core symptom of depression. To this, male adult Wistar rats submitted to a protein restriction schedule at perinatal age (PR-rats), were subjected to the sucrose preference test (SPT), the novel object recognition test (NORT), the forced swim test (FST), and the elevated plus maze (EPM), and compared to animals fed with a normoprotein diet. To investigate neurobiological substrates linked to early protein undernutrition-facilitated depressive-like behavior, we assessed the levels of brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the nucleus accumbens (NAc), and evaluated the reversal of anhedonic-like behavior by infusing ANA-12. We found that early malnutrition decreased sucrose preference, impaired performance in the NORT and increased immobility time in the FST. Furthermore, perinatal protein-restriction-induced anhedonia correlated with increased BDNF and p-TrkB protein levels in the NAc, a core structure in the reward circuit linked with anhedonia. Finally, bilateral infusion of the TrkB antagonist ANA-12 into the NAc shell ameliorated a reduced sucrose preference in the PR-rats. Altogether, these findings revealed that protein restriction during pregnancy and lactation facilitates depressive-like behavior later in life and may increase the risk of developing anhedonia by altering BDNF-TrkB in the NAc shell.

Asunto(s)

Anhedonia , Factor Neurotrófico Derivado del Encéfalo , Núcleo Accumbens , Ratas Wistar , Receptor trkB , Transducción de Señal , Animales , Núcleo Accumbens/metabolismo , Núcleo Accumbens/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Masculino , Anhedonia/fisiología , Ratas , Receptor trkB/metabolismo , Femenino , Transducción de Señal/fisiología , Transducción de Señal/efectos de los fármacos , Embarazo , Dieta con Restricción de Proteínas , Efectos Tardíos de la Exposición Prenatal/metabolismo , Depresión/metabolismo , Depresión/psicología , Azepinas , Benzamidas

RESUMEN

Two cases of complicated pain exist: posterior screw fixation and myofascial pain. Intramuscular pulsed radiofrequency (PRF) may be an alternative treatment for such patients. This is a two-stage animal study. In the first stage, two muscle groups and two nerve groups were subdivided into a high-temperature group with PRF at 58 °C and a regular temperature with PRF at 42 °C in rats. In the second stage, two nerve injury groups were subdivided into nerve injury with PRF 42 °C on the sciatic nerve and muscle. Blood and spinal cord samples were collected. In the first stage, the immunohistochemical analysis showed that PRF upregulated brain-derived neurotrophic factor (BDNF) in the spinal cord in both groups of rats. In the second stage, the immunohistochemical analysis showed significant BDNF and tropomyosin receptor kinase B (TrkB) expression within the spinal cord after PRF in muscles and nerves after nerve injury. The blood biomarkers showed a significant increase in BDNF levels. PRF in the muscle in rats could upregulate BDNF-TrkB in the spinal cord, similar to PRF on the sciatica nerve for pain relief in rats. PRF could be considered clinically for patients with complicated pain and this study also demonstrated the role of BDNF in pain modulation. The optimal temperature for PRF was 42 °C.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Tratamiento de Radiofrecuencia Pulsada , Receptor trkB , Médula Espinal , Regulación hacia Arriba , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Receptor trkB/metabolismo , Ratas , Médula Espinal/metabolismo , Tratamiento de Radiofrecuencia Pulsada/métodos , Masculino , Ratas Sprague-Dawley , Manejo del Dolor/métodos , Nervio Ciático/metabolismo , Nervio Ciático/lesiones , Dolor/metabolismo , Dolor/etiología

RESUMEN

OBJECTIVE: Acute-on-chronic liver failure (ACLF) is a syndrome characterized by a high short-term mortality rate, and effective interventions are still lacking. This study aims to investigate whether the small molecule baicalein can mitigate ACLF and elucidate the molecular mechanisms. METHODS: The ACLF mouse model was induced through chronic liver injury using carbon tetrachloride, followed by acute inflammation induction with lipopolysaccharide (LPS). Baicalein was administered through intraperitoneal injection to explore its therapeutic effects. In vitro experiments utilized the iBMDM macrophage cell line to investigate the underlying mechanisms. Peripheral blood was collected from clinical ACLF patients for validation. RESULTS: In the LPS-induced ACLF mouse model, baicalein demonstrated a significant reduction in acute inflammation and liver damage, as evidenced by histopathological evaluation, liver function analysis, and inflammatory marker measurements. Transcriptomic analysis, coupled with molecular biology experiments, uncovered that baicalein exerts its effects in ACLF by activating the TrKB-CREB1 signaling axis to upregulate the surface expression of the TREM2 receptor on macrophages. This promotes M2 macrophage polarization and activates efferocytosis, thereby inhibiting inflammation and alleviating liver damage. Furthermore, we observed a substantial negative correlation between postoperative peripheral blood plasma soluble TREM2 (sTREM2) levels and inflammation, as well as adverse outcomes in clinical ACLF patients. CONCLUSION: Baicalein plays a protective role in ACLF by enhancing the surface expression of the TREM2 receptor on macrophages, leading to the suppression of inflammation, mitigation of liver damage, and a reduction in mortality. Additionally, plasma sTREM2 emerges as a critical indicator for predicting adverse outcomes in ACLF patients.

Asunto(s)

Insuficiencia Hepática Crónica Agudizada , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Flavanonas , Macrófagos , Glicoproteínas de Membrana , Ratones Endogámicos C57BL , Receptores Inmunológicos , Transducción de Señal , Insuficiencia Hepática Crónica Agudizada/tratamiento farmacológico , Animales , Flavanonas/farmacología , Flavanonas/uso terapéutico , Humanos , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Masculino , Receptores Inmunológicos/metabolismo , Receptores Inmunológicos/genética , Glicoproteínas de Membrana/metabolismo , Ratones , Transducción de Señal/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/inmunología , Lipopolisacáridos , Regulación hacia Arriba/efectos de los fármacos , Receptor trkB/metabolismo , Modelos Animales de Enfermedad , Persona de Mediana Edad , Femenino , Línea Celular , Adulto , Proteínas Tirosina Quinasas/metabolismo , Hígado/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Antiinflamatorios/uso terapéutico , Antiinflamatorios/farmacología

RESUMEN

BACKGROUND: Emerging data has demonstrated that in mature neurons, SorCS2 localizes to the postsynaptic density of dendritic spines and facilitates plasma membrane sorting of TrkB by interacting with it, transmitting positive signaling from BDNF on neurons. Thus, it is possible that SorCS2 plays a role in the pathophysiology of depression by regulating the BDNF-TrkB system. METHODS: In the present study, SorCS2 expression in different brain regions [hippocampus, medial prefrontal cortex (mPFC), hypothalamus, amygdala, ventral tegmental area (VTA), and nucleus accumbens (NAc)] was thoroughly investigated in the chronic social defeat stress (CSDS) and chronic unpredictable mild stress (CUMS) models of depression. The changes in depressive-like behaviors, the hippocampal BDNF signaling cascade, and amounts of hippocampal immature neurons were further investigated after SorCS2 overexpression by microinjection of the adenovirus associated virus vector containing the coding sequence of mouse SorCS2 (AAV-SorCS2) into the hippocampus of mice exposed to CSDS or CUMS. RESULTS: It was found that both CSDS and CUMS significantly decreased the protein and mRNA expression of SorCS2 in the hippocampus but not in other brain regions. Chronic stress also notably downregulated the level of hippocampal SorCS2-TrkB binding in mice. In contrast, AAV-based genetic overexpression of hippocampal SorCS2 fully reversed the chronic stress-induced not only depressive-like behaviors but also decreased SorCS2-TrkB binding, BDNF signaling pathway, and amounts of immature neurons in the hippocampus of mice. CONCLUSION: All these results suggest that enhancing the hippocampal SorCS2 expression protects against chronic stress, producing antidepressant-like actions. Hippocampal SorCS2 may participate in depression neurobiology and be a potential antidepressant target. SIGNIFICANCE STATEMENT: Targeting of proteins to distinct subcellular compartments is essential for neuronal activity and modulated by VPS10P domain receptors which include SorCS2. In mature neurons, SorCS2 localizes to the postsynaptic density of dendritic spines and facilitates plasma membrane sorting of TrkB by interacting with it, transmitting positive signaling from BDNF on neurons. Our study is the first direct evidence preliminarily showing that SorCS2 plays a role in depression neurobiology. It was found that chronic stress induced not only depressive-like behaviors but also decreased SorCS2 expression in the hippocampus. Chronic stress did not affect SorCS2 expression in the mPFC, hypothalamus, amygdala, VTA, or NAc. In contrast, genetic overexpression of hippocampal SorCS2 prevented against chronic stress, producing antidepressant-like actions in mice. Thus, hippocampal SorCS2 is a potential participant underlying depression neurobiology and may be a novel antidepressant target. Our study may also extend the knowledge of the neurotrophic hypothesis of depression.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Depresión , Hipocampo , Ratones Endogámicos C57BL , Receptor trkB , Estrés Psicológico , Animales , Masculino , Ratones , Conducta Animal , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Depresión/metabolismo , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Neuronas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Proteínas Tirosina Quinasas/genética , Receptor trkB/metabolismo , Transducción de Señal , Estrés Psicológico/metabolismo

RESUMEN

Premature ovarian failure (POF) is characterized by a significant decline in the ovarian follicle pool and oocyte reserve, alongside an increase in the number of low-quality oocytes and apoptosis of granulosa cells (GCs). Exosome-derived miRNA plays a regulatory role in crucial cellular activities and contributes to the onset and progression of POF. In this study, we successfully established a rabbit model of POF and conducted in vitro and in vivo experiments that confirmed DiI-labeled Pla-Exos (exosomes derived from plasma) could enter the follicle through blood circulation, with GCs capable of uptaking these exosomes. Our RNA-seq analysis revealed elevated expression of miR-10a-5p in Pla-Exos from POF rabbits. Moreover, our findings demonstrate that exosomal miR-10a-5p suppresses GCs proliferation and induces apoptosis via the mitochondrial pathway. Additionally, exosomal miR-10a-5p inhibits the TrkB/Akt/mTOR signaling pathway by downregulating BDNF expression, thereby modulating the expression levels of proteins and genes associated with the cell cycle, follicle development, and GCs senescence. In conclusion, our study highlights the role of Pla-Exos miR-10a-5p in promoting rabbit POF through the TrkB/Akt/mTOR signaling pathway by targeting BDNF. These findings provide new insights into potential therapeutic targets for POF, offering valuable references for addressing concerns related to female reproductive function.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Exosomas , Células de la Granulosa , MicroARNs , Insuficiencia Ovárica Primaria , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Serina-Treonina Quinasas TOR , Animales , Femenino , Exosomas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Insuficiencia Ovárica Primaria/genética , Insuficiencia Ovárica Primaria/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Conejos , Células de la Granulosa/metabolismo , Receptor trkB/metabolismo , Receptor trkB/genética , Apoptosis/genética , Proliferación Celular , Humanos , Folículo Ovárico/metabolismo

RESUMEN

BACKGROUND: Protein kinase A (PKA) enhances neurotransmission at the neuromuscular junction (NMJ), which is retrogradely regulated by nerve-induced muscle contraction to promote Acetylcholine (ACh) release through the phosphorylation of molecules involved in synaptic vesicle exocytosis (SNAP-25 and Synapsin-1). However, the molecular mechanism of the retrograde regulation of PKA subunits and its targets by BDNF/TrkB pathway and muscarinic signalling has not been demonstrated until now. At the NMJ, retrograde control is mainly associated with BDNF/TrkB signalling as muscle contraction enhances BDNF levels and controls specific kinases involved in the neurotransmission. Neurotransmission at the NMJ is also highly modulated by muscarinic receptors M1 and M2 (mAChRs), which are related to PKA and TrkB signallings. Here, we investigated the hypothesis that TrkB, in cooperation with mAChRs, regulates the activity-dependent dynamics of PKA subunits to phosphorylate SNAP-25 and Synapsin-1. METHODS: To explore this, we stimulated the rat phrenic nerve at 1Hz (30 minutes), with or without subsequent contraction (abolished by µ-conotoxin GIIIB). Pharmacological treatments were conducted with the anti-TrkB antibody clone 47/TrkB for TrkB inhibition and exogenous h-BDNF; muscarinic inhibition with Pirenzepine-dihydrochloride and Methoctramine-tetrahydrochloride for M1 and M2 mAChRs, respectively. Diaphragm protein levels and phosphorylation' changes were detected by Western blotting. Location of the target proteins was demonstrated using immunohistochemistry. RESULTS: While TrkB does not directly impact the levels of PKA catalytic subunits Cα and Cß, it regulates PKA regulatory subunits RIα and RIIß, facilitating the phosphorylation of critical exocytotic targets such as SNAP-25 and Synapsin-1. Furthermore, the muscarinic receptors pathway maintains a delicate balance in this regulatory process. These findings explain the dynamic interplay of PKA subunits influenced by BDNF/TrkB signalling, M1 and M2 mAChRs pathways, that are differently regulated by pre- and postsynaptic activity, demonstrating the specific roles of the BDNF/TrkB and muscarinic receptors pathway in retrograde regulation. CONCLUSION: This complex molecular interplay has the relevance of interrelating two fundamental pathways in PKA-synaptic modulation: one retrograde (neurotrophic) and the other autocrine (muscarinic). This deepens the fundamental understanding of neuromuscular physiology of neurotransmission that gives plasticity to synapses and holds the potential for identifying therapeutic strategies in conditions characterized by impaired neuromuscular communication.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Proteínas Quinasas Dependientes de AMP Cíclico , Unión Neuromuscular , Receptor trkB , Transducción de Señal , Sinapsinas , Proteína 25 Asociada a Sinaptosomas , Animales , Masculino , Ratas , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Unión Neuromuscular/metabolismo , Fosforilación , Ratas Wistar , Receptor trkB/metabolismo , Receptores Muscarínicos/metabolismo , Sinapsinas/metabolismo , Proteína 25 Asociada a Sinaptosomas/metabolismo

RESUMEN

Trk (NTRK) receptor and NTRK gene fusions are oncogenic drivers of a wide variety of tumors. Although Trk receptors are typically activated at the cell surface, signaling of constitutive active Trk and diverse intracellular NTRK fusion oncogenes is barely investigated. Here, we show that a high intracellular abundance is sufficient for neurotrophin-independent, constitutive activation of TrkB kinase domains. In HEK293 cells, constitutive active TrkB kinase and an intracellular NTRK2-fusion oncogene (SQSTM1-NTRK2) reduced actin filopodia dynamics, phosphorylated FAK, and altered the cell morphology. Atypical cellular responses could be mimicked with the intracellular kinase domain, which did not activate the Trk-associated MAPK/ERK pathway. In glioblastoma-like U87MG cells, expression of TrkB or SQSTM1-NTRK2 reduced cell motility and caused drastic changes in the transcriptome. Clinically approved Trk inhibitors or mutating Y705 in the kinase domain, blocked the cellular effects and transcriptome changes. Atypical signaling was also seen for TrkA and TrkC. Moreover, hallmarks of atypical pTrk kinase were found in biopsies of Nestin-positive glioblastoma. Therefore, we suggest Western blot-like immunoassay screening of NTRK-related (brain) tumor biopsies to identify patients with atypical panTrk or phosphoTrk signals. Such patients could be candidates for treatment with NTRK inhibitors such as Larotrectinhib or Entrectinhib.

Asunto(s)

Proteínas de Fusión Oncogénica , Receptor trkB , Humanos , Receptor trkB/metabolismo , Receptor trkB/genética , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Línea Celular Tumoral , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Células HEK293 , Transducción de Señal , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Movimiento Celular/genética

RESUMEN

Various mechanisms through which maternal diet influences offspring brain development in gestational diabetes mellitus (GDM) remains unclear. We speculate that prenatal omega 3 fatty acids will improve the levels of brain neurotrophins and vascular endothelial growth factor (VEGF), an angiogenic factor leading to improved cognitive performance in the offspring. GDM was induced in Wistar rats using streptozotocin. They were assigned to either control, GDM or GDM+O (GDM + omega-3 fatty acid supplementation). The offspring were followed till 3 mo of age and cognitive assessment was undertaken. Data analysis was carried out using one-way ANOVA followed by LSD test. GDM induction increased (p < 0.01) dam glucose levels and lowered brain derived neurotrophic factor (BDNF) levels (p = 0.056) in the offspring at birth. At 3 months, GDM group showed significantly lower levels of neurotrophic tyrosine kinase receptor-2 (NTRK-2) and VEGF, lower mRNA levels of NTRK-2 and cAMP response element-binding protein (CREB) (P < 0.05 for all) as compared to control. The GDM offspring had a higher escape latency (p < 0.01), made lesser % correct choices and more errors (p < 0.05 for both). Prenatal supplementation with omega 3 polyunsaturated fatty acids was beneficial since it ameliorated some of the adverse effects of GDM.

Asunto(s)

Factor Neurotrófico Derivado del Encéfalo , Encéfalo , Diabetes Gestacional , Ácidos Grasos Omega-3 , Ratas Wistar , Factor A de Crecimiento Endotelial Vascular , Animales , Embarazo , Diabetes Gestacional/metabolismo , Ácidos Grasos Omega-3/farmacología , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Ratas , Suplementos Dietéticos , Receptor trkB/metabolismo , Receptor trkB/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Diabetes Mellitus Experimental/metabolismo , Masculino , Glucemia/metabolismo