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The incidence and clinical distribution of intracranial haemorrhage (ICH) in neonates at risk of cerebral hypoxia-ischaemia have not been reported in specific studies. Based on conventional magnetic resonance imaging (MRI) versus susceptibility weighted imaging (SWI), this study aimed to analyse the occurrence of asymptomatic ICH in newborns with or without risk of cerebral hypoxia-ischaemia and to accumulate objective data for clinical evaluations of high-risk neonates and corresponding response strategies. 317 newborns were included. MRI revealed that the overall incidence of ICH was 59.31%. The most common subtype was intracranial extracerebral haemorrhage (ICECH) which included subarachnoid haemorrhage (SAH) and subdural haemorrhage (SDH). ICECH accounted for 92.02% of ICH. The positive detection rate of ICECH by SWI was significantly higher than that by T1WI. The incidence of total ICH, ICECH and SAH was greater among children who were delivered vaginally than among those who underwent caesarean delivery. Asymptomatic neonatal ICH may be a common complication of the neonatal birth process, and SWI may improve the detection rate. Transvaginal delivery and a weight greater than 2500 g were associated with a high incidence of ICECH in neonates. The impact of neonatal cerebral hypoxia-ischaemia risk factors on the occurrence of asymptomatic ICH may be negligible.
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Hipoxia-Isquemia Encefálica , Hemorragias Intracraneales , Imagen por Resonancia Magnética , Humanos , Recién Nacido , Femenino , Imagen por Resonancia Magnética/métodos , Incidencia , Masculino , Hemorragias Intracraneales/diagnóstico por imagen , Hemorragias Intracraneales/epidemiología , Hemorragias Intracraneales/etiología , Hipoxia-Isquemia Encefálica/diagnóstico por imagen , Hipoxia-Isquemia Encefálica/epidemiología , Hipoxia-Isquemia Encefálica/complicaciones , Factores de RiesgoRESUMEN
PURPOSE: To observe the regulation of cerebral circulation in vivo based on image segmentation algorithms for deep learning in medical imaging to automatically detect and quantify the neonatal deep medullary veins (DMVs) on susceptibility weighted imaging (SWI) images. To evaluate early cerebral circulation self-rescue for neonates undergoing risk of cerebral hypoxia-ischaemia in vivo. METHODS: SWI images and clinical data of 317 neonates with or without risk of cerebral hypoxia-ischaemia were analyzed. Quantitative parameters showing the number, width, and curvature of DMVs were obtained using an image segmentation algorithm. RESULTS: The number of DMVs was greater in males than in females (pâ¯< 0.01), and in term than in preterm infants (pâ¯= 0.001). The width of DMVs was greater in term than in preterm infants (pâ¯< 0.01), in low-risk than in high-risk group (pâ¯< 0.01), and in neonates without intracranial extracerebral haemorrhage (ICECH) than with ICECH (pâ¯< 0.05). The curvature of DMVs was greater in term than in preterm infants (Pâ¯< 0.05). The width of both bilateral thalamic veins and anterior caudate nucleus veins were positively correlated with the number of DMVs; the width of bilateral thalamic veins was positively correlated with the width of DMVs. CONCLUSION: The DMVs quantification based on image segmentation algorithm may provide more detailed and stable quantitative information in neonate. SWI vein quantification may be an observable indicator for in vivo assessment of cerebral circulation self-regulation in neonatal hypoxic-ischemic brain injury.
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Acute kidney injury (AKI) is a critical condition with a mortality rate as high as 50% and significantly contributes to the burden of end-stage renal disease (ESRD) requiring renal replacement therapy. The incidence and prognosis of AKI have been shown to vary with patient age, with younger individuals being more resistant to AKI. In mice, clamping the renal artery for 45 min causes substantial kidney damage in 4-month-old animals but only mild renal injury in 2-month-old animals. Here, younger mice were found to express higher levels of the NAD(+)-dependent histone deacetylase SIRT1 in the kidney. A small molecule SIRT1 activator, SRT-1720, markedly improved renal tubular pathology and overall renal function in adult mice following ischemia/reperfusion. Genetic ablation of one allele (SIRT1(+/-)) significantly enhanced the level of kidney damage relative to that in wild-type (SIRT1(+/+)) mice. The mechanisms underlying the protective effect of SIRT1 included the suppression of cell apoptosis. Hence, our results suggest that SIRT1 might be a novel therapeutic target for ischemia/reperfusion-induced kidney damage.
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Lesión Renal Aguda/etiología , Riñón/irrigación sanguínea , Daño por Reperfusión/complicaciones , Sirtuina 1/fisiología , Animales , Apoptosis , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Sirtuina 1/análisis , Sirtuina 1/genética , Proteína p53 Supresora de Tumor/análisisRESUMEN
It is believed that neonatal hypoxia-ischemia (HI) brain injury causes neuron loss and brain functional defects. However, the effect of HI brain injury on dendritic development of the remaining pyramidal cells of the hippocampus and the reaction of contralateral hippocampal neurons require further studies. The Morris water maze and Golgi-Cox staining were used to evaluate the learning and memory and dendritic morphology of pyramidal cells. The results of Golgi-Cox staining showed CA1 pyramidal neurons of HI injury models with fewer bifurcations and shorter dendrite length than the naive control group. The density of dendritic spines of hippocampal CA1 pyramidal neurons was significantly lower in the HI brain injury group than in controls. With respect to hippocampal function, the HI brain injury group presented cognitive deficits in the reference memory task and probe trail. In the HI group, the pyramidal cells of left hippocampus that did not experienced ischemia but did experience hypoxia had more complex dendrites and higher density of spine than the HI injury side and control. The functional implementation of injured hippocampus might depend mainly on the hypertrophy of contralateral hippocampus after HI brain injury. Corticosterone can partially prevent the hippocampal pyramidal cells from HI injury and reduce the difference of the bilateral hippocampus pyramidal cells, but there was no improvement in learning and memory.
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Región CA1 Hipocampal/patología , Dendritas/patología , Hipoxia-Isquemia Encefálica/patología , Células Piramidales/ultraestructura , Factores de Edad , Animales , Animales Recién Nacidos , Región CA1 Hipocampal/crecimiento & desarrollo , Corticosterona/farmacología , Corticosterona/uso terapéutico , Dendritas/efectos de los fármacos , Dendritas/ultraestructura , Modelos Animales de Enfermedad , Conducta Exploratoria , Lateralidad Funcional , Hipoxia-Isquemia Encefálica/tratamiento farmacológico , Hipoxia-Isquemia Encefálica/fisiopatología , Aprendizaje por Laberinto , Memoria , Células Piramidales/efectos de los fármacos , Células Piramidales/patología , Ratas , Ratas Sprague-Dawley , Tinción con Nitrato de Plata , Percepción EspacialRESUMEN
Chiglitazar sodium is a new peroxisome proliferator-activated receptor (PPAR) pan-agonist with independent intellectual property rights in China. It can treat type 2 diabetes mellitus and regulate metabolism by modestly activating PPARα, PPARγ, and PPARδ to improve insulin sensitivity, regulate blood glucose, and promote fatty acid oxidation and utilization. Chiglitazar sodium has a significant insulin-sensitizing effect and is advantageous in reducing fasting and postprandial blood glucose levels, particularly at the 48 mg dose in patients with concomitant high triglycerides in terms of blood glucose and triglyceride level control.
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PRIMARY OBJECTIVE: This study was designed to evaluate the effect of hypobaric hypoxia (HH) on the function and expression of P2X receptors in rat hippocampus CA1 pyramidal cells. RESEARCH DESIGN: The functional changes of P2X receptors were investigated through the cell HH model and the expressional alterations of P2X receptors were observed through the animal HH model. METHODS AND PROCEDURE: P2X receptors mediated currents were recorded from the freshly dissociated CA1 pyramidal cells of 7-day-old SD rats by whole cell patch clamp recording. The expression and distribution of P2X receptors were observed through immunohistochemistry and western blot at HH 3-day and 7-day. MAIN OUTCOMES AND RESULTS: In acute HH conditions, the amplitudes of ATP evoked peak currents were decreased compared to control. The immunohistochemistry and western blot results reflected there was no change in P2X receptors expression after 3 days HH injury, while P2X receptors expression was up-regulated in response to 7 days HH injury. CONCLUSIONS: These findings supported the possibility that the function of P2X receptors was sensitive to HH damage and long-term function decrease should result in the expression increase of P2X receptors.
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Región CA1 Hipocampal/metabolismo , Oxigenoterapia Hiperbárica , Hipoxia Encefálica/metabolismo , Células Piramidales/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Altitud , Animales , Velocidad del Flujo Sanguíneo , Región CA1 Hipocampal/irrigación sanguínea , Región CA1 Hipocampal/fisiopatología , Hipoxia Encefálica/fisiopatología , Inmunohistoquímica , Ratas , Ratas Sprague-DawleyRESUMEN
Background: It is reported that the incidence of language development disorder in children at the age of 2 is as high as 17.0%. Timely discovery of the high-risk factors of language development disorder in children and early intervention can greatly reduce the incidence of language development disorder and shorten the course and condition of the patients with language development disorder. Therefore, in order to facilitate prompt diagnosis and early interventions for children with language development disorder (DLD) and improve their language ability, this study explored the influence of perinatal factors on the language development of children in Ningxia and identified the unfavorable and favorable factors that influenced language development. Methods: Children diagnosed in the General Hospital of Ningxia Medical University during 2018-2021 who met the screening criteria for DLD and practical pediatric diagnostic criteria for DLD were enrolled in this study. Perinatal factors (gestational age, weight, sex, delivery mode, maternal age, presence of intrauterine infection, asphyxia) were retrospectively analyzed. The perinatal factors affecting language development were assessed using a one-way analysis of variance (ANOVA). Results: Among 1,500 children aged 0-3, 240 cases (16.00%) had language delay. Of these, 122 were male and 118 were female. There were 115 cases of comprehension and expression disorder, 30 cases of articulation disorder, and 90 cases of mixed manifestation. And there were 194 cases with definite intrauterine and perinatal high-risk factors or neonatal diseases, accounting for 80.83% of the total number of children with language delay. Conclusions: In Ningxia, factors in the neonatal period are the main cause of DLD, followed by fetal and maternal factors. Ischemic encephalopathy is the most common factor.
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Several studies have shown that astrocytes release neurotransmitters into the extracellular space that may then activate receptors on nearby neurons. In the present study, the actions of adenosine 5'-O-(2-thiodiphosphate) (ADPbetaS)-activated astrocyte conditioned medium (ADPbetaS-ACM) on cultured dorsal spinal cord neurons were evaluated by using confocal laser scanning microscopy and whole-cell patch-clamp recording. ADPbetaS caused astrocytic glutamate efflux (43 microM), which in turn induced inward currents in dorsal horn neurons with short time in culture. The inward currents were abolished by 2-amino-5-phosphonlanoicacid (AP-5; NMDAR antagonist) plus 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; non-NMDAR antagonist) but were unaffected by MRS2179 (selective P2Y(1) receptor antagonist). Furthermore, N6-methyl-2'-deoxyadenosine-3',5'-bisphosphate (MRS2179) was used to block glutamate release from astrocytes. As a result, ADPbetaS-ACM-induced inward currents in neurons were significantly blocked. On the other hand, both NMDAR and non-NMDAR were involved in ADPbetaS-ACM (concentration was diluted to one-tenth)-evoked small [Ca(2+)](i) transients in neurons. Under this condition, the values of glutamate concentrations in the medium are close to values for extracellular glutamate concentrations under physiological conditions. For this reason, it is possible that astrocyte-derived glutamate is important for distant neuron under physiological conditions at dorsal spinal cord. These observations indicate that astrocytic P2Y(1) receptor activation triggered glutamate efflux, which acts on distant neurons to elevate calcium levels or acts on nearby neurons to evoke inward current. Finally, our results support the conclusion that the astrocytic P2Y(1) receptor plays an important role in bidirectional communication between astrocytes and neurons.
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Astrocitos/metabolismo , Células del Asta Posterior/metabolismo , Receptores de Glutamato/metabolismo , Receptores Purinérgicos P2/metabolismo , Adenosina Difosfato/análogos & derivados , Adenosina Difosfato/farmacología , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , Comunicación Celular/efectos de los fármacos , Comunicación Celular/fisiología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Antagonistas de Aminoácidos Excitadores/farmacología , Líquido Extracelular/efectos de los fármacos , Líquido Extracelular/metabolismo , Ácido Glutámico/metabolismo , Microscopía Confocal , Técnicas de Placa-Clamp , Células del Asta Posterior/citología , Células del Asta Posterior/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de Glutamato/efectos de los fármacos , Receptores Purinérgicos P2/efectos de los fármacos , Receptores Purinérgicos P2Y1 , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Tionucleótidos/farmacologíaRESUMEN
D-serine is an important gliotransmitter in CNS. As an endogenous ligand for glycine-bind site in NR1 subunit of NMDA glutamate receptors, D-serine is more potent than glycine at activating the site. It is synthesized from L-serine via racemization of serine racemase, which is regulated by many factors. D-serine participates in many physiological and pathological progresses, including synaptic plasticity, sensory information transmission, neural development and neurotoxicity, and is supposed as potential therapeutic target for the treatment of nervous system disease like Alzheimer disease. Here, we provide an overview of recent findings on the mechanisms of its synthesis, degradation, release and physiological and pathological functions in CNS.
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Neuroglía/metabolismo , Neuronas/metabolismo , Serina/fisiología , Animales , Sistema Nervioso Central/fisiología , Humanos , Neuroglía/citología , Receptores de N-Metil-D-AspartatoRESUMEN
OBJECTIVE: To observe the effect of electroacupuncture (EA) on expression of hypothalamic sirtuin 1(SIRT1) and proopiomelanocortin (POMC), and body weight, food-intake, blood glucose, and blood lipid levels in obese rats, so as to explore its mechanisms underlying improvement of obesity. METHODS: Forty male Wistar rats were randomly divided into normal, model, EA, and sham EA groups (nï¼10 rats in each group). The obesity model was established by feeding the rats with high fat diet. EA (2 Hz, 1 mA) was applied to "Zusanli" (ST36), "Zhongwan" (CV12), "Guanyuan" (CV4) and "Fenglong" (ST40) or sham acupoints (about 5 mm beside each acupoint, shallow needling) for 20 min, once every other day for 8 weeks. The rats' body weight and food-intake were recorded. The blood glucose (fasting plasma glucose: FPG, postprandial plasma glucose: PPG) and blood lipids (triglyceride: TG, total cholesterol: TC, non esterified fatty acid: NEFA) were assayed by using an automatic biochemical analyzer. The protein and mRNA expression levels of SIRT1 and POMC in the hypothalamus were detected by Western blot and quantitative real-time PCR, respectively. RESULTS: In comparison with the normal group, the body weight, food-intake, blood lipids, and PPG levels were significantly increased (P<0.05ï¼P<0.01), and the expression levels of SIRT1 protein and mRNA in the hypothalamus were significantly doun-regulated in the model group (P<0.05). Following EA, the body weight, food-intake, blood lipids, and PPG levels were considerably down-regulated (P<0.01ï¼P<0.05), and the expression levels of SIRT1 and POMC protein and mRNA in the hypothalamus were significantly up-regulated in the EA group rather than those in the sham EA and the model groups (P<0.05)ï¼. CONCLUSION: EA can reduce the obese rats' body weight, food-intake, blood lipids and blood glucose, which may be associated with its effect in up-regulating the SIRT1 and POMC expression of hypothalamus.
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Electroacupuntura , Puntos de Acupuntura , Animales , Hipotálamo , Masculino , Obesidad , Proopiomelanocortina , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Sirtuina 1RESUMEN
It was reported that ATP, an excitatory chemical mediator, exerts its effects by activation of the P2X (ligand-gated cationic channels) and P2Y (G protein-coupled receptors) purinoceptors in the nervous system. In the present work, we used confocal laser scanning microscopy and high-performance liquid chromatography to assess the role of the P2Y1 receptor in ATP-evoked Ca2+ mobilization and glutamate release from cultured dorsal spinal cord astrocytes. ATP (0.01-100 micromol/l) produces a dose-dependent rise in the Ca2+ relative fluorescence intensity in cultured astrocytes. N6-methyl-2'-deoxyadenosine-3',5'-bisphosphate (MRS2179, 0.01-100 micromol/l), a P2Y1-specific antagonist, could dose-dependently inhibit ATP-evoked Ca2+ mobilization. In addition, 100 micromol/l ATP caused glutamate efflux from cultured dorsal spinal cord astrocytes in a time-dependent manner. 100 micromol/l MRS2179 significantly inhibited the glutamate efflux induced by ATP, which suggests that P2Y1 receptor activation is responsible for the ATP-induced glutamate efflux from astrocytes. Taken together, our results demonstrate that P2Y1 receptor plays an important role in modulating the function of astrocytes, which raises the possibility that MRS2179, a potent P2Y1-specific antagonist, may become a potential drug in treating many chronic neurological diseases characterized by astrocytic activation in the nervous system.
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Adenosina Difosfato/análogos & derivados , Adenosina Trifosfato/administración & dosificación , Astrocitos/metabolismo , Receptores Purinérgicos P2/metabolismo , Adenosina Difosfato/administración & dosificación , Adenosina Difosfato/farmacología , Adenosina Trifosfato/metabolismo , Animales , Astrocitos/efectos de los fármacos , Calcio/metabolismo , Células Cultivadas , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Ácido Glutámico/efectos de los fármacos , Ácido Glutámico/metabolismo , Microscopía Confocal , Células del Asta Posterior/efectos de los fármacos , Células del Asta Posterior/metabolismo , Antagonistas del Receptor Purinérgico P2 , Ratas , Ratas Sprague-Dawley , Receptores Purinérgicos P2Y1 , Factores de TiempoRESUMEN
Hypobaric hypoxia (HH) at high altitudes leads to a wide range of cognitive impairments which can handicap human normal activities and performances. However, the underlying mechanism is still unclear. Adenosine A2A receptors (A2ARs) of the brain are pivotal to synaptic plasticity and cognition. Besides, insult-induced up-regulation of A2AR regulates neuroinflammation and therefore induces brain damages in various neuropathological processes. The present study was designed to determine whether A2AR-mediate neuroinflammation involves in cognitive impairments under acute HH. A2AR knock-out and wild-type male mice were exposed to a simulated altitude of 8000â¯m for 7 consecutive days in a hypobaric chamber and simultaneously received behavioral tests including Morris water maze test and open filed test. A2AR expression, the activation of microglia and the production of TNF-α were evaluated in the hippocampus by immunohistochemistry and ELISA, respectively. Behavioral tests showed that acute HH exposure caused the dysfunction of spatial memory and mood, while genetic inactivation of A2AR attenuated the impairment of spatial memory but not that of mood. Double-labeled immunofluorescence showed that A2ARs were mainly expressed on microglia and up-regulated in the hippocampus of acute HH model mice. Acute HH also induced the accumulation of microglia and increased production of TNF-α in the hippocampus, which could be markedly inhibited by A2AR inactivation. These findings indicate that microglia-mediated neuroinflammation triggered by A2AR activation involves in acute HH-induced spatial memory impairment and that A2AR could be a new target for the pharmacotherapy of cognitive dysfunction at high altitudes.
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Altitud , Disfunción Cognitiva/metabolismo , Hipoxia/metabolismo , Inflamación/metabolismo , Microglía/metabolismo , Receptor de Adenosina A2A/metabolismo , Animales , Astrocitos/metabolismo , Astrocitos/patología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/patología , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Hipocampo/patología , Hipoxia/complicaciones , Hipoxia/patología , Hipoxia/psicología , Inflamación/complicaciones , Inflamación/patología , Inflamación/psicología , Masculino , Aprendizaje por Laberinto/fisiología , Ratones Endogámicos C57BL , Ratones Noqueados , Microglía/patología , Actividad Motora/fisiología , Neuroinmunomodulación/fisiología , Neuronas/metabolismo , Neuronas/patología , Receptor de Adenosina A2A/genética , Memoria Espacial/fisiología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Our previous studies have shown that recombinant human phospholipase D2 (rhPLD2) plays a modulator role on NF-κB and PKC signaling pathways. It also inhibits IL-5-induced inflammatory response in chronic asthmatic guinea pigs. Additionally, increasing evidence also has revealed that the adoptive transfer of induced regulatory T cells (Tregs) may be a therapeutic solution to airway allergic diseases. To investigate the epigenetic, transcriptomic and phenotypic variability of Treg population in an ovalbumin (OVA)-induced airway inflammation model derived from the induction of rhPLD2, OVA-induced asthmatic murine model is used in this study. The lung inflammation, eosinophil infiltration, the differentiation and proliferation of T helper cells and the amplification of Tregs were examined in this mouse model with and without rhPLD2 induction. Our data showed that rhPLD2 administration in asthmatic mice significantly increases CD4+CD25+ Foxp3+ Treg cell numbers and alleviates lung inflammation. The addition of rhPLD2 in vitro enhanced the demethylation of Treg-specificdemethylated region (TSDR) in iTregs, suggesting that rhPLD2 protein may be involved in improving the quality and quantity of Treg cells that eventually significantly reduces lung inflammation in asthmatic murine model. These results suggest that rhPLD2 could have a clinical impact treating patients with allergic airway inflammation via promoting and stabilizing iTreg differentiation and function.
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Asma/tratamiento farmacológico , Asma/inmunología , Factores de Transcripción Forkhead/metabolismo , Inflamación/tratamiento farmacológico , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Pulmón/patología , Fosfolipasa D/uso terapéutico , Linfocitos T Reguladores/inmunología , Traslado Adoptivo , Animales , Asma/patología , Islas de CpG/genética , Metilación de ADN/genética , Modelos Animales de Enfermedad , Eosinófilos/patología , Humanos , Ratones Endogámicos BALB C , Modelos Biológicos , Fosfolipasa D/farmacología , Estabilidad Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Linfocitos T Reguladores/efectos de los fármacosRESUMEN
Background: Transcranial direct current stimulation (tDCS) is widely used to treat human nerve disorders and neuropathic pain by modulating the excitability of cortex. The effectiveness of tDCS is influenced by its stimulation parameters, but there have been no systematic studies to help guide the selection of different parameters. Objective: This study aims to assess the effects of tDCS of primary motor cortex (M1) on chronic neuropathic pain in rats and to test for the optimal parameter combinations for analgesia. Methods: Using the chronic neuropathic pain models of chronic constriction injury (CCI), we measured pain thresholds before and after anodal-tDCS (A-tDCS) using different parameter conditions, including stimulation intensity, stimulation time, intervention time and electrode located (ipsilateral or contralateral M1 of the ligated paw on male/female CCI models). Results: Following the application of A-tDCS over M1, we observed that the antinociceptive effects were depended on different parameters. First, we found that repetitive A-tDCS had a longer analgesic effect than single stimulus, and both ipsilateral-tDCS (ip-tDCS) and contralateral-tDCS (con-tDCS) produce a long-lasting analgesic effect on neuropathic pain. Second, the antinociceptive effects were intensity-dependent and time-dependent, high intensities worked better than low intensities and long stimulus durations worked better than short stimulus durations. Third, timing of the intervention after injury affected the stimulation outcome, early use of tDCS was an effective method to prevent the development of pain, and more frequent intervention induced more analgesia in CCI rats, finally, similar antinociceptive effects of con- and ip-tDCS were observed in both sexes of CCI rats. Conclusion: Optimized protocols of tDCS for treating antinociceptive effects were developed. These findings should be taken into consideration when using tDCS to produce analgesic effects in clinical applications.
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Water intake reduction (anti-dipsogenic effects) under hypoxia has been well established, but the underlying reason remains unknown. Our previous report indicated that activated TRPV4 neurons in SFO are associated with anti-dipsogenic effects under hypoxia. Although low partial pressure of blood oxygen directly activates TRPV4, humoral factors could also be involved. In the present study, we hypothesize that adropin, a new endogenous peptide hormone, was rapidly increased (serum and brain) concomitant with reduced water intake in early hypoxia. Also, the nuclear expression of c-Fos, a marker for neuronal activation, related to water-consumption (SFO and MnPO) was inhibited. These effects were mitigated by a scavenger, rat adropin neutralizing antibody, which effectively neutralized adropin under hypoxia. Interestingly, injection of recombinant adropin in the third ventricle of the rats also triggered anti-dipsogenic effects and reduced c-Fos positive cells in SFO, but these effects were absent when TRPV4 was knocked down by shRNA. Moreover, adropin-activated CamKK-AMPK signaling related to TRPV4 calcium channel in SFO in normoxia. These results revealed that dissociative adropin was elevated in acute hypoxia, which was responsible for anti-dipsogenic effects by altering TRPV4-CamKK-AMPK signaling in SFO.
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The evolution of multiple myeloma (MM) depends on complex signals from the bone marrow microenvironment, which support proliferation and survival of malignant plasma cells. Previous study defined a brain-derived neurotrophic factor-tyrosine kinase receptor B (BDNF/TrkB) axis in myeloma and autocrine growth stimulation by BDNF in various tumor cells. We examined the biological effects of BDNF on MM cells. Using a reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry, we observed that both BDNF and its high-affinity receptor TrkB are expressed by MM cell lines (RPMI 8226, U266, and KM3) and primary MM cells. Functional studies revealed that BDNF was a potent growth factor for MM. BDNF (5-500 ng/mL) had strong proliferative effects on both MM cell lines and primary MM cells, shown by [(3)H]thymidine incorporation assay. BDNF (12.5-200 ng/mL) also induced migration of MM cells, as indicated by the Transwell migration assay. Together, our data indicate that BDNF is a potent myeloma growth and chemotactic factor and suggest that the BDNF/TrkB pathway is a potential therapeutic target in MM.
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Factor Neurotrófico Derivado del Encéfalo/farmacología , División Celular/efectos de los fármacos , Mieloma Múltiple/patología , Secuencia de Bases , Western Blotting , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cartilla de ADN , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunohistoquímica , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Recent studies have proved that brain-derived neurotrophic factor (BDNF) possesses angiogenic activity in vitro and in vivo. However, the proangiogenic mechanism of BDNF has not yet been provided with enough information. To explore the proangiogenic mechanism of BDNF, we investigated the effects of BDNF on extracellular proteolytic enzymes, including matrix metalloproteinases (MMPs) and serine proteases, particularly the urokinase-type plasminogen activator (uPA)-plasmin system in human umbilical vein endothelial cells (HUVECs) model. METHODS: Tube formation assay was performed in vitro to evaluate the effects of BDNF on angiogenesis. The HUVECs were treated with various concentrations of BDNF (25 - 400 ng/ml) for different (6 - 48 hours), reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assay MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNA in HUVECs, and the conditioned medium was analyzed for MMP and uPA activity by gelatin zymography and fibrin zymography, respectively. uPA, plasminogen activator inhibitor (PAI)-1, tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-2 were quantified by western blotting analysis. RESULTS: BDNF elicited robust and elongated angiogeneis in two-dimensional cultures of HUVECs in comparison with control. The stimulation of serum-starved HUVECs with BDNF caused obvious increase in MMP-2 and MMP-9 mRNA expression and induced the pro-MMP-2 and pro-MMP-9 activation without significant differences in proliferation. However, BDNF had no effect on TIMP-1 and TIMP-2 production. BDNF increased uPA and PAI-1 production in a dose-dependent manner. Maximal activation of uPA and PAI-1 expression in HUVECs was induced by 100 ng/ml BDNF, while effects of 200 ng/ml and 400 ng/ml BDNF were slightly reduced in comparison with with those of 100 ng/ml. Protease activity for uPA was also increased by BDNF in a dose-dependent manner. BDNF also stimulated uPA and PAI-1 production beyond that in control cultures in a time-dependent manner from 12 hours to 48 hours after BDNF treatment. CONCLUSIONS: BDNF stimulates MMP and uPA/PAI-1 proteolytic network in HUVECs, which may be important to the acquisition of proangiogenic potential.
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Factor Neurotrófico Derivado del Encéfalo/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Neovascularización Fisiológica/efectos de los fármacos , Células Cultivadas , Humanos , Inhibidor 1 de Activador Plasminogénico/genética , ARN Mensajero/análisis , Activador de Plasminógeno de Tipo Uroquinasa/genéticaRESUMEN
OBJECTIVE: To investigate the expression of brain-derived neurotrophic factor (BDNF) and its receptors in multiple myeloma (MM) cells and the biological effects of BDNF on MM cells. METHODS: Transcription and protein expression of BDNF and its receptors (TrkB and P75(NTR)) in human myeloma cell lines (HMCLs) was determined with RT-PCR and Western blotting. BDNF levels in culture supernatant was determined with enzyme-linked immunosorbent assay. The expression of BDNF and TrkB by myeloma cells was studied with immunohistochemistry in bone marrow biopsy samples from 15 patients with MM. The effect of BDNF on the in vitro proliferation of HMCLs (RPMI 8226, U266, KM3) was examined with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The effect of BDNF on HMCLs migration was studied with modified Boyden chamber assay. RESULTS: BDNF was expressed and secreted by HMCLs in high concentrations up to 14.7 microg/L. Furthermore, expression of its high affinity receptor TrkB was observed in HMCLs. BDNF expression by myeloma cells was demonstrated in 12 of the 15 patients with MM (80%), TrkB expression was demonstrated in all the 15 patients (100%), whereas control bone marrow samples showed weaker expression of BDNF in 2 of 9 (22.2%) and TrkB in 4 of 9 (44.4%). Functional studies demonstrated that BDNF has strong proliferative effects on HMCLs and proliferation of RPMI 8226 was enhanced by BDNF in a time- and dose-dependent manner. Moreover, BDNF has chemotactic properties on HMCLs. The maximal responses were seen at 50 microg/L for RPMI 8266 (P < 0.05) and 25 microg/L for KM3 cells (P < 0.01) as compared with nonstimulated controls. CONCLUSION: BDNF and its high affinity receptor TrkB are co-expressed by MM cells. BDNF appears to have a major contribution to the pathophysiology of MM leading to proliferation and migration of MM cells. These provide the framework for novel therapeutic strategies targeting BDNF/TrkB signaling in MM.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/farmacología , Proliferación Celular/efectos de los fármacos , Mieloma Múltiple/metabolismo , Receptor trkB/metabolismo , Adolescente , Adulto , Anciano , Factor Neurotrófico Derivado del Encéfalo/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Persona de Mediana Edad , Mieloma Múltiple/patología , ARN Mensajero/genética , Receptor trkB/genéticaRESUMEN
Peripheral and spinal hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play a key role in neuropathic pain by regulating neuronal excitability. HCN channels are expressed in the ventral-lateral periaqueductal gray (vlPAG), a region that is important for pain modulation. However, the role of vlPAG HCN channels in neuropathic pain remains poorly understood. In the present study, we investigated the impact of changes to vlPAG HCN channels on neural activity in neuropathic pain. First, sciatic nerve chronic constriction injury (CCI) was established as a neuropathic pain model. Then, changes in HCN channels and their influence on vlPAG neuronal activity were detected. Our results indicate that after CCI surgery the following changes occur in vlPAG neurons: the expression of HCN1 and HCN2 channels is increased, the amplitude of the hyperpolarization-activated current (Ih) is augmented and its activation curve is shifted to more positive potentials and there is an increase in the frequency of action potential (AP) firing and spontaneous EPSCs that is attenuated by ZD7288, a HCN channel blocker. In addition, forskolin, which can elevate intracellular cAMP, mimics the CCI induced changes in neuronal excitability in the vlPAG. The effects of forskolin were also reversed by ZD7288. Taken together, the present data indicate an important role for HCN channels in the vlPAG in neuropathic pain.
Asunto(s)
Canales Catiónicos Regulados por Nucleótidos Cíclicos/metabolismo , Neuralgia/metabolismo , Neuronas/metabolismo , Sustancia Gris Periacueductal/metabolismo , Neuropatía Ciática/metabolismo , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Canales Catiónicos Regulados por Nucleótidos Cíclicos/antagonistas & inhibidores , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/fisiología , Neuralgia/fisiopatología , Neuronas/efectos de los fármacos , Técnicas de Placa-Clamp , Sustancia Gris Periacueductal/efectos de los fármacos , Sustancia Gris Periacueductal/fisiopatología , Pirimidinas/farmacología , Ratas , Ratas Sprague-Dawley , Neuropatía Ciática/fisiopatologíaRESUMEN
Peripheral and spinal hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels play important roles in neuropathic pain by regulating neuronal excitability. However, the participation of HCN channels in the ventral-lateral periaqueductal gray (vlPAG) during neuropathic pain states has not been clarified. To investigate the role of vlPAG HCN channels in neuropathic pain, the authors developed a chronic constriction injury (CCI) model. By using western blot analysis, they detected the upregulation of HCN1 and HCN2 channel expression at vlPAG 14 days post-CCI surgery. Subsequently, the function of these upregulated channels was verified by the intravlPAG infusion of ZD7288, a specific HCN blocker, which significantly relieved mechanical allodynia and thermal hyperalgesia in CCI animals. These results suggest that the upregulation of vlPAG HCN channels plays an important role in pain maintenance and might be a target for attenuating pain.