RESUMO
The objective of this investigation was to examine the impact of multiple exposures to general anesthesia (GA) with sevoflurane on the offspring of pregnant mice, as well as to elucidate the underlying mechanism. Neurodevelopmental assessments, including various reflexes and behavioral tests, were conducted on the offspring in the GA group to evaluate neuronal cell development. Furthermore, neonatal mouse neuronal cells were isolated and transfected with a high-expression CREB vector (pcDNA3.1-CREB), followed by treatment with sevoflurane (0.72 mol/L), ZD7288 (50 µmol/L), and KN-62 (10 µmol/L), or a combination of these compounds. The expression of relevant genes was then analyzed using qRT-PCR and western blot techniques. In comparison to the sham group, neonatal mice in the GA group exhibited significantly prolonged latencies in surface righting reflex, geotaxis test, and air righting reflex. Furthermore, there was a notable deceleration in the development of body weight and tail in the GA group. These mice also displayed impairments in social ability, reduced reciprocal social interaction behaviors, diminished learning capacity, and heightened levels of anxious behaviors. Additionally, synaptic trigger malfunction was observed, along with decreased production of c-Fos and neurotrophic factors. Sevoflurane was found to notably decrease cellular c-Fos and neurotrophic factor production, as well as the expression of HCN2 and CaMKII/CREB-related proteins. The inhibitory effects of sevoflurane on HCN2 or CaMKII channels were similar to those observed with ZD7288 or KN-62 inhibition. However, overexpression of CREB mitigated the impact of sevoflurane on neuronal cells. Repetitive exposure to sevoflurane general anesthesia while pregnant suppresses the CaMKII/CREB pathway, leading to the development of autism-like characteristics in offspring mice through the reduction of HCN2 expression.
Assuntos
Anestésicos Inalatórios , Transtorno Autístico , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Regulação para Baixo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Efeitos Tardios da Exposição Pré-Natal , Sevoflurano , Animais , Sevoflurano/farmacologia , Sevoflurano/toxicidade , Camundongos , Gravidez , Feminino , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Anestésicos Inalatórios/farmacologia , Anestésicos Inalatórios/toxicidade , Anestésicos Inalatórios/efeitos adversos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Transtorno Autístico/genética , Transtorno Autístico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Canais de Potássio/metabolismo , Canais de Potássio/genética , Células Cultivadas , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BLRESUMO
Postoperative cognitive dysfunction (POCD), a neurological complication after surgery, is common among the elderly in particular. Maternal expression gene 3 (MEG3) is a novel long non-coding RNA (lncRNA) that contributes to glial cell activation and inflammation. We aim to further explore its role in POCD. Mice were induced with sevoflurane anesthesia and underwent orthopedic surgery to establish a POCD model. BV-2 microglia activation was induced by lipopolysaccharide. The overexpressed lentiviral plasmid lv-MEG3 and its control were injected into mice. pcDNA3.1-MEG3, has-miR-106a-5p mimic, and its negative control were transfected into BV-2 cells. The expressions of has-miR-106a-5p MEG3 and Sirtuin 3 (SIRT3) in rat hippocampus and BV-2 cells were quantitatively detected. Levels of SIRT3, TNF-α, and IL-1ß were detected by western blot, levels of TNF-α and IL-1ß by ELISA, and expression of GSH-Px, SOD, and MDA by kits. The targeting relationship between MEG3 and has-miR-106a-5p was confirmed using bioinformatics and dual-luciferase reporter assay. LncRNA MEG3 was down-regulated in POCD mice, whereas has-miR-106a-5 levels were up-regulated. Overexpression of MEG3 could attenuate cognitive dysfunction and inflammatory response in POCD mice, inhibit lipopolysaccharide-induced inflammatory response and oxidative stress in BV-2 cells, and promote has-miR-106a through competitive binding with has-miR-106a-5-5 expression of target gene SIRT3. Overexpression of has-miR-106a-5p had a reverse effect on overexpression of MEG3 functioning on lipopolysaccharide-induced BV-2 cells. LncRNA MEG3 could inhibit the inflammatory response and oxidative stress via has-miR-106a-5p/SIRT3, thereby reducing POCD, which might be a potential biological target for the diagnosis and treatment of clinical POCD.
Assuntos
MicroRNAs , Complicações Cognitivas Pós-Operatórias , RNA Longo não Codificante , Sirtuína 3 , Animais , Camundongos , Linhagem Celular Tumoral , Lipopolissacarídeos/toxicidade , MicroRNAs/metabolismo , Estresse Oxidativo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Chronic cerebral hypoperfusion (CCH) is a main mechanism of cerebrovascular disease and is associated with various cerebrovascular and neurodegenerative diseases, including Alzheimer's disease. However, treatment of CCH in clinical practice is not ideal, but neurotropin (NTP) has been shown to have a neuroprotective effect. Therefore, this study examined the effect and possible mechanism of NTP in nerve injury caused by CCH. A rat CCH model was established by bilateral common carotid artery occlusion (2VO), and rats were treated with intragastric administration of NTP (200 nu/kg/day) for 28 consecutive days. After treatment, rats were subjected to the Morris water maze and novel object recognition test. Subsequently, an ELISA was applied to detect amyloid-ß (Aß) 1-40 and Aß1-42 levels in rat hippocampal tissues, quantitative reverse transcription PCR assays were used to detect the mRNA expression levels of brain-derived neurotrophic factor (BDNF) and Trk B, and Western blots were used to detect the protein expression levels of BACE1, tau, p-tau, and protein kinase B (Akt)/glycogen synthase kinase 3ß (GSK3ß) pathway-related proteins. The rat model of CCH was successfully established by 2VO. Behavioral tests indicated that the cognitive ability of 2VO rats was severely impaired. NTP treatment greatly ameliorated the cognitive disability, reduced Aß1-40 and Aß1-42 levels and tau phosphorylation, and upregulated BACE1, Trk B, and BDNF expression in the hippocampus of 2VO rats. Finally, we found that NTP markedly activated Akt/GSK3ß pathway activity. NTP can ameliorate cognitive disability in CCH rats possibly by reducing Aß accumulation and tau phosphorylation in the hippocampus. These effects of NTP may be related to the Akt/GSK3ß pathway activation. NTP may be a promising new drug candidate for CCH patients.
Assuntos
Doença de Alzheimer , Isquemia Encefálica , Ratos , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Cognição , Peptídeos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Aprendizagem em LabirintoRESUMO
[This corrects the article DOI: 10.1093/toxres/tfab047.].
RESUMO
This study aimed to clarify the mechanism of propofol on proliferation and apoptosis of colorectal cancer (CRC) cell. SW620 and HCT15 cells were exposed to different concentrations of propofol, the proliferation and apoptotic rate, were measured by MTT, colony formation and flow cytometry assays, respectively. The expressions of miR-1-3p and insulin-like growth factors 1 (IGF1) were examined by real-time polymerase chain reaction (RT-qPCR). Western bolt was employed to quantify the protein levels of IGF1 and apoptotic proteins. The molecular interaction between miR-1-3p and IGF1 was validated using dual-luciferase reporter assay. A xenograft tumor model was established to further assess the effects of propofol on CRC in vivo. Propofol dramatically decreased the proliferation and elevated apoptotic rate of CRC cells. RT-qPCR assay demonstrated that miR-1-3p was downregulated in CRC cells, and could be strikingly increased by propofol. Importantly, miR-1-3p inhibited IGF-1 expression through interacting with its 3'-UTR region, thus inactivating AKT/mTOR signals. Gain or loss of functional study revealed that miR-1-3p downregulation remarkedly diminished the anti-tumor roles of propofol by directly inhibiting IGF1. In vivo study showed that propofol inhibited tumor growth by regulating miR-1-3p/IGF1 axis. Our data eventually elucidated that propofol suppressed CRC progression by promoting miR-1-3p which targeted IGF1. These results might provide a scientific basis for the application of propofol on the clinical surgery and the prognosis of patients with CRC.
RESUMO
Cav3 channels play an important role in modulating chronic pain. However, less is known about the functional changes of Cav3 channels in superficial spinal dorsal horn in neuropathic pain states. Here, we examined the effect of partial sciatic nerve ligation (PSNL) on either expression or electrophysiological properties of Cav3 channels in superficial spinal dorsal horn. Our in vivo studies showed that the blockers of Cav3 channels robustly alleviated PSNL-induced mechanical allodynia and thermal hyperalgesia, which lasted at least 14 days following PSNL. Meanwhile, PSNL triggered an increase in both mRNA and protein levels of Cav3.2 but not Cav3.1 or Cav3.3 in rats. However, in Cav3.2 knockout mice, PSNL predominantly attenuated mechanical allodynia but not thermal hyperalgesia. In addition, the results of whole-cell patch-clamp recordings showed that both the overall proportion of Cav3 current-expressing neurons and the Cav3 current density in individual neurons were elevated in spinal lamina II neurons from PSNL rats, which could not be recapitulated in Cav3.2 knockout mice. Altogether, our findings reveal that the elevated functional Cav3.2 channels in superficial spinal dorsal horn may contribute to the mechanical allodynia in PSNL-induced neuropathic pain model.
Assuntos
Canais de Cálcio Tipo T/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Animais , Western Blotting , Canais de Cálcio Tipo T/genética , Eletrofisiologia , Hiperalgesia/genética , Hiperalgesia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Substância Gelatinosa/citologiaRESUMO
Spinal lamina II (substantia gelatinosa, SG) neurons integrate nociceptive information from the primary afferents and are classified according to electrophysiological (tonic firing, delayed firing, single spike, initial burst, phasic firing, gap firing and reluctant firing) or morphological (islet, central, vertical, radial and unclassified) criteria. T-type calcium (Cav3) channels play an essential role in the central mechanism of pathological pain, but the electrophysiological properties and the cell-type specific distribution of T-type channels in SG neurons have not been fully elucidated. To investigate the electrophysiological and morphological features of T-type channel-expressing or -lacking neurons, voltage- and current-clamp recordings were performed on either transverse or parasagittal spinal cord slices. Recording made in transverse spinal cord slices showed that an inward current (I T) was observed in 44.5% of the SG neurons that was fully blocked by Ni2+ and TTA-A2. The amplitude of I T depended on the magnitude and the duration of hyperpolarization pre-pulse. The voltage for eliciting and maximizing I T were -70 mV and -35 mV, respectively. In addition, we found that most of the I T-expressing neurons are tonic firing neurons and exhibit more negative action potential (AP) threshold and smaller difference of AP threshold and resting membrane potential (RMP) than those neurons lacking I T. Consistently, a specific T-type calcium channel blocker TTA-P2 increased the AP threshold and enlarged the difference between AP threshold and membrane potential (Ihold = 0). Meanwhile, the morphological analysis indicated that most of the I T-expressing neurons are islet neurons. In conclusion, we identify a cell-type specific distribution and the function of T-type channels in SG neurons. These findings might provide new insights into the mechanisms underlying the contribution of T-type channels in sensory transmission.
RESUMO
Objective: Oxytocin (OT) is synthesized within the paraventricular nucleus and supraoptic nucleus of the hypothalamus. In addition to its role in uterine contraction, OT plays an important antinociceptive role; however, the underlying molecular mechanisms of antinociceptive role of OT remain elusive. We hypothesized that the antinociceptive effect of OT on neuropathic pain may occur via inhibition of TRPV1 activation in the spinal cord. The present study explores the antinociceptive role of OT and its mechanisms in neuropathic pain. Methods: Partial sciatic nerve ligation (pSNL) was performed to induce neuropathic pain. Animal behaviors were measured using a set of electronic von Frey apparatus and hot plate. Electrophysiological recordings and molecular biological experiments were performed. Results: Intrathecal administration of OT alleviated both mechanical allodynia and thermal hyperalgesia in pSNL rats (n = 6, per group, P < 0.0001, saline vs. OT group). Electrophysiological data revealed that OT significantly inhibited the enhancement of frequency and amplitude of spontaneous excitatory post-synaptic currents induced presynaptically by TRPV1 activation in the spinal cord. Moreover, the inhibitory effect of OT on capsaicin-induced facilitation of excitatory transmission was blocked by co-treatment with saclofen, while intrathecal administration of OT dramatically inhibited capsaicin-induced ongoing pain in rats, (n = 6, per group, P < 0.0001, saline vs. OT group). The paw withdrawal latency in response to heat stimulation was significantly impaired in TRPV1KO mice 3 days after pSNL upon OT (i.t.) treatment, compared with wild type mice (n = 6, P < 0.05). Finally, OT prevented TRPV1 up-regulation in spinal cords of pSNL model rats. Conclusion: OT relieves neuropathic pain through GABA release and presynaptic TRPV1 inhibition in the spinal cord. OT and its receptor system might be an intriguing target for the treatment and prevention of neuropathic pain.