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Introduction: The mechanisms leading to ovarian primordial follicle depletion following gonadotoxic chemotherapy with cyclophosphamide and other cytotoxic drugs are currently understood through two main explanatory theories: apoptosis and over-activation. Discrepancies between the findings of different studies investigating these mechanisms do not allow to reach a firm conclusion. The heterogeneity of cell types in ovaries and their different degrees of sensitivity to damage, cell-cell interactions, periodical follicle profile differences, model age-dependent differences, and differences of exposure durations of tested drugs may partially explain the discrepancies among studies. Methods: This study used intact prepubertal mice ovaries in culture as study model, in which most follicles are primordial follicles. Histological and transcriptional analyses of ovaries exposed to the active metabolite of cyclophosphamide 4-hydroperoxycyclophosphamide (4-HC) were carried out via a time-course experiment at 8, 24, 48, and 72 h. Results: 4-HC treated ovaries showed a significant decrease in primordial follicle density at 24 h, along with active DNA damage (TUNEL) and overexpressed apoptosis signals (cleaved-poly ADP ribose polymerase in immunohistochemistry and western blotting). Meanwhile 4-HC treatment significantly up-regulated H2ax, Casp 6, Casp 8, Noxa, and Bax in ovaries, and up-regulated Puma in primordial follicles (FISH). Discussion: Our results indicated that cyclophosphamide-induced acute ovarian primordial follicle depletion was mainly related to apoptotic pathways. No evidence of follicle activation was found, neither through changes in the expression of related genes to follicle activation nor in the density of growing follicles. Further validation at protein level in 4-HC-treated prepubertal mice ovaries at 24 h confirmed these observations.
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Apoptosis , Ciclofosfamida , Folículo Ovárico , Animales , Ciclofosfamida/farmacología , Ciclofosfamida/toxicidad , Ciclofosfamida/efectos adversos , Femenino , Apoptosis/efectos de los fármacos , Ratones , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/metabolismo , Antineoplásicos Alquilantes/farmacología , Antineoplásicos Alquilantes/toxicidad , Antineoplásicos Alquilantes/efectos adversos , Daño del ADN/efectos de los fármacos , Maduración Sexual/efectos de los fármacosRESUMEN
Background: Severe burns can lead to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) due to inflammation-immunity dysregulation. This study aimed to identify key immune-related molecules and potential drugs for immune regulation in severe burn treatment. Method: Microarray datasets GSE77791 and GSE37069 were analyzed to identify immune-related differentially expressed genes (DEGs), enriched pathways and prognosis-related genes. The DGIdb database was used to identify potentially clinically relevant small molecular drugs for hub DEGs. Hub DEGs were validated by total RNA from clinical blood samples through qPCR. The efficacy of drug candidates was tested in a severe burn mouse model. Pathologic staining was used to observe organ damage. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect the serum IL-1b, IL-6, TNF-a and MCP-1 contents. Activation of the NF-κB inflammatory pathway was detected by western blotting. Transcriptome sequencing was used to observe inflammatory-immune responses in the lung. Results: A total of 113 immune-related DEGs were identified, and the presence of immune overactivation was confirmed in severe burns. S100A8 was not only significantly upregulated and identified to be prognosis-related among the hub DEGs but also exhibited an increasing trend in clinical blood samples. Methotrexate, which targets S100A8, as predicted by the DGIdb, significantly reduces transcription level of S100A8 and inflammatory cytokine content in blood, organ damage (lungs, liver, spleen, and kidneys) and mortality in severely burned mice when combined with fluid resuscitation. The inflammatory-immune response was suppressed in the lungs. Conclusion: S100A8 with high transcription level in blood is a potential biomarker for poor severe burn prognosis. It suggested that methotrexate has a potential application in severe burn immunotherapy. Besides, it should be emphasized that fluid resuscitation is necessary for the function of methotrexate.
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Quemaduras , Quemaduras/inmunología , Animales , Ratones , Humanos , Pronóstico , Masculino , Perfilación de la Expresión Génica , Modelos Animales de Enfermedad , Metotrexato/uso terapéutico , Citocinas/metabolismo , Citocinas/sangre , Biología Computacional/métodos , Transcriptoma , Ratones Endogámicos C57BL , Femenino , BiomarcadoresRESUMEN
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The overactivation of ß-adrenergic receptors (ß-ARs) can result in acute myocardial ischemic injury, culminating in myocardial necrosis. Berberine (BBR) has exhibited promising potential for prevention and treatment in various heart diseases. However, its specific role in mitigating myocardial injury induced by acute ß-AR overactivation remains unexplored. This study aimed to investigate the effects and underlying mechanisms of BBR pretreatment in a rat model of acute ß-AR overactivation induced by a single dose of the nonselective ß-adrenergic agonist isoprenaline (ISO). Rats were pretreated with saline or BBR (100 mg/kg/day) via gavage for 14 consecutive days, followed by a subcutaneous injection of ISO or saline on the 14th day. The findings indicated that BBR pretreatment significantly attenuated myocardial injury in ISO-stimulated rats, as evidenced by reduced pathological inflammatory infiltration, necrosis, and serum markers of myocardial damage. Additionally, BBR decreased oxidative stress and inflammation in the system and heart. Furthermore, BBR pretreatment enhanced myocardial ATP levels, improved mitochondrial dysfunction through increased Drp1 phosphorylation, and augmented myocardial autophagy. In a CoCl2-induced H9c2 cell hypoxic injury model, BBR pretreatment mitigated cellular injury, apoptosis, and oxidative stress while upregulating Drp1 and autophagy-associated proteins. Mechanistically, BBR pretreatment activated AKT, AMPK, and LKB1 both in vivo and in vitro, implicating the involvement of the AKT and LKB1/AMPK signaling pathways in its cardioprotective effects. Our study demonstrated the protective effects of BBR against myocardial injury induced by acute ß-AR overactivation in rats, highlighting the potential of BBR as a preventive agent for myocardial injury associated with ß-adrenergic overactivation.
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Agonistas Adrenérgicos beta , Berberina , Isoproterenol , Ratas Sprague-Dawley , Animales , Berberina/farmacología , Masculino , Ratas , Isoproterenol/toxicidad , Agonistas Adrenérgicos beta/toxicidad , Estrés Oxidativo/efectos de los fármacos , Receptores Adrenérgicos beta/metabolismo , Receptores Adrenérgicos beta/efectos de los fármacos , Miocardio/patología , Miocardio/metabolismo , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Miocitos Cardíacos/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
This scoping review prepared by endocrinology and nephrology experts aimed to address the significance of finerenone, as a novel therapeutic option, in diabetic kidney disease (DKD), based on the biological prospect of cardiorenal benefit due to non-steroidal mineralocorticoid receptor antagonist (MRA) properties, and the recent evidence from the finerenone phase 3 program clinical trials. The importance of finerenone in slowing DKD progression was critically reviewed in relation to the role of MR overactivation in the pathogenesis of cardiorenal disease and unmet needs in the current practice patterns. The efficacy and safety outcomes of finerenone phase III study program including FIDELIO-DKD, FIGARO-DKD and FIDELITY were presented. Specifically, perspectives on inclusion of patients with preserved estimated glomerular filtration rate (eGFR) or high albuminuria, concomitant use of sodium-glucose co-transporter-2 inhibitor (SGLT2i) or glucagon-like peptide 1 receptor agonist (GLP-1 RA), baseline glycated hemoglobin (HbA1c) level and insulin treatment, clinically meaningful heart failure outcomes and treatment-induced hyperkalemia were addressed. Finerenone has emerged as a new therapeutic agent that slows DKD progression, reduces albuminuria and risk of cardiovascular complications, regardless of the baseline HbA1c levels and concomitant treatments (SGLT2i, GLP-1 RA, or insulin) and with a favorable benefit-risk profile. The evolving data on the benefit of SGLT2is and non-steroidal MRAs in slowing or reducing cardiorenal risk seem to provide the opportunity to use these pillars of therapy in the management of DKD, after a long-period of treatment scarcity in this field. Along with recognition of the albuminuria as a powerful marker to detect those patients at high risk of cardiorenal disease, these important developments would likely to impact standard-of-care options in the setting of DKD.
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Heart failure with preserved ejection fraction (HFpEF) is a multifaceted pathogenesis disease and the exact mechanisms driving HFpEF have not been completely elucidated. Pressure overload hypertrophy (POH) related fibroblasts and M2 macrophages in HFpEF myocardium have been recently identified and are now of great interest. Sympathetic overdrive has also been implicated in HFpEF. This study is designed to dynamically observe the potential roles of aforementioned mechanisms in pathological remodeling and cardiac dysfunction in chronic PO rats. Surgical constriction of the abdominal aorta was used for induction of HFpEF. Echocardiography, electrocardiogram, hemodynamic measurement, hematoxylin and eosin staining, Masson staining, immunohistochemistry and immunofluorescence were performed to assess the changes in heart dysfunction, cardiac remodeling and driving mechanisms at different time points (2, 18, 24 weeks). The PO induced HFpEF model was well established, which was confirmed by the persistent increase in carotid artery systolic and diastolic blood pressure, and left ventricle hypertrophy at the corresponding postoperative stage. Meanwhile, PO hypertrophy gradually developed into HFpEF, associated with QT and QTc intervals prolongation, normal systolic (EF was maintained at >50%) but impaired diastolic function (increasing LVEDP and LV -dP/dtmin, abnormal E/A ratio), increased myocytes size, and observed relatively slight inflammatory infiltration but robust reactive fibrosis. IHC staining further confirmed that macrophages (CD68) but not neutrophils (MPO) or T cells (CD3) accounted for a predominant proportion of infiltrating cells. Mechanistically, we found that the infiltrating macrophages in the heart expressed high levels of CD206 which was simultaneously adjacent to POH fibroblasts appeared to overexpression of α-SMA in PO rats at late stages. Interestingly, we distinguished two different POHF sub-populations during PO induced HFpEF development, according to non overlapping signals of α-SMA and PDGFRα/ß proteins. Additionally, PO led to a pronounced exaggeration in sympathetic fibers at all time points. These findings suggest that the establishing model here begins with cardiac sympathetic overdrive, subsequently along with immune cells especially M2 macrophage accumulation and fibroblast heterogeneity at later stages is associated with the development of cardiac maladaptive remodeling and diastolic dysfunction thus further progression to HFpEF.
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Epidemiological studies show that cardiovascular events related to platelet hyperactivity remain the leading causes of death among multiple sclerosis (MS) patients. Quantitative or structural changes of platelet cytoskeleton alter their morphology and function. Here, we demonstrated, for the first time, the structural changes in MS platelets that may be related to their hyperactivity. MS platelets were found to form large aggregates compared to control platelets. In contrast to the control, the images of overactivated, irregularly shaped MS platelets show changes in the cytoskeleton architecture, fragmented microtubule rings. Furthermore, MS platelets have long and numerous pseudopodia rich in actin filaments. We showed that MS platelets and megakaryocytes, overexpress ß1-tubulin and ß-actin mRNAs and proteins and have altered post-translational modification patterns. Moreover, we identified two previously undisclosed mutations in the gene encoding ß1-tubulin in MS. We propose that the demonstrated structural changes of platelet cytoskeleton enhance their ability to adhere, aggregate, and degranulate fueling the risk of adverse cardiovascular events in MS.
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Plaquetas , Proteínas del Citoesqueleto , Citoesqueleto , Esclerosis Múltiple , Tubulina (Proteína) , Humanos , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/patología , Esclerosis Múltiple/sangre , Plaquetas/metabolismo , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/genética , Femenino , Citoesqueleto/metabolismo , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Adulto , Masculino , Persona de Mediana Edad , Actinas/metabolismo , Actinas/genética , Megacariocitos/metabolismo , Megacariocitos/patología , Procesamiento Proteico-Postraduccional , MutaciónRESUMEN
Postoperative cognitive dysfunction (POCD) is a common complication following surgery, adversely impacting patients' recovery, increasing the risk of negative outcomes, prolonged hospitalization, and higher mortality rates. The N-methyl-D-aspartate (NMDA) receptor, crucial for learning, memory, and synaptic plasticity, plays a significant role in the development of POCD. Various perioperative factors, including age and anesthetic use, can reduce NMDA receptor function, while surgical stress, inflammation, and pain may lead to its excessive activation. This review consolidates preclinical and clinical research to explore the intricate relationship between perioperative factors affecting NMDA receptor functionality and the onset of POCD. It discusses the influence of aging, anesthetic administration, perioperative injury, pain, and inflammation on the NMDA receptor-related pathophysiology of POCD. The comprehensive analysis presented aims to identify effective treatment targets for POCD, contributing to the improvement of patient outcomes post-surgery.
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Anestésicos , Disfunción Cognitiva , Complicaciones Cognitivas Postoperatorias , Humanos , Complicaciones Cognitivas Postoperatorias/etiología , Receptores de N-Metil-D-Aspartato , Dolor/complicaciones , Inflamación/complicaciones , Complicaciones Posoperatorias/etiología , Disfunción Cognitiva/complicacionesRESUMEN
Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.
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Miocarditis , Miocarditis/diagnóstico , Miocarditis/terapia , Humanos , China , Adulto , Cardiología/métodos , Cardiología/normas , Pronóstico , Sociedades MédicasRESUMEN
Excessive neuroinflammation mediated by microglia has a detrimental effect on the progression of ischemic stroke. Eriocalyxin B (EriB) was found with a neuroprotective effect in mice with Parkinson's disease via the suppression of microglial overactivation. This study aimed to investigate the roles of EriB in permanent middle cerebral artery occlusion (pMCAO) mice. The pMCAO was induced in the internal carotid artery of the mice by the intraluminal filament method, and EriB (10 mg/kg) was administered immediately after surgery by intraperitoneal injection. The behavior score, 2,3,5-triphenyltetrazole chloride staining, Nissl staining, TUNEL, immunohistochemistry, immunofluorescence, PCR, ELISA, and immunoblotting revealed that EriB administration reduced brain infarct and neuron death and ameliorated neuroinflammation and microglia overactivation in pMCAO mice, manifested by alterations of TUNEL-positive cell numbers, ionized calcium binding adaptor molecule 1 (Iba-1)-positive cell numbers, and expression of tumor necrosis factor-α, interleukin 6, IL-1ß, inducible nitric oxide synthase, and arginase 1. In addition, EriB suppressed ischemia-induced activation of nuclear factor kappa B (NF-κB) signaling in the brain penumbra, suggesting the involvement of NF-κB in EriB function. In conclusion, EriB exerted anti-inflammatory effects in ischemia stroke by regulating the NF-κB signaling pathway, and this may provide insights into the neuroprotective effect of EriB in the treatment of ischemic stroke.
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Diterpenos , Accidente Cerebrovascular Isquémico , Fármacos Neuroprotectores , Ratones , Animales , Microglía , FN-kappa B/metabolismo , Enfermedades Neuroinflamatorias , Fármacos Neuroprotectores/farmacología , Infarto de la Arteria Cerebral Media/tratamiento farmacológicoRESUMEN
BACKGROUND: Sympathetic overactivation plays an important role in heart failure (HF)-induced ventricular arrhythmias (VAs). Microglia-mediated neuroinflammation could contribute to sympathetic overactivation. A previous study demonstrated that low-intensity pulsed ultrasound (LIPUS) could inhibit neuroinflammation. However, whether LIPUS could attenuate HF-induced VAs via inhibiting microglia-mediated neuroinflammation remains largely unknown. METHODS: Forth Sprague-Dawley male rats were averagely randomized into four groups: CTL (control) group, CTL + LIPUS group, HF group and HF + LIPUS. Surgical ligation of the coronary artery was used for induction of HF. In vivo electrophysiological study was performed to check VAs susceptibility. Left stellate ganglion (LSG) neural activity and heart rate variability (HRV) were used to test sympathetic nerve activity. RESULTS: Compared to the HF group, LIPUS treatment significantly ameliorated HF-induced cardiac hypertrophy, fibrosis, and dysfunction. In addition, LIPUS treatment markedly inhibited HF-induced VAs susceptibility and reversed gap junction remodeling. LIPUS treatment obviously inhibited microglial activation and neuroinflammation in PVN, sympathetic hyperactivity in the LSG and proinflammatory cytokines releases in the ventricle. P2X7/NLRP3 signaling pathway may be involved in the anti-arrhythmic effect of LIPUS treatment following HF. CONCLUSIONS: Our data demonstrated that LIPUS treatment protected against HF-induced VAs via alleviating microglia-mediated neuroinflammation, sympathetic overactivation and proinflammatory cytokines releases through inhibiting P2X7/NLRP3 signaling. This study provides novel insight into the therapeutic potential of LIPUS.
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Insuficiencia Cardíaca , Microglía , Masculino , Ratas , Animales , Microglía/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Enfermedades Neuroinflamatorias , Ratas Sprague-Dawley , Arritmias Cardíacas/terapia , Insuficiencia Cardíaca/terapia , Insuficiencia Cardíaca/metabolismo , Ondas Ultrasónicas , Citocinas/metabolismoRESUMEN
Vascular aging is a major risk factor for age-related cardiovascular diseases, which have high rates of morbidity and mortality. It is characterized by changes in the blood vessels, such as macroscopically increased vascular diameter and intima-medial thickness, chronic inflammation, vascular calcification, arterial stiffening, and atherosclerosis. DNA damage and the subsequent various DNA damage response (DDR) pathways are important causative factors of vascular aging. Deficient DDR, which may result in the accumulation of unrepaired damaged DNA or mutations, can lead to vascular aging. On the other hand, over-activation of some DDR proteins, such as poly (ADP ribose) polymerase (PARP) and ataxia telangiectasia mutated (ATM), also can enhance the process of vascular aging, suggesting that DDR can have both positive and negative effects on vascular aging. Despite the evidence reviewed in this paper, the role of DDR in vascular aging and potential therapeutic targets remain poorly understood and require further investigation.
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Reparación del ADN , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Humanos , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Daño del ADN , Envejecimiento/genética , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismoRESUMEN
Recent findings suggest an important role for the dysregulation of stromal interaction molecule (STIM) proteins, activators of store-operated Ca2+ channels, and the prolonged activation of N-methyl-D-aspartate receptors (NMDARs) in the development of neurodegenerative diseases. We previously demonstrated that STIM silencing increases Ca2+ influx through NMDAR and STIM-NMDAR2 complexes are present in neurons. However, the interplay between NMDAR subunits (GluN1, GluN2A, and GluN2B) and STIM1/STIM2 with regard to intracellular trafficking remains unknown. Here, we found that the activation of NMDAR endocytosis led to an increase in STIM2-GluN2A and STIM2-GluN2B interactions in primary cortical neurons. STIM1 appeared to migrate from synaptic to extrasynaptic sites. STIM2 silencing inhibited post-activation NMDAR translocation from the plasma membrane and synaptic spines and increased NMDAR currents. Our findings reveal a novel molecular mechanism by which STIM2 regulates NMDAR synaptic trafficking by promoting NMDAR endocytosis after receptor overactivation, which may suggest protection against excessive uncontrolled Ca2+ influx through NMDARs.
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Receptores de N-Metil-D-Aspartato , Transducción de Señal , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Neuronas/metabolismo , Transporte Iónico , EndocitosisRESUMEN
Reperfusion injury presents a significant obstacle to neuronal survival following successful recanalization in ischemic stroke, which is characterized by intricate pathophysiological processes comprising numerous interconnected pathways. Oxidative stress-induced neuronal ferroptosis and the overactivation of glial cells play important roles in this phenomenon. In this study, we developed a targeted cross-linked micelle loaded with idebenone to rescue the ischemic penumbra by inhibiting neuronal ferroptosis and glial overactivation. In rat models, the CREKA peptide-modified micelles accumulate in the damaged brain via binding to microthrombi in the ipsilateral microvessels. Upon reactive oxygen species (ROS) stimulation, diselenide bonds within the micelles are transformed to hydrophilic seleninic acids, enabling synchronized ROS consumption and responsive drug release. The released idebenone scavenges ROS, prevents oxidative stress-induced neuronal ferroptosis, attenuates glial overactivation, and suppresses pro-inflammatory factors secretion, thereby modulating the inflammatory microenvironment. Finally, this micelle significantly reinforces neuronal survival, reduces infarct volume, and improves behavioral function compared to the control groups. This pleiotropic therapeutic micelle provides a proof-of-concept of remodeling the lesion microenvironment by inhibiting neuronal ferroptosis and glial overactivation to treat cerebral ischemia-reperfusion injury.
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Ferroptosis , Daño por Reperfusión , Animales , Ratas , Micelas , Especies Reactivas de Oxígeno , Neuroglía , Daño por Reperfusión/tratamiento farmacológicoRESUMEN
Stimulator of interferon genes (STING) mediates the innate immune response against damaged endogenous double-strand DNA and exogenous virus infection. The location of STING is critical to the accurate control of defence signalling pathways. Recently, the effects of extracellular vesicles (EVs) in the regulation of innate immune signalling have been reported. Nevertheless, the particular roles played by STING in EVs and the related mechanisms have remained largely unknown. Herein, we report that when STING was activated in cells, EVs derived from these cells carried STING oligomers. Signal transducing adapter molecule 1 (STAM) was found to be a STING transporter that directly interacted with STING and facilitated STING transport into EVs. Importantly, the translocation of STING into EVs was a mechanism by which STING was degraded, suppressing the innate immune response. In summary, we elucidated the mechanism and function of the translocation of STING into EVs, adding to the understanding of STING activity regulation.
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Vesículas Extracelulares , Proteínas de la Membrana , Proteínas de la Membrana/metabolismo , Vesículas Extracelulares/metabolismo , Inmunidad Innata , ADN/metabolismo , Transducción de SeñalRESUMEN
Parkinson's disease (PD) is a common neurodegenerative disorder caused by dopaminergic neuron progressive degeneration. Inhibition of microglial activation may contribute to the treatment and prevention of PD. Plantamajoside (PMS) is a natural compound extracted from plantain seeds. It has a wide range of biological activities, including anti-inflammatory, antioxidative, as well as antitumor effects. However, its possible effects on PD are still unclear. In this study, lipopolysaccharide (LPS) was first injected into the right midbrain substantia nigra (SN) of male C57BL/6 mice to establish the PD mouse model. We found that PMS improved LPS-induced behavioral dysfunction in PD mice. PMS attenuated LPS-induced SN injury in PD mice. PMS could suppress LPS-induced microglial overactivation in PD mice. In addition, MS inhibited LPS-induced activation of the HDAC2/MAPK pathway in PD mice and BV-2 cells. It further revealed that PMS alleviated microglia polarization by inhibiting HDAC2. The limitation of this study was the lack of experiments for investigating the further molecular mechanism and in vivo animal validation, which needs to be further confirmed in the future. Collectively, our data suggested that PMS could serve as a promising drug for PD.
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Enfermedad de Parkinson , Ratones , Masculino , Animales , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Microglía , Lipopolisacáridos/toxicidad , Ratones Endogámicos C57BL , Sustancia Negra/metabolismo , Neuronas Dopaminérgicas/metabolismo , Modelos Animales de Enfermedad , Histona Desacetilasa 2/metabolismoRESUMEN
A common observation in fMRI studies using the BOLD signal is that older adults, compared with young adults, show overactivations, particularly during less demanding tasks. The neuronal underpinnings of such overactivations are not known, but a dominant view is that they are compensatory in nature and involve recruitment of additional neural resources. We scanned 23 young (20-37 years) and 34 older (65-86 years) healthy human adults of both sexes with hybrid positron emission tomography/MRI. The radioligand [18F]fluoro-deoxyglucose was used to assess dynamic changes in glucose metabolism as a marker of task-dependent synaptic activity, along with simultaneous fMRI BOLD imaging. Participants performed two verbal working memory (WM) tasks: one involving maintenance (easy) and one requiring manipulation (difficult) of information in WM. Converging activations to the WM tasks versus rest were observed for both imaging modalities and age groups in attentional, control, and sensorimotor networks. Upregulation of activity to WM-demand, comparing the more difficult to the easier task, also converged between both modalities and age groups. For regions in which older adults showed task-dependent BOLD overactivations compared with the young adults, no corresponding increases in glucose metabolism were found. To conclude, findings from the current study show that task-induced changes in the BOLD signal and synaptic activity as measured by glucose metabolism generally converge, but overactivations observed with fMRI in older adults are not coupled with increased synaptic activity, which suggests that these overactivations are not neuronal in origin.SIGNIFICANCE STATEMENT Findings of increased fMRI activations in older compared with younger adults have been suggested to reflect increased use of neuronal resources to cope with reduced brain function. The physiological underpinnings of such compensatory processes are poorly understood, however, and rest on the assumption that vascular signals accurately reflect neuronal activity. Comparing fMRI and simultaneously acquired functional positron emission tomography as an alternative index of synaptic activity, we show that age-related overactivations do not appear to be neuronal in origin. This result is important because mechanisms underlying compensatory processes in aging are potential targets for interventions aiming to prevent age-related cognitive decline.
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Imagen por Resonancia Magnética , Memoria a Corto Plazo , Masculino , Femenino , Adulto Joven , Humanos , Anciano , Memoria a Corto Plazo/fisiología , Imagen por Resonancia Magnética/métodos , Envejecimiento/fisiología , Cognición/fisiología , Glucosa , EncéfaloRESUMEN
The carotid body (CB) is a prototypical acute oxygen (O2 )-sensing organ that mediates reflex hyperventilation and increased cardiac output in response to hypoxaemia. CB overactivation, secondary to the repeated stimulation produced by the recurrent episodes of intermittent hypoxia, is believed to contribute to the pathogenesis of sympathetic hyperactivity present in sleep apnoea patients. Although CB functional plasticity induced by chronic intermittent hypoxia (CIH) has been demonstrated, the underlying mechanisms are not fully elucidated. Here, we show that CIH induces a small increase in CB volume and rearrangement of cell types in the CB, characterized by a mobilization of immature quiescent neuroblasts, which enter a process of differentiation into mature, O2 -sensing and neuron-like, chemoreceptor glomus cells. Prospective isolation of individual cell classes has allowed us to show that maturation of CB neuroblasts is paralleled by an upregulation in the expression of specific glomus cell genes involved in acute O2 -sensing. CIH enhances mitochondrial responsiveness to hypoxia in maturing neuroblasts as well as in glomus cells. These data provide novel perspectives on the pathogenesis of CB-mediated sympathetic overflow that may lead to the development of new pharmacological strategies of potential applicability in sleep apnoea patients. KEY POINTS: Obstructive sleep apnoea is a frequent condition in the human population that predisposes to severe cardiovascular and metabolic alterations. Activation of the carotid body, the main arterial oxygen-sensing chemoreceptor, by repeated episodes of hypoxaemia induces exacerbation of the carotid body-mediated chemoreflex and contributes to sympathetic overflow characteristic of sleep apnoea patients. In rats, chronic intermittent hypoxaemia induces fast neurogenesis in the carotid body with rapid activation of neuroblasts, which enter a process of proliferation and maturation into O2 -sensing chemoreceptor glomus cells. Maturing carotid body neuroblasts and glomus cells exposed to chronic intermittent hypoxia upregulate genes involved in acute O2 sensing and enhance mitochondrial responsiveness to hypoxia. These findings provide novel perspectives on the pathogenesis of carotid body-mediated sympathetic hyperactivation. Pharmacological modulation of carotid body fast neurogenesis could help to ameliorate the deleterious effects of chronic intermittent hypoxaemia in sleep apnoea patients.
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Cuerpo Carotídeo , Apnea Obstructiva del Sueño , Ratas , Humanos , Animales , Cuerpo Carotídeo/metabolismo , Hipoxia , Oxígeno/metabolismo , NeurogénesisRESUMEN
BACKGROUND: Cardiovascular disease is one of the most concerning chronic diseases in the world. Many studies have shown that platelet overactivation is a very important factor in the occurrence and development of cardiovascular diseases. At present, the widely used antiplatelet drugs have some defects, such as drug resistance and adverse reactions. PURPOSE: The purpose of this article is to summarize the main mechanisms and pathways of platelet activation, the main targets of antiplatelet aggregation, and the antiplatelet aggregation components of natural drugs and their mechanisms of action to provide new research ideas for the development and application of antiplatelet drugs. STUDY DESIGN AND METHODS: In this review, we systematically searched the PubMed, Google Scholar, Web of Science, and CNKI databases and selected studies based on predefined eligibility criteria. We then assessed their quality and extracted data. RESULTS: ADP, AA, THR, AF, collagen, SDF-1α, and Ca2+ can induce platelet aggregation and trigger thrombosis. Natural drugs have a good inhibitory effect on platelet activation. More than 50 kinds of natural drugs and over 120 kinds of chemical compounds, including flavonoids, alkaloids, saponins, terpenoids, coumarins, and organic acids, have significantly inhibited platelet activation activity. The MAPK pathway, cGMP-PKG pathway, cAMP-PKA pathway, PI3K-AKT pathway, PTK pathway, PLC pathway, and AA pathway are the main mechanisms and pathways of platelet activation. CONCLUSION: Natural drugs and their active ingredients have shown good activity and application prospects in anti-platelet aggregation. We hope that this review provides new research ideas for the development and application of antiplatelet drugs.