RESUMEN
Enkephalins are reportedly correlated with heart function. However, their regulation in the heart remains unexplored. This study revealed a substantial increase in circulating levels of opioid growth factor (OGF) (also known as methionine enkephalin) and myocardial expression levels of both OGF and its receptor (OGFR) in subjects treated with doxorubicin (Dox). Silencing OGFR through gene knockout or using adeno-associated virus serotype 9 carrying small hairpin RNA effectively alleviated Dox-induced cardiotoxicity (DIC) in mice. Conversely, OGF supplementation exacerbated DIC manifestations, which could be abolished by administration of the OGFR antagonist naltrexone (NTX). Mechanistically, the previously characterized OGF/OGFR/P21 axis was identified to facilitate DIC-related cardiomyocyte apoptosis. Additionally, OGFR was observed to dissociate STAT1 from the promoters of ferritin genes (FTH and FTL), thereby repressing their transcription and exacerbating DIC-related cardiomyocyte ferroptosis. To circumvent the compromised therapeutic effects of Dox on tumors owing to OGFR blockade, SiO2-based modifiable lipid nanoparticles were developed for heart-targeted delivery of NTX. The pretreatment of tumor-bearing mice with the assembled NTX nanodrug successfully provided cardioprotection against Dox toxicity without affecting Dox therapy in tumors. Taken together, this study provides a novel understanding of Dox cardiotoxicity and sheds light on the development of cardioprotectants for patients with tumors receiving Dox treatment.
Asunto(s)
Cardiotoxicidad , Doxorrubicina , Miocitos Cardíacos , Animales , Doxorrubicina/efectos adversos , Ratones , Cardiotoxicidad/metabolismo , Cardiotoxicidad/prevención & control , Cardiotoxicidad/genética , Cardiotoxicidad/etiología , Cardiotoxicidad/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Humanos , Apoptosis/efectos de los fármacos , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Receptores Opioides/metabolismo , Receptores Opioides/genética , Masculino , Transducción de Señal/efectos de los fármacos , Nanopartículas , Ratones Endogámicos C57BLRESUMEN
OBJECTIVE: This study aimed to investigate the underlying regulatory effects of methionine enkephalin (MENK) on osteosarcoma. METHODS: The Cell Counting Kit-8 assay, clone formation, wound healing, transwell assay, and flow cytometry were performed to measure the effects of MENK on the proliferation, migration, invasion, and apoptosis of MG-63 and Saos-2 cells. Opiate growth factor receptor expression (OGFr) in cells was stably knocked down using siRNA. A tumor model was established by inoculating MG-63 cells into mice. Flow cytometry was performed to identify alterations in mice bone marrow, spleen, and tumor tissue immune cells. The phenotype of tumor-associated macrophages was determined using immunohistochemistry. After OGFr knockdown or/and treatment with MENK, Bax, Bcl-2, caspase 3, caspase 9, and PARP expression levels were characterized using qRT-PCR, western blot, and WES, respectively. RESULTS: MENK could significantly inhibit the proliferation, invasion, and migration of MG-63 and Saos-2, arrest the cell cycle in the G0/G1 phase, upregulate Bax, caspase 3, caspase 9, and PARP expression, and downregulate Bcl-2 expression. Tumor size and weight were lower in the MENK group than those in the control group. MENK-treated mice exhibited a reduced ratio of CD11b + Gr-1 + myeloid-derived suppressor cells. MENK increased the ratio of M1-type macrophages and decreased the proportion of M2-type macrophages in tumor tissue. Furthermore, the level of TNF-α significantly increased while that of IL-10 decreased in MENK-treated mice. The effect of MENK could be partly reversed by OGFr knockdown. CONCLUSION: MENK reduces the abundance of myeloid-derived suppressor cells, induces M1 polarization of macrophages, and exhibits an inhibitory effect on osteosarcoma.
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Neoplasias Óseas , Osteosarcoma , Animales , Ratones , Caspasa 3 , Caspasa 9 , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Proteína X Asociada a bcl-2 , Osteosarcoma/tratamiento farmacológico , Encefalina Metionina/farmacología , Encefalina Metionina/uso terapéutico , Neoplasias Óseas/tratamiento farmacológicoRESUMEN
Novel prophylactic drugs and vaccination strategies for protection against influenza virus should induce specific effector T-cell immune responses in pulmonary airways and peripheral lymphoid organs. Designing approaches that promote T-cell-mediated responses and memory T-cell differentiation would strengthen host resistance to respiratory infectious diseases. The results of this study showed that pulmonary delivery of MENK via intranasal administration reduced viral titres, upregulated opioid receptor MOR and DOR, increased the proportions of T-cell subsets including CD8+ T cells, CD8+ TEM cells, NP/PA-effector CD8+ TEM cells in bronchoalveolar lavage fluid and lungs, and CD4+/CD8+ TCM cells in lymph nodes to protect mice against influenza viral challenge. Furthermore, we demonstrated that, on the 10th day of infection, the proportions of CD4+ TM and CD8+ TM cells were significantly increased, which meant that a stable TCM and TEM lineage was established in the early stage of influenza infection. Collectively, our data suggested that MENK administered intranasally, similar to the route of natural infection by influenza A virus, could exert antiviral activity through upregulating T-cell-mediated adaptive immune responses against influenza virus.
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Virus de la Influenza A , Gripe Humana , Ratones , Animales , Humanos , Linfocitos T CD8-positivos , Encefalina Metionina/farmacología , Células T de Memoria , Memoria Inmunológica , Ratones Endogámicos C57BLRESUMEN
This study was to study the role of methionine enkephalin (menk) in cell invasion and migration as well as NK cells activation of tumor microenvironment in cervical cancer. The results showed that menk inhibited cervical cancer migration and invasion. In addition, we found menk affected epithelial to mesenchymal transition (EMT) related indicators, with increasing E-cadherin level, decreasing N-cadherin and vimentin level. Through in vivo mouse model, we found that menk IFNγ and NKP46 expression was upregulated in tumor tissues by menk compared with controls, while LAG3 expression was inhibited by menk, besides, there was an upregulation of CD11b+ NCR1+ NKs of tumor microenvironment in cervical cancer. Therefore, we concluded that menk inhibited cancer migration and invasion via affecting EMT related indicators and activated CD11b+ NCR1+ NKs of tumor microenvironment in cervical cancer, laying a theoretical foundation for the further clinical treatment of menk.
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Neoplasias del Cuello Uterino , Humanos , Femenino , Ratones , Animales , Neoplasias del Cuello Uterino/tratamiento farmacológico , Encefalina Metionina/farmacología , Transición Epitelial-Mesenquimal , Microambiente Tumoral , Receptor 1 Gatillante de la Citotoxidad Natural , Línea Celular Tumoral , Movimiento CelularRESUMEN
Although methionine-enkephalin (M-ENK) is implicated in the regulation of reproductive functions in vertebrates, its function in reptiles is little understood. This study aims to elucidate the role of M-ENK on seasonal and follicle stimulating hormone (FSH)-induced ovarian recrudescence in the gecko Hemidactylus frenatus. In the first experiment, administration of 5 µg M-ENK did not affect germinal bed activity or follicular developmental stages I, II, and III (previtellogenic) and IV (vitellogenic), but there were no stage V (vitellogenic) follicles in the ovary. However, there was a significant decrease in the mean numbers of oogonia and primary oocytes in the germinal bed associated with the complete absence of stage IV and V follicles in 25 µg M-ENK-treated lizards in contrast to experimental controls. Furthermore, there was a significant decrease in gonadotropin-releasing hormone - immunoreactive (GnRH-ir) content in the median eminence (ME) and pars distalis (PD) of the pituitary gland and sparse labelling of hypothalamic GnRH-ir neurons in 25 µg M-ENK-treated lizards. In the second experiment, treatment with FSH during the regression phase of the ovarian cycle resulted in the appearance of stage IV and V follicles, in contrast to their absence in the initial controls and treatment controls. However, treatment with 25 µg M-ENK + FSH did not result in the appearance of these follicles, indicating the inhibitory effect of M-ENK on FSH-induced ovarian recrudescence. These findings suggest that M-ENK inhibits the germinal bed and vitellogenic follicular growth in a dose-dependent manner, possibly mediated through the suppression of GnRH release in the ME and PD. In addition, M-ENK may also act at the level of the ovary in the gecko.
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Lagartos , Ovario , Femenino , Animales , Hormona Folículo Estimulante/farmacología , Analgésicos Opioides/farmacología , Folículo Ovárico , Encefalina Metionina/farmacología , Estaciones del Año , Hormona Liberadora de Gonadotropina/farmacología , Lagartos/fisiología , Metionina/farmacologíaRESUMEN
In the central nervous system, longterm effects of a vagotomy include disturbance of monoaminergic activity of the limbic system. Since low vagal activity is observed in major depression and autism spectrum disorder, the study aimed to determine whether animals fully recovered after subdiaphragmatic vagotomy demonstrates neurochemical indicators of altered wellbeing and social component of sickness behavior. Bilateral vagotomy or sham surgery was performed in adult rats. After one month of recovery, rats were challenged with lipopolysaccharide or vehicle to determine the role of central signaling upon sickness. Striatal monoamines and metenkephalin concentrations were evaluated using HPLC and RIA methods. We also defined a concentration of immunederived plasma metenkephalin to establish a longterm effect of vagotomy on peripheral analgesic mechanisms. The data indicate that 30 days after vagotomy procedure, striatal dopaminergic, serotoninergic, and enkephalinergic neurochemistry was altered, both under physiological and inflammatory conditions. Vagotomy prevented inflammationinduced increases of plasma metenkephalin - an opioid analgesic. Our data suggest that in a long perspective, vagotomized rats may be more sensitive to pain and social stimuli during peripheral inflammation.
Asunto(s)
Trastorno del Espectro Autista , Encefalina Metionina , Ratas , Animales , Encefalina Metionina/farmacología , Vagotomía , Nervio Vago/fisiología , Inflamación , AminasRESUMEN
Metastasis is one of the most difficult challenges for clinical lung cancer treatment. Epithelial-mesenchymal transition (EMT) is the crucial step of tumor metastasis. Immune cells in the tumor microenvironment (TME), such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), promote cancer cell EMT. In this study, we explored the effect of methionine enkephalin (MENK) on the EMT process in vitro and in vivo, and its influence on TAMs, MDSCs, and associated cytokines in vivo. The results showed that MENK suppressed growth, migration, and invasion of lung cancer cells and inhibited the EMT process by interacting with opioid growth factor receptor. MENK reduced the number of M2 macrophages and MDSC infiltration, and downregulated the expression of interleukin-10 and transforming growth factor-ß1 in both primary and metastatic tumors of nude mice. The present findings suggest that MENK is a potential target for suppressing metastasis in lung cancer treatment.
Asunto(s)
Neoplasias Pulmonares , Células Supresoras de Origen Mieloide , Animales , Ratones , Transición Epitelial-Mesenquimal , Macrófagos Asociados a Tumores/metabolismo , Encefalina Metionina/farmacología , Encefalina Metionina/uso terapéutico , Encefalina Metionina/metabolismo , Microambiente Tumoral , Ratones Desnudos , Línea Celular Tumoral , Movimiento CelularRESUMEN
AIMS: Obesity and its related metabolic disorders, including insulin resistance and fatty liver, have become a serious global public health problem. Previous studies have shown Methionine Enkephalin (MetEnk) has the potential on adipocyte browning, however, its effects on the potential mechanisms of its regulation in browning as well as its improvement in energy metabolic homeostasis remain to be deciphered. MAIN METHODS: C57BL/6J male mice were fed with high-fat diet (HFD) to induce obesity model, and MetEnk was injected subcutaneously to detect changes in the metabolic status of mice, adipocytes and HepG2 cells were also treated with MetEnk, and transcriptomic, metabolomic were used to detect the changes of lipid metabolism, mitochondrial function, inflammation and other related factors. KEY FINDINGS: We found that MetEnk effectively protected against obesity weight gain in HFD-induced C57BL/6J mice, significantly improved glucose tolerance and insulin sensitivity, reduced the expression levels of interleukin 6 (IL-6), promoted white fat browning, moreover, using a combination of transcriptomic, metabolomic and inhibitors, it was found that MetEnk improved mitochondrial function, promoted thermogenesis and lipolysis by activating cAMP/PKA pathway in adipocytes, further analysis found that MetEnk also promoted lipolysis and alleviated inflammation through AMP-activated protein kinase (AMPK) pathway in mice liver and HepG2 cells. SIGNIFICANCE: Our study provides profound evidence for the role of MetEnk in improving lipid metabolism disorders. This study provides a mechanical foundation for investigating the potential of MetEnk to improve obesity and its associated metabolic disorders.
Asunto(s)
Encefalina Metionina , Resistencia a la Insulina , Masculino , Ratones , Animales , Encefalina Metionina/farmacología , Ratones Endogámicos C57BL , Tejido Adiposo Blanco/metabolismo , Termogénesis , Dieta Alta en Grasa/efectos adversos , Obesidad/metabolismo , Inflamación/metabolismo , Tejido Adiposo Pardo/metabolismoRESUMEN
Venom-derived NaV1.7 channel blockers have promising prospects in pain management. The 34-residue tarantula peptide GpTx-1 is a potent NaV1.7 channel blocker. Its powerful analog [Ala5, Phe6, Leu26, Arg28]GpTx-1 (GpTx-1-71) displayed excellent NaV1.7 selectivity and analgesic properties in mice. The current study aimed to elucidate the anti-hyperalgesic activities of GpTx-1-71 in inflammatory pain and reveal the underlying mechanisms. Our results demonstrated that intrathecal and intraplantar injections of GpTx-1-71 dose-dependently attenuated CFA-induced inflammatory hypersensitivity in rats. Moreover, GpTx-1-71-induced anti-hyperalgesia was significantly reduced by opioid receptor antagonists and the enkephalin antibody and diminished in proenkephalin (Penk) gene knockout animals. Consistently, GpTx-1-71 treatment increased the enkephalin level in the spinal dorsal horn and promoted the Penk transcription and enkephalin release in primary dorsal root ganglion (DRG) neurons, wherein sodium played a crucial role in these processes. Mass spectrometry analysis revealed that GpTx-1-71 mainly promoted the secretion of Met-enkephalin but not Leu-enkephalin from DRG neurons. In addition, the combination of subtherapeutic Met-enkephalin and GpTx-1-71 produced synergistic anti-hyperalgesia in CFA-induced inflammatory hypersensitivity. These findings suggest that the endogenous enkephalin pathway is essential for GpTx-1-71-induced spinal and peripheral analgesia in inflammatory pain. PERSPECTIVE: This article presents a possible pharmacological mechanism underlying NaV1.7 blocker-induced analgesia in inflammatory pain, which helps us to better understand and develop venom-based painkillers for incurable pain.
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Hiperalgesia , Dolor , Ratas , Ratones , Animales , Dolor/tratamiento farmacológico , Hiperalgesia/tratamiento farmacológico , Analgésicos/farmacología , Analgésicos/uso terapéutico , Encefalinas/metabolismo , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Encefalina Metionina/uso terapéutico , Ganglios Espinales/metabolismo , Canal de Sodio Activado por Voltaje NAV1.7/metabolismoRESUMEN
Low dopamine D2 receptor (D2R) availability in the striatum can predispose for cocaine abuse; though how low striatal D2Rs facilitate cocaine reward is unclear. Overexpression of D2Rs in striatal neurons or activation of D2Rs by acute cocaine suppresses striatal Penk mRNA. Conversely, low D2Rs in D2-striatal neurons increases striatal Penk mRNA and enkephalin peptide tone, an endogenous mu-opioid agonist. In brain slices, met-enkephalin and inhibition of enkephalin catabolism suppresses intra-striatal GABA transmission. Pairing cocaine with intra-accumbens met-enkephalin during place conditioning facilitates acquisition of preference, while mu-opioid receptor antagonist blocks preference in wild-type mice. We propose that heightened striatal enkephalin potentiates cocaine reward by suppressing intra-striatal GABA to enhance striatal output. Surprisingly, a mu-opioid receptor antagonist does not block cocaine preference in mice with low striatal D2Rs, implicating other opioid receptors. The bidirectional regulation of enkephalin by D2R activity and cocaine offers insights into mechanisms underlying the vulnerability for cocaine abuse.
Asunto(s)
Trastornos Relacionados con Cocaína , Cocaína , Analgésicos Opioides/farmacología , Animales , Cocaína/farmacología , Trastornos Relacionados con Cocaína/metabolismo , Cuerpo Estriado/metabolismo , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Encefalinas/metabolismo , Encefalinas/farmacología , Ratones , Antagonistas de Narcóticos/metabolismo , Antagonistas de Narcóticos/farmacología , ARN Mensajero/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Recompensa , Ácido gamma-Aminobutírico/metabolismoRESUMEN
There is evidence that methionine enkephalin (MENK), an opioid peptide, promotes anti-tumor immune responses. In this study, the effect of MENK on colorectal cancer (CRC) and its mechanisms of action were examined in vivo. The intraperitoneal administration of 20 mg/kg MENK effectively inhibited MC38 subcutaneous colorectal tumor growth in mice. MENK inhibited tumor progression by increasing the immunogenicity and recognition of MC38 cells. MENK down-regulated the oncogene Kras and anti-apoptotic Bclxl and Bcl2, suppressed Il1b, Il6, iNOS, and Arg1 (encoding inflammatory cytokines), and increased Il17a and Il10 levels. MENK promoted a tumor suppressive state by decreasing the immune checkpoints Pd-1, Pd-l1, Lag3, Flgl1, and 2b4 in CRC. MENK also altered the immune status of the tumor immune microenvironment (TIME). It increased the infiltration of M1-type macrophages, CD8+T cells, and CD4+T cells and decreased the proportions of G-MDSCs, M-MDSCs, and M2-type macrophages. MENK accelerated CD4+TEM and CD8+TEM cell activation in the TIME and up-regulated IFN-γ, TNF-α, and IL-17A in CD4+T cells and Granzyme B in CD8+T cells. In addition, analyses of PD-1 and PD-L1 expression indicated that MENK promoted the anti-tumor immune response mediated by effector T cells. Finally, OGFr was up-regulated at the protein and mRNA levels by MENK, and the inhibitory effects of MENK on tumor growth were blocked by NTX, a specific blocker of OGFr. These finding indicate that MENK remodels the TIME in CRC to inhibit tumor progression by binding to OGFr. MENK is a potential therapeutic agent for CRC, especially for improving the efficacy of immunotherapy.
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Neoplasias Colorrectales , Encefalina Metionina , Animales , Antígeno B7-H1 , Neoplasias Colorrectales/tratamiento farmacológico , Encefalina Metionina/farmacología , Encefalina Metionina/uso terapéutico , Factores Inmunológicos , Ratones , Receptor de Muerte Celular Programada 1 , Microambiente TumoralRESUMEN
Immunotherapy for cervical carcinoma is becoming increasingly important recently. In these studies methionine enkephalin (menk) is shown to inhibit cervical tumor cell proliferation in vitro in association with an increase in the expression of apoptosis markers and mediators, including an increase in fas, caspase 8, and caspase 3 expression and intrinsic expression of the signaling pathway mediator bax. In vivo, tumor growth was restrained in mice xenotransplant model with typical pathological features of apoptosis. Furthermore, myeloid derived suppressor cells (MDSCs) had a significant decrease in circulation and in tumor site. In brief, these findings showed menk could inhibit tumor growth in vitro and in vivo, providing direction of further research and clinical application prospect.
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Carcinoma , Células Supresoras de Origen Mieloide , Neoplasias del Cuello Uterino , Animales , Apoptosis , Línea Celular Tumoral , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Encefalina Metionina/uso terapéutico , Femenino , Humanos , Factores Inmunológicos/metabolismo , Ratones , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/metabolismoRESUMEN
Cold-inducible RNA-binding protein (CIRBP) is documented to be required for maintaining cardiac function, however, its role in chemotherapy-induced cardiotoxicity remains obscured. Herein, we report that CIRBP decreases cardiomyocyte apoptosis and attenuates cardiotoxicity through disrupting OGF-OGFR signal. CIRBP deficiency is involved in diverse chemotherapeutic agents induced cardiomyocyte apoptosis. Delivery of exogenous CIRBP to the mouse myocardium significantly mitigated doxorubicin-induced cardiac apoptosis and dysfunction. Specifically, OGFR was identified as a downstream core effector responsible for chemotherapy-induced cardiomyocyte apoptosis. CIRBP was shown to interact with OGFR mRNA and to repress OGFR expression by reducing mRNA stability. CIRBP-mediated cytoprotection against doxorubicin-induced cardiac apoptosis was demonstrated to largely involve OGFR repression by CIRBP. NTX as a potent antagonist of OGFR successfully rescued CIRBP ablation-rendered susceptibility to cardiac dyshomeostasis upon exposure to doxorubicin, whereas another antagonist ALV acting only on opioid receptors did not. Taken together, our results demonstrate that CIRBP confers myocardium resistance to chemotherapy-induced cardiac apoptosis and dysfunction by dampening OGF/OGFR axis, shedding new light on the mechanisms of chemo-induced cardiotoxicity and providing insights into the development of an efficacious cardioprotective strategy for cancer patients.
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Cardiotoxicidad , Doxorrubicina , Encefalina Metionina , Animales , Apoptosis/efectos de los fármacos , Cardiotoxicidad/etiología , Cardiotoxicidad/metabolismo , Cardiotoxicidad/patología , Proliferación Celular , Doxorrubicina/toxicidad , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Humanos , Ratones , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Proteínas de Unión al ARN/genéticaRESUMEN
Multiple sclerosis (MS) is a progressive disease of the central nervous system (CNS) that primarily affects women during the second or third decade of life. The mechanism is hypothesized to involve unregulated peripheral inflammation resulting in blood-brain barrier damage, and eventual axonal damage and demyelination. Based on this understanding, the animal model of MS, experimental autoimmune encephalomyelitis (EAE), often is utilized to study lymphocyte activation. Therapeutic paradigms of exogenous opioid growth factor (OGF) or low-dose naltrexone (LDN) treatment can modulate EAE, but little is reported regarding OGF or LDN effects on peripheral inflammation, microglia activation, and/or macrophage proliferation. Moreover, little is known about differential responses to LDN or OGF relative to the duration and timing of treatment. Utilizing a female mouse model of EAE, two treatment regimens were established to investigate differences between prophylactic treatment and traditional therapy initiated at the time of disease presentation. Prophylactic OGF or LDN treatment delayed the onset of behavior, suppressed neutrophil replication, and curtailed lymphocyte proliferation which ultimately improved behavioral outcome. Traditional therapy with OGF or LDN reversed behavioral deficits, restored OGF and IL-17 serum levels, and inhibited microglial activation within 8 days. Reduced serum OGF levels in untreated EAE mice correlated with increased microglia activation within lumbar spinal cords. Both treatment regimens of OGF or LDN reduced activated microglia, whereas only prophylactic treatment prevented CNS macrophage aggregation. These data demonstrate that the timing of LDN or OGF treatment initiation alters outcomes and can prevent or reverse behavioral deficits, cytokine activation, and spinal cord pathology.
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Analgésicos Opioides , Encefalomielitis Autoinmune Experimental , Analgésicos Opioides/farmacología , Animales , Encefalomielitis Autoinmune Experimental/patología , Encefalina Metionina/farmacología , Femenino , Humanos , Inmunidad , Ratones , Ratones Endogámicos C57BL , Microglía/patología , Médula Espinal/patologíaRESUMEN
This study examined the antitumor effect of methionine enkephalin (MENK) against lung cancer in vivo and in vitro and explored the underlying mechanisms. Changes in the immune status of the tumor microenvironment (TME) in response to MENK administration were examined in mice. MENK significantly inhibited the proliferation of lung cancer cells in vivo and in vitro by regulating the Wnt/ß-catenin pathway and causing cell cycle arrest at the G0/G1 phase. Knockdown of opioid growth factor receptor abolished the effect of MENK on lung cancer cells. The immune status of the TME of mice differed between the MENK and control groups. MENK increased the infiltration of M1-type macrophages, natural killer cells, CD8+ T cells, CD4+ T cells, and dendritic cells into the TME, and decreased the proportion of myeloid inhibitory cells and M2-type macrophages. Immunohistochemical analysis of the expression of cytokines in the TME showed that MENK upregulated IL-15, IL-21, IFN-γ, and granzyme B and downregulated IL-10 and TGF-ß1 in mice. Taken together, these finding indicate that MENK may be a potential agent for lung cancer treatment in the future, especially for overcoming immune escape and immune resistance.
Asunto(s)
Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología , Animales , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Citocinas/efectos de los fármacos , Células Dendríticas/efectos de los fármacos , Encefalina Metionina/genética , Femenino , Humanos , Neoplasias Pulmonares/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , ARN Interferente Pequeño , Linfocitos T/efectos de los fármacos , Vía de Señalización Wnt/efectos de los fármacosRESUMEN
The antitumor effects of methionine enkephalin (MENK), also known as opioid growth factor (OGF), including its inhibitory effects on cutaneous squamous cell carcinoma (CSCC), have been established. In this study, we determined the precise mechanism by which MENK suppresses CSCC cell growth. In particular, MENK induced G0/G1 cell cycle arrest and promoted apoptosis in CSCC cells via the Bcl-2/Bax/Caspase-3 signaling pathway. Moreover, MENK reduced immunosuppression by downregulating the number of myeloid-derived suppressor cells (MDSCs) and regulating the polarization of tumor-associated macrophages from M2 to M1 in vivo. Furthermore, JAK2/STAT3, an important tumor-promotion and immunosuppression signaling pathway that is involved in MDSC expansion in tumors and macrophage polarization, was inhibited. These findings highlight the potential of the JAK2/STAT3 signaling pathway as a therapeutic target and suggest the clinical application of MENK for CSCC.
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Carcinoma de Células Escamosas/tratamiento farmacológico , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Macrófagos/efectos de los fármacos , Células Supresoras de Origen Mieloide/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Polaridad Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Citocinas/metabolismo , Encefalina Metionina/genética , Femenino , Humanos , Terapia de Inmunosupresión , Janus Quinasa 2/metabolismo , Ratones Endogámicos BALB C , Ratones Desnudos , ARN Interferente Pequeño , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Cutaneous squamous cell carcinoma (CSCC) is a common skin tumour. Due to weak immunogenicity, recurrence is frequent after treatment. In this study, we explored the effects and mechanisms of methionine enkephalin (MENK), an endogenous opioid peptide and negative growth regulator, in CSCC. MENK inhibited A431 cell proliferation and promoted apoptosis through the opioid growth factor receptor (OGFr). Importantly, MENK also induced autophagy in CSCC and stimulated the emission of DAMPs in A431 cells, which resulted in enhanced activation of dendritic cells (DC).In conclusion, MENK provides an effective method with therapeutic potential to modulate the CSCC microenvironment by utilizing autophagy in the cancer cells.
Asunto(s)
Carcinoma de Células Escamosas/tratamiento farmacológico , Células Dendríticas/inmunología , Encefalina Metionina/farmacología , Antígenos de Histocompatibilidad Clase II/inmunología , Neoplasias Cutáneas/tratamiento farmacológico , Animales , Autofagia/efectos de los fármacos , Carcinoma de Células Escamosas/inmunología , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Proliferación Celular , Femenino , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Ratones , Ratones Endogámicos BALB C , Neurotransmisores/farmacología , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The emergence of the plasmid-mediated colistin resistance mechanism (mcr-1) makes bacterial resistance to colistin increasingly serious. This mcr-1 mediated bacterial resistance to colicin is conferred primarily through modification of lipid A in lipopolysaccharides (LPS). In our previous research, antimicrobial peptide F1 was derived from Tibetan kefir and has been shown to effectively inhibit the growth of Gram-negative bacteria (E. coli), Gram-positive bacteria (Staphylococcus aureus), and other pathogenic bacteria. Based on this characteristic of antibacterial peptide F1, we speculated that it could inhibit the growth of the colicin-resistant E. coli SHP45 (mcr-1) and not easily produce drug resistance. Studies have shown that antimicrobial peptide F1 can destroy the liposome structure of the phospholipid bilayer by destroying the inner and outer membranes of bacteria, thereby significantly inhibiting the growth of E. coli SHP45 (mcr-1), but without depending on LPS. The results of this study confirmed our hypothesis, and we anticipate that antimicrobial peptide F1 will become a safe antibacterial agent that can assist in solving the problem of drug resistance caused by colistin.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Encefalina Metionina/análogos & derivados , Escherichia coli/efectos de los fármacos , Precursores de Proteínas/farmacología , Colistina/farmacología , Encefalina Metionina/farmacología , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Pruebas de Sensibilidad MicrobianaRESUMEN
Multiple sclerosis is a chronic progressive neurological disorder that has few distinctive biomarkers associated with disease progression or response to therapy. This research investigated whether non-invasive imaging correlated with animal behavior and morphological indicators of disease in response to serum levels of [Met5]-enkephalin. Using the experimental autoimmune encephalomyelitis (EAE) model, adult female C57BL/6 J mice were randomized to receive daily injections of 0.1 mg/kg naltrexone (NTX) (= low dose naltrexone, LDN), 10 mg/kg Opioid Growth Factor (OGF) (chemically termed [Met5]-enkephalin) or saline beginning at the time of disease induction. Daily composite behavior scores were recorded over a 30-day period based on tail tone, gait, righting reflex, and limb strength. Prior to disease onset (day 7), and at peak disease (day 18), mice were imaged and tissues (blood and spinal cord) collected at day 30 for serum analyses of OGF and morphology. Serum OGF levels of EAE mice treated with saline were significantly reduced from baseline and from normal mice. Longitudinal cohort data demonstrated an increase in fractional anisotropy in all cohorts by day 18. There was a significant decrease in radial diffusivity in the saline group seen at day 18 whereas the axial diffusivity was not altered amongst treatment groups. Treatment with OGF or LDN resulted in mean diffusivity rates that were comparable to baseline (normal) levels at days 7 and 18. Luxol fast blue staining of the lumbar spinal cords demonstrated a 16 % reduction in myelin staining in saline treated EAE animals when compared to OGF and LDN treated EAE mice. Immunohistochemistry with Olig2 (pan-oligodendrocyte marker) and myelin basic protein (MBP) revealed that OGF and LDN treatment restored the area (%) of MBP and number of oligodendrocytes to that of normal spinal cord (â¼75 %). Saline treated EAE mice had more demyelination and fewer oligodendrocytes than normal mice. Collectively, these data suggest that a panel of biomarkers including imaging, serum biomarker levels, and behavior correlate with progression of disease, and may begin to validate use of specific non-invasive markers for MS.
Asunto(s)
Encefalomielitis Autoinmune Experimental/diagnóstico por imagen , Encefalina Metionina/farmacología , Naltrexona/farmacología , Antagonistas de Narcóticos/farmacología , Médula Espinal/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Imagen de Difusión Tensora , Encefalomielitis Autoinmune Experimental/sangre , Encefalina Metionina/sangre , Femenino , Marcha/efectos de los fármacos , Imagen por Resonancia Magnética , Ratones , Oligodendroglía/efectos de los fármacos , Médula Espinal/diagnóstico por imagenRESUMEN
Opioids and their antagonists alter vitamin C metabolism. Morphine binds to glutathione (l-γ-glutamyl-l-cysteinyl-glycine), an intracellular ascorbic acid recycling molecule with a wide range of additional activities. The morphine metabolite morphinone reacts with glutathione to form a covalent adduct that is then excreted in urine. Morphine also binds to adrenergic and histaminergic receptors in their extracellular loop regions, enhancing aminergic agonist activity. The first and second extracellular loops of adrenergic and histaminergic receptors are, like glutathione, characterized by the presence of cysteines and/or methionines, and recycle ascorbic acid with similar efficiency. Conversely, adrenergic drugs bind to extracellular loops of opioid receptors, enhancing their activity. These observations suggest functional interactions among opioids and amines, their receptors, and glutathione. We therefore explored the relative binding affinities of ascorbic acid, dehydroascorbic acid, opioid and adrenergic compounds, as well as various control compounds, to glutathione and glutathione-like peptides derived from the extracellular loop regions of the human beta 2-adrenergic, dopamine D1, histamine H1, and mu opioid receptors, as well as controls. Some cysteine-containing peptides derived from these receptors do bind ascorbic acid and/or dehydroascorbic acid and the same peptides generally bind opioid compounds. Glutathione binds not only morphine but also naloxone, methadone, and methionine enkephalin. Some adrenergic drugs also bind to glutathione and glutathione-like receptor regions. These sets of interactions provide a novel basis for understanding some ways that adrenergic, opioid and antioxidant systems interact during anesthesia and drug abuse and may have utility for understanding drug interactions.