RESUMEN
Cisplatin, a platinum-based anticancer drug used frequently in cancer treatment, causes skeletal muscle atrophy. It was predicted that the proteolytic pathway is enhanced as the mechanism of this atrophy. Therefore, we investigated whether a platinum-based anticancer drug affects the expression of the major proteins of skeletal muscle, myosin heavy chain (MyHC). Mice were injected with cisplatin or oxaliplatin for four consecutive days. C2C12 myotubes were treated using cisplatin and oxaliplatin. Administration of platinum-based anticancer drug reduced quadriceps mass and muscle strength compared to the control group. Protein levels of all MyHC isoforms were reduced in the platinum-based anticancer drug groups. However, only Myh2 (MyHC-IIa) gene expression in skeletal muscle of mice treated with platinum-based anticancer drugs was found to be reduced. Treatment of C2C12 myotubes with platinum-based anticancer drugs reduced the protein levels of all MyHCs, and treatment with the proteasome inhibitor MG-132 restored this reduction. The expression of Mef2c, which was predicted to act upstream of Myh2, was reduced in the skeletal muscle of mice treated systemically with platinum-based anticancer drug. Degradation of skeletal muscle MyHCs by proteasomes may be a factor that plays an important role in muscle mass loss in platinum-based anticancer drug-induced muscle atrophy.
Asunto(s)
Antineoplásicos , Cadenas Pesadas de Miosina , Ratones , Animales , Cadenas Pesadas de Miosina/genética , Cadenas Pesadas de Miosina/metabolismo , Regulación hacia Abajo , Cisplatino , Platino (Metal)/metabolismo , Oxaliplatino , Músculo Esquelético/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Antineoplásicos/farmacología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Atrofia/metabolismoRESUMEN
BACKGROUND AND AIM: Although liver diseases, including non-alcoholic steatohepatitis, are associated with skeletal muscle atrophy, the mechanism behind their association has not been fully elucidated. In this study, the effects of aging and non-alcoholic steatohepatitis on the skeletal muscle, and the interaction between the liver and muscle were investigated using a diet-induced non-alcoholic steatohepatitis model in senescence-accelerated mice. METHODS: A total of four groups of senescence-accelerated mice and the control mice were fed either a non-alcoholic steatohepatitis-inducing or control diet, and their livers and skeletal muscles were removed for examinations. RESULTS: In the senescence-accelerated/non-alcoholic steatohepatitis group, serum level of alanine aminotransferase was markedly elevated and histopathology of non-alcoholic steatohepatitis was significant. Skeletal muscles were also markedly atrophied. The expression of the ubiquitin ligase Murf1 in the muscle was significantly increased with muscle atrophy, while that of Tnfa was not significantly different. In contrast, the hepatic Tnfa expression and serum TNF-α levels were significantly increased in the senescence-accelerated/non-alcoholic steatohepatitis group. These results suggest that liver-derived TNF-α might promote muscle atrophy associated with steatohepatitis and aging through Murf-1. The metabolomic analysis of skeletal muscle indicated higher spermidine and lower tryptophan levels in the steatohepatitis-diet group. CONCLUSIONS: The findings of this study revealed an aspect of liver-muscle interaction, which might be important in developing treatments for sarcopenia associated with liver diseases.
Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Sarcopenia , Animales , Ratones , Modelos Animales de Enfermedad , Hígado/metabolismo , Hígado/patología , Ratones Endogámicos C57BL , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Sarcopenia/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Cholangiocarcinoma is the second most common primary cancer of the liver and has a poor prognosis. Various animal models, including carcinogen-induced and genetically engineered rodent models, have been established to clarify the mechanisms underlying cholangiocarcinoma development. In the present study, we developed a novel mouse model of malignant lesions in the biliary ducts induced by the administration of the carcinogen azoxymethane to obese C57BLKS/J-db/db mice. A histopathological analysis revealed that the biliary tract lesions in the liver appeared to be an intrahepatic cholangiocarcinoma with higher tumor incidence, shorter experimental duration, and a markedly increased incidence in obese mice. Molecular markers analyzed using a microarray and a qPCR indicated that the cancerous lesions originated from the cholangiocytes and developed in the inflamed livers. These findings indicated that this is a novel mouse model of intrahepatic cholangiocarcinoma in the context of steatohepatitis. This model can be used to provide a better understanding of the pathogenic mechanisms of cholangiocarcinoma and to develop novel therapeutic strategies for this malignancy.
Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Ratones , Animales , Conductos Biliares Intrahepáticos/patología , Azoximetano/toxicidad , Neoplasias de los Conductos Biliares/inducido químicamente , Neoplasias de los Conductos Biliares/patología , Colangiocarcinoma/inducido químicamente , Colangiocarcinoma/patología , Carcinógenos/toxicidadRESUMEN
Previous studies have shown that phosphorylation of the retinoid X receptor-α (RXRα) is associated with the development of hepatocellular carcinoma (HCC). However, these findings were revealed using HCC cell lines that express phosphorylated-RXRα (p-RXRα) proteins; therefore, it remains unclear whether p-RXRα affects hepatocarcinogenesis in vivo. Therefore, to investigate the biological function of p-RXRα in vivo, we developed a doxycycline-inducible ES cell line and transgenic mouse, both of which overexpress the phosphomimetic mutant form of RXRα, T82D/S260D, in a doxycycline-dependent manner. We found that the development of liver tumors, especially high-grade adenoma and HCC, was enhanced in diethylnitrosamine (DEN)-treated T82D/S260D-inducible mice. Moreover, the increased incidence of liver tumors in the transgenic mice was attributable to the promotion of cell cycle progression. Interestingly, the expression of ß-catenin protein and its target gene cyclin D1 was elevated in the liver tumors of DEN-treated T82D/S260D-inducible mice, concurrent with increased cytoplasmic and nuclear ß-catenin protein expression, indicating its stabilization and transcriptional activation. These results indicate that p-RXRα promotes DEN-induced hepatocarcinogenesis in mice through the activation of the ß-catenin signaling pathway, suggesting that p-RXRα may serve as a possible therapeutic target for HCC.
Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Carcinogénesis/inducido químicamente , Carcinogénesis/genética , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Dietilnitrosamina/toxicidad , Doxiciclina , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Ratones , Ratones Transgénicos , Receptor alfa X Retinoide/genética , Receptor alfa X Retinoide/metabolismo , Receptores X Retinoide , Transducción de Señal , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
BACKGROUND: Chimpi, the dried peel of Citrus unshiu or Citrus reticulata, has various pharmacological effects. Chimpi extract was recently shown to affect the skin, including its inhibitory effect against atopic dermatitis. In this study, we analyzed the effects of Chimpi extract on the functional molecule aquaporin-3 (AQP3), which is involved in water transport and cell migration in the skin. METHODS AND RESULTS: Chimpi extract was added to HaCaT human skin keratinocytes, and the AQP3 expression level was analyzed. A wound healing assay was performed to evaluate the effect of Chimpi extract on cell migration. The components of Chimpi extract and fractions obtained by liquid-liquid distribution studies were added to HaCaT cells, and AQP3 expression was analyzed. Chimpi extract significantly increased AQP3 expression in HaCaT cells at both the mRNA and protein levels. Immunocytochemical staining revealed that Chimpi extract also promoted the transfer of AQP3 to the cell membrane. Furthermore, Chimpi extract enhanced cell migration. Hesperidin, narirutin, and nobiletin did not increase AQP3 levels. Although the components contained in the fractions obtained from the chloroform, butanol, and water layer increased AQP3, the active components could not be identified. CONCLUSIONS: These results reveal that Chimpi extract may increase AQP3 levels in keratinocytes and increase the dermal water content. Therefore, Chimpi extract may be effective for the management of dry skin.
Asunto(s)
Acuaporina 3 , Citrus , Humanos , Acuaporina 3/genética , Acuaporina 3/metabolismo , Células Cultivadas , Queratinocitos/metabolismo , Agua/metabolismo , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismoRESUMEN
We have previously reported that swellings caused by haptens, such as 2,4,6-trinitrochlorobenzene (TNCB), may be associated with the extracellular signal-regulated kinase (ERK)-induced proliferation pathway. However, the involvement of the Spred/Sprouty family as critical negative regulators of the Ras/Raf/ERK signaling pathway at disease sites is not well-established. Thus, in the present study, the effects of hapten-challenge on the expression levels of genes and proteins associated with the Spred/Sprouty family in the ear of mice were investigated. The activation of ERK and epidermal growth factor receptor (EGFR) tyrosine kinase was inhibited by their selective inhibitors, namely, U0126 and PD168393, respectively. Twenty-four hours after the final challenge by the haptens TNCB, 2,4-dinitrofluorobenzene, or oxazolone, ear thickness was augmented by challenge with all haptens and the gene expression levels of Spred1, Spred2, Sprouty1, and Sprouty2 in swelling induced by all haptens were significantly decreased. Furthermore, Spred2, Sprouty1, and Sprouty2 genes were decreased in the epidermis and dermis of the TNCB-challenged ear. In conclusion, it is possible that the mechanism of hapten-challenge-induced skin thickening involves not only the enhancement of cell proliferative functions via the activation of ERK by EGFR tyrosine kinase activation but also the decreases expression of Spred/Sprouty family members.
Asunto(s)
Dermatitis por Contacto , Proteínas Represoras , Animales , Receptores ErbB/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Ratones , Cloruro de Picrilo , Proteínas Tirosina Quinasas , Proteínas Represoras/metabolismoRESUMEN
Cisplatin is a chemotherapy drug used to treat a variety of cancers. Muscle loss in cancer patients is associated with increased cancer-related mortality. Previously, we suggested that cisplatin administration increases the atrophic gene expressions of ubiquitin E3 ligases, such as atrogin-1 and muscle RING finger-1 (MuRF1), which may lead to muscle atrophy. In this study, C57BL/6J mice were treated with cisplatin (3 mg/kg, intraperitoneally) or saline for 4 consecutive days. Twenty-four hours after the final injection of cisplatin, quadriceps muscles were removed from the mice. The gene expression of Psma and Psmb, which comprise the 20S proteasome, was upregulated by cisplatin administration in the quadriceps muscle of mouse. Systemic administration of cisplatin significantly reduced not only the quadriceps muscle mass but also the diameter of the myofibers. In addition, bortezomib (0.125 mg/kg, intraperitoneally) was administered 30 min before each cisplatin treatment. The co-administration of bortezomib, a proteasome inhibitor, significantly recovered the reductions in the mass of quadriceps and myofiber diameter, although it did not recover the decline in the forelimb and forepaw strength induced by cisplatin. Increased 20S proteasome abundance may play a significant role in the development of cisplatin-induced muscle atrophy. During cisplatin-induced skeletal muscle atrophy, different mechanisms may be involved between loss of muscle mass and strength. In addition, it is suggested that bortezomib has essentially no effect on cisplatin-induced muscle atrophy.
Asunto(s)
Cisplatino , Complejo de la Endopetidasa Proteasomal , Animales , Bortezomib , Ratones , Ratones Endogámicos C57BL , Atrofia Muscular/inducido químicamente , Atrofia Muscular/tratamiento farmacológicoRESUMEN
PURPOSE: Extracellular acidification is a major component of tissue inflammation, including airway inflammation. The extracellular proton-sensing mechanisms are inherent in various cells including airway structural cells, although their physiological and pathophysiological roles in bronchial smooth muscles (BSMs) are not fully understood. In the present study, to explore the functional role of extracellular acidification on the BSM contraction, the isolated mouse BSMs were exposed to acidic pH under contractile stimulation. METHODS AND RESULTS: The RT-PCR analyses revealed that the proton-sensing G protein-coupled receptors were expressed both in mouse BSMs and cultured human BSM cells. In the mouse BSMs, change in the extracellular pH from 8.0 to 6.8 caused an augmentation of contraction induced by acetylcholine. Interestingly, the acidic pH-induced BSM hyper-contraction was further augmented in the mice that were sensitized and repeatedly challenged with ovalbumin antigen. In this animal model of asthma, upregulations of G protein-coupled receptor 68 (GPR68) and GPR65, that were believed to be coupled with Gq and Gs proteins respectively, were observed, indicating that the acidic pH could cause hyper-contraction probably via an activation of GPR68. However, psychosine, a putative antagonist for GPR68, failed to block the acidic pH-induced responses. CONCLUSION: These findings suggest that extracellular acidification contributes to the airway hyperresponsiveness, a characteristic feature of bronchial asthma. Further studies are required to identify the receptor(s) responsible for sensing extracellular protons in BSM cells.
Asunto(s)
Asma , Hiperreactividad Bronquial , Acetilcolina/efectos adversos , Acetilcolina/metabolismo , Animales , Bronquios , Hiperreactividad Bronquial/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Inflamación/metabolismo , Ratones , Ratones Endogámicos BALB C , Músculo Liso/metabolismo , Ovalbúmina , Protones , Psicosina/efectos adversos , Psicosina/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMEN
In the present study, we demonstrated that there is a direct relationship between scratching behaviors induced by itch and functional changes in the brain reward system. Using a conditional place preference test, the rewarding effect was clearly evoked by scratching under both acute and chronic itch stimuli. The induction of ΔFosB, a member of the Fos family of transcription factors, was observed in dopamine transporter (DAT)-positive dopamine neurons in the ventral tegmental area (VTA) of mice suffering from a chronic itch sensation. Based on a cellular analysis of scratching-activated neurons, these neurons highly expressed tyrosine hydroxylase (TH) and DAT genes in the VTA. Furthermore, in an in vivo microdialysis study, the levels of extracellular dopamine in the nucleus accumbens (NAcc) were significantly increased by transient scratching behaviors. To specifically suppress the mesolimbic dopaminergic pathway using pharmacogenetics, we used the TH-cre/hM4Di mice. Pharmacogenetic suppression of mesolimbic dopaminergic neurons significantly decreased scratching behaviors. Under the itch condition with scratching behaviors restricted by an Elizabethan collar, the induction of ΔFosB was found mostly in corticotropin-releasing hormone (CRH)-containing neurons of the hypothalamic paraventricular nucleus (PVN). These findings suggest that repetitive abnormal scratching behaviors under acute and chronic itch stimuli may activate mesolimbic dopamine neurons along with pleasant emotions, while the restriction of such scratching behaviors may initially induce the activation of PVN-CRH neurons associated with stress.
Asunto(s)
Prurito/fisiopatología , Prurito/psicología , Recompensa , Área Tegmental Ventral/fisiopatología , Enfermedad Aguda , Animales , Conducta Animal/fisiología , Enfermedad Crónica , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/genética , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Neuronas Dopaminérgicas/metabolismo , Expresión Génica , Histamina/administración & dosificación , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Núcleo Accumbens/fisiopatología , Pruebas de Farmacogenómica , Cloruro de Picrilo/administración & dosificación , Prurito/genética , Tirosina 3-Monooxigenasa/genéticaRESUMEN
Bronchomotor tone is regulated by contraction and relaxation of airway smooth muscle (ASM). A weakened ASM relaxation might be a cause of airway hyperresponsiveness (AHR), a characteristic feature of bronchial asthma. Pituitary adenylyl cyclase-activating polypeptide (PACAP) is known as a mediator that causes ASM relaxation. To date, whether or not the PACAP responsiveness is changed in asthmatic ASM is unknown. The current study examined the hypothesis that relaxation induced by PACAP is reduced in bronchial smooth muscle (BSM) of allergic asthma. The ovalbumin (OA)-sensitized mice were repeatedly challenged with aerosolized OA to induce asthmatic reaction. Twenty-four hours after the last antigen challenge, the main bronchial smooth muscle (BSM) tissues were isolated. Tension study showed a BSM hyperresponsiveness to acetylcholine in the OA-challenged mice. Both quantitative RT-PCR and immunoblot analyses revealed a significant decrease in PAC1 receptor expression in BSMs of the diseased mice. Accordingly, in the antigen-challenged group, the PACAP-induced PAC1 receptor-mediated BSM relaxation was significantly attenuated, whereas the relaxation induced by vasoactive intestinal polypeptide was not changed. These findings suggest that the relaxation induced by PACAP is impaired in BSMs of experimental asthma due to a downregulation of its binding partner PAC1 receptor. Impaired BSM responsiveness to PACAP might contribute to the AHR in asthma.
Asunto(s)
Asma/metabolismo , Bronquios/metabolismo , Músculo Liso/metabolismo , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/metabolismo , Tensoactivos/metabolismo , Animales , Hiperreactividad Bronquial/metabolismo , Ratones , Relajación Muscular/efectos de los fármacos , Relajación Muscular/fisiología , Hipersensibilidad Respiratoria/metabolismo , Péptido Intestinal Vasoactivo/metabolismoRESUMEN
We previously demonstrated that cisplatin administration in mice induces muscle atrophy and an increase in the expression of two muscle-specific ubiquitin E3 ligase genes, muscle ring finger protein 1 (MuRF1), and atrophy gene-1 (atrogin-1), in skeletal muscle. Ubiquitination serves as a degradation signal in both the ubiquitin-proteasome and selective autophagy pathways. In the present study, we investigated changes in the expression of ubiquitin and ubiquitinated proteins and their degradation pathways. Ubiquitin and ubiquitinated protein levels were increased by cisplatin compared with those in the vehicle and dietary restriction (DR) groups. To quantify the levels of ubiquitin and ubiquitinated proteins, we conducted a dot blot assay using an anti-ubiquitin antibody. The expression of ubiquitin was also significantly increased by cisplatin compared with that in the vehicle and DR groups. Since the ubiquitin proteins were upregulated by cisplatin, we measured the mRNA levels of the ubiquitin genes: Ubb, Ubc, Rps27a, and Uba52. All these four genes were increased by cisplatin administration compared with those in both the vehicle-treated and DR groups in quadriceps muscle tissue. The anti-ubiquitin antibody-sensitive bands increased when C2C12 myotubes were treated with cisplatin. Furthermore, MG-132 (26 s proteasome inhibitor), but not bafilomycin A1 (autophagy inhibitor), caused a further increase in expression. In conclusion, ubiquitin and ubiquitinated proteins are upregulated in cisplatin-induced muscle atrophy. Cisplatin-induced ubiquitinated proteins are degraded by the 26 s proteasome pathway.
Asunto(s)
Cisplatino/toxicidad , Regulación de la Expresión Génica/efectos de los fármacos , Atrofia Muscular/inducido químicamente , Proteínas Ubiquitinadas/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Animales , Antineoplásicos/toxicidad , Línea Celular , Regulación de la Expresión Génica/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Mioblastos/efectos de los fármacos , Proteínas Ubiquitinadas/genéticaRESUMEN
In allergic bronchial asthma, an increased smooth muscle contractility of the airways is one of the causes of the airway hyperresponsiveness (AHR). Increasing evidence also suggests a possible involvement of microRNAs (miRNAs) in airway diseases, including asthma, although their roles in function and pathology largely unknown. The current study aimed to determine the role of a miRNA, miR-140-3p, in the control of protein expression of CD38, which is believed to regulate the contraction of smooth muscles, including the airways. In bronchial smooth muscles (BSMs) of the mice that were actively sensitized and repeatedly challenged with ovalbumin antigen, an upregulation of CD38 protein concurrently with a significant reduction of miR-140-3p was observed. In cultured human BSM cells (hBSMCs), transfection with a synthetic miR-140-3p inhibitor caused an increase in CD38 protein, indicating that its basal protein expression is regulated by endogenous miR-140-3p. Treatment of the hBSMCs with interleukin-13 (IL-13), an asthma-related cytokine, caused both an upregulation of CD38 protein and a downregulation of miR-140-3p. Transfection of the hBSMCs with miR-140-3p mimic inhibited the CD38 protein upregulation induced by IL-13. On the other hand, neither a CD38 product cyclic ADP-ribose (cADPR) nor its antagonist 8-bromo-cADPR had an effect on the BSM contraction even in the antigen-challenged mice. Taken together, the current findings suggest that the downregulation of miR-140-3p induced by IL-13 might cause an upregulation of CD38 protein in BSM cells of the disease, although functional and pathological roles of the upregulated CD38 are still unclear.
Asunto(s)
ADP-Ribosil Ciclasa 1/genética , Asma/genética , Bronquios/metabolismo , Hipersensibilidad/complicaciones , Glicoproteínas de Membrana/genética , MicroARNs/genética , ADP-Ribosil Ciclasa 1/metabolismo , Animales , Asma/etiología , Asma/metabolismo , Bronquios/citología , Línea Celular , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Hipersensibilidad/genética , Hipersensibilidad/metabolismo , Interleucina-13/farmacología , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Miocitos del Músculo Liso/metabolismo , Ovalbúmina/efectos adversosRESUMEN
Type 2 diabetes mellitus and its related insulin resistance are known to increase the risk of cancer. Anti-diabetic agents can improve insulin resistance and may lead to the suppression of carcinogenesis. This study aimed to investigate the preventive effects of the alpha-glucosidase inhibitor voglibose on the development of azoxymethane-induced colorectal pre-neoplastic lesions in obese and diabetic C57BL/KsJ-db/db mice. The direct effects of voglibose on the proliferation of colorectal cancer cells were also evaluated. Mice were injected with azoxymethane to induce colorectal pre-malignancy and were then administered drinking water with or without voglibose. At the end of the study, the administration of voglibose significantly suppressed the development of colorectal neoplastic lesions. In voglibose-treated mice, serum glucose levels, oxidative stress, as well as mRNA expression of the insulin-like growth factor-1 in the colon mucosa, were reduced. The proliferation of human colorectal cancer cells was not altered by voglibose. These results suggested that voglibose suppressed colorectal carcinogenesis in a diabetes- and obesity-related colorectal cancer model, presumably by improving inflammation via the reduction of oxidative stress and suppressing of the insulin-like growth factor/insulin-like growth factor-1 receptor axis in the colonic mucosa.
Asunto(s)
Neoplasias del Colon/etiología , Neoplasias del Colon/patología , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Inositol/análogos & derivados , Animales , Antioxidantes/química , Antioxidantes/farmacología , Azoximetano/efectos adversos , Biomarcadores , Biopsia , Proliferación Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animales de Enfermedad , Humanos , Mediadores de Inflamación , Inositol/química , Inositol/farmacología , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , FN-kappa B/metabolismo , Obesidad/complicaciones , Obesidad/metabolismo , Estrés Oxidativo/efectos de los fármacos , Lesiones PrecancerosasRESUMEN
It has recently been exhibited that Rac1 expression is increased in the bronchial tissue of a murine model with repeated antigen-challenged airway hyperresponsiveness (AHR). In the present study, the role of Rac1 in endothelin-1 (ET-1)-induced bronchial contraction and myosin light chain (MLC) phosphorylation was examined in AHR mice. Enhanced reactions in AHR mice were prevented by the Rac1 inhibitor NSC23766. These findings suggest that increased activation of Rac1 might be responsible for the enhancement of the bronchial contraction induced by ET-1 in AHR.
Asunto(s)
Hiperreactividad Bronquial/metabolismo , Broncoconstricción , Endotelina-1/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Aminoquinolinas/metabolismo , Aminoquinolinas/farmacología , Animales , Bronquios/metabolismo , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos BALB C , Músculo Liso/metabolismo , Músculo Liso/fisiopatología , Cadenas Ligeras de Miosina/química , Cadenas Ligeras de Miosina/metabolismo , Fosforilación , Pirimidinas/metabolismo , Pirimidinas/farmacologíaRESUMEN
Recently, we demonstrated that Rac1 upregulation is involved in augmented bronchial smooth muscle (BSM) contractions of antigen-challenged mice. However, change in G protein-coupled receptor (GPCR)-induced Rac1 activation remains unknown in BSMs of repeatedly antigen-challenged (Chal.) mice. We here examined carbachol (CCh)-induced Rac1 activation in BSMs of Chal. mice. Gene expression levels of both Rac1 and Rac-guanine nucleotide exchange factors (GEFs), such as Tiam1 and Trio, were increased in BSMs of Chal. mice. Furthermore, CCh-induced Rac1 activation was inhibited by pretreatment with Rac1-GEF inhibitor NSC23766 and Rac1 inhibitor EHT1864 in BSMs of sensitized-control (S.C.) and Chal. mice. Compared with S.C. mice, CCh-induced Rac1 activation was increased in BSMs of Chal. mice. In conclusion, we reported that increased CCh-induced Rac1 activation via Tiam1 and Trio upregulation, in addition to upregulate Rac1, may be involved in increased CCh-induced BSM contractions in Chal. mice.
Asunto(s)
Bronquios/fisiología , Factores de Intercambio de Guanina Nucleótido/fisiología , Contracción Muscular/fisiología , Músculo Liso/fisiología , Neuropéptidos/fisiología , Fosfoproteínas/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Proteína 1 de Invasión e Inducción de Metástasis del Linfoma-T/fisiología , Proteína de Unión al GTP rac1/fisiología , Aminoquinolinas/farmacología , Animales , Antígenos , Asma/genética , Asma/fisiopatología , Bronquios/efectos de los fármacos , Carbacol , Factores de Intercambio de Guanina Nucleótido/genética , Masculino , Ratones Endogámicos BALB C , Agonistas Muscarínicos , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Neuropéptidos/antagonistas & inhibidores , Neuropéptidos/genética , Ovalbúmina , Fosfoproteínas/genética , Proteínas Serina-Treonina Quinasas/genética , Pirimidinas/farmacología , Pironas/farmacología , Quinolinas/farmacología , Proteína 1 de Invasión e Inducción de Metástasis del Linfoma-T/genética , Regulación hacia Arriba , Proteína de Unión al GTP rac1/antagonistas & inhibidores , Proteína de Unión al GTP rac1/genéticaRESUMEN
Dexamethasone for antiemetic therapy is typically administered with anticancer drugs such as cisplatin. We previously reported that cisplatin upregulates the muscle-specific E3 ubiquitin ligase genes, namely muscle ring-finger protein 1 (MuRF1) and atrophy gene-1 (atrogin-1), and promotes muscle atrophy in mice. It is well known that dexamethasone causes upregulation of MuRF1 and Atrogin-1 expression in skeletal muscles. Although it is speculated that a combination of dexamethasone and cisplatin worsens muscle atrophy, there are no reports based on research. We thereby investigated the effects of cisplatin and dexamethasone, alone or in combination, on the expression of MuRF1 and Atrogin-1 in murine skeletal muscles and C2C12 myotubes. Mice were intraperitoneally injected with cisplatin or the vehicle control once daily for 4 days. Dexamethasone or the vehicle control was subcutaneously administered 30 minutes prior to the administration of cisplatin. Dexamethasone enhanced MuRF1 and Atrogin-1 gene expression upregulated by cisplatin in murine quadriceps muscles and C2C12 myotubes. Cisplatin-caused upregulation of myostatin and downregulation of IGF-1 gene expression were also enhanced by co-administration of dexamethasone in murine quadriceps muscles and C2C12 myotubes. This study shows that the combination treatment of cisplatin and dexamethasone exacerbated muscle atrophy in mice. Therefore, this treatment regimen might exacerbate muscle atrophy in cancer patients.
Asunto(s)
Cisplatino/efectos adversos , Dexametasona/efectos adversos , Atrofia Muscular/inducido químicamente , Animales , Peso Corporal/efectos de los fármacos , Sinergismo Farmacológico , Regulación de la Expresión Génica/efectos de los fármacos , Ratones , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patología , Proteínas Musculares/genética , Atrofia Muscular/genética , Atrofia Muscular/patología , Proteínas Ligasas SKP Cullina F-box/genética , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Xeroderma is a frequent complication in diabetic patients. In this study, we investigated the mechanism underlying the onset of diabetic xeroderma, focusing on aquaporin-3 (AQP3), which plays an important role in water transport in the skin. Dermal water content in diabetic mice was significantly lower than that in control mice. The expression level of AQP3 in the skin was significantly lower in diabetic mice than in control mice. One week after streptozotocin (STZ) treatment, despite their increased blood glucose levels, mice showed no changes in the expression levels of AQP3, Bmal1, Clock, and D site-binding protein (Dbp) in the skin and 8-hydroxydeoxyguanosine (8-OHdG) in the urine. In contrast, two weeks after STZ treatment, mice showed increases in the blood glucose level, decreases in AQP3, Bmal1, Clock, and Dbp levels, and increases in the urinary levels of 8-OHdG. The results of this study suggest that skin AQP3 expression decreases in diabetes, which may limit water transport from the vessel side to the corneum side, causing dry skin. In addition, in diabetic mice, increased oxidative stress triggered decreases in the expression levels of Bmal1 and Clock in the skin, thereby inhibiting the transcription of Aqp3 by Dbp, which resulted in decreased AQP3 expression.
Asunto(s)
Acuaporina 3/metabolismo , Diabetes Mellitus Experimental/complicaciones , Ictiosis/etiología , Agua/metabolismo , Animales , Acuaporina 3/análisis , Glucemia/análisis , Glucemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Modelos Animales de Enfermedad , Ingestión de Líquidos , Ictiosis/metabolismo , Ictiosis/patología , Masculino , Ratones , Ratones Pelados , Piel/metabolismo , Piel/patología , Estreptozocina , Agua/análisisRESUMEN
Progranulin (PGRN) is a growth factor with multiple biological functions and has been suggested as an endogenous inhibitor of Tumor necrosis factor-α (TNF-α)-mediated signaling. TNF-α is believed to be one of the important mediators of the pathogenesis of asthma, including airway hyperresponsiveness (AHR). In the present study, effects of recombinant PGRN on TNF-α-mediated signaling and antigen-induced hypercontractility were examined in bronchial smooth muscles (BSMs) both in vitro and in vivo. Cultured human BSM cells (hBSMCs) and male BALB/c mice were used. The mice were sensitized and repeatedly challenged with ovalbumin antigen. Animals also received intranasal administrations of recombinant PGRN into the airways 1 h before each antigen inhalation. In hBSMCs, PGRN inhibited both the degradation of IκB-α (an index of NF-κB activation) and the upregulation of RhoA (a contractile machinery-associated protein that contributes to the BSM hyperresponsiveness) induced by TNF-α, indicating that PGRN has an ability to inhibit TNF-α-mediated signaling also in the BSM cells. In BSMs of the repeatedly antigen-challenged mice, an augmented contractile responsiveness to acetylcholine with an upregulation of RhoA was observed: both the events were ameliorated by pretreatments with PGRN intranasally. Interestingly, a significant decrease in PGRN expression was found in the airways of the repeatedly antigen-challenged mice rather than those of control animals. In conclusion, exogenously applied PGRN into the airways ameliorated the antigen-induced BSM hyperresponsiveness, probably by blocking TNF-α-mediated response. Increasing PGRN levels might be a promising therapeutic for AHR in allergic asthma.
Asunto(s)
Asma/fisiopatología , Bronquios/fisiopatología , Hiperreactividad Bronquial/prevención & control , Péptidos y Proteínas de Señalización Intercelular/administración & dosificación , Músculo Liso/patología , Proteínas Recombinantes/administración & dosificación , Hipersensibilidad Respiratoria/prevención & control , Administración Intranasal , Animales , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/metabolismo , Células Cultivadas , Granulinas , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Músculo Liso/metabolismo , Progranulinas , Hipersensibilidad Respiratoria/etiología , Hipersensibilidad Respiratoria/metabolismo , Transducción de SeñalRESUMEN
The process of skin wound healing involves the following three steps: inflammation, tissue formation and tissue remodelling. These optimal steps are required for the development of normal wound healing. Recent reports demonstrated that inflammasomes are involved in the innate immune response. In the present study, we examined whether the activation of inflammasomes affects the process of skin wound repair. The skin wound repair model was established using wild-type (WT), NACHT, LRR and PYD domains-containing protein 3 (NALP3) knockout (KO) and ASC-KO mice. The wounds were observed every other day, and changes in wound size over time were calculated using photography. Wound repair in NALP3-KO and ASC-KO mice was significantly impaired compared with WT mice. Isoliquiritigenin, an inhibitor of NALP3, decreased the rate of wound repair in WT mice. mRNA expression of pro-inflammatory cytokines in the wound sites of NALP3-KO mice was markedly decreased compared with WT mice. Treatment with adenosine triphosphate (ATP), a ligand of NALP3, upregulated the mRNA expression of pro-inflammatory cytokines at the wound site and accelerated wound healing in the WT mice. Scratch assay revealed that ATP accelerated wound closure in mouse embryonic fibroblasts from WT mice but not from NALP3-KO mice. In conclusion, the present study demonstrated that NALP3 pathway activation is involved in wound repair, and the topical use of ATP may be useful as an effective treatment for accelerating wound healing.
Asunto(s)
Adenosina Trifosfato/administración & dosificación , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Transducción de Señal , Cicatrización de Heridas , Administración Tópica , Animales , Citocinas/metabolismo , Fibroblastos/metabolismo , Inflamasomas/metabolismo , Ligandos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Piel/metabolismo , Regulación hacia ArribaRESUMEN
Contact dermatitis is a form of delayed-type hypersensitivity characterized by localized thickening, papules, redness and vesicles of the skin. A model of contact dermatitis involving repeated challenge of a hapten is adapted to assess dermatitis as characterized by skin thickening. Recently, it was reported that neutrophils have crucial roles in contact hypersensitivity. We thus examined the involvement of CXC chemokines bearing the glutamic acid-leucine-arginine (ELR) motif ("ELR+ chemokines") and neutrophils in the ear swelling induced by 2,4,6-trinitrochlorobenzene (TNCB) challenges in the present study. Mice were sensitized by application of TNCB on their abdominal skin. They were then challenged thrice with TNCB to the ear. The CXCR2 antagonist SB225002 (9 mg/kg, i.p.) was administered before each TNCB challenge. Gene expressions and protein levels of the ELR+ chemokines CXCL1, 2 and 5 was increased markedly in mouse ear after the final TNCB challenge. In addition, we indicated that gene expression of CXCL1 was enhanced in the epidermis and dermis upon TNCB challenge. Expression of the CXCL2 gene was enhanced in the epidermis, and that of the CXCL5 gene was enhanced in the dermis. The swelling induced by TNCB challenges was significantly attenuated by SB225002. Furthermore, the increases in myeloperoxidase activity, and expression of myeloperoxidase and neutrophil elastase induced by TNCB challenge in mouse ear were inhibited by SB225002. These data suggest that ear swelling resulting from TNCB challenges might be concerned by upregulated ELR+ chemokine-induced neutrophil recruitment.