RESUMEN
Keratinocytes, the epithelial cells of the skin, reprogram their gene expression and produce immune effector molecules when exposed to environmental and endogenous triggers of inflammation. It remains unclear how keratinocytes process physiological signals generated during skin irritation and switch from a homeostatic to an inflammatory state. In this article, we show that the stress-activated protein kinase p38α is crucial for keratinocytes to prompt changes in their transcriptome upon cytokine stimulation and drive inflammation in allergen-exposed skin. p38α serves this function by phosphorylating p63, a transcription factor essential for the lineage identity and stemness of the skin epithelium. Phosphorylation by p38α alters the activity of p63 and redeploys this developmental transcription factor to a gene expression program linked to inflammation. Genetic ablation and pharmacological inhibition of p38α or the p38α-p63 target gene product MMP13 attenuate atopic dermatitis-like disease in mice. Our study reveals an epithelial molecular pathway promoting skin inflammation and actionable through treatment with topical small-molecule therapeutics.
Asunto(s)
Dermatitis Atópica , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Factores de Transcripción , Animales , Dermatitis Atópica/metabolismo , Inflamación/metabolismo , Queratinocitos/metabolismo , Ratones , Fosforilación , Factores de Transcripción/metabolismoRESUMEN
The evolutionarily conserved protein kinase p38 mediates innate resistance to environmental stress and microbial infection. Four p38 isoforms exist in mammals and may have been co-opted for new roles in adaptive immunity. Murine T cells deficient in p38α, the ubiquitously expressed p38 isoform, showed no readily apparent cell-autonomous defects while expressing elevated amounts of another isoform, p38ß. Mice with T cells simultaneously lacking p38α and p38ß displayed lymphoid atrophy and elevated Foxp3+ regulatory T cell frequencies. Double deficiency of p38α and p38ß in naïve CD4+ T cells resulted in an attenuation of MAPK-activated protein kinase (MK)-dependent mTOR signaling after T cell receptor engagement, and enhanced their differentiation into regulatory T cells under appropriate inducing conditions. Pharmacological inhibition of the p38-MK-mTOR signaling module produced similar effects, revealing potential for therapeutic applications.
Asunto(s)
Sistema de Señalización de MAP Quinasas/inmunología , Proteína Quinasa 11 Activada por Mitógenos/inmunología , Proteína Quinasa 14 Activada por Mitógenos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Animales , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/inmunología , Sistema de Señalización de MAP Quinasas/genética , Ratones , Ratones Noqueados , Proteína Quinasa 11 Activada por Mitógenos/genética , Proteína Quinasa 14 Activada por Mitógenos/genética , Receptores de Antígenos de Linfocitos T/genética , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/inmunologíaRESUMEN
The protein kinase p38α mediates cellular responses to environmental and endogenous cues that direct tissue homeostasis and immune responses. Studies of mice lacking p38α in several different cell types have demonstrated that p38α signaling is essential to maintaining the proliferation-differentiation balance in developing and steady-state tissues. The mechanisms underlying these roles involve cell-autonomous control of signaling and gene expression by p38α. In this study, we show that p38α regulates gut-associated lymphoid tissue (GALT) formation in a noncell-autonomous manner. From an investigation of mice with intestinal epithelial cell-specific deletion of the p38α gene, we find that p38α serves to limit NF-κB signaling and thereby attenuate GALT-promoting chemokine expression in the intestinal epithelium. Loss of this regulation results in GALT hyperplasia and, in some animals, mucosa-associated B cell lymphoma. These anomalies occur independently of luminal microbial stimuli and are most likely driven by direct epithelial-lymphoid interactions. Our study illustrates a novel p38α-dependent mechanism preventing excessive generation of epithelial-derived signals that drive lymphoid tissue overgrowth and malignancy.
Asunto(s)
Mucosa Intestinal/metabolismo , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , FN-kappa B/metabolismo , Ganglios Linfáticos Agregados/inmunología , Ganglios Linfáticos Agregados/metabolismo , Transducción de Señal , Animales , Línea Celular , Colitis/genética , Colitis/inmunología , Colitis/metabolismo , Colitis/patología , Colon/inmunología , Colon/metabolismo , Colon/microbiología , Colon/patología , Células Epiteliales/metabolismo , Expresión Génica , Hiperplasia , Mucosa Intestinal/inmunología , Mucosa Intestinal/microbiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Microbiota/inmunología , Proteína Quinasa 14 Activada por Mitógenos/genética , Ganglios Linfáticos Agregados/patologíaRESUMEN
Obesity and insulin resistance are associated with oxidative stress, which may be implicated in the progression of obesity-related diseases. The kinase JNK1 has emerged as a promising drug target for the treatment of obesity and type 2 diabetes. JNK1 is also a key mediator of the oxidative stress response, which can promote cell death or survival, depending on the magnitude and context of its activation. In this article, we describe a study in which the long-term effects of JNK1 inactivation on glucose homeostasis and oxidative stress in obese mice were investigated for the first time. Mice lacking JNK1 (JNK1(-/-)) were fed an obesogenic high-fat diet (HFD) for a long period. JNK1(-/-) mice fed an HFD for the long term had reduced expression of antioxidant genes in their skin, more skin oxidative damage, and increased epidermal thickness and inflammation compared with the effects in control wild-type mice. However, we also observed that the protection from obesity, adipose tissue inflammation, steatosis, and insulin resistance, conferred by JNK1 ablation, was sustained over a long period and was paralleled by decreased oxidative damage in fat and liver. We conclude that compounds targeting JNK1 activity in brain and adipose tissue, which do not accumulate in the skin, may be safer and most effective.-Becattini, B., Zani, F., Breasson, L., Sardi, C., D'Agostino, V. G., Choo, M.-K., Provenzani, A., Park, J. M., Solinas, G. JNK1 ablation in mice confers long-term metabolic protection from diet-induced obesity at the cost of moderate skin oxidative damage.
Asunto(s)
Grasas de la Dieta/efectos adversos , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Obesidad/inducido químicamente , Piel/patología , Envejecimiento , Animales , Grasas de la Dieta/administración & dosificación , Hígado Graso/inducido químicamente , Hígado Graso/metabolismo , Inflamación/metabolismo , Ratones , Ratones Noqueados , Proteína Quinasa 8 Activada por Mitógenos/genética , Estrés OxidativoRESUMEN
An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678-27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38α MAPK in ectodermal appendages using K14-cre mice (p38α(K14) mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38α, expression of amelogenin and ß4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38α in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38α functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38α MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel.
Asunto(s)
Ameloblastos/metabolismo , Esmalte Dental/metabolismo , Regulación del Desarrollo de la Expresión Génica , Incisivo/metabolismo , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Odontogénesis/genética , Ameloblastos/citología , Amelogenina/genética , Amelogenina/metabolismo , Animales , Proteína Morfogenética Ósea 2/genética , Proteína Morfogenética Ósea 2/metabolismo , Proteína Morfogenética Ósea 7/genética , Proteína Morfogenética Ósea 7/metabolismo , Diferenciación Celular , Proliferación Celular , Esmalte Dental/citología , Esmalte Dental/crecimiento & desarrollo , Incisivo/citología , Incisivo/crecimiento & desarrollo , Integrina beta4/genética , Integrina beta4/metabolismo , MAP Quinasa Quinasa 3/genética , MAP Quinasa Quinasa 3/metabolismo , MAP Quinasa Quinasa 6/genética , MAP Quinasa Quinasa 6/metabolismo , Ratones , Ratones Transgénicos , Proteína Quinasa 14 Activada por Mitógenos/genética , Transducción de Señal , Técnicas de Cultivo de Tejidos , Quinasas p21 Activadas/genética , Quinasas p21 Activadas/metabolismoRESUMEN
The epithelium of mucosal and skin surfaces serves as a permeability barrier and affords mechanisms for local immune defense. Crucial to the development and maintenance of a properly functioning epithelium is the balance of cell proliferation, differentiation, and death. Here we show that this balance depends on cross-regulatory interactions among multiple protein kinase-mediated signals and their coordinated transmission. From an investigation of conditional gene knock-out mice, we find that epithelial-specific loss of the protein kinase p38α leads to aberrant activation of TAK1, JNK, EGF receptor, and ERK in distinct microanatomical areas of the intestines and skin. Consequently, the epithelial tissues display excessive proliferation, inadequate differentiation, and sensitivity to apoptosis. These anomalies leave the tissue prone to damage and collapse at the trigger of an environmental insult. The vulnerability of p38α-deficient epithelium predicts adverse effects of long term pharmacological p38α inhibition; yet such limitations could be overcome by concomitant blockade of one or more of the dysregulated protein kinase signaling pathways.
Asunto(s)
Epitelio/enzimología , Homeostasis , Sistema de Señalización de MAP Quinasas , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Apoptosis , Diferenciación Celular , Proliferación Celular , Activación Enzimática , Células Epiteliales/enzimología , Células Epiteliales/patología , Epitelio/patología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Inflamación/enzimología , Inflamación/patología , Mucosa Intestinal/patología , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Ratones , Ratones Endogámicos C57BL , Especificidad de Órganos , Piel/patología , Ubiquitinación , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
Hematopoietic-derived cells are integral components of the tumor microenvironment and serve as critical mediators of tumor-host interactions. Host cells derived from myeloid and lymphoid lineages perform well-established functions linked to cancer development, progression, and response to therapy. It is unclear whether host erythroid cells also contribute to shaping the path that cancer can take, but emerging evidence points to this possibility. Here, we show that tumor-promoting environmental stress and tumor-induced hemodynamic changes trigger renal erythropoietin production and erythropoietin-dependent expansion of splenic erythroid cell populations in mice. These erythroid cells display molecular features indicative of an immature erythroid phenotype, such as the expression of both CD71 and TER119 and the retention of intact nuclei, and express genes encoding immune checkpoint molecules. Nucleated erythroid cells with similar properties are present in mouse and human tumor tissues. Antibody-mediated erythropoietin blockade reduces tumor-responsive erythroid cell induction and tumor growth. These findings reveal the potential of tumor-induced erythropoietin and erythroid cells as targets for cancer treatment. IMPLICATIONS: : Our study identifies erythropoietin and erythroid cells as novel players in tumor-host interactions and highlights the involvement of multiorgan signaling events in their induction in response to environmental stress and tumor growth.
Asunto(s)
Células Eritroides/metabolismo , Proteínas de Punto de Control Inmunitario/metabolismo , Animales , Diferenciación Celular , Humanos , Ratones , Transducción de SeñalRESUMEN
Cellular senescence is a major barricade on the path of cancer development, yet proteins secreted from senescent cells exert complex and often discordant effects on subsequent cancer evolution. Somatic genome alternations driving the formation of nevi and melanoma are efficient inducers of cellular senescence. Melanocyte and melanoma cell senescence is likely to come into play as a key factor affecting the course of tumorigenesis and responsiveness to therapy; little mechanistic information has been generated, however, that substantiates this idea and facilitates its clinical translation. Here, we established and characterized a model of melanoma cell senescence in which pharmacologically induced DNA damage triggered divergent ATM kinase- and STING-dependent intracellular signaling cascades and resulted in cell cycle arrest, cytomorphologic remodeling, and drastic secretome changes. Targeted proteome profiling revealed that senescent melanoma cells in this model secreted a panoply of proteins shaping the tumor immune microenvironment. CRISPR-mediated genetic ablation of the p38α and IKKß signaling modules downstream of the ATM kinase severed the link between DNA damage and this secretory phenotype without restoring proliferative capacity. A similar genetic dissection showed that loss of STING signaling prevented type I interferon induction in DNA-damaged melanoma cells but otherwise left the senescence-associated processes in our model intact. Actionable proteins secreted from senescent melanoma cells or involved in senescence-associated intracellular signaling hold potential as markers for melanoma characterization and targets for melanoma treatment.
Asunto(s)
Daño del ADN/genética , Melanoma/genética , Proteómica/métodos , Animales , Senescencia Celular , Modelos Animales de Enfermedad , Humanos , Ratones , Transducción de SeñalRESUMEN
BACKGROUND: Quiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. RESULTS: We induce chemoresistant and G0 leukemic cells by serum starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the upregulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, Tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα prior to or along with chemotherapy substantially reduces chemoresistance in primary leukemic cells ex vivo and in vivo. CONCLUSIONS: These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE-bearing mRNAs that promote chemoresistance. By disrupting this pathway, we develop an effective combination therapy against chemosurvival.
Asunto(s)
Elementos Ricos en Adenilato y Uridilato , Resistencia a Antineoplásicos , Procesamiento Postranscripcional del ARN , Tristetraprolina/metabolismo , Animales , Ciclo Celular , Células Cultivadas , Fosfatasa 1 de Especificidad Dual/genética , Fosfatasa 1 de Especificidad Dual/metabolismo , Células Hep G2 , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Células K562 , Células MCF-7 , Ratones , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteoma/genética , Proteoma/metabolismo , Células THP-1 , Transcriptoma , Tristetraprolina/genética , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
ErbB3 receptor tyrosine kinase has been shown to induce tumor progression in several types of cancer through heterodimerization with ErbB2. However, the role of ErbB3 and its ligand heregulin (HRG) in tumor metastasis remains poorly understood. In the present study, we tried to clarify their contributions to the metastasis of ErbB3-overexpressing B16-BL6 melanoma cells. Stimulation with HRG induced phosphorylation of ErbB3 and metastatic properties including MMP-9 expression, invasion, adhesion and experimental lung metastasis in vivo. These cellular responses were blocked by inhibiting the tyrosine kinase activity of EGFR with PD153035. In addition, phosphorylation of EGFR was rapidly induced by HRG, suggesting that EGFR is a possible heterodimeric counterpart of ErbB3. RNA interference demonstrated that subcutaneous tumor growth and angiogenesis was attenuated by inactivation of ErbB3 in cancer cells. Although experimental pulmonary metastasis was not affected by the knockdown of ErbB3, spontaneous metastasis was, even when primary tumors in the foot pad were amputated at a similar size. These results indicate that HRG-induced activation of ErbB3 via EGFR promotes tumor growth and metastasis of melanoma cells.
Asunto(s)
Receptores ErbB/metabolismo , Genes erbB , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Neurregulina-1/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Receptor ErbB-3/metabolismo , Animales , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Pulmonar de Lewis/patología , Línea Celular Tumoral , Proliferación Celular , Femenino , Regulación de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Immunoblotting , Inmunoprecipitación , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/patología , Masculino , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Metaloproteinasa 9 de la Matriz/metabolismo , Melanoma Experimental/metabolismo , Melanoma Experimental/patología , Ratones , Neoplasias Experimentales/irrigación sanguínea , Neovascularización Patológica/metabolismo , Fosforilación , Receptor ErbB-3/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia ArribaRESUMEN
SC-514, an inhibitor of IkappaB kinase beta (IKKbeta), blocked the TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) as well as the TNF-alpha-promoted metastasis of murine colon adenocarcinoma cells. We investigated the effect of 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (M1), a main intestinal bacterial metabolite of ginseng, on the NF-kappaB-dependent metastasis. M1 was effective in suppressing the TNF-alpha-induced activation of NF-kappaB, expression of matrix metalloprotease-9 (MMP-9), migration and invasion. The TNF-alpha-evoked increase in lung and liver metastasis of colon carcinoma was also abrogated by treatment with M1 in vitro. These results suggest that ginseng has potential to suppress inflammation-related metastasis by downregulating the NF-kappaB signaling pathway.
Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Ginsenósidos/uso terapéutico , FN-kappa B/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Animales , Movimiento Celular , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Femenino , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/secundario , Ratones , Ratones Endogámicos BALB C , Invasividad Neoplásica , Transducción de SeñalRESUMEN
The molecular circuitry directing tissue development and homeostasis is hardwired by genetic programs but may also be subject to fine-tuning or major modification by environmental conditions. It remains unclear whether such malleability is at work-particularly in tissues directly in contact with the environment-and contributes to their optimal maintenance and resilience. The protein kinase p38α is activated by physiological cues that signal tissue damage and neoplastic transformation. Here, we found that p38α phosphorylated and thereby destabilized p63, a transcription factor essential for epidermal development. Through this regulatory mechanism, p38α limited the frequency of keratinocytes with stem cell properties and tumorigenic potential. Correspondingly, epidermal loss of p38α expression or activity promoted or correlated with carcinogenesis in mouse and human skin, respectively. Genetic mouse models revealed a tumorigenic mechanism from p38α loss through p63-mediated suppression of the matrix metalloprotease MMP13. These findings illustrate a previously uncharacterized epidermal tumor-suppressive mechanism in which stress-activated signaling induces the contraction of stem cell-like keratinocyte pools.
Asunto(s)
Carcinogénesis/metabolismo , Queratinocitos/citología , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Neoplasias Cutáneas/metabolismo , Células Madre/citología , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Carcinoma de Células Escamosas/metabolismo , Diferenciación Celular , Proliferación Celular , Transformación Celular Neoplásica , Células Epidérmicas/citología , Epidermis/metabolismo , Genes Supresores de Tumor , Homeostasis , Humanos , Queratosis Actínica/metabolismo , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Fenotipo , Proteínas Quinasas/metabolismo , Transducción de SeñalRESUMEN
Dendritic cells (DCs) abundantly express diverse receptors to recognize mannans in the outer surface of Candida cell wall, and these interactions dictate the host immune responses that determine disease outcomes. C. krusei prevalence in candidiasis worldwide has increased since this pathogen has developed multidrug resistance. However, little is known how the immune system responds to C. krusei. Particularly, the molecular mechanisms of the interplay between C. krusei mannan and DCs remain to be elucidated. We investigated how C. krusei mannan affected DC responses in comparison to C. albicans, C. tropicalis and C. glabrata mannan. Our results showed that only C. krusei mannan induced massive cytokine responses in DCs, and led to apoptosis. Although C. krusei mannan-activated DCs underwent apoptosis, they were still capable of initiating Th17 response. C. krusei mannan-mediated DC apoptosis was obligated to the TLR2 and MyD88 pathway. These pathways also controlled Th1/Th17 switching possibly by virtue of the production of the polarizing cytokines IL-12 and IL-6 by the C. krusei mannan activated-DCs. Our study suggests that TLR2 and MyD88 pathway in DCs are dominant for C. krusei mannan recognition, which differs from the previous reports showing a crucial role of C-type lectin receptors in Candida mannan sensing.
Asunto(s)
Candida/patogenicidad , Células Dendríticas/inmunología , Mananos/toxicidad , Células Th17/inmunología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Candida/química , Candida/citología , Candidiasis/metabolismo , Candidiasis/microbiología , Candidiasis/patología , Pared Celular/química , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Interacciones Huésped-Patógeno , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Factor 88 de Diferenciación Mieloide/metabolismo , Células Th17/efectos de los fármacos , Células Th17/metabolismo , Receptor Toll-Like 2/metabolismoRESUMEN
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L) is a member of the TNF-alpha ligand family that selectively induces apoptosis in a variety of tumor cells. To clarify the molecular mechanism of TRAIL-induced apoptosis, we focused on transforming growth factor-beta-activated kinase 1 (TAK1) mitogen-activated protein kinase (MAPK) kinase kinase, a key regulator of the TNF-alpha-induced activation of p65/RelA and c-Jun NH2-terminal kinase/p38 MAPKs. In human cervical carcinoma HeLa cells, TRAIL induced the delayed phosphorylation of endogenous TAK1 and its activator protein TAB1 and TAB2, which contrasted to the rapid response to TNF-alpha. Specific knockdown of TAK1 using small interfering RNA (siRNA) abrogated the TRAIL-induced activation of p65 and c-Jun NH2-terminal kinase/p38 MAPKs. TRAIL-induced apoptotic signals, including caspase-8, caspase-3, caspase-7, and poly(ADP-ribose) polymerase, were enhanced by TAK1 siRNA. Flow cytometry showed that the binding of Annexin V to cell surface was also synergistically increased by TRAIL in combination with TAK1 siRNA. In addition, pretreatment of cells with 5Z-7-oxozeaenol, a selective TAK1 kinase inhibitor, enhanced the TRAIL-induced cleavage of caspases and binding of Annexin V. The TAK1-mediated antiapoptotic effects were also observed in human lung adenocarcinoma A549 cells. In contrast, TAK1-deficient mouse embryonic fibroblasts are resistant to TRAIL-induced apoptosis, and treatment of control mouse embryonic fibroblasts with 5Z-7-oxozeaenol did not drastically promote the TRAIL-induced activation of a caspase cascade. These results suggest that TAK1 plays a critical role for TRAIL-induced apoptosis, and the blockade of TAK1 kinase will improve the chances of overcoming cancer.
Asunto(s)
Apoptosis/efectos de los fármacos , Caspasas/metabolismo , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Animales , Apoptosis/genética , Sinergismo Farmacológico , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Células HeLa , Humanos , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Ratones , FN-kappa B/genética , FN-kappa B/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/metabolismo , Zearalenona/análogos & derivados , Zearalenona/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/inmunología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
The retinoic acid receptor-related orphan receptors RORα and RORγ are critical for the functions of specific subsets of T cells and innate lymphoid cells, which are key drivers of inflammatory disease in barrier tissues. Here, we investigate the anti-inflammatory potential of SR1001, a synthetic RORα/γ inverse agonist, in mouse models of atopic dermatitis and acute irritant dermatitis. Topical treatment with SR1001 reduces epidermal and dermal features of MC903-induced atopic dermatitis-like disease and suppresses the production of type 2 cytokines and other inflammatory mediators in lesional skin. In the epidermis, SR1001 treatment blocks MC903-induced expression of TSLP and reverses impaired keratinocyte differentiation. SR1001 is also effective in alleviating acute dermatitis triggered by 12-O-tetradecanoylphorbol-13-acetate. Overall, our results suggest that RORα/γ are important therapeutic targets for cutaneous inflammation and suggest topical usage of inhibitory ligands as an approach to treating skin diseases of inflammatory etiology.
Asunto(s)
Dermatitis Atópica/tratamiento farmacológico , Dermatitis Irritante/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/agonistas , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Animales , Diferenciación Celular , Citocinas/metabolismo , Dermatitis Atópica/metabolismo , Dermatitis Irritante/metabolismo , Modelos Animales de Enfermedad , Eccema/tratamiento farmacológico , Epidermis/metabolismo , Femenino , Inflamación/metabolismo , Queratinocitos/citología , Ligandos , Ratones , Ratones Endogámicos C57BL , Piel/inmunología , Sulfonamidas/química , Tiazoles/químicaRESUMEN
Post-translational redox modification of methionine residues often triggers a change in protein function. Emerging evidence points to this reversible protein modification being an important regulatory mechanism under various physiological conditions. Reduction of oxidized methionine residues is catalyzed by methionine sulfoxide reductases (Msrs). Here, we show that one of these enzymes, a selenium-containing MsrB1, is highly expressed in immune-activated macrophages and contributes to shaping cellular and organismal immune responses. In particular, lipopolysaccharide (LPS) induces expression of MsrB1, but not other Msrs. Genetic ablation of MsrB1 did not preclude LPS-induced intracellular signaling in macrophages, but resulted in attenuated induction of anti-inflammatory cytokines, such as interleukin (IL)-10 and the IL-1 receptor antagonist. This anomaly was associated with excessive pro-inflammatory cytokine production as well as an increase in acute tissue inflammation in mice. Together, our findings suggest that MsrB1 controls immune responses by promoting anti-inflammatory cytokine expression in macrophages. MsrB1-dependent reduction of oxidized methionine in proteins may be a heretofore unrecognized regulatory event underlying immunity and inflammatory disease, and a novel target for clinical applications.
Asunto(s)
Lipopolisacáridos/efectos adversos , Macrófagos/efectos de los fármacos , Metionina Sulfóxido Reductasas/metabolismo , Ésteres del Forbol/efectos adversos , Animales , Células Cultivadas , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Proteína Antagonista del Receptor de Interleucina 1/genética , Interleucina-10/genética , Macrófagos/citología , Macrófagos/metabolismo , Metionina Sulfóxido Reductasas/genética , Ratones , Transducción de Señal , Regulación hacia ArribaRESUMEN
The spores of pathogenic bacteria are involved in host entry and the initial encounter with the host immune system. How bacterial spores interact with host immunity, however, remains poorly understood. Here, we show that the spores of Bacillus anthracis (BA), the etiologic agent of anthrax, possess an intrinsic ability to induce host immune responses. This immunostimulatory activity is attributable to high amounts of RNA present in the spore surface layer. RNA-sensing TLRs, TLR7, and TLR13 in mice and their human counterparts, are responsible for detecting and triggering the host cell response to BA spores, whereas TLR2 mediates the sensing of vegetative BA. BA spores, but not vegetative BA, induce type I IFN (IFN-I) production. Although TLR signaling in itself affords protection against BA, spore RNA-induced IFN-I signaling is disruptive to BA clearance. Our study suggests a role for bacterial spore-associated RNA in microbial pathogenesis and illustrates a little known aspect of interactions between the host and spore-forming bacteria.
Asunto(s)
ARN Bacteriano/inmunología , Esporas Bacterianas/inmunología , Receptores Toll-Like/fisiología , Animales , Bacillus anthracis/inmunología , Regulación de la Expresión Génica/fisiología , Interacciones Huésped-Patógeno/inmunología , Humanos , Ratones , Esporas Bacterianas/genéticaRESUMEN
Most herbal medicines that are orally administrated have been known to be metabolized before they are absorbed from the gastrointestinal tract. We, therefore, examined the effects of 20(S)-ginsenosides Rb1, Rg1 and Rg3, the three most commonly studied ginsenosides in the central nervous system, and their main metabolites on NMDA receptors using fura-2-based digital imaging and perforated whole-cell patch-clamp techniques. Among the nine ginsenosides tested, 20(S)-ginsenoside Rh2 (20(S)-Rh2) along with 20(S)-ginsenoside Rg3 (20(S)-Rg3) produced the highest inhibitory effect in cultured hippocampal neurons. Although 20(S)-Rg3 and 20(S)-Rh2 selectively targeted NMDA receptors with similar potency, they produced additive effects and seemed to modulate different NMDA receptor regulatory sites. As a competitive antagonist, 20(S)-Rh2 seems to inhibit the receptor via its interaction with polyamine-binding sites, and 20(S)-Rg3 does so using glycine-binding sites. Therefore, these results suggest that the treatment of 20(S)-Rh2, a newly identified active ingredient of ginseng, might be a novel preventive candidate in treating neurodegenerative disorders.
Asunto(s)
Ginsenósidos/farmacología , Neuronas/efectos de los fármacos , Panax/química , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Animales , Sitios de Unión , Calcio/metabolismo , Células Cultivadas , Relación Dosis-Respuesta a Droga , Feto , Ginsenósidos/química , Hipocampo , Potenciales de la Membrana/efectos de los fármacos , Estructura Molecular , N-Metilaspartato/farmacología , Neuronas/citología , Neuronas/fisiología , Poliaminas/metabolismo , Poliaminas/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/fisiología , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
PURPOSE: To investigate the clinical significance of bilateral temporal hypometabolism (BTH) for patients with mesial temporal lobe epilepsy (MTLE) by using statistical parametric mapping (SPM). METHODS: Interictal 18F-FDG PET scans were performed for 29 patients with surgically treated MTLE. Clinical data, interictal epileptiform discharges (IEDs), ictal scalp EEG and intracarotid amobarbital test (IAT) were analyzed. To assess an 18F-FDG PET image, an SPM analysis as well as visual interpretation were applied. RESULTS: In 9 of 29 patients, the 18F-FDG PET scan revealed BTH by the SPM analysis, while only 3 patients showed BTH by the visual assessment. When the patients were classified into the unilateral temporal hypometabolism (UTH) and BTH groups based on the SPM results, bitemporal IEDs occurred significantly more frequently in the BTH group than in the UTH group (66.7% versus 22.2%). Bilateral independent seizure onset seen on the scalp EEG and bitemporal epilepsy were present only in the BTH group. Lateralized ictal onset was present less frequently in the BTH group than in the UTH group (44.4% versus 83.3%). There was no statistically significant difference in age at onset, duration of epilepsy, generalized seizure, history of febrile convulsion and CNS infection, lateralization throughout the whole tracing, lateralization on the IAT test, and surgical outcome between the UTH and BTH groups. CONCLUSION: Bilaterality of the EEG findings correlated with BTH on 18F-FDG PET by the SPM method. Our results suggest that analysis of 18F-FDG PET by using SPM may have a role in predicting those patients with bitemporal excitability or bitemporal independent epileptogenicity, and these patients should be monitored carefully.
Asunto(s)
Electroencefalografía , Epilepsia del Lóbulo Temporal/metabolismo , Procesamiento de Imagen Asistido por Computador , Tomografía de Emisión de Positrones/métodos , Adolescente , Adulto , Amobarbital , Lobectomía Temporal Anterior , Niño , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Memoria , Resultado del TratamientoRESUMEN
We investigated the influence of TNF-alpha on the metastasis of cancer cells. Treatment of cultured colon 26 cells with TNF-alpha enhanced metastatic properties including production of MMP-9, adhesion, migration and invasion. Cells treated with TNF-alpha in vitro showed marked potential to metastasize to the lung and liver in vivo. U0126, an inhibitor of MEK1/2, inhibited the TNF-alpha-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and the metastatic properties in vitro without affecting cell proliferation. In addition, pretreatment with U0126 in vitro completely abrogated the increased lung metastasis of TNF-alpha-treated cells. These results indicate that TNF-alpha-induced activation of cancer cells through the ERK pathway is sufficient for the enhanced metastatic potential of colon 26 cells.