RESUMO
Aging is a factor associated with poor prognosis in glioblastoma (GBM). It is therefore important to understand the molecular features of aging contributing to GBM morbidity. TP73-AS1 is a long noncoding RNA (lncRNA) over expressed in GBM tumors shown to promote resistance to the chemotherapeutic temozolomide (TMZ), and tumor aggressiveness. How the expression of TP73-AS1 is regulated is not known, nor is it known if its expression is associated with aging. By analyzing transcriptional data obtained from natural and pathological aging brain, we found that the expression of TP73-AS1 is high in pathological and naturally aging brains. YY1 physically associates with the promoter of TP73-AS1 and we found that along with TP73-AS1, YY1 is induced by TMZ. We found that the TP73-AS1 promoter is activated by TMZ, and by YY1 over expression. Using CRISPRi to deplete YY1, we found that YY1 promotes up regulation of TP73-AS1 and the activation of its promoter during TMZ treatment. In addition, we identified two putative YY1 binding sites within the TP73-AS1 promoter, and used mutagenesis to find that they are essential for TMZ mediated promoter activation. Together, our data positions YY1 as an important TP73-AS1 regulator, demonstrating that TP73-AS1 is expressed in the natural and pathological aging brain, including during neurodegeneration and cancer. Our findings advance our understanding of TP73-AS1 expression, bringing forth a new link between TMZ resistance and aging, both of which contribute to GBM morbidity.
Assuntos
Envelhecimento/genética , Encéfalo/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , RNA Longo não Codificante/genética , Temozolomida/farmacologia , Fator de Transcrição YY1/metabolismo , Sequência de Bases , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Linhagem Celular Tumoral , Humanos , Regiões Promotoras Genéticas/genética , RNA Longo não Codificante/metabolismoRESUMO
Infection is the most common cause of mortality in early life, and immunization is the most promising biomedical intervention to reduce this burden. However, newborns fail to respond optimally to most vaccines. Adjuvantation is a key approach to enhancing vaccine immunogenicity, but responses of human newborn leukocytes to most candidate adjuvants, including most TLR agonists, are functionally distinct. Herein, we demonstrate that 3M-052 is a locally acting lipidated imidazoquinoline TLR7/8 agonist adjuvant in mice, which, when properly formulated, can induce robust Th1 cytokine production by human newborn leukocytes in vitro, both alone and in synergy with the alum-adjuvanted pneumococcal conjugate vaccine 13 (PCV13). When admixed with PCV13 and administered i.m. on the first day of life to rhesus macaques, 3M-052 dramatically enhanced generation of Th1 CRM-197-specific neonatal CD4+ cells, activation of newborn and infant Streptococcus pneumoniae polysaccharide-specific (PnPS-specific) B cells as well as serotype-specific antibody titers, and opsonophagocytic killing. Remarkably, a single dose at birth of PCV13 plus 0.1 mg/kg 3M-052 induced PnPS-specific IgG responses that were approximately 10-100 times greater than a single birth dose of PCV13 alone, rapidly exceeding the serologic correlate of protection, as early as 28 days of life. This potent immunization strategy, potentially effective with one birth dose, could represent a new paradigm in early life vaccine development.
Assuntos
Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/imunologia , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologia , Adjuvantes Imunológicos/farmacologia , Adulto , Animais , Linfócitos B/imunologia , Células Cultivadas , Humanos , Recém-Nascido , Macaca mulatta , Linfócitos T/imunologiaRESUMO
The electronic properties of bilayer graphene strongly depend on relative orientation of the two atomic lattices. Whereas Bernal-stacked graphene is most commonly studied, a rotational mismatch between layers opens up a whole new field of rich physics, especially at small interlayer twist. Here we report on magnetotransport measurements on twisted graphene bilayers, prepared by folding of single layers. These reveal a strong dependence on the twist angle, which can be estimated by means of sample geometry. At small rotation, superlattices with a wavelength in the order of 10 nm arise and are observed by friction atomic force microscopy. Magnetotransport measurements in this small-angle regime show the formation of satellite Landau fans. These are attributed to additional Dirac singularities in the band structure and discussed with respect to the wide range of interlayer coupling models.
RESUMO
BACKGROUND: The TLR7/8 agonist 3M-052 and the TLR9 agonist CpG ODN both trigger innate immune responses that support the induction of tumor-specific immunity. Previous studies showed that these agonists used individually could improve the survival of mice challenged with small tumors but were of limited therapeutic benefit against large/advanced tumors. METHODS: Normal mice were challenged with syngeneic tumors. Once these tumors reached clinically detectable size (500-800 mm(3)) they were treated by intra-tumoral injection with 3M-052 and/or CpG ODN. Anti-tumor immunity and tumor growth were evaluated. RESULTS: The co-delivery of agonists targeting TLRs 7, 8 and 9 increased the number and tumoricidal activity of tumor infiltrating CTL and NK cells while reducing the frequency of immunosuppressive MDSC. The combination of 3M-052 plus CpG ODN (but not each agent alone) eradicated large primary tumors and established long-term protective immunity. CONCLUSION: The combination of agonists targeting TLRs 7/8 and 9 represents a significant improvement in cancer immunotherapy.
RESUMO
The human Toll-like receptors (TLRs) are a family of receptors, which sense the presence of various structural elements of pathogens and damaged or effete components in the host. As they do so, they activate two critical arms of host defense, the rapid innate immune response and an adaptive immune response. The innate immune response is typified by the generation of Th1 cytokines, chemokines and type 1 interferons. As such, agonists for the TLRs have potential as antiviral and anticancer therapeutics. They are also well suited to function as vaccine adjuvants. 3M imidazoquinoline (IRM) molecules were the first synthetic small molecules identified as TLR agonists and can affect their biological activities through TLR7, TLR8, or both. The breadth of therapeutic opportunities for this family of molecules can require formulations tailored to the specific application. One consideration is specific formulations to avoid a systemic distribution of these TLR agonists and resulting cytokine storm-like effects on the host. 3M-052 is an IRM bearing a C18 lipid moiety and designed for slow dissemination from the site of application. In the present study 3M-052 has been evaluated for its in vitro TLR activity and for its efficacy as a vaccine adjuvant using a recombinant hemagglutinin from H1N1 A/Puerto Rico/8/34. Given subcutaneously, 3M-052 drives a strong Th1 response to hemagglutinin and serum neutralization of viable H1N1 A/Puerto Rico/8/34 virus in the absence of circulating TNFα or the induction of Th1 cytokines.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Citocinas/metabolismo , Vacinas contra Influenza/imunologia , Quinolinas/administração & dosagem , Receptores Toll-Like/agonistas , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vacinas contra Influenza/administração & dosagem , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células Th1/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologiaRESUMO
Thymine starvation results in a terminal cellular condition known as thymineless death (TLD), which is the basis of action for several common antibiotics and anticancer drugs. We characterized the onset and progression of TLD in Escherichia coli and found that DNA damage is the only salient property that distinguishes cells irreversibly senesced under thymine starvation from cells reversibly arrested by the nucleotide limitation. The damage is manifested as the relative loss of genetic material spreading outward from the replication origin: the extent of TLD correlates with the progression of damage. The reduced lethality in mutants deficient in the RecFOR/JQ repair pathway also correlates with the extent of damage, which explains most of the observed variance in cell killing. We propose that such spatially localized and persistent DNA damage is the consequence of transcription-dependent initiation of replication in the thymine-starved cells and may be the underlying cause of TLD.
Assuntos
Morte Celular , Cromossomos Bacterianos/metabolismo , Replicação do DNA , DNA Bacteriano/metabolismo , Escherichia coli/metabolismo , Origem de Replicação/genética , Timina/metabolismo , Cromossomos Bacterianos/genética , Dano ao DNA , DNA Bacteriano/genética , Escherichia coli/genética , Viabilidade MicrobianaRESUMO
RATIONALE: Edema fluid resorption is critical for gas exchange and requires active epithelial ion transport by Na, K-ATPase and other ion transport proteins. OBJECTIVES: In this study, we sought to determine if alveolar fluid clearance (AFC) is stimulated by 3,3',5 triiodo-L-thyronine (T(3)). METHODS: AFC was measured in in situ ventilated lungs and ex vivo isolated lungs by instilling isosmolar 5% bovine serum albumin solution with fluorescein-labeled albumin tracer and measuring the change in fluorescein isothiocyanate-albumin concentration over time. MEASUREMENTS AND MAIN RESULTS: Systemic treatment with intraperitoneal injections of T(3) for 3 consecutive days increased AFC by 52.7% compared with phosphate-buffered saline-injected control rats. Membranes prepared from alveolar epithelial cells from T(3)-treated rats had higher Na, K-ATPase hydrolytic activity. T(3) (10(-6) M), but not reverse T(3) (3,3',5' triiodo-L-thyronine), applied to the alveolar space increased AFC by 31.8% within 1.5 hours. A 61.5% increase in AFC also occurred by airspace instillation of T(3) in ex vivo isolated lungs, suggesting a direct effect of T(3) on the alveolar epithelium. Exposure of rats to an oxygen concentration of greater than 95% for 60 hours increased wet-to-dry lung weights and decreased AFC, whereas the expression of thyroid receptor was not markedly changed. Airspace T(3) rapidly restored the AFC in rat lungs with hyperoxia-induced lung injury. CONCLUSIONS: Airspace T(3) rapidly stimulates AFC by direct effects on the alveolar epithelium in rat lungs with and without lung injury.
Assuntos
Edema Pulmonar/tratamento farmacológico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Tri-Iodotironina/farmacologia , Animais , Células Cultivadas , Injeções Intraperitoneais , Masculino , Ratos , Ratos Sprague-Dawley , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
Natriuretic peptide receptor A (NPR-A) and natriuretic peptide receptor B (NPR-B) are transmembrane guanylyl cyclases that catalyze the synthesis of cGMP in response to natriuretic peptides. Phosphorylation and dephosphorylation regulate these receptors and have been traditionally studied by (32)PO(4) labeling of transfected cells. However, this approach cannot be used to determine the phosphorylation state of receptors isolated from unlabeled sources. Here, we use Pro-Q Diamond and SYPRO Ruby dyes to quantify the phosphorylation status and protein levels, respectively, of natriuretic peptide receptors from tissues and cells. Strong Pro-Q Diamond signals for NPR-A and NPR-B were obtained when receptors were isolated from lung tissue, liver tissue and overexpressing cells. The level of NPR-A Pro-Q staining was also high in kidney but was much lower in heart tissue. In contrast, the SYPRO Ruby protein signal was weaker and more variable. In a direct comparison, Pro-Q Diamond staining was as sensitive as but more specific than the (32)PO(4) labeling method. The two approaches were highly correlated (R(2) = 0.98). We exploited these techniques to measure the effect of cGMP-dependent protein kinase Ialpha on the phosphate content and guanylyl cyclase activity of NPR-A. Neither value was significantly affected in cells overexpressing cGK-Ialpha or in tissues from mice lacking cGK-I. We conclude that cGK-I does not regulate the cyclase activity or phosphorylation state of NPR-A. Furthermore, we find that Pro-Q Diamond staining is a sensitive method for measuring the phosphate levels of natriuretic peptide receptors, but protein levels are best detected by Western blot analysis, not SYPRO Ruby staining.
Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Guanilato Ciclase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Receptores do Fator Natriurético Atrial/metabolismo , Coloração e Rotulagem/métodos , Animais , Células Cultivadas , Proteína Quinase Dependente de GMP Cíclico Tipo I , Ativação Enzimática , Peptídeos e Proteínas de Sinalização Intracelular/genética , Marcação por Isótopo/métodos , Camundongos , Fosforilação , Ratos , Sensibilidade e Especificidade , Fatores de Tempo , TransfecçãoRESUMO
C-type natriuretic peptide (CNP) activation of the guanylyl cyclase-linked natriuretic peptide receptor-B (NPR-B) stimulates vasorelaxation and bone growth. Hormones and phorbol esters (PMA) inhibit NPR-B in calcium and protein kinase c-dependent manners, respectively. Here, we characterize the kinetic properties of NPR-B in membranes from cells exposed to PMA, the calcium ionophore, ionomycin, or sphingosine-1-phosphate (S1P). PMA and ionomycin primarily increased the K(m) and decreased the V(max) of NPR-B for GTP, respectively, whereas S1P caused modest changes in both parameters. PMA and S1P treatment increased the EC50 for CNP activation by eight- and three-fold, whereas ionomycin was ineffective. All three agents caused NPR-B dephosphorylation, but the basis for the loss of phosphate differed between treatments. In vitro phosphorylation of NPR-B in membranes was markedly diminished by prior whole cell PMA or S1P exposure, whereas ionomycin pretreatment had no effect. The involvement of the known phosphorylated residues in each process was tested with a mutant receptor containing glutamates substituted for these sites. While the effect of PMA was lost on this receptor, the effects of S1P and ionomycin were only partially blocked. Our data suggest that the molecular bases for PMA- and calcium-dependent inhibition of NPR-B are unique. The former results from reduced phosphorylation of a known site and primarily affects the affinity of NPR-B for CNP and GTP. The latter is associated with reductions in maximal velocities by a mechanism that does not involve inhibition of NPR-B phosphorylation and requires a process in addition to the dephosphorylation of the known sites.