RESUMO
Dysfunctional gene expression in nociceptive pathways plays a critical role in the development and maintenance of neuropathic pain. Super enhancers (SEs), composed of a large cluster of transcriptional enhancers, are emerging as new players in the regulation of gene expression. However, whether SEs participate in nociceptive responses remains unknown. Here, we report a spinal-specific SE (SS-SE) that regulates chronic constriction injury (CCI)-induced neuropathic pain by driving Ntmt1 and Prrx2 transcription in dorsal horn neurons. Peripheral nerve injury significantly enhanced the activity of SS-SE and increased the expression of NTMT1 and PRRX2 in the dorsal horn of male mice in a bromodomain-containing protein 4 (BRD4)-dependent manner. Both intrathecal administration of a pharmacological BRD4 inhibitor JQ1 and CRISPR-Cas9-mediated SE deletion abolished the increased NTMT1 and PRRX2 in CCI mice and attenuated their nociceptive hypersensitivities. Furthermore, knocking down Ntmt1 or Prrx2 with siRNA suppressed the injury-induced elevation of phosphorylated extracellular-signal-regulated kinase (p-ERK) and glial fibrillary acidic protein (GFAP) expression in the dorsal horn and alleviated neuropathic pain behaviors. Mimicking the increase in spinal Ntmt1 or Prrx2 in naive mice increased p-ERK and GFAP expression and led to the genesis of neuropathic pain-like behavior. These results redefine our understanding of the regulation of pain-related genes and demonstrate that BRD4-driven increases in SS-SE activity is responsible for the genesis of neuropathic pain through the governance of NTMT1 and PRRX2 expression in dorsal horn neurons. Our findings highlight the therapeutic potential of BRD4 inhibitors for the treatment of neuropathic pain.SIGNIFICANCE STATEMENT SEs drive gene expression by recruiting master transcription factors, cofactors, and RNA polymerase, but their role in the development of neuropathic pain remains unknown. Here, we report that the activity of an SS-SE, located upstream of the genes Ntmt1 and Prrx2, was elevated in the dorsal horn of mice with neuropathic pain. SS-SE contributes to the genesis of neuropathic pain by driving expression of Ntmt1 and Prrx2 Both inhibition of SS-SE with a pharmacological BRD4 inhibitor and genetic deletion of SS-SE attenuated pain hypersensitivities. This study suggests an effective and novel therapeutic strategy for neuropathic pain.
Assuntos
Hipersensibilidade , Neuralgia , Ratos , Masculino , Camundongos , Animais , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Hiperalgesia/metabolismo , Ratos Sprague-Dawley , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neuralgia/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hipersensibilidade/metabolismoRESUMO
Abnormal growth of airway smooth muscle cells is one of the key features in asthmatic airway remodeling, which is associated with asthma severity. The mechanisms underlying inappropriate airway smooth muscle cell growth in asthma remain largely unknown. Myocd has been reported to act as a key transcriptional coactivator in promoting airway-specific smooth muscle development in fetal lungs. Whether Myocd controls airway smooth muscle remodeling in asthma has not been investigated. Mice with lung mesenchyme-specific deletion of Myocd after lung development were generated, and a chronic asthma model was established by sensitizing and challenging the mice with ovalbumin for a prolonged period. Comparison of the asthmatic pathology between the Myocd knockout mice and the wild-type controls revealed that abrogation of Myocd mitigated airway smooth muscle cell hypertrophy and hyperplasia, accompanied by reduced peri-airway inflammation, decreased fibrillar collagen deposition on airway walls, and attenuation of abnormal mucin production in airway epithelial cells. Our study indicates that Myocd is a key transcriptional coactivator involved in asthma airway remodeling. Inhibition of Myocd in asthmatic airways may be an effective approach to breaking the vicious cycle of asthmatic progression, providing a novel strategy in treating severe and persistent asthma. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Assuntos
Remodelação das Vias Aéreas , Asma , Proteínas Nucleares , Animais , Camundongos , Asma/genética , Asma/metabolismo , Modelos Animais de Doenças , Inflamação/patologia , Pulmão/patologia , Camundongos Endogâmicos BALB C , Camundongos Knockout , Miócitos de Músculo Liso/patologia , Proteínas Nucleares/metabolismoRESUMO
Hearing loss is a common disorder affecting nearly 20% of the world's population. Recently, studies have shown that inner ear gene therapy can improve auditory function in several mouse models of hereditary hearing loss. In most of these studies, the underlying mutations affect only a small number of cell types of the inner ear (e.g., sensory hair cells). Here, we applied inner ear gene therapy to the Ildr1Gt(D178D03)Wrst (Ildr1w-/-) mouse, a model of human DFNB42, non-syndromic autosomal recessive hereditary hearing loss associated with ILDR1 variants. ILDR1 is an integral protein of the tricellular tight junction complex and is expressed by diverse inner ear cell types in the organ of Corti and the cochlear lateral wall. We simultaneously applied two synthetic adeno-associated viruses (AAVs) with different tropism to deliver Ildr1 cDNA to the Ildr1w-/- mouse inner ear: one targeting the organ of Corti (AAV2.7m8) and the other targeting the cochlear lateral wall (AAV8BP2). We showed that combined AAV2.7m8/AAV8BP2 gene therapy improves cochlear structural integrity and auditory function in Ildr1w-/- mice.
Assuntos
Surdez , Perda Auditiva , Humanos , Animais , Camundongos , Receptores de Superfície Celular/genética , Surdez/genética , Surdez/terapia , Modelos Animais de Doenças , Terapia GenéticaRESUMO
Circular RNAs (ciRNAs) are emerging as new players in the regulation of gene expression. However, how ciRNAs are involved in neuropathic pain is poorly understood. Here, we identify the nervous-tissue-specific ciRNA-Fmn1 and report that changes in ciRNA-Fmn1 expression in spinal cord dorsal horn neurons play a key role in neuropathic pain after nerve injury. ciRNA-Fmn1 was significantly downregulated in ipsilateral dorsal horn neurons after peripheral nerve injury, at least in part because of a decrease in DNA helicase 9 (DHX9), which regulates production of ciRNA-Fmn1 by binding to DNA-tandem repeats. Blocking ciRNA-Fmn1 downregulation reversed nerve-injury-induced reductions in both the binding of ciRNA-Fmn1 to the ubiquitin ligase UBR5 and the level of ubiquitination of albumin (ALB), thereby abrogating the nerve-injury-induced increase of ALB expression in the dorsal horn and attenuating the associated pain hypersensitivities. Conversely, mimicking downregulation of ciRNA-Fmn1 in naïve mice reduced the UBR5-controlled ubiquitination of ALB, leading to increased expression of ALB in the dorsal horn and induction of neuropathic-pain-like behaviors in naïve mice. Thus, ciRNA-Fmn1 downregulation caused by changes in binding of DHX9 to DNA-tandem repeats contributes to the genesis of neuropathic pain by negatively modulating UBR5-controlled ALB expression in the dorsal horn.
Assuntos
Neuralgia , RNA Circular , Camundongos , Animais , RNA Circular/metabolismo , Regulação para Baixo , DNA Helicases , Hiperalgesia/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Neuralgia/etiologiaRESUMO
BACKGROUND: There is limited information on the difference in epidemiology, clinical characteristics and outcomes of the initial outbreak of the coronavirus disease (COVID-19) in Wuhan (the epicenter) and Sichuan (the peripheral area) in the early phase of the COVID-19 pandemic. This study was conducted to investigate the differences in the epidemiological and clinical characteristics of patients with COVID-19 between the epicenter and peripheral areas of pandemic and thereby generate information that would be potentially helpful in formulating clinical practice recommendations to tackle the COVID-19 pandemic. METHODS: The Sichuan & Wuhan Collaboration Research Group for COVID-19 established two retrospective cohorts that separately reflect the epicenter and peripheral area during the early pandemic. The epidemiology, clinical characteristics and outcomes of patients in the two groups were compared. Multivariate regression analyses were used to estimate the adjusted odds ratios (aOR) with regard to the outcomes. RESULTS: The Wuhan (epicenter) cohort included 710 randomly selected patients, and the peripheral (Sichuan) cohort included 474 consecutive patients. A higher proportion of patients from the periphery had upper airway symptoms, whereas a lower proportion of patients in the epicenter had lower airway symptoms and comorbidities. Patients in the epicenter had a higher risk of death (aOR=7.64), intensive care unit (ICU) admission (aOR=1.66), delayed time from illness onset to hospital and ICU admission (aOR=6.29 and aOR=8.03, respectively), and prolonged duration of viral shedding (aOR=1.64). CONCLUSIONS: The worse outcomes in the epicenter could be explained by the prolonged time from illness onset to hospital and ICU admission. This could potentially have been associated with elevated systemic inflammation secondary to organ dysfunction and prolonged duration of virus shedding independent of age and comorbidities. Thus, early supportive care could achieve better clinical outcomes.
Assuntos
COVID-19/complicações , SARS-CoV-2 , Adulto , Idoso , COVID-19/virologia , China/epidemiologia , Comorbidade , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Eliminação de Partículas ViraisRESUMO
Gliomas are characterized by a malignant phenotype with proliferation, cell cycle arrest and invasion. To explore the biological consequences of epigenetically regulated miRNAs, we performed a microarray-based screening (whose expression was affected by 5-AZA treatment) followed by bisulfite sequencing validation. We found that miR-134 as an epigenetically regulated suppressor gene with prognostic value in gliomas. MicroRNA-134 was downregulated in high-grade gliomas, especially in GBM samples. Functional studies in vitro and in vivo in mouse models showed that overexpression of miR-134 was sufficient to reduce cell cycle arrest, cell proliferation and invasion. Target analysis and functional assays correlated the malignant phenotype with miR-134 target gene KRAS, an established upstream regulator of ERK and AKT pathways. Overall, our results highlighted a role for miR-134 in explaining the malignant phenotype of gliomas and suggested its relevance as a target to develop for early diagnostics and therapy.
Assuntos
Neoplasias Encefálicas/patologia , Regulação Neoplásica da Expressão Gênica/genética , Glioma/patologia , MicroRNAs/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Neoplasias Encefálicas/genética , Inativação Gênica , Glioma/genética , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , FenótipoRESUMO
Irritable bowel syndrome is a disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that stressors presented during gestational periods could have long-term effects on the offspring's tissue structure and function, which may predispose to gastrointestinal diseases. The aim of the present study is to determine whether prenatal maternal stressis a adverse factor affecting gastrointestinal sensitivity and to investigate possible mechanisms underlying prenatal maternal stress-induced visceral hypersensitivity in adult offspring. Prenatal maternal stress was induced in pregnant Sprague-Dawley rats by exposure to heterotypic intermitent stress from gestational day 7 to delivery. Prenatal maternal stress significantly increased visceromotor response to colorectal distention in adult offspring from the age of 6 weeks to 10 weeks. Prenatal maternal stress also enhanced neuronal excitability including depolarization of resting membrane potentials, reduction in rheobase, and an increase in the number of action potentials evoked by 2× and 3× rheobase current stimultion of colon-specific dorsal root ganglion neurons. Prenatal maternal stress remarkably enhanced expression of cystathionine-ß-synthase and Nav1.7 in T13-L2 thoracolumbar dorsal root ganglions both at protein and mRNA levels. Intraperitoneal injection of aminooxyacetic acid, an inhibitor of cystathionine-ß-synthase, attenuated prenatal maternal stress-induced visceral hypersensitivity in a dose-dependent manner. A consecutive seven-day administration of aminooxyacetic acid reversed the hyperexcitability of colon-specific dorsal root ganglion neurons and markedly reduced Nav1.7 expression. These results indicate that the presence of multiple psychophysical stressors during pregnancy is associated with visceral hypersensitivity in offspring, which is likely mediated by an upregualtion of cystathionine-ß-synthase and Nav1.7 expression. Prenatal maternal stress might be a significant contributor to irritable bowel syndrome, and cystathionine-ß-synthase might be a potential target for treatment for chronic visceral hypersensitivity in patients with irritable bowel syndrome.
Assuntos
Cistationina beta-Sintase/metabolismo , Efeitos Tardios da Exposição Pré-Natal/enzimologia , Células Receptoras Sensoriais/enzimologia , Transdução de Sinais , Estresse Psicológico/complicações , Dor Visceral/enzimologia , Dor Visceral/etiologia , Animais , Células Cultivadas , Colo/inervação , Colo/patologia , Cistationina beta-Sintase/antagonistas & inibidores , Cistationina beta-Sintase/genética , Eletromiografia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Masculino , Canal de Sódio Disparado por Voltagem NAV1.7/genética , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Especificidade de Órgãos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/patologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Dor Visceral/patologiaRESUMO
Curcumin is a polyphenol extracted from turmeric rhizome and has multiple pharmacological roles. Recently,its anticancer properties have been recognized. Also,curcumin regulates autophagy in tumor cells via signaling pathways including AMP-activated protein kinase,mammalian target of rapamycin,transcription factor EB,Beclin-1,B-cell lymphoma 2,and endoplasmic reticulum stress. Considering the complicated crosstalk between autophagy and apoptosis,in this article we summaize the mechanism of curcumin-induced autophagy and its effect on apoptosis,with an attempt to provide insights on tumor therapy.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Autofagia , Curcumina/farmacologia , Neoplasias/tratamento farmacológico , Transdução de Sinais , Proteínas Quinases Ativadas por AMP , Animais , Apoptose , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Proteína Beclina-1 , Estresse do Retículo Endoplasmático , Humanos , Proteínas Proto-Oncogênicas c-bcl-2 , Serina-Treonina Quinases TORRESUMO
Flowering time (i.e., heading date in crops) is an important ecological trait that determines growing seasons and regional adaptability of plants to specific natural environments. Rice (Oryza sativa L.) is a short-day plant that originated in the tropics. Increasing evidence suggests that the northward expansion of cultivated rice was accompanied by human selection of the heading date under noninductive long-day (LD) conditions. We report here the molecular cloning and characterization of DTH2 (for Days to heading on chromosome 2), a minor-effect quantitative trait locus that promotes heading under LD conditions. We show that DTH2 encodes a CONSTANS-like protein that promotes heading by inducing the florigen genes Heading date 3a and RICE FLOWERING LOCUS T 1, and it acts independently of the known floral integrators Heading date 1 and Early heading date 1. Moreover, association analysis and transgenic experiments identified two functional nucleotide polymorphisms in DTH2 that correlated with early heading and increased reproductive fitness under natural LD conditions in northern Asia. Our combined population genetics and network analyses suggest that DTH2 likely represents a target of human selection for adaptation to LD conditions during rice domestication and/or improvement, demonstrating an important role of minor-effect quantitative trait loci in crop adaptation and breeding.
Assuntos
Produtos Agrícolas/genética , Genes de Plantas , Oryza/genética , Polimorfismo Genético , Ásia , Ritmo Circadiano , Clonagem Molecular , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Ativação Transcricional , Regulação para CimaRESUMO
Prolonged exposure to opiates induces a constellation of neuroadaptations, especially in the mesolimbic dopamine system (MLDS), which leads to alteration in the function of motivational circuitry. The neural cell adhesion molecule (NCAM) mediates cell-cell interactions and plays an important role in processes associated with neural plasticity. Moreover, it has been shown that NCAM were related to risk of alcoholism in human populations. Here, coimmunoprecipitation and western blotting were used to investigate whether morphine treatment induced alteration of the expression of NCAM or its signaling level in MLDS. The rats receiving escalating dose of morphine treatment were divided into three groups: morphine 1d, 3d and 5d group, which were injected subcutaneously with morphine hydrochloride for 1 day, 3 days and 5 days, respectively. Twelve hours after the last injection, animals were sacrificed and the tissues of ventral tegmental area (VTA), prefrontal cortex (PFC) and nucleus accumbens (NAc) were punched out to examine the expression of NCAM or its signaling level. The results showed that morphine treatment had no significant effect on the expression of NCAM, but downregulated the phosphorylation of NCAM-associated focal adhesion kinase (FAK) in the VTA and PFC of rats. In the NAc of rats, however, the expression of NCAM and its signaling were not altered significantly by morphine treatment. These results indicated that the downregulation of NCAM signaling in the VTA and PFC might be involved in the formation of morphine addiction.
Assuntos
Morfina/toxicidade , Moléculas de Adesão de Célula Nervosa/metabolismo , Núcleo Accumbens/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Transdução de Sinais , Área Tegmentar Ventral/efeitos dos fármacos , Animais , Western Blotting , Relação Dose-Resposta a Droga , Imunoprecipitação , Injeções Subcutâneas , Masculino , Moléculas de Adesão de Célula Nervosa/genética , Núcleo Accumbens/metabolismo , Fosforilação , Córtex Pré-Frontal/metabolismo , Ratos Sprague-Dawley , Área Tegmentar Ventral/metabolismoRESUMO
Low temperature (LT) is one of the most prevalent factors limiting the productivity and geographical distribution of rice (Oryza sativa L.). Although significant progress has been made in elucidating the effect of LT on seed germination and reproductive development in rice, the genetic component affecting vegetative growth under LT remains poorly understood. Here, we report that rice cultivars harboring the dominant LTG1 (Low Temperature Growth 1) allele are more tolerant to LT (15-25°C, a temperature range prevalent in high-altitude, temperate zones and high-latitude areas), than those with the ltg1 allele. Using a map-based cloning strategy, we show that LTG1 encodes a casein kinase I. A functional nucleotide polymorphism was identified in the coding region of LTG1, causing a single amino acid substitution (I357K) that is associated with the growth rate, heading date and yield of rice plants grown at LT. We present evidence that LTG1 affects rice growth at LT via an auxin-dependent process(es). Furthermore, phylogenetic analysis of this locus suggests that the ltg1 haplotype arose before the domestication of rice in tropical climates. Together, our data demonstrate that LTG1 plays an important role in the adaptive growth and fitness of rice cultivars under conditions of low ambient temperature.
Assuntos
Adaptação Fisiológica , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Alelos , Substituição de Aminoácidos , Caseína Quinase I/genética , Caseína Quinase I/metabolismo , Clonagem Molecular , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Haplótipos , Ácidos Indolacéticos/metabolismo , Oryza/genética , Oryza/crescimento & desenvolvimento , Filogenia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Polimorfismo GenéticoRESUMO
The objective of this study is to explore the expression pattern, prognostic value, and functional role of RAB34 in gliomas. RAB34 messenger RNA (mRNA) expression was evaluated from low grade to high grade in 220 glioma patients of the Chinese Glioma Genome Atlas (CGGA). We therefore analyzed RAB34 mRNA expression in two validated datasets. For detecting the protein expression level of RAB34, another 104 glioma tissues were stained by immunohistochemistry. Gene ontology (GO) analysis and gene set variation analysis (GSVA) were used for functional annotation of RAB34. The mRNA and protein expression levels of RAB34 were both related to glioma grade progression and were inversely correlated with overall survival (OS) in high-grade glioma patients. GO analysis and GSVA showed that RAB34 sets related to migration were significantly enriched in the cases with RAB34 high expression. Pearson correlation analysis identified that genes including MMP-11, HSPB1, IGFBP2, HSPA6, IGFBP5, and MMP19 were positively correlated with RAB34. The expression of RAB34 is related to glioma grade progression and confers a poor prognosis in high-grade glioma patients.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Glioma/genética , Proteínas rab de Ligação ao GTP/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/patologia , Humanos , Proteínas Nucleares , Prognóstico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Proteínas rab de Ligação ao GTP/metabolismoRESUMO
Objective : The aim of study was to investigate the distribution of the integrons in Escherichia coli (E. coli) isolates, and analyze the possible relationship between the antimicrobial resistance profiles and the integrons. Methods : The antimicrobial profiles of 376 E. coli strains were analysed by disk diffusion test. The integron genes and variable regions were detected by PCR. Some amplicons were sequenced to determine the gene cassettes style. Results : Of 376 isolates, 223 isolates (59.3%) were confirmed as ESBL-EC. Comparison to ESBL-negative E. coli, the high rates of resistance to the third and fourth generation of cephalosporins, penicillins and amikacin were found in ESBL-EC. Only class 1 was integron detected in the isolates, and the prevalence of it was 66.5%. It was commonly found in ESBL-EC (77.6%, 173/223), which was higher than that of ESBL-negative E. coli (50.3%, 77/153) (p<0.001). Six different genes cassettes were detected in this study and were classified into three groups: dfr17-aadA5, dfrA12-aadA2 and aacA4-CmlA1. Additionally, more than one gene array harboured in 13.9% isolates of ESBL-EC, while in 9.1% isolates of ESBL-negative E.coli. Conclusion : The high incidence of ESBL-EC with resistance to multiple antibiotics were detected in the isolates from Blood stream infection (BSI). More resistant gene cassettes in ESBL-EC may partially underlie the high resistance to amikacin, while no relation exists between the high incidence of ESBL-EC and classes 1~ 3 integrons in this region.
RESUMO
Abnormal lung development can cause congenital pulmonary cysts, the mechanisms of which remain largely unknown. Although the cystic lesions are believed to result directly from disrupted airway epithelial cell growth, the extent to which developmental defects in lung mesenchymal cells contribute to abnormal airway epithelial cell growth and subsequent cystic lesions has not been thoroughly examined. In the present study, we dissected the roles of BMP receptor 1a (Bmpr1a)-mediated BMP signaling in lung mesenchyme during prenatal lung development and discovered that abrogation of mesenchymal Bmpr1a disrupted normal lung branching morphogenesis, leading to the formation of prenatal pulmonary cystic lesions. Severe deficiency of airway smooth muscle cells and subepithelial elastin fibers were found in the cystic airways of the mesenchymal Bmpr1a knockout lungs. In addition, ectopic mesenchymal expression of BMP ligands and airway epithelial perturbation of the Sox2-Sox9 proximal-distal axis were detected in the mesenchymal Bmpr1a knockout lungs. However, deletion of Smad1/5, two major BMP signaling downstream effectors, from the lung mesenchyme did not phenocopy the cystic abnormalities observed in the mesenchymal Bmpr1a knockout lungs, suggesting that a Smad-independent mechanism contributes to prenatal pulmonary cystic lesions. These findings reveal for the first time the role of mesenchymal BMP signaling in lung development and a potential pathogenic mechanism underlying congenital pulmonary cysts.
RESUMO
Abnormal lung development can cause congenital pulmonary cysts, the mechanisms of which remain largely unknown. Although the cystic lesions are believed to result directly from disrupted airway epithelial cell growth, the extent to which developmental defects in lung mesenchymal cells contribute to abnormal airway epithelial cell growth and subsequent cystic lesions has not been thoroughly examined. In the present study using genetic mouse models, we dissected the roles of bone morphogenetic protein (BMP) receptor 1a (Bmpr1a)-mediated BMP signaling in lung mesenchyme during prenatal lung development and discovered that abrogation of mesenchymal Bmpr1a disrupted normal lung branching morphogenesis, leading to the formation of prenatal pulmonary cystic lesions. Severe deficiency of airway smooth muscle cells and subepithelial elastin fibers were found in the cystic airways of the mesenchymal Bmpr1a knockout lungs. In addition, ectopic mesenchymal expression of BMP ligands and airway epithelial perturbation of the Sox2-Sox9 proximal-distal axis were detected in the mesenchymal Bmpr1a knockout lungs. However, deletion of Smad1/5, two major BMP signaling downstream effectors, from the lung mesenchyme did not phenocopy the cystic abnormalities observed in the mesenchymal Bmpr1a knockout lungs, suggesting that a Smad-independent mechanism contributes to prenatal pulmonary cystic lesions. These findings reveal for the first time the role of mesenchymal BMP signaling in lung development and a potential pathogenic mechanism underlying congenital pulmonary cysts.
Congenital disorders are medical conditions that are present from birth. Although many congenital disorders are rare, they can have a severe impact on the quality of life of those affected. For example, congenital pulmonary airway malformation (CPAM) is a rare congenital disorder that occurs in around 1 out of every 25,000 pregnancies. In CPAM, abnormal, fluid-filled sac-like pockets of tissue, known as cysts, form within the lungs of unborn babies. After birth, these cysts become air-filled and do not behave like normal lung tissue and stop a baby's lungs from working properly. In severe cases, babies with CPAM need surgery immediately after birth. We still do not understand exactly what the underlying causes of CPAM might be. CPAM is not considered to be hereditary that is, it does not appear to be passed down in families nor is it obviously linked to any environmental factors. CPAM is also very difficult to study, because researchers cannot access tissue samples during the critical early stages of the disease. To overcome these difficulties, Luo et al. wanted to find a way to study CPAM in the laboratory. First, they developed a non-human animal 'model' that naturally forms CPAM-like lung cysts, using genetically modified mice where the gene for the signaling molecule Bmpr1a had been deleted in lung cells. Normally, Bmpr1a is part of a set of the molecular instructions, collectively termed BMP signaling, which guide healthy lung development early in life. However, mouse embryos lacking Bmpr1a developed abnormal lung cysts that were similar to those found in CPAM patients, suggesting that problems with BMP signalling might also trigger CPAM in humans. Luo et al. also identified several other genes in the Bmpr1a-deficient mouse lungs that had abnormal patterns of activity. All these genes were known to be controlled by BMP signaling, and to play a role in the development and organisation of lung tissue. This suggests that when these genes are not controlled properly, they could drive formation of CPAM cysts when BMP signaling is compromised. This work is a significant advance in the tools available to study CPAM. Luo et al.'s results also shed new light on the molecular mechanisms underpinning this rare disorder. In the future, Luo et al. hope this knowledge will help us develop better treatments for CPAM, or even help to prevent it altogether.
Assuntos
Receptores de Proteínas Morfogenéticas Ósseas Tipo I , Pulmão , Mesoderma , Camundongos Knockout , Transdução de Sinais , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/deficiência , Camundongos , Pulmão/embriologia , Pulmão/metabolismo , Pulmão/patologia , Mesoderma/embriologia , Mesoderma/metabolismo , Cistos/metabolismo , Cistos/patologia , Cistos/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/genética , Pneumopatias/metabolismo , Pneumopatias/patologia , Pneumopatias/genética , Modelos Animais de DoençasRESUMO
ABSTRACT: Nerve injury-induced aberrant changes in gene expression in spinal dorsal horn neurons are critical for the genesis of neuropathic pain. N6-methyladenine (m 6 A) modification of DNA represents an additional layer of gene regulation. Here, we report that peripheral nerve injury significantly decreased the level of m 6 A-specific DNA methyltransferase 1 ( N6amt1 ) in dorsal horn neurons. This decrease was attributed, at least partly, to a reduction in transcription factor Nr2f6 . Rescuing the decrease in N6amt1 reversed the loss of m 6 A at the promoter for inwardly rectifying potassium channel subfamily J member 16 ( Kcnj16 ), mitigating the nerve injury-induced upregulation of Kcnj16 expression in the dorsal horn and alleviating neuropathic pain hypersensitivities. Conversely, mimicking the downregulation of N6amt1 in naive mice erased DNA m 6 A at the Kcnj16 promoter, elevated Kcnj16 expression, and led to neuropathic pain-like behaviors. Therefore, decreased N6amt1 caused by NR2F6 is required for neuropathic pain, likely through its regulation of m 6 A-controlled KCNJ16 in dorsal horn neurons, suggesting that DNA m 6 A modification may be a potential new target for analgesic and treatment strategies.
Assuntos
Neuralgia , DNA Metiltransferases Sítio Específica (Adenina-Específica) , Animais , Camundongos , Regulação para Baixo , Hiperalgesia/metabolismo , Neuralgia/genética , Neuralgia/metabolismo , Células do Corno Posterior/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Regulação para Cima , DNA Metiltransferases Sítio Específica (Adenina-Específica)/metabolismoRESUMO
Chronic inflammatory pain caused by neuronal hyperactivity is a common and refractory disease. Kv3.1, a member of the Kv3 family of voltage-dependent K+ channels, is a major determinant of the ability of neurons to generate high-frequency action potentials. However, little is known about its role in chronic inflammatory pain. Here, we show that although Kv3.1 mRNA expression was unchanged, Kv3.1 protein expression was decreased in the dorsal spinal horn of mice after plantar injection of complete Freund's adjuvant (CFA), a mouse model of inflammatory pain. Upregulating Kv3.1 expression alleviated CFA-induced mechanical allodynia and heat hyperalgesia, whereas downregulating Kv3.1 induced nociception-like behaviors. Additionally, we found that ubiquitin protein ligase E3 component n-recognin 5 (UBR5), a key factor in the initiation of chronic pain, binds directly to Kv3.1 to drive its ubiquitin degradation. Intrathecal injection of the peptide TP-CH-401, a Kv3.1 ubiquitination motif sequence, rescued the decrease in Kv3.1 expression and Kv currents through competitive binding to UBR5, and consequently attenuated mechanical and thermal hypersensitivity. These findings demonstrate a previously unrecognized pathway of Kv3.1 abrogation by UBR5 and indicate that Kv3.1 is critically involved in the regulation of nociceptive behavior. Kv3.1 is thus a promising new target for treating inflammatory pain.
RESUMO
Glial-cell-line-derived neurotrophic factor (GDNF) has been shown to protect dopaminergic (DA) neurons against 6-hydroxydopamine (6-OHDA) toxicity. The mechanism underlying the antiapoptosis role of GDNF still needs further studies. We previously observed that nuclear factor-kappaB (NF-κB) signaling pathway, i.e. p65/p52, mediated the antiapoptosis role of GDNF in MN9D cells. Here, the DA cell line MN9D was used to explore the mechanisms underlying NF-κB p65/p52-mediated protection role of GDNF in DA neurons. The results showed that GDNF pretreatment blocked the apoptotic effects induced by 6-OHDA, with the upregulation of the antiapoptotic protein, Bcl-2 and Bcl-w, as well as the downregulation of the proapoptotic proteins, Bax and Bad. Furthermore, when sip100 plasmids were transfected into MN9D cells to inhibit the expression of p100, which was the precursor of p52, the effects of GDNF on upregulating Bcl-2 and Bcl-w were attenuated. These results indicated that GDNF could protect MN9D cells from apoptosis induced by 6-OHDA via upregulating Bcl-2 and Bcl-w expressions and downregulating Bax and Bad expressions. Moreover, NF-κB p65/p52 signaling mediated the effects of GDNF on Bcl-2 and Bcl-w expressions.
Assuntos
Apoptose/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Genes bcl-2/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Hidroxidopaminas/farmacologia , Subunidade p52 de NF-kappa B/genética , Proteínas/genética , Fator de Transcrição RelA/genética , Animais , Proteínas Reguladoras de Apoptose , Western Blotting , Neurônios Dopaminérgicos/efeitos dos fármacos , Mesencéfalo/citologia , Camundongos , Subunidade p52 de NF-kappa B/fisiologia , Plasmídeos/genética , RNA Interferente Pequeno/genética , Fator de Transcrição RelA/fisiologia , Transfecção , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo , Proteína de Morte Celular Associada a bcl/genética , Proteína de Morte Celular Associada a bcl/metabolismoRESUMO
Mangrove soil is a reliable source for screening cellulose-degrading bacteria due to the high diversity of microbes. To effectively utilize crop straw resources, a cellulolytic bacterium, Paenibacillus silvae strain CH2 was isolated from mangrove soil. We determined the carboxymethyl cellulose (CMC) and filter paper assay (FPA) activities of CH2 at different incubation times, NaCl concentrations, pH and temperatures, estimated the degradation efficiencies of rice and maize straw by CH2, sequenced and analyzed the whole genome of CH2. The results showed that along with the increases of incubation time, NaCl concentration, pH and temperature, the CMC and FPA activities increased first and then decreased . The highest CMC and FPA activities were observed at incubation time of 72-84 h, NaCl concentration of 6.0 g·L-1, pH of 7 and temperature of 36 â. Degradation of straw assays revealed that CH2 could effectively degrade rice and maize straw. At 0 g·L-1 NaCl (the control), the 10-day degradation rates of rice and maize straw were 30.4% and 47.0%, respectively. In the presence of 15 g·L-1 NaCl, the degradation rates were not significantly different from the control, indicating that CH2 had a high tolerance to salts. The whole genome of P. silvae CH2 was 6797325 bp, containing 6312 coding genes. P. silvae CH2 contained multiple genes encoding cellulose and hemicellulose degrading enzymes. These enzymes mainly belonged to the GH family, including endo-1,4-ß-xylanase, Xylan 1,4-ß-xylosidase, ß-glucosidase, and endoglucanase. The results indicated that the bacterium had the potential to be used in crop straw degradation.
Assuntos
Paenibacillus , Cloreto de Sódio , Celulose , Paenibacillus/genética , Paenibacillus/metabolismo , Genômica , SoloRESUMO
Toosendanin (TSN) is an active compound from the fruit of Melia toosendan Sieb et Zucc. TSN has been shown to have broad-spectrum anti-tumour activities in human cancers. However, there are still many gaps in the knowledge of TSN on canine mammary tumours (CMT). CMT-U27 cells were used to select the optimal acting time and best concentration of TSN to initiate apoptosis. Cell proliferation, cell colony formation, cell migration and cell invasion were analysed. The expression of apoptosis-related genes and proteins were also detected to explore the mechanism of action of TSN. A murine tumour model was established to detect the effect of TSN treatments. The results showed that TSN decreased cell viability of migration and invasion, altered CMT-U27 cell morphology, and inhibited DNA synthesis. TSN-induced cell apoptosis by upregulating BAX, cleaved caspase-3, cleaved caspase-9, p53 and cytochrome C (cytosolic) protein expression, and downregulating Bcl-2 and cytochrome C (mitochondrial) expression. In addition, TSN increased the mRNA transcription levels of cytochrome C, p53 and BAX, and decreased the mRNA expression of Bcl-2. Furthermore, TSN inhibited the growth of CMT xenografts by regulating the expression of genes and proteins activated by the mitochondrial apoptotic pathway. In conclusion, TSN effectively inhibited cell proliferation, migration and invasion activity, as well as induced CMT-U27 cell apoptosis. The study provides a molecular basis for the development of clinical drugs and other therapeutic options.