Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
1.
Cancer Cell ; 38(6): 844-856.e7, 2020 12 14.
Article in English | MEDLINE | ID: mdl-33186520

ABSTRACT

Ependymoma is the third most common pediatric tumor with posterior fossa group A (PFA) being its most aggressive subtype. Ependymomas are generally refractory to chemotherapies and thus lack any effective treatment. Here, we report that elevated expression of CXorf67 (chromosome X open reading frame 67), which frequently occurs in PFA ependymomas, suppresses homologous recombination (HR)-mediated DNA repair. Mechanistically, CXorf67 interacts with PALB2 and inhibits PALB2-BRCA2 interaction, thereby inhibiting HR repair. Concordantly, tumor cells with high CXorf67 expression levels show increased sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors, especially when combined with radiotherapy. Thus, our findings have revealed a role of CXorf67 in HR repair and suggest that combination of PARP inhibitors with radiotherapy could be an effective treatment option for PFA ependymomas.


Subject(s)
BRCA2 Protein/metabolism , Ependymoma/therapy , Fanconi Anemia Complementation Group N Protein/metabolism , Infratentorial Neoplasms/therapy , Oncogene Proteins/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/administration & dosage , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Chemoradiotherapy , Ependymoma/genetics , Ependymoma/metabolism , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Gene Expression Regulation, Neoplastic/radiation effects , Humans , Infratentorial Neoplasms/genetics , Infratentorial Neoplasms/metabolism , Mice , Oligonucleotide Array Sequence Analysis , Oncogene Proteins/genetics , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Recombinational DNA Repair/drug effects , Recombinational DNA Repair/radiation effects , Up-Regulation , Xenograft Model Antitumor Assays
2.
Sci Prog ; 103(1): 36850419884452, 2020.
Article in English | MEDLINE | ID: mdl-31829894

ABSTRACT

Long-distance gas pipelines generally have complex, undulating sections. Trapped air pockets are often present at the high points or ends of pipelines. This article carries out an experimental research to figure out the transient changes. First of all, under the condition of using the pig with 231 g and the injection pressure of 0.3 MPa, the hydraulic pulse increases from 0.31 to 0.54 MPa as the liquid level rises from 1 to 8 m. And at the liquid level of 8 m, the injection pressure grows from 0.3 to 0.75 MPa and the hydraulic pulse from 0.54 to 0.95 MPa. When the interception air mass is located at the blind side of the pipeline's end, the injection pressure is 0.75 MPa, and the hydraulic pulse decreases from 4.9 to 3.21 MPa with the increase in the void fraction. The maximum hydraulic pressure generates when the air pocket is located at the rear end of the drainage system (4.9 MPa) is far higher than that when the air pocket is located in front of the pig (1.0 MPa). Therefore, it is necessary to minimize the generation of trapped air pockets at the rear end of the pipeline system to ensure safety.

3.
Am J Surg Pathol ; 44(3): 329-339, 2020 03.
Article in English | MEDLINE | ID: mdl-31688142

ABSTRACT

Follicular lymphoma (FL) is one of the most frequently diagnosed lymphomas in the United States and Europe. The definition of and basic approach to diagnosis and grading of FL is essentially unchanged in the recently updated revision of the World Health Organization (WHO) classification. FL is a biologically and histopathologically heterogeneous disease. Although there is an improved understanding of some FL variants and specific subtypes, there are cases whose recognition is particularly challenging, either because they have unusual features or represent examples of new or rare variants. Herein, we share a series of unusual and difficult to recognize FLs with the goal of increasing awareness of the expanding histopathologic variability in FL. Unusual FL discussed here include: FL with Castleman-like changes, FL with plasmacytic differentiation, and immunoglobulin G4-positive plasma cells in the setting of immunoglobulin G4-related disease, FL with marginal zone differentiation and involving mucosa-associated lymphoid tissue sites, diffuse FL variant expressing CD23 with STAT6 mutation, large B-cell lymphoma with IRF4 rearrangement, CD10-negative and MUM1-positive aggressive FL, and Epstein-Barr virus-positive FL.


Subject(s)
Lymphoma, Follicular/diagnosis , Lymphoma, Follicular/pathology , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Diagnosis, Differential , Female , Humans , Lymphoma, Follicular/genetics , Lymphoma, Follicular/metabolism , Male , Middle Aged
4.
Case Rep Hematol ; 2018: 5761953, 2018.
Article in English | MEDLINE | ID: mdl-30363761

ABSTRACT

Prolymphocytic transformation is a concept usually applied in the context of chronic lymphocytic leukemia/small lymphocytic lymphoma to describe the presence of a high percentage of prolymphocytes in peripheral blood (usually more than 55%). Prolymphocytic transformation has also been reported in mantle cell lymphoma (MCL) but only rarely in splenic marginal zone lymphoma (SMZL). We present two splenic B-cell lymphomas presenting in the leukemic phase and with increased prolymphocytes, both classified as SMZL with prolymphocytic transformation. One case clinically simulated B-prolymphocytic leukemia (B-PLL). Both lymphomas were very unusual because the tumor cells diffusely and strongly expressed cyclin D1 despite lacking the t(11; 14)(q13; q32) as detected by several approaches including next-generation sequencing, fluorescence in situ hybridization using CCND1 break apart probe and fusion probes for t(11; 14)(q13; q32), and conventional karyotyping. These cases therefore simulated prolymphocytic variants of MCL. The incidence of this phenomenon is unknown, and awareness of this potential alternate protein expression pattern is important in order to avoid diagnostic errors.

5.
Mol Cytogenet ; 11: 43, 2018.
Article in English | MEDLINE | ID: mdl-30123325

ABSTRACT

BACKGROUND: Partial monosomy 21 is a rare finding with variable sizes and deletion breakpoints, presenting with a broad spectrum of phenotypes. CASE PRESENTATION: We report a 10-month-old boy with short stature, minor anomalies and mild motor delay. The patient had a monosomy 21 and duplication of the 21q22.11q22.3 region on the remaining derivative chromosome 21 which represents a partial 21q uniparental disomy of paternal origin, upd(21q22.11q22.3)pat. The abnormalities were characterized by karyotyping, FISH, chromosomal microarray, and genotyping. CONCLUSIONS: This is the first case showing a monosomy 21 compensated by upd(21q22.11q22.3) as a mechanism of genomic rescue. Because there is no strong evidence showing imprinting on chromosome 21, the uniparental disomy itself is not associated with abnormal phenotype but has reduced phenotype severity of monosomy 21. We reviewed the previously published cases with isolated 21q deletions and identified a common deletion of 5.7 Mb associated with low birth weight, length and head circumference in the 21q21.2 region.

6.
Am J Clin Pathol ; 145(5): 710-6, 2016 May.
Article in English | MEDLINE | ID: mdl-27124935

ABSTRACT

OBJECTIVES: Primary mediastinal large B-cell lymphomas (PMLBCLs) are aggressive lymphomas with characteristic clinical, morphologic, and immunophenotypic features. "Double-hit" (DH) lymphomas are B-cell neoplasms characterized by a translocation involving MYC and either BCL2 or BCL6 In the indexed literature, there are no reported cases of PMLBCL associated with DH or triple-hit events. METHODS: Herein, we present a case of a 15-year-old girl with PMLBCL who had typical clinical, morphologic, and immunophenotypic features. RESULTS: Fluorescent in situ hybridization studies showed rearrangements involving MYC and BCL6 We also excluded the possibility of a reciprocal t(3;8) (3q27;8q24) BCL6/MYC translocation. CONCLUSIONS: This case expands the current spectrum of lymphomas subtypes in which DH can be found and supports the rationale for cytogenetic testing for DH abnormalities in all cases of aggressive large B-cell lymphomas regardless of subtype.


Subject(s)
Lymphoma, Large B-Cell, Diffuse/genetics , Mediastinal Neoplasms/genetics , Proto-Oncogene Proteins c-bcl-6/genetics , Proto-Oncogene Proteins c-myc/genetics , Adolescent , Female , Genes, myc , Humans , In Situ Hybridization, Fluorescence , Lymphoma, Large B-Cell, Diffuse/pathology , Mediastinal Neoplasms/pathology , Translocation, Genetic
7.
Breast Cancer Res Treat ; 155(3): 457-62, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26895325

ABSTRACT

The status of human epidermal growth factor receptor 2 (HER2, ERBB2) determines the eligibility of breast cancer patients to receive HER2-targeted therapy. The majority of HER2 testing in the U.S. is performed using a combination of immunohistochemistry (IHC) screening followed by fluorescence in situ hybridization (FISH) for IHC equivocal cases. In 2013, the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) updated the guideline for HER2 testing. This study evaluates the impact of the 2013 ASCO/CAP updated guideline on final HER2 FISH classification of breast cancers with an equivocal IHC result. For each case, we reported a FISH result according to the 2013 updated guideline and recorded a separated result using the 2007 guideline for investigational purpose. McNemar's test and Bowker's symmetry test were used to compare the classifications by the two guidelines. Among 172 HER2 IHC 2+ equivocal cases, use of the 2103 guideline changed classifications in 36 cases (21 %) when compared with the results expected by use of the 2007 guideline, and yielded a higher proportion of positive (28.5 vs. 23.3 %) and equivocal (16.3 vs. 4.1 %), and a lower proportion of negative (55.2 vs. 72.7 %) cases (p < 0.001). The major classification change with use of the updated guideline is from the HER2 FISH negative to equivocal in 26 cases (15 %). Our study has shown that implementation of the 2013 ASCO/CAP updated guideline has significant impact on HER2 classification for breast cancers with an equivocal HER2 IHC result and therefore increased the use of HER2-targeted therapy. Our data have also shown that reflex FISH is effective for final classification of the IHC equivocal cases and that polysomy 17 (CEP17 copy number ≥3/cell) is present in a significantly higher proportion of cases with an equivocal HER2 FISH classification.


Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/genetics , In Situ Hybridization, Fluorescence/methods , Receptor, ErbB-2/genetics , Breast Neoplasms/classification , Breast Neoplasms/diagnosis , Breast Neoplasms/pathology , Chromosome Aberrations , Chromosomes, Human, Pair 17/genetics , Female , Guidelines as Topic , Humans
8.
ACS Appl Mater Interfaces ; 7(51): 28156-65, 2015 Dec 30.
Article in English | MEDLINE | ID: mdl-26647284

ABSTRACT

A series of fluorene derivatives end-capped with diphenylamino and oxadiazolyl were synthesized, and their photophysical and electrochemical properties are reported. Aggregation-induced emission (AIE) effects were observed for the materials, and bipolar characteristics of the molecules are favored with measurement of carrier mobility and calculation of molecular orbitals using density functional theory (DFT). Using the fluorene derivatives as emitting-layer, nondoped organic light-emitting devices (OLEDs) have been fabricated by spin-coating in the configuration ITO/PEDOT:PSS(35 nm)/PVK(15 nm)/PhN-OF(n)-Oxa(80 nm)/SPPO13(30 nm)/Ca(8 nm)/Al(100 nm) (n = 2-4). The best device with PhN-OF(2)-Oxa exhibits a maximum luminance of 14 747 cd/m(2), a maximum current efficiency of 4.61 cd/A, and an external quantum efficiency (EQE) of 3.09% in the blue region. Investigation of the correlation between structures and properties indicates that there is no intramolecular charge transfer (ICT) increase in these molecules with the increase of conjugation length. The device using material of the shortest conjugation length as emitting-layer gives the best electroluminescent (EL) performances in this series of oligofluorenes.

9.
J Gastroenterol Hepatol ; 29(8): 1654-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24628622

ABSTRACT

BACKGROUND AND AIM: Diagnosis of pancreatic malignancy is often based on cytological specimens collected by endoscopic ultrasound guided fine needle aspiration (EUS FNA). Several factors can decrease sensitivity of EUS FNA for pancreatic cancer: well-differentiated tumors, pancreatitis, blood, necrosis and slides with low cellularity. The objective of this study is to report on the use of fluorescence in situ hybridization (FISH) analysis combined with cytology in pancreatic masses. METHODS: EUS database and medical records of patients referred for EUS between January 2009 through august 2013 were reviewed. Data on cytology, FISH and surgical pathology were reviewed. Surgical pathology, death or extended clinical follow-up were used to verify correct diagnosis of malignancy. FISH performed using a four-set DNA probe for chromosomes 3, 7, 17, and band 9p21 in patients with inconclusive immediate cytology reading. Sensitivity of cytology and FISH were compared. RESULTS: Study cohort comprised of 104 patients with FISH analysis on EUS FNA specimens of pancreatic masses (74 adenocarcinoma, 7 neuroendocrine tumor and 23 benign. Sensitivity of cytology and FISH for carcinoma was respectively: 62% and 81%. Sensitivity of FISH + cytology was 89%. The specificity of FISH and cytology was 100%. The most common abnormality on FISH was a 9p21 deletion seen in 43 patients (58%) followed by polysomy of 7 (46%). FISH detected malignancy in 23 patients with negative cytology. CONCLUSIONS: In patients with inconclusive immediate cytology reading, FISH is superior to cytology and improves overall sensitivity. The 9p21 deletion is the most common abnormality seen in this cohort of patients with pancreatic cancer.


Subject(s)
Adenocarcinoma/diagnosis , Adenocarcinoma/pathology , Cytodiagnosis/methods , In Situ Hybridization, Fluorescence/methods , Neuroendocrine Tumors/diagnosis , Neuroendocrine Tumors/pathology , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/pathology , Adenocarcinoma/genetics , Adult , Aged , Aged, 80 and over , Chromosome Deletion , Chromosomes, Human, Pair 9/genetics , Cohort Studies , Endoscopic Ultrasound-Guided Fine Needle Aspiration , Female , Humans , Male , Middle Aged , Neuroendocrine Tumors/genetics , Pancreatic Neoplasms/genetics , Retrospective Studies , Sensitivity and Specificity
10.
Mol Cytogenet ; 6(1): 38, 2013 Sep 20.
Article in English | MEDLINE | ID: mdl-24053112

ABSTRACT

BACKGROUND: Genomic microarrays have been used as the first-tier cytogenetic diagnostic test for patients with developmental delay/intellectual disability, autism spectrum disorders and/or multiple congenital anomalies. The use of SNP arrays has revealed regions of homozygosity in the genome which can lead to identification of uniparental disomy and parental consanguinity in addition to copy number variations. Consanguinity is associated with an increased risk of birth defects and autosomal recessive disorders. However, the frequency of parental consanguinity in children with developmental disabilities is unknown, and consanguineous couples may not be identified during doctor's visit or genetic counseling without microarray. RESULTS: We studied 607 proband pediatric patients referred for developmental disorders using a 4 × 180 K array containing both CGH and SNP probes. Using 720, 360, 180, and 90 Mb as the expected sizes of homozygosity for an estimated coefficient of inbreeding (F) 1/4, 1/8, 1/16, 1/32, parental consanguinity was detected in 21cases (3.46%). CONCLUSION: Parental consanguinity is not uncommon in children with developmental problems in our study population, and can be identified by use of a combined CGH and SNP chromosome microarray. Identification of parental consanguinity in such cases can be important for further diagnostic testing.

11.
Pediatr Res ; 71(5): 583-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22322387

ABSTRACT

INTRODUCTION: Oxygen exposure plays an important role in the pathogenesis of bronchopulmonary dysplasia (BPD). The phosphodiesterase inhibitor pentoxifylline (PTX) has anti-inflammatory and antifibrotic effects in multiple organs. It was hypothesized that PTX would have a protective effect on hyperoxia-induced lung injury (HILI). METHODS: Newborn Sprague-Dawley rats were exposed to >95% oxygen (O(2)) and injected subcutaneously with normal saline (NS) or PTX (75 mg/kg) twice a day for 9 d. NS-injected, room air-exposed pups were controls. At days 4 and 9, lung tissue was collected to assess edema, antioxidant enzyme (AOE) activities, and vascular endothelial growth factor (VEGF) expression. At day 9, pulmonary macrophage infiltration, vascularization, and alveolarization were also examined. RESULTS: At day 9, treatment with PTX significantly increased survival from 54% to 88% during hyperoxia. Treatment with PTX significantly decreased lung edema and macrophage infiltration. PTX treatment increased lung AOE activities including those of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). Furthermore, PTX treatment also increased the gene expression of VEGF189 and VEGF165, increased VEGF protein expression, and improved pulmonary vascularization. DISCUSSION: These data indicate that the reduced lung edema and inflammation, increased AOE activities, and improved vascularization may be responsible for the improved survival with PTX during hyperoxia. PTX may be a potential therapy in reducing some of the features of BPD in preterm newborns.


Subject(s)
Hyperoxia/complications , Lung Injury/prevention & control , Pentoxifylline/therapeutic use , Phosphodiesterase Inhibitors/therapeutic use , Animals , Animals, Newborn , Enzymes/metabolism , Female , Lung Injury/etiology , Lung Injury/pathology , Macrophages/pathology , Pregnancy , Pulmonary Edema/prevention & control , Rats , Rats, Sprague-Dawley , Vascular Endothelial Growth Factor A/metabolism
12.
Pediatr Res ; 65(4): 381-6, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19127219

ABSTRACT

The Smad2/3 pathway plays a key role in mediating TGF-beta1 inhibition of branching morphogenesis and induction of connective tissue growth factor (CTGF) expression in embryonic lungs. Because a number of cell-specific interactions have been described between TGF-beta1-driven Smad signaling and the c-Jun N-terminal kinase (JNK) pathway, we have investigated the effects of JNK inhibition on TGF-beta1 activation of Smad2, inhibition of branching, induction of CTGF expression, and apoptosis in mouse embryonic lung explants. Mouse embryonic day 12.5 (E12.5) lung explants were treated with TGF-beta1 in the presence or absence of a specific pharmacologic JNK inhibitor (SP600125) and a specific JNK peptide inhibitor (JNKI). We found that TGF-beta1 activated the JNK pathway by stimulating c-Jun phosphorylation, which was blocked by JNK inhibitors. Treatment with SP600125 stimulated Smad2 phosphorylation and enhanced TGF-beta1-induced Smad2 phosphorylation. Treatment with JNK inhibitors also decreased normal branching morphogenesis and induced CTGF expression as well as augmented TGF-beta1 inhibition of branching and induction of CTGF expression. Furthermore, JNK inhibition-induced apoptosis. Our results demonstrate that inhibition of the JNK pathway promotes TGF-beta1-driven Smad2 responses in lung branching morphogenesis. These data suggest that the JNK pathway may antagonize TGF-beta1 dependent Smad2 signaling during mouse embryonic lung development.


Subject(s)
Anthracenes/pharmacology , JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors , Lung/drug effects , Peptides/pharmacology , Protein Kinase Inhibitors/pharmacology , Signal Transduction/drug effects , Smad2 Protein/metabolism , Transforming Growth Factor beta1/metabolism , Animals , Apoptosis/drug effects , Connective Tissue Growth Factor/metabolism , Gene Expression Regulation, Developmental/drug effects , Gestational Age , JNK Mitogen-Activated Protein Kinases/metabolism , Lung/embryology , Lung/enzymology , Mice , Morphogenesis/drug effects , Phosphorylation , Proto-Oncogene Proteins c-jun/metabolism , Time Factors , Tissue Culture Techniques , Transforming Growth Factor beta1/genetics
13.
Neonatology ; 95(2): 132-40, 2009.
Article in English | MEDLINE | ID: mdl-18776727

ABSTRACT

BACKGROUND: Acute episodes of hypoxemia in ventilated preterm infants are triggered by changes in ventilation, lung volume (LV) and respiratory system compliance (C(RS)) that are not prevented by conventional synchronized intermittent mandatory ventilation (SIMV). OBJECTIVE: To assess in a rabbit model of episodic hypoxemia the individual and combined efficacy of targeted tidal volume (V(T)) and minute ventilation (V'(E)) by automatic adjustment of peak inspiratory pressure (PIP) and ventilator rate, respectively. METHODS: Six young New Zealand white rabbits were ventilated with SIMV, targeted V(T), targeted V'(E), and combined targeted V'(E) + V(T) in random sequence. Hypoxemia episodes were induced by apnea alone or by apnea combined with a reduction in LV and C(RS). Apnea was induced by a bolus of propofol. The reduction in LV and C(RS) was induced by chest compression with a cuff. PaO(2) and PaCO(2) were measured continuously by an indwelling arterial electrode. RESULTS: During SIMV, apnea caused a decrease in ventilation and PaO(2). This was attenuated during targeted V'(E) and targeted V'(E) + V(T). Apnea plus a reduction in LV and C(RS) caused a greater decrease in ventilation and PaO(2) during SIMV. These changes were attenuated during targeted V(T) and targeted V'(E). The attenuation was more pronounced during targeted V'(E) + V(T). CONCLUSION: In this animal model, targeted V'(E) was effective in reducing hypoxemia caused by apnea. When apnea was accompanied by a reduction in LV and C(RS), the combined adjustment of PIP and ventilator rate was more effective than each individually. This combined strategy may be effective in ameliorating acute episodes of hypoxemia in preterm infants but this remains to be proven.


Subject(s)
Hypoxia/physiopathology , Hypoxia/therapy , Intermittent Positive-Pressure Ventilation/methods , Pulmonary Ventilation/physiology , Respiratory Mechanics/physiology , Animals , Apnea/chemically induced , Apnea/complications , Apnea/physiopathology , Calibration , Disease Models, Animal , Hypoxia/etiology , Lung/physiopathology , Lung Compliance/physiology , Pressure/adverse effects , Propofol/pharmacology , Rabbits , Tidal Volume/physiology
14.
Pediatr Res ; 63(3): 245-50, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18287961

ABSTRACT

High tidal volume (V(T)) ventilation plays a key role in ventilator induced lung injury and bronchopulmonary dysplasia. However, little is known about the effect of high V(T) on expression of growth factors that are critical to lung development. In a previous study, we demonstrated that connective tissue growth factor (CTGF) inhibits branching morphogenesis. In this study, we investigated the effect of high V(T) on CTGF expression in newborn rat lungs. Newborn rats were ventilated with normal V(T) (10 mL/kg) or high V(T) (25 mL/kg) for 6 h. Nonventilated animals served as controls. We found that high V(T) upregulated CTGF expression. To identify the potential signaling pathways mediating high V(T) induction of CTGF, newborn rats were ventilated with high V(T) for 1 or 3 h. Temporal expression of TGF-betas, p-Smad2, Smad7, and CTGF was analyzed. High V(T) ventilation did not change gene expression of TGF-betas and Smad7 but induced rapid and sustained expression of p-Smad2 that precedes increased CTGF expression. CTGF and p-Smad2 were localized in bronchiolar epithelial cells, alveolar walls and septa. These data suggest that high V(t) ventilation activates the Smad2 pathway, which may be responsible for downstream induction of CTGF expression in newborn rat lungs.


Subject(s)
Immediate-Early Proteins/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Lung Diseases/metabolism , Lung/metabolism , Positive-Pressure Respiration/adverse effects , Signal Transduction , Smad2 Protein/metabolism , Tidal Volume , Animals , Animals, Newborn , Connective Tissue Growth Factor , Immediate-Early Proteins/genetics , Intercellular Signaling Peptides and Proteins/genetics , Interleukin-6/genetics , Interleukin-6/metabolism , Lung/growth & development , Lung/pathology , Lung/physiopathology , Lung Diseases/etiology , Lung Diseases/pathology , Lung Diseases/physiopathology , Phosphorylation , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Smad7 Protein/metabolism , Time Factors , Transforming Growth Factor beta/metabolism , Tumor Necrosis Factor-alpha , Up-Regulation
15.
Am J Respir Cell Mol Biol ; 36(5): 552-61, 2007 May.
Article in English | MEDLINE | ID: mdl-17197570

ABSTRACT

Transforming growth factor-beta1 (TGF-beta1) has been implicated as a major negative regulator of lung branching morphogenesis. Since connective tissue growth factor (CTGF) is a downstream mediator of TGF-beta1 effects on mesenchymal cells, we hypothesized that TGF-beta1 induces CTGF expression in mouse embryonic lung explants and that CTGF mediates TGF-beta1 inhibition of branching morphogenesis. We show that addition of TGF-beta1 to the serum-free medium of embryonic day (E)12.5 lung explant cultures inhibited branching morphogenesis and induced CTGF mRNA expression in time- and dose-dependent manners. In contrast to basal endogenous CTGF protein, which was exclusively localized in the distal airway epithelium, TGF-beta1-induced CTGF protein was localized in both the epithelium and the mesenchyme. Addition of exogenous CTGF to culture medium directly inhibited branching morphogenesis. To identify the signal transduction pathway through which TGF-beta1 induces CTGF, we used SB431542, a specific inhibitor for TGF-beta type I receptor (TbetaRI)/ALK-5 to block TGF-beta1-induced Smad2/3 phosphorylation. Consequently, SB431542 stimulated normal branching morphogenesis and blocked TGF-beta1 inhibition of branching. Furthermore, SB-431542 blocked both endogenous and TGF-beta1-induced expression of CTGF mRNA and protein. These results demonstrate for the first time that TGF-beta1 induces CTGF expression in mouse embryonic lung explants, that CTGF inhibits branching morphogenesis, and that both endogenous and TGF-beta1-induced CTGF expression are mediated by the TbetaRI/ALK-5-dependent Smad2 signaling pathway.


Subject(s)
Activin Receptors, Type I/metabolism , Gene Expression Regulation/drug effects , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Lung/embryology , Lung/metabolism , Receptors, Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta1/pharmacology , Activin Receptors, Type I/antagonists & inhibitors , Animals , Benzamides/pharmacology , Connective Tissue Growth Factor , Cycloheximide/pharmacology , Dioxoles/pharmacology , Female , Immediate-Early Proteins/biosynthesis , Intercellular Signaling Peptides and Proteins/biosynthesis , Lung/cytology , Lung/drug effects , Male , Mice , Morphogenesis/drug effects , Phosphorylation/drug effects , Protein Biosynthesis/drug effects , Protein Serine-Threonine Kinases , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, Transforming Growth Factor-beta Type I , Receptors, Transforming Growth Factor beta/antagonists & inhibitors , Smad2 Protein/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...