HMGA1 induces FGF19 to drive pancreatic carcinogenesis and stroma formation.

High mobility group A1 (HMGA1) chromatin regulators are upregulated in diverse tumors where they portend adverse outcomes, although how they function in cancer remains unclear. Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors characterized by dense desmoplastic stroma composed predominantly of cancer-associated fibroblasts and fibrotic tissue. Here, we uncover an epigenetic program whereby HMGA1 upregulates FGF19 during tumor progression and stroma formation. HMGA1 deficiency disrupts oncogenic properties in vitro while impairing tumor inception and progression in KPC mice and subcutaneous or orthotopic models of PDAC. RNA sequencing revealed HMGA1 transcriptional networks governing proliferation and tumor-stroma interactions, including the FGF19 gene. HMGA1 directly induces FGF19 expression and increases its protein secretion by recruiting active histone marks (H3K4me3, H3K27Ac). Surprisingly, disrupting FGF19 via gene silencing or the FGFR4 inhibitor BLU9931 recapitulates most phenotypes observed with HMGA1 deficiency, decreasing tumor growth and formation of a desmoplastic stroma in mouse models of PDAC. In human PDAC, overexpression of HMGA1 and FGF19 defines a subset of tumors with extremely poor outcomes. Our results reveal what we believe is a new paradigm whereby HMGA1 and FGF19 drive tumor progression and stroma formation, thus illuminating FGF19 as a rational therapeutic target for a molecularly defined PDAC subtype.

Effect of Hypoxia in the Transcriptomic Profile of Lung Fibroblasts from Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an aging-associated disease characterized by exacerbated extracellular matrix deposition that disrupts oxygen exchange. Hypoxia and its transcription factors (HIF-1α and 2α) influence numerous circuits that could perpetuate fibrosis by increasing myofibroblasts differentiation and by promoting extracellular matrix accumulation. Therefore, this work aimed to elucidate the signature of hypoxia in the transcriptomic circuitry of IPF-derived fibroblasts. To determine this transcriptomic signature, a gene expression analysis with six lines of lung fibroblasts under normoxia or hypoxia was performed: three cell lines were derived from patients with IPF, and three were from healthy donors, a total of 36 replicates. We used the Clariom D platform, which allows us to evaluate a huge number of transcripts, to analyze the response to hypoxia in both controls and IPF. The control's response is greater by the number of genes and complexity. In the search for specific genes responsible for the IPF fibroblast phenotype, nineteen dysregulated genes were found in lung fibroblasts from IPF patients in hypoxia (nine upregulated and ten downregulated). In this sense, the signaling pathways revealed to be affected in the pulmonary fibroblasts of patients with IPF may represent an adaptation to chronic hypoxia.

Antitumor Therapy under Hypoxic Microenvironment by the Combination of 2-Methoxyestradiol and Sodium Dichloroacetate on Human Non-Small-Cell Lung Cancer.

A hypoxic microenvironment is a hallmark in different types of tumors; this phenomenon participates in a metabolic alteration that confers resistance to treatments. Because of this, it was proposed that a combination of 2-methoxyestradiol (2-ME) and sodium dichloroacetate (DCA) could reduce this alteration, preventing proliferation through the reactivation of aerobic metabolism in lung adenocarcinoma cell line (A549). A549 cells were cultured in a hypoxic chamber at 1% O2 for 72 hours to determine the effect of this combination on growth, migration, and expression of hypoxia-inducible factors (HIFs) by immunofluorescence. The effect in the metabolism was evaluated by the determination of glucose/glutamine consumption and the lactate/glutamate production. The treatment of 2-ME (10 µM) in combination with DCA (40 mM) under hypoxic conditions showed an inhibitory effect on growth and migration. Notably, this reduction could be attributed to 2-ME, while DCA had a predominant effect on metabolic activity. Moreover, this combination decreases the signaling of HIF-3α and partially HIF-1α but not HIF-2α. The results of this study highlight the antitumor activity of the combination of 2-ME 10 µl/DCA 40 mM, even in hypoxic conditions.

CX3CL1 and CX3CR1 could be a relevant molecular axis in the pathophysiology of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis is a chronic and progressive disease of unknown cause. It is characterized by the aberrant activation of the bronchioalveolar epithelium, the formation of fibroblast foci and the excessive production extracellular matrix. The cellular and molecular mechanisms that contribute to the pathobiology of the disease are unclear. The CX3CL1-CX3CR1 axis regulates cellular responses that are known to be relevant in IPF, such as proliferation and collagen production. In this study, we characterize for the first time the expression of CX3CL1 and its receptor in lung tissue from patients with IPF; and its effect on collagen production in IPF fibroblasts. We found that CX3CL1-CX3CR1 axis has a modified expression in the lung tissue, importantly this axis is expressed on fibroblasts, and CX3CL1 decreased the collagen production in pulmonary fibroblasts derived from IPF patients.

Risk factors associated with the detection of pulmonary emphysema in older asymptomatic respiratory subjects.

BACKGROUND: Several lung structural and functional abnormalities may occur associated with aging, including emphysema. In this study, we evaluated the frequency and risk factors associated with emphysema in respiratory asymptomatic individuals enrolled in our Lung Aging Program. From a cohort of 687 subjects, we found by high-resolution computed tomography (HRCT) 29 individuals (4%) with emphysematous changes that were compared with 87 controls (3:1) randomly selected from the same cohort. METHODS: This was a transversal, observational, case-control study where we examined demographics and functional characteristics, as well as telomere length and serum Klotho concentration, two conditions that have been associated with aging and some aging-associated diseases including emphysema. RESULTS: Individuals with subclinical pulmonary emphysema were older (72 ± 9 versus 67 ± 6 years), and primarily smoker males with low body mass index. Despite that they were asymptomatic, two of them exhibited a decrease of forced expiratory volume in 1 s (FEV1), with a lower FEV1/FVC suggesting airway obstruction. Cigarette smoking (OR = 5.43, CI95% 1.8-16.7), family history of lung disease (OR = 4.32, CI95% 1.0-19.0) and lower body mass index (OR 7.22, CI95% 1.2-3.5) were risk factors for the development of lung emphysematous changes. No association was found with telomere length and Klotho serum concentration. CONCLUSION: Our findings reveal that a small but important percentage of older people without respiratory symptoms, present pulmonary emphysema and indicate that smoking exposure and genetic background may contribute to etiological factors.

Impaired autophagic activity and ATG4B deficiency are associated with increased endoplasmic reticulum stress-induced lung injury.

Aging is the main risk factor for the development of idiopathic pulmonary fibrosis (IPF), a progressive and usually lethal lung disorder. Although the pathogenic mechanisms are uncertain, endoplasmic reticulum (ER) stress and impaired proteostasis that have been linked with aging are strongly associated with the pathogenesis of IPF. Using the Atg4b-deficient mice as a model, that partially reproduces the autophagy deficient conditions reported in aging and IPF lungs, we show for the first time how autophagy impairment and ER stress induction, contribute simultaneously to development of lung fibrosis in vivo. Increased expression of ER stress markers, inflammation and apoptosis of alveolar epithelial cells were observed in Atg4b-deficient mice compared to WT mice, when treated with the ER stress inducer tunicamycin. After tunicamycin treatment, Atg4b null lungs showed accumulation of its substrate LC3-I, demonstrating that these mice failed to induce autophagy despite the ER stress conditions. We also showed that compromised autophagy in lungs from Atg4b null mice is associated with exacerbated lung damage, epithelial apoptosis and the development of lung fibrosis at 21 days after tunicamycin treatment. Our findings indicate that ATG4B protein and autophagy are essential to mitigate ER stress and to prevent tunicamycin-induced epithelial apoptosis and lung fibrosis.

Upregulation and Nuclear Location of MMP28 in Alveolar Epithelium of Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive aging-associated disease of unknown etiology. A growing body of evidence indicates that aberrant activated alveolar epithelial cells induce the expansion and activation of the fibroblast population, leading to the destruction of the lung architecture. Some matrix metalloproteinases (MMPs) are upregulated in IPF, indicating that they may be important in the pathogenesis and/or progression of IPF. In the present study, we examined the expression of MMP28 in this disease and evaluated its functional effects in two alveolar epithelial cell lines and in human primary bronchial epithelial cells. We found that the enzyme is expressed in bronchial (apical and cytoplasmic localization) and alveolar (cytoplasmic and nuclear localization) epithelial cells in two different groups of patients with IPF. In vitro MMP28 epithelial silencing decreased the proliferation rate and delayed wound closing, whereas overexpression showed opposite effects, protecting from apoptosis and enhanced epithelial-mesenchymal transition. Our findings demonstrate that MMP28 is upregulated in epithelial cells from IPF lungs, where it may play a role in increasing the proliferative and migratory phenotype in a catalysis-dependent manner.

Essential role for the ATG4B protease and autophagy in bleomycin-induced pulmonary fibrosis.

Autophagy is a critical cellular homeostatic process that controls the turnover of damaged organelles and proteins. Impaired autophagic activity is involved in a number of diseases, including idiopathic pulmonary fibrosis suggesting that altered autophagy may contribute to fibrogenesis. However, the specific role of autophagy in lung fibrosis is still undefined. In this study, we show for the first time, how autophagy disruption contributes to bleomycin-induced lung fibrosis in vivo using an Atg4b-deficient mouse as a model. Atg4b-deficient mice displayed a significantly higher inflammatory response at 7 d after bleomycin treatment associated with increased neutrophilic infiltration and significant alterations in proinflammatory cytokines. Likewise, we found that Atg4b disruption resulted in augmented apoptosis affecting predominantly alveolar and bronchiolar epithelial cells. At 28 d post-bleomycin instillation Atg4b-deficient mice exhibited more extensive and severe fibrosis with increased collagen accumulation and deregulated extracellular matrix-related gene expression. Together, our findings indicate that the ATG4B protease and autophagy play a crucial role protecting epithelial cells against bleomycin-induced stress and apoptosis, and in the regulation of the inflammatory and fibrotic responses.

FEV1 inversely correlates with metalloproteinases 1, 7, 9 and CRP in COPD by biomass smoke exposure.

BACKGROUND: Matrix metalloproteinases (MMPs) and C-reactive protein (CRP) are involved in chronic obstructive pulmonary disease (COPD) pathogenesis. The aim of the present work was to determine plasma concentrations of MMPs and CRP in COPD associated to biomass combustion exposure (BE) and tobacco smoking (TS). METHODS: Pulmonary function tests, plasma levels of MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP were measured in COPD associated to BE (n = 40) and TS (n =40) patients, and healthy non-smoking (NS) healthy women (controls, n = 40). RESULTS: Plasma levels of MMP-1, MMP-7, MMP-9, and MMP-9/TIMP-1 and CRP were higher in BE and TS than in the NS healthy women (p <0.01). An inverse correlation between MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP plasma concentrations and FEV1 was observed. CONCLUSIONS: Increase of MMPs and CRP plasma concentrations in BE suggests a systemic inflammatory phenomenon similar to that observed in COPD associated to tobacco smoking, which may also play a role in COPD pathogenesis.

Matrix metalloproteinase (MMP)-1 induces lung alveolar epithelial cell migration and proliferation, protects from apoptosis, and represses mitochondrial oxygen consumption.

Idiopathic pulmonary fibrosis is a devastating lung disorder of unknown etiology. Although its pathogenesis is unclear, considerable evidence supports an important role of aberrantly activated alveolar epithelial cells (AECs), which produce a large variety of mediators, including several matrix metalloproteases (MMPs), which participate in fibroblast activation and lung remodeling. MMP-1 has been shown to be highly expressed in AECs from idiopathic pulmonary fibrosis lungs although its role is unknown. In this study, we explored the role of MMP-1 in several AECs functions. Mouse lung epithelial cells (MLE12) transfected with human Mmp-1 showed significantly increased cell growth and proliferation at 36 and 48 h of culture (p < 0.01). Also, MMP-1 promoted MLE12 cell migration through collagen I, accelerated wound closing, and protected cells from staurosporine- and bleomycin-induced apoptosis compared with mock cells (p < 0.01). MLE12 cells expressing human MMP-1 showed a significant repression of oxygen consumption ratio compared with the cells with the empty vector. As under hypoxic conditions hypoxia-inducible factor-1α (HIF-1α) mediates a transition from oxidative to glycolytic metabolism, we analyzed activation of HIF-1α. Ηigher activation of this factor was detected in MMP-1-transfected cells under normoxia and hypoxia. Likewise, a significant decrease of both total and mitochondrial reactive oxygen species was observed in MMP-1-transfected cells. Paralleling these findings, attenuation of MMP-1 expression by shRNA in A549 (human) AECs markedly reduced proliferation and migration (p < 0.01) and increased the oxygen consumption ratio. These findings indicate that epithelial expression of MMP-1 inhibits mitochondrial function, increases HIF-1α expression, decreases reactive oxygen species production, and contributes to a proliferative, migratory, and anti-apoptotic AEC phenotype.

Hypermethylation-mediated silencing of p14(ARF) in fibroblasts from idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease of unknown etiology. A conspicuous feature is the formation and persistence of fibroblastic/myofibroblastic foci throughout the lung parenchyma. Mechanisms remain unknown, but data indicate that fibroblasts acquire an antiapoptotic phenotype. We hypothesized that transcriptional silencing of proapoptotic genes may be implicated, and accordingly we evaluated the epigenetic regulation of p14(ARF). The expression of p14(ARF) was analyzed by RT-PCR in IPF (n = 8) and normal derived fibroblasts (n = 4) before and after treatment with 5-aza-2'-deoxycytidine (5-aza) and trichostatin A (TSA). p14(ARF) gene promoter methylation was determined by methylation-specific PCR (MS-PCR) and by DNA digestion with endonuclease McrBc, which cleaves 50% of methylated CpG. Apoptosis was evaluated by Annexin-V and nuclear staining. p14(ARF) expression was significantly decreased in four of the eight IPF fibroblasts lines, which was restored after 5-aza treatment. No changes were found with TSA. MS-PCR of bisulfite-treated genomic DNA showed a correlation between the reduced expression of p14(ARF) and the presence of hypermethylated promoter. No amplification was observed in the DNA treated with the McrBc enzyme, corroborating promoter hypermethylation. p14(ARF)-hypermethylated IPF fibroblasts were significantly more resistant to staurosporine-and S-nitrosoglutathione-induced apoptosis compared with normal and nonmethylated IPF fibroblasts (P < 0.01) and showed reduced levels of p53. Resistance to apoptosis was provoked in fibroblasts when p14(ARF) expression was inhibited by siRNA (P < 0.05). These findings demonstrate that many IPF fibroblasts have reduced expression of the proapoptotic p14(ARF) attributable to promoter hypermethylation and indicate that epigenetic mechanisms may underlie their resistance to apoptosis.

Up-regulation and profibrotic role of osteopontin in human idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal disorder characterized by fibroproliferation and excessive accumulation of extracellular matrix in the lung. METHODS AND FINDINGS: Using oligonucleotide arrays, we identified osteopontin as one of the genes that significantly distinguishes IPF from normal lungs. Osteopontin was localized to alveolar epithelial cells in IPF lungs and was also significantly elevated in bronchoalveolar lavage from IPF patients. To study the fibrosis-relevant effects of osteopontin we stimulated primary human lung fibroblasts and alveolar epithelial cells (A549) with recombinant osteopontin. Osteopontin induced a significant increase of migration and proliferation in both fibroblasts and epithelial cells. Epithelial growth was inhibited by the pentapeptide Gly-Arg-Gly-Asp-Ser (GRGDS) and antibody to CD44, while fibroproliferation was inhibited by GRGDS and antibody to alphavbeta3 integrin. Fibroblast and epithelial cell migration were inhibited by GRGDS, anti-CD44, and anti-alphavbeta3. In fibroblasts, osteopontin up-regulated tissue inhibitor of metalloprotease-1 and type I collagen, and down-regulated matrix metalloprotease-1 (MMP-1) expression, while in A549 cells it caused up-regulation of MMP-7. In human IPF lungs, osteopontin colocalized with MMP-7 in alveolar epithelial cells, and application of weakest link statistical models to microarray data suggested a significant interaction between osteopontin and MMP-7. CONCLUSIONS: Our results provide a potential mechanism by which osteopontin secreted from the alveolar epithelium may exert a profibrotic effect in IPF lungs and highlight osteopontin as a potential target for therapeutic intervention in this incurable disease.

Partograma con curvas de alerta en pacientes de la altura / Partogram with alert curves in high altitude patient

Objetivo: Describir la curva de alerta en parturientas de la altura. Diseño: Se realiza un estudio descriptivo, explicativo y prospectivo de corte transversal de enero a mayo de 1997. Pacientes: 400 parturientas nulíparas y multíparas a término, con presentación cefálica atendidas en el Hospital Víctor Ramos Guardia de Huaraz, seleccionadas con criterios de inclusión y que cursaron con trabajo de parto normal sin uso medicamentoso pre e intra parto. Fueron clasificadas en cuatro grupos de acuerdo al CLAP, cuidando de trazar la curva de alerta a partir de 4 cm de dilatación . El análisis estadístico, procedimiento de datos y la obtención de resultados con programas de EPIINFO 5, calculando el percentil 10 y construyéndose la curva a la izquierda con respecto a la curva del CLAP y aún más a la izquierda si comparamos con la curva a nivel del mar (HAMA), atribuyéndose este comportamiento al estado nutricional y al umbral doloroso de mujeres de la altura. Conclusión: La curva de alerta en parturientas de la altura presenta tiempos menores de dilatación. Palabras clave: Partograma, gestantes en altura.