Aberrant TIMP-1 production in tumor-associated fibroblasts drives the selective benefits of nintedanib in lung adenocarcinoma.

The fibrotic tumor microenvironment is a pivotal therapeutic target. Nintedanib, a clinically approved multikinase antifibrotic inhibitor, is effective against lung adenocarcinoma (ADC) but not squamous cell carcinoma (SCC). Previous studies have implicated the secretome of tumor-associated fibroblasts (TAFs) in the selective effects of nintedanib in ADC, but the driving factor(s) remained unidentified. Here we examined the role of tissue inhibitor of metalloproteinase-1 (TIMP-1), a tumor-promoting cytokine overproduced in ADC-TAFs. To this aim, we combined genetic approaches with in vitro and in vivo preclinical models based on patient-derived TAFs. Nintedanib reduced TIMP-1 production more efficiently in ADC-TAFs than SCC-TAFs through a SMAD3-dependent mechanism. Cell culture experiments indicated that silencing TIMP1 in ADC-TAFs abolished the therapeutic effects of nintedanib on cancer cell growth and invasion, which were otherwise enhanced by the TAF secretome. Consistently, co-injecting ADC cells with TIMP1-knockdown ADC-TAFs into immunocompromised mice elicited a less effective reduction of tumor growth and invasion under nintedanib treatment compared to tumors bearing unmodified fibroblasts. Our results unveil a key mechanism underlying the selective mode of action of nintedanib in ADC based on the excessive production of TIMP-1 in ADC-TAFs. We further pinpoint reduced SMAD3 expression and consequent limited TIMP-1 production in SCC-TAFs as key for the resistance of SCC to nintedanib. These observations strongly support the emerging role of TIMP-1 as a critical regulator of therapy response in solid tumors.

miRNAs Related to Immune Checkpoint Inhibitor Response: A Systematic Review.

The advent of immune checkpoint inhibitors (ICIs) has represented a breakthrough in the treatment of many cancers, although a high number of patients fail to respond to ICIs, which is partially due to the ability of tumor cells to evade immune system surveillance. Non-coding microRNAs (miRNAs) have been shown to modulate the immune evasion of tumor cells, and there is thus growing interest in elucidating whether these miRNAs could be targetable or proposed as novel biomarkers for prognosis and treatment response to ICIs. We therefore performed an extensive literature analysis to evaluate the clinical utility of miRNAs with a confirmed direct relationship with treatment response to ICIs. As a result of this systematic review, we have stratified the miRNA landscape into (i) miRNAs whose levels directly modulate response to ICIs, (ii) miRNAs whose expression is modulated by ICIs, and (iii) miRNAs that directly elicit toxic effects or participate in immune-related adverse events (irAEs) caused by ICIs.

The Role of Aryl Hydrocarbon Receptor in the Endothelium: A Systematic Review.

Activation of the aryl hydrocarbon receptor (AhR) has been shown to be important in physiological processes other than detoxification, including vascular homeostasis. Although AhR is highly expressed in the endothelium, its function has been poorly studied. This systematic review aims to summarise current knowledge on the AhR role in the endothelium and its cardiovascular implications. We focus on endogenous AhR agonists, such as some uremic toxins and other agonists unrelated to environmental pollutants, as well as studies using AhR knockout models. We conclude that AhR activation leads to vascular oxidative stress and endothelial dysfunction and that blocking AhR signalling could provide a new target for the treatment of vascular disorders such as cardiovascular complications in patients with chronic kidney disease or pulmonary arterial hypertension.

Matrix Metalloproteinases and Their Inhibitors in Pulmonary Fibrosis: EMMPRIN/CD147 Comes into Play.

Pulmonary fibrosis (PF) is characterized by aberrant extracellular matrix (ECM) deposition, activation of fibroblasts to myofibroblasts and parenchymal disorganization, which have an impact on the biomechanical traits of the lung. In this context, the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) is lost. Interestingly, several MMPs are overexpressed during PF and exhibit a clear profibrotic role (MMP-2, -3, -8, -11, -12 and -28), but a few are antifibrotic (MMP-19), have both profibrotic and antifibrotic capacity (MMP7), or execute an unclear (MMP-1, -9, -10, -13, -14) or unknown function. TIMPs are also overexpressed in PF; hence, the modulation and function of MMPs and TIMP are more complex than expected. EMMPRIN/CD147 (also known as basigin) is a transmembrane glycoprotein from the immunoglobulin superfamily (IgSF) that was first described to induce MMP activity in fibroblasts. It also interacts with other molecules to execute non-related MMP aactions well-described in cancer progression, migration, and invasion. Emerging evidence strongly suggests that CD147 plays a key role in PF not only by MMP induction but also by stimulating fibroblast myofibroblast transition. In this review, we study the structure and function of MMPs, TIMPs and CD147 in PF and their complex crosstalk between them.

Interleukin-1ß Modulation of the Mechanobiology of Primary Human Pulmonary Fibroblasts: Potential Implications in Lung Repair.

Pro-inflammatory cytokines like interleukin-1ß (IL-1ß) are upregulated during early responses to tissue damage and are expected to transiently compromise the mechanical microenvironment. Fibroblasts are key regulators of tissue mechanics in the lungs and other organs. However, the effects of IL-1ß on fibroblast mechanics and functions remain unclear. Here we treated human pulmonary fibroblasts from control donors with IL-1ß and used Atomic Force Microscopy to unveil that IL-1ß significantly reduces the stiffness of fibroblasts concomitantly with a downregulation of filamentous actin (F-actin) and alpha-smooth muscle (α-SMA). Likewise, COL1A1 mRNA was reduced, whereas that of collagenases MMP1 and MMP2 were upregulated, favoring a reduction of type-I collagen. These mechanobiology changes were functionally associated with reduced proliferation and enhanced migration upon IL-1ß stimulation, which could facilitate lung repair by drawing fibroblasts to sites of tissue damage. Our observations reveal that IL-1ß may reduce local tissue rigidity by acting both intracellularly and extracellularly through the downregulation of fibroblast contractility and type I collagen deposition, respectively. These IL-1ß-dependent mechanical effects may enhance lung repair further by locally increasing pulmonary tissue compliance to preserve normal lung distension and function. Moreover, our results support that IL-1ß provides innate anti-fibrotic protection that may be relevant during the early stages of lung repair.

Role of obesity in the release of extracellular nucleosomes in acute pancreatitis: a clinical and experimental study.

BACKGROUND/OBJECTIVES: A high body mass index increases the risk of severe pancreatitis and associated mortality. Our aims were: (1) To determine whether obesity affects the release of extracellular nucleosomes in patients with pancreatitis; (2) To determine whether pancreatic ascites confers lipotoxicity and triggers the release of extracellular nucleosomes in lean and obese rats. METHODS: DNA and nucleosomes were determined in plasma from patients with mild or moderately severe acute pancreatitis either with normal or high body mass index (BMI). Lipids from pancreatic ascites from lean and obese rats were analyzed and the associated toxicity measured in vitro in RAW 264.7 macrophages. The inflammatory response, extracellular DNA and nucleosomes were determined in lean or obese rats with pancreatitis after peritoneal lavage. RESULTS: Nucleosome levels in plasma from obese patients with mild pancreatitis were higher than in normal BMI patients; these levels markedly increased in obese patients with moderately severe pancreatitis vs. those with normal BMI. Ascites from obese rats exhibited high levels of palmitic, oleic, stearic, and arachidonic acids. Necrosis and histone 4 citrullination-marker of extracellular traps-increased in macrophages incubated with ascites from obese rats but not with ascites from lean rats. Peritoneal lavage abrogated the increase in DNA and nucleosomes in plasma from lean or obese rats with pancreatitis. It prevented fat necrosis and induction of HIF-related genes in lung. CONCLUSIONS: Extracellular nucleosomes are intensely released in obese patients with acute pancreatitis. Pancreatitis-associated ascitic fluid triggers the release of extracellular nucleosomes in rats with severe pancreatitis.

Epithelial contribution to the profibrotic stiff microenvironment and myofibroblast population in lung fibrosis.

The contribution of epithelial-to-mesenchymal transition (EMT) to the profibrotic stiff microenvironment and myofibroblast accumulation in pulmonary fibrosis remains unclear. We examined EMT-competent lung epithelial cells and lung fibroblasts from control (fibrosis-free) donors or patients with idiopathic pulmonary fibrosis (IPF), which is a very aggressive fibrotic disorder. Cells were cultured on profibrotic conditions including stiff substrata and TGF-ß1, and analyzed in terms of morphology, stiffness, and expression of EMT/myofibroblast markers and fibrillar collagens. All fibroblasts acquired a robust myofibroblast phenotype on TGF-ß1 stimulation. Yet IPF myofibroblasts exhibited higher stiffness and expression of fibrillar collagens than control fibroblasts, concomitantly with enhanced FAKY397 activity. FAK inhibition was sufficient to decrease fibroblast stiffness and collagen expression, supporting that FAKY397 hyperactivation may underlie the aberrant mechanobiology of IPF fibroblasts. In contrast, cells undergoing EMT failed to reach the values exhibited by IPF myofibroblasts in all parameters examined. Likewise, EMT could be distinguished from nonactivated control fibroblasts, suggesting that EMT does not elicit myofibroblast precursors either. Our data suggest that EMT does not contribute directly to the myofibroblast population, and may contribute to the stiff fibrotic microenvironment through their own stiffness but not their collagen expression. Our results also support that targeting FAKY397 may rescue normal mechanobiology in IPF.

Epigenetic Regulation of Early- and Late-Response Genes in Acute Pancreatitis.

Chromatin remodeling seems to regulate the patterns of proinflammatory genes. Our aim was to provide new insights into the epigenetic mechanisms that control transcriptional activation of early- and late-response genes in initiation and development of severe acute pancreatitis as a model of acute inflammation. Chromatin changes were studied by chromatin immunoprecipitation analysis, nucleosome positioning, and determination of histone modifications in promoters of proinflammatory genes in vivo in the course of taurocholate-induced necrotizing pancreatitis in rats and in vitro in rat pancreatic AR42J acinar cells stimulated with taurocholate or TNF-α. Here we show that the upregulation of early and late inflammatory genes rely on histone acetylation associated with recruitment of histone acetyltransferase CBP. Chromatin remodeling of early genes during the inflammatory response in vivo is characterized by a rapid and transient increase in H3K14ac, H3K27ac, and H4K5ac as well as by recruitment of chromatin-remodeling complex containing BRG-1. Chromatin remodeling in late genes is characterized by a late and marked increase in histone methylation, particularly in H3K4. JNK and p38 MAPK drive the recruitment of transcription factors and the subsequent upregulation of early and late inflammatory genes, which is associated with nuclear translocation of the early gene Egr-1 In conclusion, specific and strictly ordered epigenetic markers such as histone acetylation and methylation, as well as recruitment of BRG-1-containing remodeling complex are associated with the upregulation of both early and late proinflammatory genes in acute pancreatitis. Our findings highlight the importance of epigenetic regulatory mechanisms in the control of the inflammatory cascade.

[Estimation of the daily nutrients distribution in the Spanish standard diet]. / ESTIMACIÓN DE LA DISTRIBUCIÓN DIARIA DE NUTRIENTES EN LA DIETA ESTÁNDAR EN ESPAÑA.

Based on the raw data from the Spanish intake, have made the necessary changes and groupings to establish nutritional content per serving as percentages, regarding the total daily intake of each individual surveyed (n = 3000). Also, it was found the effect of the rating factors (sex, age and location) on the distribution of these percentages. The result indicates that individuals below 25 year should be considered as different groups, front those above that age; and locality effect (treated as random factor rather than fixed) causes differences in the distribution of nutrients between food daily intakes. However, the sex was was not relevant to the anecdotal footage found in statistically significant differences. Percentage distribution of individual nutrients between different food outlets is proposed.

A partir de datos de consumo alimentario de España se han realizado las transformaciones y agrupaciones necesarias para establecer los contenidos nutricionales por toma, en forma de porcentajes, respecto a la ingesta total diaria de cada individuo encuestado (n = 3000). Así mismo, se ha comprobado el efecto de los factores de clasificación (sexo, edad y localidad) sobre la distribución de dichos porcentajes. El resultado del estudio estadístico indica que se deben considerar como grupos diferentes los individuos por debajo de 25 años respecto a los que superan esa edad y que el efecto localidad (entendido como aleatorio y no como fijo) ocasiona diferencias en la distribución de nutrientes entre las tomas de alimentos del día. En cambio, el factor sexo no resultó relevante al encontrarse en tomas anecdóticas las diferencias estadísticamente significativas. Se propone una distribución porcentual de nutrientes concretos entre las diferentes tomas de alimentos.

Estimación de la distribución diaria de nutrientes en la dieta estándar en España / Estimation of the daily nutrients distribution in the Spanish standard diet

A partir de datos de consumo alimentario de España se han realizado las transformaciones y agrupaciones necesarias para establecer los contenidos nutricionales por toma, en forma de porcentajes, respecto a la ingesta total diaria de cada individuo encuestado (n = 3000). Así mismo, se ha comprobado el efecto de los factores de clasificación (sexo, edad y localidad) sobre la distribución de dichos porcentajes. El resultado del estudio estadístico indica que se deben considerar como grupos diferentes los individuos por debajo de 25 años respecto a los que superan esa edad y que el efecto localidad (entendido como aleatorio y no como fijo) ocasiona diferencias en la distribución de nutrientes entre las tomas de alimentos del día. En cambio, el factor sexo no resultó relevante al encontrarse en tomas anecdóticas las diferencias estadísticamente significativas. Se propone una distribución porcentual de nutrientes concretos entre las diferentes tomas de alimentos (AU)

Based on the raw data from the Spanish intake, have made the necessary changes and groupings to establish nutritional content per serving as percentages, regarding the total daily intake of each individual surveyed (n = 3000). Also, it was found the effect of the rating factors (sex, age and location) on the distribution of these percentages. The result indicates that individuals below 25 year should be considered as different groups, front those above that age; and locality effect (treated as random factor rather than fixed) causes differences in the distribution of nutrients between food daily intakes. However, the sex was not relevant to the anecdotal footage found in statistically significant differences. Percentage distribution of individual nutrients between different food outlets is proposed (AU)

Redox signaling in acute pancreatitis.

Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

Pancreatic ascites hemoglobin contributes to the systemic response in acute pancreatitis.

Upon hemolysis extracellular hemoglobin causes oxidative stress and cytotoxicity due to its peroxidase activity. Extracellular hemoglobin may release free hemin, which increases vascular permeability, leukocyte recruitment, and adhesion molecule expression. Pancreatitis-associated ascitic fluid is reddish and may contain extracellular hemoglobin. Our aim has been to determine the role of extracellular hemoglobin in the local and systemic inflammatory response during severe acute pancreatitis in rats. To this end we studied taurocholate-induced necrotizing pancreatitis in rats. First, extracellular hemoglobin in ascites and plasma was quantified and the hemolytic action of ascitic fluid was tested. Second, we assessed whether peritoneal lavage prevented the increase in extracellular hemoglobin in plasma during pancreatitis. Third, hemoglobin was purified from rat erythrocytes and administered intraperitoneally to assess the local and systemic effects of ascitic-associated extracellular hemoglobin during acute pancreatitis. Extracellular hemoglobin and hemin levels markedly increased in ascitic fluid and plasma during necrotizing pancreatitis. Peroxidase activity was very high in ascites. The peritoneal lavage abrogated the increase in extracellular hemoglobin in plasma. The administration of extracellular hemoglobin enhanced ascites; dramatically increased abdominal fat necrosis; upregulated tumor necrosis factor-α, interleukin-1ß, and interleukin-6 gene expression; and decreased expression of interleukin-10 in abdominal adipose tissue during pancreatitis. Extracellular hemoglobin enhanced the gene expression and protein levels of vascular endothelial growth factor (VEGF) and other hypoxia-inducible factor-related genes in the lung. Extracellular hemoglobin also increased myeloperoxidase activity in the lung. In conclusion, extracellular hemoglobin contributes to the inflammatory response in severe acute pancreatitis through abdominal fat necrosis and inflammation and by increasing VEGF and leukocyte infiltration into the lung.

[Bartonella henselae in children with regional adenitis treated in a Peruvian national hospital, 2012]. / Bartonella henselae en niños con adenitis regional atendidos en un hospital nacional del Perú, 2012.

In order to determine the frequency of seropositive cases of Bartonella henselae in children with regional adenitis treated in a national hospital in Peru, a cross-sectional study was conducted in 106 children with regional adenitis greater than 1 cm in diameter. The sample was selected from patients aged 5-11 years seen at the National Institute of Child Health for acute onset of regional adentitis, with more than five days of symptoms. B. henselae seropositivity was defined by indirect immunofluorescence test. We found that 86 children (81.1%) were positive for B.henselae. The median age of the patients was 7 years. In the bivariate analysis, the following associated factors were found: aged 5 years, history of fever, lymphadenopathy greater than 4 cm and reported contact with cat. In conclusion, children with regional adenitis treated in this national referral hospital showed a high frequency of positive serology for B. henselae.

Bartonella henselae en niños con adenitis regional atendidos en un hospital nacional del Perú, 2012 / Bartonella henselae in children with regional adenitis treated in a Peruvian national hospital, 2012

Con el objetivo de determinar la frecuencia de casos seropositivos a Bartonella henselae en niños con adenitis regional atendidos en un hospital nacional del Perú, se realizó un estudio trasversal en 106 niños con adenitis regional mayor de 1 cm de diámetro, de aparición aguda, con tiempo de enfermedad mayor de cinco días, atendidos en el Instituto Nacional de Salud del Niño durante el año 2012. Se definió seropositividad para B. henselae mediante el examen de inmunofluorescencia indirecta, siendo positivos 86 niños (81,1%) con una mediana de edad de 7 años, rango de 5 a 11; en el análisis bivariado se encontraron como factores asociados, edad mayor de 5 años, antecedentes de fiebre, adenopatía mayor de 4 cm y reporte de contacto con gato. En conclusión, los niños con adenitis regional atendidos en este hospital de referencia nacional presentaron una frecuencia alta de serología positiva para B. henselae.

In order to determine the frequency of seropositive cases of Bartonella henselae in children with regional adenitis treated in a national hospital in Peru, a cross-sectional study was conducted in 106 children with regional adenitis greater than 1 cm in diameter. The sample was selected from patients aged 5-11 years seen at the National Institute of Child Health for acute onset of regional adentitis, with more than five days of symptoms. B. henselae seropositivity was defined by indirect immunofluorescence test. We found that 86 children (81.1%) were positive for B.henselae. The median age of the patients was 7 years. In the bivariate analysis, the following associated factors were found: aged 5 years, history of fever, lymphadenopathy greater than 4 cm and reported contact with cat. In conclusion, children with regional adenitis treated in this national referral hospital showed a high frequency of positive serology for B. henselae.

Disulfide stress: a novel type of oxidative stress in acute pancreatitis.

Glutathione oxidation and protein glutathionylation are considered hallmarks of oxidative stress in cells because they reflect thiol redox status in proteins. Our aims were to analyze the redox status of thiols and to identify mixed disulfides and targets of redox signaling in pancreas in experimental acute pancreatitis as a model of acute inflammation associated with glutathione depletion. Glutathione depletion in pancreas in acute pancreatitis is not associated with any increase in oxidized glutathione levels or protein glutathionylation. Cystine and homocystine levels as well as protein cysteinylation and γ-glutamyl cysteinylation markedly rose in pancreas after induction of pancreatitis. Protein cysteinylation was undetectable in pancreas under basal conditions. Targets of disulfide stress were identified by Western blotting, diagonal electrophoresis, and proteomic methods. Cysteinylated albumin was detected. Redox-sensitive PP2A and tyrosine protein phosphatase activities diminished in pancreatitis and this loss was abrogated by N-acetylcysteine. According to our findings, disulfide stress may be considered a specific type of oxidative stress in acute inflammation associated with protein cysteinylation and γ-glutamylcysteinylation and oxidation of the pair cysteine/cystine, but without glutathione oxidation or changes in protein glutathionylation. Two types of targets of disulfide stress were identified: redox buffers, such as ribonuclease inhibitor or albumin, and redox-signaling thiols, which include thioredoxin 1, APE1/Ref1, Keap1, tyrosine and serine/threonine phosphatases, and protein disulfide isomerase. These targets exhibit great relevance in DNA repair, cell proliferation, apoptosis, endoplasmic reticulum stress, and inflammatory response. Disulfide stress would be a specific mechanism of redox signaling independent of glutathione redox status involved in inflammation.

Pancreatic ascites haemoglobin up-regulates the HIF/VEGF pathway in the lung in severe acute pancreatitis.

Extracellular haemoglobin (EHb) is considered a toxic molecule due to its cytotoxicity and peroxidase activity. EHb may release free hemin that increases vascular permeability, leukocyte recruitment, and adhesion molecule expression. Pancreatitis-associated ascitic fluid is reddish and may contain cell-free hemoglobin. Our aim was to determine the role of EHb in the local and systemic inflammatory response during severe acute pancreatitis in rats. To this end, taurocholate-induced necrotizing pancreatitis in rats was used. EHb levels were quantified in ascites and plasma and the hemolytic action of ascitic fluid was tested. Furthermore, we assessed if peritoneal lavage prevented the increase in EHb levels in plasma during pancreatitis. Finally, hemoglobin was purified from rat erythrocytes and administered i.p. to assess the local and systemic effects of ascitic-associated EHb during acute pancreatitis. EHb levels markedly increased in ascitic fluid and plasma during necrotizing pancreatitis. Peroxidase activity was very high in ascites. The peritoneal lavage abrogated the increase in cell-free hemoglobin in plasma. The administration of EHb enhanced ascites, dramatically increased abdominal fat necrosis, up-regulated tumor necrosis factor-a, interleukin 1ß and interleukin 6 gene expression and decreased expression of interleukin 10 in abdominal adipose tissue during pancreatitis. EHb enhanced the gene expression and protein levels of vascular endothelial growth factor (VEGF) and other hypoxia inducible factor-related genes [inducible nitric oxide synthase (inos), endothelial nitric oxide synthase (enos) and hexokinase 2] in the lung. EHb also increased myeloperoxidase activity in the lung. In conclusion, extracellular hemoglobin contributes to the inflammatory response in severe acute pancreatitis through abdominal fat necrosis and inflammation and increasing VEGF and leukocyte infiltration in the lung.

Lung myofibroblasts are characterized by down-regulated cyclooxygenase-2 and its main metabolite, prostaglandin E2.

BACKGROUND: Prostaglandin E2 (PGE2), the main metabolite of cyclooxygenase (COX), is a well-known anti-fibrotic agent. Moreover, myofibroblasts expressing α-smooth muscle actin (α-SMA), fibroblast expansion and epithelial-mesenchymal transition (EMT) are critical to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Our aim was to investigate the expression of COX-2 and PGE2 in human lung myofibroblasts and establish whether fibroblast-myofibroblast transition (FMT) and EMT are associated with COX-2 and PGE2 down-regulation. METHODS: Fibroblasts obtained from IPF patients (n = 6) and patients undergoing spontaneous pneumothorax (control, n = 6) and alveolar epithelial cell line A549 were incubated with TGF-ß1 and FMT and EMT markers were evaluated. COX-2 and α-SMA expression, PGE2 secretion and cell proliferation were measured after IL-1ß and PGE2 incubation. RESULTS: Myofibroblasts from both control and IPF fibroblast cultures stimulated with IL-1ß showed no COX-2 expression. IPF fibroblasts showed increased myofibroblast population and reduced COX-2 expression in response to IL-1ß. TGF-ß1 increased the number of myofibroblasts in a time-dependent manner. In contrast, TGF-ß1 induced slight COX-2 expression at 4 h (without increase in myofibroblasts) and 24 h, but not at 72 h. Both IPF and control cultures incubated with TGF-ß1 for 72 h showed diminished COX-2 induction, PGE2 secretion and α-SMA expression after IL-1ß addition. The latter decreased proliferation in fibroblasts but not in myofibroblasts. A549 cells incubated with TGF-ß1 for 72 h showed down-regulated COX-2 expression and low basal PGE2 secretion in response to IL-1ß. Immuno-histochemical analysis of IPF lung tissue showed no COX-2 immuno-reactivity in myofibroblast foci. CONCLUSIONS: Myofibroblasts are associated with COX-2 down-regulation and reduced PGE2 production, which could be crucial in IPF development and progression.

Telomerase and telomere length in pulmonary fibrosis.

In addition to its expression in stem cells and many cancers, telomerase activity is transiently induced in murine bleomycin (BLM)-induced pulmonary fibrosis with increased levels of telomerase transcriptase (TERT) expression, which is essential for fibrosis. To extend these observations to human chronic fibrotic lung disease, we investigated the expression of telomerase activity in lung fibroblasts from patients with interstitial lung diseases (ILDs), including idiopathic pulmonary fibrosis (IPF). The results showed that telomerase activity was induced in more than 66% of IPF lung fibroblast samples, in comparison with less than 29% from control samples, some of which were obtained from lung cancer resections. Less than 4% of the human IPF lung fibroblast samples exhibited shortened telomeres, whereas less than 6% of peripheral blood leukocyte samples from patients with IPF or hypersensitivity pneumonitis demonstrated shortened telomeres. Moreover, shortened telomeres in late-generation telomerase RNA component knockout mice did not exert a significant effect on BLM-induced pulmonary fibrosis. In contrast, TERT knockout mice exhibited deficient fibrosis that was independent of telomere length. Finally, TERT expression was up-regulated by a histone deacetylase inhibitor, while the induction of TERT in lung fibroblasts was associated with the binding of acetylated histone H3K9 to the TERT promoter region. These findings indicate that significant telomerase induction was evident in fibroblasts from fibrotic murine lungs and a majority of IPF lung samples, whereas telomere shortening was not a common finding in the human blood and lung fibroblast samples. Notably, the animal studies indicated that the pathogenesis of pulmonary fibrosis was independent of telomere length.

Low prostaglandin E2 and cyclooxygenase expression in nasal mucosa fibroblasts of aspirin-intolerant asthmatics.

BACKGROUND AND OBJECTIVE: Anomalies in the regulation of cyclooxygenase (COX)-1 and -2 have been described in nasal polyps of aspirin-induced asthma (AIA). Whether these anomalies are specific to nasal polyps or affect all the nasal mucosa (NM) of upper airways is still unclear. The objective of this study was to compare the COX pathway in NM of AIA patients with the NM of control subjects. METHODS: Fibroblasts were isolated from NM of five AIA patients (AIA-NM) and five control subjects (control-NM). Cells were treated with 10 ng/mL interleukin (IL)-1ß for up to 72 h. Prostaglandin E2 (PGE2 ) production was measured by enzyme-linked immunosorbent assay (ELISA), expression of COX-1 protein by Western blot and COX-2 protein by ELISA, Western blot and immunofluorescence techniques. RESULTS: IL-1ß increased PGE2 production and COX-1 protein expression in control-NM fibroblasts, but no changes were found in AIA-NM. IL-1ß provoked a significant time-dependent increase in COX-2 protein expression in control-NM fibroblasts but had a very mild effect on COX-2 protein expression in AIA-NM. CONCLUSIONS: Our data suggest that abnormalities in the COX pathway are not a phenomenon exclusive to nasal-polyp mucosa as they are also present in all the NM of AIA patients. These anomalies may be involved in the pathogenesis of airway inflammation and non-steroidal anti-inflammatory drug intolerance in asthma patients with chronic rhinosinusitis and nasal polyposis.

Obese rats exhibit high levels of fat necrosis and isoprostanes in taurocholate-induced acute pancreatitis.

BACKGROUND: Obesity is a prognostic factor for severity in acute pancreatitis in humans. Our aim was to assess the role of oxidative stress and abdominal fat in the increased severity of acute pancreatitis in obese rats. METHODOLOGY: Taurocholate-induced acute pancreatitis was performed in lean and obese Zucker rats. Levels of reduced glutathione, oxidized glutathione, L-cysteine, cystine, and S-adenosylmethionine were measured in pancreas as well as the activities of serine/threonine protein phosphatases PP1 and PP2A and tyrosin phosphatases. Isoprostane, malondialdehyde, triglyceride, and free fatty acid levels and lipase activity were measured in plasma and ascites. Lipase activity was measured in white adipose tissue with and without necrosis and confirmed by western blotting. FINDINGS: Under basal conditions obese rats exhibited lower reduced glutathione levels in pancreas and higher triglyceride and free fatty acid levels in plasma than lean rats. S-adenosyl methionine levels were markedly increased in pancreas of obese rats. Acute pancreatitis in obese rats led to glutathione oxidation and lower reduced glutathione levels in pancreas together with decreased activities of redox-sensitive phosphatases PP1, and PP2A. S-adenosyl methionine levels decreased but cystine levels increased markedly in pancreas upon pancreatitis. Acute pancreatitis triggered an increase in isoprostane levels in plasma and ascites in obese rats. Free fatty acid levels were extremely high in pancreatitis-associated ascitic fluid from obese rats and lipase was bound with great affinity to white adipose tissue, especially to areas of necrosis. CONCLUSIONS: Our results show that oxidative stress occurs locally and systemically in obese rats with pancreatitis favouring inactivation of protein phosphatases in pancreas, which would promote up-regulation of pro-inflammatory cytokines, and the increase of isoprostanes which might cause powerful pulmonary and renal vasoconstriction. Future studies are needed to confirm the translational relevance of the present findings obtained in a rat model of taurocholate-induced pancreatic damage and necrosis.