Exosomal Micro-RNAs as Intercellular Communicators in Idiopathic Pulmonary Fibrosis.

Communication between neighboring or distant cells is made through a complex network that includes extracellular vesicles (EVs). Exosomes, which are a subgroup of EVs, are released from most cell types and have been found in biological fluids such as urine, plasma, and airway secretions like bronchoalveolar lavage (BAL), nasal lavage, saliva, and sputum. Mainly, the cargo exosomes are enriched with mRNAs and microRNAs (miRNAs), which can be transferred to a recipient cell consequently modifying and redirecting its biological function. The effects of miRNAs derive from their role as gene expression regulators by repressing or degrading their target mRNAs. Nowadays, various types of research are focused on evaluating the potential of exosomal miRNAs as biomarkers for the prognosis and diagnosis of different pathologies. Nevertheless, there are few reports on their role in the pathophysiology of idiopathic pulmonary fibrosis (IPF), a chronic lung disease characterized by progressive lung scarring with no cure. In this review, we focus on the role and effect of exosomal miRNAs as intercellular communicators in the onset and progression of IPF, as well as discussing their potential utility as therapeutic agents for the treatment of this disease.

Role of MicroRNAs in Signaling Pathways Associated with the Pathogenesis of Idiopathic Pulmonary Fibrosis: A Focus on Epithelial-Mesenchymal Transition.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease with high mortality and unclear etiology. Previous evidence supports that the origin of this disease is associated with epigenetic alterations, age, and environmental factors. IPF initiates with chronic epithelial lung injuries, followed by basal membrane destruction, which promotes the activation of myofibroblasts and excessive synthesis of extracellular matrix (ECM) proteins, as well as epithelial-mesenchymal transition (EMT). Due to miRNAs' role as regulators of apoptosis, proliferation, differentiation, and cell-cell interaction processes, some studies have involved miRNAs in the biogenesis and progression of IPF. In this context, the analysis and discussion of the probable association of miRNAs with the signaling pathways involved in the development of IPF would improve our knowledge of the associated molecular mechanisms, thereby facilitating its evaluation as a therapeutic target for this severe lung disease. In this work, the most recent publications evaluating the role of miRNAs as regulators or activators of signal pathways associated with the pathogenesis of IPF were analyzed. The search in Pubmed was made using the following terms: "miRNAs and idiopathic pulmonary fibrosis (IPF)"; "miRNAs and IPF and signaling pathways (SP)"; and "miRNAs and IPF and SP and IPF pathogenesis". Additionally, we focus mainly on those works where the signaling pathways involved with EMT, fibroblast differentiation, and synthesis of ECM components were assessed. Finally, the importance and significance of miRNAs as potential therapeutic or diagnostic tools for the treatment of IPF are discussed.

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.

Deregulated MicroRNAs in Cancer-Associated Fibroblasts from Front Tumor Tissues of Lung Adenocarcinoma as Potential Predictors of Tumor Promotion.

Cancer-associated fibroblasts (CAFs) are the main component of the tumor stroma and promote tumor progression through several mechanisms. Recent evidence indicates that small noncoding RNAs, microRNAs (miRNAs), play key roles in CAF tumor-promoting properties; however, the role of miRNAs in lung cancer-associated fibroblasts remains poorly defined. We characterized the differential miRNA expression profile of fibroblasts isolated from matched tumor front (F-CAFs), inner tumor (In-CAFs), and normal adjacent (NFs) tissues from four lung adenocarcinoma patients (ADs) using microarray analysis. Proliferation and invasion assays of A549 human lung cancer cells in the presence of conditioned medium from F-CAFs, In-CAFs or NFs were performed to assess tumorigenic properties. Ten identified candidate miRNAs in F-CAFs, In-CAFs and NFs from 12 ADs were then validated by RT-PCR. Both F-CAFs and In-CAFs enhanced the proliferation and invasion of A549 cells compared with NFs; moreover, F-CAFs showed a significantly stronger effect than In-CAFs. RT-PCR validation demonstrated three downregulated miRNAs in F-CAFs compared with NFs (miR-145-3p, miR-299-3p, and miR-505-3p), two in F-CAFs compared with In-CAFs (miR-410-3p and miR-485-5p), but no differentially expressed miRNAs between In-CAFs and NFs. Further target-gene prediction and pathway enrichment analysis indicated that deregulated miRNAs in F-CAFs showed significant associations with "pathways in cancer" (miR-145-3p, miR-299-3p and miR-410-3p), "Wnt signaling pathway" (miR-410-3p and miR-505-3p), and "TGF-beta signaling pathway" (miR-410-3p). Importantly, a tumor-promoting growth factor targeted by those miRNAs, VEGFA, was upregulated in F-CAFs compared with NFs, as judged by RT-PCR. In conclusion, deregulated miRNAs in F-CAFs are potentially associated with CAF tumor-promoting properties.

Association between IL-15 and insulin plasmatic concentrations in patients with pulmonary tuberculosis and type 2 diabetes.

IL-15 is part of the immune response in pulmonary tuberculosis (PTB) but amazingly, it may also induce physiological effects similar to those of insulin. We evaluated the IL-15 and insulin plasmatic levels in adults with PTB and with or without type 2 diabetes mellitus (DM2), who received previous antituberculosis therapy for at least 2 months. We analyzed the concentrations of glucose, glycated hemoglobin, insulin, as well as levels of IL-15, IL-2, IFN-γ, and TNF-α in patients with PTB, patients with PTB-DM2, household contacts with DM2 (C-DM2), and healthy household contacts (H-C). Our results showed unexpected high levels of glucose, insulin, and IL-15 in the PTB and C-DM2 groups. In comparison, low levels of these same indicators were observed in the PTB-DM2 and H-C groups. Interestingly, our analysis showed a positive correlation of IL-15 with insulin in the PTB group (r = 0.73) and in the C-DM2 group (r = 0.66). In comparison, a weak correlation between IL-15 and insulin was observed in the PTB-DM group (r = 0.10) and in the H-C group (ρ = 0.26). Our results suggest an association between IL-15 and insulin levels in the patient with PTB. Intriguingly, this association was weaker in the patient with PTB-DM2.

Secreted and Tissue miRNAs as Diagnosis Biomarkers of Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor that originates in the pleura, is diagnosed in advanced stages and has a poor prognosis. Accurate diagnosis of MPM is often difficult and complex, and the gold standard diagnosis test is based on qualitative analysis of markers in pleural tissue by immunohistochemical staining. Therefore, it is necessary to develop quantitative and non-subjective alternative diagnostic tools. MicroRNAs are non-coding RNAs that regulate essential cellular mechanisms at the post-transcriptional level. Recent evidence indicates that miRNA expression in tissue and body fluids is aberrant in various tumors, revealing miRNAs as promising diagnostic biomarkers. This review summarizes evidence regarding secreted and tissue miRNAs as biomarkers of MPM and the biological characteristics associated with their potential diagnostic value. In addition to studies regarding miRNAs with potential diagnostic value for MPM, studies that aimed to identify the miRNAs involved in molecular mechanisms associated with MPM development are described with an emphasis on relevant aspects of the experimental designs that may influence the accuracy, consistency and real diagnostic value of currently reported data.

Analysis of microRNA expression signatures in malignant pleural mesothelioma, pleural inflammation, and atypical mesothelial hyperplasia reveals common predictive tumorigenesis-related targets.

Pleural chronic inflammation (PP) and mesothelial hyperplasia (HP) may be critical to the development of malignant pleural mesothelioma (MPM). Nonetheless, studies searching for mechanistic links involving microRNA (miRNA) regulation among these interrelated processes have not been reported. Using PCR-Array, we identified the miRNAs expressed in pleural tissues diagnosed with MPM (n=5), PP (n=4) and HP (n=5), as well as in non-cancerous/non-inflammatory tissue as the normal control (n=5). We performed bioinformatics and network analysis of differentially expressed miRNAs to identify tumorigenesis-related miRNAs and their biological networks. The targets of four down-regulated miRNAs in MPM (mir-181a-5p, miR-101-3p, miR-145-5p and miR-212-3p), one in PP (mir-101-3p) and one in HP (mir-494) were significantly enriched in "pathways in cancer". Interactome networks revealed that >50% of down-regulated miRNAs in MPM targeted the signaling-activation molecule MAPK1, the transcription factor ETS1 and the mesenchymal transition-associated molecule FZDA, which have been associated with oncogenic function. Comparative analysis revealed that FZD4 was an overlapping gene target of down-regulated miRNAs that were associated with "pathways in cancer" in MPM, PP and HP. Moreover, MAPK1, ETS1 and Cox-2, a pro-inflammatory enzyme associated with over-expression in cancers, were among the 25 overlapping target genes in MPM and PP. This network analysis revealed a potential combinatory effect of deregulated miRNAs in MPM pathogenesis and indicated potential molecular links between pleural inflammation and hyperplasia with tumorigenesis mechanisms in pleura.

The IL1B-511 Polymorphism (rs16944 AA Genotype) Is Increased in Aspirin-Exacerbated Respiratory Disease in Mexican Population.

Aspirin exacerbated respiratory disease (AERD) is characterized by chronic hyperplastic rhinosinusitis, nasal polyposis, asthma, and aspirin sensitivity. The mechanisms which produce these manifestations of intolerance are not fully defined, current research focuses on cyclooxygenase 1 (COX-1) inhibition, metabolism of arachidonic acid, and the COX pathway to the lipoxygenase (LO) route, inducing increased synthesis of leukotrienes (LT). The biological plausibility of this model has led to the search for polymorphisms in genes responsible for proinflammatory cytokines synthesis, such as IL1B and IL8. We performed a genetic association study between IL8-251 (rs4073) and IL1B-511 (rs16944) polymorphisms in AERD, aspirin-tolerant asthma (ATA), and healthy control subjects. Using allelic discrimination by real-time PCR, we found statistically nonsignificant associations between AERD, ATA, and healthy control subjects for the GG and GA genotypes of IL1B (rs16944). Interestingly, the AA genotype showed an increased frequency in the AERD patients versus the ATA group (GF = 0.19 versus 0.07, p = 0.018, OR 2.98, and 95% CI 1.17-7.82). This is the first observation that IL1B polymorphisms are involved in AERD. Thus, future studies must investigate whether interleukin-1ß is released in the airways of AERD patients and whether it relates to genetic polymorphisms in the IL1B gene.

Human ß-defensin-2 induction in nasal mucosa after administration of bacterial lysates.

BACKGROUND AND AIMS: The airway epithelium produces antimicrobial peptides (AMPs) that prevent colonization of host tissues by a wide range of pathogens. Human ß-defensin 2 (hBD-2) is one of the most well-documented AMPs in humans. Several bacterial products can induce production of this peptide. Bacterial immunostimulants containing bacterial lysates have long been used in the treatment of respiratory infections, but their effects on hBD-2 release have not been investigated. We undertook this study to induce production of hBD-2 after stimulation of the nasal mucosa with bacterial lysates. METHODS: A nasal lavage (NL) was performed in 12 healthy volunteers under basal conditions and after a nasal challenge with separate and subsequent stimuli with either bacterial lysates (20 million), cholecalciferol (400 IU), or sham-challenge with glycerol plus isotonic saline solution. Immunohistochemistry was performed in nasal biopsies 48 h after stimulation with bacterial lysates to identify the presence of hBD-2. RESULTS: Increased levels of hBD-2 (4668.99 ± 2829.33 pg/mL) were measured with ELISA in NL fluids following bacterial challenge. However, hBD-2 concentrations were below the limit of detection in NL fluids at baseline and after the administration of cholecalciferol or the sham-challenge. Through immunohistochemistry, hBD-2 was predominantly localized to the epithelium. CONCLUSIONS: hBD-2 can be induced in the nasal mucosa after administration of bacterial lysates. Stimulation of the innate immune system to produce hBD-2 could be used to prevent or even treat infections caused by respiratory pathogens.

Chemokine (C-X-C motif) ligand 12/stromal cell-derived factor-1 is associated with leukocyte recruitment in asthma.

BACKGROUND: Asthma is characterized by allergic airway inflammatory response involving extensive leukocyte infiltration. The stromal cell-derived factor (SDF)-1 or chemokine (C-X-C motif) ligand 12 (CXCL12) attracts a number of cells, including resting T lymphocytes, monocytes, CD34(+) stem cells, basophils, and mature eosinophils. To date, however, the potential role of CXCL12/SDF-1 in relation to leukocyte recruitment in asthma has not been previously examined, to our knowledge. METHODS: Levels of CXCL12/SDF-1 in the BAL fluid (BALF) of 15 subjects with asthma and 13 healthy subjects were measured by enzyme-linked immunosorbent assay. Immunohistochemistry was performed to identify the cellular source of this chemokine. RESULTS: CXCL12/SDF-1 concentrations were significantly elevated in BALF from subjects with asthma compared with normal subjects (median 845 pg/mL, range, 296-1,700 pg/mL vs median 55 pg/mL, range 25-97 pg/mL; P < .001). Concentrations of CXCL12/SDF-1 correlated with macrophages (r = 0.728, P < .01), lymphocytes (r = 0.651, P < .01), and eosinophils (r = 0.765, P < .01). By immunohistochemistry, CXCL12/SDF-1 was localized to the airway epithelium and to a lesser extent to mononuclear cells. CONCLUSION: CXCL12/SDF-1 is released in high concentration in BALF of patients with asthma. The finding that concentrations of this chemokine correlated with leukocyte numbers in BALF suggests that this chemokine may contribute to the cell recruitment in asthma.

Dermatomiositis del niño: estudio inmunológico / Childhool dermatomyositis: immunologic study

Estudiamos 8 niños con dermatomiositis con el objeto de detectar las anormalidades inmunológicas relacionadas al padecimiento. Las inmunoglobulinas séridas IgG, IgM e IgA, fueron determinadas por nefelometría, resultando normales en todos los casos, excepto en 2 enfermos, en quienes se notó un ligero incremento sin relación con la fase de actividad de la enfermedad. Sólo un paciente tuvo descenso de C4 asocaido a miopatía activa, pero no con vasculitis. No detectamos hipogamaglobulinemia y la prueba de VDRL fue negativa en todos los niños. El factor reumatoide fue positivo en 4 casos con títulos menores de 1:80 por la técnica de Waaler Rose. Los anticuerpos antinucleares por inmunofluorescencia indirecta estuvieron presentes en 5 niños, predominando el patrón moteado, resultados que no tuvieron relación con la exacerbación del padecimiento. No hubo anticuerpos anti-DNAn, o contra antígenos nucleares extraibles. Los anticuerpos anti-Jo-1, Mi-1 y Mi-2 fueron negativos. Los anticuerpos anti-toxoplasma de la clase IgG por la prueba de inmunofluorescencia indirecta estuvieron presentes en 7 pacientes. En ningún caso de encontró historia de toxoplasmosis ni datos de este padecimiento al momento del estudio o durante el seguimiento. Los anticuerpos anti-músculo liso fueron positivos en un caso. Ninguna de estas anormalidades mostró correlación con la actividad del padecimiento.

Lupus eritematoso generalizado en niños con daño renal y hematológico: relación con anticuerpos anti-DNAn / Systemic lupus erythematosus in children with renal and hematologic damage: relation to anti-nDNA antibodies

Se estudiaron prospectivamente 22 niños con lupus eritematoso generalizado. A todos se les determinaron inmunoglobulinas, C3 y C4, así como anticuerpos antinucleares por inmunofluorescencia indirecta, anti-DNAn, anti-RNP y anti-SSB (La). De los 22 pacientes, 16 fueron niñas y seis niños. El promedio de edad al inicio del padecimiento fue de 12.4 años (extremos de ocho a 15 años). Cuatro pacientes presentaron la enfermedad antes de cumplir los 10 años. Se observaron principalmente dos subgrupos clínicos, que incluyeron aquellos con daño renal, que fueron 11 pacientes (50%) y un segundo grupo de ocho pacientes (35%) con manifestaciones hematológicas, cuatro con anemia hemolítica y cuatro con púrpura trombocitopenica. Observamos que siete de los 11 pacientes con daño renal, tuvieron glomerulonefritis proliferativa difusa, uno lesión focal y otro glomerulonefritis mesangial. No se realizó biopsia en dos casos. En el grupo con alteraciones hematológicas, solo una paciente con anemia hemolitica presentó nefropatía al segimiento. Tres de los 22 pacientes desarrollaron procesos linfoproliferativos en coexistencia con el lupus eritematoso generalizado. Al estudiar las características serológicas y relacionarlas en ambos grupos de lupus eritematoso generalizado, mediante las pruebas de X2 y tabla de cintingencia triple, encontramos que los anticuerpos anti-DNA y disminución de C3, se asociaron significativamente con daño renal, pero no con las manifestaciones hematológicas, a pesar de que el 50% de los pacientes con estas últimas anormalidades presentaron anticuerpos anti-DNAn y C3 bajo. Queda por definir si diferencias inmunoquímicas entre los anticuerpoos anti-DNAn en estos grupo de pacientes con lupus eritematoso generalizado, pueden establecer una división en el comportamiento clínico con o sin nefropatía. Lupus eritematoso generalizado; nefropatía; manifestaciones hematológicas; anticuerpos anti-DNAn