Identification of SULF1 as a Shared Gene in Idiopathic Pulmonary Fibrosis and Lung Adenocarcinoma / 中国肺癌杂志

BACKGROUND@#Idiopathic pulmonary fibrosis (IPF) is an idiopathic chronic, progressive interstitial lung disease with a diagnosed median survival of 3-5 years. IPF is associated with an increased risk of lung cancer. Therefore, exploring the shared pathogenic genes and molecular pathways between IPF and lung adenocarcinoma (LUAD) holds significant importance for the development of novel therapeutic approaches and personalized precision treatment strategies for IPF combined with lung cancer.@*METHODS@#Bioinformatics analysis was conducted using publicly available gene expression datasets of IPF and LUAD from the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis was employed to identify common genes involved in the progression of both diseases, followed by functional enrichment analysis. Subsequently, additional datasets were used to pinpoint the core shared genes between the two diseases. The relationship between core shared genes and prognosis, as well as their expression patterns, clinical relevance, genetic characteristics, and immune-related functions in LUAD, were analyzed using The Cancer Genome Atlas (TCGA) database and single-cell RNA sequencing datasets. Finally, potential therapeutic drugs related to the identified genes were screened through drug databases.@*RESULTS@#A total of 529 shared genes between IPF and LUAD were identified. Among them, SULF1 emerged as a core shared gene associated with poor prognosis. It exhibited significantly elevated expression levels in LUAD tissues, concomitant with high mutation rates, genomic heterogeneity, and an immunosuppressive microenvironment. Subsequent single-cell RNA-seq analysis revealed that the high expression of SULF1 primarily originated from tumor-associated fibroblasts. This study further demonstrated an association between SULF1 expression and tumor drug sensitivity, and it identified potential small-molecule drugs targeting SULF1 highly expressed fibroblasts.@*CONCLUSIONS@#This study identified a set of shared molecular pathways and core genes between IPF and LUAD. Notably, SULF1 may serve as a potential immune-related biomarker and therapeutic target for both diseases.

Role of various imbalances centered on alveolar epithelial cell/fibroblast apoptosis imbalance in the pathogenesis of idiopathic pulmonary fibrosis / 中华医学杂志(英文版)

There have been recent extensive studies and rapid advancement on the pathogenesis underlying idiopathic pulmonary fibrosis (IPF), and intricate pathogenesis of IPF has been suggested. The purpose of this study was to clarify the logical relationship between these mechanisms. An extensive search was undertaken of the PubMed using the following keywords: "etiology," "pathogenesis," "alveolar epithelial cell (AEC)," "fibroblast," "lymphocyte," "macrophage," "epigenomics," "histone," acetylation," "methylation," "endoplasmic reticulum stress," "mitochondrial dysfunction," "telomerase," "proteases," "plasminogen," "epithelial-mesenchymal transition," "oxidative stress," "inflammation," "apoptosis," and "idiopathic pulmonary fibrosis." This search covered relevant research articles published up to April 30, 2020. Original articles, reviews, and other articles were searched and reviewed for content; 240 highly relevant studies were obtained after screening. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors: environmental exposures affect epigenetic marks; epigenetic processes translate environmental exposures into the regulation of chromatin; epigenetic processes shape gene expression profiles; in turn, an individual's genetic background determines epigenetic marks; finally, these genetic and epigenetic factors act in concert to dysregulate gene expression in IPF lung tissue. The pathogenesis of IPF involves various imbalances including endoplasmic reticulum, telomere length homeostasis, mitochondrial dysfunction, oxidant/antioxidant imbalance, Th1/Th2 imbalance, M1-M2 polarization of macrophages, protease/antiprotease imbalance, and plasminogen activation/inhibition imbalance. These affect each other, promote each other, and ultimately promote AEC/fibroblast apoptosis imbalance directly or indirectly. Excessive AEC apoptosis and impaired apoptosis of fibroblasts contribute to fibrosis. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors. The pathogenesis of IPF involves various imbalances centered on AEC/fibroblast apoptosis imbalance.

¿El reflujo gastroesofágico y la aspiración de contenido gástrico están implicados en la etiopatogenia y la progresión de la fibrosis pulmonar idiopática? / Does gastroesophageal reflux and gastric content aspiration have some role in the pathogenesis and progression of Idiopathic Pulmonary Fibrosis?

Resumen El reflujo gastroesofágico (RGE) y la aspiración oculta de contenido digestivo están probablemente implicados en la etiopatogenia y progresión de la fibrosis pulmonar idiopática (FPI). Los mecanismos patogénicos involucrados son la disminución de la distensibilidad pulmonar y el consiguiente aumento de la presión negativa intratorácica durante la inspiración, así como la disminución de los mecanismos de control de la motilidad esofágica o del tono del esfínter esofágico inferior. La prevalencia de RGE y anomalías de la motilidad esofágica están aumentadas en los pacientes con FPI comparado con la población general. Entre los pacientes con FPI, el 67-76% demostraron exposición anormal al contenido ácido en el esófago. Sin embargo, no hubo relación entre la gravedad del RGE y la gravedad de la FPI. Los estudios que han examinado el tratamiento antirreflujo en esta población han sido escasos. Incluso, algunos datos sugieren que el tratamiento antiácido puede ser perjudicial en algunos pacientes con esta condición. Después de analizar toda la evidencia relevante encontrada hasta la fecha, concluimos que no se puede establecer una relación causal entre el RGE, la aspiración del contenido gástrico y la patogénesis de la FPI. Además, existe escasa evidencia clínica que haya examinado el tratamiento antirreflujo en pacientes con fibrosis pulmonar idiopática.

ABSTRACT Gastroesophageal reflux (GERD) and hidden aspiration of gastric contents are probably involved in the pathogenesis and progression of idiopathic pulmonary fibrosis (IPF). The pathological mechanisms involved are decreased pulmonary distensibility and consequent increase of intrathoracic negative pressure during inspiration, as well as decreased control mechanisms of esophageal motility or lower esophageal sphincter. The prevalence of GERD and oesophageal dysmotility was higher in patients with IPF as compared with general population. Among patients with IPF, 67-76% demonstrated abnormal oesophageal acid exposure. However, no relationship was demonstrated between severity of GERD and severity of IPF. Data are scant on outcomes of antireflux treatment in patients with IPF. Actually, some data suggests that antacid treatment may be deleterious in some IPF patients. After analyzing all the relevant evidence found to date, a causal relationship between GERD, gastric content aspiration and IPF pathogenesis cannot be established. There is scant evidence examining antireflux treatment in idiopathic pulmonary fibrosis patients.

Fibrosis pulmonar idiopática / Idiopathic pulmonary fibrosis

La FPI predomina en el sexo masculino, en edades avanzadas, con tos y/o disnea progresivas. Un 5% se presenta como una forma familiar. La tomografía axial computarizada de tórax, fundamental en el diagnóstico, en al menos un 50% hace innecesaria la biopsia. El diagnóstico es conjunto con clínicos, radiólogos y patólogos. La sobrevivencia media es de tres a cinco años desde el diagnóstico. La historia natural es un deterioro progresivo, pero hay formas rápidas y también pueden aparecer exacerbaciones que ensombrecen el pronóstico. Diversas comorbilidades se han descrito como la hipertensión pulmonar, la asociación con enfisema y el reflujo gastroesofágico. Sólo recientemente aparecen fármacos útiles, que son la Pirfenidona y el Nintedanib. El clásico esquema de prednisona, azatriopina y N-acetil cisteina, se ha demostrado ineficaz. Otros recursos que pueden utilizarse como complementos útiles en la enfermedad son el oxígeno, la rehabilitación, las terapias antirreflujo y el manejo sintomático de la tos.

PF appears mainly in aged males, with progressive cough and dyspnea. In 5% of the cases the disease presents as a familial form. CT scan is key in diagnosis of the disease. In no less than 50% biopsy is unnecessary but diagnosis must be made in conjunction with clinician, radiologist and pathologist. Median survival is 3 to 5 years from diagnosis. Natural history is a progressive deterioration but there are fast evolution cases and exacerbation of the disease that make worse the prognosis. Pulmonary hypertension, the association with emphysema and gastroesophageal reflux has been described as comorbidities of the disease. Last year has been published the positive results of therapeuticall trials with two new drugs, Pirfenidone and Nintedanib. The classical regime for IPF with Prednisone, Azathriopine and Acetylcysteine has been showed as useless. Oxygen, Pulmonary rehabilitation, gastroesophageal reflux and cough management are complementary treatment for the disease.