Exosomal circRNAs in the plasma serve as novel biomarkers for IPF diagnosis and progression prediction.

BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) is a type of chronic interstitial pneumonia, often fatal, with elusive causes and a bleak prognosis. Its treatment options are limited and largely ineffective. Early detection and precise diagnosis are pivotal in managing the disease effectively and enhancing patient survival rates. Recently, the quest for trustworthy biomarkers for IPF has gained momentum. Notably, emerging studies indicate that circular RNAs (circRNAs) found in exosomes may hold significant potential as valuable diagnostic markers. METHODS: In this study, we initially explored the expression profile of circRNAs in exosomes sourced from the blood of IPF patients and healthy volunteers, employing a human circRNA microarray. We then utilized RT-qPCR to corroborate the dysregulated circRNAs identified by the microarray during the training phase. Next, the circRNAs that displayed a significant increase during the training phase were selected for further validation in a larger cohort encompassing 113 IPF patients and 76 healthy volunteers. Ultimately, the expression level and function of hsa_circ_0044226 were substantiated through a series of in vivo and in vitro experiments. RESULTS: Utilizing a human circRNA microarray, we identified 11 dysregulated circRNAs in the exosomes derived from the blood of IPF patients and control volunteers. Subsequent RT-qPCR analysis revealed significant increases in three circRNAs (hsa_circ_0044226, hsa_circ_0004099, hsa_circ_0008898) within the IPF patients. Notably, hsa_circ_0044226 was markedly elevated in patients experiencing acute exacerbation of IPF (AE-IPF) compared to those with stable IPF (S-IPF). Additionally, an upregulation of hsa_circ_0044226 was observed in the blood exosomes derived from a bleomycin-induced IPF mouse model. CONCLUSION: The expression levels of hsa_circ_0044226, hsa_circ_0004099, and hsa_circ_0008898 in plasma exosomes introduce a new paradigm of biomarkers for the diagnosis and progression of IPF.

Transcriptomics-proteomics Integration reveals alternative polyadenylation driving inflammation-related protein translation in patients with diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is a complex disease involving the upregulation of many inflammation-related proteins. Alternative polyadenylation (APA), a crucial post-transcriptional regulatory mechanism, has been proven to play vital roles in many inflammatory diseases. However, it is largely unknown whether and how APA exerts function in DN. METHODS: We performed transcriptomics and proteomics analysis of glomeruli samples isolated from 50 biopsy-proven DN patients and 25 control subjects. DaPars and QAPA algorithms were adopted to identify APA events from RNA-seq data. The qRT-PCR analysis was conducted to verify 3'UTR length alteration. Short and long 3'UTRs isoforms were also overexpressed in podocytes under hyperglycemia condition for examining protein expression. RESULTS: We detected transcriptome-wide 3'UTR APA events in DN, and found that APA-mediated 3'UTR lengthening of genes (APA genes) increased their expression at protein but not mRNA level. Increased protein level of 3'UTR lengthening gene was validated in podocytes under hyperglycemia condition. Pathway enrichment analysis showed that APA genes were enriched in inflammation-related biological processes including endoplasmic reticulum stress pathways, NF-κB signaling and autophagy. Further bioinformatics analysis demonstrated that 3'UTR APA of genes probably altered the binding sites for RNA-binding proteins, thus enhancing protein translation. CONCLUSION: This study revealed for the first time that 3'UTR lengthening of APA genes contributed to the progression of DN by elevating the translation of corresponding proteins, providing new insight and a rich resource for investigating DN mechanisms.

Pinocembrin relieves lipopolysaccharide and bleomycin induced lung inflammation via inhibiting TLR4-NF-κB-NLRP3 inflammasome signaling pathway.

Inflammation is a defense response of the body to stimuli. Lung injury caused by external stimuli can stimulate inflammatory cells to accumulate at the site of injury and secrete cytokines. Pinocembrin is a flavonoid with anti-inflammatory effects. Based on previous studies, we further explored the anti-inflammatory mechanisms of pinocembrin in vitro and in vivo. In vitro studies indicated that pinocembrin inhibited lipopolysaccharide (LPS)-stimulated inflammatory response in macrophages. In vivo studies also showed that pinocembrin could reduce LPS and bleomycin (BLM) induced lung inflammatory response in mice. Further mechanistic studies indicated that pinocembrin could regulate the TLR4-NF-κB signaling pathway and suppressed the activation and assembly of NLRP3 inflammasomes. In summary, pinocembrin could relieve pulmonary inflammatory response induced by LPS and BLM mainly via inhibiting TLR4-NF-κB-NLRP3 inflammasome axis. These results contribute to the understanding of the anti-inflammatory mechanisms of pinocembrin and serve as reference for future research on pinocembrin.

Anlotinib attenuated bleomycin-induced pulmonary fibrosis via the TGF-ß1 signalling pathway.

OBJECTIVES: Anlotinib hydrochloride (AL3818) is a novel multitarget tyrosine kinase inhibitor which has the same targets as nintedanib, an effective drug has been approved for the treatment of idiopathic pulmonary fibrosis. Here, we examined whether anlotinib could also attenuate bleomycin-induced pulmonary fibrosis in mice and explored the antifibrosis mechanism. METHODS: We have evaluated the effect of anlotinib on bleomycin-induced pulmonary fibrosis in mice. Inflammatory cytokines in alveolar lavage fluid including IL-1ß, IL-4, IL-6 and TNF-α were determined by ELISA. Biomarkers of oxidative stress were measured by corresponding kit. Histopathologic examination was analysed by H&E staining and immunohistochemistry. In vitro, we investigated whether anlotinib inhibited TGFß/Smad3 and non-Smad pathways by luciferase assay or Western blotting. We also evaluated whether anlotinib inhibited TGF-ß1-induced epithelial-mesenchymal transition (EMT) and promoted myofibroblast apoptosis in order to explore the possible molecular mechanism. KEY FINDINGS: The results indicated that anlotinib treatment remarkably attenuated inflammation, oxidative stress and pulmonary fibrosis in mouse lungs. Anlotinib could inhibit the TGF-ß1 signalling pathway. Additionally, anlotinib not only profoundly inhibited TGF-ß1-induced EMT in alveolar epithelial cells, but also simultaneously reduced the proliferation and promoted the apoptosis in fibroblasts. CONCLUSIONS: In summary, the results suggest that anlotinib-mediated suppression of pulmonary fibrosis is related to the inhibition of TGF-ß1 signalling pathway.