circFTO from M2 macrophage-derived small extracellular vesicles (sEV) enhances NSCLC malignancy by regulation miR-148a-3pPDK4 axis.

BACKGROUND: Accumulation studies found that tumor-associated macrophages (TAMs) are a predominant cell in tumor microenvironment (TME), which function essentially during tumor progression. By releasing bioactive molecules, including circRNA, small extracellular vesicles (sEV) modulate immune cell functions in the TME, thereby affecting non-small cell lung cancer (NSCLC) progression. Nevertheless, biology functions and molecular mechanisms of M2 macrophage-derived sEV circRNAs in NSCLC are unclear. METHODS: Cellular experiments were conducted to verify the M2 macrophage-derived sEV (M2-EV) roles in NSCLC. Differential circRNA expression in M0 and M2-EV was validated by RNA sequencing. circFTO expression in NSCLC patients and cells was investigated via real-time PCR and FISH. The biological mechanism of circFTO in NSCLC was validated by experiments. Our team isolated sEV from M2 macrophages (M2Ms) and found that M2-EV treatment promoted NSCLC CP, migration, and glycolysis. RESULTS: High-throughput sequencing found that circFTO was highly enriched in M2-EV. FISH and RT-qPCR confirmed that circFTO expression incremented in NSCLC tissues and cell lines. Clinical studies confirmed that high circFTO expression correlated negatively with NSCLC patient survival. Luciferase reporter analysis confirmed that miR-148a-3p and PDK4 were downstream targets of circFTO. circFTO knockdown inhibited NSCLC cell growth and metastasis in in vivo experiments. Downregulating miR-148a-3p or overexpressing PDK4 restored the malignancy of NSCLC, including proliferation, migration, and aerobic glycolysis after circFTO silencing. CONCLUSION: The study found that circFTO from M2-EV promoted NSCLC cell progression and glycolysis through miR-148a-3p/PDK4 axis. circFTO is a promising prognostic and diagnostic NSCLC biomarker and has the potential to be a candidate NSCLC therapy target.

Expression of serum circFTO and miR-141-3p in patients with diabetes retinopathy and their relationship with pathological stage / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the relationship between the changes of serum circFTO and microRNA-141-3p(miR-141-3p)levels and the different disease stages of diabetes retinopathy.METHODS: A total of 198 patients with type 2 diabetes admitted to our hospital from October 2019 to November 2022 were collected as the study subjects, the patients were grouped into non diabetes retinopathy(NDR)group(70 cases), non proliferative diabetes retinopathy(NPDR)group(66 cases)and proliferative diabetes retinopathy(PDR)group(62 cases)according to different stages; meantime, 67 volunteers with normal physical examination results were collected as the control group. The levels of serum circFTO and miR-141-3p were detected by real-time fluorescent quantitative PCR(qRT-PCR); Pearson correlation analysis was used to examine the correlation between the serum circFTO, miR-141-3p and various indicators in patients with diabetes retinopathy; multivariate Logistic regression analysis was applied to explore the influencing factors of diabetes retinopathy.RESULTS: CircFTO, systolic blood pressure(SBP), and diastolic blood pressure(DBP)in PDR group were higher than those in control group, NDR group and NPDR group, while miR-141-3p and high-density lipoprotein cholesterol(HDL-C)were lower than those in control group, NDR group and NPDR group(P<0.05). Fasting blood glucose(FPG)and glycosylated hemoglobin(HbA1c)in NDR group, NPDR group and PDR group were higher than those in the control group(all P<0.05). The course of disease in PDR group was longer than that in NDR group and NPDR group(P<0.05). Serum circFTO in patients with diabetes retinopathy was positively correlated with SBP, DBP, FPG, HbA1c, and miR-141-3p was negatively correlated with SBP, DBP, FPG, HbA1c(all P<0.05). CircFTO was a risk factor for diabetes retinopathy, and miR-141-3p was a protective factor for diabetes retinopathy(P<0.05).CONCLUSION: Serum circFTO is obviously increased and miR-141-3p is obviously decreased in patients with diabetes retinopathy, both of them are closely related to disease stage, and are expected to become important indicators for evaluating disease progress.

circFTO upregulates transforming growth factor-alpha through sponging miR-148a-3p to regulate high glucose-induced ARPE-19 cells injury.

Diabetic retinopathy (DR) is one of the most common retinal microvascular diseases in diabetic patients. Therefore, elucidating the underlying molecular mechanism of DR is of great significance for its clinical treatment. This study explores the effects of the upregulated circFTO in DR patients in terms of cell apoptosis and viability. Several molecular assays are employed to explore these molecular mechanistic aspects, such as luciferase reporter, RNA pull-down, RT-qPCR, Western blot, and ELISA assays. miR-148a-3p is downregulated in DR patients. The expression of circFTO promoted ARPE-19 cells apoptosis and inhibited proliferation, reflecting the regulatory effect of circFTO/miR-148a-3p on retinal epithelial cells injury. In addition, the absence of circFTO could reduce ARPE-19 cells injury caused by HG by inhibiting oxidative stress and inflammation. Further, the investigations at the molecular level showed that circFTO could regulate the level of miR-148a-3p and TGFA in vitro. As the molecular sponge of miR-148a-3p, circFTO regulated cell viability and apoptosis and promoted the progression of DR through regulating the expression of TGFA. Together, this study provides new targets and markers for early diagnosis and therapy of DR.

Circular Ribonucleic Acid circFTO Promotes Angiogenesis and Impairs Blood-Retinal Barrier Via Targeting the miR-128-3p/Thioredoxin Interacting Protein Axis in Diabetic Retinopathy.

Background: Increasing attention has been attracted by the role of circular RNAs (circRNAs) in ocular diseases. Previous study has revealed that circ_0005941 (also known as circFTO, an alpha-ketoglutarate-dependent dioxygenase) was upregulated in the vitreous humor of diabetic retinopathy (DR), while its underlying mechanism in DR remains unknown. Methods: Retinal vascular endothelial cells (RVECs) treated with high glucose (HG) were used to establish the DR cell model. The in vivo assays were conducted using streptozotocin-induced diabetic mice. The circular structure and stability of circFTO were identified by Sanger sequencing and RNase R treatment. RT-qPCR analysis was used to detect the RNA expression. The levels of the mRNA-encoded protein thioredoxin-interacting protein (TXNIP) or angiogenesis-associated proteins (VEGFA, PDGF, and ANG2) and blood-retinal barrier (BRB)-related proteins (ZO-1, Occludin, and Claudin-5) were measured by Western blot. The viability of RVECs was measured using CCK-8 assays. The angiogenesis of RVECs was assessed using tube formation assays in vitro. Endothelial permeability assays were conducted to examine the function of the BRB. The binding between genes was explored using RNA pulldown and luciferase reporter assays. Results: CircFTO was upregulated in HG-treated RVECs. CircFTO deficiency reversed the HG-induced increase in the viability and angiogenesis of RVECs and alleviated HG-mediated impairment of the BRB. MiR-128-3p bound with circFTO and was downregulated in HG-treated RVECs. TXNIP was a downstream target gene of miR-128-3p. TXNIP was highly expressed in the DR cell model. Rescue assays revealed that circFTO promoted angiogenesis and impaired the blood-retinal barrier by upregulating TXNIP. In the DR mouse model, circFTO silencing inhibited angiogenesis and promoted BRB recovery in vivo. Conclusion: CircFTO promotes angiogenesis and impairs the blood-retinal barrier in vitro and in vivo by binding with miR-128-3p to upregulate TXNIP in DR.