Hsa_circ_0031891 targets miR-579-3p to enhance HMGB1 expression and regulate PDGF-BB-induced human aortic vascular smooth muscle cell proliferation, migration, and dedifferentiation

Atherosclerosis (AS) is an underlying cause of the majority of coronary artery disease (CAD), in which proliferation, migration, and dedifferentiation of vascular smooth muscle cells (VSMCs) exert vital roles. It has been reported that circular RNAs (circRNAs) are associated with the VSMCs function. Here, we undertook to explore the biological function and mechanism of hsa_circ_0031891 in a platelet-derived growth factor-BB (PDGF-BB)-induced AS cell model. Hsa_circ_0031891 and microRNA-579-3p (miR-579-3p) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation and migration were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), wound healing, and transwell assay. Protein levels of alpha-smooth muscle actin (α-SMA), smooth muscle protein 22-α (SM22-α), Osteopontin, and High mobility group box-1 (HMGB1) were determined using western blot assay. After predicting via a variety of bioinformatics software, the binding between miR-579-3p and hsa_circ_0031891 or HMGB1 was validated using dual-luciferase reporter and RNA pull-down assays. Increased hsa_circ_0031891 and HMGB1 and reduced miR-579-3p were found in CAD patients and PDGF-BB-induced human aortic vascular smooth muscle cells (HA-VSMCs). Moreover, hsa_circ_0031891 deficiency relieved PDGF-BB-mediated HA-VSMC proliferation, migration, and dedifferentiation. Mechanically, hsa_circ_0031891 modulated HMGB1 expression via sponging miR-579-3p. Hsa_circ_0031891 boosted PDGF-BB-induced proliferation, migration, and dedifferentiation partly by regulating the miR-579-3p/HMGB1 axis, hinting at a feasible therapeutic strategy for AS.

Brain microvascular endothelial cell-derived exosomes transmitting circ_0000495 promote microglial M1-polarization and endothelial cell injury under hypoxia condition

Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1β, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1β), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.

Circ_0059662 exerts a positive role in oxygen-glucose deprivation/reoxygenation-induced SK-N-SH cell injury

Circular RNA (circRNA) is identified as a potential regulator of ischemic stroke (IS) progression. Through GEO database screening, it was found that circ_0059662 was highly expressed in acute IS patients. However, whether circ_0059662 participated in the IS process has not been studied. Oxygen-glucose deprivation/reoxygenation (OGD/R)-induced SK-N-SH cells were established to mimic IS cell models. The expression of circ_0059662, miR-579-3p, and ETS proto-oncogene 1 (ETS1) was measured via quantitative real-time PCR. Cell counting kit 8 assay, EdU assay and flow cytometry were utilized to detect cell proliferation and apoptosis. Western blot was employed to measure protein expression. ELISA was used to detect the levels of inflammation factors, and oxidative stress was determined by assessing SOD activity and MDA level. The relationship between miR-579-3p and circ_0059662 or ETS1 was examined via dual-luciferase reporter assay, RNA pull-down assay and RIP assay. Circ_0059662 was a circular RNA with highly expression in OGD/R-induced SK-N-SH cells. In OGD/R-induced cell injury, circ_0059662 knockdown promoted cell proliferation, and inhibited cell apoptosis, inflammation and oxidative stress. Circ_0059662 served as miR-579-3p sponge to positively regulate ETS1 expression. MiR-579-3p inhibitor and ETS1 overexpression could reverse the inhibition effect of circ_0059662 knockdown on OGD/R-induced cell injury. Besides, MiR-579-3p also could relieve OGD/R-induced SK-N-SH cell apoptosis, inflammation and oxidative stress by targeting ETS1. Our findings indicated that circ_0059662 knockdown alleviated OGD/R-induced SK-N-SH cell injury by sponging miR-579-3p to regulate ETS1 expression.

Circ_0007706 downregulation ameliorates neonatal hypoxic ischemic encephalopathy via regulating the miR-579-3p/TRAF6 axis

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) is a main factor of neonatal death and permanent neurologic deficit. This study sought to investigate the functional role of hsa_circ_0007706 (circ_0007706) in modulating neonatal HIE.

METHODS

In vitro HIE cell model was established in hBMVECs under the condition of oxygen‑glucose deprivation/reperfusion (OGD/R) treatment. qRT-PCR analysis was utilized for detecting the level of circ_0007706, microRNA-579-3p (miR-579-3p) and TNF receptor-associated factor 6 (TRAF6). RNase R treatment and Oligo (dT) ₁₈ primers were employed to verify the features of circ_0007706, and nucleocytoplasmic separation was conducted for determining the location of circ_0007706. CCK-8 assay, EdU assay, and flow cytometry were carried out to measure cell proliferation and apoptosis, respectively. The protein expression of Bax, Bcl-2 and TRAF6 was detected using western blot. Meanwhile, the levels of the pro-inflammatory factors were determined via ELISA. SOD activity and MDA level were assessed via the respective kits. Besides, dual-luciferase reporter assay and RNA pull-down were used to identify the association between miR-579-3p and circ_0007706 or TRAF6.

RESULTS

Circ_0007706 was elevated in HIE newborns and OGD/R cell model. Knockdown of circ_0007706 greatly alleviated OGD/R-induced injury, inflammatory response and oxidative stress. We found that miR-579-3p was a direct target of circ_0007706, and miR-579-3p inhibitor could reverse the impact of circ_0007706 knockdown on OGD/R-caused cell damage in hBMVECs. In addition, miR-579-3p directly interacted with TRAF6, and the protective effects of miR-579-3p on OGD/R-induced injury in hBMVECs were harbored by TRAF6 overexpression. Our data indicated that circ_0007706 knockdown could downregulate the expression of TRAF6 by sponging miR-579-3p in OGD/R-treated hBMVECs.

CONCLUSION

This study demonstrated that circ_0007706 knockdown assuaged HIE-induced injury by decreasing TRAF6 expression via targeting miR-579-3p.

Circ_0000182 promotes cholesterol synthesis and proliferation of stomach adenocarcinoma cells by targeting miR-579-3p/SQLE axis

BACKGROUND

Circular RNAs (circRNAs) or cholesterol metabolism have been demonstrated to participate in stomach adenocarcinoma (STAD) progression. However, the relationship between circRNAs and cholesterol metabolism in STAD and its underlined mechanism remain unclear.

METHODS

RNA and protein expression levels were detected by qRT-PCR and Western blot. Cell proliferation was assessed by CCK-8, EdU incorporation and colony formation assays. Total cholesterol (TC) and free cholesterol (FC) levels were measured by the corresponding kits. The relationships between circ_0000182 and miR-579-3p or squalene epoxidase (SQLE) mRNA were investigated by bioinformatics analysis, RNA-RNA pull-down, luciferase reporter and RIP assays.

RESULTS

We found that circ_0000182 expression was significantly up-regulated in both STAD tissues and cell lines, and high circ_0000182 expression was correlated with increased tumor size. Circ_0000182 promoted cell proliferation and cholesterol synthesis of STAD cells. Accordingly, cell proliferation, cholesterol synthesis and SQLE expression were significantly inhibited by circ_0000182 knockdown in STAD cells, and these effects were partly reversed by miR-579-3p inhibition or SQLE over-expression. Furthermore, we identified that circ_0000182 acted as a competing endogenous RNA (ceRNA) by sponging miR-579-3p, thereby facilitating SQLE expression, cholesterol synthesis and cell proliferation.

CONCLUSION

Circ_0000182 promotes cholesterol synthesis and proliferation of STAD cells by enhancing SQLE expression via sponging miR-579-3p.

GUSBP11 Inhibited The Progression of Triple Negative Breast Cancer via Targeting The miR-579-3p/SPNS2 Axis

OBJECTIVE

Growing evidences have exposed the important roles of long noncoding RNAs (lncRNAs) in the triple negative breast cancer (TNBC) inhibition. The function of glucuronidase beta pseudogene 11 (GUSBP11) in the TNBC occurrence remains obscure. To detect the function of GUSBP11 in TNBC progression and explore its downstream molecular mechanism.

MATERIALS AND METHODS

In this experimental study, using quantitative reverse transcription real-time polymerase chain reaction (RT-qPCR), we measured the GUSBP11 expression in the TNBC cell lines. Gain-of-function assays, including colony formation, flow cytometry, and western blot were used to identify the probable effects of GUSBP11 overexpression on the malignant behaviors of TNBC cell lines. Moreover, mechanism assays, including RNA immunoprecipitation (RIP), RNA pull down and luciferase reporter assays were taken to measure the possible mechanism of GUSBP11 in the TNBC cell lines.

RESULTS

GUSBP11 expressed at a low RNA level in the TNBC cell lines. Overexpression of GUSBP11 RNA expression inhibited the proliferation, migration, epithelial-to-mesenchymal transition (EMT) and stemness while elevated the apoptosis of the TNBC cell lines. GUSBP11 positively regulated the expression of sphingolipid transporter 2 (SPNS2) via acting as a competing endogenous RNA (ceRNA) of miR-579-3p, thereby suppressing the development of TNBC cell lines.

CONCLUSION

GUSBP11 impedes TNBC progression via modulating the miR-579-3p/SPNS2 axis.

Circ_0001093 promotes glutamine metabolism and cancer progression of esophageal squamous cell carcinoma by targeting miR-579-3p/glutaminase axis

Increasing studies indicate that circular RNAs (circRNAs) play critical roles in tumor metabolism of multiple cancers. However, the contribution of circRNAs in glutamine metabolism of esophageal squamous cell carcinoma (ESCC) remains elusive. The objective of this research was to investigate the role and mechanism of circRNA hsa_circ_0001093 (circ_0001093) in the glutamine metabolism and tumorigenesis of ESCC. Circ_0001093, microRNA-579-3p (miR-579-3p) and glutaminase (GLS) expressions in ESCC tissues and cell lines were measured by qRT-PCR, tissue array or Western blot. Cell proliferation, invasion and migration were assessed by CCK-8 or transwell assays. Glutamine consumption, glutamate and ATP production were detected by indicated assay kits. The relationships between circ_0001093 and miR-579-3p or GLS mRNA were investigated by bioinformatics analysis, RNA pull-down, luciferase reporter and RNA immunoprecipitation (RIP) assays. Here, we found that circ_0001093 expression was up-regulated in ESCC tissues and cell lines. Increased circ_0001093 expression predicted an unfavourable prognosis, and was associated with the lymph node metastasis, TNM staging and tumor size in ESCC tissues. Circ_0001093 knockdown suppressed cell proliferation, invasion, migration and glutamine metabolism of ESCC cells, while circ_0001093 over-expression showed the opposite effects. Mechanistically, circ_0001093 acted as a competing endogenous RNA (ceRNA) by sponging miR-579-3p, thereby increasing GLS expression. Furthermore, the inhibitory effects of circ_0001093 knockdown on the invasion, migration and glutamine metabolism were partly rescued by miR-579-3p inhibition or GLS over-expression in ESCC cells. Additionally, miR-579-3p expression was down-regulated in ESCC tissues, while GLS expression was up-regulated. In conclusion, this study first provides evidence that the circ_0001093/miR-579-3p/GLS regulatory network can affect glutamine metabolism and malignant phenotype of ESCC, which can further impact ESCC progression.

Circ_0001490/miR-579-3p/FSTL1 axis modulates the survival of mycobacteria and the viability, apoptosis and inflammatory response in Mycobacterium tuberculosis-infected macrophages

BACKGROUND

Macrophages play an important role in the host immune response against mycobacterial infection, and this process is regulated by various factors, including circular RNAs (circRNAs). We intended to explore the role of circ_0001490 in tuberculosis (TB) using Mycobacterium tuberculosis (M.tb)-infected THP-1 macrophages.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were conducted to measure RNA and protein expression, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to analyze the viability of THP-1 macrophages. Flow cytometry was performed to analyze the apoptosis rate of THP-1 macrophages. Enzyme-linked immunosorbent assay (ELISA) was conducted to assess the release of inflammatory cytokines. Colony-forming unit (CFU) assay was conducted to analyze the survival of M.tb in THP-1 macrophages. Intermolecular target interaction was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

RESULTS

Circ_0001490 expression was down-regulated in the serum samples of TB patients and M.tb-infected THP-1 macrophages. Circ_0001490 overexpression suppressed M.tb survival and promoted the viability and inflammatory response of THP-1 macrophages. Circ_0001490 interacted with microRNA-579-3p (miR-579-3p), and circ_0001490 overexpression-induced protective effects in M.tb-infected THP-1 macrophages were largely overturned by the overexpression of miR-579-3p. miR-579-3p interacted with the 3' untranslated region (3'UTR) of follistatin-like protein 1 (FSTL1). FSTL1 silencing largely overturned miR-579-3p knockdown-induced effects in M.tb-infected THP-1 macrophages. Circ_0001490 acted as miR-579-3p sponge to up-regulate FSTL1 in THP-1 macrophages.

CONCLUSION

In conclusion, our results demonstrated that circ_0001490 suppressed M.tb survival and promoted the viability and inflammatory response of M.tb-infected THP-1 macrophages partly by regulating miR-579-3p/FSTL1 axis.

Expression of LINC01606 in multiple myeloma and its effect on cell invasion and migration

Given the increasing incidence of multiple myeloma (MM) in recent years, a full understanding of its pathogenesis to find effective molecular markers carries huge implications for future clinical diagnosis and treatment of MM. As the research advances, accumulating studies have pointed out that long non-coding RNAs (LncRNAs) may be the key to the future diagnosis and treatment of neoplastic diseases.

OBJECTIVE

This study investigated the clinical implications of LncRNA LINC01606 in MM and its effects on the biological behavior of MM cells.

METHODS

In this prospective study, 72 patients with MM (group A) admitted between July 2014 and July 2016 and 68 healthy subjects (group B) who concurrently underwent physical examination in our hospital were included. The expression of LINC01606 in peripheral blood of patients in the two groups was detected to analyze its diagnostic and prognostic value in MM. In addition, MM cells were purchased and transfected with plasmids for mimics, inhibitors and negative control of LINC01606 and miR-579-3p respectively to detect the changes in cell proliferation, invasion and migration.

RESULTS

The expression of LINC01606 in group A was higher than that in group B (P<0.050). The sensitivity and specificity of peripheral blood LINC01606 in predicting MM were 85.29% and 72.39%, respectively (P<0.001). Prognostic follow-up analysis revealed higher LINC01606 levels in the dead than those in the survival. The predictive sensitivity of LINC01606 for the 3-year mortality of MM patients was 63.16%, and the specificity was 86.00% (P<0.001). Higher expression of LINC01606 indicated increased risk of 3-year mortality in patients with MM (P<0.001). Compared with LINC01606 overexpression and miR-579-3p inhibition, the proliferation, invasion and migration of cells decreased more significantly by LINC01606 inhibition and miR-579-3p overexpression (P<0.050). Dual luciferase reporter (DLR) assay confirmed the targeting relationship between LINC01606 and miR-579-3p. There was no significant difference in the activity of MM cells co-transfected with LINC01606-inhibitor and miR-579-3p-inhibitor plasmids compared with the blank group (P>0.050).

CONCLUSIONS

LINC01606, with a high expression profile in MM, promotes the proliferation, migration and invasion of MM cells through targeted inhibition of miR-579-3p, which may be the key to future diagnosis and treatment of MM.

LncRNA GAS5 inhibits miR-579-3p to activate SIRT1/PGC-1α/Nrf2 signaling pathway to reduce cell pyroptosis in sepsis-associated renal injury

Sepsis is a life-threatening condition that can lead to several organ failures including kidney. In this study, we investigated the roles of GAS5 and miR-579-3p in regulating cell pyroptosis in the sepsis-induced renal injury model. Lipopolysaccharide (LPS) treatment or cecal ligation and puncture (CLP) surgery was used to create the in vitro and in vivo sepsis-induced renal injury model. The interactions between GAS5 and miR-579-3p, and miR-579-3p and SIRT1 were determined by bioinformatic prediction, luciferase reporter assay, and RIP assay. In vitro cell pyroptosis was examined by flow cytometry marked with active caspase-1 and PI. The protein levels of IL-1β and IL-18 induced by cell pyroptosis were quantified using ELISA assay. In vivo renal injuries were evaluated with HE and TUNEL stainings, bacterial load in serum and creatinine, and blood urea nitrogen content analyses. Expression levels of GAS5, miR-579-3p, pyroptosis, and SIRT1/PGC-1a/Nrf2 pathway-related molecules were evaluated by qRT-PCR or Western blot. GAS5 and SIRT1 were downregulated, whereas miR-579-3p was upregulated in in vitro and in vivo sepsis-induced renal injury models. GAS5 negatively and directly regulated miR-579-3p to reduce cell pyroptosis via the activation of SIRT1/PGC-1a/Nrf2 pathway. In addition, miR-579-3p suppressed PGC-1a/Nrf2 pathway to induce cell pyroptosis by directly targeting SIRT1. What's more, overexpression of GAS5, or knockdown of miR-579-3p, enhanced SIRT1 expression that led to the improved survival rate, reduced the weight loss, and relieved renal injuries in septic mice. Overexpression of GAS5 demonstrated protective effects against sepsis-induced renal injury via downregulating miR-579-3p and activating SIRT1/PGC-1α/Nrf2 pathway to inhibit cell pyroptosis.

MicroRNA-579-3p Exerts Neuroprotective Effects Against Ischemic Stroke via Anti-Inflammation and Anti-Apoptosis

BACKGROUND/AIMS

Multiple studies have found that microRNAs (miRNAs) are involved in the development of cerebral ischemia. MiR-579-3p can inhibit inflammatory responses and apoptosis, leading to ischemia/reperfusion (I/R) damage. However, the mechanism of how miR-579-3p actions in brain I/R injury remains unclear. This study aimed to investigate the mechanism of the role of miR-579-3p in brain I/R injury.

METHODS

A rat model of cerebral ischemia-reperfusion injury was established by suture method. The effects of miR-579-3p on cerebral infarction size, brain water content, and neurological symptoms were evaluated. Flow cytometry was used to detect apoptosis. ELISA was used to detect the level of inflammatory factors. Western blot was used to detect the expression of P65, NCOA1, Bcl-2 and Bax. The relationship between miR-579-3p and NCOA1 was analyzed by bioinformatics analysis and luciferase assay.

RESULTS

Overexpression of miR-579-3p reduced infarct volume, brain water content and neurological deficits. Overexpression of miR-579-3p inhibited the expression level of the inflammatory cytokines, such as TNF-α, IL-6, COX-2 and iNOS, and increased the expression level of IL-10. MiR-579-3p overexpression inhibited NF-кB activity by reducing NRIP1. In addition, miR-579-3p could reduce the apoptotic rate of cortical neurons. Overexpression of miR-579-3p inhibited the activity of caspase-3, increased the expression level of anti-apoptotic gene Bcl-2 in neurons, and decreased the expression level of apoptotic gene Bax.

CONCLUSION

miR-579-3p can be used to treat brain I/R injury, and its neuroprotective effect may be ascribed to the reduction of inflammation and apoptosis.

Targeting signal-transducer-and-activator-of-transcription 3 sensitizes human cutaneous melanoma cells to BRAF inhibitor

Melanoma treatment with the BRAF V600E inhibitor vemurafenib provides therapeutic benefits but the common emergence of drug resistance remains a challenge. To define molecular mechanisms of vemurafenib resistance, we generated A375-R, WM35-R cell lines resistant to vemurafenib and show that the phosphorylated (p)-STAT3 was upregulated in these cells in vitro and in vivo. In particular, activation of the Signal-transducer-and-activator-of-transcription 3 (STAT3) pathway was associated with vemurafenib resistance. Inhibition of this pathway with STAT3-specific siRNA (shRNA) sensitized A375-R, WM35-R cells to vemurafenib and induced apoptosis in vitro and in vivo. Moreover, targeting STAT3 induced expression of miR-579-3p and elicited resistance to vemurafenib. However, targeting microRNA (miR)-579-3p with anti-miR-579-3p reversed the resistance to vemurafenib. Together, these results indicated that STAT3-mediated downexpression of miR-579-3p caused resistance to vemurafenib. Our findings suggest novel approaches to overcome resistance to vemurafenib by combining vemurafenib with STAT3 sliencing or miR-579-3p overexpression.

Targeting STAT3 restores BRAF inhibitor sensitivity through miR-759-3p in human cutaneous melanoma cells

Melanoma treatment with the BRAF V600E inhibitor vemurafenib provides therapeutic benefits, but the common emergence of drug resistance remains a challenge. To define molecular mechanisms of vemurafenib resistance, we generated A375-R, WM35-R cell lines resistant to vemurafenib and found that the p-STAT3 was upregulated in these cells in vitro and in vivo. In particular, activation of the STAT3 pathway was associated with vemurafenib resistance. Inhibition of this pathway with STAT3-specific siRNA (shRNA) sensitized A375-R, WM35-R cells to vemurafenib and induced apoptosis in vitro and in vivo. Moreover, targeting STAT3 induced expression of miR-579-3p and elicited resistance to vemurafenib. However, targeting miR-579-3p with anti- miR-579-3p reversed the resistance to vemurafenib. Together, these results indicate that STAT3-mediated downexpression of miR-579-3p caused resistance to vemurafenib. Our findings suggest novel approaches to overcome resistance to vemurafenib by combining vemurafenib with STAT3 silencing or miR-579-3p overexpression.