MiR-497-5p ameliorates the oxyhemoglobin-induced subarachnoid hemorrhage injury in vitro by targeting orthodenticle homeobox protein 1 (Otx1) to activate the Nrf2/HO-1 pathway.

Subarachnoid hemorrhage (SAH) is a neurological disorder that severely damages the brain and causes cognitive impairment. MicroRNAs are critical regulators in a variety of neurological diseases. MiR-497-5p has been found to be downregulated in the aneurysm vessel walls obtained from patients with aneurysmal subarachnoid hemorrhage, but its functions and mechanisms in SAH have not been reported. Therefore, this study was designed to investigate the effect of miR-497-5p and its related mechanisms in SAH. We established an in vitro SAH model by exposing PC12 cells to oxyhemoglobin (oxyHb). We found that miR-497-5p was downregulated in SAH serum and oxyHb-treated PC12 cells, and its overexpression inhibited the oxyHb-induced apoptosis, inflammatory response and oxidative stress via activation of the Nrf2 pathway. Mechanistically, the targeting relationship between miR-497-5p and Otx1 was verified by luciferase reporter assays. Moreover, Otx1 upregulation abolished the protective effects of miR-497-5p upregulation against oxyHb-induced apoptosis, inflammation and oxidative stress in PC12 cells. Collectively, our findings indicate that miR-497-5p could inhibit the oxyHb-induced SAH damage by targeting Otx1 to activate the Nrf2/HO-1 pathway, which provides a potential therapeutic target for SAH treatment.

The mechanism of lncRNA SNHG1 in osteogenic differentiation via miR-497-5p/ HIF1AN axis.

The pivotal role of lncRNAs in osteoporosis progression and development necessitates a comprehensive exploration of the functional and precise molecular mechanisms underlying lncRNA SNHG1's regulation of osteoblast differentiation and calcification. The study involved inducing BMSCs cells to differentiate into osteoblasts, followed by transfections of miR-497-5p inhibitors, pcDNA3.1-SNHG1, sh-HIF1AN, miR-497-5p mimics, and respective negative controls into BMSCs. Quantitative PCR (qPCR) was employed to assess the expression of SNHG1 and miR-497-5p. Western Blotting was conducted to measure the levels of short stature-related transcription factor 2 (RUNX2), osteopontin (OPN), osteocalcin (OCN), and HIF1AN. Alkaline phosphatase (ALP) activity was determined using appropriate assay kits. Calcium nodule staining was performed through Alizarin red staining. Dual luciferase reporter gene assays were executed to validate the interaction between SNHG1 and miR-497-5p, as well as HIF1AN. Throughout osteogenic differentiation, there was a down-regulation of SNHG1 and HIF1AN, in contrast to an elevation in miR-497-5p levels. Direct interactions between miR-497-5p and both SNHG1 and HIF1AN were observed. Notably, SNHG1 exhibited the ability to modulate HIF1AN by influencing miR-497-5p, thereby inhibiting osteogenic differentiation. Functioning as a competitive endogenous RNA, lncRNA SNHG1 exerts an inhibitory influence on osteogenic differentiation via the miR-497-5p/HIF1AN axis. This highlights the potential for lncRNA SNHG1 to emerge as a promising therapeutic target for osteoporosis. The study's findings pave the way for a novel target strategy in the future treatment of osteoporosis.

METTL14-mediated lncRNA XIST silencing alleviates GDM progression by facilitating trophoblast cell proliferation and migration via the miR-497-5p/FOXO1 axis.

Gestational diabetes mellitus (GDM), a prevalent complication during the gestation period, has been linked to impaired proliferation and migration of trophoblasts causing placental maldevelopment. We previously found that lncRNA X-inactive specific transcript (XIST) played an essential role in GDM progression. Here, we investigated the precise biological functions as well as the upstream and downstream regulatory mechanisms of XIST in GDM. We found that XIST and forkhead box O1 (FOXO1) were conspicuously upregulated and miR-497-5p and methyltransferase-like 14 (METTL14) were downregulated in the placentas of GDM patients. XIST silencing facilitated proliferation and migration and inhibited cell apoptosis and cell cycle arrest in HG-cultured HTR8/SVneo cells. METTL14 inhibited XIST expression through m6A methylation modification. XIST overexpression abrogated the positive effect of METTL14 overexpression on HG-cultured HTR8/SVneo cell progression. MiR-497-5p and FOXO1 are downstream regulatory genes of XIST in HTR8/SVneo cells. Reverse experiments illustrated that XIST mediated HTR8/SVneo cell functions by regulating the miR-497-5p/FOXO1 axis. Additionally, XIST silencing augmented glucose tolerance and alleviated fetal detrimental changes in GDM rats. To conclude, METTL14-mediated XIST silencing facilitated proliferation and migration and inhibited cell apoptosis and cell cycle arrest in HG-cultured HTR8/SVneo cells via the miR-497-5p/FOXO1 axis, thereby alleviating GDM progression in rats.

LncRNA TRPM2-AS promotes endometrial carcinoma progression and angiogenesis via targeting miR-497-5p/SPP1 axis.

BACKGROUND: Anti-angiogenic therapy has become one of the effective treatment methods for tumors. Long noncoding RNAs (lncRNAs) are emerging as important regulators of tumorigenesis and angiogenesis in EC. However, the underlying mechanisms of lncRNA TRPM2-AS in EC are still not clear. METHODS: We screened the differently expressed lncRNAs that were highly associated with poor prognosis and angiogenesis of EC by bioinformatics analysis, and constructed a ceRNA network based on the prognostic lncRNAs. The subcellular localization of TRPM2-AS was determined by fluorescence in situ hybridization (FISH) and nuclear cytoplasmic fractionation assay. CCK-8, EdU, transwell, western blot, qRT-PCR and endothelial tube formation assay were used to evaluate the effects of TRPM2-AS on the proliferation, invasion, migration of EC cells and angiogenesis. The targeted microRNA (miRNA) of TRPM2-AS was predicted by bioinformatic methods. The interaction between TRPM2-AS and miR497-5p, miR497-5p and SPP1 were analyzed by RNA immunoprecipitation and dual-luciferase reporter assay. A subcutaneous tumor model was used to explore TRPM2-AS's function in vivo. CIBERSORT was used to analyze the correlation between TRPM2-AS and immune cell immersion in EC. RESULTS: We found that the expression of TRPM2-AS and SPP1 was aberrantly upregulated, while miR-497-5p expression was significantly downregulated in EC tissues and cells. TRPM2-AS was closely correlated with the angiogenesis and poor prognosis in EC patients. Mechanistically, TRPM2-AS could sponge miR-497-5p to release SPP1, thus promoting the proliferation, invasion and migration of EC cells and angiogenesis of HUVECs. Knockdown of TRPM2-AS in xenograft mouse model inhibited tumor proliferation and angiogenesis in vivo. In addition, TRPM2-AS plays a vital role in regulating the tumor immune microenvironment of EC, overexpression of TRPM2-AS in EC cells stimulated the polarization of M2 macrophages and angiogenesis through secreting SPP1 enriched exosomes. CONCLUSION: The depletion of TRPM2-AS inhibits the oncogenicity of EC by targeting the miR-497-5p/SPP1 axis. This study offers a better understanding of TRPM2-AS's role in regulating angiogenesis and provides a novel target for EC treatment.

The mechanism and therapeutic potential of lncRNA MIR497HG/miR-16-5p axis in breast cancer.

BACKGROUND: Breast cancer has become a major public health problem in the current society, and its incidence rate ranks the first among Chinese female malignant tumors. This paper once again confirmed the efficacy of lncRNA in tumor regulation by introducing the mechanism of the diagnosis of breast cancer by the MIR497HG/miR-16-5p axis. METHODS: The abnormal expression of MIR497HG in breast cancer was determined by RT-qPCR method, and the correlation between MIR497HG expression and clinicopathological characteristics of breast cancer patients was analyzed via Chi-square test. To understand the diagnostic potential of MIR497HG in breast cancer by drawing the receiver operating characteristic curve (ROC). The overexpressed MIR497HG (pcDNA3.1-MIR497HG) was designed and constructed to explore the regulation of elevated MIR497HG on biological function of BT549 and Hs 578T cells through Transwell assays. Additionally, the luciferase gene reporter assay and Pearson analysis evaluated the targeting relationship of MIR497HG to miR-16-5p. RESULTS: MIR497HG was decreased in breast cancer and had high diagnostic function, while elevated MIR497HG inhibited the migration and invasion of BT549 and Hs 578T cells. In terms of functional mechanism, miR-16-5p was the target of MIR497HG, and MIR497HG reversely regulated the miR-16-5p. miR-16-5p mimic reversed the effects of upregulated MIR497HG on cell biological function. CONCLUSIONS: In general, MIR497HG was decreased in breast cancer, and the MIR497HG/miR-16-5p axis regulated breast cancer tumorigenesis, providing effective insights for the diagnosis of patients.

MiR-497-3p induces Premature ovarian failure by targeting KLF4 to inactivate Klotho/PI3K/AKT/mTOR signaling pathway.

BACKGROUND: Premature ovarian failure (POF), as a gynecological endocrine disease, features the manifestation of irregular menstruation, amenorrhea, infertility and perimenopausal syndrome. MicroRNAs (miRNAs) have been reported to modulate POF. However, the specific regulatory mechanism of miR-497-3p in POF remain unclear. METHODS: Quantitative reverse transcription-PCR (RT-qPCR) and western blot were implemented to analyze RNA and protein levels, respectively. Comet assay was performed for the detection of DNA damage. Flow cytometry analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to measure apoptosis of CTX-induced KGN cell (POF cell model). Bioinformatics was utilized to screen out the downstream mRNAs potentially regulated by miR-497-3p. Chromatin immunoprecipitation (ChIP) assay, luciferase reporter assay and RNA pulldown assays were performed to demonstrate the interaction between miR-497-3p and Kruppel-like factor 4 (KLF4) or between KLF4 and Klotho (KL). Rescue assays were performed to verify the involvement of Klotho in miR-497-3p-mediated functions of POF cell model. RESULTS: MiR-497-3p was upregulated in CTX-treated KGN cells. Knockdown of miR-497-3p could reverse the promoting effects of CTX on DNA damage and cell apoptosis. MiR-497-3p negatively regulated Klotho expression by directly targeting the transcription activator KLF4. KLF4 activated Klotho transcription. MiR-497-3p inactivated PI3K/AKT/mTOR signaling pathway through KLF4/Klotho axis. Klotho knockdown reversed the effects of MiR-497-3p on the functions of POF cell model. CONCLUSION: MiR-497-3p promotes DNA damage and apoptosis in CTX-treated KGN cells by targeting KLF4 to downregulate Klotho and inactivate the PI3K/AKT/mTOR signaling pathway. This study unveils novel mechanisms associated with cell functional changes in POF and may enrich therapeutic strategy for POF.

Alleviative effect of microRNA-497 on diabetic neuropathic pain in rats in relation to decreased USP15.

The current study tries to discuss the functional role of microRNA-497 (miR-497) in diabetic neuropathic pain (DNP) and the related downstream mechanism. Bioinformatics analysis was implemented for the identification of differentially expressed miRNAs and genes. DNP was simulated in rats through intraperitoneal injection of streptozotocin. The expression patterns of miR-497, USP15, NRF2, and G6PD were then determined. The binding of miR-497 and USP15 was confirmed. Using gain- and loss-of-function assays, we analyzed the critical role of miR-497-mediated USP15 in DNP through the NRF2/G6PD axis. Downregulated miR-497 and elevated USP15 were observed in the dorsal root ganglion neurons isolated from spinal cord tissues of STZ-induced DNP rats. miR-497 could alleviate DNP, which was associated with suppression of USP15, a confirmed target of miR-497. USP15 enhanced the degradation and ubiquitination of NRF2 and induced G6PD expression, leading to the progression of DNP. We highlighted the crucial role of miR-497-mediated USP15 in DNP through the NRF2/G6PD axis. 1. miR-497 is downregulated in DRG neurons from spinal cord tissues of STZ-induced DNP rats. 2. miR-497 inhibits the expression of USP15, thereby alleviating STZ-induced DNP in rats. 3. USP15 promotes ubiquitination and degradation of NRF2, reducing the expression of G6PD. 4. miR-497 alleviates STZ-induced DNP in rats by regulating the USP15/NRF2/G6PD axis.

Hypermethylation of microRNA-497-3p contributes to progression of thyroid cancer through activation of PAK1/ß-catenin.

MicroRNA-497 (miR-497) has been reported to be a tumor-suppressive miRNA in thyroid cancer (TC), yet the mechanism is not clearly defined. In this study, we aim to determine the mechanism by which miR-497-3p affects the progression of TC. After characterization of low miR-497-3p expression pattern in TC and normal tissues, we assessed the correlation between miR-497-3p expression and clinicopathological features of TC patients. Its low expression shared associations with advanced tumor stage and lymph node metastasis. ChIP and methylation-specific PCR provided data showing that downregulation of miR-497-3p in TC tissues was induced by DNA methyltransferase-mediated hypermethylation. By performing dual-luciferase reporter assay, we identified that miR-497-3p targeted PAK1 while PAK1 could inhibit ß-catenin expression. Through this mechanism, miR-497-3p exerted the anti-proliferative, anti-invasive, pro-apoptotic, and anti-tumorigenic effects on TC cells on the strength of the results from gain-of-function and rescue experiments. This study suggested that hypermethylation of miR-497-3p resulted in upregulation of ß-catenin dependent on PAK1 and contributed to cancer progression in TC, which highlighted one of miR-mediated tumorigenic mechanism.

Circ_001422 aggravates osteosarcoma progression through targeting miR-497-5p/E2F3 axis.

Circular RNAs exert vital functions in the pathogenesis of osteosarcoma (OS). Circ_001422 has been confirmed to be involved in regulating OS progression, but its specific mechanism has not been clearly studied. This work aimed to analyze circ_001422's role in OS cell biological behaviors and the possible molecular mechanisms. This work carried out reverse transcription-quantitative polymerase chain reaction for detecting circ_001422, E2F3 and miR-497-5p levels, whereas Cell counting kit-8 together with Transwell assays for measuring cell growth, migration as well as invasion abilities. Relation of miR-497-5p with E2F3, as well as circ_001422 with miR-497-5p was analyzed through dual-luciferase reporter gene assay. Protein level was identified by western blot. According to our results, circ_001422 expression within OS tissue significantly increased compared with corresponding healthy samples. Inhibition of circ_001422 significantly decreased OS cell growth, invasion and migration. From mechanism research, miR-497-5p was proved as circ_001422's target, and E2F3 was miR-497-5p's target. Besides, miR-497-5p downregulation or E2F3 overexpression abolished circ_001422 inhibition-mediated inhibition on OS cell proliferation, invasion and migration. Collectively, this study has first suggested circ_001422's role in enhancing OS proliferation, migration as well as invasion via miR-497-5p/E2F3 axis. Our results will offer new ideas and new anti-OS targets.

LncRNA SNHG14/miR-497a-5p/BACE1 axis modulates obesity-induced adipocyte inflammation and endoplasmic reticulum stress.

Obesity is a metabolic disease with excess weight. LncRNA SNHG14 is abnormally expressed in numerous diseases. This research aimed to enucleate the lncRNA SNHG14 role in obesity. Adipocytes were treated with free fatty acid (FFA) to establish an in vitro model for obesity. Mice were fed a high-fat diet to construct an in vivo model. Gene levels were determined using quantitative real-time PCR (RT-PCR). The protein level was checked by western blot. The lncRNA SNHG14 role in obesity was assessed using western blot and enzyme-linked immunosorbent assay. The mechanism was estimated by Starbase, dual-luciferase reporter gene assay, and RNA pull-down. LncRNA SNHG14 function in obesity was estimated using mouse xenograft models, RT-PCR, western blot, and enzyme-linked immunosorbent assay. LncRNA SNHG14 and BACE1 levels were increased, but the miR-497a-5p level was decreased in FFA-induced adipocytes. Interference with lncRNA SNHG14 reduced endoplasmic reticulum (ER) stress-related molecules GRP78 and CHOP expressions in FFA-induced adipocytes, and decreased IL-1ß, IL-6, and TNF-α expressions, indicating that lncRNA SNHG14 knockdown mitigated FFA-induced ER stress and inflammation in adipocytes. Mechanistically, lncRNA SNHG14 combined with miR-497a-5p, and miR-497a-5p targeted BACE1. Meanwhile, lncRNA SNHG14 knockdown reduced levels of GRP78, CHOP, IL-1ß, IL-6, and TNF-α, while cotransfection with anti-miR-497a-5p or pcDNA-BACE1 abolished these trends. Rescue assays illustrated that lncRNA SNHG14 knockdown relieved FFA-induced adipocyte ER stress and inflammation through miR-497a-5p/BACE1. Meanwhile, lncRNA SNHG14 knockdown restrained adipose inflammation and ER stress caused by obesity in vivo. LncRNA SNHG14 mediated obesity-induced adipose inflammation and ER stress through miR-497a-5p/BACE1.

RBM12 regulates the progression of hepatocellular cancer via miR-497-5p/CPNE1 Axis.

BACKGROUND: Hepatocellular Carcinoma (HCC), also called hepatocellular cancer, has emerged as a highly prevalent malignancy globally. By binding to specific RNA via one or more spherical RNA Domains (RBDs) or RNA Motifs (RBMs), RNA Binding Proteins (RBPs) can affect RNA modification, splicing, localization, translation, and stability. METHODS: This paper builds on previous research by further investigating the impact of RBM12 on LC progression. In order to determine the effect of RBM12 expression on the prognosis of patients with hepatocellular cancer, we first investigated its expression in liver cancer cells (LCC) and tissues. The effect of RBM12 on the malignant biological behavior of LCC was subsequently detected using cytological experiments. To explore the upstream mechanism affecting RBM12, we predicted the miRNA targeting RBM12. According to the database, miR-497-5p was the best candidate gene. The double Luciferase reporter gene experiment was executed to validate the bounding of miR-497-5p with RBM12. RESULTS: According to the cytological experiments, a high RBM12 expression promoted the propagation, migration, and invasion of LCC and impeded liver cancer cell apoptosis. By secreting TGF-ß1, RBM12 could induce the EMT process. The miR-497-5p expression is suppressed in hepatocellular cancer. As shown by the CCK8, plate cloning, Transwell, EDU, and other experiments, miR-497-5p suppressed RBM12 expression and tumor growth. The double Luciferase reporter gene system was utilized to verify the combination of miR-497-5p and RBM12. The CPNE1 is a downstream gene regulated by RBM12. A high CPNE1 expression was exhibited in LCC and tissues. The CPNE1 is essential in the process where RBM12 promotes the incidence and progression of liver cancer. CONCLUSIONS: By elucidating the exact molecular mechanism through which RBM12 promotes the initiation and progression of LC, thus, the current investigation provides some reference for the clinical management of LC.

CircSOD2 Contributes to Tumor Progression, Immune Evasion and Anti-PD-1 Resistance in Hepatocellular Carcinoma by Targeting miR-497-5p/ANXA11 Axis.

Circular RNAs (circRNAs) can function as functional molecules in hepatocellular carcinoma (HCC). Herein, circRNA superoxide dismutase 2 (circSOD2) was researched in HCC progression and immune system. The real-time polymerase chain reaction (qRT-PCR) was used for quantification of circSOD2, microRNA-497-5p (miR-497-5p) and Annexin A11 (ANXA11). Cell assays were performed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and colony formation assays for proliferation, flow cytometry for apoptosis and cell cycle, wound healing assay for migration and transwell assay for migration/invasion. ANXA11 and metastatic protein levels were measured by western blot. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to analyze target binding. CD8+ T cell immunity was assessed by Immunohistochemistry (IHC) assay, and the effect of circSOD2 on programmed cell death 1 (PD-1) immune checkpoint inhibitors (anti-PD-1) therapy was evaluated by mice xenograft assay. CircSOD2 was upregulated in HCC tissues and cells. Knockdown of circSOD2 resulted in HCC cell growth inhibition, apoptosis promotion, cell cycle arrest and metastasis suppression. Mechanically, circSOD2 promoted HCC development by acting as a miR-497-5p sponge and miR-497-5p played a tumor-inhibitory role in HCC cells by targeting ANXA11. Moreover, circSOD2 induced upregulation of ANXA11 expression by interacting with miR-497-5p. Also, the promoting effects of circSOD2 on immune evasion and anti-PD-1 resistance were related to miR-497-5p/ANXA11 axis. This study elucidated the pivotal function of circSOD2 in HCC progression and immunosuppression by mediating miR-497-6p/ANXA11 axis. CircSOD2/miR-497-5p/ANXA11 axis was a novel view of circRNA research in HCC.

Long noncoding RNA CASC9 promotes pancreatic cancer progression by acting as a ceRNA of miR-497-5p to upregulate expression of CCND1.

BACKGROUND: Pancreatic cancer (PC) is an aggressive malignancy with poor prognosis. Accumulating studies have showed that long non-coding RNA (lncRNA) is a crucial regulator in various tumorigenesis and progression including PC. This research aims to explore the roles and molecular mechanism of lncRNA cancer susceptibility candidate 9 (CASC9) in PC. METHODS: The expression levels of lncRNA CASC9 and miR-497-5p were evaluated in PC tissues and paired adjacent healthy tissues by quantitative real-time PCR. PC cell lines were transfected with lentivirus targeting lncRNA CASC9, and cells proliferation, migration and invasion tests were conducted. Dual luciferase reporter assays were also carried out to explore the relationship between lncRNA CASC9, miR-497-5p and Cyclin D1 (CCND1). RESULTS: LncRNA CASC9 was significantly up-regulated in PC tissues, while miR-497-5p expression was down-regulated. Down-regulation of lncRNA CASC9 in PC cells can significantly suppress the cell aggressiveness both in vitro and in vivo; moreover, knock-down of miR-497-5p could neutralize this impact. Additionally, the luciferase activity assay has assured that CCND1 was a downstream target of miR-497-5p. CONCLUSION: LncRNA CASC9 can promote the PC progression by modulating miR-497-5p/CCND1 axis, which is potential target for PC treatment.

LINC00511 promotes cervical cancer progression by regulating the miR-497-5p/MAPK1 axis.

BACKGROUND: Long non-coding RNA (lncRNA) exhibits a crucial role in multiple human malignancies. The expression of lncRNA LINC00511, reportedly, is aberrantly up-regulated in several types of tumors. Our research was aimed at deciphering the role and mechanism of LINC00511 in the progression of cervical cancer (CC). METHOD: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to quantify the expression levels of LINC00511, miR-497-5p and MAPK1 mRNA in CC tissues and cell lines. Cell counting kit-8 (CCK-8), 5-bromo-2'-deoxyuridine (BrdU) and Transwell assays were conducted for detecting the proliferation, migration and invasion of CC cells. Dual-luciferase reporter gene experiments were performed to verify the targeting relationships amongst LINC00511, miR-497-5p and MAPK1. Besides, MAPK1 expression in CC cells was detected via Western blot after LINC00511 and miR-497-5p were selectively regulated. RESULTS: Up-regulation of LINC00511 expression in CC tissues and cell lines was observed, which was in association with tumor size, clinical stage and lymph node metastasis of the patients. LINC00511 overexpression facilitated the proliferation, migration and invasion of CC cells, while opposite effects were observed after knockdown of LINC00511. Mechanistically, LINC00511 was capable of targeting miR-497-5p and up-regulating MAPK1 expression. CONCLUSION: LINC00511/miR-497-5p/MAPK1 axis regulates CC progression.

CircPDHX promotes prostate cancer cell progression in vitro and tumor growth in vivo via miR-497-5p/ACSL1 axis.

BACKGROUND: Circular RNAs (circRNAs) have been proved could regulate many cancers, including prostate cancer (PCa). In this paper, we reconnoitered the roles of circRNA pyruvate dehydrogenase complex component X (circPDHX) in PCa. METHODS: The circPDHX, microRNA (miR)-497-5p and acyl-CoA synthetase long chain family member 1 (ACSL1) contents were detected by quantitative real-time PCR and Western blot analysis. Cell proliferation was measured by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay, and colony formation assay. Cell migration was examined by wound healing assay. The apoptosis was detected by flow cytometry assay. The ELISA kits were applied to quantify the fatty acid metabolites. Furthermore, the interplay between miR-497-5p and circPDHX or ACSL1 was detected by dual-luciferase reporter assay and RIP assay. The role of circPDHX in PCa was supplementary substantiated in vivo. RESULTS: CircPDHX and ACSL1 contents were upregulated, and the miR-497-5p level was downregulated in PCa. CircPDHX deficiency attenuated PCa cell proliferation, migration, and fatty acid metabolites, while intensified cell apoptosis. CircPDHX bound to miR-497-5p to adjust ACSL1. Moreover, miR-497-5p inhibited the PCa progression by regulating ACSL1. In the meantime, circPDHX deficiency repressed PCa tumor growth in vivo. CONCLUSION: CircPDHX stimulated PCa development via miR-497-5p/ACSL1, which presented a new thought for PCa treatment.

Circ-GGA3 promotes the biological functions of human lens epithelial cells depending on the regulation of miR-497-5p/SMAD4 axis.

The cause of posterior capsular opacification (PCO) is the dysfunction of lens epithelial cells (LECs). Circular RNA (circRNA) was found to regulate cell biological functions, including LECs. However, the role of circ-GGA3 in PCO formation is unclear. Quantitative real-time PCR was used to measure the expression of circ-GGA3, miR-497-5p and SMAD4. Cell proliferation, invasion and migration were determined via MTT assay, EdU staining, transwell assay and wound healing assay. The protein expression of epithelial-mesenchymal transition (EMT) markers, fibrosis markers, TGF-ß/SMAD pathway markers and SMAD4 were determined by western blot assay. The interaction between miR-497-5p and circ-GGA3 or SMAD4 was confirmed using dual-luciferase reporter assay. Circ-GGA3 was highly expressed in PCO patients, and its silencing inhibited the proliferation, invasion, migration, EMT process and fibrosis of TGF-ß2-induced LECs. Circ-GGA3 could sponge miR-497-5p to regulate SMAD4. Further experiments revealed that miR-497-5p inhibitor recovered the negative regulation of circ-GGA3 knockdown on the biological functions of TGF-ß2-induced LECs, and SMAD4 overexpression also abolished the suppressive effect of miR-497-5p. In addition, circ-GGA3/miR-497-5p/SMAD4 axis could activate the TGF-ß/SMAD pathway. Our results indicated that circ-GGA3 could enhance the biological functions of LECs, suggesting that circ-GGA3 might be a potential target for PCO therapy.

Mesenchymal stem cells-derived exosomes prevent sepsis-induced myocardial injury by a CircRTN4/miR-497-5p/MG53 pathway.

Sepsis is a life-threatening organ function dysfunction featured by stimulated oxidative stress and inflammatory responses, in which about 40%-60% of sepsis patients are accompanied with cardiac dysfunction. Mesenchymal stem cells (MSCs)-derived exosomes exert critical roles in the treatment of multiple diseases through transferring non-coding RNAs. Circular RNA (circRNA) is a novel form of functional RNAs that involves in the progression of multiple cardiac pathological condition. Nevertheless, the function of MSCs-derived exosomal circRTN4 in sepsis-induced myocardial injury is still obscure. Significantly, FISH assay demonstrated the location of circRTN4 in cytoplasm of cardiomyocytes. The expression of circRTN4 was reduced in the cardiac tissues from caecal ligation and puncture (CLP) rats and LPS-treated cardiomyocytes. CircRTN4 could be delivered to cardiomyocytes cells via MSCs-derived exosomes. The cardiac injury and apoptosis were induced in the CLP rats and the treatment of MSCs-derived exosomal circRTN4 relieved the phenotypes. MSCs-derived exosomal circRTN4 notably suppressed the upregulated ROS level in the CLP rats. The activity of SOD and GSH was repressed in CLP rats, in which MSCs-derived exosomal circRTN4 rescued the activity in the rats. The upregulated IL-1ß, IL-6, and TNF-α levels in CLP rats were reduced by the treatment of MSCs-derived exosomal circRTN4. MSCs-derived exosomal circRTN4 improved cell survival and suppressed apoptosis of LPS-treated cardiomyocytes. CircRTN4 direct interact with miR-497-5p to upregulate MG53 expression in cardiomyocytes. MSCs-derived exosomal circRTN4 relieves LPS-stimulated cardiomyocyte damage via targeting miR-497-5p/MG53 axis. Therefore, we determine that MSCs-derived exosomes prevent sepsis-induced myocardial injury by a circRTN4/miR-497-5p/MG53 pathway. Our data provides novel insight into the regulatory mechanism by which MSCs-derived exosomal circRTN4 regulates sepsis-induced myocardial injury. MSCs-derived exosomal circRTN4 may be applied as a promising therapeutic approach for sepsis-induced myocardial injury.

Exosome-liposome hybrid nanoparticle codelivery of TP and miR497 conspicuously overcomes chemoresistant ovarian cancer.

BACKGROUND: Although cisplatin-based chemotherapy has been used as the first-line treatment for ovarian cancer (OC), tumor cells develop resistance to cisplatin during treatment, causing poor prognosis in OC patients. Studies have demonstrated that overactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is involved in tumor chemoresistance and that overexpression of microRNA-497 (miR497) may overcome OC chemotherapy resistance by inhibiting the mTOR pathway. However, the low transcriptional efficiency and unstable chemical properties of miR497 limit its clinical application. Additionally, triptolide (TP) was confirmed to possess a superior killing effect on cisplatin-resistant cell lines, partially through inhibiting the mTOR pathway. Even so, the clinical applications of TP are restricted by serious systemic toxicity and weak water solubility. RESULTS: Herein, whether the combined application of miR497 and TP could further overcome OC chemoresistance by synergically suppressing the mTOR signaling pathway was investigated. Bioinspired hybrid nanoparticles formed by the fusion of CD47-expressing tumor exosomes and cRGD-modified liposomes (miR497/TP-HENPs) were prepared to codeliver miR497 and TP. In vitro results indicated that the nanoparticles were efficiently taken up by tumor cells, thus significantly enhancing tumor cell apoptosis. Similarly, the hybrid nanoparticles were effectively enriched in the tumor areas and exerted significant anticancer activity without any negative effects in vivo. Mechanistically, they promoted dephosphorylation of the overactivated PI3K/AKT/mTOR signaling pathway, boosted reactive oxygen species (ROS) generation and upregulated the polarization of macrophages from M2 to M1 macrophages. CONCLUSION: Overall, our findings may provide a translational strategy to overcome cisplatin-resistant OC and offer a potential solution for the treatment of other cisplatin-resistant tumors.

Association of B-cell lymphoma 2/microRNA-497 gene expression ratio score with metastasis in patients with colorectal cancer: A propensity-matched cohort analysis.

BACKGROUND: Deregulated microRNAs (miRs) significantly impact cancer development and progression. Our in silico analysis revealed that miR-497 and its target gene B-cell lymphoma-2 (BCL2) could be related to poor cancer outcomes. PURPOSE: To investigate the BCL2/miRNA-497 expression ratio in colorectal cancer (CRC) and explore its association with the clinicopathological characteristics and CRC prognosis. METHODS: Archived samples from 106 CRC patients were enrolled. MiR-497 and BCL2 gene expressions were detected by Taq-Man Real-Time quantitative polymerase chain reaction in propensity-matched metastatic and nonmetastatic cohorts after elimination of confounder bias. RESULTS: B-cell lymphoma-2 gene was upregulated in metastatic samples (median = 1.16, 95%CI = 1.09-1.60) compared to nonmetastatic (median = 1.02, 95%CI = 0.89-1.25, p < 0.001). In contrast, lower levels of miR-495 were detected in specimens with distant metastasis (median = 0.05, 95%CI = 0.04-0.20) than nonmetastatic samples (median = 0.54, 95%CI = 0.47-0.58, p < 0.001). Estimated BCL2/miR-497 ratio yielded a significant differential expression between the two cohort groups. Higher scores were observed in metastasis group (median = 1.39, 95%CI = 0.9-1.51) than nonmetastatic patients (median = 0.29, 95%CI = 0.19-0.39, p < 0.001). Receiver operating characteristic curve analysis showed BCL2/miR-497 ratio score to have the highest predictive accuracy for metastasis at presentation. The area under the curve was 0.90 (95%CI = 0.839-0.964, p < 0.001) at cut-off of >0.525, with high sensitivity 81.1% (95%CI = 68.6%-89.4%) and specificity 92.5% (95%CI = 82.1%-97.0%). Also, the ratio score was negatively correlated with disease-free survival (r = -0.676, p < 0.001) and overall survival times (r = -0.650, p < 0.001). Kaplan-Meier curves showed lower survival rates in cohorts with high-score compared to low-score patients. CONCLUSION: The BCL2/miR497 expression ratio is associated with poor CRC prognosis in terms of metastasis and short survival.

miRNA Let-7a-5p targets RNA KCNQ1OT1 and Participates in Osteoblast Differentiation to Improve the Development of Osteoporosis.

It is known that miRNA mediates the formation of osteogenesis, but the mechanism by which miRNA let-7a-5p regulates osteogenesis in osteoporosis (OP) is not yet understood. This paper aims to probe into the regulatory mechanism of miRNA let-7a-5p in the development of OP. Fresh femoral trabecular bones of patients with osteoporotic fracture (OP group, n = 25) and non-OP osteoarthritis (Non-OP group, n = 23) who underwent hip replacement in our hospital from December 2016 to December 2019 were collected. The expression and protein levels of miRNA let-7a-5p and V-AKT murine thymoma viral oncogene homolog 3 (RNA KCNQ1OT1) were detected. C2C12 cells were purchased and osteogenic differentiation model was constructed by BMP2 induction. After miRNA let-7a-5p up-regulation or down-regulation by transfection of corresponding mimics and inhibitors, the impacts of miRNA let-7a-5p and RNA KCNQ1OT1 on osteogenic differentiation-related factors (OC, ALP, COL1A1) in C2C12 cells were analyzed. The determination of targeting correlation of miRNA let-7a-5p with RNA KCNQ1OT1 was performed by dual-luciferase reporter (DLR). In OP samples, miRNA let-7a-5p was notably declined while RNA KCNQ1OT1 were remarkably up-regulated. MiRNA let-7a-5p reduced in C2C12 cells as BMP2 treatment proceeded. MiRNA let-7a-5p up-regulation or RNA KCNQ1OT1 down-regulation increased OC, ALP, COL1A1 levels and ALP activity. RNA KCNQ1OT1 was directly targeted to miR-497-5p. RNA KCNQ1OT1 up-regulation weakened the promoting effect of miRNA let-7a-5p up-regulation on osteoblast differentiation. MiRNA let-7a-5p up-regulation can target to reduce RNA KCNQ1OT1 and promote osteoblast differentiation, thereby improving the development of osteoporosis.