miR-200-3p suppresses cell proliferation and reduces apoptosis in diabetic retinopathy via blocking the TGF-β2/Smad pathway

Restoration of miR-200 expression suppresses proliferation and mobility of pancreatic cancer cell

A number of various human malignancies have been associated with abnormal microRNAs (miRNA) expression. There are evidence that miR-200 operates as both tumor suppressor and an onco-miR in a variety of tumors. In this study, we evaluated the effects of miR-200 on the proliferation and migration of pancreatic cancer cells, as well as the underlying molecular pathways. Clinical tissue samples were used to investigate the expression of miR-200 in pancreatic cancer and normal tissues, and the gene expression omnibus (GEO) database provided bioinformatics confirmation. Using the pCMV vector, miR-200 was transfected into PANC-1 pancreatic cancer cells. After transfection, expression of cancer-related genes (at the mRNA and protein levels) was evaluated. The miR-200-transfected pancreatic cancer cells' survival, invasion, migration, and apoptosis were also investigated. According to the bioinformatics analysis, decreased miR-200 expression was associated with a worse prognosis in pancreatic cancer patients. Moreover, low levels of miR-200 in pancreatic cancer tissues were approved. After transfection, pancreatic cancer cells exhibit a sustained increase in expression of miR-200, which inhibits cell viability, invasion, and migration. Additional investigations revealed that increasing expression of miR-200 increases the proportion of pancreatic cancer cells that endure apoptosis. Changes in the mRNA and protein expression of apoptosis- and metastasis-related genes may account for these findings. Our results indicate that miR-200 functions as a tumor suppressor in pancreatic cancer cells and that upregulating miR-200 levels may be a useful therapeutic strategy for pancreatic cancer patients to halt the progression of the illness.

MiR-200a-3p Attenuates Neuropathic Pain by Suppressing the Bromodomain-Containing Protein 3-Nuclear Factor-κB Pathway

MicroRNAs (miRNAs) have key roles in the pathological processes of neuropathic pain. Here, our aim was to elucidate the function of miR-200a-3p as well as its related regulatory mechanism in neuropathic pain. An animal model of neuropathic pain was established by chronic constriction injury (CCI) induction. The knockdown experiments are performed by injecting a lentiviral construct intrathecally. MiR-200a-3p and bromodomain-containing protein 3 (BRD3) expression in rat spinal cord was determined using RT-qPCR. The mechanical, thermal, and cold responses in animals were assessed at the indicated time after surgery. The levels of inflammatory cytokines in rat spinal cord were measured by ELISA. The changes in NF-κB signaling-related molecules in rat spinal cord were determined using western blot and immunofluorescence. MiR-200a-3p was underexpressed in CCI rats in a time-dependent manner. Overexpression of miR-200a-3p decreased mechanical hyperalgesia and thermal sensitivity to attenuate neuropathic pain in rats. BRD3 was targeted by miR-200a-3p. Additionally, downregulation of BRD3 inhibited neuropathic pain progression. Moreover, overexpression of BRD3 rescued the effect of miR-200a-3p on NF-κB signaling and neuropathic pain in CCI rats. MiR-200a-3p attenuates neuropathic pain via downregulating BRD3 to block NF-κB signaling.

Mir-509-3p targets SLC25A13 to regulate ferroptosis and protect retinal endothelial cells in diabetic retinopathy

AIMS

Diabetic retinopathy (DR) is a major complication of diabetes that leads to vision impairment. The aim of this study was to investigate the regulatory role of miR-509-3p in DR, focusing on its interaction with SLC25A13 and its impact on retinal endothelial cell function, oxidative stress, apoptosis, and ferroptosis.

METHODS

HRVECs were cultured in high-glucose (HG) conditions to establish an in vitro DR model. miR-509-3p mimics and inhibitors were transfected into HRVECs to assess their effects on SLC25A13 expression, cell viability, apoptosis, reactive oxygen species (ROS) levels, and ferroptosis markers. A luciferase reporter assay and RNA immunoprecipitation were used to confirm the binding of miR-509-3p to SLC25A13 mRNA. For in vivo validation, agomiR-509-3p was injected into the vitreous of DR mice, and retinal thickness, pathological damage, and apoptosis were evaluated. Ferroptosis-related markers (GPX4, TlR4, ASCL4) were analyzed in HRVECs to explore the mechanism of miR-509-3p in regulating ferroptosis.

RESULTS

In vitro, miR-509-3p significantly decreased SLC25A13 expression, resulting in enhanced HRVEC viability, reduced apoptosis, and lower ROS levels under HG conditions. Overexpression of SLC25A13 reversed these protective effects, while miR-509-3p knockdown exacerbated oxidative stress and apoptosis. In vivo, agomiR-509-3p increased retinal thickness, reduced pathological damage, and decreased apoptosis in DR mice. Ferroptosis marker analysis revealed that miR-509-3p upregulated GPX4 expression and downregulated TlR4 and ASCL4, whereas SLC25A13 overexpression reversed these effects, further linking miR-509-3p to the regulation of ferroptosis.

CONCLUSIONS

miR-509-3p exerts a protective effect in DR by targeting SLC25A13, reducing oxidative stress, apoptosis, and ferroptosis in retinal endothelial cells. These findings highlight the potential of miR-509-3p as a therapeutic target for DR management.

Mechanistic and therapeutic perspectives of non-coding RNA-modulated apoptotic signaling in diabetic retinopathy

Diabetic retinopathy (DR), a significant and vision-endangering complication associated with diabetes mellitus, constitutes a substantial portion of acquired instances of preventable blindness. The progression of DR appears to prominently feature the loss of retinal cells, encompassing neural retinal cells, pericytes, and endothelial cells. Therefore, mitigating the apoptosis of retinal cells in DR could potentially enhance the therapeutic approach for managing the condition by suppressing retinal vascular leakage. Recent advancements have highlighted the crucial regulatory roles played by non-coding RNAs (ncRNAs) in diverse biological processes. Recent advancements have highlighted that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), act as central regulators in a wide array of biogenesis and biological functions, exerting control over gene expression associated with histogenesis and cellular differentiation within ocular tissues. Abnormal expression and activity of ncRNAs has been linked to the regulation of diverse cellular functions such as apoptosis, and proliferation. This implies a potential involvement of ncRNAs in the development of DR. Notably, ncRNAs and apoptosis exhibit reciprocal regulatory interactions, jointly influencing the destiny of retinal cells. Consequently, a thorough investigation into the complex relationship between apoptosis and ncRNAs is crucial for developing effective therapeutic and preventative strategies for DR. This review provides a fundamental comprehension of the apoptotic signaling pathways associated with DR. It then delves into the mutual relationship between apoptosis and ncRNAs in the context of DR pathogenesis. This study advances our understanding of the pathophysiology of DR and paves the way for the development of novel therapeutic strategies.

GLI family zinc finger protein 2 promotes skin fibroblast proliferation and DNA damage repair by targeting the miR-200/ataxia telangiectasia mutated axis in diabetic wound healing

Diabetic foot ulcer (DFU) is a serious complication of diabetic patients which negatively affects their foot health. This study aimed to estimate the role and mechanism of the miR-200 family in DNA damage of diabetic wound healing. Human foreskin fibroblasts (HFF-1 cells) were stimulated with high glucose (HG). Db/db mice were utilized to conduct the DFU in vivo model. Cell viability was evaluated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assays. Superoxide dismutase activity was determined using detection kits. Reactive oxygen species determination was conducted via dichlorodihydrofluorescein-diacetate assays. Enzyme-linked immunosorbent assay was used to evaluate 8-oxo-7,8-dihydro-2'deoxyguanosine levels. Genes and protein expression were analyzed by quantitative real-time polymerase chain reaction, western blotting, or immunohistochemical analyses. Luciferase reporter gene and RNA immunoprecipitation assays determined the interaction with miR-200a/b/c-3p and GLI family zinc finger protein 2 (GLI2) or ataxia telangiectasia mutated (ATM) kinase. HG repressed cell proliferation and DNA damage repair, promoted miR-200a/b/c-3p expression, and suppressed ATM and GLI2. MiR-200a/b/c-3p inhibition ameliorated HG-induced cell proliferation and DNA damage repair repression. MiR-200a/b/c-3p targeted ATM. Then, the silenced ATM reversed the miR-200a/b/c-3p inhibition-mediated alleviative effects under HG. Next, GLI2 overexpression alleviated the HG-induced cell proliferation and DNA damage repair inhibition via miR-200a/b/c-3p. MiR-200a/b/c-3p inhibition significantly promoted DNA damage repair and wound healing in DFU mice. GLI2 promoted cell proliferation and DNA damage repair by regulating the miR-200/ATM axis to enhance diabetic wound healing in DFU.

TGF-β Signaling Pathways in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR), a prevalent complication of diabetes mellitus affecting a significant portion of the global population, has long been viewed primarily as a microvascular disorder. However, emerging evidence suggests that it should be redefined as a neurovascular disease with multifaceted pathogenesis rooted in oxidative stress and advanced glycation end products. The transforming growth factor-β (TGF-β) signaling family has emerged as a major contributor to DR pathogenesis due to its pivotal role in retinal vascular homeostasis, endothelial cell barrier function, and pericyte differentiation. However, the precise roles of TGF-β signaling in DR remain incompletely understood, with conflicting reports on its impact in different stages of the disease. Additionally, the BMP subfamily within the TGF-β superfamily introduces further complexity, with BMPs exhibiting both pro- and anti-angiogenic properties. Furthermore, TGF-β signaling extends beyond the vascular realm, encompassing immune regulation, neuronal survival, and maintenance. The intricate interactions between TGF-β and reactive oxygen species (ROS), non-coding RNAs, and inflammatory mediators have been implicated in the pathogenesis of DR. This review delves into the complex web of signaling pathways orchestrated by the TGF-β superfamily and their involvement in DR. A comprehensive understanding of these pathways may hold the key to developing targeted therapies to halt or mitigate the progression of DR and its devastating consequences.

Classical and Innovative Evidence for Therapeutic Strategies in Retinal Dysfunctions

The human retina is a complex anatomical structure that has no regenerative capacity. The pathogenesis of most retinopathies can be attributed to inflammation, with the activation of the inflammasome protein platform, and to the impact of oxidative stress on the regulation of apoptosis and autophagy/mitophagy in retinal cells. In recent years, new therapeutic approaches to treat retinopathies have been investigated. Experimental data suggest that the secretome of mesenchymal cells could reduce oxidative stress, autophagy, and the apoptosis of retinal cells, and in turn, the secretome of the latter could induce changes in mesenchymal cells. Other studies have evidenced that noncoding (nc)RNAs might be new targets for retinopathy treatment and novel disease biomarkers since a correlation has been found between ncRNA levels and retinopathies. A new field to explore is the interaction observed between the ocular and intestinal microbiota; indeed, recent findings have shown that the alteration of gut microbiota seems to be linked to ocular diseases, suggesting a gut-eye axis. To explore new therapeutical strategies for retinopathies, it is important to use proper models that can mimic the complexity of the retina. In this context, retinal organoids represent a good model for the study of the pathophysiology of the retina.

miR-200a-3p overexpression alleviates diabetic cardiomyopathy injury in mice by regulating autophagy through the FOXO3/Mst1/Sirt3/AMPK axis

Objective

Hyperglycemia and insulin resistance or deficiency are characteristic features of diabetes. Diabetes is accompanied by cardiomyocyte hypertrophy, fibrosis and ventricular remodeling, and eventually heart failure. In this study, we established a diabetic cardiomyopathy (DCM) mouse model to explore the role and mechanism of miR-200a-3p in DCM.

Methods

We used db/db mice to simulate the animal model of DCM and the expression of miR-200a-3p was then examined by RT-qPCR. Tail vein injection of mice was done with rAAV-miR-200a-3p for 8 weeks, and cardiac function was assessed by cardiac ultrasound. The levels of myocardial tissue injury, fibrosis, inflammation, apoptosis and autophagy in mice were detected by histological staining, TUNEL and other molecular biological experiments.

Results

miR-200a-3p expression levels were significantly decreased in the myocardium of DCM mice. Diabetic mice developed cardiac dysfunction and presented pathological changes such as myocardial injury, myocardial interstitial fibrosis, cardiomyocyte apoptosis, autophagy, and inflammation. Overexpression of miR-200a-3p expression significantly ameliorated diabetes induced-cardiac dysfunction and myocardial injury, myocardial interstitial fibrosis, cardiomyocyte apoptosis, and inflammation, and enhanced autophagy. Mechanistically, miR-200a-3p interacted with FOXO3 to promote Mst1 expression and reduce Sirt3 and p-AMPK expression.

Conclusion

In type 2 diabetes, increased miR-200a-3p expression enhanced autophagy and participated in the pathogenic process of cardiomyopathy throug7 Mst1/Sirt3/AMPK axis regulation by its target gene FOXO3. This conclusion provides clues for the search of new gene targeted therapeutic approaches for diabetic cardiomyopathy.

The Role of miR-29 Family in TGF-β Driven Fibrosis in Glaucomatous Optic Neuropathy

Primary open angle glaucoma (POAG), a chronic optic neuropathy, remains the leading cause of irreversible blindness worldwide. It is driven in part by the pro-fibrotic cytokine transforming growth factor beta (TGF-β) and leads to extracellular matrix remodelling at the lamina cribrosa of the optic nerve head. Despite an array of medical and surgical treatments targeting the only known modifiable risk factor, raised intraocular pressure, many patients still progress and develop significant visual field loss and eventual blindness. The search for alternative treatment strategies targeting the underlying fibrotic transformation in the optic nerve head and trabecular meshwork in glaucoma is ongoing. MicroRNAs are small non-coding RNAs known to regulate post-transcriptional gene expression. Extensive research has been undertaken to uncover the complex role of miRNAs in gene expression and miRNA dysregulation in fibrotic disease. MiR-29 is a family of miRNAs which are strongly anti-fibrotic in their effects on the TGF-β signalling pathway and the regulation of extracellular matrix production and deposition. In this review, we discuss the anti-fibrotic effects of miR-29 and the role of miR-29 in ocular pathology and in the development of glaucomatous optic neuropathy. A better understanding of the role of miR-29 in POAG may aid in developing diagnostic and therapeutic strategies in glaucoma.

BMP2 as a promising anticancer approach: functions and molecular mechanisms

Bone morphogenetic protein 2 (BMP2), a pluripotent factor, is a member of the transforming growth factor-beta (TGF-β) superfamily and is implicated in embryonic development and postnatal homeostasis in tissues and organs. Experimental research in the contexts of physiology and pathology has indicated that BMP2 can induce macrophages to differentiate into osteoclasts and accelerate the osteolytic mechanism, aggravating cancer cell bone metastasis. Emerging studies have stressed the potent regulatory effect of BMP2 in cancer cell differentiation, proliferation, survival, and apoptosis. Complicated signaling networks involving multiple regulatory proteins imply the significant biological functions of BMP2 in cancer. In this review, we comprehensively summarized and discussed the current evidence related to the modulation of BMP2 in tumorigenesis and development, including evidence related to the roles and molecular mechanisms of BMP2 in regulating cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), cancer angiogenesis and the tumor microenvironment (TME). All these findings suggest that BMP2 may be an effective therapeutic target for cancer and a new marker for assessing treatment efficacy.

Effects of the Calix[4]arene Derivative Compound OTX008 on High Glucose-Stimulated ARPE-19 Cells: Focus on Galectin-1/TGF-β/EMT Pathway

Diabetic retinopathy (DR) is a neurovascular disease characterized by the reduction of retina integrity and functionality, as a consequence of retinal pigment epithelial cell fibrosis. Although galectin-1 (a glycan-binding protein) has been associated with dysregulated retinal angiogenesis, no evidence has been reported about galectin-1 roles in DR-induced fibrosis. ARPE-19 cells were cultured in normal (5 mM) or high glucose (35 mM) for 3 days, then exposed to the selective galectin-1 inhibitor OTX008 (2.5–5–10 μM) for 6 days. The determination of cell viability and ROS content along with the analysis of specific proteins (by immunocytochemistry, Western blotting, and ELISA) or mRNAs (by real time-PCR) were performed. OTX008 5 μM and 10 μM improved cell viability and markedly reduced galectin-1 protein expression in cells exposed to high glucose. This was paralleled by a down-regulation of the TGF-β/, NF-kB p65 levels, and ROS content. Moreover, epithelial–mesenchymal transition markers were reduced by OTX008 5 μM and 10 μM. The inhibition of galectin-1 by OTX008 in DR may preserve retinal pigment epithelial cell integrity and functionality by reducing their pro-fibrotic phenotype and epithelial–mesenchymal transition phenomenon induced by diabetes.

Recent Advances in KEAP1/NRF2-Targeting Strategies by Phytochemical Antioxidants, Nanoparticles, and Biocompatible Scaffolds for the Treatment of Diabetic Cardiovascular Complications

Significance: Modulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated antioxidant response is a key aspect in the onset of diabetes-related cardiovascular complications. With this review, we provide an overview of the recent advances made in the development of Nrf2-targeting strategies for the treatment of diabetes, with particular attention toward the activation of Nrf2 by natural antioxidant compounds, nanoparticles, and oxidative stress-modulating biocompatible scaffolds. Recent Advances: In the past 30 years, studies addressing the use of antioxidant therapies to treat diabetes have grown exponentially, showing promising but yet inconclusive results. Animal studies and clinical trials on the Nrf2 pathway have shown promising results, suggesting that its activation can delay or reverse some of the cardiovascular impairments in diabetes. Critical Issues: Hyperglycemia- and oscillating glucose levels-induced reactive oxygen species (ROS) accumulation is progressively emerging as a central factor in the onset and progression of diabetes-related cardiovascular complications, including endothelial dysfunction, retinopathy, heart failure, stroke, critical limb ischemia, ulcers, and delayed wound healing. In this context, accumulating evidence suggests a central role for Nrf2-mediated antioxidant response, one of the most studied cellular defensive mechanisms against ROS accumulation. Future Directions: Innovative approaches such as tissue engineering and nanotechnology are converging toward targeting oxidative stress in diabetes. Antioxid. Redox Signal. 36, 707-728.

Danhong injection represses diabetic retinopathy and nephropathy advancement in diabetic mice by upregulating microRNA-30d-5p and targeting JAK1

Danhong injection (DHI) restrains diabetic retinopathy and nephropathy (DR and DN) advancement in diabetic mice. However, the downstream mechanism of its modulation is not fully studied. Diabetic model mice (db/db mice) were intravenously injected with DHI and corresponding virus particles. MiR-30d-5p and JAK1 were detected. The body weight and fasting blood glucose mice were measured every 4 weeks. The renal tissues and serum of mice were collected, and the contents of creatinine and blood urea nitrogen were biochemically analyzed. IL-6, IFN-γ and TNF-α were detected by ELISA, with the pathological conditions of renal tissues in mice by He staining, and the adjustment conditions by TUNEL. Human retinal pigment epithelium (ARPE-19) cells were selected to induce DR model in vitro by high glucose, and exposed to DHI for treatment. The corresponding plasmids were transfected, and miR-30d-5p and JAK1 were detected, with the proliferation ability by plate cloning, apoptosis by flow cytometry, and cell migration ability by Transwell. The angiogenesis ability of cells was assessed by tube formation assay. The targeting relationship between miR-30d-5p and JAK1 was detected. The results manifested that miR-30d-5p was declined in DR and DN, while JAK1 expression was elevated. DHI was able to improve DR and renal injury. DHI could regulate the miR-30d-5p-JAK1 axis in vivo, and miR-30d-5p targeted and regulated JAK1. Upregulation of miR-30d-5p or inhibition of JAK1 could improve DR and renal injury. The results implies that DHI can repress the development of DR and DN by elevating miR-30d-5p and targeting JAK1.

Research progress on exosomes/microRNAs in the treatment of diabetic retinopathy

Diabetic retinopathy (DR) is the leakage and obstruction of retinal microvessels caused by chronic progressive diabetes that leads to a series of fundus lesions. If not treated or controlled, it will affect vision and even cause blindness. DR is caused by a variety of factors, and its pathogenesis is complex. Pericyte-related diseases are considered to be an important factor for DR in many pathogeneses, which can lead to DR development through direct or indirect mechanisms, but the specific mechanism remains unclear. Exosomes are small vesicles of 40-100 nm. Most cells can produce exosomes. They mediate intercellular communication by transporting microRNAs (miRNAs), proteins, mRNAs, DNA, or lipids to target cells. In humans, intermittent hypoxia has been reported to alter circulating excretory carriers, increase endothelial cell permeability, and promote dysfunction in vivo. Therefore, we believe that the changes in circulating exocrine secretion caused by hypoxia in DR may be involved in its progress. This article examines the possible roles of miRNAs, proteins, and DNA in DR occurrence and development and discusses their possible mechanisms and therapy. This may help to provide basic proof for the use of exocrine hormones to cure DR.

miR-200a-3p improves neonatal necrotizing enterocolitis by regulating RIPK1

BACKGROUND

Necrotizing enterocolitis (NEC) is an acquired disease, which mainly occurs in premature infants or sick newborns. microRNA (miR), as a common non-coding RNA in recent years, is found in many diseases. In this research, miR usefulin NEC is analyzed by GEO.

METHOD

The differentially expressed miRs in NEC were screened by analyzing GSE68054, and miR-200a-3p in IEC-6 cells induced by lipopolysaccharide (LPS) and serum of NEC children were detected by qRT-PCR. The role of miR-200a-3p in LPS-induced IEC-6 cells was tested using CCK-8, PI dyeing, and inflammatory cytokine detection. The direct downstream molecules of miR-200a-3p were identified using TargetScanHuman and verified by luciferase reporter gene assay. The mechanism of action was explored using western blot.

RESULTS

miR-200a-3p in IEC-6 treated with NEC and LPS was significantly decreased. In vitro experiments revealed that miR-200a-3p mimetic could inhibit IL-6 and TNF-α in IEC-6 cells induced by LPS and reduce the positive rate of PI. In addition, it was determined that receptor-interacting protein kinase 1 (RIPK1) was a downstream molecule of miR-200a-3p, and overexpression of RIPK1 could aggravate LPS-induced IEC-6 injury, while miR-200a-3p mimics could alleviate the overexpression of RIPK1. miR-200a-3p mimics inhibited the elevation of necrosis-related molecules and the interaction between RIPK1 and RIPK3 in LPS-induced IEC-6 cells.

CONCLUSION

miR-200a-3p can protect intestinal epithelial cells from LPS injury by inhibiting inflammation and necrosis mediated by RIPK1, which provides a possible target for NEC.

Circ_001209 aggravates diabetic retinal vascular dysfunction through regulating miR-15b-5p/COL12A1

OBJECTIVE

Diabetic retinopathy, a common complication of diabetes mellitus and a major cause of blindness. circRNAs spongs target miRNA and thus influencing mRNA expression in DR. We investigated the mechanism of circ_001209 in regulating diabetic retinal vascular dysfunction.

METHODS

QRT-PCR analysis was performed to detect the expression of miR-15b-5p, COL12A1 and circ_001209 in human retinal vascular endothelial cells (HRVECs) under high glucose conditions. Western blot assay, wound healing assay, transwell assay and tube formation were used to explore the roles of circ_001209/miR-15b-5p/COL12A1 in retinal vascular dysfunction. Bioinformatics analysis and luciferase reporter, RNA-FISH, and overexpression assays were performed to reveal the mechanisms of the circ_001209/miR-15b-5p/COL12A1 interaction. TUNEL staining and H&E staining were used to evaluate the pathological changes in streptozotocin (STZ)-induced DR in rats.

RESULTS

Downregulation of miR-15b-5p under HG conditions promoted proliferation, migration, and tube formation of HRVECs. QRT-PCR and western blot results revealed that miR-15b-5p affected the HRVECs function through targeting COL12A1. Under HG conditions, circ_001209, which acts as a sponge of miR-15b-5p, is upregulated. Besides, overexpression of circ_001209 can affect HRVEC function and aggravate retinal injury in diabetic rats.

CONCLUSION

Upregulation of circ_001209 contributes to vascular dysfunction in diabetic retinas through regulating miR-15b-5p and COL12A1, providing a potential treatment strategy for diabetic retinopathy.

Circ_0084043 Facilitates High Glucose-Induced Retinal Pigment Epithelial Cell Injury by Activating miR-128-3p/TXNIP-Mediated Wnt/β-Catenin Signaling Pathway

ABSTRACT

Diabetic retinopathy is a frequent complication of diabetes mellitus and one of the common causes of blindness. Circular RNAs (circRNAs) can modulate various biological behaviors of human diseases. Circ_0084043 is a novel circRNA, and its function in diabetic retinopathy progression is unclear. Adult retinal pigment epithelial cells (ARPE-19) were treated with high glucose (HG). RNA levels of circ_0084043, microRNA-128-3p (miR-128-3p), and thioredoxin-interacting protein (TXNIP) were detected by quantitative real-time polymerase chain reaction. 3-(4, 5-dimethylthiazole-2-y1)-2, 5-diphenyl tetrazolium bromide and flow cytometry were, respectively, used to examine cell viability and apoptosis. Apoptotic and TNXIP relative protein levels were measured by Western blot. The combination between targets was analyzed through dual-luciferase reporter assay or RNA immunoprecipitation assay. Results showed that HG induced the upregulation of circ_0084043 and the downregulation of miR-128-3p in ARPE-19 cells. Circ_0084043 knockdown or miR-128-3p overexpression mitigated the HG-mediated cell viability inhibition, apoptosis promotion, and inflammatory response. Circ_0084043 targeted miR-128-3p and miR-128-3p inhibitor returned the regulation of si-circ_0084043 in HG-treated cells. TXNIP was the target gene of miR-128-3p and TXNIP overexpression abolished the miR-128-3p-mediated effects after HG treatment. Circ_0084043 regulated the TXNIP expression to activate Wnt/β-catenin signal pathway by targeting miR-128-3p. Our findings unraveled that circ_0084043 promoted the HG-induced retinal pigment epithelial cell injury through activating the Wnt/β-catenin signal pathway by the miR-128-3p/TXNIP axis. Circ_0084043 might be an available biomarker in diabetic retinopathy diagnosis and therapy.

miRNA, lncRNA and circRNA: Targeted Molecules Full of Therapeutic Prospects in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR) is a common diabetic complication and the main cause of blindness worldwide, which seriously affects the quality of life of patients. Studies have shown that noncoding RNA (ncRNA) has distinct differentiated expression in DR and plays an important role in the occurrence and development of DR. ncRNAs represented by microRNAs (miRNAs), lncRNAs (lncRNAs), and circRNAs (circRNAs) have been shown to be widely involved in the regulation of gene expression and affect multiple biological processes of retinopathy. This article will review three RNAs related to the occurrence and development of DR on the basis of previous studies (especially their effects on retinal microangiopathy, retinal pigment epithelial cells, and retinal nerve cells) and discuss their underlying mechanisms and connections. Overall, this review will help us better understand the role of ncRNAs in the occurrence and development of DR and provide ideas for exploring potential therapeutic directions and targets.