Long Non-coding RNA GAS5 Maintains Insulin Secretion by Regulating Multiple miRNAs in INS-1 832/13 Cells

NPC86 Increases LncRNA Gas5 In Vivo to Improve Insulin Sensitivity and Metabolic Function in Diet-Induced Obese Diabetic Mouse Model

In the United States, an estimated 38 million individuals (10% of the population) have type 2 diabetes mellitus (T2D), while approximately 97.6 million adults (38%) have prediabetes. Long noncoding RNAs (lncRNAs) are critical regulators of gene expression and metabolism. We were the first to demonstrate that lncRNA Growth Arrest-Specific Transcript 5 (GAS5 (human)/gas5 (mouse)) is decreased in the serum of T2D patients and established GAS5 as a biomarker for T2D diagnosis and onset prediction, now validated by other groups. We further demonstrated that GAS5 depletion impaired glucose uptake, decreased insulin receptor levels, and inhibited insulin signaling in human adipocytes, highlighting its potential as a therapeutic target in T2D. To address this, we developed NPC86, a small-molecule compound that stabilizes GAS5 by disrupting its interaction with UPF-1, an RNA helicase involved in nonsense-mediated decay (NMD) that regulates RNA stability. NPC86 increased GAS5 and insulin receptor (IR) levels, enhanced insulin signaling, and improved glucose uptake in vitro. In this study, we tested the efficacy of NPC86 in vivo in a diet-induced obese diabetic (DIOD) mouse model, and NPC86 treatment elevated gas5 levels, improved glucose tolerance, and enhanced insulin sensitivity, with no observed toxicity or weight changes. A transcriptomics analysis of adipose tissue revealed the upregulation of insulin signaling and metabolic pathways, including oxidative phosphorylation and glycolysis, while inflammatory pathways were downregulated. These findings highlight NPC86's therapeutic potential in T2D.

SNORD80-guided 2'-O-methylation stabilizes the lncRNA GAS5 to regulate cellular stress responses

The introns of the gene encoding the long noncoding RNA (lncRNA) GAS5 host up to 10 C/D box small nucleolar RNAs (snoRNAs). However, whether there is a regulatory and functional relationship between these snoRNAs and GAS5 is unknown. Here, we show that the expression of SNORD80, but not the other snoRNAs, parallels GAS5 expression and is regulated alongside GAS5 in response to cellular stress. The 2'-O-methylation at the A496 site, located within a segment of GAS5 complementing the conserved RNA-binding region on SNORD80, promotes GAS5 stability and consequent upregulation. This methylation requires SNORD80, as it is diminished by knockdown of SNORD80 and increased by SNORD80 overexpression, similar to the effects of manipulating the expression of fibrillarin, the methyltransferase of the box C/D small nucleolar ribonucleoprotein particle (snoRNP). The upregulation of SNORD80 in response to cellular stress is due to an enhancement in its stability, which is associated with an increase in its interaction with fibrillarin. Collectively, these results identify a role for SNORD80 in guiding 2'-O-methylation to stabilize GAS5. This uncovers a feedforward regulatory loop at the GAS5 gene locus in response to cellular stress and sheds light on posttranscriptional mechanisms governing lncRNA expression.

FXR-regulated COX6A2 triggers mitochondrial apoptosis of pancreatic β-cell in type 2 diabetes

Pancreatic β-cell apoptosis plays a crucial role in the development of type 2 diabetes. Cytochrome c oxidase subunit 6A2 (COX6A2) and Farnesoid X Receptor (FXR) have been identified in pancreatic β-cells, however, whether they are involved in β-cell apoptosis is unclear. Here, we sought to investigate the role of FXR-regulated COX6A2 in diabetic β-cell apoptosis. We found that COX6A2 expression was increased in islets from diabetic animals, whereas FXR expression was suppressed. Notably, overexpression of COX6A2 facilitated β-cell apoptosis, whereas its deficiency attenuated this process and ameliorates type 2 diabetes, suggesting a pro-apoptotic role of COX6A2 in β-cells. Mechanistically, increased COX6A2 interacted with and enhanced the expression of voltage-dependent anion channel 1 (VDAC1), thereby promoting the mitochondrial translocation of Bax, leading to the release of cytochrome c from the mitochondria to the cytoplasm and ultimately causing β-cell apoptosis. Moreover, FXR negatively regulated COX6A2 expression through the inhibition of histone acetyltransferase p300 occupancy, diminishing histone H3 acetylation at lysine 27 on the Cox6a2 promoter. Furthermore, the deficiency of FXR intensified β-cell apoptosis under diabetic situations. Thus, it is probable that in diabetogenic environments, reduced FXR expression contributes to enhanced COX6A2 expression, culminating in β-cell apoptosis. These findings emphasize the essential involvement of the FXR/p300 pathway-controlled COX6A2 in β-cell apoptosis, revealing a previously undiscovered mechanism underlying diabetic β-cell apoptosis.

Bulk and single-cell transcriptome profiling identify potential cellular targets of the long noncoding RNA Gas5 in renal fibrosis

The long noncoding RNA growth arrest-specific 5 (lncRNA Gas5) is implicated in various kidney diseases. In this study, we investigated the lncRNA Gas5 expression profile and its critical role as a potential biomarker in the progression of chronic kidney disease. Subsequently, we assessed the effect of lncRNA Gas5 deletion on renal fibrosis induced by unilateral ureteral obstruction (UUO). The results indicated that loss of lncRNA Gas5 exacerbates UUO-induced renal injury and extracellular matrix deposition. Notably, the deletion of lncRNA Gas5 had a similar effect on control mice. The fibrogenic phenotype observed in mice lacking lncRNA Gas5 correlates with peroxisome proliferator-activated receptor (PPAR) signaling pathway activation and aberrant cytokine and chemokine reprogramming. Single-cell RNA sequencing analysis revealed key transcriptomic features of fibroblasts after Gas5 deletion, revealing heterogeneous cellular states suggestive of a propensity for renal fibrosis. Our findings indicate that lncRNA Gas5 regulates the differentiation and activation of immune cells and the transcription of key genes in the PPAR signaling pathway. These data offer novel insights into the involvement of lncRNA Gas5 in renal fibrosis, potentially paving the way for innovative diagnostic and therapeutic targets.

GAS5 lncRNA: A biomarker and therapeutic target in breast cancer

Breast cancer is one of the most common causes of cancer-related mortality globally, and its aggressive phenotype results in poor treatment outcomes. Growth Arrest-Specific 5 long non-coding RNA has attracted considerable attention due to its pivotal function in apoptosis regulation and tumor aggressiveness in breast cancer. Gas5 enhances apoptosis by regulating apoptotic proteins, such as caspases and BCL2 family proteins, and the sensitivity of BCCs to chemotherapeutic agents. At the same time, low levels of GAS5 increased invasion, metastasis, and overall tumor aggressiveness. GAS5 also regulates EMT markers, critical for cancer metastasis, and influences tumor cell proliferation by regulating various signaling components. As a result, GAS5 can be restored to suppress tumor development as a possible therapeutic strategy, which might present promising prospects for a patient's treatment. Its activity levels might also be a crucial indicator and diagnostic parameter for prediction. This review highlights the significant role of GAS5 in modulating apoptosis and tumor aggressiveness in breast cancer, emphasizing its potential as a therapeutic target for breast cancer treatment and management.

Targeting β-Cell Plasticity: A Promising Approach for Diabetes Treatment

The β-cells within the pancreas play a pivotal role in insulin production and secretion, responding to fluctuations in blood glucose levels. However, factors like obesity, dietary habits, and prolonged insulin resistance can compromise β-cell function, contributing to the development of Type 2 Diabetes (T2D). A critical aspect of this dysfunction involves β-cell dedifferentiation and transdifferentiation, wherein these cells lose their specialized characteristics and adopt different identities, notably transitioning towards progenitor or other pancreatic cell types like α-cells. This process significantly contributes to β-cell malfunction and the progression of T2D, often surpassing the impact of outright β-cell loss. Alterations in the expressions of specific genes and transcription factors unique to β-cells, along with epigenetic modifications and environmental factors such as inflammation, oxidative stress, and mitochondrial dysfunction, underpin the occurrence of β-cell dedifferentiation and the onset of T2D. Recent research underscores the potential therapeutic value for targeting β-cell dedifferentiation to manage T2D effectively. In this review, we aim to dissect the intricate mechanisms governing β-cell dedifferentiation and explore the therapeutic avenues stemming from these insights.

The role of noncoding RNAs in beta cell biology and tissue engineering

The loss or dysfunction of pancreatic β-cells, which are responsible for insulin secretion, constitutes the foundation of all forms of diabetes, a widely prevalent disease worldwide. The replacement of damaged β-cells with regenerated or transplanted cells derived from stem cells is a promising therapeutic strategy. However, inducing the differentiation of stem cells into fully functional glucose-responsive β-cells in vitro has proven to be challenging. Noncoding RNAs (ncRNAs) have emerged as critical regulatory factors governing the differentiation, identity, and function of β-cells. Furthermore, engineered hydrogel systems, biomaterials, and organ-like structures possess engineering characteristics that can provide a three-dimensional (3D) microenvironment that supports stem cell differentiation. This review summarizes the roles and contributions of ncRNAs in maintaining the differentiation, identity, and function of β-cells. And it focuses on regulating the levels of ncRNAs in stem cells to activate β-cell genetic programs for generating alternative β-cells and discusses how to manipulate ncRNA expression by combining hydrogel systems and other tissue engineering materials. Elucidating the patterns of ncRNA-mediated regulation in β-cell biology and utilizing this knowledge to control stem cell differentiation may offer promising therapeutic strategies for generating functional insulin-producing cells in diabetes cell replacement therapy and tissue engineering.

Repurposing Metformin for periodontal disease management as a form of oral-systemic preventive medicine

BACKGROUND

Despite the improvements in treatment over the last decades, periodontal disease (PD) affects millions of people around the world and the only treatment available is based on controlling microbial load. Diabetes is known to increase the risk of PD establishment and progression, and recently, glucose metabolism modulation by pharmaceutical or dietarian means has been emphasised as a significant modulator of non-communicable disease development.

METHODS

The impact of pharmaceutically controlling glucose metabolism in non-diabetic animals and humans (REBEC, UTN code: U1111-1276-1942) was investigated by repurposing Metformin, as a mean to manage periodontal disease and its associated systemic risk factors.

RESULTS

We found that glucose metabolism control via use of Metformin aimed at PD management resulted in significant prevention of bone loss during induced periodontal disease and age-related bone loss in vivo. Metformin also influenced the bacterial species present in the oral environment and impacted the metabolic epithelial and stromal responses to bacterial dysbiosis at a single cell level. Systemically, Metformin controlled blood glucose levels and age-related weight gain when used long-term. Translationally, our pilot randomized control trial indicated that systemic Metformin was safe to use in non-diabetic patients and affected the periodontal tissues. During the medication window, patients showed stable levels of systemic blood glucose, lower circulating hsCRP and lower insulin levels after periodontal treatment when compared to placebo. Finally, patients treated with Metformin had improved periodontal parameters when compared to placebo treated patients.

CONCLUSION

This is the first study to demonstrate that systemic interventions using Metformin in non-diabetic individuals aimed at PD prevention have oral-systemic effects constituting a possible novel form of preventive medicine for oral-systemic disease management.

Long non-coding RNAs: key regulators of liver and kidney fibrogenesis

Fibrosis is a pathological condition that is characterized by an abnormal buildup of extracellular matrix (ECM) components, such as collagen, in tissues. This condition affects various organs of the body, including the liver and kidney. Early diagnosis and treatment of fibrosis are crucial, as it is a progressive and irreversible process in both organs. While there are certain similarities in the fibrosis process between the liver and kidney, there are also significant differences that must be identified to determine molecular diagnostic markers and potential therapeutic targets. Long non-coding RNAs (lncRNAs), a class of RNA molecules that do not code for proteins, are increasingly recognized as playing significant roles in gene expression regulation. Emerging evidence suggests that specific lncRNAs are involved in fibrosis development and progression by modulating signaling pathways, such as the TGF-β/Smad pathway and the β-catenin pathway. Thus, identifying the precise lncRNAs involved in fibrosis could lead to novel therapeutic approaches for fibrotic diseases. In this review, we summarize lncRNAs related to fibrosis in the liver and kidney, and propose their potential as therapeutic targets based on their functions. [BMB Reports 2023; 56(7): 374-384].

Clinical Significance of MicroRNAs, Long Non-Coding RNAs, and CircRNAs in Cardiovascular Diseases

Based on recent research, the non-coding genome is essential for controlling genes and genetic programming during development, as well as for health and cardiovascular diseases (CVDs). The microRNAs (miRNAs), lncRNAs (long ncRNAs), and circRNAs (circular RNAs) with significant regulatory and structural roles make up approximately 99% of the human genome, which does not contain proteins. Non-coding RNAs (ncRNA) have been discovered to be essential novel regulators of cardiovascular risk factors and cellular processes, making them significant prospects for advanced diagnostics and prognosis evaluation. Cases of CVDs are rising due to limitations in the current therapeutic approach; most of the treatment options are based on the coding transcripts that encode proteins. Recently, various investigations have shown the role of nc-RNA in the early diagnosis and treatment of CVDs. Furthermore, the development of novel diagnoses and treatments based on miRNAs, lncRNAs, and circRNAs could be more helpful in the clinical management of patients with CVDs. CVDs are classified into various types of heart diseases, including cardiac hypertrophy (CH), heart failure (HF), rheumatic heart disease (RHD), acute coronary syndrome (ACS), myocardial infarction (MI), atherosclerosis (AS), myocardial fibrosis (MF), arrhythmia (ARR), and pulmonary arterial hypertension (PAH). Here, we discuss the biological and clinical importance of miRNAs, lncRNAs, and circRNAs and their expression profiles and manipulation of non-coding transcripts in CVDs, which will deliver an in-depth knowledge of the role of ncRNAs in CVDs for progressing new clinical diagnosis and treatment.

Identification and analysis of type 2 diabetes-mellitus-associated autophagy-related genes

Introduction

Autophagy, an innate safeguard mechanism for protecting the organism against harmful agents, is implicated in the survival of pancreatic â cells and the development of type 2 diabetes mellitus (T2DM). Potential autophagy-related genes (ARGs) may serve as potential biomarkers for T2DM treatment.

Methods

The GSE25724 dataset was downloaded from the Gene Expression Omnibus (GEO) database, and ARGs were obtained from the Human Autophagy Database. The differentially expressed autophagy-related genes (DEARGs) were screened at the intersection of ARGs and differentially expressed genes (DEGs) between T2DM and non-diabetic islet samples, which were subjected to functional enrichment analyses. A protein-protein interaction (PPI) network was constructed to identify hub DEARGs. Expressions of top 10 DEARGs were validated in human pancreatic â-cell line NES2Y and rat pancreatic INS-1 cells using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell viability and insulin secretion were measured after cell transfection with lentiviral vector EIF2AK3 or RB1CC1 into islet cells.

Results

In total, we discovered 1,270 DEGs (266 upregulated and 1,004 downregulated genes) and 30 DEARGs enriched in autophagy- and mitophagy-related pathways. In addition, we identified GAPDH, ITPR1, EIF2AK3, FOXO3, HSPA5, RB1CC1, LAMP2, GABARAPL2, RAB7A, and WIPI1 genes as the hub ARGs. Next, qRT-PCR analysis revealed that expressions of hub DEARGs were consistent with findings from bioinformatics analysis. EIF2AK3, GABARAPL2, HSPA5, LAMP2, and RB1CC1 were both differentially expressed in the two cell types. Overexpression of EIF2AK3 or RB1CC1 promoted cell viability of islet cells and increased the insulin secretion.

Discussion

This study provides potential biomarkers as therapeutic targets for T2DM.

lncRNA UCA1 inhibits mitochondrial dysfunction of skeletal muscle in type 2 diabetes mellitus by sequestering miR-143-3p to release FGF21

Increasing evidence suggests that insulin resistance in type 2 diabetes mellitus (T2DM) is associated with mitochondrial dysfunction in skeletal muscle, while the underlying molecular mechanisms remain elusive. This study aims to construct a ceRNA regulatory network that is involved in mitochondrial dysfunction of skeletal muscle in T2DM. Based on GEO database analysis, differentially expressed lncRNA and mRNA profiles were identified in skeletal muscle tissues of T2DM. Next, LASSO regression analysis was conducted to predict the key lncRNAs related to T2DM, which was validated by receiver operating characteristic (ROC) analysis. Moreover, the miRNAs related to skeletal muscle in T2DM were identified by WGCNA, followed by construction of gene-gene interaction network and GO and KEGG enrichment analyses. It was found that 12 lncRNAs and 6 miRNAs were related to skeletal muscle in T2DM. Moreover, the lncRNA-miRNA-mRNA ceRNA network involving UCA1, miR-143-3p, and FGF21 was constructed. UCA1, and FGF21 were downregulated, while miR-143-3p was upregulated in skeletal muscle cells (SkMCs) exposed to palmitic acid. Additionally, ectopic expression experiments were performed in SkMCs to confirm the effects of UCA1/miR-143-3p/FGF21 on mitochondrial dysfunction by determining mitochondrial ROS, oxygen consumption rate (OCR), membrane potential, and ATP level. Overexpression of miR-143-3p increased ROS accumulation and reduced the OCR, fluorescence ratio of JC-1, and ATP level, which were reversed by upregulation of UCA1 or FGF21. Collectively, lncRNA UCA1 inhibited mitochondrial dysfunction of skeletal muscle in T2DM by sequestering miR-143-3p away from FGF21, therefore providing a potential therapeutic target for alleviating mitochondrial dysfunction of skeletal muscle in T2DM.

Long Noncoding RNAs in the Pathogenesis of Insulin Resistance

Insulin resistance (IR), designated as the blunted response of insulin target tissues to physiological level of insulin, plays crucial roles in the development and progression of diabetes, nonalcoholic fatty liver disease (NAFLD) and other diseases. So far, the distinct mechanism(s) of IR still needs further exploration. Long non-coding RNA (lncRNA) is a class of non-protein coding RNA molecules with a length greater than 200 nucleotides. LncRNAs are widely involved in many biological processes including cell differentiation, proliferation, apoptosis and metabolism. More recently, there has been increasing evidence that lncRNAs participated in the pathogenesis of IR, and the dysregulated lncRNA profile played important roles in the pathogenesis of metabolic diseases including obesity, diabetes and NAFLD. For example, the lncRNAs MEG3, H19, MALAT1, GAS5, lncSHGL and several other lncRNAs have been shown to regulate insulin signaling and glucose/lipid metabolism in various tissues. In this review, we briefly introduced the general features of lncRNA and the methods for lncRNA research, and then summarized and discussed the recent advances on the roles and mechanisms of lncRNAs in IR, particularly focused on liver, skeletal muscle and adipose tissues.

H19 is involved in the regulation of inflammatory responses in acute gouty arthritis by targeting miR-2-3p

A great number of studies have confirmed that long noncoding RNA (lncRNA) are involved in the regulation of inflammatory response in acute gouty arthritis (AGA). This paper aimed to survey the regulatory mechanism of H19 on AGA. The expression of serum H19 in all subjects was examined by qRT-PCR. The ROC curve was used to estimate the diagnostic value of H19 for AGA. THP-1 cells were induced by MSU to establish in vitro AGA cell model. The concentrations of cytokines such as IL-1β, IL-8, and TNF-α were tested by ELISA. Luciferase reporter gene analysis was used to verify the interaction between H19 and the 3'-UTR of miR-22-3p. Expressions of serum H19 in AGA patients were significantly higher than that in controls. The ROC curve indicated the potential of H19 as a diagnostic marker for AGA. Cell experiments revealed that the downregulation of H19 significantly inhibited the expressions of IL-1β, IL-8, and TNF-α. The luciferase reporter gene assay manifested that miR-22-3p is the target gene of H19. And knockdown of miR-22-3p overturned the downregulation of inflammatory factors caused by H19 inhibition. H19 aggravated MSU-induced THP-1 inflammation by negatively targeting miR-22-3p, suggesting a new regulatory mechanism and potential therapeutic target for AGA.

Integrated analysis of transcriptome profiling of lncRNAs and mRNAs in livers of type 2 diabetes mellitus

Long noncoding RNAs (lncRNAs) influence the progression of almost all human diseases, but the participation of lncRNAs in type 2 diabetes mellitus (T2DM) has not been fully elucidated. The present study aimed to systematically compare the transcriptome profiling of lncRNAs and mRNAs in livers between T2DM patients and controls, to identify key genes associated with T2DM pathogenesis, and to predict the underlying molecular mechanisms. As a result, a total of 1,512 differentially expressed (DE) lncRNAs and 1,923 DE mRNAs were identified through microarray analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that multiple metabolic processes were dysregulated such as small molecule, organic acid, lipid and branched chain amino acid metabolism. Protein-protein interaction network was constructed and 10 hub mRNAs were identified, including EHHADH, ATM, ACOX1, PIK3R1, EGFR, UQCRFS1, HMGCL, UQCRC2, NDUFS3 and F2. RT-qPCR was conducted to verify the validity of microarray results. Then, coding-noncoding co-expression network and competing endogenous RNA (ceRNA) network were analyzed to predict the lncRNA-mRNA and lncRNA-miRNA-mRNA regulatory patterns. Subsequently, 10 key intermediating miRNAs in ceRNA networks with a node degree > 80 were identified, including hsa-miR-5692a, hsa-miR-12136, hsa-miR-5680, hsa-miR-1305, hsa-miR-6833-5p, hsa-miR-7159-5p, hsa-miR-548as-3p, hsa-miR-6873-3p, hsa-miR-1290 and hsa-miR-4768-5p. In conclusion, the present study evaluated the transcriptome profiling of lncRNAs and mRNAs in livers from T2DM patients, with a value for understanding the molecular mechanism of disease pathogenesis and identifying effective biomarkers in clinical diagnosis.

The role of long non-coding RNAs in the regulation of pancreatic beta cell identity

Type 2 diabetes (T2D) is a widespread disease affecting millions in every continental population. Pancreatic β-cells are central to the regulation of circulating glucose, but failure in the maintenance of their mass and/or functional identity leads to T2D. Long non-coding RNAs (lncRNAs) represent a relatively understudied class of transcripts which growing evidence implicates in diabetes pathogenesis. T2D-associated single nucleotide polymorphisms (SNPs) have been identified in lncRNA loci, although these appear to function primarily through regulating β-cell proliferation. In the last decade, over 1100 lncRNAs have been catalogued in islets and the roles of a few have been further investigated, definitively linking them to β-cell function. These studies show that lncRNAs can be developmentally regulated and show highly tissue-specific expression. lncRNAs regulate neighbouring β-cell-specific transcription factor expression, with knockdown or overexpression of lncRNAs impacting a network of other key genes and pathways. Finally, gene expression analysis in studies of diabetic models have uncovered a number of lncRNAs with roles in β-cell function. A deeper understanding of these lncRNA roles in maintaining β-cell identity, and its deterioration, is required to fully appreciate the β-cell molecular network and to advance novel diabetes treatments.

Berberine combined with stachyose improves glycometabolism and gut microbiota through regulating colonic microRNA and gene expression in diabetic rats

AIMS

Berberine is effective for type 2 diabetes mellitus (T2DM), but has limited use in clinic. This study aims to evaluate the effect of berberine combined with stachyose on glycolipid metabolism and gut microbiota and to explore the underlying mechanisms in diabetic rats.

MAIN METHODS

Zucker diabetic fatty (ZDF) rats were orally administered berberine, stachyose and berberine combined with stachyose once daily for 69 days. The oral glucose tolerance and levels of blood glucose, insulin, triglyceride and total cholesterol were determined. The gut microbial profile, colonic miRNA and gene expression were assayed using Illumina sequencing. The quantitative polymerase chain reaction was used to verify the expression of differentially expressed miRNAs and genes.

KEY FINDINGS

Repeated treatments with berberine alone and combined with stachyose significantly reduced the blood glucose, improved the impaired glucose tolerance, and increased the abundance of beneficial Akkermansiaceae, decreased that of pathogenic Enterobacteriaceae in ZDF rats. Furthermore, combined treatment remarkably decreased the abundances of Desulfovibrionaceae and Proteobacteria in comparison to berberine. Combined treatment evidently decreased the expression of intestinal early growth response protein 1 (Egr1) and heparin-binding EGF-like growth factor (Hbegf), and significantly increased the expression of miR-10a-5p, but berberine alone not.

SIGNIFICANCE

Berberine combined with stachyose significantly improved glucose metabolism and reshaped gut microbiota in ZDF rats, especially decreased the abundance of pathogenic Desulfovibrionaceae and Proteobacteria compared to berberine alone, providing a novel strategy for treating T2DM. The underlying mechanisms may be associated with regulating the expression of intestinal Egr1, Hbegf and miR-10a-5p, but remains further elucidation.

Long noncoding RNA GAS5 in age-related diseases

Aging refers to a natural process and a universal phenomenon in all cells, tissues, organs and the whole organism. Long non-coding RNAs (lncRNAs) are non-coding RNAs with the length of 200 nucleotides. LncRNA growth arrest-specific 5 (lncRNA GAS5) is often down-regulated in cancer. The accumulation of lncRNA GAS5 has been found to be able to inhibit cancer growth, invasion and metastasis, while enhancing the sensitivity of cells to chemotherapy drugs. LncRNA GAS5 can be a signaling protein, which is specifically transcribed under different triggering conditions. Subsequently, it is involved in signal transmission in numerous pathways as a signal node. LncRNA GAS5, with a close relationship to multiple miRNAs, was suggested to be involved in the signaling pathway under three action modes (i.e., signal, bait and guidance). LncRNA GAS5 was found to be involved in different age-related diseases (e.g., rheumatoid arthritis, type 2 diabetes, atherosclerosis, osteoarthritis, osteoporosis, multiple sclerosis, cancer etc.). This study mainly summarized the regulatory effect exerted by lncRNA GAS5 on age-related diseases.

LncRNA PTGS2 regulates islet β-cell function through the miR-146a-5p/RBP4 axis and its diagnostic value in type 2 diabetes mellitus

OBJECTIVE

To investigate the effect of long non-coding RNA (LncRNA) PTGS2 on islet β-cell function via the miR-146a-5p/Retinol binding protein 4 (RBP4) axis and its diagnostic value in type 2 diabetes mellitus (T2DM).

METHODS

The Gene Expression Omnibus (GEO) was analyzed and LncRNA PTGS2 was identified as a potential regulator of T2DM. Mouse pancreatic β cell INS-1 cells were cultured with high glucose, and the relative expression of LncRNA PTGS2 in the serum of T2DM patients and INS-1 cells was detected by Fluorescence Quantitative PCR (qRT-PCR) and its diagnostic value for T2DM was analyzed. The PTGS2/miR-146a-5p/RBP4 axis in INS-1 cells was intervened to observe the changes in cell function. The proliferation of INS-1 cells was detected by CCK8, and the level of insulin secretion was detected by enzyme linked immunosorbent assay (ELISA). The regulatory relationship among LncRNA PTGS2, miR-146a-5p and RBP4 was determined by dual-luciferase reporter assay.

RESULTS

The expression of LncRNA PTGS2 in the serum of T2DM patients increased, and the expression of LncRNA PTGS2 was positively correlated with the fasting blood glucose level of patients (R=0.306, P<0.05). Knockdown of LncRNA PTGS2 could promote the proliferation and insulin secretion of INS-1 cells, while overexpression of LncRNA PTGS2 showed the opposite results (all P<0.05). Knockdown of LncRNA PTGS2 could up-regulate the expression of miR-146a-5p. Overexpression of LncRNA PTGS2 inhibited the proliferation and insulin secretion of INS-1 cells, while miR-146a-5p could partially reverse this effect. RBP4 has been identified as a downstream target gene of miR-146a-5p. Overexpression of miR-146a-5p could inhibit the expression of RBP4, which was positively correlated withLncRNA PTGS2 regulation. The effect of RBP4 on INS-1 cells was the same as that of LncRNA PTGS2.

CONCLUSION

LncRNA PTGS2 can damage islet β-cell function by regulation of miR-146a-5p and up-regulation of RBP4. LncRNA PTGS2 has potential value in the diagnosis of T2DM.

Long Non-Coding RNAs (lncRNAs) in Cardiovascular Disease Complication of Type 2 Diabetes

The discovery of non-coding RNAs (ncRNAs) has opened a new paradigm to use ncRNAs as biomarkers to detect disease progression. Long non-coding RNAs (lncRNA) have garnered the most attention due to their specific cell-origin and their existence in biological fluids. Type 2 diabetes patients will develop cardiovascular disease (CVD) complications, and CVD remains the top risk factor for mortality. Understanding the lncRNA roles in T2D and CVD conditions will allow the future use of lncRNAs to detect CVD complications before the symptoms appear. This review aimed to discuss the roles of lncRNAs in T2D and CVD conditions and their diagnostic potential as molecular biomarkers for CVD complications in T2D.