Identification of potential circRNAs and circRNA-miRNA-mRNA regulatory network in the development of diabetic foot ulcers by integrated bioinformatics analysis

Exosomes: compositions, biogenesis, and mechanisms in diabetic wound healing

Diabetic wounds are characterized by incomplete healing and delayed healing, resulting in a considerable global health care burden. Exosomes are lipid bilayer structures secreted by nearly all cells and express characteristic conserved proteins and parent cell-associated proteins. Exosomes harbor a diverse range of biologically active macromolecules and small molecules that can act as messengers between different cells, triggering functional changes in recipient cells and thus endowing the ability to cure various diseases, including diabetic wounds. Exosomes accelerate diabetic wound healing by regulating cellular function, inhibiting oxidative stress damage, suppressing the inflammatory response, promoting vascular regeneration, accelerating epithelial regeneration, facilitating collagen remodeling, and reducing scarring. Exosomes from different tissues or cells potentially possess functions of varying levels and can promote wound healing. For example, mesenchymal stem cell-derived exosomes (MSC-exos) have favorable potential in the field of healing due to their superior stability, permeability, biocompatibility, and immunomodulatory properties. Exosomes, which are derived from skin cellular components, can modulate inflammation and promote the regeneration of key skin cells, which in turn promotes skin healing. Therefore, this review mainly emphasizes the roles and mechanisms of exosomes from different sources, represented by MSCs and skin sources, in improving diabetic wound healing. A deeper understanding of therapeutic exosomes will yield promising candidates and perspectives for diabetic wound healing management.

Non-coding RNAs in diabetic foot ulcer- a focus on infected wounds

Diabetes mellitus is associated with a wide range of neuropathies, vasculopathies, and immunopathies, resulting in many complications. More than 30% of diabetic patients risk developing diabetic foot ulcers (DFUs). Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play essential roles in various biological functions in the hyperglycaemic environment that determines the development of DFU. Ulceration results in tissue breakdown and skin barrier scavenging, thereby facilitating bacterial infection and biofilm formation. Many bacteria contribute to diabetic foot infection (DFI), including Staphylococcus aureus (S. aureus) et al. A heterogeneous group of "ncRNAs," termed small RNAs (sRNAs), powerfully regulates biofilm formation and DFI healing. Multidisciplinary foot care interventions have been identified for nonhealing ulcers. With an appreciation of the link between disease processes and ncRNAs, a novel therapeutic model of bioactive materials loaded with ncRNAs has been developed to prevent and manage diabetic foot complications.

Identification of autophagy-related genes in diabetic foot ulcer based on bioinformatic analysis

Diabetic foot ulcer (DFU) complications involve autophagy dysregulation. This study aimed to identify autophagy-related bioindicators in DFU. Differentially expressed genes (DEGs) between DFU and healthy samples were analysed from the Gene Expression Omnibus (GEO) datasets, GSE7014 and GSE29221. The roles of autophagy-related DEGs were investigated using protein-protein interaction (PPI) networks, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, Gene Ontology (GO) enrichment, and Gene Set Enrichment Analysis (GSEA). Immune cell infiltration's correlation with these DEGs was also assessed. From the Human Autophagy Database (HADB), 232 autophagy-related genes (ARGs) were identified, with an intersection of 17 key DEGs between GSE7014 and GSE29221. These genes are involved in pathways like autophagy-animal, NOD-like receptor signalling, and apoptosis. In the protein network, epidermal growth factor receptor (EGFR) and phosphatase and tensin homologue (PTEN) showed significant interactions with ARGs. Survival analysis indicated the prognostic importance of calpain 2 (CAPN2), integrin subunit beta 1 (ITGB1), and vesicle-associated membrane protein 3 (VAMP3). Lower immune scores were observed in the type 2 diabetes mellitus (DM2) group than in controls. Autophagy and ARGs significantly influence DFU pathophysiology.

Understanding molecular mechanisms and miRNA-based targets in diabetes foot ulcers

In today's culture, obesity and overweight are serious issues that have an impact on how quickly diabetes develops and how it causes complications. For the development of more effective therapies, it is crucial to understand the molecular mechanisms underlying the chronic problems of diabetes. The most prominent effects of diabetes are microvascular abnormalities such as retinopathy, nephropathy, and neuropathy, especially diabetes foot ulcers, as well as macrovascular abnormalities such as heart disease and atherosclerosis. MicroRNAs (miRNAs), which are highly conserved endogenous short non-coding RNA molecules, have been implicated in several physiological functions recently, including the earliest stages of the disease. By binding to particular messenger RNAs (mRNAs), which cause mRNA degradation, translation inhibition, or even gene activation, it primarily regulates posttranscriptional gene expression. These molecules exhibit considerable potential as diagnostic biomarkers for disease and are interesting treatment targets. This review will provide an overview of the latest findings on the key functions that miRNAs role in diabetes and its complications, with an emphasis on the various stages of diabetic wound healing.

Decrypting the circular RNAs does a favor for us: Understanding, diagnosing and treating diabetes mellitus and its complications

Circular RNAs (circRNAs), a novel type of single-stranded noncoding RNAs with a covalently closed loop structure, are generated in a circular conformation via non-canonical splicing or back-splicing events. Functionally, circRNAs have been elucidated to soak up microRNAs (miRNAs) and RNA binding proteins (RBPs), serve as protein scaffolds, maintain mRNA stability, and regulate gene transcription and translation. Notably, circRNAs are strongly implicated in the regulation of β-cell functions, insulin resistance, adipocyte functions, inflammation as well as oxidative stress via acting as miRNA sponges and RBP sponges. Basic and clinical studies have demonstrated that aberrant alterations of circRNAs expressions are strongly associated with the initiation and progression of diabetes mellitus (DM) and its complications. Here in this review, we present a summary of the biogenesis, transportation, degradation and functions of circRNAs, and highlight the recent findings on circRNAs and their action mechanisms in DM and its complications. Overall, this review should contribute greatly to our understanding of circRNAs in DM pathogenesis, offering insights into the further perspectives of circRNAs for DM diagnosis and therapy.

Circ_072697 knockdown promotes advanced glycation end products-induced cell proliferation and migration in HaCaT cells via miR-3150a-3p/KDM2A axis

OBJECTIVE

Diabetes foot ulcer (DFU) is a serious complication of diabetes, which can lead to significant mortality and amputation rate. Our previous study found circ_072697 was highly expressed in DFU tissues, but the regulatory mechanism of circ_072697 in DFU remains unclear.

METHODS

The relative expressions of circ_072697, miR-3150a-3p, and KDM2A in DFU patients or advanced glycation end products (AGEs)-treated HaCaT cells (used as DFU cell model) were determined by using qRT-PCR. Cell proliferation and migration abilities were determined by using CCK-8 and Transwell assays. The interaction between miR-3150a-3p with circ_072697 or KDM2A were verified by RNA immunoprecipitation (RIP) and dual-luciferase reporter assays. Furthermore, the protein expression of genes involved in MAPK signaling pathway was detected by western blot.

RESULTS

The expression of circ_072697 was significantly upregulated in DFU tissues, while the expression of miR-3150a-3p was downregulated. Circ_072697 knockdown promoted the proliferation and migration of AGEs-treated HaCaT cells. miR-3150a-3p was confirmed as a target of circ_072697 and its inhibitor reversed the promotion effects of circ_072697 knockdown on biological behavior of cells. In addition, KDM2A was considered as a target of miR-3150a-3p and it was highly expressed in DFU samples. Importantly, circ_072697 could regulate KDM2A expression through sponging miR-3150a-3p, and this axis had effect on the MAPK signaling pathway.

CONCLUSIONS

Overall, circ_072697 regulated the biological behaviors of keratinocytes in DFU via miR-3150a-3p/KDM2A axis and MAPK signaling pathway, revealing a new insight into the pathogenesis and potential therapeutic targets of DFU.

UCMSCs-derived exosomal circHIPK3 promotes ulcer wound angiogenesis of diabetes mellitus via miR-20b-5p/Nrf2/VEGFA axis

AIMS

Experiments confirmed that circular RNAs contributed to the pathogenesis of diabetic foot ulcers (DFUs). CircHIPK3 was upregulated in type 2 diabetes mellitus (T2DM), but its role in DFU remained unknown. Our study aimed to investigate the regulatory functions of exosomal circHIPK3 and its potential mechanisms in DFU.

METHODS

Exosomal size and distribution, marker proteins, and circHIPK3 levels were evaluated by transmission electron microscope, ExoView R200, western blot, and qRT-PCR. Flow cytometry, MTT, Wound healing assays, and tube formation assays were used to assess the roles of exosomal circHIPK3 in high glucose (HG)-treated human umbilical vein endothelial cells (HUVECs). The relationships between Nrf2/VEGFA/circHIPK3 and miR-20b-5p, and between Nrf2 and VEGFA were determined by luciferase reporter assay and RNA immunoprecipitation. We used cell and mice models to investigate the mechanisms of exosomal circHIPK3 under diabetic conditions.

RESULTS

CircHIPK3 was significantly upregulated in exo-circHIPK3 rather than exo-vector. Exo-circHIPK3 remarkably inhibited cell apoptosis but promoted cell proliferation, migration, and tube formation in HG-treated HUVECs. Luciferase reporter and RIP assays showed that miR-20b-5p targeted and inhibited Nrf2 and VEGFA, and circHIPK3 acted as a ceRNA of miR-20b-5p to inhibit the binding to its downstream genes Nrf2 and VEGFA. Mechanistically, circHIPK3 promoted cell proliferation, migration, and angiogenesis via downregulating miR-20b-5p to upregulate Nrf2 and VEGFA. However, the overexpressed miR-20b-5p could abolish the promoting effects of circHIPK3 overexpression on cell proliferation, migration, and tube formation under HG conditions.

CONCLUSION

UCMSCs-derived exosomal circHIPK3 protected HG-treated HUVECs via miR-20b-5p/Nrf2/VEGFA axis. The exosomal circHIPK3 might be a therapeutic candidate to treat DFU.

S, Shetty P, Prakash Patil. Molecular signatures in diabetic foot ulcer by integrated gene expression profiling via bioinformatics analysis

Introduction and Aim: Diabetic foot ulcers (DFUs) are a common and debilitating diabetic consequence leading to lower-limb amputations, long-term disability, and reduced lifespan. There is a lack of clinical diagnosis expertise because of no adequate diagnostic signs for DFU. As a result, the current research aims to find out how differently expressed genes (DEGs) affect the DFU. Materials and Methods: Bioinformatics analysis was used to evaluate DEGs using the GSE132187 dataset of the NCBI-GEO database, which contained samples from three hyperglycemic and three normoglycemic macrophage-like cell lines. Following the discovery of DEGs, Gene Ontology (GO) and KEGG pathway enrichment analysis were used to investigate how genes are classified into preset bins based on their functional properties. To discover hub DEGs in DFU, a protein-protein interaction (PPI) network was built and five topological parameters such as degree, stress, Closeness centrality, betweenness centrality, and radiality were evaluated. Results: We found 547 DEGs using the GSE132187 dataset, comprising 79 upregulated DEGs and 468 downregulated DEGs. There were 434 nodes and 1724 edges in the PPI network. The giant network uncovered six modules that are significantly enriched in biological processes like positive JNK cascade regulation, positive interferon-gamma production regulation, negative cell proliferation regulation, cellular response to zinc ion, cellular response to lipopolysaccharide, wound healing, and inflammatory response. Conclusion: Bioinformatics analysis revealed the major differentially expressed hub-genes implicated in DFUs. These findings suggested that these genes could be used as a DFU prognostic, diagnostic, or therapeutic targets.

CircSLC8A1 targets miR-181a-5p/HIF1AN pathway to inhibit the growth, migration and extracellular matrix deposition of human keloid fibroblasts

BACKGROUND

Circular RNAs (circRNAs) are identified as important regulators in human diseases, including keloid. The purpose of this study is to reveal the role and molecular mechanism of circSLC8A1 in keloid formation.

METHODS

Expression of circSLC8A1, microRNA (miR)-181a-5p, and hypoxia inducible factor 1 alpha inhibitor (HIF1AN) were detected by quantitative real-time PCR. Protein expression of extracellular matrix (ECM) deposition markers and HIF1AN was detected by western blot analysis. Furthermore, the interaction between miR-181a-5p and circSLC8A1 or HIF1AN was confirmed by dual-luciferase reporter assay, RIP assay and RNA pull-down assay.

RESULTS

Expression of circSLC8A1 was downregulated in keloid tissues and HKFs. Overexpression of circSLC8A1 suppressed HKFs proliferation, migration, ECM deposition, and promoted apoptosis. MiR-181a-5p is targeted by circSLC8A1, and its mimic reversed the effect of circSLC8A1 on the biological function of HKFs. HIF1AN was a target of miR-181a-5p, and it was positively regulated by circSLC8A1. Knockdown of HIF1AN also reversed the negatively regulation of circSLC8A1 on the biological functions of HKFs.

CONCLUSION

Our data showed that circSLC8A1 regulates the miR-181a-5p/HIF1AN axis to restrain HKFs biological functions, confirming that circSLC8A1 might serve as a novel therapeutic target for keloids.

Circ_0003645 serves as miR-335-5p sponge to promote the biological process of diffuse large B-cell lymphoma by upregulating NFIB

BACKGROUND

Circular RNAs (circRNAs) are critical regulators for the development of many tumours, including diffuse large B-cell lymphoma (DLBCL). However, the role and mechanism of circ_0003645 in DLBCL progression remains obscure.

METHODS

Quantitative real-time PCR was performed to measure the expression of circ_0003645, microRNA (miR)-335-5p and nuclear factor I/B (NFIB). Cell viability, apoptosis and cell cycle were measured by cell counting kit 8 assay and flow cytometry. Protein expression was assessed using western blot analysis, and cell glycolysis was evaluated by detecting glucose consumption and ATP/ADP ratios. Besides, dual-luciferase reporter assay and RIP assay were used to confirm RNA interaction.

RESULTS

Our data showed that circ_0003645 expression was significantly upregulated in DLBCL tumour tissues. After circ_0003645 knockdown, the viability, cell cycle and glycolysis of DLBCL cells were inhibited, while cell apoptosis was promoted. MiR-335-5p could be sponged by circ_0003645, and NFIB was confirmed to be a downstream target of miR-335-5p. Function analysis revealed that anti-miR-335-5p reversed the regulation of si-circ_0003645 on DLBCL cell progression, and NFIB overexpression also abolished miR-335-5p-mediated the biological functions of DLBCL cells.

CONCLUSION

The present study revealed that circ_0003645 promoted the proliferation and glycolysis of DLBCL cells by the miR-335-5p/NFIB axis, which might provide a novel insight for DLBCL treatment.

Circular RNAs in diabetes mellitus and its complications

Diabetes mellitus (DM) is an endocrine disorder characterized by a relative or absolute lack of insulin due to the dysfunction or destruction of β-cells. DM is one of the fastest growing challenges to global health in the 21^st century and places a tremendous burden on affected individuals and their families and countries. Although insulin and antidiabetic drugs have been used to treat DM, a radical cure for the disease is unavailable. The pathogenesis of DM remains unclear. Emerging roles of circular RNAs (circRNAs) in DM have become a subject of global research. CircRNAs have been verified to participate in the onset and progression of DM, implying their potential roles as novel biomarkers and treatment tools. In the present review, we briefly introduce the characteristics of circRNAs. Next, we focus on specific roles of circRNAs in type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus and diabetes-associated complications.

Circular RNA: A promising new star for the diagnosis and treatment of colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract. According to the research of circular RNAs in the CRC field, compared with linear RNAs, circular RNAs are a special type of noncoding RNA that are covalently closed circular structures, which have no 5' cap structure and 3' polyA tail and are not affected by RNA exonuclease and actinomycin D.

Biological functions

Notably, circular RNAs have a high degree of stability and potential effect on gene regulation. Meanwhile, circular RNAs are involved in the sponge action of microRNAs and mediate protein translation and direct binding, alternative splicing, and histone modification.

Relationships with CRC

Studies have shown that circular RNAs are related to the proliferation, invasion, recurrence, metastasis, ferroptosis, apoptosis, and chemotherapy resistance of CRC.

Conclusions

This article provides a brief review based on the source, structural characteristics, mechanisms, biological functions of circular RNAs, and the relationships between CRC.

Diabetic Wound-Healing Science

Diabetes mellitus is an increasingly prevalent chronic metabolic disease characterized by prolonged hyperglycemia that leads to long-term health consequences. It is estimated that impaired healing of diabetic wounds affects approximately 25% of all patients with diabetes mellitus, often resulting in lower limb amputation, with subsequent high economic and psychosocial costs. The hyperglycemic environment promotes the formation of biofilms and makes diabetic wounds difficult to treat. In this review, we present updates regarding recent advances in our understanding of the pathophysiology of diabetic wounds focusing on impaired angiogenesis, neuropathy, sub-optimal chronic inflammatory response, barrier disruption, and subsequent polymicrobial infection, followed by current and future treatment strategies designed to tackle the various pathologies associated with diabetic wounds. Given the alarming increase in the prevalence of diabetes, and subsequently diabetic wounds, it is imperative that future treatment strategies target multiple causes of impaired healing in diabetic wounds.

Bioinformatics Analysis Predicts hsa_circ_0026337/miR-197-3p as a Potential Oncogenic ceRNA Network for Non-small Cell Lung Cancers

BACKGROUND

Circular RNAs (circRNAs) play an essential role in developing tumors, but their role in non-small cell lung cancer (NSCLC) is unclear. Thus, the present study explored the possible molecular mechanism of circRNAs in NSCLC.

METHODS

Three circular RNA (circRNA) microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differential expressions of circRNAs (DECs) were identified in NSCLC tissue and compared to adjacent healthy tissue. The online cancer-specific circRNA database (CSCD) was used for the analysis of the DECs function. Protein-protein interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), Cytoscape, and UALCAN were used to predict the critical nodes and perform patient survival analysis, respectively. The interaction between the DECs, the predicted miRNAs, and hub genes was also determined. Finally, the circRNA-miRNA-mRNA network was established.

RESULTS

The expression of hsa_circ_0049271, hsa_circ_0026337, hsa_circ_0043256, and hsa_circ_0008234 was decreased in NSCLC tissues. The Encyclopedia of RNA Interactomes (ENCORI) and CSCD database results showed that hsa_circ_0026337 was found to sponge with miR-1193, miR-197-3p, miR-3605-5p, miR-433-3p, and miR-652-3p, and hsa_circ_0043256 to sponge with miR-1252-5p, miR-494-3p, and miR-558, respectively. Subsequently, 100 mRNAs were predicted to bind with these seven miRNA response elements (MREs). The GO analysis and KEGG pathway revealed that these 100 MREs might be involved in "histone deacetylase binding" and "cellular senescence". PPI network and Cytoscape identified the top ten hub genes. Survival analysis data showed that the low expression of hsa_circ_0026337 was significantly associated with shortened survival time in NSCLC (P=0.037), which increased the expression level of hsa-miR-197-3p, thereby inhibiting the translation of specific proteins.

CONCLUSION

This study examined the circRNA-miRNA-mRNA regulatory network associated with NSCLC and explored the potential functions of DECs in the network to elucidate the mechanisms underlying disease progression in NSCLC.

CircPAG1 Inhibits the High Glucose-Induced Lens Epithelial Cell Injury by Sponging miR-630 and Upregulating EPHA2

Background: Circular RNAs (circRNAs) have been considered as vital regulators in the progression of human ocular diseases, including diabetic cataract (DC). This report was designed to research the biological role of circRNA phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (circPAG1) in high glucose (HG)-induced lens epithelial damages.Methods: Lens epithelial damage in DC was investigated by the effects of 25 mM glucose (HG) on human lens epithelial cells (HLE-B3). CircPAG1, microRNA-630 (miR-630), and ephrin type-A receptor 2 (EPHA2) levels were examined by the quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation analysis was performed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay and colony formation assay. Cell apoptosis was measured through flow cytometry. Protein levels were detected using western blot. Oxidative stress was determined by malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) levels via the corresponding kits. Dual-luciferase reporter and RNA immunoprecipitation (RIP) and RNA pull-down assays were used for target binding analysis.Results: CircPAG1 expression was downregulated in lens samples of DC patients and HG-treated lens epithelial cells. HG inhibited cell growth but promoted apoptosis and oxidative stress in HLE-B3 cells, while circPAG1 overexpression relieved these damages. Moreover, circPAG1 was identified as a molecular sponge for miR-630. HG-induced cell injury was also attenuated by the inhibition of miR-630, and the function of circPAG1 was related to its sponge effect on miR-630. In addition, miR-630 directly targeted EPHA2 and circPAG1 could regulate the EPHA2 expression via sponging miR-630. Furthermore, we found that the protective role of circPAG1 against the HG-induced cell injury was ascribed to the upregulation of EPHA2.Conclusion: Our evidence suggested that circPAG1 alleviated cell damages in HG-treated human lens epithelial cells by regulating the miR-630/EPHA2 axis.

Integrated Bioinformatics-Based Identification of Potential Diagnostic Biomarkers Associated with Diabetic Foot Ulcer Development

The present study was designed to detect possible biomarkers associated with diabetic foot ulcer (DFU) incidence in an effort to develop novel treatments for this condition. The GSE7014 and GSE29221 gene expression datasets were downloaded from the Gene Expression Omnibus (GEO) database, after which differentially expressed genes (DEGs) were identified between DFU and healthy samples. These DEGs were then arranged into a protein-protein interaction (PPI) network, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) term enrichment analyses were performed to explore the functional roles of these genes. In total, 1192 DEGs were identified in the GSE7014 dataset (900 upregulated, 292 downregulated), while 1177 were identified in the GSE29221 dataset (257 upregulated, 919 downregulated). GO analyses revealed these DEGs to be significantly enriched in biological processes including sarcomere organization, muscle filament sliding, and the regulation of cardiac conduction, molecular functions including structural constituent of muscle, protein binding, and calcium ion binding, and cellular components including Z disc, myosin filament, and M band. These DEGs were also enriched in the adrenergic signaling in cardiomyoctes, dilated cardiomyopathy, and tight junction KEGG pathways. Together, the findings of these bioinformatics analyses thus identified key hub genes associated with DFU development.

Heterogeneous miRNA-mRNA Regulatory Networks of Visceral and Subcutaneous Adipose Tissue in the Relationship Between Obesity and Renal Clear Cell Carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is one of the most lethal urologic cancer. Associations of both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with ccRCC have been reported, and underlying mechanisms of VAT perhaps distinguished from SAT, considering their different structures and functions. We performed this study to disclose different miRNA-mRNA networks of obesity-related ccRCC in VAT and SAT using datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA); and find out different RNAs correlated with the prognosis of ccRCC in VAT and SAT.

METHODS

We screened out different expressed (DE) mRNAs and miRNAs of obesity, in both VAT and SAT from GEO datasets, and constructed miRNA-mRNA networks of obesity-related ccRCC. To evaluate the sensitivity and specificity of RNAs in networks of obesity-related ccRCC in both VAT and SAT, Receiver Operating Characteristic (ROC) analyses were conducted using TCGA datasets. Spearman correlation analyses were then performed to find out RNA pairs with inverse correlations. We also performed Cox regression analyses to estimate the association of all DE RNAs of obesity with the overall survival.

RESULTS

136 and 185 DE mRNAs of obesity in VAT and SAT were found out. Combined with selected DE miRNAs, miRNA-mRNA networks of obesity-related ccRCC were constructed. By performing ROC analyses, RNAs with same trend as shown in networks and statistically significant ORs were selected to be paired. Three pairs were finally remained in Spearman correlation analyses, including hsa-miR-182&ATP2B2, hsa-miR-532&CDH2 in VAT, and hsa-miR-425&TFAP2B in SAT. Multivariable Cox regression analyses showed that several RNAs with statistically significant adjusted HRs remained consistent trends as shown in DE analyses of obesity. Risk score analyses using selected RNAs showed that the overall survival time of patients in the low-risk group was significantly longer than that in the high-risk group regardless of risk score models.

CONCLUSIONS

We found out different miRNA-mRNA regulatory networks of obesity-related ccRCC for both VAT and SAT; and several DE RNAs of obesity-related ccRCC were found to remain consistent performance in terms of ccRCC prognosis. Our findings could provide valuable evidence on the targeted therapy of obesity-related ccRCC.

Identification of potential circRNAs and circRNA-miRNA-mRNA regulatory network in the development of diabetic foot ulcers by integrated bioinformatics analysis

We aimed to explore the mechanism of circular RNAs (circRNAs) and provide potential biomarkers for molecular therapy of diabetic foot ulcers (DFU). Gene expression profile of GSE114248, including five normal samples and five DFU samples, was downloaded from GEO database. Differentially expressed circRNAs (DEcircRNAs) between two groups were identified. Then, DEcircRNA‐miRNA and miRNA‐mRNA interaction was revealed, followed by the circRNA‐miRNA‐mRNA network construction. Moreover, functional and pathway analysis were performed based on mRNAs, followed by the DM‐related pathway exploration. Specific binding sites for key circRNAs and associated miRNAs were under investigation. Finally, RT‐qPCR was used to verify the candidate the relative expression level of circRNA between normal tissues and DFU. Totally, 65 DEcircRNAs were revealed between two groups, followed by 113 circRNA‐miRNA‐mRNA interactions explored. The mRNAs in these interactions were mainly assembled in functions like cell proliferation and pathways. Moreover, a total of 11 DM‐related pathways were revealed. Finally, circRNA‐miRNA specific binding‐site analysis revealed two key circRNAs, for example, circRNA_072697 and circRNA_405463, corresponding to their miRNAs. These two circRNAs were novel biomarkers for DFU. circRNA_072697 acted as a sponge of miR‐3150a‐3p in the progression of DFU via regulating KRAS. MAPK signaling pathway might contribute to the development of DFU.