Combined analysis of circRNA and mRNA profiles and interactions in patients with Diabetic Foot and Diabetes Mellitus

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.

Circular RNA PIP5K1A Promotes Glucose and Lipid Metabolism Disorders and Inflammation in Type 2 Diabetes Mellitus

Disorders of glucose and lipid metabolism are an important cause of type 2 diabetes mellitus (T2DM). Identifying the molecular mechanism of metabolic disorders is key to the treatment of T2DM. The study was to investigate the effect of circRNA PIP5K1A (circPIP5K1A) on glucose and lipid metabolism and inflammation in T2DM rats. A T2DM rat model was established, and then the T2DM rats were injected with lentiviral vectors that interfere with circPIP5K1A, miR-552-3p, or ENO1 expression. Fasting blood glucose (FBG) and fasting insulin (FINS) levels of rats were detected by an automatic analyzer and insulin detection kit, and HOMA-IR was calculated. Lipid metabolism was assessed by measuring serum levels of TG, TC, LDL-C, leptin, and resistin. Serum levels of inflammatory factors (TNF-α and IL-6) were detected by ELISA. The pathological conditions of pancreatic tissue were observed by HE staining. circPIP5K1A, miR-552-3p and ENO1 levels were recorded. The experimental results showed that circPIP5K1A and ENO1 were up-regulated, and miR-552-3p was down-regulated in T2DM rats. Down-regulating circPIP5K1A or up-regulating miR-552-3p reduced blood glucose and lipid levels, inhibited inflammation, and improved pancreatic histopathological changes in T2DM rats. In addition, up-regulating ENO1 rescued the ameliorating effects of down-regulated circPIP5K1A on T2DM rats. In general, downregulating circPIP5K1A improves insulin resistance and lipid metabolism disorders and inhibits inflammation by targeting miR-552-3p to mediate ENO1 expression.

Effect comparison of neuroendoscopic vs. craniotomy in the treatment of adult intracranial arachnoid cyst

Purpose

Intracranial arachnoid cysts are common, accounting for about 1%-2% of intracranial space-occupying lesions. There is controversy over the method of surgical intervention, and in order to provide guidance for surgical decision making, this study compares the efficacy of craniotomy vs. neuroendoscopic surgery in treating arachnoid cysts.

Methods

The adult patients with arachnoid cyst admitted to our department from October 2016 to August 2021 were retrospectively analyzed. Thirteen adult patients were recruited, and divided into two groups: neuroendoscopic group (group A) and craniotomy group (group B). We compared the gender, age, clinical symptoms, preoperative and postoperative cyst sizes, symptom improvement, complications, length of hospital stay, and hospital costs between two groups to analyze the therapeutic effects of these two surgical methods.

Results

The cost of hospitalization in group A was significantly lower than that in group B (47,292.8 vs. 65,151.8 yuan, P < 0.05), and there was no difference in the length of hospital stay between the two groups. The preoperative cysts in group A were significantly larger than those in group B (6.38 vs. 2.97 cm, P < 0.05). In groups A and B, the short-term symptom improvement rates were 100% and 75.0%, respectively. The long-term symptom improvement rates were 77.78% and 75.0% (P > 0.05), respectively.

Conclusion

Both neuroendoscopic and craniotomy have good curative effects for the treatment of intracranial arachnoid cysts. There was no significant difference in the outcomes between the two surgical techniques. The cost of hospitalization can be reduced with neuroendoscopic surgery. Neuroendoscopic treatment is recommended for large intracranial arachnoid cysts, and craniotomy is suitable for small intracranial arachnoid cysts.

The protective mechanism of protein kinase R to inhibit neuronal ferroptosis in cerebral injury from subarachnoid hemorrhage

PURPOSE

To investigate the role and mechanism of protein kinase R (PKR) in subarachnoid hemorrhage (SAH)-mediated ferroptosis.

METHODS

A rat SAH model was constructed and treated with PKR inhibitor C16 to observe SAH and neurological impairment in rats and to detect malonaldehyde (MDA), iron ions content, ferritin heavy polypeptide 1 (FTH1) and glutathione peroxidase 4 (GPX4), and other related ferroptosis indicators in brain tissue. RNA sequencing analysis was used to investigate the mechanism of PKR, affecting the ferroptosis network of SAH.

RESULTS

SAH caused severe fundic hemorrhage, neurological impairment, MDA and iron ion accumulation, and significant decrease in GPX4 and FTH1 levels in rats. C16 treatment significantly improved the above signs caused by SAH. By RNA-seq analysis, brain tissue of SAH-treated rats with SAH and C16 differentially expressed mRNA target genes enriched in stress response and organic developmental signaling pathways.

CONCLUSION

Inhibition of PKR may improve cerebral injury after SAH by inhibiting ferroptosis, and RNA sequencing staged its mechanism of action may be related to the stress response.

Profile and Functional Prediction of Plasma Exosome-Derived CircRNAs From Acute Ischemic Stroke Patients

Stroke is one of the major causes of death and long-term disability, of which acute ischemic stroke (AIS) is the most common type. Although circular RNA (circRNA) expression profiles of AIS patients have been reported to be significantly altered in blood and peripheral blood mononuclear cells, the role of exosome-containing circRNAs after AIS is still unknown. Plasma exosomes from 10 AIS patients and 10 controls were isolated, and through microarray and bioinformatics analysis, the profile and putative function of circRNAs in the plasma exosomes were studied. A total of 198 circRNAs were differentially quantified (|log2 fold change| ≥ 1.00, p < 0.05) between AIS patients and controls. The levels of 12 candidate circRNAs were verified by qRT-PCR, and the quantities of 10 of these circRNAs were consistent with the data of microarray. The functions of host genes of differentially quantified circRNAs, including RNA and protein process, focal adhesion, and leukocyte transendothelial migration, were associated with the development of AIS. As a miRNA sponge, differentially quantified circRNAs had the potential to regulate pathways related to AIS, like PI3K-Akt, AMPK, and chemokine pathways. Of 198 differentially quantified circRNAs, 96 circRNAs possessing a strong translational ability could affect cellular structure and activity, like focal adhesion, tight junction, and endocytosis. Most differentially quantified circRNAs were predicted to bind to EIF4A3 and AGO2—two RNA-binding proteins (RBPs)—and to play a role in AIS. Moreover, four of ten circRNAs with verified levels by qRT-PCR (hsa_circ_0112036, hsa_circ_0066867, hsa_circ_0093708, and hsa_circ_0041685) were predicted to participate in processes of AIS, including PI3K-Akt, AMPK, and chemokine pathways as well as endocytosis, and to be potentially useful as diagnostic biomarkers for AIS. In conclusion, plasma exosome-derived circRNAs were significantly differentially quantified between AIS patients and controls and participated in the occurrence and progression of AIS by sponging miRNA/RBPs or translating into proteins, indicating that circRNAs from plasma exosomes could be crucial molecules in the pathogenesis of AIS and promising candidates as diagnostic biomarkers and therapeutic targets for the condition.

The progress and challenges of circRNA for diabetic foot ulcers: A mini-review

Since the Human Genome Project was successfully completed, humanity has entered a post-genome era, and the second-generation sequencing technology has gradually progressed and become more accurate. Meanwhile, circRNAs plays a crucial role in the regulation of diseases and potential clinical applications has gradually attracted the attention of physicians. However, the mechanisms of circRNAs regulation at the cellular and molecular level of diabetic foot ulcer (DFU) is still not well-understood. With the deepening of research, there have been many recent studies conducted to explore the effect of circRNAs on DFU. In this mini-review, we discuss the potential role of circRNAs as therapeutic targets and diagnostic markers for DFU in order to gain a better understanding of the molecular mechanisms that underlie the development of DFU and to establish a theoretical basis for accurate treatment and effective prevention.

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.

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.

Cell Therapy for Critical Limb Ischemia: Advantages, Limitations, and New Perspectives for Treatment of Patients with Critical Diabetic Vasculopathy

PURPOSE OF REVIEW

To provide a highlight of the current state of cell therapy for the treatment of critical limb ischemia in patients with diabetes.

RECENT FINDINGS

The global incidence of diabetes is constantly growing with consequent challenges for healthcare systems worldwide. In the UK only, NHS costs attributed to diabetic complications, such as peripheral vascular disease, amputation, blindness, renal failure, and stroke, average £10 billion each year, with cost pressure being estimated to get worse. Although giant leaps forward have been registered in the scope of early diagnosis and optimal glycaemic control, an effective treatment for critical limb ischemia is still lacking. The present review aims to provide an update of the ongoing work in the field of regenerative medicine. Recent advancements but also limitations imposed by diabetes on the potential of the approach are addressed. In particular, the review focuses on the perturbation of non-coding RNA networks in progenitor cells and the possibility of using emerging knowledge on molecular mechanisms to design refined protocols for personalized therapy. The field of cell therapy showed rapid progress but has limitations. Significant advances are foreseen in the upcoming years thanks to a better understanding of molecular bottlenecks associated with the metabolic disorders.

An update on potential biomarkers for diagnosing diabetic foot ulcer at early stage

As one of major chronic complications of diabetes, diabetic foot ulcer (DFU) is the main cause of disability and death. The clinical diagnosis and prognosis of DFU is inadequate. For clinicians, if the risk stratification of DFU can be obtained earlier in diabetic patients, the hospitalization, disability and mortality rate will be reduced. In addition to the inflammatory biomarkers that have been widely concerned and used, e.g., procalcitonin, pentraxin-3, C-reactive protein (CRP), interleukins (ILs), and tumor necrosis factor-α (TNF-α), etc., a more comprehensive prediction of the risk and severity of DFU is needed to reflect new biomarkers for therapeutic intervention effects. Along with the development of systems biology technology, genomics, proteomics, metabolomics and microbiome have been used in the studies on DFU for better understanding of the disease. In this review, new biomarkers that are expected to assist in the accurate diagnosis and risk stratification of DFU will be discussed and summarized in detail.

Combined analysis of circRNA and mRNA profiles and interactions in patients with Diabetic Foot and Diabetes Mellitus

In order to elucidate the pathogenesis and explore new biomarkers for diabetes and diabetic foot (DF), an analysis using RNA sequencing affords broader insights into gene expression regulatory networks in DF. To better explore the molecular basis of DF, we carried out an analysis of circular RNA (circRNA) and messenger RNA (mRNA) expression profiles of serum samples from DF patients and diabetes mellitus (DM) patients. The potential roles and interactions of differentially expressed circRNAs and mRNAs were classified by gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Compared with diabetes patients, 279 mRNAs were upregulated and 353 mRNAs were downregulated in the serum of DF patients, and 33 circRNAs were differently expressed. The differential genes at the nodes of the interaction network were screened, and TLR6 RUNX1 and ST2 were found to be related to the progression of diabetes and DF. The enrichment pathway analysis revealed that the lysosomal pathway played a critical role in the occurrence and development of DF. TLR6, RUNX1, and ST2 mRNA expressions and the lysosomal pathway may be involved in the pathogenesis of diabetes and DF. In addition, methane metabolism and Chagas disease pathways were observed in the occurrence and development of DF, which is a new discovery in this study. This study provides clues on the molecular mechanisms of DF at the circRNA and mRNA levels.