Insights from Dysregulated mRNA Expression Profile of β-Cells in Response to Proinflammatory Cytokines

Hypoxia-induced adipose derived stem cells-derived exosomes promote diabetic wound healing through circ-0001747/miR-199a-5p/HIF-1α axis

Diabetic foot ulcers (DFU) are a serious complication of diabetes that lead to significant morbidity and mortality. The studies reported that promoting angiogenesis is a key step in wound healing. Hypoxia-induced adipose-derived mesenchymal stem cell-derived exosomes (ADSC-Exo) were observed to promote skin wound healing and alleviate DFU development. Howere, the detailed molecular mechanism of hypoxia-induced ADSC-Exo in wound healing of DFU remain undetermined. In this study, we identified aberrantly expressed circRNAs in normoxic-induced ADSC-Exo (Exo) versus hypoxia-induced ADSC-Exo (HExo) by high-throughput sequencing. The expression of circ-0001747 in Exo and HExo were detected by qRT-PCR. Subsequently, the overexpression of circ_0001747-HExo was constructed to observe the wound healing and therapeutic effect of DFU mice. Bioinformatics analysis, luciferase reporter gene assays, qRT-PCR, flow cytometry and angiogenesis assay, were used to study the regulatory mechanism of circ-0001747. The results showed that circ-0001747 was higher in HExo. Compared with the Exo group, overexpression of circ-0001747-HExo significantly restored wound healing, promoted vascular differentiation, and inhibited cell apoptosis and ROS production. Additionally, miR-199a-5p and HIF1α were identified as downstream targets of circ-0001747 and further verified by luciferase reporter gene analysis. Notably, overexpression of miR-199a-5p or inhibition of HIF1α reversed the protective effects of the circ-0001747-mediated microenvironment on endothelial cells. These results showed that overexpression of circ-0001747-HExo inhibited endothelial cell damage and promotes wound healing by targeting the miR-199a-5p/HIF1α axis.

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.

Circulating circular RNA profiles associated with celiac disease seropositivity in children with type 1 diabetes

INTRODUCTION

The frequency of celiac disease autoantibody (CDAb) positivity in type 1 diabetes (T1D) has increased due to unclear mechanisms, including autoimmune injury. Circular ribonucleic acids (circRNAs) participate in autoimmune diseases, but the roles of circRNAs in T1D with CDAbs are currently unknown. This study aimed to determine the frequency of CDAbs in Chinese children with T1D and describe the relationship between CDAbs and circRNAs.

MATERIALS AND METHODS

Eighty patients diagnosed with T1D were screened for CDAbs and CD-predisposing genes, and circRNAs in peripheral blood mononuclear cells (PBMCs) were collected from 47 patients. The Gene Expression Omnibus (GEO) database was searched for candidate circRNAs in related studies on T1D PBMCs. Data on clinical characteristics (i.e., blood glucose control, residual islet function, and daily insulin dosage) and immunophenotypes (i.e., islet autoantibodies and immune cell subsets) were collected.

RESULTS

In total, 35.0% of patients were positive for CDAbs. CD-predisposing genes accounted for 52.5% of the genes, and no significant difference in frequency was found between the CDAb-positive (CDAb⁺) and CDAb-negative (CDAb^-) groups. In addition, among the differentially expressed circRNAs from the GEO database, five highly conserved circRNAs homologous to humans and mice were screened, and only the expression of hsa_circ_0004564 in the CDAb⁺ group significantly decreased (CDAb⁺ vs. CDAb^-:1.72 ± 1.92 vs. 11.12 ± 8.59, p = 6.0 × 10^-6), while the expression of hsa_circ_0004564 was upregulated in the general T1D population. Moreover, its parental gene RAPH1 was significantly upregulated (CDAb⁺ vs. CDAb^-:1.26 ± 0.99 vs. 0.61 ± 0.46, p = 0.011). Importantly, the positive correlation between hsa_circ_0004564 and CD3⁺ cells was validated in children with T1D after adjustments for CDAbs (p = 0.029), while there were no correlations between hsa_circ_0004564 and clinical characteristics or other immune cell subsets (i.e., CD4⁺ T cells, CD8⁺ T cells, and natural killer cells).

CONCLUSION

This study highlights the importance of screening for CD in Chinese children with T1D, considering the high prevalence of CDAb positivity and CD-predisposing genes. The profile of candidate circRNAs in children with T1D with CDAbs was different from that in previous reports on general T1D patients from the GEO database. Moreover, hsa_circ_0004564 and its parental gene RAPH1 may be new targets for studying immune mechanisms in children with T1D and CD.