Research Advances in the Roles of Circular RNAs in Pathophysiology and Early Diagnosis of Gestational Diabetes Mellitus

AKT1 and MAPK8: New Targets for Gestational Diabetes Mellitus?

Objective: Gestational diabetes mellitus (GDM) disrupts placental function and increases risks for pregnancy. This study investigates the potential involvement of AKT1 and MAPK8 genes, known for their roles in insulin resistance and cell signaling, in GDM pathophysiology. Methods: Placental tissues from GDM patients and healthy controls were analyzed using real-time PCR to quantify gene expression levels. In silico analysis further explored the functional implications of expression changes. Results: AKT1 and MAPK8 displayed significantly altered expression in GDM placentas compared to controls (p = 0.047 and p = 0.007, respectively). In silico analysis suggests potential functional consequences related to diabetes-associated pathways. Conclusion: This study identifies differential expression of AKT1 and MAPK8 in GDM placentas, suggesting their potential roles in the disease process. Further investigation into their functional contributions could provide valuable insights into GDM pathophysiology and potential therapeutic targets.

Longitudinal observation of tRNA-derived fragments profiles in gestational diabetes mellitus and its diagnostic value

BACKGROUND

Gestational Diabetes Mellitus (GDM) poses significant risks to maternal and fetal health. Current diagnostic methods based on glucose tolerance tests have limitations for early detection. tRNA-derived small RNAs (tsRNAs) have emerged as potential molecular regulators in various diseases, including metabolic disorders. However, the diagnostic value of tsRNAs in plasma for early GDM or postpartum remains unclear.

METHODS

This longitudinal study profiled the expression of tsRNAs across different gestational stages and postpartum in women with GDM (n = 40) and healthy control gestational women (HCs, n = 40). High-throughput small RNA sequencing identified candidate tsRNAs, which were then validated and correlated with clinical biochemical markers such as fasting blood glucose (FBG), HOMA-IR, and GHbA1c.

RESULTS

tRF-1:32-Val-AAC-1-M6, tRF-1:31-Glu-CTC-1-M2, and tRF-1:30-Gly-CCC-1-M4 were consistently upregulated in the GDM group compared to HCs during the second trimester (p < 0.05). Only tRF-1:31-Glu-CTC-1-M2 was highly expressed during the first trimester, and tRF-1:30-Gly-CCC-1-M4 increased during postpartum. tRF-1:31-Glu-CTC-1-M2 showed a significant correlation with FBG levels in the first trimester (R = 0.317, p = 0.047). The expression of tRF-1:30-Gly-CCC-1-M4 was significantly correlated with HOMA-IR (r = 0.65, p < 0.001) and GHBA1c (r = 0.33, p = 0.037) during postpartum. A joint diagnostic model incorporating tsRNAs expression and clinical markers demonstrated enhanced predictive power for GDM (ROC AUC = 0.768).

CONCLUSION

Our results revealed distinct expression patterns of specific tsRNAs in GDM, showcasing their correlation with key metabolic parameters. This underscores their promising role as biomarkers for early prediction and diagnosis of GDM. The integration of tRFs into a composite biomarker panel holds the potential to improve clinical outcomes by enabling personalized risk assessment and targeted interventions.

Identification of circRNA Expression Profile and Potential Systemic Immune Imbalance Modulation in Premature Rupture of Membranes

Premature rupture of membrane (PROM) refers to the rupture of membranes before the onset of labor which increases the risk of perinatal morbidity and mortality. Recently, circular RNAs (circRNAs) have emerged as promising regulators of diverse diseases. However, the circRNA expression profiles and potential circRNA-miRNA-mRNA regulatory mechanisms in PROM remain enigmatic. In this study, we displayed the expression profiles of circRNAs and mRNAs in plasma and fetal membranes of PROM and normal control (NC) groups based on circRNA microarray, the Gene Expression Omnibus database, and NCBI's Sequence Read Archive. A total of 1,459 differentially expressed circRNAs (DECs) in PROM were identified, with 406 upregulated and 1,053 downregulated. Then, we constructed the circRNA-miRNA-mRNA network in PROM, encompassing 22 circRNA-miRNA pairs and 128 miRNA-mRNA pairs. Based on the analysis of gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene set enrichment analysis (GSEA), DECs were implicated in immune-related pathways, with certain alterations persisting even postpartum. Notably, 11 host genes shared by DECs of fetal membrane tissue and prenatal plasma in PROM were significantly implicated in inflammatory processes and extracellular matrix regulation. Our results suggest that structurally stable circRNAs may predispose to PROM by mediating systemic immune imbalances, including peripheral leukocyte disorganization, local immune imbalance at the maternal-fetal interface, and local collagen disruption. This is the first time to decipher a landscape on circRNAs of PROM, reveals the pathogenic cause of PROM from the perspective of circRNA, and opens up a new direction for the diagnosis and treatment of PROM.

Characterizing the Dynamic Expression of C1q/TNF-α-Related Protein 6 (CTRP6) during Pregnancy in Humans and Mice with Gestational Diabetes Mellitus

AIM

C1q/TNF-related protein 6 (CTRP6) is a novel adipokine involved in insulin resistance. Thus, we aim to investigate the expression profile of CTRP6 in the plasma, adipose tissue and placenta of GDM patients and mice.

METHODS

Chinese Han pregnant women (GDM n = 9, control n = 10) with a scheduled caesarean section delivery were recruited. A number of high-fat diet (HFD) induced-pregnancy C57BL/6 mice were chosen as an animal model of GDM. Circulating levels of CTRP6 and adiponectin were examined by ELISA. CTRP6 expression in adipose tissue and placenta were detected by real-time qPCR and WB.

RESULT

Plasma CTRP6 levels were decreased during the first and second trimesters in mice, as well as the second and third trimesters in patients, while they were increased at delivery in GDM patients and mice. Plasma CTRP6 levels were significantly correlated with WBC, systolic pressure, diastolic pressure and fasting blood glucose. Moreover, CTRP6 mRNA expression in the subcutaneous (sWAT) and omental white adipose tissue (oWAT), as well as in the placenta, was significantly higher in GDM human patients at cesarean delivery. Furthermore, the mRNA expression of Ctrp6 was increased in the sWAT and visceral WAT (vWAT), whilst decreased in the interscapular brown adipose tissue (iBAT), of GDM mice at cesarean delivery.

CONCLUSION

Dynamically expressed CTRP6 may be served as a candidate target for treatment of GDM.

Hsa_circ_0006260 Mediates Trophoblast Function by Fibronectin Type III Domains Containing Protein 5 via Interacting with miR-770-5p

A series of studies have confirmed the relationship between circular RNAs (circRNAs) and metabolic diseases. Hsa_circ_0006260 has been reported to be lowly expressed in the placenta of gestational diabetes mellitus (GDM) patients, but the underlying mechanism and its biological functions remain obscure. Placental tissues were collected from 37 pregnant women with normal glucose tolerance (NGT) and 37 pregnant women with GDM. Expression changes of hsa_circ_0006260 in placentas and high glucose (HG)-stimulated HTR-8/SVneo cells were detected using real-time quantitative polymerase chain reaction. Cell viability and migration were determined by cell counting and transwell assays, respectively. Measurement of cytokines was done by enzyme-linked immunosorbent assay. Cell apoptosis was estimated by flow cytometry assay. The molecular mechanisms were identified using dual-luciferase reporter and RNA-binding protein immunoprecipitation assays. Hsa_circ_0006260 expression was remarkably lowered in GDM patient-derived placentas and HG-stimulated HTR-8/SVneo cells. Functionally, hsa_circ_0006260 overexpression weakened HG-mediated repression of HTR-8/SVneo cell viability and migration, as well as promotion of HTR-8/SVneo cell inflammatory response and apoptosis. Mechanistically, hsa_circ_0006260 functioned as a miR-770-5p decoy to mediate fibronectin type III domains containing protein 5 (FNDC5) expression. Ectopic expression of miR-770-5p weakened hsa_circ_0006260 overexpression-mediated repression of HG-induced HTR-8/SVneo cell dysfunction. Also, FNDC5 knockdown lessened miR-770-5p overexpression-mediated promotion of HG-induced HTR-8/SVneo cell dysfunction. Our findings manifested a novel mechanism by which hsa_circ_0006260 could lower HG-induced HTR-8/SVneo cell dysfunction by upregulating FNDC5 via binding to miR-770-5p, which shed new light on circRNA mediated GDM pathogenesis.

Value of Non-Coding RNA Expression in Biofluids to Identify Patients at Low Risk of Pathologies Associated with Pregnancy

Pregnancy-related complications (PRC) impact maternal and fetal morbidity and mortality and place a huge burden on healthcare systems. Thus, effective diagnostic screening strategies are crucial. Currently, national and international guidelines define patients at low risk of PRC exclusively based on their history, thus excluding the possibility of identifying patients with de novo risk (patients without a history of disease), which represents most women. In this setting, previous studies have underlined the potential contribution of non-coding RNAs (ncRNAs) to detect patients at risk of PRC. However, placenta biopsies or cord blood samples are required, which are not simple procedures. Our review explores the potential of ncRNAs in biofluids (fluids that are excreted, secreted, or developed because of a physiological or pathological process) as biomarkers for identifying patients with low-risk pregnancies. Beyond the regulatory roles of ncRNAs in placental development and vascular remodeling, we investigated their specific expressions in biofluids to determine favorable pregnancy outcomes as well as the most frequent pathologies of pregnant women. We report distinct ncRNA panels associated with PRC based on omics technologies and subsequently define patients at low risk. We present a comprehensive analysis of ncRNA expression in biofluids, including those using next-generation sequencing, shedding light on their predictive value in clinical practice. In conclusion, this paper underscores the emerging significance of ncRNAs in biofluids as promising biomarkers for risk stratification in PRC. The investigation of ncRNA expression patterns and their potential clinical applications is of diagnostic, prognostic, and theragnostic value and paves the way for innovative approaches to improve prenatal care and maternal and fetal outcomes.

Circ_0027885 sponges miR-203-3p to regulate RUNX2 expression and alleviates osteoporosis progression

BACKGROUND

Osteoporosis (OP) is a progressive metabolic disorder that is difficult to cure clinically. The molecular mechanisms of OP urgently need to be further examined. This study was designed to explore the potential function of circ_0027885 during osteogenic differentiation, as well as the systematic interactions among circ_0027885, miR-203-3p and runt-related transcription factor 2 (RUNX2).

METHODS

Relative levels of circ_0027885, miR-203-3p and RUNX2 were analyzed with RT-qPCR and western blotting. Alizarin red staining was performed to detect the mineralization ability under the control of circ_0027885 and miR-203-3p. Dual-luciferase reporter gene assay was conducted to examine the combination among circ_0027885, miR-203-3p and RUNX2.

RESULTS

Our research demonstrated that circ_0027885 was significantly increased during hBMSCs differentiation. Overexpression of circ_0027885 notably facilitated osteogenic differentiation and upregulated RUNX2 expression, while knockdown of circ_0027885 reversed the above results. Through prediction on bioinformatics analysis, miR-203-3p was the target binding circ_0027885, and RUNX2 was the potential target of miR-203-3p. Subsequently, these changes induced by the overexpression of circ_0027885 were reversed upon addition of miR-203-3p mimic.

CONCLUSIONS

Circ_0027885 could sponge miR-203-3p to regulate RUNX2 expression and alleviate osteoporosis progression.

Clinical Value of Circ-PNPT1 on Adverse Pregnancy Outcomes of Patients with Gestational Diabetes Mellitus

OBJECTIVE

Several circular RNAs are associated with important pathophysiological characteristics of gestational diabetes mellitus (GDM). This study intended to measure the expression of circ-PNPT1 in sera of GDM patients and to expound on its values on pregnancy outcomes.

METHODS

Totally 104 GDM patients and 71 healthy controls were recruited. The expression pattern of serum circ-PNPT1 was measured by reverse transcription-quantitative polymerase chain reaction. The diagnostic efficacy of circ-PNPT1 and fasting blood glucose (FBG) on GDM was evaluated by receiver operating characteristic (ROC) analysis. Parameters of glycolipid metabolism were determined using automatic biochemical analyzers. The correlation between circ-PNPT1 and glycolipid metabolism parameters was analyzed using Pearson analysis. GDM patients were divided into a high expression group and a low expression group based on the median value of circ-PNPT1 expression. Curves of adverse neonatal outcomes were drawn by Log Rank analysis.

RESULTS

GDM patients exhibited higher circ-PNPT1 expression than healthy controls. The area under the ROC curve of circ-PNPT1 diagnosing GDM was 0.9184 and the cut-off value was 1.435 (90.38% sensitivity, 85.92% specificity). Serum circ-PNPT1 expression was positively correlated with FBG, total cholesterol, and triglyceride in GDM patients. Neonates born to GDM patients with high circ- PNPT1 expression were prone to adverse outcomes.

CONCLUSION

Circ-PNPT1 was highly-expressed in the sera of GDM patients. Circ-PNPT1 affected glycolipid metabolism and its expression had certain reference values on adverse pregnancy outcomes.

Molecular mechanisms of noncoding RNA and epigenetic regulation in obesity with consequent diabetes mellitus development

Diabetes mellitus (DM) and obesity have become two of the most prevalent and challenging diseases worldwide, with increasing incidence and serious complications. Recent studies have shown that noncoding RNA (ncRNA) and epigenetic regulation play crucial roles in the pathogenesis of DM complicated by obesity. Identification of the involvement of ncRNA and epigenetic regulation in the pathogenesis of diabetes with obesity has opened new avenues of investigation. Targeting these mechanisms with small molecules or RNA-based therapies may provide a more precise and effective approach to diabetes treatment than traditional therapies. In this review, we discuss the molecular mechanisms of ncRNA and epigenetic regulation and their potential therapeutic targets, and the research prospects for DM complicated with obesity.