Urinary Exosomal microRNA-21 as a Marker for Scrub Typhus-Associated Acute Kidney Injury

Circulating microRNAs as markers for scrub typhus-associated acute kidney injury

BACKGROUND

Circulating microRNAs (miRNAs) are potential biomarkers for various kidney diseases. In this study, we aimed to identify a circulating miRNA signature for detecting acute kidney injury (AKI) in scrub typhus.

METHODS

We prospectively enrolled 40 patients with scrub typhus (20 with AKI, AKI group; 20 without AKI, non-AKI group) and 20 healthy volunteers (the HV group). Thereafter, we performed microarray analysis to assess the serum miRNA profiles of all the participants. Then, to identify miRNAs predictive of scrub typhus-associated AKI, we compared miRNA profiles among these three groups.

RESULTS

The proportions of miRNAs, small nucleolar RNAs, and small Cajal body-specific ribonucleoproteins were higher in patients with scrub typhus than in the HVs. Further, relative to the HVs, we identified 120 upregulated and 449 downregulated miRNAs in the non-AKI group and 101 upregulated and 468 downregulated miRNAs in the AKI group. We also identified 11 and 110 upregulated and downregulated miRNAs, respectively, in the AKI group relative to the non-AKI group, and among these miRNAs, we noted 14 miRNAs whose levels were significantly upregulated or downregulated in the AKI group relative to their levels in the HV and non-AKI groups. Biological pathway analysis of these 14 miRNAs indicated their potential involvement in various pathways associated with tumor necrosis factor alpha.

CONCLUSION

We identified miRNAs associated with AKI in patients with scrub typhus that have predictive potential for AKI. Thus, they can be used as surrogate markers for the detection of scrub typhus-associated AKI.

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

Association between expression levels of p53, miRNA-21, and lncRNA-TCL6 and the risk of preeclampsia in pregnant women

BACKGROUND

Preeclampsia is a hypertensive pregnancy-related disorder. The etiology of preeclampsia is still not fully elucidated. Genetic factors are suggested to play a vital role.

AIM

The association between p53, miRNA-21, and lncRNA-TCL6 expression levels and the risk of preeclampsia and its onset and severity in pregnant women was evaluated.

METHOD

Expression levels of the analyzed RNAs were assessed in the serum samples from 75 preeclamptic pregnant women and 75 volunteer pregnant women with an uncomplicated pregnancy.

RESULTS

Cases showed upregulated p53, lnc-TCL6, and downregulated miRNA-21. P53 expression and preeclampsia severity were substantially correlated, while miRNA-21 and lnc-TCL6 were not. None of them was associated with preeclampsia onset. In diagnosing preeclampsia, p53 had the best sensitivity (98.67 %), followed by miRNA-21 (97.33 %) and lnc-TCL6 (92 %). P53 had the highest sensitivity (68.42 %) for distinguishing mild from severe cases. Lnc-TCL6 exhibited 52.63 % sensitivity, while miRNA-21 had 52.63 % sensitivity. Finally, for discriminating early and late-onset cases, miRNA-21 demonstrated the highest sensitivity (66 %), followed by p53 (62 %) and lnc-TCL6 (54 %). P53 expression was inversely correlated with proteinuria. Parity, TLC, platelet count, AST, and ALT were positively correlated, while lnc-TCL6 expression was negatively correlated with miRNA-21 expression. However, parity negatively correlated with lnc-TCL6 expression.

CONCLUSION

P53, miRNA-21, and lnc-TCL6 were dysregulated in preeclampsia compared to normal pregnancy, highlighting the role of apoptosis in its development. P53 can be a prognostic marker for preeclampsia, discriminating between mild and severe cases.

Exosomes Highlight Future Directions in the Treatment of Acute Kidney Injury

Acute kidney injury (AKI) is a severe health problem associated with high morbidity and mortality rates. It currently lacks specific therapeutic strategies. This review focuses on the mechanisms underlying the actions of exosomes derived from different cell sources, including red blood cells, macrophages, monocytes, mesenchymal stem cells, and renal tubular cells, in AKI. We also investigate the effects of various exosome contents (such as miRNA, lncRNA, circRNA, mRNA, and proteins) in promoting renal tubular cell regeneration and angiogenesis, regulating autophagy, suppressing inflammatory responses and oxidative stress, and preventing fibrosis to facilitate AKI repair. Moreover, we highlight the interactions between macrophages and renal tubular cells through exosomes, which contribute to the progression of AKI. Additionally, exosomes and their contents show promise as potential biomarkers for diagnosing AKI. The engineering of exosomes has improved their clinical potential by enhancing isolation and enrichment, target delivery to injured renal tissues, and incorporating small molecular modifications for clinical use. However, further research is needed to better understand the specific mechanisms underlying exosome actions, their delivery pathways to renal tubular cells, and the application of multi-omics research in studying AKI.

The role of small extracellular vesicle non-coding RNAs in kidney diseases

Kidney diseases have become an increasingly common public health concern worldwide. The discovery of specific biomarkers is of substantial clinical significance in kidney disease diagnosis, therapy and prognosis. The small extracellular vesicle (sEV) can be secreted by several cell types, like renal tubular epithelial cells, podocytes, collecting duct cells and leap cells, and functions as a communication medium between cells by delivering signaling molecules, including proteins, lipids and nucleic acids. There has been growing evidence that kidney diseases are associated with aberrant expression of sEV-derived non-coding RNAs (sEV-ncRNAs). As a result, sEV-ncRNAs may provide valuable information about kidney diseases. In this paper, a systematic review is presented of what has been done in recent years regarding sEV-ncRNAs in kidney disease diagnosis, treatment and prognosis.

The clinical significance of circulating microRNA-21 in patients with IgA nephropathy

Background: Urinary microRNA-21 (miR-21) has been reported to correlate with the histologic lesions of IgA nephropathy (IgAN). We investigated whether urinary or circulating miR-21 could serve as a biomarker for detecting the renal progression of IgAN.Methods: Forty patients with biopsy-proven IgAN were enrolled in this study. Serum and urinary sediment miRs were extracted, and the expression of miR-21 was quantified by real-time quantitative polymerase chain reaction. Renal progression was defined as end-stage renal disease, a sustained doubling of serum creatinine, or a 50% decrease in estimated glomerular filtration rate (eGFR) from baseline.Results: Six patients experienced renal progression during the follow-up period. The baseline eGFR was lower in the progression group (49±11 mL/min/1.73 m2 vs. 90±23 mL/min/1.73 m2, p<0.05) than in the non-progression group. The level of circulating miR-21 on kidney biopsy was higher in the progression group than in the non-progression group (40.0±0.6 vs. 38.2±1.1 ΔCt value of miR-21, p<0.01), whereas there was no significant difference in urinary miR-21 (38.1±2.1 vs. 37.8±1.4 ΔCt value of miR-21, p=0.687) between the two groups. Receiver operating characteristic curve analysis demonstrated that circulating miR-21 had good discriminative power for diagnosing renal progression of IgAN, with an area under the curve of 0.975.Conclusions: The level of circulating miR-21 was higher in the progression group than in the non-progression group at the time of kidney biopsy. Therefore, circulating miR-21 could be a surrogate marker of renal progression in patients with IgAN.

What do we actually know about exosomal microRNAs in kidney diseases?

There are several types of kidney diseases with complex causes. If left untreated, these diseases irreversibly progress to end-stage renal disease. Thus, their early diagnosis and targeted treatment are important. Exosomes-extracellular vesicles released by a variety of cells-are ideal carriers for DNA, RNA, proteins, and other metabolites owing to their bilayer membranes. Studies have shown that almost all renal cells can secrete exosomes. While research on exosomal microRNAs in the context of renal diseases begun only recently, rapid progress has been achieved. This review summarizes the changes in exosomal microRNA expression in different kidney diseases. Thus, it highlights the diagnostic and prognostic value of these exosomal microRNAs. Further, this review analyzes their roles in the development of different kidney diseases, guiding research on molecular mechanisms and therapeutic strategies.

Urinary exosomes: Emerging therapy delivery tools and biomarkers for urinary system diseases

Urinary exosomes (UE) are small circular membranous vesicles with a lipid bilayer with a diameter of 40-160 nm secreted by epithelial cells of the kidney and genitourinary system, which can reflect the physiological and functional status of secretory cells. Protein and RNA in exosomes can be used as markers for diseases diagnosis. Urine specimens are available and non-invasive. The protein and RNA in UE are more stable than the soluble protein and RNA in urine, which have broad application prospects in the diagnosis of urinary system diseases. This article reviews the recent advances in the application of protein or RNA in UE as markers to the diagnosis of urinary system diseases.

Circulating miRNAs in extracellular vesicles related to treatment response in patients with idiopathic membranous nephropathy

Background

Extracellular vesicle (EV)-microRNAs (miRNAs) are potential biomarkers for various renal diseases. This study attempted to identify the circulating EV-miRNA signature not only for discriminating idiopathic membranous nephropathy (IMN) from idiopathic nephrotic syndrome (INS), but also to predict the treatment response of patients with IMN.

Methods

We prospectively enrolled 60 participants, including those with IMN (n = 19) and INS (n = 21) and healthy volunteers (HVs; n = 20) in this study. Using RNA sequencing, we assessed the serum EV-miRNA profiles of all participants. To identify the EV-miRNAs predictive of treatment response in IMN, we also analyzed EV-miRNAs among patients with IMN with and without clinical remission.

Results

The expression levels of 3 miRNAs differed between IMN patients, INS patients and HVs. In addition, compared to HVs, RNA sequencing revealed differential expression of 77 and 44 EV-miRNAs in patients with IMN without and with remission, respectively. We also identified statistically significant (|fold change ≥ 2, p < 0.05) differences in the expression levels of 23 miRNAs in IMN without remission. Biological pathway analysis of miRNAs in IMN without remission indicated that they are likely involved in various pathways, including renal fibrosis.

Conclusion

Our study identified EV-miRNAs associated with IMN as well as those associations with therapeutic response. Therefore, these circulating EV-miRNAs may be used as potential markers for the diagnosis and prediction of treatment response in patients with IMN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03430-7.

TP53-mediated miR-2861 promotes osteogenic differentiation of BMSCs by targeting Smad7

Bone defect seriously affects the quality of life. Meanwhile, osteogenic differentiation in BMSCs could regulate the progression of bone defect. Transcription factors are known to regulate the osteogenic differentiation in BMSCs. The study aimed to investigate the detailed mechanism by which TP53 regulates the osteogenic differentiation. To study bone defect in vitro, BMSCs were isolated from spinal cord injury rats. CCK-8 assay was applied to test the cell viability. The mineralized nodules in BMSCs was tested by alizarin red staining. Meanwhile, TUNEL staining and flow cytometry were performed to test the cell apoptosis. mRNA expression was tested by qRT-PCR. Starbase and dual-luciferase reporter assay were used to predict the downstream mRNA of miR-2861. Moreover, western blot was applied to detect the protein expressions (TP53 and Smad7). BMSCs were successfully isolated from rats. The expressions of miR-2861 were significantly upregulated in osteogenic medium, compared with growth medium. MiR-2861 inhibitor significantly decreased the levels of OCN, ALP, BSP, and Runx2 in BMSCs. In addition, miR-2861 inhibitor notably inhibited the mineralized nodules, viability, and induced the apoptosis of BMSCs. Smad7 was identified to be the downstream target of miR-2861, and knockdown of Smad7 notably reversed miR-2861 inhibitor-induced inhibition of osteogenic differentiation and promotion of apoptosis in BMSCs. Moreover, miR-2861 was transcriptionally regulated by TP53 in BMSCs. TP53-meidiated miR-2861 promotes osteogenic differentiation of BMSCs by targeting Smad7. Thereby, our research might provide new methods for bone defect treatment.