Exosomal MicroRNA-10a Is Associated with Liver Regeneration in Rats through Downregulation of EphA4

Transcriptomic analyses of ovarian clear-cell carcinoma with concurrent endometriosis

Introduction

Endometriosis, a benign inflammatory disease whereby endometrial-like tissue grows outside the uterus, is a risk factor for endometriosis-associated ovarian cancers. In particular, ovarian endometriomas, cystic lesions of deeply invasive endometriosis, are considered the precursor lesion for ovarian clear-cell carcinoma (OCCC).

Methods

To explore this transcriptomic landscape, OCCC from women with pathology-proven concurrent endometriosis (n = 4) were compared to benign endometriomas (n = 4) by bulk RNA and small-RNA sequencing.

Results

Analysis of protein-coding genes identified 2449 upregulated and 3131 downregulated protein-coding genes (DESeq2, P< 0.05, log2 fold-change > |1|) in OCCC with concurrent endometriosis compared to endometriomas. Gene set enrichment analysis showed upregulation of pathways involved in cell cycle regulation and DNA replication and downregulation of pathways involved in cytokine receptor signaling and matrisome. Comparison of pathway activation scores between the clinical samples and publicly-available datasets for OCCC cell lines revealed significant molecular similarities between OCCC with concurrent endometriosis and OVTOKO, OVISE, RMG1, OVMANA, TOV21G, IGROV1, and JHOC5 cell lines. Analysis of miRNAs revealed 64 upregulated and 61 downregulated mature miRNA molecules (DESeq2, P< 0.05, log2 fold-change > |1|). MiR-10a-5p represented over 21% of the miRNA molecules in OCCC with endometriosis and was significantly upregulated (NGS: log2fold change = 4.37, P = 2.43e-18; QPCR: 8.1-fold change, P< 0.05). Correlation between miR-10a expression level in OCCC cell lines and IC50 (50% inhibitory concentration) of carboplatin in vitro revealed a positive correlation (R2 = 0.93). MiR-10a overexpression in vitro resulted in a significant decrease in proliferation (n = 6; P< 0.05) compared to transfection with a non-targeting control miRNA. Similarly, the cell-cycle analysis revealed a significant shift in cells from S and G2 to G1 (n = 6; P< 0.0001). Bioinformatic analysis predicted that miR-10a-5p target genes that were downregulated in OCCC with endometriosis were involved in receptor signaling pathways, proliferation, and cell cycle progression. MiR-10a overexpression in vitro was correlated with decreased expression of predicted miR-10a target genes critical for proliferation, cell-cycle regulation, and cell survival including [SERPINE1 (3-fold downregulated; P< 0.05), CDK6 (2.4-fold downregulated; P< 0.05), and RAP2A (2-3-fold downregulated; P< 0.05)].

Discussion

These studies in OCCC suggest that miR-10a-5p is an impactful, potentially oncogenic molecule, which warrants further studies.

Role of Bile-Derived Extracellular Vesicles in Hepatocellular Proliferation after Partial Hepatectomy in Rats

Although liver regeneration has been extensively studied, the effects of bile-derived extracellular vesicles (bile EVs) on hepatocytes has not been elucidated. We examined the influence of bile EVs, collected from a rat model of 70% partial hepatectomy (PH), on hepatocytes. We produced bile-duct-cannulated rats. Bile was collected over time through an extracorporeal bile duct cannulation tube. Bile EVs were extracted via size exclusion chromatography. The number of EVs released into the bile per liver weight 12 h after PH significantly increased. Bile EVs collected 12 and 24 h post-PH, and after sham surgery (PH12-EVs, PH24-EVs, sham-EVs) were added to the rat hepatocyte cell line, and 24 h later, RNA was extracted and transcriptome analysis performed. The analysis revealed that more upregulated/downregulated genes were observed in the group with PH24-EVs. Moreover, the gene ontology (GO) analysis focusing on the cell cycle revealed an upregulation of 28 types of genes in the PH-24 group, including genes that promote cell cycle progression, compared to the sham group. PH24-EVs induced hepatocyte proliferation in a dose-dependent manner in vitro, whereas sham-Evs showed no significant difference compared to the controls. This study revealed that post-PH bile Evs promote the proliferation of the hepatocytes, and genes promoting cell cycles are upregulated in hepatocytes.

Clinical implications of exosome-derived noncoding RNAs in liver

Exosomes, one of three main types of extracellular vesicles, are ~30-100 nm in diameter and have a lipid bilayer membrane. They are widely distributed in almost all body fluids. Exosomes have the potential to regulate unknown cellular and molecular mechanisms in intercellular communication, organ homeostasis, and diseases. They are critical signal carriers that transfer nucleic acids, proteins, lipids, and other substances into recipient cells, participating in cellular signal transduction and material exchange. ncRNAs are non-protein-coding genes that account for over 90% of the genome and include microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). ncRNAs are crucial for physiological and pathological activities in the liver by participating in gene transcription, posttranscriptional epigenetic regulation, and cellular processes through interacting with DNA, RNA, or proteins. Recent evidence from both clinical and preclinical studies indicates that exosome-derived noncoding RNAs (ncRNAs) are highly involved in the progression of acute and chronic liver diseases by regulating hepatic lipid metabolism, innate immunity, viral infection, fibrosis, and cancer. Therefore, exosome-derived ncRNAs have promising potential and clinical implications for the early diagnosis, targeted therapy, and prognosis of liver diseases.

Mesenchymal Stem Cell-Derived Exosomes: Toward Cell-Free Therapeutic Strategies in Chronic Kidney Disease

Chronic kidney disease (CKD) is rising in global prevalence and has become a worldwide public health problem, with adverse outcomes of kidney failure, cardiovascular disease, and premature death. However, current treatments are limited to slowing rather than reversing disease progression or restoring functional nephrons. Hence, innovative strategies aimed at kidney tissue recovery hold promise for CKD therapy. Mesenchymal stem cells (MSCs) are commonly used for regenerative therapy due to their potential for proliferation, differentiation, and immunomodulation. Accumulating evidence suggests that the therapeutic effects of MSCs are largely mediated by paracrine secretion of extracellular vesicles (EVs), predominantly exosomes. MSC-derived exosomes (MSC-Exos) replicate the functions of their originator MSCs via delivery of various genetic and protein cargos to target cells. More recently, MSC-Exos have also been utilized as natural carriers for targeted drug delivery. Therapeutics can be effectively incorporated into exosomes and then delivered to diseased tissue. Thus, MSC-Exos have emerged as a promising cell-free therapy in CKD. In this paper, we describe the characteristics of MSC-Exos and summarize their therapeutic efficacy in preclinical animal models of CKD. We also discuss the potential challenges and strategies in the use of MSC-Exos-based therapies for CKD in the future.

MicroRNA-34c promotes neuronal recovery in rats with spinal cord injury through the C-X-C motif ligand 14/Janus kinase 2/signal transducer and activator of transcription-3 axis

Supplemental Digital Content is available in the text

Background

Developing effective spinal cord repair strategies for spinal cord injury (SCI) is of great importance. Emerging evidence suggests that microRNAs (miRNAs) are closely linked to SCI recovery. This study aimed to investigate the function of miR-34c in the neuronal recovery in rats with SCI.

Methods

A rat model with SCI was established. Differentially expressed miRNAs were identified by a microarray analysis. MiR-34c expression in rats was measured by reverse transcription quantitative polymerase chain reaction. Altered expression of miR-34c or C-X-C motif ligand 14 (CXCL14) was introduced in SCI rats to measure their roles in neuronal recovery. Western blot analysis was performed to determine the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription-3 (STAT3). Neuronal apoptosis in rat spinal cord tissues was detected. The concentrations of SCI recovery-related proteins thyrotropin releasing hormone (TRH), prostacyclin (PGI2), and ganglioside (GM) were evaluated by enzyme-linked immunosorbent assay. Data were analyzed using a t-test with a one-way or two-way analysis of variance.

Results

Rats with SCI presented decreased grip strength (112.03 ± 10.64 vs. 17.32 ± 1.49 g, P < 0.01), decreased miR-34c expression (7 days: 3.78 ± 0.44 vs. 0.95 ± 0.10, P < 0.05), and increased CXCL14 expression (7 days: 0.61 ± 0.06 vs. 2.91 ± 0.27, P < 0.01). MiR-34c was found to directly bind to CXCL14. Overexpression of miR-34c increased grip strength (11.23 ± 1.08 vs. 31.26 ± 2.99 g, P < 0.01) and reduced neuronal apoptosis in spinal cord tissues (53.61% ± 6.07% vs. 24.59% ± 3.32%, P < 0.01), and silencing of CXCL14 also increased the grip strength (12.76 ± 1.13 vs. 29.77 ± 2.75 g, P < 0.01) and reduced apoptosis in spinal cord tissues (55.74% ± 6.24% vs. 26.75% ± 2.84%, P < 0.01). In addition, miR-34c upregulation or CXCL14 downregulation increased the concentrations of TRH, PGI2, and GM, and reduced phosphorylation of JAK2 and STAT3 in rats with SCI (all P < 0.01).

Conclusion

The study provided evidence that miR-34c could promote neuronal recovery in rats with SCI through inhibiting CXCL14 expression and inactivating the JAK2/STAT3 pathway. This study may offer new insights into SCI treatment.

MicroRNA-125a-3p overexpression promotes liver regeneration through targeting proline-rich acidic protein 1

INTRODUCTION AND OBJECTIVES

Liver regeneration plays a valuable significance for hepatectomies, and is mainly attributed to hepatocyte proliferation. MicroRNA-125a-3p was reported to be highly associated with liver regeneration process. We studied the underlying mechanism of the functional role of miR-125a-3p in liver regeneration.

MATERIALS AND METHODS

The miR-125a-3p mimics and inhibitor vector were constructed and transfected into primary human liver HL-7702 cells, the transfected cell viability was detected using cell counting kit-8 (CCK-8). Cell cycle distribution was analyzed by flow cytometry. With Targetscan and OUGene prediction, the potential targets of miR-125 were verified by real-time quantitative PCR (qPCR) and luciferase reporter assays in turn. The overexpression vector of proline-rich acidic protein 1 (PRAP1) was constructed and co-transfected with miR-125a-3p mimics into HL-7702 cells, detecting the changes of proliferative capacity and cell cycle distribution. Western blot and qPCR performed to analyze gene expressions.

RESULTS

Overexpressed miR-125a-3p notably increased the hepatocyte viability at 48h, and decreased the number of G1 phase cells (p<0.05). However, miR-125a-3p inhibition suppressed the development of hepatocytes. PRAP1 was the target of miR-125a-3p. After co-transfection with PRAP1 vector, hepatocyte viability was decrease and the G1 phase cell number was increased (p<0.05). More importantly, overexpressed PRAP1 notably decreased the mRNA and protein levels of cyclin D1, cyclin-dependent kinase 2 (CDK2) and cell division cycle 25A (CDC25A).

CONCLUSION

The elevated miR-125a-3p positively correlated with hepatocyte viability and cell cycle progression due to the modulation of PRAP1, and miR-125a-3p may contribute to improving liver regeneration.

Cell Sources and Influencing Factors of Liver Regeneration: A Review

Liver regeneration (LR) is a set of complicated mechanisms between cells and molecules in which the processes of initiation, maintenance, and termination of liver repair are regulated. Although LR has been studied extensively, there are still numerous challenges in gaining its full understanding. Cells for LR have a wide range of sources and the feature of plasticity, and regeneration patterns are not the same under different conditions. Many patients undergoing partial hepatectomy develop cirrhosis or steatosis. The changes of LR in these cases are not clear. Many types of cells participate in LR. Hepatocytes, biliary epithelial cells, hepatic progenitor cells, and human liver stem cells can serve as the cell sources for LR. However, different types and degrees of damage trigger the response from the most suitable cells. Exploring the cell sources of LR is of great significance for accelerating recovery of liver function under different pathological patterns and developing a cell therapy strategy to cope with the shortage of donors for liver transplantation. In clinical practice, the background of the liver influences regeneration. Fibrosis and steatosis create different LR microenvironments and signal molecule interaction patterns. In addition, factors such as partial hepatectomy, aging, platelets, nerves, hormones, bile acids, and gut microbiota are widely involved in this process. Understanding the influencing factors of LR has practical value for individualized treatment of patients with liver diseases. In this review, we have summarized recent studies and proposed our views. We discuss cell sources and the influential factors on LR to help in solving clinical problems.

hUCB-MSC derived exosomal miR-124 promotes rat liver regeneration after partial hepatectomy via downregulating Foxg1

Liver regeneration after partial hepatectomy (PH) is a complex and well-orchestrated process involving multiple factors such as cytokines, growth factors, and signaling pathways. MicroRNAs (miRNAs) participate in various biological processes including liver regeneration after PH. In the current study, we investigated the expression and function of human umbilical cord blood mesenchymal stem cell (hUCB-MSC) derived exosomal miRNAs on liver regeneration using a rat PH model. We found that hUCB-MSC derived exosomes promoted rat liver regeneration and ameliorated liver injury after PH. MicroRNA microarray was performed to identify the differentially expressed miRNAs in hUCB-MSC derived exosomes involving in liver regeneration after PH. We demonstrated that hUCB-MSC derived exosomal miR-124 could promote liver regeneration and prevent against liver injury after PH in rats. Inhibition of miR-124 abrogated the protective role of hUCB-MSC derived exosome in rat liver regeneration after PH. In addition, we identified that transcription factor Foxg1 was a direct target of miR-124 and miR-124 promoted rat liver cell proliferation via suppressing Foxg1 expression. Furthermore, we demonstrated that hUCB-MSC derived exosomal miR-124 enhanced liver regeneration via inhibiting Foxg1 in rats after PH. In summary, our findings suggest that hUCB-MSC-derived exosomal miR-124 could promote rat liver regeneration after PH via downregulating Foxg1.

Approaches to Manipulate Ephrin-A:EphA Forward Signaling Pathway

Erythropoietin-producing hepatocellular carcinoma A (EphA) receptors and their ephrin-A ligands are key players of developmental events shaping the mature organism. Their expression is mostly restricted to stem cell niches in adults but is reactivated in pathological conditions including lesions in the heart, lung, or nervous system. They are also often misregulated in tumors. A wide range of molecular tools enabling the manipulation of the ephrin-A:EphA system are available, ranging from small molecules to peptides and genetically-encoded strategies. Their mechanism is either direct, targeting EphA receptors, or indirect through the modification of intracellular downstream pathways. Approaches enabling manipulation of ephrin-A:EphA forward signaling for the dissection of its signaling cascade, the investigation of its physiological roles or the development of therapeutic strategies are summarized here.

Inhibition of miR-10a-5p suppresses cholangiocarcinoma cell growth through downregulation of Akt pathway

Backgrounds

Cholangiocarcinoma (CCA) is epithelial cell malignancy with very poor prognosis. A lot of patients were diagnosed at advanced stage of CCA and no risk factors were identified. There are limited treatment options available for the management of CCA patients. It is urgent to develop effective targeted therapies for the treatment of CCA. miRNAs are small noncoding RNAs that negatively regulate the target genes. In this study, we investigated the role and mechanism of miR-10a-5p in CCA.

Methods

Human CCA cell lines (CCLP1 and SG-231) were transfected with miR-10a-5p mimic or miR-10a-5p inhibitor. qRT-PCR was performed to detect the miR-10a-5p level. Proliferation, colony formation, and apoptosis were analyzed. Luciferase reporter assay was used to explore the targeting of miR-10a-5p on PTEN. For in vivo tumorigenesis assay, CCLP1 cells with stable knockdown of miR-10a-5p or control CCLP1 cells were injected subcutaneously into the flank of the SCID mice and animals were monitored for tumor growth.

Results

miR-10a-5p expression was significantly upregulated in human CCA cell lines (CCLP1 and SG-231). Inhibition of miR-10a-5p significantly suppressed the proliferation and induced apoptosis in CCLP1 and SG-231. PTEN is a direct target of miR-10a-5p in CCA cells.

Conclusion

Inhibition of miR-10a-5p can decrease CCA cells growth by downregulation of Akt pathway. These results indicate that miR-10a-5p may serve as a potential target for the treatment of CCA and help to develop effective therapeutic strategies.