Long Non-Coding RNA MALAT1 Promotes Proliferation, Angiogenesis, and Immunosuppressive Properties of Mesenchymal Stem Cells by Inducing VEGF and IDO

Silencing the long noncoding RNA MALAT1 inhibits vitreous-induced epithelial-mesenchymal transition in RPE cells by regulating the PDGFRs/AKT axis

PURPOSE

Epithelial-mesenchymal transition (EMT) is a crucial pathological process that contributes to proliferative vitreoretinopathy (PVR), and research indicates that factors present in the vitreous that target cells play pivotal roles in regulating EMT. Experimental studies have confirmed that rabbit vitreous (RV) promotes EMT in human retinal pigment epithelial (RPE) cells. The long noncoding RNA (lncRNA) MALAT1 has been implicated in EMT in various diseases. Thus, this study aimed to investigate the involvement of lncRNA MALAT1 in vitreous-induced EMT in RPE cells.

METHODS

MALAT1 was knocked down in ARPE-19 cells by short hairpin RNA (shRNA) transfection. Reverse transcription PCR (RT‒PCR) was used to evaluate MALAT1 expression, and Western blotting analysis was used to measure the expression of EMT-related proteins. Wound-healing, Transwell, and cell contraction assays were conducted to assess cell migration, invasion, and contraction, respectively. Additionally, cell proliferation was assessed using the CCK-8 assay, and cytoskeletal changes were examined by immunofluorescence.

RESULTS

MALAT1 expression was significantly increased in ARPE-19 cells cultured with RV. Silencing MALAT1 effectively suppressed EMT and downregulated the associated factors snail1 and E-cadherin. Furthermore, silencing MALAT1 inhibited the RV-induced migration, invasion, proliferation, and contraction of ARPE-19 cells. Silencing MALAT1 also decreased RV-induced AKT and P53 phosphorylation.

CONCLUSIONS

In conclusion, lncRNA MALAT1 participates in regulating vitreous-induced EMT in human RPE cells; these results provide new insight into the pathogenesis of PVR and offer a potential direction for the development of antiproliferative drugs.

MIR193BHG inhibits the proliferation, migration and invasion of trophoblasts by upregulating p53

Aberrant expression of long non-coding RNAs (lncRNAs) serves a crucial role in the biological function of trophoblasts and contributes to preeclampsia (PE). lncRNA MIR193BHG expression is increased in PE placental tissues. In the present study, the effects of MIR193BHG on the function of trophoblasts were assessed to elucidate its underlying molecular mechanisms. The subcellular localization of MIR193BHG in HTR-8/SVneo human first-trimester extravillous trophoblast cells was determined using a fluorescent in situ hybridization assay and by conducting nucleocytoplasmic separation. The effect of MIR193BHG knockdown or overexpression on proliferation, migration, invasion and apoptosis was evaluated in vitro using Cell Counting Kit-8, wound healing, Transwell and flow cytometry assays. RNA-sequencing, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and protein-protein interaction network construction were subsequently performed to screen the downstream molecules regulated by MIR193BHG. Finally, rescue experiments were conducted to ascertain whether MIR193BHG influenced the biological function of trophoblasts via p53. MIR193BHG was predominantly localized in the nucleus of HTR-8/SVneo cells and overexpression of MIR193BHG significantly inhibited proliferation, migration and invasion, while increasing the rate of apoptosis of HTR-8/SVneo cells. Knockdown of MIR193BHG had the opposite effect. Furthermore, overexpression of MIR193BHG led to increases in both mRNA and protein levels of p53 compared with the control group, and knockdown of p53 rescued the effects induced by overexpression of MIR193BHG on cell proliferation, migration and invasion, while partially counteracting its effects on apoptosis of HTR-8/SVneo cells. In conclusion, the findings of the present study suggested that MIR193BHG served a critical role in progression of PE by regulating the expression of p53, and may be a novel therapeutic target for PE.

Regulation and Therapeutic Application of Long non-Coding RNA in Tumor Angiogenesis

Tumor growth and metastasis rely on angiogenesis. In recent years, long non-coding RNAs have been shown to play an important role in regulating tumor angiogenesis. Here, we review the multidimensional modes and relevant molecular mechanisms of long non-coding RNAs in regulating tumor angiogenesis. In addition, we summarize new strategies for tumor anti-angiogenesis therapies by targeting long non-coding RNAs. The aim of this study is to provide new diagnostic targets and treatment strategies for anti-angiogenic tumor therapy.

Evaluation of long noncoding RNA (LncRNA) in pathogenesis of HELLP syndrome: diagnostic and future approach

HELLP syndrome is a disorder during pregnancy which is defined by elevation of liver enzymes, haemolysis, and low platelet count. This syndrome is a multifactorial one and both genetic and environmental components can have a crucial role in this syndrome's pathogenesis. Long noncoding RNAs (lncRNAs), are defined as long non-protein coding molecules (more than 200 nucleotides), which are functional units in most cellular processes such as cell cycle, differentiation, metabolism and some diseases progression. As these markers discovered, there has been some evidence that they have an important role in the function of some organs, such as placenta; therefore, alteration and dysregulation of these RNAs can develop or alleviate HELLP disorder. Although the role of lncRNAs has been shown in HELLP syndrome, the process is still unclear. In this review, our purpose is to evaluate the association between molecular mechanisms of lncRNAs and HELLP syndrome pathogenicity to elicit some novel approaches for HELLP diagnosis and treatment.

Noninvasive preeclampsia prediction using plasma cell-free RNA signatures

BACKGROUND

Preeclampsia, especially preterm preeclampsia and early-onset preeclampsia, is a life-threating pregnancy disorder, and the heterogeneity and complexity of preeclampsia make it difficult to predict risk and to develop treatments. Plasma cell-free RNA carries unique information from human tissue and may be useful for noninvasive monitoring of maternal, placental, and fetal dynamics during pregnancy.

OBJECTIVE

This study aimed to investigate various RNA biotypes associated with preeclampsia in plasma and to develop classifiers to predict preterm preeclampsia and early-onset preeclampsia before diagnosis.

STUDY DESIGN

We performed a novel, cell-free RNA sequencing method termed polyadenylation ligation-mediated sequencing to investigate the cell-free RNA characteristics of 715 healthy pregnancies and 202 pregnancies affected by preeclampsia before symptom onset. We explored differences in the abundance of different RNA biotypes in plasma between healthy and preeclampsia samples and built preterm preeclampsia and early-onset preeclampsia prediction classifiers using machine learning methods. Furthermore, we validated the performance of the classifiers using the external and internal validation cohorts and assessed the area under the curve and positive predictive value.

RESULTS

We detected 77 genes, including messenger RNA (44%) and microRNA (26%), that were differentially expressed in healthy mothers and mothers with preterm preeclampsia before symptom onset, which could separate participants with preterm preeclampsia from healthy samples and that played critical functional roles in preeclampsia physiology. We developed 2 classifiers for predicting preterm preeclampsia and early-onset preeclampsia before diagnosis based on 13 cell-free RNA signatures and 2 clinical features (in vitro fertilization and mean arterial pressure), respectively. Notably, both classifiers showed enhanced performance when compared with the existing methods. The preterm preeclampsia prediction model achieved 81% area under the curve and 68% positive predictive value in an independent validation cohort (preterm, n=46; control, n=151); the early-onset preeclampsia prediction model had an area under the curve of 88% and a positive predictive value of 73% in an external validation cohort (early-onset preeclampsia, n=28; control, n=234). Furthermore, we demonstrated that downregulation of microRNAs may play vital roles in preeclampsia through the upregulation of preeclampsia-relevant target genes.

CONCLUSION

In this cohort study, a comprehensive transcriptomic landscape of different RNA biotypes in preeclampsia was presented and 2 advanced classifiers with substantial clinical importance for preterm preeclampsia and early-onset preeclampsia prediction before symptom onset were developed. We demonstrated that messenger RNA, microRNA, and long noncoding RNA can simultaneously serve as potential biomarkers of preeclampsia, holding the promise of prevention of preeclampsia in the future. Abnormal cell-free messenger RNA, microRNA, and long noncoding RNA molecular changes may help to elucidate the pathogenic determinants of preeclampsia and open new therapeutic windows to effectively reduce pregnancy complications and fetal morbidity.

Unveiling Mesenchymal Stem Cells' Regenerative Potential in Clinical Applications: Insights in miRNA and lncRNA Implications

It is now widely recognized that mesenchymal stem cells (MSCs) possess the capacity to differentiate into a wide array of cell types. Numerous studies have identified the role of lncRNA in the regulation of MSC differentiation. It is important to elucidate the role and interplay of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the regulation of signalling pathways that govern MSC function. Furthermore, miRNAs and lncRNAs are important clinical for innovative strategies aimed at addressing a wide spectrum of existing and emerging disease. Hence it is important to consider their impact on MSC function and differentiation. Examining the data available in public databases, we have collected the literature containing the latest discoveries pertaining to human stem cells and their potential in both fundamental research and clinical applications. Furthermore, we have compiled completed clinical studies that revolve around the application of MSCs, shedding light on the opportunities presented by harnessing the regulatory potential of miRNAs and lncRNAs. This exploration of the therapeutic possibilities offered by miRNAs and lncRNAs within MSCs unveils exciting prospects for the development of precision therapies and personalized treatment approaches. Ultimately, these advancements promise to augment the efficacy of regenerative strategies and produce positive outcomes for patients. As research in this field continues to evolve, it is imperative to explore and exploit the vast potential of miRNAs and lncRNAs as therapeutic agents. The findings provide a solid basis for ongoing investigations, fuelling the quest to fully unlock the regenerative potential of MSCs.

The Role of ncRNAs in the Immune Dysregulation of Preeclampsia

The main complications causing practically 75% of all maternal deaths are severe bleeding, infections, and high blood pressure during pregnancy (preeclampsia (PE) and eclampsia). The usefulness of ncRNAs as clinical biomarkers has been explored in an extensive range of human diseases including pregnancy-related diseases such as PE. Immunological dysregulation show that the Th1/17:Th2/Treg ratio is "central and causal" to PE. However, there is evidence of the involvement of placenta-expressed miRNAs and lncRNAs in the immunological regulation of crucial processes of placenta development and function during pregnancy. Abnormal expression of these molecules is related to immune physiopathological processes that occur in PE. Therefore, this work aims to describe the importance of miRNAs and lncRNAs in immune dysregulation in PE. Interestingly, multiple ncRNAS are involved in the immune dysregulation of PE participating in type 1 immune response regulation, immune microenvironment regulation in placenta promoting inflammatory factors, trophoblast cell invasion in women with Early-Onset PE (EOPE), placental development, and angiogenesis, promotion of population of M1 and M2, proliferation, invasion, and migration of placental trophoblast cells, and promotion of invasion and autophagy through vias such as PI3K/AKT/mTOR, VEGF/VEGFR1, and TLR9/STAT3.

Corilagin alleviates liver fibrosis in zebrafish and mice by repressing IDO1-mediated M2 macrophage repolarization

BACKGROUND

Liver fibrosis caused by chronic liver injury, eventually develops into liver cirrhosis and hepatocellular carcinoma. Currently, there are no effective drugs to relieve liver fibrosis due to the lack of molecular pathogenesis characteristics. Former research demonstrates that the hepatic immune microenvironment plays a key role in the pathogenesis of liver fibrosis, thus macrophages are important immune cells in the liver. Our previous study has found that IDO1 plays an important role in the liver immune microenvironment. CRG is a gallic acid tannin found in medicinal plants of many ethnicities that protects against inflammation, tumors and chronic liver disease. However, the mechanism of by which CRG mediates the interaction of IDO1 with macrophages during hepatic immune maturation is not clear.

PURPOSE

To investigate the regulatory mechanism of CRG in liver fibrosis and the intrinsic relationship between IDO1 and macrophage differentiation.

METHODS

Zebrafish, RAW264.7 cells and mice were used in the study. IDO1 overexpression and knockdown cell lines were constructed using lentiviral techniques.

RESULTS

We discovered that CRG remarkably reduced the AST and ALT serum levels. Histological examination revealed that CRG ameliorates CCL4-induced liver fibrosis and depressed the expression of α-SMA, Lamimin, Collagen-Ι and fibronectin. Besides, we found that CRG promoted increased MerTK expression on partly macrophages. Interestingly, in vitro, we found that CRG suppressed IDO1 expression and regulated macrophage differentiation by upregulating CD86, CD80 and iNOS, while downregulating CD206, CD163, IL-4 and IL-10 expression. Additionally, we found that CRG could inhibit hepatic stellate cell activation by direct or indirect action.

CONCLUSION

Our findings suggest that CRG alleviates liver fibrosis by mediating IDO1-mediated M2 macrophage repolarization.

Roles of long non-coding RNAs in angiogenesis-related diseases: Focusing on non-neoplastic aspects

Angiogenesis is a key process in organ and tissue morphogenesis, as well as growth during human development, and is coordinated by pro- and anti-angiogenic factors. When this balance is affected, the related physiological and pathological changes lead to disease. Long non-coding RNAs (lncRNAs) are an important class of non-coding RNAs that do not encode proteins, but play a dynamic role in regulating gene expression. LncRNAs have been reported to be extensively involved in angiogenesis, particularly tumor angiogenesis. The non-tumor aspects have received relatively little attention and summary, but there is a broad space for research and exploration on lncRNA-targeted angiogenesis in this area. In this review, we focus on lncRNAs in angiogenesis-related diseases other than tumors, such as atherosclerosis, myocardial infarction, stroke, diabetic complications, hypertension, osteoporosis, dermatosis, as well as, endocrine, neurological, and other systemic disorders. Moreover, multiple cell types have been implicated in lncRNA-targeted angiogenesis, but only endothelial cells have attracted widespread attention. Thus, we explore the roles of other cells. Finally, we summarize the potential research directions in the area of lncRNAs and angiogenesis that can be undertaken by combining cutting-edge technology and interdisciplinary research, which will provide new insights into the involvement of lncRNAs in angiogenesis-related diseases.

Research progress on the regulation of bone marrow stem cells by noncoding RNAs in adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity in young women, but its pathogenesis remains unclear. The primary pathogenic factors contributing to its development include genetics, abnormal bone metabolism, and endocrine factors. Bone marrow stem cells (BMSCs) play a crucial role in the pathogenesis of AIS by regulating its occurrence and progression. Noncoding RNAs (ncRNAs) are also involved in the pathogenesis of AIS, and their role in regulating BMSCs in patients with AIS requires further evaluation. In this review, we discuss the relevant literature regarding the osteogenic, chondrogenic, and lipogenic differentiation of BMSCs. The corresponding mechanisms of ncRNA-mediated BMSC regulation in patients with AIS, recent advancements in AIS and ncRNA research, and the importance of ncRNA translation profiling and multiomics are highlighted.

Biogenesis and function of exosome lncRNAs and their role in female pathological pregnancy

Preeclampsia, gestational diabetes mellitus, and recurrent spontaneous abortion are common maternal pregnancy complications that seriously endanger women's lives and health, and their occurrence is increasing year after year with a rejuvenation trend. In contrast to biomarkers found freely in tissues or body fluids, exosomes exist in a relatively independent environment and provide a higher level of stability. As backbone molecules, guidance molecules, and signaling molecules in the nucleus, lncRNAs can regulate gene expression. In the cytoplasm, lncRNAs can influence gene expression levels by modifying mRNA stability, acting as competitive endogenous RNAs to bind miRNAs, and so on. Exosomal lncRNAs can exist indefinitely and are important in intercellular communication and signal transduction. Changes in maternal serum exosome lncRNA expression can accurately and timely reflect the progression and regression of pregnancy-related diseases. The purpose of this paper is to provide a reference for clinical research on the pathogenesis, diagnosis, and treatment methods of pregnancy-related diseases by reviewing the role of exosome lncRNAs in female pathological pregnancy and related molecular mechanisms.

Metastasis-associated lung adenocarcinoma transcript 1 induces methyl-CpG-binding domain protein 4 in mice with recurrent spontaneous abortion caused by anti-phospholipid antibody positivity

INTRODUCTION

Antiphospholipid syndrome is an autoimmune disease characterized by pregnancy-related morbidity, related to persistent positivity of antiphospholipid antibodies (APL). One of the characteristics of pregnancy-related morbidity in patients with antiphospholipid syndrome is recurrent spontaneous abortion (RSA). This study aimed to examine the mechanism through which metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) regulates methyl-CpG-binding domain protein 4 (MBD4) expression in APL-positive RSA.

METHODS

Clinical samples were subjected to microarray analysis to filter differentially expressed genes. RSA mice with APL positivity were generated, followed by adenoviral vector injection to artificially upregulate MALAT1. The effects of MALAT1 on the biological behavior of trophoblast cells were assessed. The downstream mechanism of MALAT1 was analyzed using subcellular fractionation and bioinformatics prediction, and the relationship between MALAT1 and CREB binding protein (CREBBP) or MBD4 was investigated in trophoblast cells.

RESULTS

MALAT1 was downregulated in APL-positive RSA patients. MALAT1 was predominantly localized in the nucleus and recruited CREBBP to mediate the MBD4 transcription. In the APL-positive RSA mice overexpressing MALAT1, the expression of soluble Fms-related tyrosine kinase 1 and anticardiolipin antibody and the embryonic resorption rate were decreased, indicating that MALAT1 reduced the occurrence of RSA in mice. Moreover, MALAT1 enhanced proliferation, migration, and invasion of trophoblast cells through recruiting CREBBP to promote MBD4 expression. Silencing of CREBBP or MBD4 increased embryonic resorption rate in RSA mice overexpressing MALAT1.

DISCUSSION

MALAT1 suppresses APL-positive RSA by promoting MBD4 transcription through recruitment of CREBBP to the MBD4 promoter region.

Long Non-Coding RNAs in Hypoxia and Oxidative Stress: Novel Insights Investigating a Piglet Model of Perinatal Asphyxia

Birth asphyxia is the leading cause of death and disability in young children worldwide. Long non-coding RNAs (lncRNAs) may provide novel targets and intervention strategies due to their regulatory potential, as demonstrated in various diseases and conditions. We investigated cardinal lncRNAs involved in oxidative stress, hypoxia, apoptosis, and DNA damage using a piglet model of perinatal asphyxia. A total of 42 newborn piglets were randomized into 4 study arms: (1) hypoxia–normoxic reoxygenation, (2) hypoxia–3 min of hyperoxic reoxygenation, (3) hypoxia–30 min of hyperoxic reoxygenation, and (4) sham-operated controls. The expression of lncRNAs BDNF-AS, H19, MALAT1, ANRIL, TUG1, and PANDA, together with the related target genes VEGFA, BDNF, TP53, HIF1α, and TNFα, was assessed in the cortex, the hippocampus, the white matter, and the cerebellum using qPCR and Droplet Digital PCR. Exposure to hypoxia–reoxygenation significantly altered the transcription levels of BDNF-AS, H19, MALAT1, and ANRIL. BDNF-AS levels were significantly enhanced after both hypoxia and subsequent hyperoxic reoxygenation, 8% and 100% O2, respectively. Our observations suggest an emerging role for lncRNAs as part of the molecular response to hypoxia-induced damages during perinatal asphyxia. A better understanding of the regulatory properties of BDNF-AS and other lncRNAs may reveal novel targets and intervention strategies in the future.

Preeclampsia and the Kidney: Pathophysiology and Clinical Implications

Preeclampsia and other hypertensive disorders of pregnancy are major contributors to maternal morbidity and mortality worldwide. This group of disorders includes chronic hypertension, gestational hypertension, preeclampsia, preeclampsia superimposed on chronic hypertension, and eclampsia. The body undergoes important physiological changes during pregnancy to allow for normal placental and fetal development. Several mechanisms have been proposed that may lead to preeclampsia, including abnormal placentation and placental hypoxia, impaired angiogenesis, excessive pro-inflammatory response, immune system imbalance, abnormalities of cellular senescence, alterations in regulation and activity of angiotensin II, and oxidative stress, ultimately resulting in upregulation of multiple mediators of endothelial cell dysfunction leading to maternal disease. The clinical implications of preeclampsia are significant as there are important short-term and long-term health consequences for those affected. Preeclampsia leads to increased risk of preterm delivery and increased morbidity and mortality of both the developing fetus and mother. Preeclampsia also commonly leads to acute kidney injury, and women who experience preeclampsia or another hypertensive disorder of pregnancy are at increased lifetime risk of chronic kidney disease and cardiovascular disease. An understanding of normal pregnancy physiology and the pathophysiology of preeclampsia is essential to develop novel treatment approaches and manage patients with preeclampsia and hypertensive disorders of pregnancy. © 2023 American Physiological Society. Compr Physiol 13:4231-4267, 2023.

LncRNA MRF drives the regulatory function on monocyte recruitment and polarization through HNRNPD-MCP1 axis in mesenchymal stem cells

Background

Mesenchymal stem cells (MSCs) exhibit two bidirectional immunomodulatory abilities: proinflammatory and anti-inflammatory regulatory effects. Long noncoding RNAs (lncRNAs) have important functions in the immune system. Previously, we performed high-throughput sequencing comparing lncRNA expression profiles between MSCs cocultured with or without CD14+ monocytes and screened out a new lncRNA termed lncRNA MCP1 regulatory factor (MRF). However, the mechanism of MRF in MSCs is still unknown.

Methods

MRF expression was quantified via qRT–PCR. RNA interference and lentiviruses were used to regulate MRF expression. The immunomodulatory effects of MSCs on monocytes were evaluated via monocyte migration and macrophage polarization assays. RNA pull-down and mass spectrometry were utilized to identify downstream factors of MRF. A dual-luciferase reporter assay was applied to analyze the transcription factors regulating MRF. qRT–PCR, western blotting and ELISAs were used to assess MCP1 expression. A human monocyte adoptive transfer mouse model was applied to verify the function of MRF in vivo.

Results

MRF was upregulated in MSCs during coculture with CD14+ monocytes. MRF increased monocyte recruitment by upregulating the expression of monocyte chemotactic protein (MCP1). Knockdown of MRF enhanced the regulatory effect of MSCs on restraining M1 polarization and facilitating M2 polarization. Mechanistically, MRF bound to the downstream protein heterogeneous nuclear ribonucleoprotein D (HNRNPD) to upregulate MCP1 expression, and the transcription factor interferon regulatory factor 1 (IRF1) activated MRF transcription early during coculture. The human monocyte adoptive transfer model showed that MRF downregulation in MSCs inhibited monocyte chemotaxis and enhanced the effects of MSCs to inhibit M1 macrophage polarization and promote M2 polarization in vivo.

Conclusion

We identified the new lncRNA MRF, which exhibits proinflammatory characteristics. MRF regulates the ability of MSCs to accelerate monocyte recruitment and modulate macrophage polarization through the HNRNPD-MCP1 axis and initiates the proinflammatory regulatory process in MSCs, suggesting that MRF is a potential target to improve the clinical effect of MSC-based therapy or correct MSC-related immunomodulatory dysfunction under pathological conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00858-3.

Non-Coding RNAs and Prediction of Preeclampsia in the First Trimester of Pregnancy

Preeclampsia (PE) is a major cause of maternal and perinatal morbidity and mortality. The only fundamental treatment for PE is the termination of pregnancy. Therefore, not only severe maternal complications but also perinatal complications due to immaturity of the infant associated with early delivery are serious issues. The treatment and prevention of preterm onset preeclampsia (POPE) are challenging. In 2017, the ASPRE trial showed that a low oral dose of aspirin administered to POPE high-risk women in early pregnancy reduced POPE by 62%. A prediction algorithm at 11–13 weeks of gestation identifies POPE with 75% sensitivity when the false positive rate is set at 10%. New biomarkers to increase the accuracy of the prediction model for POPE high-risk women in early pregnancy are needed. In this review, we focused on non-coding RNAs (ncRNAs) as potential biomarkers for the prediction of POPE. Highly expressed ncRNAs in the placenta in early pregnancy may play crucial roles in placentation. Furthermore, placenta-specific ncRNAs have been detected in maternal blood. In this review, we summarized ncRNAs that were highly expressed in the primary human placenta in early pregnancy. We also presented highly expressed ncRNAs in the placenta that were associated with or predictive of the development of PE in an expression analysis of maternal blood during the first trimester of pregnancy. These previous studies showed that the chromosome 19 microRNA (miRNA) -derived miRNAs (e.g., miR-517-5p, miR-518b, and miR-520h), the hypoxia-inducible miRNA (miR-210), and long non-coding RNA H19, were not only highly expressed in the early placenta but were also significantly up-regulated in the blood at early gestation in pregnant women who later developed PE. These maternal circulating ncRNAs in early pregnancy are expected to be possible biomarkers for POPE.

The pathological and therapeutic roles of mesenchymal stem cells in preeclampsia

Mesenchymal stem cells (MSCs) have made progress in the treatment of ischemic and inflammatory diseases. Preeclampsia (PE) is characterized by placenta ischemic and inflammatory injury. Our paper summarized the new role of MSCs in PE pathology and its potency in PE therapy and analyzed its current limitations. Intravenously administered MSCs dominantly distributed in perinatal tissues. There may be additional advantages to using MSCs-based therapies for reproductive disorders. It will provide new ideas for future research in this field.

Significance of Placental Mesenchymal Stem Cell in Placenta Development and Implications for Preeclampsia

The well-developed placentation is fundamental for the reproductive pregnancy while the defective placental development is the pathogenetic basis of preeclampsia (PE), a dangerous complication of pregnancy comprising the leading causes of maternal and perinatal morbidity and mortality. Placenta-derived mesenchymal stem cells (PMSCs) are a group of multipotent stem cells that own a potent capacity of differentiating into constitutive cells of vessel walls. Additionally, with the paracrine secretion of various factors, PMSCs inextricably link and interact with other component cells in the placenta, collectively improving the placental vasculature, uterine spiral artery remolding, and uteroplacental interface immunoregulation. Recent studies have further indicated that preeclamptic PMSCs, closely implicated in the abnormal crosstalk between other ambient cells, disturb the homeostasis and development in the placenta. Nevertheless, PMSCs transplantation or PMSCs exosome therapies tend to improve the placental vascular network and trophoblastic functions in the PE model, suggesting PMSCs may be a novel and putative therapeutic strategy for PE. Herein, we provide an overview of the multifaceted contributions of PMSCs in early placental development. Thereinto, the intensive interactions between PMSCs and other component cells in the placenta were particularly highlighted and further extended to the implications in the pathogenesis and therapeutic strategies of PE.

Characteristics and regulation of mesenchymal stem cell plasticity by the microenvironment — specific factors involved in the regulation of MSC plasticity

Mesenchymal stem cells (MSCs), multipotent stromal cells, have attracted extensive attention in the field of regenerative medicine and cell therapy due to the capacity of self-renewal, multilineage differentiation, and immune regulation. MSCs have different cellular effects in different diseases, and even have markedly different curative effects with different tissue sources, indicating the plasticity of MSCs. The phenotypes, secreted factors, and proliferative, migratory, differentiating, and immunomodulatory effects of MSCs depend on certain mediators present in their microenvironment. Understanding microenvironmental factors and their internal mechanisms in MSC responses may help in subsequent prediction and improvement of clinical benefits. This review highlighted the recent advances in MSC plasticity in the physiological and pathological microenvironment and multiple microenvironmental factors regulating MSC plasticity. It also highlighted some progress in the underlying molecular mechanisms of MSC remodeling in the microenvironment. It might provide references for the improvement in vitro culture of MSCs, clinical application, and in vivo induction.

Stem Cell-Based Therapy for Diabetic Foot Ulcers

Diabetic foot ulcer has become a worldwide clinical medical challenge as traditional treatments are not effective enough to reduce the amputation rate. Therefore, it is of great social significance to deeply study the pathogenesis and biological characteristics of the diabetic foot, explore new treatment strategies and promote their application. Stem cell-based therapy holds tremendous promise in the field of regenerative medicine, and its mechanisms include promoting angiogenesis, ameliorating neuroischemia and inflammation, and promoting collagen deposition. Studying the specific molecular mechanisms of stem cell therapy for diabetic foot has an important role and practical clinical significance in maximizing the repair properties of stem cells. In addition, effective application modalities are also crucial in order to improve the survival and viability of stem cells at the wound site. In this paper, we reviewed the specific molecular mechanisms of stem cell therapy for diabetic foot and the extended applications of stem cells in recent years, with the aim of contributing to the development of stem cell-based therapy in the repair of diabetic foot ulcers.

Uncovering serum placental-related non-coding RNAs as possible biomarkers of preeclampsia risk, onset and severity revealed MALAT-1, miR-363 and miR-17

New predictors that could boost early detection of preeclampsia (PE) and prognosticate its severity are urgently needed. We examined serum miR-17, miR-363, MALAT-1 and HOTAIR as potential biomarkers of PE risk, onset and severity. This prospective study included 160 pregnant females; 82 PE cases and 78 healthy pregnancies. Serum samples were collected between 20 to 40 weeks of gestation. Early-onset PE was defined as developing clinical manifestations at ≤ 34 gestational weeks. Severe PE was defined as systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 110 mmHg and proteinuria (≥ 2 g/24 h or ≥ 2+ dipstick). Selection of PE-related non-coding RNAs and functional target gene analysis were conducted using bioinformatics analysis. Expression profiles were assessed by RT-qPCR. Serum miR-363 and MALAT-1 were downregulated, meanwhile miR-17 was upregulated, and HOTAIR was not significantly altered in PE compared with healthy pregnancies. miR-17 was elevated while miR-363 and MALAT-1 were reduced in severe versus mild PE. miR-363 was lower in early-onset versus late-onset PE. MALAT-1, miR-17 and miR-363 showed diagnostic potential and discriminated severe PE, whereas miR-363 distinguished early-onset PE in the receiver-operating-characteristic analysis. miR-363 and MALAT-1 were significantly associated with early and severe PE, respectively in multivariate logistic analysis. In PE, miR-17 and MALAT-1 were significantly correlated with gestational age (r = - 0.328 and r = 0.322, respectively) and albuminuria (r = 0.312, and r = - 0.35, respectively). We constructed the MALAT-1, miR-363, and miR-17-related protein-protein interaction networks linked to PE. Serum miR-17, miR-363 and MALAT-1 could have utility as new biomarkers of PE diagnosis. miR-363 may be associated with early-onset PE and MALAT-1 downregulation correlates with PE severity.

The role of mesenchymal stem cells in the occurrence, development, and therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of liver malignant tumor, with high recurrence and mortality rates. Mesenchymal stem cells (MSCs) are multipotent cells that can be recruited into the tumor microenvironment (TME). What is known, TME plays a vital part in tumor progression. In recent years, accumulating studies have found that MSCs have a dual role of promotion and inhibition in the occurrence and development of HCC. In this review, we analyzed the role of MSCs in TME and summarized the relationship between MSCs and liver cancer stem cells, the molecular signaling pathway mechanisms of MSCs promoting and inhibiting HCC, and the latest research progress of MSCs in the treatment of HCC.

Competing endogenous RNA network associated with oxygen-induced retinopathy: Expression of the network and identification of the MALAT1/miR-124-3p/EGR1 regulatory axis

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124-3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124-3p was selected for additional study. miR-124-3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124-3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124-3p. In vivo, intravitreal injection of miR-124-3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124-3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124-3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

Circulating MicroRNAs in the Second Trimester From Pregnant Women Who Subsequently Developed Preeclampsia: Potential Candidates as Predictive Biomarkers and Pathway Analysis for Target Genes of miR-204-5p

MicroRNAs (miRNAs) play an important role in the pathophysiology of preeclampsia (PE). However, the expression of circulating miRNAs was not analyzed in the second trimester of pregnancy, a period of major relevance to identify predictive biomarkers for PE. Therefore, we examined the expression profiles of 84 circulating miRNAs using a PCR array in plasma collected between 20 and 25 weeks of gestation from pregnant women, who subsequently developed PE and those who remained healthy during pregnancy, randomly selected from a prospective cohort. Overall, 23 miRNAs had a fold change > 2.0 and were considered to be upregulated in plasma from pregnant women who subsequently developed PE, even before the onset of clinical symptoms of PE. However, only miR-204-5p was statistically significant (P = 0.0082). Experimentally validated interactions for the target genes of miR-204-5p extracted from miRTarBase were used in the gene set functional enrichment analysis to identify Reactome pathways. The network connecting the 37 target genes for miR-204-5p revealed pathways of known pathophysiological relevance during the early development of PE and included key genes related to PE, such as BDNF, MMP-9, MALAT1, TGFBR2, and SIRT1. We further depicted downstream targets of SIRT1 that are related to the vascular endothelial function or implicated in the pathophysiology of PE, namely, FOXO1, NFκB, HIF-1α, NOS3, and PPAR-γ. Our novel findings provide for circulating miRNAs upregulated in the second trimester on plasma from pregnant women who subsequently developed PE that is potentially related to the early development of PE, which may guide further studies focused on the validation of potential predictive biomarkers in PE.

LncRNA MALAT1 Facilitates Ovarian Cancer Progression through Promoting Chemoresistance and Invasiveness in the Tumor Microenvironment

Upregulation of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1, also known as nuclear-enriched abundant transcript 2 (NEAT2) or LINC00047) was found in various solid tumors, including epithelial ovarian cancer (EOC). MALAT1 is a long noncoding (lnc)RNA that regulates many functional signaling pathways, including tumorigenesis. Herein, we observed the consistent upregulation of MALAT1 in MYST4-overexpressing cell lines, while MALAT1 was frequently found to be upregulated in various types of clinical carcinoma tissues, especially EOC. To further investigate the lncRNA MALAT1 in EOC progression, the transduced overexpression of MALAT1 in EOC cell lines and cancer-associated fibroblasts (CAFs) was employed. We found that MALAT1 overexpression in EOC cell lines significantly increased drug resistance, cell migration, and invasion. Furthermore, the concomitant overexpression of MALAT1 in EOC cells and CAFs dramatically increased EOC cell invasion. Accordingly, a mechanistic investigation of MALAT1 overexpression in EOC cells showed that expressions of the cytokines interleukin (IL)-1β and p-P38/p-NFκB/Cox2/prostaglandin E2 (PGE2) signaling were significantly increased, which stimulated inflammatory responses, whereas cell apoptosis was inhibited due to increased Bcl-2 levels and reduced Caspase3 levels. After MALAT1 was overexpressed in EOC cells, and the cyclin D1, p-PI3K, and p-Akt expressions increased, suggesting the promotion of tumor cell proliferation, while increased zinc finger E-box-binding homeobox-2 (ZEB2), yes-associated protein (YAP), and vimentin expression with E-cadherin downregulation indicated the enhancement of the epithelial-to-mesenchymal transition (EMT) in terms of metastasis, thereby triggering EOC progression. Together, our findings demonstrate how MALAT1 overexpression facilitates an oncogenic function through inhibiting tumor cell apoptosis, combined with increasing tumor cell inflammation, proliferation, and invasion in the EOC tumor microenvironment. MALAT1 is thus a potential diagnostic marker and therapeutic for this malignancy.

Tryptophan 2,3-dioxygenase 2 controls M2 macrophages polarization to promote esophageal squamous cell carcinoma progression via AKT/GSK3β/IL-8 signaling pathway

Tryptophan 2,3-dioxygnease 2 (TDO2) is specific for metabolizing tryptophan to kynurenine (KYN), which plays a critical role in mediating immune escape of cancer. Although accumulating evidence demonstrates that TDO2 overexpression is implicated in the development and progression of multiple cancers, its tumor-promoting role in esophageal squamous cell carcinoma (ESCC) remains unclear. Here, we observed that TDO2 was overexpressed in ESCC tissues and correlated significantly with lymph node metastasis, advanced clinical stage, and unfavorable prognosis. Functional experiments showed that TDO2 promoted tumor cell proliferation, migration, and colony formation, which could be prevented by inhibition of TDO2 and aryl hydrocarbon receptor (AHR). Further experimentation demonstrated that TDO2 could promote the tumor growth of KYSE150 tumor-bearing model, tumor burden of C57BL/6 mice with ESCC induced by 4-NQO, enhance the expression of phosphorylated AKT, with subsequent phosphorylation of GSK3β, and polarization of M2 macrophages by upregulating interleukin-8 (IL-8) to accelerate tumor progression in the tumor microenvironment (TME). Collectively, our results discovered that TDO2 could upregulate IL-8 through AKT/GSK3β to direct the polarization of M2 macrophages in ESCC, and suggested that TDO2 could represent as an attractive therapeutic target and prognostic marker to ESCC.

Modulating immune microenvironment during bone repair using biomaterials: Focusing on the role of macrophages

Bone is a self-regenerative tissue that can repair small defects and fractures. In large defects, bone tissue is unable to provide nutrients and oxygen for repair, and autologous grafting is used as the gold standard. As an alternative method, the bone tissue regeneration approach uses osteoconductive biomaterials to overcome bone graft disadvantages. However, biomaterials are considered as foreign components that can stimulate host immune responses. Although traditional principles have been aimed to minimize immune reactions, the design of biomaterials has steadily shifted toward creating an immunomodulatory microenvironment to harness immune cells and responses to repair damaged tissue. Among immune cells, macrophages secrete various immunomodulatory mediators and crosstalk with bone-forming cells and play key roles in bone tissue engineering. Macrophage polarization toward M1 and M2 subtypes mediate pro-inflammatory and anti-inflammatory responses, respectively, which are crucial for bone repairing at different stages. This review provides an overview of the crosstalk between various immune cells and biomaterials, macrophage polarization, and the effect of physicochemical properties of biomaterials on the immune responses, especially macrophages, in bone tissue engineering.

The Impact of lncRNAs and miRNAs on Apoptosis in Lung Cancer

Apoptosis is a coordinated cellular process that occurs in several physiological situations. Dysregulation of apoptosis has been documented in numerous pathological situations, particularly cancer. Non-coding RNAs regulate apoptosis via different mechanisms. Lung cancer is among neoplastic conditions in which the role of non-coding RNAs in the regulation of apoptosis has been investigated. Non-coding RNAs that regulate apoptosis in lung cancer have functional interactions with PI3K/Akt, PTEN, GSK-3β, NF-κB, Bcl-2, Bax, p53, mTOR and other important cancer-related pathways. Globally, over-expression of apoptosis-blocking non-coding RNAs has been associated with poor prognosis of patients, while apoptosis-promoting ones have the opposite effect. In the current paper, we describe the impact of lncRNAs and miRNAs on cell apoptosis in lung cancer.

Roles of exosomes-derived lncRNAs in preeclampsia

Preeclampsia is a pregnancy-specific hypertensive syndrome, which seriously threatens the safety of mother and infant. However, there is still no accurate biomarkers for the diagnosis of preeclampsia, and its etiology and pathogenesis have not been fully elucidated. Exosomes are extracellular vesicles widely existing in body fluids, which carry a variety of bioactive molecules such as proteins, lipids and nucleic acids with various biological functions. The lncRNAs carried by exosomes are characterized by specificity, plurality, anti-degradation and stable detection. Multiple differentially expressed lncRNAs were found in exosomes secreted by placental tissues of patients with preeclampsia, suggesting that they may be involved in the occurrence and development of preeclampsia. In this paper, we summarized the structures and functions of exosomes-derived lncRNAs and their relationships with preeclampsia in order to provide new ideas for the pathogenesis, early prediction, diagnosis and treatment of preeclampsia.

Long noncoding RNA network: Novel insight into hepatocellular carcinoma metastasis (Review)

Hepatocellular carcinoma (HCC) is one of the most common, aggressive malignancies with poor prognosis and high mortality. Although great progress has been made in recent decades, overall survival of HCC patients remains unsatisfactory due to high recurrence and metastasis. Accordingly, understanding and clarifying the underlying molecular mechanisms of metastasis has become increasingly important. Recently, accumulated reports have supported that long noncoding RNAs (lncRNAs) are dysregulated in HCC and are involved in various pivotal biological processes, including metastasis. The aim of this review was to investigate the dysregulation of lncRNAs in HCC and their function as oncogenes or tumour suppressors. Furthermore, reciprocal regulatory networks between lncRNAs and various molecules that were identified in HCC metastasis, including regulating epithelial-mesenchymal transition (EMT), controlling metastasis-associated genes, and regulating tumour angiogenesis were examined. Numerous reports and information on lncRNAs may help identify lncRNAs that are potential novel diagnostic markers, prognostic markers and therapeutic targets.

Recent Advances of MicroRNAs, Long Non-coding RNAs, and Circular RNAs in Preeclampsia

Preeclampsia is a clinical syndrome characterized by multiple-organ dysfunction, such as maternal hypertension and proteinuria, after 20 weeks of gestation. It is a common cause of fetal growth restriction, fetal malformation, and maternal death. At present, termination of pregnancy is the only way to prevent the development of the disease. Non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, are involved in important pathological and physiological functions in life cycle activities including ontogeny, reproduction, apoptosis, and cell reprogramming, and are closely associated with human diseases. Accumulating evidence suggests that non-coding RNAs are involved in the pathogenesis of preeclampsia through regulation of various physiological functions. In this review, we discuss the current evidence of the pathogenesis of preeclampsia, introduce the types and biological functions of non-coding RNA, and summarize the roles of non-coding RNA in the pathophysiological development of preeclampsia from the perspectives of oxidative stress, hypoxia, angiogenesis, decidualization, trophoblast invasion and proliferation, immune regulation, and inflammation. Finally, we briefly discuss the potential clinical application and future prospects of non-coding RNA as a biomarker for the diagnosis of preeclampsia.

miRNAs and lncRNAs as Novel Therapeutic Targets to Improve Cancer Immunotherapy

Simple Summary

Cancer onset and progression are promoted by high deregulation of the immune system. Recently, major advances in molecular and clinical cancer immunology have been achieved, offering new agents for the treatment of common tumors, often with astonishing benefits in terms of prolonged survival and even cure. Unfortunately, most tumors are still resistant to current immune therapy approaches, and basic knowledge of the resistance mechanisms is eagerly awaited. We focused our attention on noncoding RNAs, a class of RNA that regulates many biological processes by targeting selectively crucial molecular pathways and that, recently, had their role in cancer cell immune escape and modulation of the tumor microenvironment identified, suggesting their function as promising immunotherapeutic targets. In this scenario, we point out that noncoding RNAs are progressively emerging as immunoregulators, and we depict the current information on the complex network involving the immune system and noncoding RNAs and the promising therapeutic options under investigation. Novel opportunities are emerging from noncoding-RNAs for the treatment of immune-refractory tumors.

Abstract

Immunotherapy is presently one of the most promising areas of investigation and development for the treatment of cancer. While immune checkpoint-blocking monoclonal antibodies and chimeric antigen receptor (CAR) T-cell-based therapy have recently provided in some cases valuable therapeutic options, the goal of cure has not yet been achieved for most malignancies and more efforts are urgently needed. Noncoding RNAs (ncRNA), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), regulate several biological processes via selective targeting of crucial molecular signaling pathways. Recently, the key roles of miRNA and lncRNAs as regulators of the immune-response in cancer have progressively emerged, since they may act (i) by shaping the intrinsic tumor cell and microenvironment (TME) properties; (ii) by regulating angiogenesis, immune-escape, epithelial-to-mesenchymal transition, invasion, and drug resistance; and (iii) by acting as potential biomarkers for prognostic assessment and prediction of response to immunotherapy. In this review, we provide an overview on the role of ncRNAs in modulating the immune response and the TME. We discuss the potential use of ncRNAs as potential biomarkers or as targets for development or clinical translation of new therapeutics. Finally, we discuss the potential combinatory approaches based on ncRNA targeting agents and tumor immune-checkpoint inhibitor antibodies or CAR-T for the experimental treatment of human cancer.

Long non-coding RNA MALAT1 plays a protective role in bronchopulmonary dysplasia via the inhibition of apoptosis and interaction with the Keap1/Nrf2 signal pathway

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common respiratory disease in premature infants and is characterized by alveolar and pulmonary vascular dysplasia. Long-term oxygen exposure can cause BPD in preterm infants. Numerous studies have shown that long non-coding ribonucleic acid (lncRNA) is involved in the process of biological metabolism; however, its role in the development of BPD is unclear. Apoptosis-induced factor (AIF) is a key component involved in apoptosis. The Kelch-like ECH-associated protein 1/nuclear factor erythroid-2-related factor 2 (Keap1/Nrf2) signaling pathway is a body-derived antioxidant signaling pathway.

METHODS

In this study, the relative expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), AIF, Keap1, and Nrf2 was detected by real-time polymerase chain reaction (PCR). Also, the apoptosis of A549 cells was detected by flow cytometry.

RESULTS

The results showed that, compared to the control group, the expression of MALAT1 increased significantly, and AIF decreased substantially in BPD premature infants. In the A549 hyperoxic lung injury model, compared with the air group, the expression of MALAT1 in the hyperoxia group decreased markedly, while the expression of Keap1 and Nrf2 increased considerably. Furthermore, compared with the control plasmid transfection air group (NC group), the expression of Keap1 and Nrf2 increased significantly in the small interfering RNA (siRNA) group.

CONCLUSIONS

These results indicate that MALAT1 can play a protective role in BPD via the reduction of apoptosis and anti-oxidation, offering clinicians a new way to prevent and treat BPD.

MALAT1 sponges miR-26a and miR-26b to regulate endothelial cell angiogenesis via PFKFB3-driven glycolysis in early-onset preeclampsia

6-phosphofructo-2-kinase (PFKFB3) is a crucial regulator of glycolysis that has been implicated in angiogenesis and the development of diverse diseases. However, the functional role and regulatory mechanism of PFKFB3 in early-onset preeclampsia (EOPE) remain to be elucidated. According to previous studies, noncoding RNAs play crucial roles in EOPE pathogenesis. The goal of this study was to investigate the functional roles and co-regulatory mechanisms of the metastasis-associated lung adenocarcinoma transcript-1 (MALAT1)/microRNA (miR)-26/PFKFB3 axis in EOPE. In our study, decreased MALAT1 and PFKFB3 expression in EOPE tissues correlates with endothelial cell (EC) dysfunction. The results of in vitro assays revealed that PFKFB3 regulates the proliferation, migration, and tube formation of ECs by modulating glycolysis. Furthermore, MALAT1 regulates PFKFB3 expression by sponging miR-26a/26b. Finally, MALAT1 knockout reduces EC angiogenesis by inhibiting PFKFB3-mediated glycolysis flux, which is ameliorated by PFKFB3 overexpression. In conclusion, decreased MALAT1 expression in EOPE tissues reduces the glycolysis of ECs in a PFKFB3-dependent manner by sponging miR-26a/26b and inhibits EC proliferation, migration, and tube formation, which may contribute to abnormal angiogenesis in EOPE. Thus, strategies targeting PFKFB3-driven glycolysis may be a promising approach for the treatment of EOPE.

Exosomal Long Non-Coding RNA: Interaction Between Cancer Cells and Non-Cancer Cells

Exosomes are small membranous vesicles released by many kinds of cells, and are indispensable in cell-to-cell communication by delivering functional biological components both locally and systemically. Long non-coding RNAs (lncRNAs) are long transcripts over 200 nucleotides that exhibit no or limited protein-coding potentials. LncRNAs are dramatic gene expression regulators, and can be selectively sorted into exosomes. Exosomal lncRNAs derived from cancer cells and stromal cells can mediate the generation of pre-metastatic niches (PMNs) and thus promote the progression of cancer. In this review, we summarized the fundamental biology and characteristics of exosomal lncRNAs. Besides, we provided an overview of current research on functions of exosomal lncRNAs between cancer cells and non-cancer cells. A deep understanding of exosomal lncRNAs' role in cancer will be facilitated to find important implications for cancer development and treatment.

Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.

Regulatory Networks of LncRNA MALAT-1 in Cancer

Long noncoding (lnc)RNAs are a group of RNAs with a length greater than 200 nt that do not encode a protein but play an essential role in regulating the expression of target genes in normal biological contexts as well as pathologic processes including tumorigenesis. The lncRNA metastasis-associated lung adenocarcinoma transcript (MALAT)-1 has been widely studied in cancer. In this review, we describe the known functions of MALAT-1; its mechanisms of action; and associated signaling pathways and their clinical significance in different cancers. In most malignancies, including lung, colorectal, thyroid, and other cancers, MALAT-1 functions as an oncogene and is upregulated in tumors and tumor cell lines. MALAT-1 has a distinct mechanism of action in each cancer type and is thus at the center of large gene regulatory networks. Dysregulation of MALAT-1 affects cellular processes such as alternative splicing, epithelial–mesenchymal transition, apoptosis, and autophagy, which ultimately results in the abnormal cell proliferation, invasion, and migration that characterize cancers. In other malignancies, such as glioma and endometrial carcinoma, MALAT-1 functions as a tumor suppressor and thus forms additional regulatory networks. The current evidence indicates that MALAT-1 and its associated signaling pathways can serve as diagnostic or prognostic biomarker or therapeutic target in the treatment of many cancers.

The tRNA-like small noncoding RNA mascRNA promotes global protein translation

mascRNA is a small cytoplasmic RNA derived from the lncRNA MALAT1. After being processed by the tRNA processing enzymes RNase P and RNase Z, mascRNA undergoes CCA addition like tRNAs and folds into a tRNA-like cloverleaf structure. While MALAT1 functions in multiple cellular processes, the role of mascRNA was largely unknown. Here, we show that mascRNA binds directly to the multi-tRNA synthetase complex (MSC) component glutaminyl-tRNA synthetase (QARS). mascRNA promotes global protein translation and cell proliferation by positively regulating QARS protein levels. Our results uncover a role of mascRNA that is independent of MALAT1, but could be part of the molecular mechanism of MALAT1's function in cancer, and provide a paradigm for understanding tRNA-like structures in mammalian cells.

Increase in MEG3, MALAT1, NEAT1 significantly predicts the clinical parameters in patients with rheumatoid arthritis

Aim: This study investigated deregulation of lncRNAs MEG3, MALAT1, NEAT1 and their associations with clinical parameters in rheumatoid arthritis (RA). Materials & methods: LncRNAs MALAT1, MEG3, NEAT1 were quantified from peripheral blood mono-nuclear cells (PBMCs) and plasma of 82 RA patients with 15 matched controls and from knee fluid of 24 RA patients with ten osteoarthritis controls. Multivariate analyses were performed among lncRNAs and clinical parameters of RA. Results: MALAT1, MEG3, NEAT1 were increased in PBMCs, plasma, synovial fluid (p < 0.05) of RA patients. Significant correlations were observed for MEG3 with TJC (r = 0.29), NEAT1 with TJC (r = 0.49), swollen joint count (r = 0.20), DAS28-CRP (r = 0.29). Multivariate analysis revealed that 48.5% of TJC and 31.5% of swollen joint count could be predicted by lncRNAs. Conclusion: The findings suggested that the lncRNAs might be explored as probable markers in monitoring disease activity.

Hyperbaric oxygen-induced long non-coding RNA MALAT1 exosomes suppress MicroRNA-92a expression in a rat model of acute myocardial infarction

Hyperbaric oxygen (HBO) improves angiogenesis. The effect of HBO on metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1), a pro‐angiogenic long non‐coding RNA, in cardiac myocyte‐derived exosomes and acute myocardial infarction (AMI) is unknown. We aimed to investigate whether MALAT1 is altered in cardiac myocyte‐derived exosomes in response to HBO as well as the molecular regulatory mechanisms of MALAT1 in cardiac myocytes treated with HBO. Cardiac myocytes were cultured, and HBO was applied at 2.5 atmosphere absolute in a hyperbaric chamber. Exosomes were extracted from the culture media. A rat model of AMI generated by the ligation of the left anterior descending artery was used. HBO significantly increased MALAT1 expression in cardiac myocytes and HBO‐induced MALAT1 and exosomes attenuated miR‐92a expression after myocardial infarction. Expression of krüppel‐like factor 2 (KLF2) and CD31 was significantly decreased after infarction and HBO‐induced exosomes significantly reversed the expression. Silencing of MALAT1 using MALAT1‐locked nucleic acid GapmeR significantly attenuated KLF2 and CD31 protein expression after infarction induced by HBO‐induced exosomes. HBO‐induced exosomes also decreased infarct size significantly. HBO‐induced exosomes from cardiac myocytes up‐regulate MALAT1 to suppress miR‐92a expression and counteract the inhibitory effect of miR‐92a on KLF2 and CD31 expression in left ventricular myocardium after myocardial infarction to enhance neovascularization.

Reduced serum and local LncRNA MALAT1 expressions are linked with disease severity in patients with non-traumatic osteonecrosis of the femoral head

OBJECTIVE

This study was performed to illustrate the potential relationship between reduced serum and local LncRNA MALAT1 expressions with disease severity in patients with non-traumatic osteonecrosis of the femoral head (ONFH).

METHODS

A total of 104 patients with non-traumatic ONFH and 100 healthy controls were consecutively recruited from our hospital. Serum and local LncRNA MALAT1 expressions were detected using real-time polymerase chain reaction (RT-PCR). Radiographic progression was defined by Ficat classification. Clinical severity was evaluated by Visual Analog Scale (VAS) and Harris Hip Score (HHS). Receiver operating characteristic (ROC) curve was carried out to determine the diagnostic value of MALAT1 in the radiographic progression.

RESULTS

Serum LncRNA MALAT1 expressions were significantly lower in non-traumatic ONFH patients than in healthy controls. In addition, local MALAT1 expressions in non-traumatic ONFH tissue were significantly lower in the affected area than in the non-affected area. Ficat grade 4 has significantly lower serum and local LncRNA MALAT1 expressions in comparison with grade 3, and Ficat grade 3 showed markedly decreased serum and local LncRNA MALAT1 expressions compared with grade 2. Serum and local LncRNA MALAT1 expressions were significantly and negatively associated with VAS and positively related to the HHS. Further ROC curve analysis indicated that serum MALAT1 may act as a decent indicator in the diagnosis of non-traumatic ONFH.

CONCLUSIONS

Decreased serum and local MALAT1 expressions may reflect disease severity in non-traumatic ONFH patients.

Noncoding RNAs: the shot callers in tumor immune escape

Immunotherapy, designed to exploit the functions of the host immune system against tumors, has shown considerable potential against several malignancies. However, the utility of immunotherapy is heavily limited due to the low response rate and various side effects in the clinical setting. Immune escape of tumor cells may be a critical reason for such low response rates. Noncoding RNAs (ncRNAs) have been identified as key regulatory factors in tumors and the immune system. Consequently, ncRNAs show promise as targets to improve the efficacy of immunotherapy in tumors. However, the relationship between ncRNAs and tumor immune escape (TIE) has not yet been comprehensively summarized. In this review, we provide a detailed account of the current knowledge on ncRNAs associated with TIE and their potential roles in tumor growth and survival mechanisms. This review bridges the gap between ncRNAs and TIE and broadens our understanding of their relationship, providing new insights and strategies to improve immunotherapy response rates by specifically targeting the ncRNAs involved in TIE.

Long noncoding RNAs in endometriosis: Biological functions, expressions, and mechanisms

Endometriosis refers to a benign chronic gynecological disorder, and is defined as the ectopic growth of endometrium in pelvic cavity. Endometriosis affects about 10% of reproductive-aged women. Unfortunately, the pathogenesis of endometriosis remains obscure, and the disease witnesses a lack of effective therapy approaches. Therefore, more research needs to be performed to throw light on endometriosis, its pathogenesis, and therapy. Long noncoding RNAs (lncRNAs), which are defined as functional cellular RNA longer than 200 nucleotides, have been implicated in many chronic disorders. It has been suggested that lncRNAs are closely related to the endometriosis process. Nevertheless, the molecular mechanisms by which lncRNAs associate with endometriosis should be elucidated more detailed. In our brief review, we first exhibit the aberrant lncRNAs expression in endometriosis. Then, we talk about the molecular mechanisms underlying lncRNAs in endometriosis. Finally, we also present the potential of lncRNAs as biomarkers for endometriosis.

Emerging Therapeutic Potential of Mesenchymal Stem/Stromal Cells in Preeclampsia

PURPOSE OF REVIEW

Preeclampsia is a dangerous pregnancy condition affecting both the mother and offspring. It is a multifactorial disease with poorly understood pathogenesis, lacking effective treatments. Maternal immune response, inflammation and oxidative stress leading to endothelial dysfunction are the most prominent pathogenic processes implicated in preeclampsia development. Here, we give a detailed overview of the therapeutic applications and mechanisms of mesenchymal stem/stromal cells (MSCs) as a potential new treatment for preeclampsia.

RECENT FINDINGS

MSCs have gained growing attention due to low immunogenicity, easy cultivation and expansion in vitro. Accumulating evidence now suggests that MSCs act primarily through their secretomes facilitating paracrine signalling that leads to potent immunomodulatory, pro-angiogenic and regenerative therapeutic effects. MSCs have been studied in different animal models of preeclampsia demonstrating promising result, which support further investigations into the therapeutic effects and mechanisms of MSC-based therapies in preeclampsia, steering these therapies into clinical trials.

Estrogen Promotes cAMP Production in Mesenchymal Stem Cells by Regulating ADCY2

Background and Objectives

The maternal-fetal interface is an important source of mesenchymal stem cells (MSCs), and it is influenced by high levels of estradiol (E2) during pregnancy. It is highly important to study the role of E2 in MSCs for both clinical application and understanding of the mechanisms underlying pregnancy related diseases.

Methods and Results

In this study, differently expressed genes (DEGs) were found in the MSCs after exposure to E2. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs was performed and the integrated regulatory network of DEGs-miRNA was constructed. A total of 390 DEGs were found in the MSCs exposed to E2, including 164 upregulated DEGs (e.g. ADCY2, VEGFA and PPY) and 226 downregulated DEGs (e.g. KNG1, AGT and NPY). Additionally, 10 miRNAs (such as miR-148A/B, miR-152, miR-182) identified the integrated regulatory network of DEGs-miRNAs. Among them, the expression of ADCY2 was significantly upregulated, and this was associated with multiple changed genes. We confirmed that the expression of ADCY2 is significantly promoted by E2 and subsequently promoted the production of cAMP in MSCs. We also found that E2 promoted ADCY2 expression by inhibiting miR-152 and miR-148a.

Conclusions

E2 promotes the expression of cAMP through miR-148a/152-ADCY2 in MSCs. It is suggested that E2 plays a key role in the growth and function of MSCs.

Downregulation of Long Noncoding RNA MIAT in the Retina of Diabetic Rats with Tail-vein Injection of Human Umbilical-cord Mesenchymal Stem Cells

Diabetic retinopathy (DR) is the common and important cause for visual impairment and blindness in working-aged people. Microangiopathy and inflammatory reactions are the key components of DR. Recently, long non-coding RNA myocardial infarction-associated transcript (MIAT) has emerged as a vital player in regulation for inflammatory processes and microvascular dysfunction. Additionally, cell-based therapy provides a potential option for the treatment of DR. The anti-inflammatory effects and repair therapy of mesenchymal stem cells (MSCs) have been paid more attention. This study investigated the effects of human umbilical-cord mesenchymal stem cells (HUMSCs) injection on diabetic rat model. The results show that the level of MIAT is significantly decreased in the diabetic retina after the injection of HUMSCs. Moreover, HUMSCs can significantly decrease the expression of IL-1β and IL-6 mRNA; alleviate microvascular permeability, and upregulate Occludin expression. Studies have shown that MIAT knockdown could alleviate diabetes-induced inflammation responses and vascular leakage. Furthermore, our findings also showed that the expression of MIAT was positively correlated with the expression of IL-1β and IL-6. These results suggest that MIAT might play important regulatory roles in alleviating inflammatory reactions and microangiopathy inducing by DR after transplantation of HUMSCs.

Resveratrol improves the therapeutic efficacy of bone marrow-derived mesenchymal stem cells in rats with severe acute pancreatitis

OBJECTIVE

Bone marrow-derived mesenchymal stem cells (BMSCs) are effective in the treatment of severe acute pancreatitis (SAP), but their therapeutic effects could still be improved. In order to optimize the clinical application of BMSCs, we adopted the strategy of resveratrol (Res) pretreatment of BMSCs (Res-BMSCs) and applied it to a rat model of sodium taurocholate (NaT)-induced acute pancreatitis.

METHODS

SAP was induced by injection of 3% NaT into the pancreatic duct and successful induction of SAP occurred after 12 h. Rats were treated with BMSCs, Res or BMSCs primed with Res at 40 mmol/L, Vandetanib (ZD6474) daily oral dosages of 50 mg/kg vandetanib.

RESULTS

Res stimulated BMSCs to secrete vascular endothelial growth factor A (VEGFA), activated the downstream phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and inhibited pancreatic cell apoptosis. In addition, conditioned medium (CM) from Res-BMSCs enhanced the proliferation of human umbilical vein endothelial cells (HUVECs) in vitro, increased resistance to apoptosis and promoted the expression of angiogenesis-related proteins CD31, VEGF and VEGFR2 in pancreatic tissue, but Vandetanib partly abolished these effects by blocking the VEGFA- mediated pathway.

CONCLUSION

Resveratrol-preprocessed BMSCs can activate the PI3K/AKT signaling pathway in pancreatic cells and HUVECs through paracrine release of VEGFA; thus, achieving the therapeutic effect of resisting apoptosis of pancreatic cells and promoting regeneration of damaged blood vessels. Res pretreatment may be a new strategy to improve the therapeutic effect of BMSCs on SAP.