Requirement of miR-144 in CsA Induced Proliferation and Invasion of Human Trophoblast Cells by Targeting Titin

Loss of connectin novex-3 leads to heart dysfunction associated with impaired cardiomyocyte proliferation and abnormal nuclear mechanics

Connectin (also known as titin) is a giant striated muscle protein that functions as a molecular spring by providing elasticity to the sarcomere. Novex-3 is a short splice variant of connectin whose physiological function remains unknown. We have recently demonstrated using in vitro analyses that in addition to sarcomere expression, novex-3 was also expressed in cardiomyocyte nuclei exclusively during fetal life, where it provides elasticity/compliance to cardiomyocyte nuclei and promotes cardiomyocyte proliferation in the fetus, suggesting a non-sarcomeric function. Here, we analyzed novex-3 knockout mice to assess the involvement of this function in cardiac pathophysiology in vivo. Deficiency of novex-3 compromised fetal cardiomyocyte proliferation and induced the enlargement of individual cardiomyocytes in neonates. In adults, novex-3 deficiency resulted in chamber dilation and systolic dysfunction, associated with Ca2+ dysregulation, resulting in a reduced life span. Mechanistic analyses revealed a possible association between impaired proliferation and abnormal nuclear mechanics, including stiffer nuclei positioned peripherally with stabilized circumnuclear microtubules in knockout cardiomyocytes. Although the underlying causal relationships were not fully elucidated, these data show that novex-3 has a vital non-sarcomeric function in cardiac pathophysiology and serves as an early contributor to cardiomyocyte proliferation.

Cyclosporin A alleviates trophoblast apoptosis and senescence by promoting autophagy in preeclampsia

INTRODUCTION

Abnormal extravillous trophoblast (EVT) function is closely related to preeclampsia (PE) and may be caused by inadequate autophagy, apoptosis, and senescence. Cyclosporin A (CsA) is an effective immunosuppressant that has been reported to stimulate autophagy and exert benign biological effects on EVTs. Therefore, we hypothesized that CsA may display therapeutic efficacy against PE by activating autophagy.

METHODS

We established the nitro-l-arginine methyl ester (l-NAME)-induced preeclamptic mice model and a hypoxia-reoxygenation (H/R) model in vitro. The effects of CsA on autophagy were evaluated by western blotting (WB). The effects of CsA on apoptosis were analyzed by Hematoxylin-eosin (H&E) staining, cell apoptosis assay and WB. Senescence-associated β-galactosidase (SA-β-gal) staining, RT-qPCR and WB were used to examine the senescence level. RT-qPCR were used to detect the senescence-associated secretory phenotype (SASP) level. DCFH-DA fluorescent probe, dihydroethidium (DHE) staining and mitochondrial membrane potential (ΔΨm) were used to detect senescence-associated mitochondrial dysfunction (SAMD).

RESULTS

CsA alleviated PE-like symptoms and reduced placental necrosis and senescence in mice injected with l-NAME. CsA ameliorated placental SASP and SAMD level induced by l-NAME. CsA also upregulated the expression of autophagic proteins in mouse placentas disrupted using l-NAME. In vitro, we found that CsA reversed H/R-induced apoptosis and senescence, as well as decreasing SASP and SAMD levels and upregulating autophagic proteins levels. Notably, 3-methyladenine (3-MA), an early phase inhibitor of autophagosome formation, abolished the protective effects of CsA against H/R.

DISCUSSION

CsA may display some therapeutic effects against PE by activating autophagy in vivo and in vitro.

MicroRNA‑491‑5p inhibits trophoblast cell migration and invasion through targeting matrix metalloproteinase‑9 in preeclampsia

Insufficient invasion of trophoblasts is correlated with the development of preeclampsia (PE). MicroRNA (miR)-491-5p has been reported to be implicated in human cancer cell invasion; however, whether miR-491-5p is involved in the development of PE remains largely unclear. The aim of the present study was to investigate the role of miR-491-5p in trophoblastic invasion in vitro and to determine its underlying mechanism of action. The expression levels of miR-491-5p were validated using reverse transcription-quantitative PCR. The effects of miR-491-5p on trophoblast cell invasion were evaluated in vitro. Then, the association between miR-491-5p and its downstream target was investigated in both cell lines and clinical specimens. miR-491-5p expression levels were observed to be significantly increased in the placental tissues from patients with PE. The invasive capacity of HTR-8/SVneo trophoblast cells was suppressed following the upregulation of miR-491-5p and increased following the inhibition of miR-491-5p. Matrix metalloproteinase-9 (MMP-9), a well-known regulator of trophoblast cell invasion, was discovered to be a direct target of miR-491-5p in HTR-8/SVneo trophoblast cells. Moreover, miR-491-5p expression levels were found to be inversely correlated with MMP-9 expression levels in placental tissues from patients with PE. The overexpression of MMP-9 partly attenuated the inhibitory effects of miR-491-5p on HTR-8/SVneo trophoblast cells invasion. Collectively, these findings suggested that the aberrant expression of miR-491-5p may contribute to PE through suppressing trophoblast invasion, thus highlighting the novel roles of miR-491-5p in the molecular pathogenesis of PE. The present study also showed that the miR-491-5p/MMP-9 axis may be an effective biomarker or a viable drug target for therapeutic intervention in PE.

Dysregulation of liver developmental microRNA contribute to hepatic carcinogenesis

BACKGROUND/PURPOSE

To investigate the role of microRNA (miRNA) dysregulation in liver cancer by assessing the miRNA profiles of human hepatic stem cells (HpSCs), marker-carrying human hepatoblastoma (HB) cells, and hepatocellular carcinoma (HCC) cells vs. those of fetal hepatocytes.

METHODS

We subjected human HCC and HB tumor specimens to immunohistochemical (IHC) staining for markers of HpSCs. We analyzed the miRNA patterns of HpSCs, HCC cells, HB cells, and fetal hepatocytes using microarray analysis, with confirmation via quantitative real-time polymerase chain reaction. The roles of the miRNAs in liver cancer stem cells (CSCs) were also elucidated.

RESULTS

The epithelial cell adhesion molecule (EpCAM) was the most prevalent HpSCs marker in human HB and HCC tumor cells and hepatoma cells. EpCAM-positive HB and HCC cells exhibited greater self-renewal and tumorigenicity than their EpCAM-negative counterparts or EpCAM-positive fetal hepatocytes. In EpCAM-positive fetal hepatocytes, miR-126 expression level increased with gestational age. The EpCAM-positive HB cells exhibited downregulation of miR-126 in comparison to EpCAM-positive fetal hepatocytes. An miR-126 mimic reduced sphere and colony formation in, and induced apoptosis of, HB cells. In comparison to EpCAM-positive fetal hepatocytes, EpCAM-positive HCC cells exhibited downregulation of miR-126, miR-144, and miR-451. Transfection of miR-126, miR-144, and miR-451 induced apoptosis of, and reduced sphere and colony formation in, HCC cells.

CONCLUSION

Dysregulation of liver developmental miRNAs, which exert a tumor suppressant effect, in EpCAM-positive HpSCs may contribute to liver carcinogenesis by promoting the transformation of HpSCs to CSCs of HB and HCC.

MicroRNA-144 targets APP to regulate AML1/ETO+ leukemia cell migration via the p-ERK/c-Myc/MMP-2 pathway

Extramedullary infiltration (EMI) is common in patients with acute myeloid leukemia (AML) and is closely associated with the prognosis of disease. We previously reported that patients carrying the AML1/ETO (A/E) fusion gene and expressing the amyloid precursor protein (APP) tended to develop EMI, and had a poor prognosis. In the present study, the relapse-free survival (RFS) time and overall survival (OS) time were significantly lower in patients with EMI. The results demonstrated that the EMI incidence was significantly higher (P<0.05), while the RFS and OS rates were significantly lower (P<0.05), in patients with high APP expression. Kasumi-1 cells, which are A/E⁺, and the APP gene were used as the in vitro cell model to detect the mechanism of action in detail. Following the knockdown of APP expression, cell migration was significantly reduced (P<0.05). Furthermore, western blotting demonstrated that the protein expression of phosphorylated extracellular-signal-regulated kinase (p-ERK), matrix metalloproteinase-2 (MMP-2) and c-Myc was markedly reduced following interference of APP, while the expression of CXCR4 and MMP-9 was not altered. Kasumi-1 cells were co-cultured with p-ERK or c-Myc inhibitors and demonstrated that the APP/p-ERK/c-Myc/MMP-2 pathway was involved in signal transduction and regulation of cell migration. MicroRNA-144 (miR-144) mimics and transfected Kasumi-1 cells were generated. Reverse transcription-quantitative polymerase chain reaction and western blotting demonstrated that miR-144 was a negative regulator of APP. Taken together, the findings of the present study suggest that miR-144 negatively targets the APP gene and regulates cell migration via the APP/p-ERK/c-Myc/MMP-2 pathway.

Nuclear connectin novex-3 promotes proliferation of hypoxic foetal cardiomyocytes

Loss of cardiomyocyte proliferative capacity after birth is a major obstacle for therapeutic heart regeneration in adult mammals. We and others have recently shown the importance of hypoxic in utero environments for active foetal cardiomyocyte proliferation. Here, we report the unexpected expression of novex-3, the short splice variant of the giant sarcomeric protein connectin (titin), in the cardiomyocyte nucleus specifically during the hypoxic foetal stage in mice. This nuclear localisation appeared to be regulated by the N-terminal region of novex-3, which contains the nuclear localisation signal. Importantly, the nuclear expression of novex-3 in hypoxic foetal cardiomyocytes was repressed at the postnatal stage following the onset of breathing and the resulting elevation of oxygen tension, whereas the sarcomeric expression remained unchanged. Novex-3 knockdown in foetal cardiomyocytes repressed cell cycle-promoting genes and proliferation, whereas novex-3 overexpression enhanced proliferation. Mechanical analysis by atomic force microscopy and microneedle-based tensile tests demonstrated that novex-3 expression in hypoxic foetal cardiomyocytes contributes to the elasticity/compliance of the nucleus at interphase and facilitates proliferation, by promoting phosphorylation-induced disassembly of multimer structures of nuclear lamins. We propose that novex-3 has a previously unrecognised role in promoting cardiomyocyte proliferation specifically at the hypoxic foetal stage.

Progress in the understanding of the etiology and predictability of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of fetus to reach its growth potential for various reasons, leading to multiple perinatal complications and adult diseases of fetal origins. Shallow extravillous trophoblast (EVT) invasion-induced placental insufficiency and placental dysfunction are considered the main reasons for idiopathic FGR. In this review, first we discuss the major characteristics of anti-angiogenic state and the pro-inflammatory bias in FGR. We then elaborate major abnormalities in placental insufficiency at molecular levels, including the interaction between decidual leukocytes and EVT, alteration of miRNA expression and imprinted gene expression pattern in FGR. Finally, we review current animal models used in FGR, an experimental intervention based on animal models and the progress of predictive biomarker studies in FGR.Free Chinese abstract: A Chinese translation of this abstract is freely available at http://www.reproduction-online.org/content/153/6/R215/suppl/DC1.

Peptidome analysis of amniotic fluid from pregnancies with preeclampsia

Preeclampsia (PE), a life-threatening, complicated pregnancy-associated disease, has recently become a research focus in obstetrics. However, the peptidome of the amniotic fluid in PE patients has rarely been investigated. The present study used peptidomic profiling to perform a comparative analysis of human amniotic fluid between normal and PE pregnancies. Centrifugal ultrafiltration and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was combined with isotopomeric dimethyl labels to gain a deeper understanding of the role of proteins and the peptidome in the onset of PE. Following ultrafiltration and LC-MS/MS, 352 peptides were identified. Of these, 23 peptides were observed to be significantly differentially expressed (6 downregulated and 17 upregulated; P<0.05). Using Gene Ontology and Blastp analyses, the functions and biological activities of these 23 peptides were identified and revealed to include autophagy, signal transduction, receptor activity, enzymatic activity and nucleic acid binding. In addition, a bibliographic search revealed that some of the identified peptides, including Titin, are crucial to the pathogenesis underlying PE. The present study identified 23 peptides expressed at significantly different levels in the amniotic fluid of PE and normal pregnancies. A comprehensive peptidome analysis is more efficient than a simple biomarker analysis at revealing deficiencies and improving the detection rate in diseases. These analyses therefore provide a substantial advantage in applications aimed at the discovery of disease-specific biomarkers.

CsA Promotes XIST Expression to Regulate Human Trophoblast Cells Proliferation and Invasion Through miR-144/Titin Axis

In our previous study, we revealed that Cyclosporin A (CsA) could inhibit miR-144 expression to regulate proliferation and invasion of human trophoblast (HT) cells through miR-144 targeting titin. This partially demonstrated the mechanism by which CsA promotes titin expression to increase the vitality of HT cells. However, the mechanism by which CsA inhibits miR-144 expression remains to be investigated. Recently, the interaction between lncRNA and miRNA has been frequently reported to play major role in several biological processes. In the present study, online tools were used to figure out that X-inactive specific transcript (XIST) could interact with miR-144. XIST and miR-144 reciprocally inhibited each other in HT cells; as exhibited by luciferase reporter gene assays, miR-144 bind to XIST by direct targeting. XIST suppressed miR-144 expression to promote titin expression. As exhibited by the Spearman's correlation analysis, in CsA treated HT cells, miR-144 was inversely correlated with titin and XIST, respectively; XIST was positively correlated with titin. Moreover, CsA could promote the proliferation and invasion of HT cells through XIST and the downstream MAPK and MMPs pathway. Taken together, these findings will shed light to the role and mechanism of CsA/XIST/miR-144/titin in regulating HT cells proliferation and invasion. XIST may serve as a potential therapeutic target in HT in the future. J. Cell. Biochem. 118: 2208-2218, 2017. © 2017 Wiley Periodicals, Inc.

Cyclosporine A alters expression of renal microRNAs: New insights into calcineurin inhibitor nephrotoxicity

Calcineurin inhibitors are powerful immunosuppressants that revolutionized organ transplantation. However, non-immune effects of the calcineurin inhibitor, such as cyclosporine A (CsA), have significantly hindered their use. Specifically, nephrotoxicity, which is associated with tubulointerstitial fibrosis, inflammation, and podocyte damage, affects up to half of all transplant patients. Calcineurin is involved in many aspects of kidney development and function; therefore, mechanisms of CsA-induced nephrotoxicity are complex and not yet fully understood. MicroRNAs are short non-coding RNAs that regulate protein-coding RNA expression through post-translational repression of target messenger RNAs. MicroRNA dysregulation is known to be involved in kidney diseases including fibrosis. In this study, we compared the renal microRNA expression profiles between mice that received CsA (20 mg/kg) or vehicle daily for six weeks. The results demonstrate that CsA induces significant changes in renal microRNA expression profile. We used combined criteria of False Discovery Rate (≤0.1), fold change (≥2) and median signal strength (≥50) and identified 76 differencially expressed microRNAs. This approach identified microRNAs previously linked to renal fibrosis that includes let-7d, miR-21, miR-29, miR-30, miR-130, miR-192, and miR-200 as well as microRNAs that have not been reported to be related to nephrotoxicity or immunosuppression. Pathway analysis of microRNA/mRNA changes highlights the Wnt, TGF-β, mTOR, and VEGF pathways. The mRNA expression profiles were compared in the same samples. The change of mRNA and microRNA profiles showed close correlations. To validate that the observed microRNA and mRNA expression level changes in mice kidney tissue were directly related to CsA treatment, the expression change induced by CsA treatment of three microRNAs (miR-21, miR-186, and miR-709) and three mRNAs (BMPR1a, SMURF1 and SMAD7) were compared in HEK293 cell line. A similar trend of expression level change was induced by CsA treatment in all selected microRNAs and mRNAs in the in vitro cell model. These data provide a roadmap for future work to study the role of the known and novel candidate microRNAs in the mechanism of nephrotoxicity and their further therapeutic potential.

Genes, epigenetics and miRNA regulation in the placenta

This text reviews briefly the context in which epigenetics regulate gene expression in trophoblast development and function. It is an attempt to focus on a limited number of recent papers that, according to the author, shed new light on placental development, and constitute possible trails for improving knowledge and women follow-up in pathological pregnancies.

MicroRNA-144 suppresses tumorigenesis and tumor progression of astrocytoma by targeting EZH2

Our previous study demonstrated that enhancer of zeste homolog 2 (EZH2) overexpression may be associated with aggressive tumor progression and poor prognosis in human astrocytoma. The aim of this study was to investigate the underlying mechanisms of EZH2 on astrocytoma tumorigenesis. An online program miRWalk (http://www.umm.uni-heidelberg.de/apps/zmf/mirwalk/) was used to predict possible microRNAs (miRNAs) that might target EZH2 messenger RNA (mRNA). Then the functions of the miRNA-EZH2 mRNA axis in astrocytoma cell proliferation, invasion, and migration were also assessed. We further evaluated the clinical value of the miRNA-EZH2 mRNA axis in astrocytomas. As a result, we identified EZH2 as a target gene of miR-144. In addition, forced expression of miR-144 suppressed astrocytoma cell proliferation, invasion, and migration by down-regulating EZH2. Moreover, miR-144 down-regulation and EZH2 mRNA up-regulation were both significantly associated with advanced World Health Organization grades and low Karnofsky performance status score of astrocytoma patients. Importantly, survival analysis identified the combined expression of miR-144 and EZH2 (miR-144/EZH2) as an independent prognostic factor for overall survival in astrocytoma patients. In conclusion, miR-144 may function as a tumor suppressor by regulating EZH2 expression, and miR-144/EZH2 expression may be a highly sensitive marker for the prognosis in astrocytoma patients.

The oncoprotein HBXIP up-regulates SCG3 through modulating E2F1 and miR-509-3p in hepatoma cells

Hepatitis B X-interacting protein (HBXIP) is an important oncoprotein in hepatocarcinogenesis. Here, we found that the expression levels of HBXIP were positively associated with those of Secretogranin III (SCG3) in clinical hepatocellular carcinoma tissues. We identified that HBXIP up-regulated the expression of SCG3 through modulating both E2F transcription factor 1 (E2F1) and miR-509-3p. HBXIP suppressed miR-509-3p through activating NF-κB. In function, we showed that SCG3 increased the proliferation of hepatoma cells and HBXIP enhanced the proliferation of the cells via SCG3 in vitro and in vivo. Thus, we conclude that HBXIP facilitates the proliferation of hepatoma cells through up-regulating SCG3.