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Extracellular vesicles (EVs) are cell-derived membrane-enclosed structures that deliver biomolecules for intercellular communication. Developing visualization methods to elucidate the spatiotemporal dynamics of EVs' behaviors will facilitate their understanding and translation. With a quantum dot (QD) labeling strategy, a single particle tracking (SPT) platform is proposed here for dissecting the dynamic behaviors of EVs. The interplays between tumor cell-derived small EVs (T-sEVs) and endothelial cells (ECs) are specifically investigated based on this platform. It is revealed that, following a clathrin-mediated endocytosis by ECs, T-sEVs are transported to the perinuclear region in a typical three-stage pattern. Importantly, T-sEVs frequently interact with and finally enter lysosomes, followed by quick release of their carried miRNAs. This study, for the first time, reports the entire process and detailed dynamics of T-sEV transportation and cargo-release in ECs, leading to better understanding of their proangiogenic functions. Additionally, the QD-based SPT technique will help uncover more secrets of sEV-mediated cell-cell communication., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Gestational diabetes mellitus (GDM), the most common medical pregnancy complication, has become a growing problem. More and more studies have shown that microRNAs are closely related to metabolic processes. The purpose of this paper is to investigate the role of up-regulation of miR-199a-5p expression in GDM. We found that miR-199a-5p was significantly up-regulated in the placenta of GDM patients compared with normal pregnant women, and expressed in placental villi. miR-199a-5p can regulate the glucose pathway by inhibiting the expression of methyl CpG-binding protein 2 (MeCP2) and down-regulating canonical transient receptor potential 3 (Trpc3). This suggests that miR-199a-5p may regulate the glucose pathway by regulating methylation levels, leading to the occurrence of GDM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Guan, Cao, Zhang, Wang, Ma and Xia.)

Gestational Diabetes Mellitus (GDM) is a complicated clinical process, and metabolic disorders during pregnancy are closely related to the structure and function of the placenta. The aberrant expression of miRNAs in the placenta may play a role in the occurrence and development of GDM. Analysis of microRNA (miRNA) expression signature in placenta showed that the level of miR-30d-5p was significantly down-regulated in GDM patients. This study aims to explore the possible mechanism of GDM under the regulation of miR-30d-5p. In situ hybridization and qRT-PCR assay showed that miR-30d expression down-regulated in the placentas from GDM patients compared with normal control group. The trophoblast cells proliferation and glucose uptake capacity were increased, the ability of migration and invasion were also improved after inhibiting the function of endogenous mature miR-30d-5p. Bioinformatics analysis and luciferase reporter assays showed that miR-30d-5p binds to the 3'UTR of RAB8A mRNA, resulting in RAB8A suppression. Moreover, the down-regulation of RAB8A could attenuate the increase in trophoblast cell proliferation, migration, invasion and glucose uptake induced by miR-30d-5p functional inhibitor. These data imply that miR-30d-5p expression is down-regulated in placental tissue from GDM patients and affects trophoblast cell functions by targeting RAB8A, which may provide new insight into the pathogenesis of GDM., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Missed abortion (MA) is a common disease in obstetrics and gynecology. More and more studies have focused on the relationship between miRNAs and pregnancy maintenance and its related diseases. The aim of this article is to explore the relationship between miRNA and MA. The expression of miR-98 were detected by in situ hybridization and real-time PCR. Cell proliferation, activity and migration were measured via Edu, MTT, and transwell assays. The target genes of miR-98 are identified by dual-luciferase activity assay. And the expression levels of target genes were determined by Western blot, real-time PCR and immunohistochemistry. miR-98 was significantly up-regulated in placental villi from over 35 years old MA patients compared with the age-matched normal pregnant women. Up-regulation of miR-98 suppressed the proliferation, activity and migration of the human trophoblast HTR-8/SVneo cell in vitro. miR-98 could bind to GDF6 and FAPP2 mRNA 3'-UTR and negatively regulate their expression. The downregulation of miR-98 promoted cell proliferation, then knockdown of GDF6 or FAPP2 inhibited miR-98-mediated cell proliferation. GDF6 and FAPP2 expression in the placental villi from MA patients were decreased compared to normal placental tissues. The expression of miR-98 in MA had an opposite relationship with the expression of GDF6 and FAPP2. Overexpression of miR-98 is associated with the occurrence of MA. miR-98 prevents proliferation, viability and migration of trophoblast cells partially through targeting GDF6 and FAPP2.

Gestational diabetes mellitus (GDM) is a disease that changes the function of microvascular of placenta. MicroRNA (miRNA) expression in placenta may contribute to the pathogenesis of GDM. Here, we evaluate the role and function of miR-29b in the development of GDM. This study discovered that miR-29b expression was lower in placentas derived from patients with GDM than that in control placentas. MiR-29b over-expression inhibited cell growth and migration, and miR-29b knockdown promoted cell migration. Then we predicted and confirmed that HIF3A was a direct target of miR-29b with two specific binding sites at the recognition sequences of miR-29b in 3'-UTR of HIF3A mRNA, which was negatively correlated with miR-29b expression level. The up-regulation of HIF3A partially antagonized the inhibitory effect of miR-29b over-expression on cell growth and migration. The enhancement of cell migration induced by miR-29b knockdown was attenuated by down-regulating HIF3A . These results imply that down-regulation of miR-29b may be related with the development of GDM partially via increasing the expression of HIF3A , which may provide a new insight for the mechanism of GDM., (Copyright © 2020 Sun, Tian, Zhang, Hu, Guan, Ma and Xia.)

Recurrent spontaneous abortion (RSA) is a common health problem that affects 1-5% of women in reproductive age. Plenty of studies have indicated that microRNAs (miRNAs) are involved in the occurrence of miscarriage. MiR-93 has a wide range of functions in mammalian tissues and plays an important role in many diseases especially for cancers. However, it remains unknown whether miR-93 is associated with human RSA. In this report, clinical samples revealed that miR-93 expression was significantly elevated in the villi tissues of RSA patients. Upregulation of miR-93 inhibited human trophoblast cells HTR-8/SVneo cell proliferation, migration, and invasiveness, but promoted cell apoptosis in vitro. Conversely, the downregulation of miR-93 reversed these effects. Bcl-2 like protein 2 (BCL2L2), a potential target gene of miR-93, was inversely correlated with miR-93 expression in the villi of clinical samples. Furthermore, the luciferase reporter system demonstrated that miR-93 directly downregulated the expression of BCL2L2 by binding a specific sequence of its 3'-untranslated region (3'UTR). Collectively, these data strongly suggest that miR-93 regulates trophoblast cell proliferation, migration, invasive, and apoptosis by targeting BCL2L2 expression and is involved in the pathogenesis of RSA.

MicroRNAs (miRNAs) regulate diverse cellular processes such as cell differentiation, proliferation and apoptosis. Mutation in miRNAs results in various pathological conditions such as inflammation, viral infections, neurodegeneration, and autoimmunity. We have evaluated the association of miR-423 rs6505162C>A and rs8067576 A>T among patients with recurrent pregnancy loss (RPL) and controls from North China. Our study found that one SNP rs6505162C>A in miR-423 coding region was associated with the increase risk of humanunexplained RPL (URPL), but no differences were found in another SNP rs8067576 A>T. However, in two-locus haplotype analysis, miR-423-CC/TT haplotype was associated with an increased risk of URPL. The level of mature miR-423 was obviously down-regulated in cells transfected with miR-423-CC/TT haplotype. miR-423-CC/TT haplotype inhibited HTR-8/SVneo cells proliferation and migration and promoted cells apoptosis. Further experiments identified that mesoderm development candidate 1 (MESDC1) was a functionally relevant target of miR-423, and its expression was reversely regulated by miR-423. More importantly, dual-luciferase assay indicated miR-423-CC/TT haplotype decreasing miR-423 expression, could up-regulate MESDC1 expression. Collectively, our data suggest that miR-423-CC/TT haplotype in pre-miR-423 may aggravate the risk of developing URPL by influencing the level of mature miR-423 and its target gene MESDC1., (Copyright © 2018. Published by Elsevier Inc.)

Venous malformations (VMs) are characterized by ectatic and tortuous venous channels with decreased perivascular cell coverage. Recent studies have discovered that miR-145 plays a critical role in amounts of vascular diseases through regulating the differentiation and phenotype of vascular smooth muscle cells (VSMCs). However, the potential roles of miR-145 in VMs remain unknown. In this study, 21 samples of VMs without treatment history, and 10 samples of healthy donor skin, were collected to evaluate the expression level of TGF-β, miR-145, and α-SMA by immunohistochemistry, in situ hybridization, and real-time polymerase chain reaction (PCR). Subsequently, their correlations were analyzed using the Spearman rank correlation test. In vitro studies were performed using human umbilical vein endothelial cells (HUVECs). The results showed that miR-145 was significantly downregulated in VMs compared with normal skin tissues, accompanied by a synchronously decreased TGF-β expression level and perivascular α-SMA + cell coverage. Correlation analysis revealed that miR-145 expression was positively correlated with TGF-β expression and perivascular α-SMA + cell coverage in VMs. In addition, TGF-β, miR-145, and α-SMA were concurrently increased in the tissues of VMs treated with bleomycin A5. More importantly, in vitro studies revealed that both recombinant human TGF-β and bleomycin A5 could significantly upregulate TGF-β and miR-145 expression in HUVECs with the similar increasing tendency. In summary, our present study unmasked the downregulation of miR-145 in VMs, possibly induced by TGF-β depression and closely correlated with disorganized vessels. Moreover, miR-145 may be involved in the sclerotherapy of VMs and possess the target potential., (Copyright © 2017 Elsevier B.V. All rights reserved.)

MiR-98 expression was up-regulated in kidney in response to early diabetic nephropathy in mouse and down-regulated in muscle in type 2 diabetes in human. However, the expression prolife and functional role of miR-98 in human gestational diabetes mellitus (GDM) remained unclear. Here, we investigated its expression and function in placental tissues from GDM patients and the possible molecular mechanisms. The results showed that miR-98 was up-regulated in placentas from GDM patients compared with normal placentas. MiR-98 over-expression increased global DNA methylational level and miR-98 knockdown reduced global DNA methylational level. Further investigation revealed that miR-98 could inhibit Mecp2 expression by binding the 3'-untranslated region (UTR) of methyl CpG binding protein 2 (Mecp2), and then led to the expression dysregulation of canonical transient receptor potential 3 (Trpc3), a glucose uptake related gene. More importantly, in vivo analysis found that the expression level of Mecp2 and Trpc3 in placental tissues from GDM patients, relative to the increase of miR-98, was diminished, especially for GDM patients over the age of 35 years. Collectively, up-regulation of miR-98 in the placental tissues of human GDM is linked to the global DNA methylation via targeting Mecp2, which may imply a novel regulatory mechanism in GDM.

MicroRNA-10a (miR-10a) has a wide range of functions in nearly all mammalian tissues and is involved in the occurrence of many diseases. However, it remains unknown whether miR-10a is associated with human recurrent spontaneous abortion (RSA). In this study, we found that rs3809783 A > T in miR-10a coding region was significantly associated with the increase of the risk of human unexplained RSA (URSA) acquisition in a Han-Chinese population. The T allele of rs3809783 hindered the production of mature miR-10a. A to T substitution in miR-10a rs3809783 repressed cell proliferation and migratory capacity. Further investigation discovered that Bcl-2-interacting mediator (Bim) was the functional target of miR-10a and inversely regulated Bim expression. Dual-luciferase assay indicated that A allele in miR-10a rs3809783 could more effectively suppress Bim expression than T allele. In addition, A to T substitution in miR-10a rs3809783 attenuated the sensibility of cells to progesterone and its antagonist mifepristone. Collectively, our data suggest that rs3809783 A > T in pri-miR-10a may be conductive to the genetic predisposition to RSA by disrupting the production of mature miR-10a and reinforcing the expression of Bim.

Although the relationship between polymorphisms in microRNAs (miRNAs) and recurrent pregnancy loss (RPL) has been studied, there is very little data available in the literature. In the present study, we scanned 55 potentially functional polymorphisms in the miRNA coding region in Chinese women with unexplained RPL (URPL; no. 2011-10). The rs6505162 C>A in the MIR423 coding region was found to be significantly associated with the occurrence of human URPL. The rare A allele contributed to an increase in the expression of mature MIR423. C to A substitution in the polymorphism rs6505162 in pre-MIR423 repressed cell proliferation and migratory capacity. Further investigations showed that MIR423 could inversely regulate the expression of proliferation-associated 2 group 4 (PA2G4) by binding the 3'-UTR of PA2G4. Dual-luciferase assay indicated that the A allele in the polymorphism rs6505162 could more effectively suppress the expression of PA2G4 than the C allele could. Collectively, the present data suggest that rs6505162 C>A in pre-MIR423 may contribute to the genetic predisposition to RPL by disrupting the production of mature MIR423 and its target gene, which consequently interferes with MIR423 functioning., (© 2015 Society for Reproduction and Fertility.)

Background: To study the role of miR-143 during embryo implantation in rat., Methods: MiR-143 expression in rat early pregnancy was detected by Northern blot. The relation between miR-143 and Lifr predicted and confirmed by bioinformatics method, dual-luciferase activity assay, Western blot and immunohistochemistry. The role of miR-143 was detected by MTS, Edu and ranswell chamber assays., Results: The expression level of miR-143 on gestation day 5-8 (g.d. 5-8) was higher than on g.d. 3-4 in uteri of pregnant rat. MiR-143 was mainly localized in the superficial stroma/primary decidual zone, luminal and glandular epithelia. The expression of miR-143 was not significantly influenced by pseudopregnancy, but the activation of delayed implantation and experimentally induced decidualization significantly promoted miR-143 expression. Over-expression of miR-143 in human endometrial stromal cells (ESCs) inhibited cell proliferation, migration and invasion. Knockdown of miR-143 promoted cell proliferation and invasion. The results of recombinant luciferase reporters showed that miR-143 could bind to the 3¢-untranslated region (UTR) of leukemia inhibitory factor receptor (Lifr) to inhibit Lifr translation., Conclusions: Uterine miR-143 may be involved in the successful pregnancy, especially during the process of blastocyst implantation through regulating Lifr., General Significance: This study may have the potential to provide new insights into the understanding of miR-143 function during embryo implantation., (Copyright © 2014 Elsevier B.V. All rights reserved.)

MicroRNAs (miRNAs) are short non-coding RNAs which modulate gene expression by binding to complementary segments present in the 3'UTR of the mRNAs of protein coding genes. MiRNAs play very important roles in maintaining normal human body physiology conditions, meanwhile, abnormal miRNA expressions have been found related to many human diseases spanning from psychiatric disorders to malignant cancers. Recently, emerging reports have indicated that disturbed miRNAs expression contributed to the pathogenesis of recurrent pregnancy loss (RPL). In this study, we identified a new mutation site (+29A>G, position relative to pre-miR-125a) by scanning pri-miR-125a coding region in 389 Chinese Han RPL patients. This site was co-existed with two polymorphisms (rs12976445 and rs41275794) in patients heterogeneously and changed the predicted secondary structures of pri-miR-125a. Subsequent in vitro analysis indicated that the A>G mutation reduced mature miR-125a expression, and further led to less efficient inhibition of verified target genes. Functional analysis showed that mutant pri-mir-125a can enhance endometrial stromal cells (ESCs) invasive capacity and increase the sensitivity of ESCs cells to mifepristone. Moreover, we further analyzed the possible molecular mechanism by RIP-chip assay and found that mutant pri-mir-125a disturbed the expression of miR-125a targetome, the functions of which includes embryonic development, cell proliferation, migration and invasion. These data suggest that A>G mutation in pri-miR-125a coding region contributes to the genetic predisposition to RPL by disordering the production of miR-125a, which consequently meddled in gene regulatory network between mir-125a and mRNA.

MiR-185 expression has been associated with many cancers. However, the roles of miR-185 in human breast cancer remain elusive. Here, we found that miR-185 expression was decreased in human breast cancer tissues compared with healthy tissue controls. Up-regulation of miR-185 inhibited breast cancer cell proliferation and invasion and vice versa. MiR-185 was shown to bind to the 3′-untranslated region (UTR) of vascular endothelial growth factor a (Vegfa), and a significant inverse correlation was found between miR-185 and Vegfa. Vegfa overexpression partially restored the inhibition of cell proliferation and invasion that was induced by miR-185, and vice versa. Additionally, Vegfa expression was found to be high in human breast cancer tissues. Thus, miR-185-mediated Vegfa targeting may be involved in breast cancer formation.

MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate post-transcriptional gene expression by base pairing with partially complementary sequences within target messenger RNAs (mRNAs). Although the target genes and the precise biological functions of individual miRNAs remain largely unknown, miRNAs have been implicated in diverse biological processes, including both normal and pathological states. As a single stranded mRNA can be directly targeted by multiple miRNAs, and as the target sites may exist in the 3'-untranslated region (UTR), 5'-UTR, or the coding regions, it is essential to develop an effective method to identify the full-scale miRNA regulatory pattern of each particular gene. In this study, we employed a biochemical approach to identify the miRNA profiles that regulate the expression of embryonic ectoderm development (EED) protein by using anti-PABPC1 ribonucleoprotein (RNP) co-immunoprecipitation (Co-IP). The full length EED mRNA was subcloned into an expression vector and transiently transfected into a Flag-PABPC1 stable expression cell line. Subsequent to cross-linking and an anti-Flag Co-IP, the miRNAs that directly targeted EED were identified. We found that the best time point to distinguish the positive miRNAs from the background was 18 hours after the plasmid transfection. As expected, the miRNAs that directly target EED were found to interact with EED mRNA through the miRNA-induced silencing complex (miRISC). Meanwhile, the EED mRNA was bound by Flag-PABPC1. This method depends on the integrity of the miRISC complex and achieves greater efficiency when ultraviolet irradiation is used for the process of cross-linking. By using anti-PABPC1 RIP, we identified EED to be a new target gene of miR-16; a finding further confirmed using a dual-luciferase assay. In summary, our data indicate that anti-PABPC1 RIP is a validated and direct biochemical method to provide data about specific miRNA-mRNA interactions, as well as global miRNA patterns regulating the mRNAs.

Embryo implantation is a complex initial step in establishment of a successful pregnancy. Many mRNAs have been shown to be differentially expressed in the rat uterus during embryo implantation. However, the expression profiles of microRNAs (miRNAs), a key post-transcriptional regulator of gene expression, in the rat uterus between the pre-receptive and receptive phases are still unknown. Here, an miRNA microarray was used to examine differential expression of miRNAs in the rat uterus between the pre-receptive and receptive phases. Twenty-eight miRNAs were up-regulated and 29 miRNAs were down-regulated at least twofold during the receptive phase in rat uterus; these results were confirmed by Northern blotting. miR-29a was only highly expressed in rat uterus during the implantation period, and activation of delayed implantation and artificial decidualization enhanced the miR-29a level. Further investigation revealed that both the pro-apoptotic factor genes Bak1 and Bmf and the anti-apoptotic factor gene Bcl-w are targets of miR-29a. There was weak binding between miR-29a and the 3' UTR of the anti-apoptotic factor gene Mcl1. Over-expression of miR-29a inhibited the late apoptosis of endometrial stromal cells, which may be due to the stronger binding capacity between miR-29a and the 3' UTR of pro-apoptotic factors than that between miR-29a and the 3' UTR of anti-apoptotic factors. Collectively, miR-29a plays an important role during embryo implantation by regulating both pro-apoptotic and anti-apoptotic factors. miR-29a may predominantly bind pro-apoptotic factors, leading to inhibition of cell apoptosis., (© 2014 FEBS.)

In a previous study, via microRNA microarray analysis we found that miR-98 is differentially expressed in rat uteri during the peri-implantation period (unpublished data). However, the role of miR-98 in rat embryo implantation remains elusive. Here, we found that the level of miR-98 is lower on day 5 and 6 of gestation (g.d. 5-6) than that on g.d. 3-4 and g.d. 7-8 in rat. MiR-98 expression is significantly decreased by delayed implantation. Down-regulation of miR-98 promotes ESC proliferation and inhibits apoptosis. Up-regulation of miR-98 displays opposite effects. Further investigation revealed that miR-98 can bind to the 3'-untranslated region (3'-UTR) of B-cell lymphoma-extra large (Bcl-xl) to inhibit Bcl-xl translation. Collectively, down-regulation of miR-98 in rat uterus during the receptive phase is linked to the increase of cell proliferation via targeting Bcl-xl., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

MiR199a was found to be differentially expressed in rat uteri between the prereceptive and receptive phase via microRNA (miRNA) microarray analysis in our previous study. However, the role of miR199a in rat embryo implantation remained unknown. In the study, northern blot results showed that the expression levels of miR199a were higher on gestation days 5 and 6 (g.d.5-6) in rat uteri than on g.d.3-4 and g.d.7-8. In situ localization of miR199a in rat uteri showed that miR199a was mainly localized in the stroma or decidua. The expression of miR199a was not significantly different in the uteri of pseudopregnant rats and evidently increased in the uteri of rats subjected to activation of delayed implantation and experimentally induced decidualization. Treatment with 17β-estradiol or both 17β-estradiol and progesterone significantly diminished miR199a levels. Gain of function of miR199a in endometrial stromal cells isolated from rat uteri inhibited cell proliferation and promoted cell apoptosis. Loss of function of miR199a displayed opposite roles on cell proliferation and apoptosis. Further investigation uncovered a significant inverse association between the expression of miR199a and growth factor receptor-bound protein 10 (Grb10), an imprinted gene, and miR199a could bind to the 3'UTR of Grb10 to inhibit Grb10 translation. In addition, in vivo analysis found that the immunostaining of GRB10 was attenuated in the stroma or decidua from g.d.4 to 6, contrary to the enhancement of miR199a. Collectively, upregulation of miR199a in rat uterus during the receptive phase is regulated by blastocyst activation and uterine decidualization. Enforced miR199a expression suppresses cell proliferation partially through targeting Grb10.

Increasing evidence shows that single nucleotide polymorphisms (SNPs) or mutations in microRNAs (miRNAs) sequence may affect the processing and function of miRNAs and participate in the occurrence of diseases. Although many SNPs of miRNAs were found, their functions in the pathological process of nerve cells were only just emerging. In the present study, the effect of the SNP of one neuronal miRNA, miR-124, on miRNA biogenesis and human genetic disease was investigated using in vitro cell line model and Alzheimer's disease (AD) in the Mongolian population. Bioinformatics prediction showed that a common G/C polymorphism designated rs531564 was found in the pri-miR-124 and the G allele changed the formation of a ring-shaped structure in the predicted secondary structure of the pri-miRNA for miR-124-1. Northern blot and real-time PCR analysis showed that the amount of mature miR-124 from the C/G heterozygosity of rs531564 was increased compared with the CC or GG homozygosity of rs531564. The expression of mature miR-124 from GG homozygosity was also higher than that from CC homozygosity. But in an association study of AD patients and controls, neither genotype nor allele distribution difference was found in AD patients compared with controls. Collectively, the present study is the first to evaluate the relationship between miR-124 and AD in the Mongolian population. SNP rs531564 of miR-124 may not represent a risk factor in the development of AD among Mongolian population., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

MiR-206 was involved in a series of cellular activities, such as the growth and development of skeletal muscle and the tumorigenesis. MiR-206 was characterized previously as a differentially expressed gene in sodium arsenite (SA)-induced neural tube defects (NTDs) in chick embryos via miRNA microarray analysis. However, the role of miR-206 in the pathological process of nerve cells remained elusive. In this study we found differential expression of miR-206 in SA-treated chick embryos by Northern blot analysis. Ectopic expression of miR-206 inhibited cell proliferation, and promoted cell apoptosis in U343 and SK-N-SH cell by using MTT, Edu Apollo assay and Flow cytometry analysis. Further investigation revealed that miR-206 can interact with 3'-untranslated region (UTR) of Otx2. MiR-206 mimics down-regulated the endogeneous Otx2 expression, whereas the miR-206 inhibitor obviously up-regulated the expression of Otx2. These findings indicate that overexpression of miR-206 promotes cell apoptosis and low expression of miR-206 inhibits cell apoptosis. Otx2 may play an important role in the process of miR-206-mediated cell apoptosis., (Copyright © 2012 S. Karger AG, Basel.)

Background: MicroRNA-101 (miR-101) expression is negatively associated with tumor growth and blood vessel formation in several solid epithelial cancers. However, the role of miR-101 in human breast cancer remains elusive., Results: MiR-101 was significantly decreased in different subtypes of human breast cancer tissues compared with that in adjacent normal breast tissues (P<0.01). Up-regulation of miR-101 inhibited cell proliferation, migration and invasion, and promoted cell apoptosis in ER alpha-positive and ER alpha-negative breast cancer cells and normal breast cells. Down-regulation of miR-101 displayed opposite effects on cell growth and metastasis. Further investigation revealed a significant inverse correlation between the expression of miR-101 and Stathmin1 (Stmn1), and miR-101 could bind to the 3'-untranslated region (UTR) of Stmn1 to inhibit Stmn1 translation. The inhibition of cell growth and metastasis induced by up-regulation of miR-101 was partially restored by overexpression of Stmn1. Knockdown of Stmn1 attenuates the down-regulation of miR-101-mediated enhancement of cell growth and metastasis. More importantly, in vivo analysis found that Stmn1 mRNA and protein level in different subtypes of human breast cancer tissues, contrary to the down-regulation of miR-101, were significantly elevated., Conclusions: This study demonstrates that down-regulation of miR-101 in different subtypes of human breast cancer tissues is linked to the increase of cellular proliferation and invasiveness via targeting Stmn1, which highlights novel regulatory mechanism in breast cancer and may provide valuable clues for the future clinical diagnosis of breast cancer.

Although there are plenty of evidence that single-nucleotide polymorphisms (SNPs) that fall within coding sequences of genes are involved in recurrent pregnancy loss (RPL), it is still unknown whether the polymorphisms in microRNAs (miRNAs) are related with RPL. In this study, we established this kind of association by confirming significant differences in genotype distribution of rs41275794 (P= 0.0005) and rs12976445 (P= 0.001) within the pri-miR-125a in 217 Han Chinese patients of RPL compared with 431 controls. Based on this observation, two-locus haplotypes were constructed and the A-T haplotype was found to be associated with an increased risk of RPL (OR=2.84, 95%C.I. 1.98-4.07, P=0.0000000057). Further analysis showed that the levels of pre- and mature- miR-125a were down-regulated in the cells transfected with the A-T haplotype, which was consistent with in vivo detection that the level of mature miR-125a was lower in 30 pregnant women with A-T haplotype than that with G-C haplotype. During in vitro RNA processing assays, we found a similar decrease in the amount of pre-miR-125a and decline in binding capacity of nuclear factors to pri-miR-125a with A-T haplotype. More importantly, the reduction in miR-125a, as a consequence of A-T haplotype, further led to less efficient inhibition of target genes, LIFR and ERBB2, which play important roles in the embryo implantation and decidualization. Thus, our data collectively suggest that two common polymorphisms in pre-miR-125a might contribute to the genetic predisposition to RPL by disrupting the production of miR-125a, which consequently interfered in the expression and function of target genes of miR-125a.

Objective: The objective of the study was to investigate the expression and regulation of polycomb group (PcG) proteins in human neural tube defects (NTDs)., Study Design: PcG proteins in human NTD fetuses and age-matched controls were detected by Western blot. The relation between PcG proteins and microribonucleic acids was predicted and confirmed by the bioinformatics method, real-time polymerase chain reaction (PCR), dual-luciferase activity assay, and Western blot. The trimethyl condition of histone H3 Lys27 (H3K27) was detected by immunohistochemical and immunofluorescence., Results: Embryonic ectoderm development protein (EED) was differentially detected in placenta, cerebral cortex, and spinal cord from NTDs and age-matched controls. MiR-30b can interact with 3'-untranslated region (UTR) of Eed and regulate endogenous EED expression in neural tissues. In addition, we found an inverse relationship between the miR-30b expression and the amount of trimethyl H3K27., Conclusion: Differential expression of EED exists in the nerves system in human NTDs and that is regulated by miR-30b., (Copyright © 2011. Published by Mosby, Inc.)

The implantation process is complex, requiring reciprocal interactions between implantation-competent blastocysts and the receptive uterus. There were reports to show that some microRNAs (miRNAs) may play a key role during embryo implantation in mouse. However, the miR-320 expression profiles in the rat uterus during peri-implantation are unknown. In the present study, we found that the expression level of miR-320 was lower on day 5 of gestation (g.d. 5) in rats than g.d.3 and g.d.4 and restored gradually from g.d.6. MiR-320 was specifically localized in glandular and luminal epithelia and decidua. The expression of miR-320 was not significantly different in the pseudopregnant uterus and decreased in the uteri of rats subjected to activation of delayed implantation. Artificial decidualization and treatment with progesterone increased the miR-320 expression. Thus, miR-320 was differentially expressed in the rat uterus during implantation. The expression level was affected by active blastocysts and decidualization during the window of implantation. Steroid hormones, progesterone stimulated miR-320 expression.

Mammalian embryonic implantation requires reciprocal interactions between implantation-competent blastocysts and a receptive uterus. Some microRNAs might play a key role during embryo implantation in the mouse, but the let-7a expression profiles in the rat uterus during peri-implantation are unknown. In the study, the expression of let-7a in the uterus during early pregnancy, pseudopregnancy, artificial decidualization and activation of delayed implantation was detected by Northern blotting and in situ hybridization. The effect of steroid hormones on let-7a expression was also detected by Northern blotting and in situ hybridization. Here, we found that the expression level of let-7a was higher on gestation day 6-7 (g.d. 6-7) in rats than on g.d.4-5 and g.d.8-9. Let-7a was specifically localized in glandular and luminal epithelia and decidua. The expression of let-7a was not significantly different in the pseudopregnant uterus and increased significantly in the uteri of rats subjected to artificial decidualization and activation of delayed implantation. Treatment with estradiol-17beta or progesterone significantly increased let-7a expression. Thus, let-7a expression was significantly induced by the process of embryo invasion, and this increased expression level was mainly induced by active blastocysts and decidualization during the window of implantation, implying that let-7a may participate in endometrial decidualization. Steroid hormones, estradiol-17beta or progesterone stimulated let-7a expression.

The process of folliculogenesis requires a tightly regulated series of gene expression that are a pre-requisite to the development of ovarian follicle. Among these genes, follicle-stimulating hormone (FSH) is notable for its dual role in development of follicles as well as proliferation and differentiation of granulosa cells. The post-transcriptional expression of these genes is under the control of microRNAs (miRNAs), a class of small, endogenous RNAs that negatively impact gene expression. This study was carried out to determine the role of several miRNAs including mir-143, let-7a, mir-125b, let-7b, let-7c, mir-21 in follicular development in the mouse. The expression of these RNAs was very low in primordial follicles but these became readily detectable in the granulosa cells of primary, secondary and antral follicles. We show that this expression of some miRNAs (mir-143, let-7a, mir-15b) is under negative control of FSH. Together, these findings suggest that FSH regulates folliculogenesis by a novel pathway of miRNAs.

Background: MicroRNAs (miRNAs) are small noncoding RNAs whose function as modulators of gene expression is crucial for the proper control of cell growth. Although many microRNAs were found to express in central nervous system (CNS), the role of the regulatory networks in which they are involved and their function in the pathological process of nerve cells are only just emerging. In the present study, the possible mechanisms by which one neuronal miRNAs, miR-125b, affected the growth of nervous cells were investigated using in vitro cell line model., Methods: The expression pattern of miR-125b in ATRA-treated human glioma cell lines was detected by Northern blotting and in situ localization. The effect of miR-125b on the proliferation and apoptosis of human glioma cells was analyzed by MTS assay, TUNEL and Flow cytometry analysis. In addition, the identification of target gene of miR-125b was studied by dual-luciferase activity assay and Immunoblot Analysis., Results: We found differential expression of miR-125b in 1.0 microM all-trans-retinoic acid (ATRA)-treated human glioma cell lines. Up-regulation of miR-125b partially restored cell viability and inhibited cell apoptosis in U343 cells treated by ATRA. Down-regulation of miR-125b decreased human glioma cells proliferation and enhanced the sensitivity of human glioma cells to ATRA-induced apoptosis. In addition, we found an inverse relationship between the expression of miR-125b and the cell apoptosis-related protein Bcl-2 modifying factor (Bmf), and miR-125b can interact with 3'-untranslated region (UTR) of Bmf., Conclusion: These findings indicate that overexpression of miR-125b promotes human glioma cell proliferation and inhibits ATRA-induced cell apoptosis and low expression of miR-125b sensitizes cells to ATRA-induced apoptosis. BMF may play an important role in the process of miR-125b influencing cell apoptosis., (Copyright 2009 S. Karger AG, Basel.)