Talk:Molecular Development - microRNA

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Cite this page: Hill, M.A. (2021, December 2) Embryology Molecular Development - microRNA. Retrieved from

PMID 22866204

  • miR-1/miR-133 Cardiovascular Development - regulators of muscle proliferation and differentiation both in cardiac and skeletal muscles
  • miR-143/miR-145 in Vascular Smooth Muscle Biology
  • miR-126 as a Regulator of VEGF Signaling in the Endothelium
  • miR-17~92 Cluster as Intrinsic Antiangiogenic miRs in Endothelium - highly expressed in human endothelial cells and plays a critical role as a negative regulator of angiogenesis.
  • miR-132, miR-126, miR-296, miR-145, and miR-92a have been shown to play pro- and antiangiogenic roles in the vasculature of both endothelial cells and perivascular cells.


Biochem Soc Trans. 2017 Oct 15;45(5):1117-1124. doi: 10.1042/BST20170033. Epub 2017 Sep 22. Long and small noncoding RNAs during oocyte-to-embryo transition in mammals. Svoboda P1. Author information Abstract Oocyte-to-embryo transition is a process during which an oocyte ovulates, is fertilized, and becomes a developing embryo. It involves the first major genome reprogramming event in life of an organism where gene expression, which gave rise to a differentiated oocyte, is remodeled in order to establish totipotency in blastomeres of an early embryo. This remodeling involves replacement of maternal RNAs with zygotic RNAs through maternal RNA degradation and zygotic genome activation. This review is focused on expression and function of long noncoding RNAs (lncRNAs) and small RNAs during oocyte-to-embryo transition in mammals. LncRNAs are an assorted rapidly evolving collection of RNAs, which have no apparent protein-coding capacity. Their biogenesis is similar to mRNAs including transcriptional control and post-transcriptional processing. Diverse molecular and biological roles were assigned to lncRNAs although most of them probably did not acquire a detectable biological role. Since some lncRNAs serve as precursors for small noncoding regulatory RNAs in RNA silencing pathways, both types of noncoding RNA are reviewed together. KEYWORDS: LTR; RNAi; lncRNA; oocyte; siRNA; zygote PMID: 28939692 DOI: 10.1042/BST20170033

MicroRNA-194 Regulates the Development and Differentiation of Sensory Patches and Statoacoustic Ganglion of Inner Ear by Fgf4

Med Sci Monit. 2018 Mar 23;24:1712-1723.

Cao H1,2, Shi J1, Du J3, Chen K1, Dong C4, Jiang D5, Jiang H4.


BACKGROUND MicroRNA 194 is involved in the differentiation of various types of cells, such as adipose derived stem cells, human embryonic stem cells, and bone marrow mesenchymal stem cells. Previously, we found that miR-194 was highly expressed in the inner ear sensory patch and neurons in mice embryos. However, the role of miR-194 in the development of the inner ear and its underlying mechanism have not been elucidated yet. MATERIAL AND METHODS The expression level of miR-194 has been altered by using antisense morpholino oligonucleotides (MO) and synthesized miRNAs in zebrafish. RESULTS We found that miR-194 was vastly expressed in the inner ear and central nervous system (CNS) in zebrafish. Loss of function of miR-194 could strongly affected the development of zebrafish embryos, including delayed embryonic development, edema of the pericardium, small head, axial deviation, delayed development of inner ear, closer location of two otoliths, delayed fusion of the semicircular canals, and abnormal otolith number in some cases. In addition, the behavior of zebrafish was also adversely affected with impaired balance and biased swimming route. Misexpression of miR-194 could strongly affected the development and differentiation of spiral ganglion neuron (SGN) in inner ear through Fgf4 in vitro. Similar results have also been observed that the overexpression and knockdown of miR-194 strongly disturbed the development and differentiation of the sensory patches and Statoacoustic ganglion (SAG) through Fgf4 in zebrafish in vivo. Our results indicated that miR-194 may regulate the development and differentiation of sensory patches and SAG through Fgf4. CONCLUSIONS Our data revealed a vital role of miR-194 in regulating the development and differentiation of the inner ear. PMID: 29570699 PMCID: PMC5880017


Signs of embryo-maternal communication: miRNAs in the maternal serum of pregnant pigs

Reproduction. 2017 Sep;154(3):117-128. doi: 10.1530/REP-17-0224. Epub 2017 Jun 7.

Reliszko ZP1, Gajewski Z2, Kaczmarek MM3,2,4.


Circulating miRNAs were proposed to be indicators of normal or complicated pregnancies. Based on this knowledge and our recent transcriptomic approach showing expression of miRNAs in the porcine endometrium, conceptuses and uterine extracellular vesicles during pregnancy, we have hypothesized that signs of ongoing local embryo-maternal crosstalk involving miRNAs can be detected in the circulation of pregnant gilts as early as a few days after maternal recognition of pregnancy. By applying several molecular biology techniques that differ in dynamic range and precision in maternal serum of Day 16 pregnant pigs, we were able to show for the first time increased levels of several miRNAs, previously reported to be expressed in either conceptuses and extracellular vesicles (miR-26a and miR-125b) or pregnant endometrium (miR-23b). Our results clearly showed that real-time RT-PCR and digital PCR are the most reliable methods, being able to detect small-fold changes of low-abundant circulating miRNAs. Further validation in a separate group of gilts confirmed an increase in miR-23b and miR-125b levels. In silico analyses identified pregnancy-related biological processes and pathways affected by these miRNAs. Target prediction analysis revealed hundreds of porcine transcripts with conserved sites for these miRNAs, which were classified into signaling pathways relevant to pregnancy. We conclude that a unique set of miRNAs can already be observed in the circulation of pigs during the first weeks of pregnancy, as a result of the initiation of embryo-maternal communication. © 2017 Society for Reproduction and Fertility.

PMID 28592665 DOI: 10.1530/REP-17-0224

Changes in circulating microRNA levels can be identified as early as day 8 of pregnancy in cattle

PLoS One. 2017 Apr 5;12(4):e0174892. doi: 10.1371/journal.pone.0174892. eCollection 2017.

Ioannidis J1, Donadeu FX1.


Poor reproductive performance remains a major issue in the dairy industry, with low conception rates having a significant impact on milk production through extended calving intervals. A major limiting factor is the lack of reliable methods for early pregnancy diagnosis. Identification of animals within a herd that fail to conceive within 3 weeks after insemination would allow early re-insemination and shorten calving intervals. In a previous study, we found an increase in plasma miR-26a levels in Day 16-pregnant relative to non-pregnant heifers, however changes in miRNA levels that early during pregnancy were very small which likely prevented the identification of robust biomarkers. In this study, we extended our analyses to a wider interval during pregnancy (Days 8 to 60, n = 11 heifers) with the rationale that this may facilitate the identification of additional early pregnancy miRNA biomarkers. Using small RNA sequencing we identified a total of 77 miRNAs that were differentially expressed on Day 60 relative to Day 0 of pregnancy. We selected 14 miRNAs for validation by RT-qPCR and confirmed significant differences in the expression of let-7f, let-7c, miR-30c, miR-101, miR-26a, miR-205 and miR-143 between Days 0 and 60. RT-qPCR profiling throughout Days 0, 8, 16 and 60 of pregnancy showed a distinct increase in circulating levels of miR-26a (3.1-fold, P = 0.046) as early as Day 8 of pregnancy. In summary, in contrast to earlier stages of pregnancy (≤ Day 24), marked differences in the levels of multiple miRNAs can be detected in circulation by Day 60 in cattle. Retrospective analyses showed miR-26a levels to be increased in circulation as early as Day 8, sooner than previously reported in any species, suggesting a biological role for this miRNA in the very early events of pregnancy. PMID: 28380001 PMCID: PMC5381804 DOI: 10.1371/journal.pone.0174892


Microarray analysis of microRNA deregulation and angiogenesis-related proteins in endometriosis

Genet Mol Res. 2016 Jun 3;15(2). doi: 10.4238/gmr.15027826.

Yang RQ1, Teng H1, Xu XH1, Liu SY2, Wang YH1, Guo FJ1, Liu XJ3.

1Department of Obstetrics and Gynecology, The Second Hospital of Jilin University, Changchun, Jilin Province, China. 2Department of Anesthesia, The Second Hospital of Jilin University, Changchun, Jilin Province, China. 3Department of Pathology, The First Hospital of Jilin University, Changchun, Jilin Province, China.


We examined the aberrant microRNA (miRNA) expression profile responsible for the changes in angiogenesis observed in endometriotic lesions. This study revealed characteristic miRNA expression profiles associated with endometriosis in endometrial tissue and endometriotic lesions from the same patient, and their correlation with the most important angiogenic and fibrinolytic factors. miRNA expression was quantified using a microRNA array and reverse-transcription microRNA polymerase chain reaction. Levels of vascular endothelial growth factor A (VEGFA), epidermal growth factor receptor 2 (EGFR2), phosphatase and tensin homolog (PTEN), and C-X-C chemokine receptor type 4 (CXCR4) were quantified using enzyme-linked immunosorbent assay. The endometrial tissue showed significantly lower levels of miR-200b, miR-15a-5p, miR-19b-1-5p, miR-146a-5p, and miR-200c, and higher levels of miR-16-5p, miR-106b-5p, and miR-145-5p. VEGFA was significantly upregulated, whereas EGFR2, PTEN, and CXCR4 were markedly downregulated, in the endometriotic tissues compared to that in the normal endometrial tissues. In conclusion, differences in the miRNA levels could modulate the expression of VEGFA, EGFR2, PTEN, and CXCR4, and may play an important role in the pathogenesis of endometriosis. The higher angiogenic and proteolytic activities observed in the eutopic endometrium might facilitate the implantation of endometrial cells at ectopic sites.

PMID 27323121

MicroRNAs modulating angiogenesis: miR-129-1 and miR-133 act as angio-miR in HUVECs

Tumour Biol. 2016 Jul;37(7):9527-34. doi: 10.1007/s13277-016-4845-0. Epub 2016 Jan 20.

Soufi-Zomorrod M1, Hajifathali A2, Kouhkan F3, Mehdizadeh M4, Rad SM3, Soleimani M5.


The sprouting of new blood vessels by angiogenesis is critical in vascular development and homeostasis. Aberrant angiogenesis leads to enormous pathological conditions such as ischemia and cancer. MicroRNAs (also known as miRNAs or miRs) play key roles in regulation of a range of cellular processes by posttranscriptional suppression of their target genes. Recently, new studies have indicated that miRNAs are involved in certain angiogenic settings and signaling pathways use these non-coding RNAs to promote or suppress angiogenic processes. Herein, VEGFR2 and FGFR1 were identified as miR-129-1 and miR-133 targets using bioinformatic algorithms, respectively. Afterwards, using luciferase reporter assay and gene expression analysis at both mRNA and protein levels, VEGFR2 and FGFR1 were validated as miR-129-1 and miR-133 targets. In addition, we showed that miR-129-1 and miR-133 suppress angiogenesis properties such as proliferation rate, cell viability, and migration activity of human umbilical vein endothelial cells (HUVEC) in vitro. We conclude that these miRNAs can suppress key factors of angiogenesis by directly targeting them. These results have important therapeutic implications for a variety of diseases involving deregulation of angiogenesis, including cancer. KEYWORDS: Angiogenesis; FGFR1; HUVEC cells; MiR-129-1; MiR-133; VEGFR2 PMID 26790441

MicroRNA Expression during Bovine Oocyte Maturation and Fertilization

Int J Mol Sci. 2016 Mar 18;17(3). pii: E396. doi: 10.3390/ijms17030396.

Gilchrist GC1, Tscherner A2, Nalpathamkalam T3, Merico D4, LaMarre J5.


Successful fertilization and subsequent embryo development rely on complex molecular processes starting with the development of oocyte competence through maturation. MicroRNAs (miRNAs) are small non-coding RNA molecules that function as gene regulators in many biological systems, including the oocyte and embryo. In order to further explore the roles of miRNAs in oocyte maturation, we employed small RNA sequencing as a screening tool to identify and characterize miRNA populations present in pools of bovine germinal vesicle (GV) oocytes, metaphase II (MII) oocytes, and presumptive zygotes (PZ). Each stage contained a defined miRNA population, some of which showed stable expression while others showed progressive changes between stages that were subsequently confirmed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Bta-miR-155, bta-miR-222, bta-miR-21, bta-let-7d, bta-let-7i, and bta-miR-190a were among the statistically significant differentially expressed miRNAs (p < 0.05). To determine whether changes in specific primary miRNA (pri-miRNA) transcripts were responsible for the observed miRNA changes, we evaluated pri-miR-155, -222 and let-7d expression. Pri-miR-155 and -222 were not detected in GV oocytes but pri-miR-155 was present in MII oocytes, indicating transcription during maturation. In contrast, levels of pri-let-7d decreased during maturation, suggesting that the observed increase in let-7d expression was likely due to processing of the primary transcript. This study demonstrates that both dynamic and stable populations of miRNAs are present in bovine oocytes and zygotes and extend previous studies supporting the importance of the small RNA landscape in the maturing bovine oocyte and early embryo. KEYWORDS: in vitro fertilization (IVF); in vitro maturation (IVM); miR-155; miRNA; next-generation sequencing

PMID 26999121

MicroRNA Profiles in Spontaneous Decidualized Menstrual Endometrium and Early Pregnancy Decidua with Successfully Implanted Embryos

PLoS One. 2016 Jan 6;11(1):e0143116. doi: 10.1371/journal.pone.0143116. eCollection 2016.

Wang Y1,2, Lv Y1, Gao S3, Zhang Y3, Sun J1, Gong C1, Chen X2, Li G1.


To comparatively analyze the human microRNA (miRNA) profiles between spontaneous decidualized menstrual endometrium and early pregnancy decidua by an in-depth sequencing of miRNAs. The specific miRNAs expressed at conception might be involved in pregnancy establishment and expression of let-7f-5p and let-7g-5p was experimentally up-regulated or inhibited to assess the effect on the expression of IGF2BP-1 and IGF2R in vitro, respectively. Samples of endometria and deciduas were obtained from 25 women who suffered from tubal or male factor subfertility and from 35 early pregnant women who underwent pregnancy termination at 6-8 weeks gestation were irrespectively collected and comparatively analyzed by miRNA sequencing and differential expression of known and novel miRNAs was analyzed using bioinformatics. The 2042 miRNA expression was analyzed in the study and the differential expression of six miRNAs was validated by qRT-PCR. The expression of four miRNAs in decidua samples was down-regulated (miR-34c, miR-92a, miR-181a-5p, and miR-191), whereas the expression of miR-10a-5p and let-7f-5p was significantly up-regulated. The expression of IGF2BP-1 and IGF2R declined and increased with overexpression and inhibition of let-7f-5p and let-7g-5p, respectively. Changes in the expression of particular miRNAs might play a role in the physiology of decidualization following successful embryo implantation, ultimately resulting in continuous decidualization.

PMID 26735129


MiR-204 is responsible for inherited retinal dystrophy associated with ocular coloboma

Proc Natl Acad Sci U S A. 2015 Jun 8. pii: 201401464. [Epub ahead of print]

Conte I1, Hadfield KD2, Barbato S1, Carrella S1, Pizzo M1, Bhat RS1, Carissimo A1, Karali M1, Porter LF3, Urquhart J3, Hateley S2, O'Sullivan J2, Manson FD2, Neuhauss SC4, Banfi S5, Black GC6.


Ocular developmental disorders, including the group classified as microphthalmia, anophthalmia, and coloboma (MAC) and inherited retinal dystrophies, collectively represent leading causes of hereditary blindness. Characterized by extreme genetic and clinical heterogeneity, the separate groups share many common genetic causes, in particular relating to pathways controlling retinal and retinal pigment epithelial maintenance. To understand these shared pathways and delineate the overlap between these groups, we investigated the genetic cause of an autosomal dominantly inherited condition of retinal dystrophy and bilateral coloboma, present in varying degrees in a large, five-generation family. By linkage analysis and exome sequencing, we identified a previously undescribed heterozygous mutation, n.37C > T, in the seed region of microRNA-204 (miR-204), which segregates with the disease in all affected individuals. We demonstrated that this mutation determines significant alterations of miR-204 targeting capabilities via in vitro assays, including transcriptome analysis. In vivo injection, in medaka fish (Oryzias latipes), of the mutated miR-204 caused a phenotype consistent with that observed in the family, including photoreceptor alterations with reduced numbers of both cones and rods as a result of increased apoptosis, thereby confirming the pathogenic effect of the n.37C > T mutation. Finally, knockdown assays in medaka fish demonstrated that miR-204 is necessary for normal photoreceptor function. Overall, these data highlight the importance of miR-204 in the regulation of ocular development and maintenance and provide the first evidence, to our knowledge, of its contribution to eye disease, likely through a gain-of-function mechanism. KEYWORDS: coloboma; miR-204; microRNA; retinal degeneration; retinitis pigmentosa PMID 26056285

Maternal peripheral blood natural killer cells incorporate placenta-associated microRNAs during pregnancy

Int J Mol Med. 2015 Jun;35(6):1511-24. doi: 10.3892/ijmm.2015.2157. Epub 2015 Mar 27.

Ishida Y1, Zhao D2, Ohkuchi A1, Kuwata T1, Yoshitake H2, Yuge K2, Takizawa T2, Matsubara S1, Suzuki M1, Saito S3, Takizawa T2.


Although recent studies have demonstrated that microRNAs (miRNAs or miRs) regulate fundamental natural killer (NK) cellular processes, including cytotoxicity and cytokine production, little is known about the miRNA‑gene regulatory relationships in maternal peripheral blood NK (pNK) cells during pregnancy. In the present study, to determine the roles of miRNAs within gene regulatory networks of maternal pNK cells, we performed comprehensive miRNA and gene expression profiling of maternal pNK cells using a combination of reverse transcription quantitative PCR (RT‑qPCR)‑based miRNA array and DNA microarray analyses and analyzed the differential expression levels between first‑ and third‑trimester pNK cells. Furthermore, we constructed regulatory networks for miRNA‑mediated gene expression in pNK cells during pregnancy by Ingenuity Pathway Analysis (IPA). PCR‑based array analysis revealed that the placenta‑derived miRNAs [chromosome 19 miRNA cluster (C19MC) miRNAs] were detected in pNK cells during pregnancy. Twenty‑five miRNAs, including six C19MC miRNAs, were significantly upregulated in the third‑ compared to first‑trimester pNK cells. The rapid clearance of C19MC miRNAs also occurred in the pNK cells following delivery. Nine miRNAs, including eight C19MC miRNAs, were significantly downregulated in the post‑delivery pNK cells compared to those of the third‑trimester. DNA microarray analysis identified 69 NK cell function‑related genes that were differentially expressed between the first‑ and third‑trimester pNK cells. On pathway and network analysis, the observed gene expression changes of pNK cells likely contribute to the increase in the cytotoxicity, as well as the cell cycle progression of third‑ compared to first‑trimester pNK cells. Thirteen of the 69 NK cell function‑related genes were significantly downregulated between the first‑ and third‑trimester pNK cells. Nine of the 13 downregulated NK‑function‑associated genes were in silico target candidates of 12 upregulated miRNAs, including C19MC miRNA miR‑512‑3p. The results of this study suggest that the transfer of placental C19MC miRNAs into maternal pNK cells occurs during pregnancy. The present study provides new insight into maternal NK cell functions.

PMID 25824636


The Lin28/Let-7 System in Early Human Embryonic Tissue and Ectopic Pregnancy

PLoS ONE 9(1): e87698. doi:10.1371/journal.pone.0087698

Lozoya T, Domınguez F, Romero-Ruiz A, Steffani L, Martınez S, et al. (2014)


Our objective was to determine the expression of the elements of the Lin28/Let-7 system, and related microRNAs (miRNAs), in early stages of human placentation and ectopic pregnancy, as a means to assess the potential role of this molecular hub in the pathogenesis of ectopic gestation. Seventeen patients suffering from tubal ectopic pregnancy (cases) and forty-three women with normal on-going gestation that desired voluntary termination of pregnancy (VTOP; controls) were recruited for the study. Embryonic tissues were subjected to RNA extraction and quantitative PCR analyses for LIN28B, Let-7a, miR-132, miR-145 and mir-323-3p were performed. Our results demonstrate that the expression of LIN28B mRNA was barely detectable in embryonic tissue from early stages of gestation and sharply increased thereafter to plateau between gestational weeks 7–9. In contrast, expression levels of Let-7, mir-132 and mir-145 were high in embryonic tissue from early gestations (#6-weeks) and abruptly declined thereafter, especially for Let-7. Opposite trends were detected for mir-323-3p. Embryonic expression of LIN28B mRNA was higher in early stages (#6-weeks) of ectopic pregnancy than in normal gestation. In contrast, Let-7a expression was significantly lower in early ectopic pregnancies, while miR-132 and miR-145 levels were not altered. Expression of mir-323-3p was also suppressed in ectopic embryonic tissue. We are the first to document reciprocal changes in the expression profiles of the gene encoding the RNA-binding protein, LIN28B, and the related miRNAs, Let-7a, mir-132 and mir-145, in early stages of human placentation. This finding suggests the potential involvement of LIN28B/Let-7 (de)regulated pathways in the pathophysiology of ectopic pregnancy in humans.

  • LIN28B barely detectable in embryonic tissue from early stages of gestation and sharply increased thereafter to plateau between gestational weeks 7–9. higher in early stages of ectopic pregnancy than in normal gestation.
  • Let-7, mir-132 and mir-145 were high in embryonic tissue from early gestations (less/to 6-weeks) the declined especially for Let-7.
  • mir-323-3p - opposite trend detected.


  • LIN28B higher in early stages than in normal gestation.
  • Let-7a expression significantly lower in early ectopic pregnancies
  • miR-132 and miR-145 levels were not altered.
  • mir-323-3p was also suppressed in ectopic embryonic tissue.

PMID 24498170

Potential Regulatory Role of MicroRNAs in the Development of Bovine Gastrointestinal Tract during Early Life

PLoS One. 2014 Mar 28;9(3):e92592. doi: 10.1371/journal.pone.0092592. eCollection 2014.

Liang G1, Malmuthuge N1, McFadden TB2, Bao H1, Griebel PJ3, Stothard P1, Guan LL1. Author information

Abstract This study aimed to investigate the potential regulatory role of miRNAs in the development of gastrointestinal tract (GIT) during the early life of dairy calves. Rumen and small intestinal (mid-jejunum and ileum) tissue samples were collected from newborn (30 min after birth; n = 3), 7-day-old (n = 6), 21-day-old (n = 6), and 42-day-old (n = 6) dairy calves. The miRNA profiling was performed using Illumina RNA-sequencing and the temporal and regional differentially expressed miRNAs were further validated using qRT-PCR. Analysis of 16S rRNA gene copy numbers was used to quantify total bacteria, Bifidobacterium and Lactobacillus species. The expression of miR-143 was abundant in all three gut regions, at all time points and it targets genes involved primarily in the proliferation of connective tissue cells and muscle cells, suggesting a role in regulating rapid tissue development during the early life of calves. The expression of miR-146, miR-191, miR-33, miR-7, miR-99/100, miR-486, miR-145, miR-196 and miR-211 displayed significant temporal differences (FDR <0.05), while miR-192/215, miR-194, miR-196, miR-205 and miR-31 revealed significant regional differences (FDR <0.05). The expression levels of miR-15/16, miR-29 and miR-196 were positively correlated with the copy numbers of 16S rRNA gene of Bifidobacterium or Lactobacillus species or both (P<0.05). Functional analysis using Ingenuity Pathway Analysis identified the above mentioned differentially expressed miRNAs as potential regulators of gut tissue cell proliferation and differentiation. The bacterial density-associated miRNAs were identified as modulators of the development of lymphoid tissues (miR-196), maturation of dendritic cells (miR-29) and development of immune cells (miR-15/16). The present study revealed temporal and regional changes in miRNA expression and a correlation between miRNA expression and microbial population in the GIT during the early life, which provides further evidence for another mechanism by which host-microbial interactions play a role in regulating gut development.

PMID 24682221


miR-196b targets c-myc and Bcl-2 expression, inhibits proliferation and induces apoptosis in endometriotic stromal cells

Hum Reprod. 2013 Mar;28(3):750-61. doi: 10.1093/humrep/des446. Epub 2013 Jan 4.

Abe W1, Nasu K, Nakada C, Kawano Y, Moriyama M, Narahara H.


STUDY QUESTION: What is the global expression pattern of microRNAs (miRNAs) in endometriotic stromal cells and is miR-196b involved in the pathogenesis of endometriosis? SUMMARY ANSWER: Several miRNAs are aberrantly expressed in endometriotic cyst stromal cells (ECSCs), including miR-196b whose expression is repressed in endometriotic stromal cells. WHAT IS KNOWN ALREADY: Although, histologically, endometriotic tissues and normal proliferative endometrium are similar, a number of distinct molecular differences have been reported to date. The anti-apoptotic and excessive proliferative properties of endometriotic cells are considered to be involved in the development and progression of endometriosis. STUDY DESIGN AND SIZE DURATION: ECSCs and normal endometrial stromal cells (NESCs) were isolated from ovarian endometriotic tissues and eutopic endometrial tissues, respectively and compared. PARTICIPANTS/MATERIALS, SETTING AND METHODS: Aberrantly expressed miRNAs in ECSCs were identified by a global miRNA microarray technique. The roles of miR-196b in ECSC proliferation, apoptosis, and c-myc and B-cell lymphoma/leukemia (Bcl)-2 mRNA expression were investigated with precursor hsa-miR-196b transfection. The methylation status of the miR-196b gene in ECSCs and the effect of a DNA demethylating agent on miR-196b expression were also examined. MAIN RESULTS AND THE ROLE OF CHANCE: miRNA microarray analysis identified eight down-regulated miRNAs (including miR-196b) and four up-regulated miRNAs in ECSCs. Compulsory expression of miR-196b directed the inhibition of proliferation and the induction of apoptosis in ECSCs. miR-196b was found to suppress c-myc and Bcl-2 mRNA expression in ECSCs, and there was a significant correlation between miR-196b and HOXA10 expression in ECSCs and NESCs. The miR-196b gene was hypermethylated in ECSCs when compared with NESCs, and the treatment with a DNA demethylating agent restored the expression of miR-196b in ECSCs. LIMITATIONS AND REASONS FOR CAUTION: miRNA expression profiles were investigated only in the stromal component of ectopic and eutopic endometrium samples. In addition to miR-196b, the roles of other miRNAs aberrantly expressed in ECSCs should be examined. WIDER IMPLICATIONS OF THE FINDINGS: The present findings suggest that aberrant miRNA expression plays an important role in the pathogenesis of endometriosis as a part of epigenetic mechanisms, that expression of miR-196b in ECSCs is repressed by DNA hypermethylation of the miR-196b gene and this repression may be involved in the development of proliferative and anti-apoptotic characteristics of endometriosis. STUDY FUNDING: This work was supported in part by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (no. 20591920 to K.N. and no. 23592407 to H.N.) and The Uehara Memorial Foundation (to K.N.).

PMID 23293219

miRNA regulated pathways in late stage murine lung development

BMC Dev Biol. 2013 Apr 24;13:13. doi: 10.1186/1471-213X-13-13.

Mujahid S1, Logvinenko T, Volpe MV, Nielsen HC. Author information

Abstract BACKGROUND: MicroRNAs play important roles in regulating biological processes, including organ morphogenesis and maturation. However, little is known about specific pathways regulated by miRNA during lung development. Between the canalicular and saccular stages of the developing lung several important cellular events occur, including the onset of surfactant synthesis, microvascular remodeling and structural preparation for subsequent alveolarization. The miRNAs that are actively regulated, and the identity of their targets during this important developmental interval in the lung remain elusive. RESULTS: Using TLDA low density real-time PCR arrays, the expression of 376 miRNAs in male and female fetal mouse lungs of gestational days E15 - E18 were profiled. Statistical analyses identified 25 and 37 miRNAs that changed significantly between sexes and with gestation, respectively. In silico analysis using Ingenuity Pathway Analysis (IPA) identified specific pathways and networks known to be targets of these miRNAs which are important to lung development. Pathways that are targeted by sex regulated miRNAs include retinoin, IGFR1, Tp53 and Akt. Pathways targeted by gestation-regulated miRNAs include VEGFA and mediators of glucose metabolism. CONCLUSION: MiRNAs are differentially regulated across time and between sexes during the canalicular and saccular stages of lung development. Sex-associated differential miRNA expression may regulate the differences in structural and functional male and female lung development, as shown by networks generated using in silico analysis. These data provide a valuable resource to further enhance the understanding of miRNA control of lung development and maturation. PMID 23617334


A survey of small RNAs in human sperm

Hum Reprod. 2011 Dec;26(12):3401-12. Epub 2011 Oct 11. Krawetz SA, Kruger A, Lalancette C, Tagett R, Anton E, Draghici S, Diamond MP. Source Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA. Abstract BACKGROUND There has been substantial interest in assessing whether RNAs (mRNAs and sncRNAs, i.e. small non-coding) delivered from mammalian spermatozoa play a functional role in early embryo development. While the cadre of spermatozoal mRNAs has been characterized, comparatively little is known about the distribution or function of the estimated 24 000 sncRNAs within each normal human spermatozoon. METHODS RNAs of <200 bases in length were isolated from the ejaculates from three donors of proved fertility. RNAs of 18-30 nucleotides in length were then used to construct small RNA Digital Gene Expression libraries for Next Generation Sequencing. Known sncRNAs that uniquely mapped to a single location in the human genome were identified. RESULTS Bioinformatic analysis revealed the presence of multiple classes of small RNAs in human spermatozoa. The primary classes resolved included microRNA (miRNAs) (≈7%), Piwi-interacting piRNAs (≈17%), repeat-associated small RNAs (≈65%). A minor subset of short RNAs within the transcription start site/promoter fraction (≈11%) frames the histone promoter-associated regions enriched in genes of early embryonic development. These have been termed quiescent RNAs. CONCLUSIONS A complex population of male derived sncRNAs that are available for delivery upon fertilization was revealed. Sperm miRNA-targeted enrichment in the human oocyte is consistent with their role as modifiers of early post-fertilization. The relative abundance of piRNAs and repeat-associated RNAs suggests that they may assume a role in confrontation and consolidation. This may ensure the compatibility of the genomes at fertilization.

PMID 21989093


MicroRNA networks in mouse lung organogenesis

PLoS One. 2010 May 26;5(5):e10854. doi: 10.1371/journal.pone.0010854.

Dong J1, Jiang G, Asmann YW, Tomaszek S, Jen J, Kislinger T, Wigle DA. Author information

Abstract BACKGROUND: MicroRNAs (miRNAs) are known to be important regulators of both organ development and tumorigenesis. MiRNA networks and their regulation of messenger RNA (mRNA) translation and protein expression in specific biological processes are poorly understood. METHODS: We explored the dynamic regulation of miRNAs in mouse lung organogenesis. Comprehensive miRNA and mRNA profiling was performed encompassing all recognized stages of lung development beginning at embryonic day 12 and continuing to adulthood. We analyzed the expression patterns of dynamically regulated miRNAs and mRNAs using a number of statistical and computational approaches, and in an integrated manner with protein levels from an existing mass-spectrometry derived protein database for lung development. RESULTS: In total, 117 statistically significant miRNAs were dynamically regulated during mouse lung organogenesis and clustered into distinct temporal expression patterns. 11,220 mRNA probes were also shown to be dynamically regulated and clustered into distinct temporal expression patterns, with 3 major patterns accounting for 75% of all probes. 3,067 direct miRNA-mRNA correlation pairs were identified involving 37 miRNAs. Two defined correlation patterns were observed upon integration with protein data: 1) increased levels of specific miRNAs directly correlating with downregulation of predicted mRNA targets; and 2) increased levels of specific miRNAs directly correlating with downregulation of translated target proteins without detectable changes in mRNA levels. Of 1345 proteins analyzed, 55% appeared to be regulated in this manner with a direct correlation between miRNA and protein level, but without detectable change in mRNA levels. CONCLUSION: Systematic analysis of microRNA, mRNA, and protein levels over the time course of lung organogenesis demonstrates dynamic regulation and reveals 2 distinct patterns of miRNA-mRNA interaction. The translation of target proteins affected by miRNAs independent of changes in mRNA level appears to be a prominent mechanism of developmental regulation in lung organogenesis.

PMID 20520778

Small RNAs in the animal gonad: guarding genomes and guiding development

Int J Biochem Cell Biol. 2010 Aug;42(8):1334-47. Epub 2010 Mar 19.

Lau NC. Source Department of Biology, Brandeis University, 415 South Street, Waltham, MA 02454, USA.


Germ cells must safeguard, apportion, package, and deliver their genomes with exquisite precision to ensure proper reproduction and embryonic development. Classical genetic approaches have identified many genes controlling animal germ cell development, but only recently have some of these genes been linked to the RNA interference (RNAi) pathway, a gene silencing mechanism centered on small regulatory RNAs. Germ cells contain microRNAs (miRNAs), endogenous siRNAs (endo-siRNAs), and Piwi-interacting RNAs (piRNAs); these are bound by members of the Piwi/Argonaute protein family. piwi genes were known to specify germ cell development, but we now understand that mutations disrupting germline development can also affect small RNA accumulation. Small RNA studies in germ cells have revealed a surprising diversity of regulatory mechanisms and a unifying function for germline genes in controlling the spread of transposable elements. Future challenges will be to understand the production of germline small RNAs and to identify the full breadth of gene regulation by these RNAs. Progress in this area will likely impact biomedical goals of manipulating stem cells and preventing diseases caused by the transposition of mobile DNA elements.

Copyright 2010 Elsevier Ltd. All rights reserved.

PMID 20227517