Circ-8073 regulates CEP55 by sponging miR-449a to promote caprine endometrial epithelial cells proliferation via the PI3K/AKT/mTOR pathway

Identification and expression profile analysis of circRNAs associated with goat uterus with different fecundity during estrous cycle

BACKGROUND

The Yunshang Black Goat, a distinguished meat goat breed native to China, is renowned for its superior reproductive capabilities. Despite this, there is considerable phenotypic variability within the breed. During the reproductive cycle, the uterus plays a pivotal role, with its functions evolving in line with the different stages of the cycle. This study focuses on the uterine tissues, including both the endometrium and myometrium, of Yunshang Black Goats with high fecundity (HF) and low fecundity (LF) during the proliferative (FP) and secretory (LP) phases of the estrous cycle. By examining these tissues, we aim to elucidate the underlying molecular and physiological mechanisms of the observed differences in reproductive success.

RESULTS

High-throughput sequencing was conducted, followed by bioinformatics analysis to identify the expression profiles of circRNAs. A total of 7,445 circRNAs were identified through the integration of findings from find_circ and CIRI2 software. Comparative analyses between the FPLF vs. FPHF and LPLF vs. LPHF revealed 149 differentially expressed (DE) circRNAs (94 up-regulated and 55 down-regulated) and 276 DE circRNAs (56 up-regulated and 220 down-regulated), respectively. The enrichment analysis indicated that the primary pathways involved were the Sphingolipid signaling pathway, MAPK signaling pathway, and GnRH signaling pathway, all of which are closely associated with cellular growth and development. Additionally, several key candidate genes were identified, such as FGF2 and MBTPS1. We also predicted a total of 281 miRNA-circRNA binding pairs, encompassing 263 circRNAs and 60 miRNAs, and simultaneously, 14 coding circRNAs were anticipated.

CONCLUSION

Based on the analysis, we have established the expression profiles of circRNAs during the follicular and luteal phases, respectively. Furthermore, using various analytical methods and data from high- and low-yield experimental control groups over different periods, we have identified multiple circRNAs that affect the high reproductive capacity of goats. Through enrichment analysis of the host genes of these circRNAs, we have discovered several key candidate genes. These findings provide fundamental data for the study of the molecular mechanisms underlying the fecundity of goats and pave the way for future genetic improvement strategies.

WD-repeat containing protein-61 regulates endometrial epithelial cell adhesion indicating an important role in receptivity

Endometrial receptivity is crucial for successful embryo implantation during early pregnancy. The human endometrium undergoes remodeling within each menstrual cycle to prepare or become receptive to an implanting blastocyst in the mid-secretory phase. However, the mechanisms behind these changes are not fully understood. Recently, using hormone-treated endometrial organoids to model receptivity, we identified that the transcriptional regulator WD-repeat-containing protein-61 (WDR61) was reduced in organoids derived from infertile women. In this study, we aimed to determine the role of WDR61 in endometrial receptivity. Here, we demonstrated that WDR61 immunolocalizes in the nuclei and cytosol of endometrial glandular epithelium, luminal epithelium, and stroma. The staining intensity of WDR61 was significantly higher during the receptive mid-secretory phase compared to the non-receptive proliferative phase in fertile women. In a functional experiment to model blastocyst adhesion to the endometrial epithelium, we found that adhesion of cytotrophoblast progenitor spheroids was blocked when siRNA was used to knockdown WDR61 in primary endometrial epithelial cells. Similarly, in Ishikawa cells (a receptive human endometrial epithelial cell line), siRNA knockdown of WDR61 significantly reduced the cell adhesive and proliferative capacities. qPCR revealed that WDR61 knockdown reduced expression of key genes involved in receptivity including HOXD10, MMP2, and CD44. Chromatin immunoprecipitation sequencing demonstrated that WDR61 directly targeted 2022 genes in Ishikawa cells, with functions including focal adhesion, intracellular signaling and epithelial-mesenchymal transition. Overall, these findings suggest that WDR61 promotes endometrial receptivity by modulating epithelial cell focal adhesions, proliferation, and epithelial-mesenchymal transition.

The Effect of Selenium on Endometrial Repair in Goats with Endometritis at High Cortisol Levels

Endometritis is a common postpartum disease of female animals that causes significant losses to the goat industry. High levels of cortisol induced by various stresses after delivery severely inhibit innate immunity and tissue repair. The repair ability of the endometrium is closely related to the reproductive performance of goats. Selenium (Se) is an essential trace element in animals that has powerful antioxidant and immunity-enhancing functions. In this study, we established a goat model of endometritis at high cortisol (Hydrocortisone) levels to investigate the effect of Se (supplement additive) on endometrial repair. The results showed that the clinical symptoms, %PMN in uterine secretions, morphological endometrial damage, and the gene expression of BAX were reduced in the goats with Se supplementation compared with those in the model group. Se increased the gene expression of BCL2, VEGFA, TGFB1, and PCNA and activated the PI3K/AKT and Wnt/β-catenin signaling pathways in goats with Se supplementation. In conclusion, Se reduced the inflammatory response, increased the proliferation, and decreased the apoptosis of endometrial cells to promote endometrial tissue repair in goats with endometritis at high cortisol levels. It probably achieved this effect of promoting repair by activating the Wnt/β-catenin and PI3K/AKT pathways and affecting the gene expression of VEGFA, TGFB1, PCNA, BCL2, and BAX.

The identification and functional analysis of CircRNAs in endometrial receptivity of mice with polycystic ovary

The disorders of endometrial receptivity and ovulatory dysfunction are both significant causes of infertility in patients with polycystic ovary syndrome (PCOS). In this study, we investigated the expression profile and functional implications of circular RNAs (circRNAs) in the endometrial receptivity of PCOS-affected mice. Twenty-four female C57BL/6 mice were divided into PCOS and normal control groups. The PCOS group received subcutaneous DHEA treatment, while the control group remained untreated. Gene chip technology was utilized to analyze circRNA expression in endometrial tissues on the fourth day of gestation with subsequent bioinformatics analyses into circRNA functions. Furthermore, endometrial epithelial cells were used to determine represented circRNA functions. Results showed that the PCOS group exhibited 205 differentially expressed circRNAs, with 147 upregulated and 58 downregulated ones. qRT-PCR confirmed differential expression of circRNAs, including circRNA_38548, circRNA_001686, circRNA_38550, and circRNA_27938. Predicted target genes and a circRNA-miRNA-mRNA regulatory network were constructed. Additionally, four circRNAs (circRNA_38548, circRNA_38550, and circRNA_001686) were identified to contribute to abnormal endometrial receptivity by regulating genes such as Lifr, FOXK1, FOXO1, HOXA10, through interactions with miRNAs. Further research is warranted to elucidate the underlying mechanisms involving these circRNAs.

LIF regulates the expression of miR-27a-3p and HOXA10 in bovine endometrial epithelial cells via STAT3 pathway

LIF is crucial in regulating embryo implantation, while HOXA10 is a marker gene for uterine receptivity. However, the specific mechanism of LIF regulating HOXA10 during cow embryo implantation has not been fully understood. To address this knowledge gap, the experiment involved treating bovine endometrial epithelial cells (BEECs) with LIF to investigate the relationship between LIF, miRNA, and HOXA10. The experimental findings revealed that applying LIF resulted in a substantial increase in the proliferation of endometrial epithelial cells. Moreover, the expressions of PI3K, AKT, HOXA10, CDK4, cyclinD1, and cyclinE1 were significantly elevated. Conversely, the expression of p21Cipl was significantly reduced. In the group that received a combination of LIF and a STAT3 inhibitor, the expression of PI3K/AKT remained significantly increased, but there was no significant change in the expression of HOXA10. When miRNA-27a-3p was overexpressed, it resulted in a decrease in both the RNA and protein expression of HOXA10. Conversely, inhibiting miRNA-27a-3p increased the RNA and protein expression of HOXA10. In the presence of LIF treatment, the expression of miRNA-27a-3p was reduced, while the expression of HOXA10 was increased. However, when LIF and a STAT3 inhibitor were combined, there was no significant change in the expression of miRNA-27a-3p or HOXA10. Consequently, LIF facilitated cell proliferation by activating the PI3K/AKT pathway. LIF controlled the expression of miRNA-27a-3p and HOXA10 in endometrial epithelial cells through STAT3, with miRNA-27a-3p negatively regulating the expression of HOXA10.

Parthenolide repressed endometriosis induced surgically in rats: Role of PTEN/PI3Kinase/AKT/GSK-3β/β-catenin signaling in inhibition of epithelial mesenchymal transition

AIM

PI3K/AKT/GSK-3β/β-catenin signaling pathway is a triggering factor for epithelial to mesenchymal transition (EMT) which plays a pivotal role in the pathogenesis of endometriosis. Parthenolide is a sesquiterpene lactone extract that has anti-inflammatory, analgesic and anticancer properties. Hence, we investigated the effect of parthenolide against EMT in the endometrial tissue implants and immortalized epithelial endometriotic cell lines 12Z.

MAIN METHODS

Twenty- four female Rats with surgically induced endometriosis were treated with parthenolide (2, 4 mg/kg), for 4 weeks. Endometriotic cell line 12Z was used to identify the effect of parthenolide on the wound healing, cellular migration and invasion properties of endometriotic cells.

KEY FINDINGS

Parthenolide decreased the endometriotic implant tissue expression of total PI3K, PI3K-p85, p-AKT, p/total AKT, p-GSK-3β, P/total GSK-3β, and nβ-catenin, as well as increased E-cadherin and decreased vimentin mRNA expression. Parthenolide upregulated PTEN immunoreactivity as well as the endometriotic tissue caspase-3, caspase-9, BAX levels while reducing Bcl2 level. Additionally, parthenolide decreased endometriotic tissue implants surface area and histopathological score of the epithelial growth.

SIGNIFICANCE

Our findings showed that parthenolide in a dose dependent manner inhibited PI3K/AKT/GSK-3β/nβ-catenin cascade via enhancement of PTEN with subsequent inhibition of EMT evidenced by elevation of the epithelial marker, E-cadherin and reduction of mesenchymal marker, vimentin, of the endometriotic implants in addition to reversal of invasion and migration properties of epithelial endometriotic cell lines. These findings provide a valuable therapeutic approach for treatment of endometriosis.

Identification and characterization of circRNAs in peri-implantation endometrium between Yorkshire and Erhualian pigs

BACKGROUND

One of the most critical periods for the loss of pig embryos is the 12th day of gestation when implantation begins. Recent studies have shown that non-coding RNAs (ncRNAs) play important regulatory roles during pregnancy. Circular RNAs (circRNAs) are a kind of ubiquitously expressed ncRNAs that can directly regulate the binding proteins or regulate the expression of target genes by adsorbing micro RNAs (miRNA).

RESULTS

We used the Illumina Novaseq6,000 technology to analyze the circRNA expression profile in the endometrium of three Erhualian (EH12) and three Yorkshire (YK12) pigs on day 12 of gestation. Overall, a total of 22,108 circRNAs were identified. Of these, 4051 circRNAs were specific to EH12 and 5889 circRNAs were specific to YK12, indicating a high level of breed specificity. Further analysis showed that there were 641 significant differentially expressed circRNAs (SDEcircRNAs) in EH12 compared with YK12 (FDR < 0.05). Functional enrichment of differential circRNA host genes revealed many pathways and genes associated with reproduction and regulation of embryo development. Network analysis of circRNA-miRNA interactions further supported the idea that circRNAs act as sponges for miRNAs to regulate gene expression. The prediction of differential circRNA binding proteins further explored the potential regulatory pathways of circRNAs. Analysis of SDEcircRNAs suggested a possible reason for the difference in embryo survival between the two breeds at the peri-implantation stage.

CONCLUSIONS

Together, these data suggest that circRNAs are abundantly expressed in the endometrium during the peri-implantation period in pigs and are important regulators of related genes. The results of this study will help to further understand the differences in molecular pathways between the two breeds during the critical implantation period of pregnancy, and will help to provide insight into the molecular mechanisms that contribute to the establishment of pregnancy and embryo loss in pigs.

Characterization of circular RNA profiles of oviduct reveal the potential mechanism in prolificacy trait of goat in the estrus cycle

The mammalian oviduct is functionally highly diverse during the estrus cycle. It provides a suitable milieu for oocyte maturation, sperm capacitation, fertilization, early embryo development and transportation. While there have been many studies of molecular mechanisms on the kidding number of goats, a systematic analysis by which the underlying circular RNAs (circRNAs) changes in the oviduct related to prolificacy traits is lacking. Herein, we present a comprehensive circRNA atlas of the oviduct among high- and low-fecundity goats in the follicular phase (FH vs. FL), luteal phase (LH vs. LL), and estrus cycle (FH vs. LH; FL vs. LL) to unravel their potential regulatory mechanisms in improving kidding number. We generated RNA sequencing data, and identified 4,078 circRNAs from twenty sampled Yunshang black goats. Many of these circRNAs are exon-derived and differentially expressed between each comparison group. Subsequently, eight differentially expressed (DE) circRNAs were validated by RT‒qPCR, which was consistent with the RNA-seq data. GO and KEGG enrichment analyses suggested that numerous host genes of DE circRNAs were involved in the hormone secretion, gamete production, fertilization, and embryo development processes. The competing endogenous RNA (ceRNA) interaction network analysis revealed that 2,673 circRNA–miRNA–mRNA axes (including 15 DE circRNAs, 14 miRNAs, and 1,699 mRNAs) were formed, and several target genes derived from the ceRNA network were associated with oviduct functions and reproduction, including SMAD1, BMPR1B, IGF1, REV1, and BMP2K. Furthermore, miR-15a-5p, miR-181b-5p, miR-23b-5p, miR-204-3p, and miR-145-5p might play important roles in reproduction. Finally, a novel circRNA, circIQCG, was identified as potentially involved in embryo development. Overall, our study provides a resource of circRNAs to understand the oviductal function and its connection to prolificacy trait of goats in the differentiation estrus cycle.

The Expression and Bioinformatics Analysis of Circular RNAs in Endometritis Mouse Uterus Tissues

Previous studies have shown that circular RNAs are directly or indirectly involved in the occurrence of various diseases by regulating gene expression. However, the acting mechanism of circular RNAs in endometritis remains unclear. In this study, we successfully established an endometritis model in mouse using Escherichia coli; endometrial integrity was destroyed, inflammatory cells infiltrated and the expression of IL-6, IL-1β, TNF-α was significantly up-regulated. We analyzed and screened the circular RNA expression profiles between healthy and endometritis-stricken mice by the Illumina HiSeq platform, and used qRT-PCR method to verify the different expressions of circular RNAs. Gene ontology (GO) analysis showed that circular RNAs were mainly involved in biological processes such as the positive regulation of transcription from RNA polymerase POL II promoter and the negative regulation of cell proliferation. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of circular RNAs target genes may be involved in the TGF-β signaling pathway. We verified the expression of TGF-β and its related factors; the mRNA of TGF-β1 and smad7 were significantly up-regulated in endometritis mouse (p < 0.01) and the protein expression level of p-smad3 was significantly decreased (p < 0.01). Finally, we constructed a circular RNAs−miRNA network to elucidate the potential regulatory relationship between two small molecules. This research may provide new ideas for circular RNAs in the treatment of endometritis.

Expression Profile Analysis to Identify Circular RNA Expression Signatures in Muscle Development of Wu'an Goat Longissimus Dorsi Tissues

The growth and development of skeletal muscle is a physiological process regulated by a variety of genes and signaling pathways. As a posttranscriptional regulatory factor, circRNA plays a certain regulatory role in the development of animal skeletal muscle in the form of a miRNA sponge. However, the role of circRNAs in muscle development and growth in goats is still unclear. In our study, apparent differences in muscle fibers in Wu'an goats of different ages was firstly detected by hematoxylin-eosin (HE) staining, the circRNA expression profiles of longissimus dorsi muscles from 1-month-old (mon1) and 9-month-old (mon9) goats were screened by RNA-seq and verified by RT-qPCR. The host genes of differentially expressed (DE) circRNAs were predicted, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses (KEGG) of host genes with DE circRNAs were performed to explore the functions of circRNAs. The circRNA-miRNA-mRNA networks were then constructed using Cytoscape software. Ten significantly differentially expressed circRNAs were also verified in the mon1 and mon9 groups by RT-qPCR. Luciferase Reporter Assay was used to verify the binding site between circRNA and its targeted miRNA. The results showed that a total of 686 DE circRNAs were identified between the mon9 and mon1 groups, of which 357 were upregulated and 329 were downregulated. Subsequently, the 467 host genes of DE circRNAs were predicted using Find_circ and CIRI software. The circRNA-miRNA-mRNA network contained 201 circRNAs, 85 miRNAs, and 581 mRNAs; the host mRNAs were associated with "muscle fiber development" and "AMPK signaling pathway" and were enriched in the FoxO signaling pathway. Competing endogenous RNA (ceRNA) network analysis showed that novel_circ_0005314, novel_circ_0005319, novel_circ_0009256, novel_circ_0009845, novel_circ_0005934 and novel_circ_0000134 may play important roles in skeletal muscle growth and development between the mon9 and mon1 groups. Luciferase Reporter Assay confirmed the combination between novel_circ_0005319 and chi-miR-199a-5p, novel_circ_0005934 and chi-miR-450-3p and novel_circ_0000134 and chi-miR-655. Our results provide specific information related to goat muscle development and a reference for the goat circRNA profile.

Effect of MiR-100-5p on proliferation and apoptosis of goat endometrial stromal cell in vitro and embryo implantation in vivo

The growth of endometrial stromal cells (ESCs) at implantation sites may be a potential factor affecting the success rate of embryo implantation. Incremental proofs demonstrated that ncRNAs (e.g. miRNAs, lncRNAs and circRNAs) were involved in various biological procedures, including proliferation and apoptosis. In this study, the role of miR‐100‐5p on proliferation and apoptosis of goat ESCs in vitro and embryo implantation in vivo was determined. The mRNA expression of miR‐100‐5p was significantly inhibited in the receptive phase (RE) rather than in the pre‐receptive phase (PE). Overexpression of miR‐100‐5p suppressed ESCs proliferation and induced apoptosis. The molecular target of MiR‐100‐5p, HOXA1, was confirmed by 3′‐UTR assays. Meanwhile, the product of HOXA1 mRNA RT‐PCR increased in the RE more than that in the PE. The HOXA1‐siRNA exerted significant negative effects on growth arrest. Instead, incubation of ESCs with miR‐100‐5p inhibitor or overexpressed HOXA1 promoted the cell proliferation. In addition, Circ‐9110 which acted as a sponge for miR‐100‐5p reversed the relevant biological effects of miR‐100‐5p. The intrinsic apoptosis pathway was suppressed in ESCs, revealing a crosstalk between Circ‐9110/miR‐100‐5p/HOXA1 axis, PI3K/AKT/mTOR, and ERK1/2 pathways. To further evaluate the progress in study on embryo implantation regulating mechanism of miR‐100‐5p in vivo, the pinopodes of two phases were observed and analysed, suggesting that, as similar as in situ, miR‐100‐5p was involved in significantly regulating embryo implantation in vivo. Mechanistically, miR‐100‐5p performed its embryo implantation function through regulation of PI3K/AKT/mTOR and ERK1/2 pathways by targeting Circ‐9110/miR‐100‐5p/HOXA1 axis in vivo.

Screening of cashmere fineness-related genes and their ceRNA network construction in cashmere goats

Competitive endogenous RNA (ceRNA) is a transcript that can be mutually regulated at the post-transcriptional level by competing shared miRNAs. The ceRNA network connects the function of protein-encoded mRNA with the function of non-coding RNA, such as microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). However, compared with the ceRNA, the identification and combined analysis of lncRNAs, mRNAs, miRNAs, and circRNAs in the cashmere fineness have not been completed. Using RNA-seq technology, we first identified the miRNAs presented in Liaoning Cashmere Goat (LCG) skin, and then analyzed the mRNAs, lncRNAs, circRNAs expressed in LCG and Inner Mongolia cashmere goat (MCG) skin. As a result, 464 known and 45 new miRNAs were identified in LCG skin. In LCG and MCG skin, 1222 differentially expressed mRNAs were identified, 170 differentially expressed lncRNAs and 32 differentially expressed circRNAs were obtained. Then, qRT-PCR was used to confirm further the representative lncRNAs, mRNAs, circRNAs and miRNAs. In addition, miRanda predicted the relationships of ceRNA regulatory network among lncRNAs, circRNAs, miRNAs and mRNAs, the potential regulatory effects were investigated by Go and KEGG analysis. Through the screening and analysis of the results, the ceRNA network regulating cashmere fineness was constructed. LncRNA MSTRG14109.1 and circRNA452 were competed with miRNA-2330 to regulated the expression of TCHH, KRT35 and JUNB, which may provide a potential basis for further research on the process of regulating the cashmere fineness.

Targeting the redox imbalance in mitochondria: A novel mode for cancer therapy

Changes in reactive oxygen species (ROS) levels affect many aspects of cell behavior. During carcinogenesis, moderate ROS production modifies gene expression to alter cell function, elevating metabolic activity and ROS. To avoid extreme ROS-activated death, cancer cells increase antioxidative capacity, regulating sustained ROS levels that promote growth. Anticancer therapies are exploring inducing supranormal, cytotoxic oxidative stress levels either inhibiting antioxidative capacity or promoting excess ROS to selectively destroy cancer cells, triggering mechanisms such as apoptosis, autophagy, necrosis, or ferroptosis. This review exemplifies pro-oxidants (natural/synthetic/repurposed drugs) and their clinical significance as cancer therapies providing revolutionary approaches.

Knockdown of circ_0001883 may inhibit epithelial-mesenchymal transition in laryngeal squamous cell carcinoma via the miR-125-5p/PI3K/AKT axis

Laryngeal squamous cell carcinoma (LSCC) is a malignant tumor with increasing incidence and poor prognosis. Circular RNAs (circRNAs) are known to modulate tumorigenesis and cancer development that may function through microRNAs (miRs). The aim of the present study was to investigate the functional roles of circ_0001883 in LSCC and the underlying molecular mechanism. The expression of circ_0001883 was upregulated and measured using reverse transcription-quantitative PCR (RT-qPCR) and RNase R. miR-125b-5p expression was downregulated in LSCC tissues and cells as determined using RT-qPCR. Subsequently, knockdown of circ_0001883 inhibited LSCC cell migration, invasion and epithelial-mesenchymal transition (EMT), which were tested by wound healing assays, Transwell assays and western blotting, respectively. Bioinformatics analysis predicted that circ_0001883 was a sponge of miR-125b-5p, which was verified using a dual-luciferase reporter assay. Knockdown of circ_0001883 played a functional role by sponging miR-125b-5p. Additionally, circ_0001883 and miR-125b-5p influenced phosphorylation of PI3K and AKT, detected via western blotting. In an in vivo study, knockdown of circ_0001883 reduced tumor volume and weight in mice, along with enhanced miR-125b-5p and E-cadherin expression levels, and decreased N-cadherin, phosphorylated (p)-PI3K/PI3K and p-AKT/AKT ratios. In conclusion, knockdown of circ_0001883 inhibited cell migration, invasion and EMT of LSCC by sponging miR-125b-5p. This is hypothesized to be via the PI3K/AKT signaling pathway, which suggested that circ_0001883 has potential for LSCC therapy.

Research progress of endometrial receptivity in patients with polycystic ovary syndrome: a systematic review

Polycystic ovary syndrome (PCOS) is a neuroendocrine heterogeneous disease that frequently occurs in women of reproductive age, causing serious damage to the fertility, quality of life, and physical and mental health of patients. The current studies have proved that satisfactory endometrial receptivity is one of the conditions that must be met during the process of spermatovum position, adhesion and invasion, as well as the subsequent blastocyst division and embryo development. Women with PCOS may suffer a series of pathological processes such as changes in the expression levels of hormones and related receptors, imbalances in the proportion of miscellaneous cytokines, insulin resistance, low-grade chronic inflammation and endometrial morphological changes, which will damage endometrial receptivity from various aspects and obstruct fertilized egg nidation and embryonic development, thus causing adverse reproductive health events including infertility and abortion. This article reviews the research progress about characteristics and related influencing factors of endometrial receptivity in PCOS patients.

Metabonomics Study on the Infertility Treated With Zishen Yutai Pills Combined With In Vitro Fertilization-embryo Transfer

Zishen Yutai Pills (ZYP) is a safe and well quality-controlled TCM preparation with promising effects in many fields of reproduction, including prevention of miscarriage, increase of pregnancy rate during in vitro fertilization-embryo transfer (IVF-ET). The plasma of patients was collected from a clinical trial, namely, “Effect of Traditional Chinese Medicine vs placebo on live births among women undergoing in vitro fertilization, a multi-center randomized controlled trial.” Plasma samples were analyzed with metabonomics method. UPLC-MS technology was used to establish the plasma metabolic fingerprint. Multivariate statistical analysis was applied for comparing the differences of plasma metabolites between ZYP group and placebo group, 44 potential metabolites were screen out and identified. Pathway analysis was conducted with database mining. Compared with placebo, chemicals were found to be significantly down-regulated on HCG trigger day and 14 days after embryo transplantation, including trihexosylceramide (d18:1/26:1), glucosylceramide(d18:1/26:0), TG(22:6/15:0/22:6), TG(22:4/20:4/18:4). Compared with placebo, some chemicals were found to be significantly up-regulated on HCG trigger day and 14 days after embryo transplantation, i.e., PIP3(16:0/16:1), PIP2(18:1/18:1), tauroursodeoxycholic acid, L-asparagine, L-glutamic acid, kynurenic acid, 11-deoxycorticosterone, melatonin glucuronide, hydroxytyrosol. These metabolites were highly enriched in pathways including sphingolipid metabolism, alanine, aspartic acid and glutamic acid metabolism, aminoacyl tRNA biosynthesis, taurine and hypotaurine metabolism. This study revealed metabolic differences between subjects administered with ZYP and placebo. Relating metabolites were identified and pathways were enriched, providing basis on the exploration on the underlying mechanisms of ZYP combined with IVF-ET in the treatment of infertility.

Meloxicam Inhibited the Proliferation of LPS-Stimulated Bovine Endometrial Epithelial Cells Through Wnt/β-Catenin and PI3K/AKT Pathways

Meloxicam is a non-steroidal anti-inflammatory drug and has been used to relieve pain and control inflammation in cows with metritis and endometritis. Meloxicam has been found to be effective in inhibiting tissue or cell growth when it is used as an anti-inflammatory therapy. However, the influence of meloxicam on bovine endometrial regeneration has not been reported. This study was to research the effect of meloxicam (0.5 and 5 μM) on the proliferation of primary bovine endometrial epithelial cells (BEECs) stimulated by Escherichia coli lipopolysaccharide. The cell viability, cell cycle, and cell proliferation were evaluated by Cell Counting Kit-8, flow cytometry, and cell scratch test, respectively. The mRNA transcriptions of prostaglandin-endoperoxide synthase 1 (PTGS1) and PTGS2, Toll-like receptor 4, and proliferation factors were detected using quantitative reverse-transcription polymerase chain reaction. The activations of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways were determined using western blot and immunofluorescence. As a result, co-treatment of meloxicam and lipopolysaccharide inhibited (P < 0.05) the cell cycle progression and reduced (P < 0.05) the cell healing rate and the mRNA level of proliferation factors as compared with the cells treated with lipopolysaccharide alone. Meloxicam decreased (P < 0.05) the lipopolysaccharide-induced PTGS2 gene expression. Neither lipopolysaccharide nor meloxicam changed PTGS1 mRNA abundance (P > 0.05). Meloxicam inhibited (P < 0.05) the lipopolysaccharide-activated Wnt/β-catenin pathway by reducing (P < 0.05) the protein levels of β-catenin, c-Myc, cyclin D1, and glycogen synthase kinase-3β and prevented the lipopolysaccharide-induced β-catenin from entering the nucleus. Meloxicam suppressed (P < 0.05) the phosphorylation of PI3K and AKT. In conclusion, meloxicam alone did not influence the cell cycle progression or the cell proliferation in BEEC but caused cell cycle arrest and inhibited cell proliferation in lipopolysaccharide-stimulated BEEC. This inhibitory effect of meloxicam was probably mediated by Wnt/β-catenin and PI3K/AKT pathways.

Two Worlds Colliding: The Interplay Between Natural Compounds and Non-Coding Transcripts in Cancer Therapy

Cancer is a devastating disease and has recently become the leading cause of death in western countries, representing an immense public health burden. When it comes to cancer treatment, chemotherapy is one of the main pillars, especially for advanced stage tumors. Over the years, natural compounds have emerged as one of the most valuable resources for new chemotherapies. It is estimated that more than half of the currently used chemotherapeutic agents are derived from natural compounds. Usually, natural compounds are discovered empirically and an important limitation of introducing new anti-cancer natural products is lack of knowledge with regard to their mechanism of action. Recent data has proven that several natural compounds may function via modulating the expression and function of non-coding RNAs (ncRNAs). NcRNAs are a heterogenous class of RNA molecules which are usually not translated into proteins but have an important role in gene expression regulation and are involved in multiple tumorigenic processes, including response/resistance to pharmacotherapy. In this review, we will discuss how natural compounds function via ncRNAs while summarizing the available data regarding their effects on over 15 types of cancer. Moreover, we will critically analyze the current advances and limitations in understanding the way natural compounds exert these health-promoting effects by acting on ncRNAs. Finally, we will propose several hypotheses that may open new avenues and perspectives regarding the interaction between natural compounds and ncRNAs, which could lead to improved natural compound-based therapeutic strategies in cancer.

Hsa_circ_0008360 sponges miR-186-5p to target CCND2 to modulate high glucose-induced vascular endothelial dysfunction

Vascular endothelial dysfunction is associated with the progress of many diseases. Circular RNAs (circRNAs) take part in the dysfunction of vascular endothelium. CircRNA hsa_circ_0008360 (circ_0008360) is dysregulated in high glucose-treated vascular endothelium, while the role and mechanism of circ_0008360 in high glucose-induced dysfunction remain unknown. Human umbilical vascular endothelium cells (HUVEC) were stimulated via high glucose. The abundances of circ_0008360, miR-186-5p and cyclin D2 (CCND2) were examined via quantitative real-time polymerase chain reaction or western blot. Vascular endothelial dysfunction was assessed via cell viability, apoptosis, migration and tube formation. The target relationship between miR-186-5p and circ_0008360 or CCND2 was analyzed via dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation analyses. Circ_0008360 expression was enhanced in high-glucose-treated HUVEC. Circ_0008360 silence mitigated high glucose-induced suppression of viability, migration, tube formation, and increase in apoptosis in HUVEC. MiR-186-5p was sponged by circ_0008360, and miR-186-5p inhibition reversed the effect of circ_0008360 silence on high glucose-induced vascular endothelial dysfunction. MiR-186-5p alleviated high glucose-induced vascular endothelial dysfunction via targeting CCND2. CCND2 interference abolished the aggravated effect of circ_0008360 on high glucose-induced vascular endothelial dysfunction. Circ_0008360 knockdown attenuated high glucose-induced vascular endothelial dysfunction via regulating miR-186-5p and CCND2, indicating circ_0008360 might act as a target for the treatment of vascular endothelial dysfunction.Abbreviations: circRNAs, circular RNAs; HUVEC, human umbilical vascular endothelium cells; CCND2, cyclin D2; XPNPEP3, X-prolyl aminopeptidase 3; ceRNAs, competing endogenous RNAs; miRNAs, microRNAs; qRT-PCR, quantitative real-time polymerase chain reaction; RIP, RNA immunoprecipitation; HIF-1α, hypoxia inducible factor 1 alpha; TLR3, toll-like receptor 3; AKAP12, A-Kinase Anchoring Protein 12; ox-LDL, oxidized low-density lipoprotein; HG, high glucose; NG, normal glucose.

hsa_circ_001946 elevates HOXA10 expression and promotes the development of endometrial receptivity via sponging miR-135b

Background

Impaired endometrial receptivity is a major reason for embryo implantation failure. There’s a paucity of information regarding the role of circRNAs on endometrial receptivity. Here, we investigated the function of hsa_circ_001946 on endometrial receptivity and its mechanisms.

Methods

A total of 50 women composing 25 with recurrent implantation failure and 25 who conceived after their implantation were recruited in this study. Expression of hsa_circ_001946, miR-135b, and HOXA10 was evaluated by quantitative RT-PCR (qRT-PCR) in biopsied endometrial tissue samples. The levels of HOXA10, and cell cycle markers (CCNB1, CDK1, and CCND1) were determined by IHC and western blotting assays. Binding relationship among miR-135b, hsa_circ_001946 and HOXA10 were confirmed by dual luciferase reporter assays and western blotting. MTT assays and cell cycle assays by FACS were employed to evaluate the proliferation and cell cycle of cells. T-HESCs were cultured with 1 µM medroxyprogesterone acetate (MPA) and 0.5 mM 8-bromoadenosine 3’:5’-cyclic monophosphate (8-Br-cAMP) to induce decidualization. The mechanisms and functions of hsa_circ_001946 on decidualization were further assessed by qRT-PCR evaluating the expression of hsa_circ_001946, miR-135b, HOXA10 and decidual markers (PRL and IGFBP1) in T-HESCs.

Results

Endometrial tissues from patients with recurrent implantation failure had lower hsa_circ_001946 expression, higher miR-135b expression, and lower HOXA10 expression. Hsa_circ_001946 promoted HOXA10 expression by sponging miR-135b in T-HESCs. Overexpression of hsa_circ_001946 restored cell proliferation and cell cycle that were disrupted by miR-135b overexpression in T-HESCs. Decidualized T-HESCs had higher hsa_circ_001946 expression, lower miR-135b expression, and higher HOXA10 expression. Overexpression of hsa_circ_001946 reversed the expression of decidual markers (PRL and IGFBP1) that were suppressed by miR-135b overexpression in T-HESCs.

Conclusions

In conclusion, our findings suggest that hsa_circ_001946 promotes cell proliferation and cell cycle process and increases expression of decidualization markers to enhance endometrial receptivity progression via sponging miR-135b and elevating HOXA10.

Hsa_circ_0056558 regulates cyclin-dependent kinase 6 by sponging microRNA-1290 to suppress the proliferation and differentiation in ankylosing spondylitis

The aims of this study was to investigate the influences of hsa_circ_0056558/miR-1290/CDK6 axis in ankylosing spondylitis (AS). The differentially expressed has_circ_0056558 and miR-1290 in AS tissue were analysed based on RNA-seq data and microarray data, respectively. qRT-PCR was performed for detection of relative expression levels of hsa_circ_0056558, miR-1290, CDK6, osteogenic differentiation markers (Runx2 and Osterix) and other inflammatory factors (TNF-α, IL-1β, and IL-6). Western blotting analysis was conducted to test the protein levels of CDK6, osteogenic differentiation markers (Runx2 and Osterix), and PI3K/AKT/NF-κB pathway-associated proteins. CCK8 assay and flow cytometry were conducted to determine cell proliferation and cell apoptotic ability, respectively. Targeted relationships were predicted by bioinformatic analysis and verified by dual-luciferase reporter assay. The differentiation of fibroblast cells was analysed by alkaline phosphatase (ALP) activity assay. Our findings revealed that the expression levels of both circ_0056558 and CDK6 in AS tissue were significantly higher than that in normal samples. Besides, hsa_circ_0056558 could suppress cell proliferation and differentiation by facilitating CDK6 expression and suppressing miR-1290 expression in AS. Over-expression of miR-1290 negatively regulated CDK6 expression to enhance cell proliferation. The protein levels of p-AKT, p-NF-κB p65, and p-IκBα were promoted by hsa_circ_0056558 or CDK6 over-expression while suppressed by miR-1290 up-regulation. In conclusion, our study demonstrated that hsa_circ_0056558 and CDK6 suppressed cell proliferation and differentiation while enhanced cell apoptosis by competitive binding to miR-1290 in AS, which might be possibly achieved by PI3K/AKT/NF-κB pathway, providing us novel therapeutic strategy for AS.

Circular RNAs: A Promising Biomarker for Endometrial Cancer

Endometrial cancer (EC) is one of the most common malignant tumors of the female reproductive tract. EC patients have high morbidity and mortality rates and remain an important cause of cancer-related morbidity and mortality worldwide. More and more studies have shown that a large number of non-coding RNAs (such as microRNAs and long non-coding RNAs) are associated with the occurrence of diseases. Circular RNAs (circRNAs) is an endogenous non-coding RNA. It has a unique covalent structure. Many studies in recent years have found circRNAs differential expression in a variety of tumor tissues compared to matched normal tissues. In endometrial carcinoma, there also are multiple circRNAs differentially expressed and therefore circRNAs perhaps can be used as a diagnostic and prognosis biomarkers of EC. In this review, we described the biogenesis, function and characteristics of circRNAs, and the circRNAs with potential influence and clinical significance on the development of EC were summarized. Adenocarcinoma is the most common form of EC, so this review focuses on endometrioid adenocarcinoma.

Current and Future Roles of Circular RNAs in Normal and Pathological Endometrium

The uterine endometrium, which lines the mammalian uterus, is essential for embryo implantation. This lining undergoes significant changes during sexual and menstrual cycles. The endometrium is also associated with hormone-related diseases such as endometriosis and endometrial cancer. Circular RNAs (circRNAs) play a role in various biological processes. Recent studies have determined that circRNAs function in both normal and pathological endometrial environments. Here, we review high-throughput studies pertaining to circRNAs as well as individual circRNAs active in the endometrium, in order to explore the myriad functions of circRNAs in the endometrium and mechanisms underlying these functions, from panoramic and individual perspectives. Owing to their abundant expression, stability, and small size, circRNAs have displayed potential usefulness as diagnostic markers and treatment targets for endometrial-related diseases. Therefore, the specific role of circRNAs in the endometrium warrants systematic investigation in the future.

Effects of Erbuzhuyu Decoction Combined with Acupuncture on Endometrial Receptivity Are Associated with the Expression of miR-494-3p

Background/Aim

Erbuzhuyu decoction (EBZYD) is a traditional Chinese medicine (TCM) formula and has been used in infertility treatment. Meanwhile, acupuncture is also used to treat female infertility. However, it is unclear whether EBZYD combined with acupuncture has better therapeutic effect. The aim of this study was to explore the effect of EBZYD combined with acupuncture and investigate its mechanism in superovulation mice.

Methods

The mice received the treatment of EBZYD, acupuncture, EBZYD combined with acupuncture, or miR-494-3p agomir combined with EBZYD and acupuncture. The blastocysts' number, endometrial microstructure, and endometrial thickness were observed, followed by the detection of endometrial receptivity-related factors, PI3K/Akt/mTOR pathway-related proteins, and miR-494-3p expression using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Luciferase reporter assay was performed to confirm the targeting relationship between HOXA10 and miR-494-3p.

Results

EBZYD combined with acupuncture treatment could increase the number of blastocysts, pinopodes, endometrial thickness, and the expression of endometrial receptivity-related factors, and the treatment effect of EBZYD combined with acupuncture was better than EBZYD or acupuncture alone. In addition, EBZYD combined with acupuncture treatment activated PI3K/Akt/mTOR pathway and inhibited the expression of miR-494-3p. HOXA10 is one of the target genes of miR-494-3p. Overexpression of miR-494-3p reversed the therapeutic effect of EBZYD combined with acupuncture and suppressed the expression of HOXA10 and the activity of PI3K/Akt/mTOR pathway.

Conclusion

This study suggests that EBZYD combined with acupuncture could improve endometrial receptivity in superovulation mice via miR-494-3p/HOXA10 axis.

MicroRNA-449a Suppresses Mouse Spermatogonia Proliferation via Inhibition of CEP55

At present, infertile patients with maturation arrest (MA) are difficult to obtain mature sperm. Spermatogenesis and its molecular mechanism are still not clear. Patients with MA and normal spermatogenesis (NS) were collected. iTRAQ-based proteomic approach was performed to reveal the different proteins between them. To validate the confidence of proteome data, the individual samples were analyzed by Western blotting (WB), quantitative polymerase chain reaction (qPCR), and immunofluorescence. The miR-449a and CEP55 were determined by Luciferase assay. Mouse GC-1 cells were transfected with CEP55 siRNAs, miR-449a mimic, or inhibitor, and cell proliferation was determined. Compared with NS, 27 proteins were differentially expressed in MA, and CEP55 protein was the most significant difference. WB and qPCR showed that CEP55 levels were significantly elevated in NS than MA. In transfected cells, overexpression of miR-449a and knockdown of CEP55 both downregulated CEP55 expression and decreased cell proliferation. miR-449a suppresses mouse spermatogonia proliferation via inhibition of CEP55.

MiR-184 Combined with STC2 Promotes Endometrial Epithelial Cell Apoptosis in Dairy Goats via RAS/RAF/MEK/ERK Pathway

The endometrium undergoes a series of complex changes to form a receptive endometrium (RE) that allows the embryo to be implanted. The inability to establish endometrial receptivity of livestock causes embryo implantation failure and considerable losses to animal husbandry. MicroRNAs (miRNAs) are a class of noncoding RNAs. Studies have found that miRNAs can regulate many critical physiological processes, including the establishment of RE during embryo implantation. miR-184 is highly expressed in the endometrial receptive period of dairy goats. This study aimed to explore the effect of miR-184 on endometrial epithelial cell (EEC) apoptosis and RE establishment. Stanniocalcin2 (STC2) is a direct target of miR-184, and miR-184 decreases the expression of STC2 in dairy goat EECs. miR-184 can activate EECs apoptosis through the RAS/RAF/MEK/ERK pathway. Additionally, miR-184 increases the expression levels of RE marker genes, such as forkhead box M1 (FOXM1) and vascular endothelial growth factor (VEGF). These findings indicate that miR-184 promotes the apoptosis of endometrial epithelial cells in dairy goats by downregulating STC2 via the RAS/RAF/MEK/ERK pathway, and that it may also regulate the establishment of RE in dairy goats.

CircRNA hsa_circRNA_0001776 inhibits proliferation and promotes apoptosis in endometrial cancer via downregulating LRIG2 by sponging miR-182

Background

Endometrial cancer (EC) is a common malignancy of the female reproductive system. Circular RNAs (circRNAs) were demonstrated to exert critical roles in cancers, including EC. This study aimed to investigate the effects of hsa_circRNA_0001776 (circ_0001776) on EC.

Methods

Real-time quantitative PCR (RT-qPCR) was used to measure circ_0001776, microRNA-182 (miR-182) and leucine-rich repeats and immunoglobulin-like domains 2 (LRIG2) expression. The diagnostic and prognostic values of circ_0001776 were identified by receiver operating characteristic (ROC) curve analysis and survival analysis, respectively. RNase R digestion was used to characterize circ_0001776, and the localization of circ_0001776 was evaluated by cell fractionation assay. Then, cell counting kit-8 (CCK-8), colony formation, and flow cytometry analysis were used to detect cell proliferation and apoptosis, respectively. The real-time glycolytic rate (ECAR) and lactate production were measured by extracellular flux analysis and a lactate assay kit, respectively. Bioinformatics analysis and dual-luciferase reporter assay were used to determine the interaction among circ_0001776, miR-182 and LRIG2. The protein expression of LRIG2 was determined by western blot. Moreover, circ_0001776 overexpression vector was used to upregulate circ_0001776 expression in an animal tumor model.

Results

Circ_0001776 and LRIG2 were downregulated, while miR-182 was upregulated in EC tissues and cells. Low expression of circ_0001776 was correlated with the 5-year survival rate of EC patients. Upregulated circ_0001776 markedly attenuated cell proliferation and glycolysis, and enhanced cell apoptosis. Besides, circ_0001776 sponged miR-182 to regulate LRIG2 expression. Circ_0001776 could suppress EC progression by miR-182/LRIG2 axis. Furthermore, we also found that circ_0001776 significantly inhibited tumor growth in vivo.

Conclusion

Our results confirmed that circ_0001776 inhibited EC tumorigenesis and progression via miR-182/LRIG2 axis, providing a potential therapeutic target for EC.

Circ_0007841 promotes the progression of multiple myeloma through targeting miR-338-3p/BRD4 signaling cascade

Background

The pathogenesis of multiple myeloma (MM) is not completely known. Uncovering the potential mechanism of MM initiation and progression is essential for identifying novel diagnostic and therapeutic targets. Herein, we explored the function and the working mechanism of circular RNA circ_0007841 in MM progression.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of circ_0007841, microRNA-338-3p (miR-338-3p) and bromodomain containing 4 (BRD4). Cell proliferation ability was analyzed through cell counting kit-8 (CCK8) assay, colony formation assay and flow cytometry. Transwell assays were conducted to measure the migration and invasion abilities of MM cells. Cell apoptosis was also assessed by flow cytometry. The interaction between miR-338-3p and circ_0007841 or BRD4 was confirmed by dual-luciferase reporter assay and RNA-pull down assay.

Results

Circ_0007841 was highly expressed in bone marrow (BM)-derived plasma cells of MM patients and MM cell lines than that in healthy volunteers and normal plasma cell line nPCs. Circ_0007841 promoted the proliferation, cell cycle and metastasis and impeded the apoptosis of MM cells. miR-338-3p was a direct target of circ_0007841 in MM cells and circ_0007841 accelerated the progression of MM through targeting miR-338-3p. BRD4 could directly bind to miR-338-3p in MM cells and miR-338-3p exerted an anti-tumor role through targeting BRD4. Circ_0007841 promoted the activation of PI3K/AKT signaling via miR-338-3p/BRD4 axis. Exosomes generated from mesenchymal stromal cells (MSCs) elevated the malignant behaviors of MM cells via circ_0007841.

Conclusion

Circ_0007841 acted as an oncogene to promote the proliferation, cell cycle and motility and restrain the apoptosis of MM cells through sequestering miR-338-3p to up-regulate the expression of BRD4.

CircularRNA-9119 protects hepatocellular carcinoma cells from apoptosis by intercepting miR-26a/JAK1/STAT3 signaling

Hepatocellular carcinoma (HCC) is a more common malignancy than the majority of cancers and ranks second in the world’s top causes of cancer-related mortality. The objective of the study was to investigate and explain how circularRNA-9119 (circ9119) regulated the properties of HCC cell lines. Cancer cells isolated from HCC patients and HCC cell lines showed clearly upregulated expression of circ9119 and Janus kinase 1 (JAK1) with decreased levels of miR-26a compared to healthy controls and normal hepatic cells. To determine the function of circ9119, circ9119 was silenced in HCC cells, resulting in significantly less proliferation of HCC cells and increasing apoptosis. Circ9119 silencing also resulted in the upregulation of miR-26a. Bioinformatics prediction and dual-luciferase reporter assays showed that circ9119 targeted miR-26a. Further studies revealed that miR-26a had the opposite effect on circ9119; the inhibition of miR-26a antagonized circ9119 silencing, leading to reduced cell proliferation and increased apoptosis, while the ectopic overexpression of miR-26a impaired cell growth. Additionally, we found that the JAK1 3′-UTR was targeted by miR-26a; a decrease in the levels of JAK1 protein and mRNA followed transfection of a miR-26a mimic. Administration of the JAK1 inhibitor, baricitinib, caused the activation of signal transducer and activator of transcription 3 (STAT3) and revealed an effect similar to that of circ9119 silencing on cell proliferation and apoptosis. These results showed that circ9119 could modulate apoptosis, and broadly, cell proliferation by competitively binding miR-26a, which targeted JAK1-STAT3, in HCC cell lines. This study is a novel description of circ9119 regulation of HCC.

Circular RNA-9119 suppresses in ovarian cancer cell viability via targeting the microRNA-21-5p-PTEN-Akt pathway

We aimed to assess the regulatory role of circular RNA (circRNA)-9119 (circ9119) in ovarian cancer (OC) cell viability. The expression of circ9119 was clearly reduced in OC tissues and cell lines, whereas the microRNA-21-5p (miR-21) levels were elevated compared with those in normal healthy control tissues and immortalized fallopian epithelial cell line FTE187. Further, circ9119 was overexpressed, causing a notable decrease in the viability and proliferation of OC cells and an increase in apoptosis. Further study showed that circ9119 upregulation resulted in a decrease in miR-21 levels. Bioinformatics forecasting (starBase and TargetScan) and dual luciferase reporter assay demonstrated that circ9119 acts as an miR-21 sponge. Recovery of miR-21 expression in circ9119-overexpressing OC cells showed that miR-21 exhibited the opposite effect on circ9119; moreover, its recovery could suppress the effects of circ9119 overexpression, recover cell proliferation, and reduce apoptosis. Furthermore, miR-21 was found to target phosphatase and tensin homologue (PTEN) 3′ untranslated region. PTEN protein and mRNA expression was reduced in OC tissues and cells, whereas it was increased on transfection with an miR-21 inhibitor. Thus, circ9119 could regulate cell proliferation and apoptosis of OC cells via by acting as an miR-21 sponge and targeting the PTEN–Akt pathway.

CircRNA-006258 Sponge-Adsorbs miR-574-5p to Regulate Cell Growth and Milk Synthesis via EVI5L in Goat Mammary Epithelial Cells

The development of the udder and the milk yield are closely related to the number and vitality of mammary epithelial cells. Many previous studies have proved that non-coding RNAs (ncRNAs) are widely involved in mammary gland development and the physiological activities of lactation. Our laboratory previous sequencing data revealed that miR-574-5p was differentially expressed during the colostrum and peak lactation stages, while the molecular mechanism of the regulatory effect of miR-574-5p on goat mammary epithelial cells (GMECs) is unclear. In this study, the targeting relationship was detected between miR-574-5p or ecotropic viral integration site 5-like (EVI5L) and circRNA-006258. The results declared that miR-574-5p induced the down-regulation of EVI5L expression at both the mRNA and protein levels, while circRNA-006258 relieved the inhibitory effect through adsorbing miR-574-5p. EVI5L blocked the G1 phase and promoted the S phase by activating the Rab23/ITGB1/TIAM1/Rac1-TGF-β/Smad pathway in GMECs. By increasing the protein expression of Bcl2 and reducing the protein expression of Bax, EVI5L promoted cell growth and inhibited apoptosis. The activation of the PI3K/AKT–mTOR signaling pathway promoted the production of triacylglycerol (TAG) and β-casein in GMECs. The circRNA–006258/miR-574-5p/EVI5L axis could regulate the cell growth and milk synthesis of GMECs by sponge-adsorbed miR-574-5p. These results would provide scientific evidence for precision animal breeding in the industry of dairy goats.

Circular RNA-9119 protects IL-1β-treated chondrocytes from apoptosis in an osteoarthritis cell model by intercepting the microRNA-26a/PTEN axis

AIMS

Osteoarthritis (OA) is a common degenerative joint disease characterized by cartilage degeneration and joint inflammation. As its pathogenesis remains unclear, there are no effective treatments established. Circular RNA (circRNA), microRNA (miRNA), and other noncoding RNAs participate in OA development; however, the effects and mechanisms of circRNA and miRNA in OA remain unknown.

MAIN METHODS

Cartilage miRNA was examined in patients with and without OA.

KEY FINDINGS

CircRNA-9119 and phosphatase and tensin homolog (PTEN) expression decreased in OA-affected cartilage and interleukin (IL)-1β-induced chondrocytes, and miR-26a expression significantly decreased in normal cells and tissues. CircRNA-9119 overexpression restored chondrocyte growth, whereas IL-1β treatment impaired chondrocyte growth. Annexin V-FITC & PI flow cytometry and Bcl-2/Bax ratio measurement indicated that the apoptosis of IL-1β-treated articular chondrocytes was decreased by circRNA-9119 upregulation. Bioinformatic prediction and the dual-luciferase reporter assay indicated that circRNA-9119 served as a miR-26a sponge and that miR-26a targeted the 3'-UTR of PTEN. Transfection of chondrocytes with a circRNA-9119-overexpressing vector revealed downregulation of miR-26a expression. Furthermore, circRNA-9119 overexpression induced PTEN expression. In addition, a miR-26a mimic induced IL-1β-induced chondrocyte apoptosis, and circRNA-9119 overexpression inhibited IL-1β-induced chondrocyte apoptosis.

SIGNIFICANCE

CircRNA-9119 is an important regulator of IL-1β-treated chondrocytes through the miR-26a/PTEN axis, possibly contributing to OA development.

miR-34a/c induce caprine endometrial epithelial cell apoptosis by regulating circ-8073/CEP55 via the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways

microRNAs (miRNAs) and circular RNAs (circRNAs) are important for endometrial receptivity establishment and embryo implantation in mammals. miR-34a and miR-34c are highly expressed in caprine receptive endometrium (RE). Herein, the functions and mechanisms of miR-34a/c in caprine endometrial epithelial cell (CEEC) apoptosis and RE establishment were investigated. miR-34a/c downregulated the expression level of centrosomal protein 55 (CEP55) and were sponged by circRNA8073 (circ-8073), thereby exhibiting a negative interaction in CEEC. miR-34a/c induced CEEC apoptosis by targeting circ-8073/CEP55 through the regulation of the RAS/RAF/MEK/ERK and phosphoitide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathways. Positive and negative feedback loops and cross-talk were documented between the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways. miR-34a/c regulated the levels of RE marker genes, including forkhead box M1, vascular endothelial growth factor, and osteopontin (OPN). These results suggest that miR-34a/c not only induce CEEC apoptosis by binding to circ-8073 and CEP55 via the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways, but may also regulate RE establishment in dairy goats.

CircularRNA-9119 promotes the proliferation of cervical cancer cells by sponging miR-126/MDM4

The aim of this study was to investigate the role of circular RNA-9119 (circ9119) in cervical cancer (CC) and the microRNA-126-3p (miR-126)-based molecular mechanism underlying CC. circ9119 and MDM4 were initially overexpressed, and miR-126 expression was found to be reduced in CC cells and tissues. A series of mimics, inhibitors, overexpressing plasmids or siRNAs were introduced into CC cells to alter the circ9119, miR-126, and MDM4 expressions. Cell-based experiments showed that silencing of circ9119 or the upregulation of miR-126 resulted in suppressed proliferation, accompanied by the induced apoptosis of CC cells. The dual-luciferase reporter assay highlighted that circ9119 functioned as an miR-126 ceRNA to increase MDM4 expression. In vivo experiments further confirmed the suppressed tumor growth caused by circ9119 silencing. Our findings demonstrated that circ9119 acts as an oncogene in CC. Our study provides evidence for targeting circ9119 for the treatment of CC.

Genome-wide identification and analysis of circular RNAs differentially expressed in the longissimus dorsi between Kazakh cattle and Xinjiang brown cattle

Xinjiang brown cattle have better meat quality than Kazakh cattle. Circular RNAs (circRNAs) are a type of RNA that can participate in the regulation of gene transcription. Whether circRNAs are differentially expressed in the longissimus dorsi between these two types of cattle and whether differentially expressed circRNAs regulate muscle formation and differentiation are still unknown. In this study, we established two RNA-seq libraries, each of which consisted of three samples. A total of 5,177 circRNAs were identified in longissimus dorsi samples from Kazakh cattle and Xinjiang brown cattle using the Illumina platform, 46 of which were differentially expressed. Fifty-five Gene Ontology terms were significantly enriched, and 12 Kyoto Encyclopedia of Genes and Genomes pathways were identified for the differentially expressed genes. Muscle biological processes were associated with the origin genes of the differentially expressed circRNAs. In addition, we randomly selected six overexpressed circRNAs and compared their levels in longissimus dorsi tissue from Kazakh cattle and Xinjiang brown cattle using RT-qPCR. Furthermore, we predicted 66 interactions among 65 circRNAs and 14 miRNAs using miRanda and established a coexpression network. A few microRNAs known for their involvement in myoblast regulation, such as miR-133b and miR-664a, were identified in this network. Notably, bta_circ_03789_1 and bta_circ_05453_1 are potential miRNA sponges that may regulate insulin-like growth factor 1 receptor expression. These findings provide an important reference for prospective investigations of the role of circRNA in longissimus muscle growth and development. This study provides a theoretical basis for targeting circRNAs to improve beef quality and taste.

Rumen-Protected Glucose Stimulates the Insulin-Like Growth Factor System and mTOR/AKT Pathway in the Endometrium of Early Postpartum Dairy Cows

This study aimed to elucidate the effects of a dietary rumen-protected glucose (RPG) addition on uterine involution through the analysis of an insulin-like growth factor (IGF) system and associated pathways in the post-natal endometrium. Twelve Holstein cows were assigned equally to two groups: a control group (CT) and an RPG group (200 g of RPG per cow per day). The plasma content of insulin-like growth factor 1 (IGF1) was determined by using the ELISA method. Expressions of IGF members, the matrix metalloproteinase, protein kinase B (AKT)/mechanistic target of rapamycin complex1 (mTOR) signaling pathway, and cell proliferation factors (proliferating cell nuclear antigen (PCNA) and Ki67) were detected using real-time polymerase chain reaction, Western blot, immunohistochemistry, and immunofluorescence, respectively. The results showed that the positive cells of PCNA and Ki67 were increased in the endometrium of RPG versus CT cows. The RPG addition significantly increased the plasma IGF1 level 14 d after delivery. The mRNA expressions of the IGF family members (IGF1, IGF2, type 1 IGF receptor (IGF1R) and IGF-binding proteins (IGFBP1, IGFBP2, IGFBP4 and IGFBP5)) were upregulated, and mRNA expressions of matrix metalloproteinase MMP3 and MMP9 were downregulated in cows from the RPG group compared with the CT group. Meanwhile, the protein expressions of IGF1, IGF2, IGF1R, IGFBP1 and IGFBP4 were upregulated in cows from the RPG group compared with the CT group. Immunohistochemical analysis identified a positive response for IGF1R and IGF2R in the endometrium of RPG versus CT cows. Furthermore, the RPG supplementation increased the protein expressions of phosphorylated (p)-AKT to total AKT and p-mTOR to total mTOR ratio in the endometrium. The current results indicated that the RPG supplementation promoted the proliferation of endometrial cells by stimulating the IGFs and mTOR/AKT pathway in the early post-natal endometrium of dairy cows.

Emerging Perspective: Role of Increased ROS and Redox Imbalance in Skin Carcinogenesis

Strategies to battle malignant tumors have always been a dynamic research endeavour. Although various vehicles (e.g., chemotherapeutic therapy, radiotherapy, surgical resection, etc.) are used for skin cancer management, they mostly remain unsatisfactory due to the complex mechanism of carcinogenesis. Increasing evidence indicates that redox imbalance and aberrant reactive oxygen species (ROS) are closely implicated in the oncogenesis of skin cancer. When ROS production goes beyond their clearance, excessive or accumulated ROS could disrupt redox balance, induce oxidative stress, and activate the altered ROS signals. These would damage cellular DNA, proteins, and lipids, further leading to gene mutation, cell hyperproliferation, and fatal lesions in cells that contribute to carcinogenesis in the skin. It has been known that ROS-mediated skin carcinogenesis involves multiple ways, including modulating related signaling pathways, changing cell metabolism, and causing the instability of the genome and epigenome. Nevertheless, the exact role of ROS in skin cancer has not been thoroughly elucidated. In spite of ROS inducing skin carcinogenesis, toxic-dose ROS could trigger cell death/apoptosis and, therefore, may be an efficient therapeutic tool to battle skin cancer. Considering the dual role of ROS in the carcinogenesis and treatment of skin cancer, it would be essential to clarify the relationship between ROS and skin cancer. Thus, in this review, we get the related data together to seek the connection between ROS and skin carcinogenesis. Besides, strategies basing on ROS to fight skin cancer are discussed.

Identification of circular RNA-associated competing endogenous RNA network in the development of cleft palate

Circular RNAs (circRNAs) serve as competing endogenous RNAs (ceRNAs) and indirectly regulate gene expression through shared microRNAs (miRNAs). However, the regulatory mechanisms of circRNA as ceRNA associated with the fusion of palatal shelves in palatogenesis are yet unclear. This study aimed to explore the potential mechanism underlying the role of circRNA as ceRNA in cleft palate (CP). First, we systematically analyzed RNA-seq and miRNA-seq data after high-throughput sequencing for embryonic palatal shelf tissues from a mouse CP model induced by maternal exposure to all-trans retinoic acid on embryonic gestation day 14.5 (E14.5). Thirty-nine circRNAs, 18 miRNAs, and 936 messenger RNAs (mRNAs) were significantly dysregulated (log₂ [fold change {FC}] > 1; P < 0.05). Thereafter, we constructed a circRNA-associated ceRNA network. Finally, we determined the circRNA_0954-miRNA-881-3p-PRKAR1α ceRNA network as a hub involved in palatogenesis. Gene Ontology analysis revealed that ceRNA-related genes were associated with facial morphogenesis and developmental gene silencing. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that ceRNA-related genes are involved in apoptosis (P < 0.05, fold enrichment >1). Quantitative reverse transcription polymerase chain reaction was performed to verify the results of ceRNA analysis. We found that the circRNA-miRNA-mRNA ceRNA network is involved in palatogenesis. The present results imply that circRNA_0954-miRNA-881-3p-PRKAR1α ceRNA network may cause dysfunctional palatal fusion and might facilitate the development of novel epigenetic biomarkers to treat CP in the future.

Analyses of circRNA profiling during the development from pre-receptive to receptive phases in the goat endometrium

BACKGROUND

Recent studies have revealed that noncoding RNAs play important regulatory roles in the formation of endometrial receptivity. Circular RNAs (circRNAs) are a universally expressed noncoding RNA species that have been recently proposed to act as miRNA sponges that directly regulate expression of target genes or parental genes.

RESULTS

We used Illumina Solexa technology to analyze the expression profiles of circRNAs in the endometrium from three goats at gestational day 5 (pre-receptive endometrium, PE) and three goats at gestational day 15 (receptive endometrium, RE). Overall, 21,813 circRNAs were identified, of which 5,925 circRNAs were specific to the RE and 9,078 were specific to the PE, which suggested high stage-specificity. Further analysis found 334 differentially expressed circRNAs in the RE compared with PE (P < 0.05). The analysis of the circRNA-miRNA interaction network further supported the idea that circRNAs act as miRNA sponges to regulate gene expression. Moreover, some circRNAs were regulated by estrogen (E2)/progesterone (P4) in endometrial epithelium cell lines (EECs) and endometrial stromal cell line (ESCs), and each circRNA molecule exhibited unique regulation characteristics with respect to E2 and P4.

CONCLUSIONS

These data provide an endometrium circRNA expression atlas corresponding to the biology of the goat receptive endometrium during embryo implantation.

Ailanthone up-regulates miR-449a to restrain acute myeloid leukemia cells growth, migration and invasion

BACKGROUND

Ailanthone (AIL) is a quassinoid isolated from traditional Chinese herbal medicine Ailanthus altissima. The anti-tumor activities of AIL have been reported in various solid tumors. This study aimed to reveal the in vitro effect of AIL on acute myeloid leukemia (AML) cells.

METHODS

The effects of AIL on five AML cell lines (KG1, HL60, U-937, THP-1 and OCI-AML2) as well as myeloid progenitor cells were evaluated by performing CCK-8 assay, flow cytometry, Transwell assay and Western blotting. KG1 and HL60 cells were transfected with miR-449a inhibitor or its negative control, and then were treated by AIL. The above mentioned assays were performed again to study the involvement of miR-449a in AIL's function.

RESULTS

AIL dose-dependently inhibited the viability of AML cells and myeloid progenitor cells. The IC50 value of AIL towards KG1 and HL60 cells was 0.58 and 0.57 μM, respectively. AIL with concentration of 0.5 μM significantly induced the apoptosis of AML cells rather than myeloid progenitor cells. Meanwhile, 0.5 μM AIL significantly reduced migration and invasion of AML cells. miR-449a was highly expressed in response to the treatment of 0.5 μM AIL. Besides this, the anti-tumor activities of AIL in AML cells were attenuated by miR-449a silence. Further, the blockage of Notch and PI3K/AKT signaling pathways induced by AIL was reversed by miR-449a silence.

CONCLUSION

AIL restrained AML cells growth, migration and invasion through up-regulation of miR-449a, and deactivation of Notch and PI3K/AKT signaling pathways.