miR-182 aids in receptive endometrium development in dairy goats by down-regulating PTN expression

CREB1 Is Involved in miR-134-5p-Mediated Endometrial Stromal Cell Proliferation, Apoptosis, and Autophagy

The successful establishment of endometrial receptivity is a key factor in ensuring the fertility of ewes and their economic benefits. Hu sheep have attracted attention due to their high fecundity and year-round estrus. In this study, we found that in the luteal phase, the uterine gland density, uterine coefficient, and number of uterine caruncles of high-fertility Hu sheep were higher than those of low-fertility Hu sheep. Thousands of differentially expressed genes were identified in the endometrium of Hu sheep with different fertility potential using RNA sequencing (RNA-Seq). Several genes involved in endometrial receptivity were screened using bioinformatics analysis. The qRT-PCR analysis further revealed the differential expression of cAMP reactive element binding protein-1 (CREB1) in the Hu sheep endometrium during the estrous cycle. Functionally, our results suggested that CREB1 significantly affected the expression level of endometrial receptivity marker genes, promoted cell proliferation by facilitating the transition from the G1 phase to the S phase, and inhibited cell apoptosis and autophagy. Moreover, we observed a negative linear correlation between miR-134-5p and CREB1 in the endometrium. In addition, CREB1 overexpression prevented the negative effect of miR-134-5p on endometrial stromal cell (ESC) growth. Taken together, these data indicated that CREB1 was regulated by miR-134-5p and may promote the establishment of uterine receptivity by regulating the function of ESCs. Moreover, this study provides new theoretical references for identifying candidate genes associated with fertility.

Pleiotrophin and metabolic disorders: insights into its role in metabolism

Pleiotrophin (PTN) is a cytokine which has been for long studied at the level of the central nervous system, however few studies focus on its role in the peripheral organs. The main aim of this review is to summarize the state of the art of what is known up to date about pleiotrophin and its implications in the main metabolic organs. In summary, pleiotrophin promotes the proliferation of preadipocytes, pancreatic β cells, as well as cells during the mammary gland development. Moreover, this cytokine is important for the structural integrity of the liver and the neuromuscular junction in the skeletal muscle. From a metabolic point of view, pleiotrophin plays a key role in the maintenance of glucose and lipid as well as whole-body insulin homeostasis and favors oxidative metabolism in the skeletal muscle. All in all, this review proposes pleiotrophin as a druggable target to prevent from the development of insulin-resistance-related pathologies.

Uterus proliferative period ceRNA network of Yunshang black goat reveals candidate genes on different kidding number trait

Pregnancy loss that occurs in the uterus is an important and widespread problem in humans and farm animals and is also a key factor affecting the fecundity of livestock. Understanding the differences in the fecundity of goats may be helpful in guiding the breeding of goats with high fecundity. In this study, we performed RNA sequencing and bioinformatics analysis to study the uterus of Yunshang black goats with high and low fecundity in the proliferative period. We identified mRNAs, long non-coding RNAs (lncRNAs), and microRNAs (miRNAs) by analyzing the uterine transcriptomes. The target genes of the identified miRNAs and lncRNAs were predicted, and miRNA-mRNA interaction and competitive endogenous RNA (ceRNA) networks were constructed. By comparisons between low- and high-fecundity groups, we identified 1,674 differentially expressed mRNAs (914 were upregulated, and 760 were downregulated), 288 differentially expressed lncRNAs (149 were upregulated, and 139 were downregulated), and 17 differentially expressed miRNAs (4 were upregulated, and 13 were downregulated). In addition, 49 miRNA-mRNA pairs and 45 miRNA-lncRNA pairs were predicted in the interaction networks. We successfully constructed a ceRNA interaction network with 108 edges that contained 19 miRNAs, 11 mRNAs, and 73 lncRNAs. Five candidate genes (PLEKHA7, FAT2, FN1, SYK, and ITPR2) that were annotated as cell adhesion or calcium membrane channel protein were identified. Our results provide the overall expression profiles of mRNAs, lncRNAs, and miRNAs in the goat uterus during the proliferative period and are a valuable reference for studies into the mechanisms associated with the high fecundity, which may be helpful to guide goat to reduce pregnancy loss.

Two oncomiRs, miR-182-5p and miR-103a-3p, Involved in Intravenous Leiomyomatosis

Leiomyomas, also referred to as fibroids, belong to the most common type of benign tumors developing in the myometrium of the uterus. Intravenous leiomyomatosis (IVL) tends to be regarded as a rare type of uterine leiomyoma. IVL tumors are characterized by muscle cell masses developing within the uterine and extrauterine venous system. The underlying mechanism responsible for the proliferation of these lesions is still unknown. The aim of the study was to investigate the expression of the two epigenetic factors, oncomiRs miR-182-5p and miR-103a-3p, in intravenous leiomyomatosis. This study was divided into two stages: initially, miR-182-5p and miR-103a-3p expression was assessed in samples coming from intravenous leiomyomatosis localized in myometrium (group I, n = 6), intravenous leiomyomatosis beyond the uterus (group II; n = 5), and the control group, i.e., intramural leiomyomas (group III; n = 9). The expression level of miR-182-5p was significantly higher in samples coming from intravenous leiomyomatosis (group I and group II) as compared to the control group (p = 0.029 and p = 0.024, respectively). In the second part of the study, the expression levels of the studied oncomiRs were compared between seven samples delivered from one woman during a four-year observation. The long-term follow-up of one patient demonstrated significantly elevated levels of both studied oncomiRs in intravenous leiomyomatosis in comparison to intramural leiomyoma samples.

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.

Expression Profile Analysis to Identify Circular RNA Expression Signatures in the Prolificacy Trait of Yunshang Black Goat Pituitary in the Estrus Cycle

The pituitary gland is an important organ. It is a complex area of the brain involved in endocrine function and reproductive regulation. However, the function of the pituitary in goat reproduction is still unclear. Herein, RNA sequencing was used to explore the expression patterns of circle RNAs (circRNAs) in the pituitary of Yunshang black goats during the various estrus phases. Then the host genes of the circRNAs were predicted, and a competing endogenous RNA (ceRNA) network was constructed. The results showed a total of 6,705 circRNAs in the pituitary of Yunshang black goats, among which 388 differentially expressed (DE) circRNAs (214 were upregulated, while 174 were downregulated) were identified between high- and low-yield Yunshang black goats in the follicular phase (HF vs. LF); moreover, 361 DE circRNAs (136 were upregulated, while 225 were downregulated) were identified between high- and low-yield Yunshang black goats in the luteal phase (HL vs. LL). There were 65 DE circRNAs targeting 40 miRNAs in the HF vs. LF comparison and 46 DE circRNAs targeting 31 miRNAs in the HL vs. LL comparison. We identified chi_circ_0030920, chi_circ_0043017, chi_circ_0008353, chi_circ_0041580, and chi_circ_0016478 as the key circRNAs through functional enrichment analysis. The ceRNA network analysis showed that chi_circ_0031209 and chi_circ_0019448 might play an important role in reproduction by influencing the expression of prolactin receptor (PRLR) in high- and low-yielding goats during the luteal phase, whereas chi_circ_0014542 regulates the expression of WNT5A during the follicular phase. Our study provided the overall expression profiles of circRNAs in the goat pituitary during the estrus phase, which provides new insight into the mechanism of high-yield goats, which can be helpful to guide goat breeding.

Effects of Resveratrol on Receptor Expression and Serum Levels of Estrogen and Progesterone in the Rat Endometritis Model

Endometritis is characterized by inflammation of the endometrial lining that leads to reduced reproductive potential. Restoring the impaired hormonal balance is an important component of endometritis treatment. The purpose of the current study was to evaluate the effects of resveratrol on estrogen and progesterone hormone status in endometritis. Mature female Sprague Dawley rats were used, and endometritis was induced by intrauterine infusion of Escherichia coli. Animals were treated with resveratrol alone or combined with marbofloxacin. Compared to the non-treated endometritis group, resveratrol treatment reduced serum oestradiol levels, increased serum progesterone levels, enhanced estrogen receptor (ER) expression in the uterine stroma, decreased ESR1 gene expression, and raised ESR2 gene expression. Resveratrol administration combined with marbofloxacin also increased ER expression in the uterine gland and progesterone receptor expression in the uterine epithelium. The findings of this study suggest that the actions of resveratrol on progesterone levels and estrogen receptor expression might be responsible for its beneficial effect in rats with endometritis.

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.

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.

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.

Pleiotrophin: Activity and mechanism

Pleiotrophin (PTN) is a potent mitogenic cytokine with a high affinity for the polysaccharide glycosaminoglycan (GAG). Although it is most strongly associated with neural development during embryogenesis and the neonatal period, its expression has also been linked to a plethora of other physiological events including cancer metastasis, angiogenesis, bone development, and inflammation. A considerable amount of research has been carried out to understand the mechanisms by which PTN regulates these events. In particular, PTN has now been shown to bind a diverse collection of receptors including many GAG-containing proteoglycans. These interactions lead to the activation of many intracellular kinases and, ultimately, activation and transformation of cells. Structural studies of PTN in complex with both GAG and domains from its non-proteoglycan receptors reveal a binding mechanism that relies on electrostatic interactions and points to PTN-induced receptor oligomerization as one of the possible ways PTN uses to control cellular functions.

A comparative analysis of gene expression induced by the embryo in the caprine endometrium

Transcriptomics is an established powerful tool to identify potential mRNAs and ncRNAs (non‐coding RNAs) for endometrial receptivity. In this study, the goat endometrium at estrus day 5 (ED5) and estrus day 15 (ED15) were selected to systematically analyse the differential expressed genes (DEGs) what were induced by the embryo. There were 1,847 genes which were significantly differential expressed in endometrium induced by the embryo at ED5, and 1,346 at ED15 (p‐value < .05). Secreted phosphoprotein 1 (SPP) was the responsive genes for embryo in the goat endometrium during estrus cycle, neurotensis (NTS) and pleiotrophin (PTN) were the responsive genes for embryo in the goat endometrium at ED5, Testin (TES) and Phosphate and Tension Homology Deleted on Chromsome ten (PTEN) at ED15. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analysis revealed cytoplasm and Endocytosis were indispensable for the endometrium development in dairy goat. In a word, this resulting view of the transcriptome greatly uncovered the global trends in mRNAs expression induced by the embryo in the endometrium of dairy goats.