GNG7 silencing promotes the proliferation and differentiation of placental cytotrophoblasts in preeclampsia rats through activation of the mTOR signaling pathway

Deciphering the Epigenetic Landscape: Placental Development and Its Role in Pregnancy Outcomes

The placenta stands out as a unique, transitory, and multifaceted organ, essential to the optimal growth and maturation of the fetus. Functioning as a vital nexus between the maternal and fetal circulatory systems, it oversees the critical exchange of nutrients and waste. This exchange is facilitated by placental cells, known as trophoblasts, which adeptly invade and remodel uterine blood vessels. Deviations in placental development underpin a slew of pregnancy complications, notably fetal growth restriction (FGR), preeclampsia (PE), recurrent spontaneous abortions (RSA), and preterm birth. Central to placental function and development is epigenetic regulation. Despite its importance, the intricate mechanisms by which epigenetics influence the placenta are not entirely elucidated. Recently, the scientific community has turned its focus to parsing out the epigenetic alterations during placental development, such as variations in promoter DNA methylation, genomic imprints, and shifts in non-coding RNA expression. By establishing correlations between epigenetic shifts in the placenta and pregnancy complications, researchers are unearthing invaluable insights into the biology and pathophysiology of these conditions. This review seeks to synthesize the latest findings on placental epigenetic regulation, spotlighting its crucial role in shaping fetal growth trajectories and development. Through this lens, we underscore the overarching significance of the placenta in the larger narrative of gestational health.

The possible effects of the MTOR polymorphisms on preeclampsia susceptibility, severity, and onset: a case-control study and in silico analysis

BACKGROUND

Preeclampsia (PE) is a gestational complication with developed hypertension and proteinuria. Evidence showed the role of mTOR in various cellular processes. Therefore, this study aimed to evaluate the effects of MTOR polymorphisms on susceptibility, severity, and onset of Preeclampsia (PE).

METHODS AND RESULTS

A total of 250 PE pregnant women and 258 age-matched control subjects were recruited in this study. To genotype MTOR polymorphisms, the PCR-RFLP method was used. The SpliceAid 2 and PROMO tools were used for in silico analysis. The maternal MTOR rs17036508T/C polymorphism was associated with PE risk in various genetic models. There was no relationship between rs2536T/C and rs2295080T/G polymorphisms and PE. The TTC and TGC haplotypes of rs2536/ rs2295080/ rs17036508 polymorphisms were significantly higher in PE women. Subgroup analysis revealed the association between the MTOR rs2295080 variant and an increased risk of Early-onset PE (EOPE). However, the MTOR rs17036508 was associated with a higher risk of EOPE and Late- Onset PE. In addition, the MTOR rs2295080 could increase the risk of severe PE. The results of the in silico analysis showed that rs17036508 disrupted several binding motifs in the mutant sequence. The PROMO database revealed that the T to C substitution leads to the loss of the TFII-I binding site in the mutant allele.

CONCLUSION

The MTOR rs17036508T/C polymorphism was associated with PE risk. There was an association between the MTOR rs2295080 variant and an increased risk of EOPE. The MTOR rs17036508T/C and rs2295080T/C variants could disrupt several binding motifs and TFII-I binding respectively.

Overcoming adaptive resistance in AML by synergistically targeting FOXO3A-GNG7-mTOR axis with FOXO3A inhibitor Gardenoside and rapamycin

Therapeutic targeting FOXO3A (a forkhead transcription factor) represents a promising strategy to suppress acute myeloid leukemia (AML). However, the effective inhibitors that target FOXO3A are lacking and the adaptive response signaling weakens the cytotoxic effect of FOXO3A depletion on AML cells. Here, we show that FOXO3A deficiency induces a compensatory response involved in the reactive activation of mTOR that leads to signaling rebound and adaptive resistance. Mitochondrial metabolism acts downstream of mTOR to provoke activation of JNK/c-JUN via reactive oxygen species (ROS). At the molecular level, FOXO3A directly binds to the promoter of G protein gamma subunit 7 (GNG7) and preserves its expression, while GNG7 interacts with mTOR and restricts phosphorylated activation of mTOR. Consequently, combinatorial inhibition of FOXO3A and mTOR show a synergistic cytotoxic effect on AML cells and prolongs survival in a mouse model of AML. Through a structure-based virtual screening, we report one potent small-molecule FOXO3A inhibitor (Gardenoside) that exhibits a strong effect of anti-FOXO3A DNA binding. Gardenoside synergizes with rapamycin to substantially reduce tumor burden and extend survival in AML patient-derived xenograft model. These results demonstrate that mTOR can mediate adaptive resistance to FOXO3A inhibition and validate a combinatorial approach for treating AML.

GNG2 acts as a tumor suppressor in breast cancer through stimulating MRAS signaling

G-protein gamma subunit 2 (GNG2) is involved in several cell signaling pathways, and is essential for cell proliferation and angiogenesis. However, the role of GNG2 in tumorigenesis and development remains unclear. In this study, 1321 differentially expressed genes (DEGs) in breast cancer (BC) tissues were screened using the GEO and TCGA databases. KEGG enrichment analysis showed that most of the enriched genes were part of the PI3K-Akt signaling pathway. We identified GNG2 from the first five DEGs, its expression was markedly reduced in all BC subtype tissues. Cox regression analysis showed that GNG2 was independently associated with overall survival in patients with luminal A and triple-negative breast cancers (TNBC). GNG2 over-expression could significantly block the cell cycle, inhibit proliferation, and promote apoptosis in BC cells in vitro. In animal studies, GNG2 over-expression inhibited the growth of BC cells. Further, we found that GNG2 significantly inhibited the activity of ERK and Akt in an MRAS-dependent manner. Importantly, GNG2 and muscle RAS oncogene homolog (MRAS) were co-localized in the cell membrane, and the fluorescence resonance energy transfer (FRET) experiment revealed that they had direct interaction. In conclusion, the interaction between GNG2 and MRAS likely inhibits Akt and ERK activity, promoting apoptosis and suppressing proliferation in BC cells. Increasing GNG2 expression or disrupting the GNG2-MRAS interaction in vivo could therefore be a potential therapeutic strategy to treat BC.

The Prognostic Value of GNG7 in Colorectal Cancer and Its Relationship With Immune Infiltration

Background: G Protein Subunit Gamma 7 (GNG7) is an important gene that regulates cell proliferation and induces apoptosis. However, the correlation between GNG7 expression and immune infiltration as well as patient prognosis of colorectal cancer (CRC) remains unclear.

Methods: The GNG7 expression differences between tumor tissues and normal tissues were explored via the Oncomine database, Tumor Immune Estimation Resource (TIMER) site and UALCAN database. Then, the influence of GNG7 on clinical prognosis were evaluated, using the PrognoScan database. In addition, the relationship between GNG7 and tumor-related immune infiltration as well as gene marker sets of immune infiltration was investigated via TIMER, TISIDB and GEPIA.

Results: We found that GNG7 expression was down-regulated in multiple malignant tumors including colorectal cancer (CRC) and the GNG7 expression was associated with tumor stage, histology subtype, lymph node metastasis and poor prognosis in colorectal cancer (CRC). In addition, the expression of GNG7 was significantly associated with infiltration level of multiple immune cells, immunomodulatory factors as well as part of the immune cell markers.

Conclusion: GNG7 displays validated prognostic value in CRC and was associated with its immune cell infiltration and immunoregulation. These results suggest that GNG7 is a potential prognostic marker and is associated with tumor immune infiltration, thus providing a new perspective for the immunotherapy of CRC.

Puerarin attenuates preeclampsia-induced trophoblast mobility loss and inflammation by modulating miR-181b-5p/RBAK axis

PROBLEM

Preeclampsia (PE) is a serious pregnancy complication characterized by inflammation and impaired trophoblast motility. Puerarin (Pue) is a functional compound with anti-PE potential. The current study aimed to explore the therapeutic effects of Pue on PE as well as the associated mechanism by focusing on the interaction between Pue and microRNAs (miRs).

METHODS OF STUDY

Human villous trophoblast HTR-8/SVneo cells were treated with TNF-α and Pue, and a change in miR expression profile was determined. The anti-PE effects of Pue were validated in rat models by measuring blood pressure, 24-h proteinuria, and cytokine levels. The mechanism was explored by focusing on miR-181b-5p/RBAK axis.

RESULTS

The induction of PE increased blood pressure and 24-h proteinuria, and induced TNF-α, IL-1β, and IL-6 levels, which was reversed by Pue. In in vitro assays, TNF-α suppressed viability, induced apoptosis and inflammatory response, and inhibited migration in trophoblasts, which was attenuated by Pue. At molecular level, the expression level of miR-181b-5p was both induced in vivo and in vitro with the development of PE symptoms, contributing to the inhibited expression of RBAK. The induced expression of miR-181b-5p under Pue treatment showed that the reinduction of miR-181b-5p counteracted the effects of Pue, indicating the key role of the miR in the protective effects of Pue against PE.

CONCLUSIONS

The current study verified the anti-PE function of Pue: the compound suppressed inflammatory response associated with PE, and improved trophoblast motility. The effects depended on the inhibition of miR-181b-5p that inhibited the expression of RBAK.

Prothioconazole induces cell cycle arrest by up-regulation of EIF4EBP1 in extravillous trophoblast cells

Prothioconazole (PTC) is a new broad-spectrum triazole antibacterial agent that is being widely used in agriculture. PTC has been linked to a number of reproductive outcomes including embryo implantation disorder; however, the exact mechanism underlying this relationship has yet to be determined. Proper trophoblast proliferation and migration is a prerequisite for successful embryo implantation. To elucidate the underlying molecular perturbations, we detect the effect of PTC on extravillous trophoblast cells proliferation and migration, and investigate its potential mechanisms. Exposure to different concentrations of PTC (0-500 μM) significantly inhibited the cell viability and migration ability (5 μM PTC exposure), and also caused the cell cycle arrest at the lowest dose (1 μM PTC exposure). Transcriptome analysis revealed that PTC exposure disturbed multiple biological processes including cell cycle and apoptosis, consistent with cell phenotype. Specifically, eukaryotic translation initiation factor 4E binding protein 1 (EIF4EBP1, 4E-BP1) was identified as up-regulated in PTC exposure group and knockdown of EIF4EBP1, and attenuated the G1 phase arrest induced by PTC exposure. In summary, our data demonstrated that 4E-BP1 participated in PTC-induced cell cycle arrest in extravillous trophoblast cells by regulating cyclin D1. These findings shed light on the potential adverse effect of PTC exposure on the embryo implantation.

The MEG3 lncRNA promotes trophoblastic cell growth and invasiveness in preeclampsia by acting as a sponge for miR-21, which regulates BMPR2 levels

Preeclampsia (PE) is one of the leading causes of maternal morbidity and mortality in pregnant women. This study aimed to investigate the potential impact and regulatory mechanisms of bone morphogenetic protein receptor 2 (BMPR2) on the progression of PE. We obtained placental tissues from pregnant women with PE and normal pregnant women, and the results showed that BMPR2 was expressed at low levels in the tissue from PE women. Genetic knockdown of BMPR2 increased the proliferation and invasion of cultured trophoblast cells, whereas its overexpression reduced these characteristics. Bioinformatics analysis and luciferase reporter gene assays confirmed that BMPR2 is a direct target of miR-21. Overexpression of a miR-21 inhibitor promoted the growth and invasiveness of trophoblast cells, whereas the opposite results were observed for the miR-21 mimic. Furthermore, miR-21 was sponged by the lncRNA MEG3, and shRNA inhibition of MEG3 reduced trophoblast cell growth and invasiveness. miR-21 was upregulated in the tissues from PE women, whereas MEG3 was downregulated, and the two were negatively correlated. Collectively, this study demonstrates that the lncRNA MEG3 acts as a sponge for miR-21, which regulates BMPR2 expression and promotes trophoblast cell proliferation and invasiveness, thereby preventing the development of PE. These findings provide novel insight into a targeted therapy that could be used to treat or prevent the development of PE.

miR-146a modulates TLR1/2 and 4 induced inflammation and links it with proliferation and lipid production via the indirect regulation of GNG7 in human SZ95 sebocytes

Activation of Toll-like receptors (TLR) 1/2 and 4 are central in inducing inflammation in sebocytes by regulating the expression of protein coding mRNAs, however the microRNA (miRNA) profile in response to TLR activation and thus the possible role of miRNAs in modulating sebocyte functions has not been elucidated. In this work we identified miR-146a to have the highest induction in the TLR1/2 and 4 activated SZ95 sebocytes and found that its increased levels led to the down-regulation of IL-8 secretion, decreased the chemoattractant potential and stimulated the proliferation of sebocytes. Assessing the gene expression profile of SZ95 sebocytes treated with a miR-146a inhibitor, the induction of GNG7 was one of the highest, while when cells were treated with a miR-146a mimic, the expression of GNG7 was down-regulated. These findings correlated with our in situ hybridization results, that compared with control, miR-146a showed an increased, while GNG7 a decreased expression in sebaceous glands of acne samples. Further studies revealed, that when inhibiting the levels of GNG7 in SZ95 sebocytes, cells increased their lipid content and decreased their proliferation. Our findings suggest, that miR-146a could be a potential player in acne pathogenesis by regulating inflammation, inducing proliferation and, through the indirect down-regulation of GNG7, promoting the lipid production of sebocytes.

Osthole Inhibits Breast Cancer Progression through Upregulating Tumor Suppressor GNG7

Osthole (OST) is a plant-derived compound that can inhibit the proliferation of tumor cells and has a tumor-suppressive effect in multiple types of cancers. However, the mechanisms of OST-mediated breast cancer (BrCa) inhibition were still largely unknown. In this study, we made full use of the GSE85871 dataset to identify potential targets of OST in BrCa via multiple bioinformatics analysis. Next, a series of in vitro experiments were conducted to check the role of GNG7 in BrCa and the relationship between OST and GNG7. Through a series of bioinformatics analyses, GNG7 was identified as a potential target of OST, which could be significant upregulated by OST exposure in BrCa cells. Besides, GNG7 was lowly expressed in BrCa tissues compared with normal breast tissues, and BrCa patients with low GNG7 expression had shorter overall survival (OS) and relapse-free survival (RFS) compared with those with high GNG7 expression. Moreover, GNG7 silencing significantly enhanced cell proliferation and inhibited apoptosis, and exogenous overexpression of GNG7 showed reverse effects on BrCa cells. Last but not least, GNG7 inhibition could notably rescue OST-mediated cytotoxic effects. In summary, we identified GNG7 as a novel target for OST in BrCa and a potential tumor suppressor. Thus, OST could be therapeutically beneficial for BrCa through a GNG7-dependent mechanism.

Elevated MicroRNA 183 Impairs Trophoblast Migration and Invasiveness by Downregulating FOXP1 Expression and Elevating GNG7 Expression during Preeclampsia

Preeclampsia (PE) is a hypertensive disorder of uncertain etiology that is the leading cause of maternal and fetal morbidity or mortality. The dysregulation of microRNAs (miRNAs) has been highlighted as a potential factor involved in the development of PE. Therefore, our study investigated a novel miRNA, miRNA 183 (miR-183), and its underlying association with PE. Expression of miR-183, forkhead box P1 (FOXP1), and G protein subunit gamma 7 (GNG7) in placental tissues of patients with PE was determined. Gain- and loss-of-function experiments were conducted to explore modulatory effects of miR-183, FOXP1, and GNG7 on the viability, invasion, and angiogenesis of trophoblast cells in PE. Finally, we undertook in vivo studies to explore effects of FOXP1 in the PE model. The results revealed suppressed expression of FOXP1 and significant elevations in miR-183 and GNG7 expression in placental tissues of PE patients. FOXP1 was observed to promote proliferation, invasion, and angiogenesis in human chorionic trophoblastic cells. miR-183 resulted in depletion of FOXP1 expression, while FOXP1 was capable of restraining GNG7 expression and promoting the mTOR pathway. The findings confirmed the effects of FOXP1 on PE. In conclusion, miR-183 exhibits an inhibitory role in PE through suppression of FOXP1 and upregulation of GNG7.

Long Non-Coding RNA Nuclear-Enriched Abundant Transcript 1 (NEAT1) Represses Proliferation of Trophoblast Cells in Rats with Preeclampsia via the MicroRNA-373/FLT1 Axis

Background

Preeclampsia (PE) remains one of the primary causes of maternal morbidity and mortality worldwide. This study was designed to investigate the relevance of long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) and downstream molecules in trophoblast cell proliferation and apoptosis.

Material/Methods

NEAT1 expression in the placental tissues of rats with PE was analyzed by reverse transcriptionquantitative polymerase chain reaction. The role of NEAT in trophoblast cell proliferation, migration, invasion, and apoptosis was assessed by transfecting pcDNA-NEAT1 and siRNA-NEAT1 into trophoblast cells. The microRNA (miRNA) binding to NEAT1 and the genes targeted by the screened miRNAs were predicted by Starbase, and the mechanism of action of NEAT1 in PE was further investigated.

Results

The expression of NEAT1 lncRNA was markedly higher in placental samples of PE than control rats. Ectopic expression of NEAT1 repressed trophoblast cell proliferation, migration, invasion, and colony formation, but facilitated cell apoptosis, whereas NEAT1 downregulation resulted in the opposite effects. NEAT1 was found to act as a molecular sponge for miR-373, regulating Fms-like tyrosine kinase-1 (FLT-1) to modulate PE development.

Conclusions

NEAT1 may contribute to PE development by regulating trophoblast cell proliferation and apoptosis. These findings may provide a new perspective for understanding the etiology and pathogenesis of PE.

Pathogenesis of Preeclampsia and Therapeutic Approaches Targeting the Placenta

Preeclampsia (PE) is a serious pregnancy complication, affecting about 5–7% of pregnancies worldwide and is characterized by hypertension and damage to multiple maternal organs, primarily the liver and kidneys. PE usually begins after 20 weeks’ gestation and, if left untreated, can lead to serious complications and lifelong disabilities—even death—in both the mother and the infant. As delivery is the only cure for the disease, treatment is primarily focused on the management of blood pressure and other clinical symptoms. The pathogenesis of PE is still not clear. Abnormal spiral artery remodeling, placental ischemia and a resulting increase in the circulating levels of vascular endothelial growth factor receptor-1 (VEGFR-1), also called soluble fms-like tyrosine kinase-1 (sFlt-1), are believed to be among the primary pathologies associated with PE. sFlt-1 is produced mainly in the placenta during pregnancy and acts as a decoy receptor, binding to free VEGF (VEGF-A) and placental growth factor (PlGF), resulting in the decreased bioavailability of each to target cells. Despite the pathogenic effects of increased sFlt-1 on the maternal vasculature, recent studies from our laboratory and others have strongly indicated that the increase in sFlt-1 in PE may fulfill critical protective functions in preeclamptic pregnancies. Thus, further studies on the roles of sFlt-1 in normal and preeclamptic pregnancies are warranted for the development of therapeutic strategies targeting VEGF signaling for the treatment of PE. Another impediment to the treatment of PE is the lack of suitable methods for delivery of cargo to placental cells, as PE is believed to be of placental origin and most available therapies for PE adversely impact both the mother and the fetus. The present review discusses the pathogenesis of PE, the complex role of sFlt-1 in maternal disease and fetal protection, and the recently developed placenta-targeted drug delivery system for the potential treatment of PE with candidate therapeutic agents.

Role of LAMA4 Gene in Regulating Extravillous Trophoblasts in Pathogenesis of Preeclampsia

Background

Preeclampsia is a severe obstetric complication affecting the health of pregnant women. The aim of this study was to determine the effect of LAMA4 gene on extravillous trophoblasts (EVTs) in the pathogenesis of preeclampsia and its possible regulatory mechanism.

Material/Methods

HTR-8/SVneo cells were transfected with small-interfering ribonucleic acid (siRNA) targeting LAMA. The LAMA4 protein level was detected via Western blotting. Moreover, the influences of LAMA4 gene on the proliferation, migration and invasion of HTR-8/SVneo cells were detected via cell counting kit-8 (CCK-8) assay and Transwell assay. We also assessed the influences of LAMA4 gene on vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) messenger RNA (mRNA) levels in HTR-8/SVneo cells as measured by reverse transcription-polymerase chain reaction (RT-PCR).

Results

The cell lines with downregulation of LAMA4 gene were successfully established by transfection. Compared with those in the normal group, the proliferation, migration, and invasion of HTR-8/SVneo cells declined, the VEGF mRNA level was reduced, and the sFlt-1 mRNA level was increased in the silencing group.

Conclusions

Downregulation of the LAMA4 gene inhibits the proliferation, migration, and invasion of EVT to suppress the expression of vascular factors, leading to the occurrence or development of preeclampsia. Our data provide new insights into modulation of LAMA4 expression as a potential target for therapy against preeclampsia. Further research is needed on placenta sampling from pre-eclamptic pregnancies to validate the effect of LAMA4 expression compared to control pregnancies.