Increased apoptosis rate of human decidual cells and cytotrophoblasts in patients with recurrent spontaneous abortion as a result of abnormal expression of CDKN1A and Bax

The effect and mechanism of low-molecular-weight heparin on the decidualization of stromal cells in early pregnancy

OBJECTIVE

This study aimed to analyze the effect of low-molecular-weight heparin (LMWH) on the decidualization of stromal cells in early pregnancy and explore the effect of LMWH on pregnancy outcomes.

METHODS

Recurrent spontaneous abortion (RSA) mouse model (CBA/J × DBA/2) and normal pregnant mouse model (CBA/J × BALB/c) were established. The female mice were checked for a mucus plug twice daily to identify a potential pregnancy. When a mucus plug was found, conception was considered to have occurred 12 h previously. The pregnant mice were divided randomly into a normal pregnancy control group, an RSA model group, and an RSA + LMWH experimental group (n = 10 mice in each group). Halfway through the 12th day of pregnancy, the embryonic loss of the mice was observed; a real-time quantitative polymerase chain reaction was used to detect the messenger ribonucleic acid (mRNA) expressions of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) in the decidua of the mice. Additionally, the decidual tissues of patients with RSA and those of normal women in early pregnancy who required artificial abortion were collected and divided into an RSA group and a control group. Decidual stromal cells were isolated and cultured to compare cell proliferation between the two groups, and cellular migration and invasion were detected by membrane stromal cells. Western blotting was used to detect the protein expressions of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteinase- (MMP) 2, and MMP-7 in stromal cells treated with LMWH.

RESULTS

Compared with the RSA group, LMWH significantly reduced the pregnancy loss rate in the RSA mice (p < 0.05). Compared with the RSA group, the LMWH + RSA group had significantly higher expression levels of PRL and IGFBP1 mRNA (p < 0.01). LMWH promoted the proliferation, migration, and invasion of human decidual stromal cells; compared with the control group, the expression levels of MMP-2, MMP-7, cyclin D1, and PCNA proteins in the decidual stromal cells of the LMWH group increased (p < 0.05).

CONCLUSIONS

The use of LMWH can improve pregnancy outcomes by enhancing the proliferation and migration of stromal cells in early pregnancy and the decidualization of stromal cells.

Exploring melatonin's multifaceted role in female reproductive health: From follicular development to lactation and its therapeutic potential in obstetric syndromes

BACKGROUND

Melatonin is mainly secreted by the pineal gland during darkness and regulates biological rhythms through its receptors in the suprachiasmatic nucleus of the hypothalamus. In addition, it also plays a role in the reproductive system by affecting the function of the hypothalamic-pituitary-gonadal axis, and by acting as a free radical scavenger thus contributing to the maintenance of the optimal physiological state of the gonads. Besides, melatonin can freely cross the placenta to influence fetal development. However, there is still a lack of overall understanding of the role of melatonin in the reproductive cycle of female mammals.

AIM OF REVIEW

Here we focus the role of melatonin in female reproduction from follicular development to delivery as well as the relationship between melatonin and lactation. We further summarize the potential role of melatonin in the treatment of preeclampsia, polycystic ovary syndrome, endometriosis, and ovarian aging.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Understanding the physiological role of melatonin in female reproductive processes will contribute to the advancement of human fertility and reproductive medicine research.

Viral-induced inflammation can lead to adverse pregnancy outcomes

INTRODUCTION

Parvoviruses are DNA viruses of small size. There have been a number of reports indicating the possible effects of B19 infections during pregnancy. These effects include spontaneous abortions, stillbirth, fetal damage, and quite often, fetal anemia with hydrops fetalis.

JAZF1 safeguards human endometrial stromal cells survival and decidualization by repressing the transcription of G0S2

Decidualization of human endometrial stromal cells (hESCs) is essential for the maintenance of pregnancy, which depends on the fine-tuned regulation of hESCs survival, and its perturbation contributes to pregnancy loss. However, the underlying mechanisms responsible for functional deficits in decidua from recurrent spontaneous abortion (RSA) patients have not been elucidated. Here, we observed that JAZF1 was significantly downregulated in stromal cells from RSA decidua. JAZF1 depletion in hESCs resulted in defective decidualization and cell death through apoptosis. Further experiments uncovered G0S2 as a important driver of hESCs apoptosis and decidualization, whose transcription was repressed by JAZF1 via interaction with G0S2 activator Purβ. Moreover, the pattern of low JAZF1, high G0S2 and excessive apoptosis in decidua were consistently observed in RSA patients. Collectively, our findings demonstrate that JAZF1 governs hESCs survival and decidualization by repressing G0S2 transcription via restricting the activity of Purβ, and highlight the clinical implications of these mechanisms in the pathology of RSA.

LDHA deficiency inhibits trophoblast proliferation via the PI3K/AKT/FOXO1/CyclinD1 signaling pathway in unexplained recurrent spontaneous abortion

Dysregulated trophoblast proliferation, invasion, and apoptosis may cause several pregnancy-associated complications, such as unexplained recurrent spontaneous abortion (URSA). Recent studies have shown that metabolic abnormalities, including glycolysis inhibition, may dysregulate trophoblast function, leading to URSA. However, the underlying mechanisms remain unclear. Herein, we found that lactate dehydrogenase A (LDHA), a key enzyme in glycolysis, was significantly reduced in the placental villus of URSA patients. The human trophoblast cell line HTR-8/SVneo was used to investigate the possible LDHA-mediated regulation of trophoblast function. LDHA knockdown in HTR-8/SVneo cells induced G0/G1 phase arrest and increased apoptosis, whereas LDHA overexpression reversed these effects. Next, RNA sequencing combined with Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the PI3K/AKT signaling pathway is potentially affected by downstream genes of LDHA. Especially, we found that LDHA knockdown decreased the phosphorylation levels of PI3K, AKT, and FOXO1, resulting in a significant downregulation of CyclinD1. In addition, treatment with an AKT inhibitor or FOXO1 inhibitor also verified that the PI3K/AKT/FOXO1 signaling pathway influenced the gene expression of CyclinD1 in trophoblast. Moreover, p-AKT expression correlated positively with LDHA expression in syncytiotrophoblasts and extravillous trophoblasts in first-trimester villus. Collectively, this study revealed a new regulatory pathway for LDHA/PI3K/AKT/FOXO1/CyclinD1 in the trophoblast cell cycle and proliferation.

Perfluorooctanoic acid exposure in early pregnancy induces oxidative stress in mice uterus and liver

This study aimed to explore the mechanism of perfluorooctanoic acid (PFOA) toxicity on the uterus and liver of mice during early pregnancy. Pregnant mice were given 0, 1, 5, 10, 20, and 40 mg/kg PFOA daily by gavage from gestational day (GD) 1-7 and sacrificed on GD 9. Subsequently, several toxicity parameters were evaluated, including the uterus and liver weights, liver and uterine indexes, histopathological changes of the liver and uterus, and levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the liver. We also determined the expressions of FAS, FASL, Bax, Bcl-2, and Caspase-3 in decidual cells by immunohistochemistry and the TUNEL assay to detect apoptosis uterine cells. The results showed that PFOA increased the liver weights and reduced the uterus index in a dose-dependent manner. With increasing doses of PFOA, the levels of SOD and GSH-Px were significantly decreased, and MDA increased substantially in liver tissue. 20 mg/kg and 40 mg/kg of PFOA caused more substantial harm to the uterus, thus a higher probability for congestion and resorption. The expression of FAS, FASL, Bax, and Caspase-3 in decidual cells of the uterus in the PFOA treatment groups significantly increased in a dose-dependent manner. The expression of Bcl-2 was downregulated, decreasing the Bcl-2/Bax ratio. At gestation day 9, the control group had significantly fewer apoptotic cells in the uterus and shallower staining than the 40 mg/kg PFOA group. The findings of this study suggest that oxidative damage may be one of the mechanisms by which PFOA induces liver toxicity, and a subsequent increase in uterine cell apoptosis may cause embryo loss or damage.

Pulmonary Alveolar Stem Cell Senescence, Apoptosis, and Differentiation by p53-Dependent and -Independent Mechanisms in Telomerase-Deficient Mice

Pulmonary premature ageing and fibrogenesis as in idiopathic pulmonary fibrosis (IPF) occur with the DNA damage response in lungs deficient of telomerase. The molecular mechanism mediating pulmonary alveolar cell fates remains to be investigated. The present study shows that naturally occurring ageing is associated with the DNA damage response (DDR) and activation of the p53 signalling pathway. Telomerase deficiency induced by telomerase RNA component (TERC) knockout (KO) accelerates not only replicative senescence but also altered differentiation and apoptosis of the pulmonary alveolar stem cells (AEC2) in association with increased innate immune natural killer (NK) cells in TERC KO mice. TERC KO results in increased senescence-associated heterochromatin foci (SAHF) marker HP1γ, p21, p16, and apoptosis-associated cleaved caspase-3 in AEC2. However, additional deficiency of the tumour suppressor p53 in the Trp53-/- allele of the late generation of TERC KO mice attenuates the increased senescent and apoptotic markers significantly. Moreover, p53 deficiency has no significant effect on the increased gene expression of T1α (a marker of terminal differentiated AEC1) in AEC2 of the late generation of TERC KO mice. These findings demonstrate that, in natural ageing or premature ageing accelerated by telomere shortening, pulmonary senescence and IPF develop with alveolar stem cell p53-dependent premature replicative senescence, apoptosis, and p53-independent differentiation, resulting in pulmonary senescence-associated low-grade inflammation (SALI). Our studies indicate a natural ageing-associated molecular mechanism of telomerase deficiency-induced telomere DDR and SALI in pulmonary ageing and IPF.

Aberrant expression of BAX, MEG3, and miR-214-3P genes in recurrent pregnancy loss

AIMS

Recurrent pregnancy loss (RPL), with unknown causes, is one of the most common challenges facing pregnancy. Apoptotic signaling pathways are involved in the normal and abnormal pregnancy process. Despite the evidence pointing toward the aberrant expression of apoptotic and apoptotic-related genes in pregnancy complications, the involvement of these genes in RPL remains to be elucidated. This study aimed to investigate the expression levels of BAX, MEG3, and miR-214-3p (as a microRNA), and their associations in an Iranian population.

MATERIALS AND METHODS

Following the extraction of RNA from blood samples of RPL patients and controls, quantitative expression levels of BAX, MEG3, and miR-214-3p genes were analyzed by real-time RT-PCR.

RESULTS

The findings showed that the expression levels of BAX and miRNA-214-3p were significantly higher in the blood samples of RPL patients than in control samples. In contrast, the expression of MEG3 was significantly down-regulated in women RPL. Furthermore, altered expressions of MEG3 and miRNA-214-3p are associated with their target gene BAX, where the BAX expression is positively and negatively correlated with the expressions of has-miR-214-3P and MEG3, respectively. ROC curve evaluation demonstrated the highest specificity and diagnostic value for miR-214-3p expression in distinguishing RPL samples from the healthy controls.

CONCLUSIONS

These data indicated that the aberrant expression of BAX, MEG3, miRNA-214-3p genes in RPL patients could provide new insights into the biological characteristics and related pathways of differentially expressed genes, which could help as potential diagnostic biomarkers and a better understanding of the molecular mechanisms of RPL.

MNSFβ Promotes the Proliferation and Migration of Human Extravillous Trophoblast Cells and the Villus Expression Level of MNSFβ Is Decreased in Recurrent Miscarriage Patients

AIMS

The invasion of extravillous trophoblast (EVT) cells into maternal decidua is essential for the establishment and maintenance of pregnancy. Derangement of EVT cell invasion might cause pregnancy complications including recurrent miscarriage (RM). We previously reported that deficiency of monoclonal nonspecific suppressor factor beta (MNSFβ) led to the early pregnancy failure in mice and the decidual MNSFβ expression level in RM patients was significantly decreased, but the underlying molecular mechanism of the role that MNSFβ played at the maternal-fetal interface remains unclear. Thus, in the present study, we determined effects of downregulated MNSFβ expression on human EVT cell activities.

METHODS

The MNSFβ expression in first-trimester human decidual and placental villus tissues was detected, respectively, by immunofluorescence or immunohistochemical analyses. The MNSFβ expression level in the immortalized first-trimester human EVT cell line HTR8/SVneo was downregulated by transfecting the small interfering RNA against MNSFβ and upregulated by transfecting the recombinant pDsRed-MNSFβ plasmids. The proliferation, migration, invasion, and apoptosis activities of HTR8/SVneo cells were, respectively, determined by cytometry assay, scratch test, transwell assay, and FITC/PI staining. The expression levels of P53, RhoA, Bcl-2, Bax, and MMP-9 in HTR8/SVneo cells, as well as the expression levels of MNSFβ and RhoA in placental villi of RM patients and physically normal pregnant women (NP), were examined by Western blot analysis.

RESULTS

MNSFβ protein signals were observed in first-trimester human villus and extravillous trophoblast cells. The downregulated MNSFβ expression significantly attenuated the proliferation, migration, and invasion abilities of HTR8/SVneo cells, accompanied with the obviously decreased expression levels of P53, RhoA, Bcl-2, Bax, and MMP-9, whereas the upregulated MNSFβ expression in HTR8/SVneo cells represented the inverse effects. Furthermore, expression levels of MNSFβ and RhoA in first-trimester human placental villus tissues of RM patients were significantly decreased compared to that of NP women.

CONCLUSION

These data suggested that MNSFβ promotes proliferation and migration of human EVT cells, probably via the P53 signaling pathway, and the deficiency of MNSFβ in placental villi might lead to early pregnancy loss by reducing proliferation and invasion activities of EVTs.

Long non-coding RNA H19 regulates Bcl-2, Bax and phospholipid hydroperoxide glutathione peroxidase expression in spontaneous abortion

Spontaneous abortion (SA) is the most frequently occurring pregnancy disorder and is a serious threat to women's health. Identifying novel risk factors and the molecular mechanisms underlying SA are important. The present study reported that the RNA expression levels of long non-coding RNA H19 were lower in SA group compared with those in the control group, and the expression of Bax was increased and levels of Bcl-2 and phospholipid hydroperoxide glutathione peroxidase (GPX4) were decreased in SA group at both the mRNA and protein levels. H19 expression was positively correlated with Bcl-2 and GPX4 expression and negatively linked with Bax levels. It was demonstrated that silencing H19 downregulated Bcl-2 and GPX4 expression and upregulated Bax expression at both the mRNA and protein levels in HTR-8/SVneo trophoblast cells. In conclusion, the present findings suggested that H19 has important roles in SA by promoting apoptosis and ferroptosis.

PSMD12 promotes breast cancer growth via inhibiting the expression of pro-apoptotic genes

Breast cancer (BC), the most frequent cancer in women worldwide, is extremely heterogeneous. For effective and precise treatment and to cope with drug resistance in BC, we need to find more therapeutic molecular targets. In this study, we found that the Proteasome 26S Subunit, Non-ATPase 12 (PSMD12) was upregulated in BC samples, its expression was heterogeneous among different cell lines, and high levels of PSMD12 were related to poor prognosis of BC patients. Notably, the expression of PSMD12 increased in the nucleus. Cytological experiments revealed that PSMD12 knockdown inhibited cell growth and migration, and a genome-wide CRISPR-Cas9 knockout (GeCKO) screen also confirmed that PSMD12 is a crucial gene for the growth of BC cells. Flow cytometry showed that cell apoptosis increased in the PSMD12 knockdown, and RNA-seq indicated that the apoptosis pathway was activated, and the TXNIP, GADD45A, GADD45B, RHOB, and CDKN1A pro-apoptotic genes were highly expressed, a result that was validated by RT-qPCR and Western blot. Furthermore, restoration of PSMD12 expression decreased the expression of pro-apoptotic genes. A tumor-bearing mice assay demonstrated that BC growth was arrested by reduced PSMD12 levels in vivo. Taken together, PSMD12, a subunit of 19S regulator of 26S proteasome, was identified as a potential prognostic and therapeutic molecular target for BC, which provides a new insight for developing anticancer drugs that promote apoptosis based on the targeting of the 26S proteasome complex.

Melatonin Promotes Uterine and Placental Health: Potential Molecular Mechanisms

The development of the endometrium is a cyclic event tightly regulated by hormones and growth factors to coordinate the menstrual cycle while promoting a suitable microenvironment for embryo implantation during the “receptivity window”. Many women experience uterine failures that hamper the success of conception, such as endometrium thickness, endometriosis, luteal phase defects, endometrial polyps, adenomyosis, viral infection, and even endometrial cancer; most of these disturbances involve changes in endocrine components or cell damage. The emerging evidence has proven that circadian rhythm deregulation followed by low circulating melatonin is associated with low implantation rates and difficulties to maintain pregnancy. Given that melatonin is a circadian-regulating hormone also involved in the maintenance of uterine homeostasis through regulation of numerous pathways associated with uterine receptivity and gestation, the success of female reproduction may be dependent on the levels and activity of uterine and placental melatonin. Based on the fact that irregular production of maternal and placental melatonin is related to recurrent spontaneous abortion and maternal/fetal disturbances, melatonin replacement may offer an excellent opportunity to restore normal physiological function of the affected tissues. By alleviating oxidative damage in the placenta, melatonin favors nutrient transfer and improves vascular dynamics at the uterine–placental interface. This review focuses on the main in vivo and in vitro functions of melatonin on uterine physiological processes, such as decidualization and implantation, and also on the feto-maternal tissues, and reviews how exogenous melatonin functions from a mechanistic standpoint to preserve the organ health. New insights on the potential signaling pathways whereby melatonin resists preeclampsia and endometriosis are further emphasized in this review.

Comprehensive analysis of the differential expression profile of microRNAs in missed abortion

To screen the key circulating microRNAs (miRNAs) involved in missed abortion (MA) and explore their role in MA process. We examined the miRNA profile from the serum of three MA patients and three early pregnancy induced abortion patients (controls) by next-generation sequencing. We analyzed the target genes of the differentially expressed (DE) miRNAs to analyze the function and pathway enrichment using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, respectively. We validated five candidate miRNAs by real time-qPCR. Integrated miRNA-mRNA-pathway network analysis was performed to show the interaction network of the candidate miRNAs and their target genes of interest with the involved pathways. It was observed that 227 miRNAs were differently expressed between the MA group and the early pregnancy control group, with 58 miRNAs downregulated and 169 miRNAs upregulated in the MA group. Real-time qPCR results revealed that expression of the five candidate miRNAs, namely hsa-miR-22-3p, hsa-miR-145-3p, hsa-miR-107, hsa-miR-361-3p, and hsa-miR-378c, was consistent with the miRNA data obtained by sequencing. Integrated miRNA-mRNA-pathway network analysis illustrated that target genes of the candidate miRNAs were mainly involved in the PI3K-Akt signaling pathway, HIF-1 signaling pathway, and VEGF signaling pathway, which would have potential significance in pregnancy and MA. We are the first to reveal the DE miRNAs involved in MA and illustrate their functional interaction network. These results might provide potential circulating biomarkers and new therapeutic targets for MA.

FasL on decidual macrophages mediates trophoblast apoptosis: A potential cause of recurrent miscarriage

Macrophages can induce Fas ligand (FasL)-mediated apoptosis, and the deregulation of apoptosis is known to be associated with recurrent miscarriage (RM). The aim of the present study was to investigate the possible involvement of FasL in macrophage-mediated trophoblast apoptosis and its potential role in RM. Human decidual and placental villous tissues were collected from 81 women (21 for the RM group, 26 for the spontaneous abortion group and 34 for the control group) at 7-9 weeks of gestation. The distribution changes of macrophages and the expression of FasL on macrophages were evaluated by immunohistochemical, immunofluorescence and western blot analyses. A macrophage and trophoblast co-culture model was used to determine the effects of FasL on the apoptosis of trophoblasts. The results indicated that CD86⁺ macrophage populations in decidual tissues were significantly increased, accompanied by reduced CD163⁺ macrophages in the abortion and RM groups. Furthermore, the distribution of CD68⁺ macrophages was also significantly altered in specimens from the abortion and RM groups, and they were observed to have infiltrated into the trophoblast cells. In addition, elevated expression of FasL on CD68⁺ and CD86⁺ macrophages in the decidua was observed in the spontaneous abortion and RM groups of patients, and FasL was demonstrated to mediate the induction of trophoblast apoptosis by macrophages in co-culture. These results indicate that the aberration of macrophage-induced FasL-mediated apoptosis may represent one of the causes of RM.

RNA-sequencing analysis of umbilical cord plasma microRNAs from healthy newborns

MicroRNAs are a class of small non-coding RNA that regulate gene expression at a post-transcriptional level. MicroRNAs have been identified in various body fluids under normal conditions and their stability as well as their dysregulation in disease has led to ongoing interest in their diagnostic and prognostic potential. Circulating microRNAs may be valuable predictors of early-life complications such as birth asphyxia or neonatal seizures but there are relatively few data on microRNA content in plasma from healthy babies. Here we performed small RNA-sequencing analysis of plasma processed from umbilical cord blood in a set of healthy newborns. MicroRNA levels in umbilical cord plasma of four male and four female healthy babies, from two different centres were profiled. A total of 1,004 individual microRNAs were identified, which ranged from 426 to 659 per sample, of which 269 microRNAs were common to all eight samples. Many of these microRNAs are highly expressed and consistent with previous studies using other high throughput platforms. While overall microRNA expression did not differ between male and female cord blood plasma, we did detect differentially edited microRNAs in female plasma compared to male. Of note, and consistent with other studies of this type, adenylation and uridylation were the two most prominent forms of editing. Six microRNAs, miR-128-3p, miR-29a-3p, miR-9-5p, miR-218-5p, 204-5p and miR-132-3p were consistently both uridylated and adenylated in female cord blood plasma. These results provide a benchmark for microRNA profiling and biomarker discovery using umbilical cord plasma and can be used as comparative data for future biomarker profiles from complicated births or those with early-life developmental disorders.

FOXO3a is essential for murine endometrial decidualization through cell apoptosis during early pregnancy

Embryo implantation is essential for normal pregnancy, and the process of decidualization is critical for embryo implantation. However, the mechanism of decidualization during early pregnancy is still unknown. Forkhead box O3a (FOXO3a) is the most important functional transcription factor of the forkhead box family and is a highly conserved transcription factor of apoptosis-related genes. In the mouse uterus, FOXO3a was found to be expressed regularly from Days 1-7 of early pregnancy. Upon further exploration, it was found that FOXO3a was expressed at significantly higher levels at the implantation site than at the interimplantation site on Days 5-7 of pregnancy. Under artificial decidualization, FOXO3a was highly expressed in the first and second decidual zones. After decidualization, the expression of FOXO3a was significantly increased both in vivo and vitro. In primary stromal cells, apoptosis was reduced by decreased expression of FOXO3a after inducing decidualization. Moreover, when FOXO3a-small interfering RNA was transfected into the uteri of mice, the expression of decidualization- and apoptosis-related factors was impaired. Thus, FOXO3a might play an important role in decidualization during early pregnancy, and cell apoptosis might be one of pathways for FOXO3a-regulated decidualization.

Synergistic effects of tumor necrosis factor-α and insulin-like growth factor-I on survival of human trophoblast-derived BeWo cell line

OBJECTIVE

Trophoblast survival is regulated by cytokines and growth factors. While the pharmacological levels (10-100 ng/mL) of tumor necrosis factor (TNF)- α affect trophoblasts survival in vitro, the effects of the physiological levels (1-10 pg/mL) of TNF-α remain unknown. We investigated the effects of the physiological levels of TNF-α on proliferation and apoptosis of human trophoblast cells by using BeWo cells. Insulin-like growth factor (IGF)-I is also a potent regulator of trophoblast survival and has been known to exert synergistic effects with other hormones. The interaction of IGF-I and TNF-α on BeWo cells survival was also examined.

METHODS

After incubating BeWo under the presence of TNF-α (10-10⁵ pg/mL) and IGF-I (10² ng/mL), we assessed cell number by WST-1 assay and cell proliferation by BrdU uptake assay and immunocytochemistry with anti-Ki67 antibody. Apoptosis was evaluated by TUNEL assay and caspase-3, 8 activity assays.

RESULTS

Under the presence of IGF-I, cell number, BrdU uptake, and Ki-67 expression of BeWo were dose-dependently enhanced by low TNF-α (10-10² pg/mL), while no such effects were detected without IGF-I. Higher levels of TNF-α (10⁴-10⁵ pg/mL) showed inhibiting effects on cell number and cell proliferation. The number of TUNEL positive cells were decreased and caspase activities were suppressed by lower levels (10-10² pg/mL) of TNF-α and IGF-I independently. Higher levels of TNF-α (10⁴-10⁵ pg/mL) showed promoting effects on apoptosis irrespective of IGF-I.

CONCLUSION

The physiological levels of TNF-α and IGF-I had synergetic effects on enhancing cell proliferation and also independently inhibited apoptosis of Bewo cells.

Identification of key genes and pathways in pelvic organ prolapse based on gene expression profiling by bioinformatics analysis

PURPOSE

The aim of this study was to elucidate the molecular mechanisms and to identify the key genes and pathways for pelvic organ prolapse (POP) using bioinformatics analysis.

METHODS

The microarray data for GSE53868 included 12 POP and 12 non-POP anterior vaginal wall samples. Differentially expressed genes (DEGs) were identified by GEO2R online tool. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID database, and a DEG-associated protein-protein interaction (PPI) network was constructed using STRING and visualized in Cytoscape. MCODE was used for module analysis of the PPI network.

RESULTS

A total of 257 upregulated and 333 downregulated genes were identified. GO and KEGG pathway enrichment analyses showed that the upregulated DEGs were strongly associated with immune response, complement activation, classical pathway, phagocytosis, and recognition; the downregulated genes were mainly associated with cellular response to zinc ion, negative regulation of growth, and apoptotic process. Based on the PPI network, IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A were screened as hub genes. The four most significant sub-modules of DEGs were extracted after network module analysis. These genes were mainly associated with the negative regulation of growth and inflammatory response. The KEGG pathway enrichment analysis revealed that these genes were associated with Mineral absorption, Jak-STAT signaling pathway, cytokine-cytokine receptor interaction, and chemokine signaling pathway.

CONCLUSIONS

These microarray data and bioinformatics analyses provide a useful method for the identification of key genes and pathways associated with POP. Moreover, some crucial DEGs, such as IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A, potentially play an important role in the development and progression of POP.