PFKFB3 regulates lipopolysaccharide-induced excessive inflammation and cellular dysfunction in HTR-8/Svneo cells: Implications for the role of PFKFB3 in preeclampsia

Combined analysis of the effects of hypoxia and oxidative stress on DNA methylation and the transcriptome in HTR-8/SVneo trophoblast cells

The alterations in DNA methylation and transcriptome in trophoblast cells under conditions of low oxygen and oxidative stress have major implications for pregnancy-related disorders. However, the exact mechanism is still not fully understood. In this study, we established models of hypoxia (H group) and oxidative stress (HR group) using HTR-8/SVneo trophoblast cells and performed combined analysis of genome-wide DNA methylation changes using reduced representation bisulphite sequencing and transcriptome expression changes using RNA sequencing. Our findings revealed that the H group exhibited a higher number of differentially methylated genes and differentially expressed genes than the HR group. In the H group, only 0.90% of all differentially expressed genes displayed simultaneous changes in DNA methylation and transcriptome expression. After the threshold was expanded, this number increased to 6.29% in the HR group. Notably, both the H group and HR group exhibited concurrent alterations in DNA methylation and transcriptome expression within Axon guidance and MAPK signalling pathway. Among the top 25 differentially methylated KEGG pathways in the promoter region, 11 pathways were commonly enriched in H group and HR group, accounting for 44.00%. Among the top 25 KEGG pathways in transcriptome with significant differences between the H group and HR group, 10 pathways were consistent, accounting for 40.00%. By integrating our previous data on DNA methylation from preeclamptic placental tissues, we identified that the ANKRD37 and PFKFB3 genes may contribute to the pathogenesis of preeclampsia through DNA methylation-mediated transcriptome expression under hypoxic conditions.

Single cell RNA-sequencing reveals the cellular senescence of placental mesenchymal stem/stromal cell in preeclampsia

INTRODUCTION

Preeclampsia (PE) is a severe obstetric complication closely associated with placental dysfunction. Placental mesenchymal stem/stromal cells (PMSCs) modulate placental development while PE PMSCs are excessively senescent to disturb placental function. Nevertheless, the senescence mechanism of PE PMSCs remains unclear.

METHODS

PE-related single-cell RNA sequencing datasets (GSE173193), data of chip detection (GSE99007) and bulk transcriptome RNA sequencing datasets (GSE75010) were extracted from the GEO database. Firstly, the functional enrichment analyses of the differentially expressed genes (DEGs) in PMSCs were conducted. Then, the clusters of PE PMSCs were distinguished according to the expressions of senescence-related genes (SRGs) by consensus clustering analysis. Cell cycle analysis, senescence β-galactosidase, Transwell, and tube formation were conducted. Next, the expressions of the senescence-associated secretory phenotype (SASPs) were displayed. The characteristic genes of PE were screened by the least absolute shrinkage and selection operator analysis. CTSZ was suppressed in PMSCs and the cellular senescence levels were evaluated.

RESULTS

In this study, The DEGs in PMSCs were closely associated with cellular senescence. The score of SRGs was significantly higher and most of the SASPs were abnormally expressed in the senescent group. Seven characteristic genes of PE were identified, thereinto, CTSZ reduction may accelerate the senescence in PMSCs in vitro.

DISCUSSION

Combined with bioinformatic analysis and lab experiments, our study emphatically revealed the abnormal cellular senescence in PE PMSCs, in which CTSZ, one of the PE characteristic genes, regulated the cellular senescence levels in PMSCs. These findings might help to deepen the understanding of the senescence mechanism of PMSCs in PE.

Fructose improves titanium dioxide nanoparticles induced alterations in developmental competence of mouse oocytes

AIMS

We investigated the effects of intraperitoneal injections of titanium dioxide nanoparticles (TiO2 NPs, 100 mg/kg) for 5 consecutive days on the developmental competence of murine oocytes. Furthermore, study the effects of TiO2 NPs on antioxidant and oxidative stress biomarkers, as well as their effects on expression of apoptotic and hypoxia inducing factor-1α (HIF1A) protein translation. Moreover, the possible ameliorating effects of intraperitoneal injections of fructose (2.75 mM/ml) was examined.

MATERIALS AND METHODS

Thirty sexually mature (8-12 weeks old; ~ 25 g body weight) female mice were used for the current study. The female mice were assigned randomly to three treatment groups: Group1 (G1) mice were injected intraperitoneal (ip) with deionized water for 5 consecutive days; Group 2 (G2) mice were injected ip with TiO2 NPs (100 mg/kg BW) for 5 consecutive days; Group 3 (G3) mice were injected ip with TiO2 NPs (100 mg/kg BW + fructose (2.75 mM) for 5 consecutive days.

RESULTS

Nano-titanium significantly decreased expression of GSH, GPx, and NO, expression of MDA and TAC increased. The rates of MI, MII, GVBD and degenerated oocytes were significantly less for nano-titanium treated mice, but the rate of activated oocytes was significantly greater than those in control oocytes. TiO2 NPs significantly increased expression of apoptotic genes (BAX, Caspase 3 and P53) and HIF1A. Intraperitoneal injection of fructose (2.75 mM/kg) significantly alleviated the detrimental effects of TiO2 NPs. Transmission electron microscopy indicated that fructose mitigated adverse effects of TiO2 NPs to alter the cell surface of murine oocytes.

CONCLUSION

Results of this study suggest that the i/p infusion of fructose for consecutive 5 days enhances development of murine oocytes and decreases toxic effects of TiO2 NPs through positive effects on oxidative and antioxidant biomarkers in cumulus-oocyte complexes and effects to inhibit TiO2-induced increases in expression of apoptotic and hypoxia inducing factors.

Down-Regulation of CPEB4 Alleviates Preeclampsia through the Inhibition of Ferroptosis by PFKFB3

Gestational diabetes mellitus (GDM) complicated with preeclampsia can lead to polyhydramnios, ketosis. Herein, we explored that CPEB4 in cancer progression of preeclampsia and its underlying mechanism. All the serum samples were collected from patients with preeclampsia. These was the induction of CPEB4 in patients with preeclampsia. The serum of CPEB4 mRNA expression was positive correlation with Proteinuria, systolic blood pressure and diastolic blood pressure in patients. The serum of CPEB4 mRNA expression was also negative correlation with body weight of infant in patients. The serum of CPEB4 mRNA expression also was negative correlation with GPX4 level and GSH activity level in patients. The serum of CPEB4 mRNA expression was positive correlation with iron content in patients. CPEB4 gene inhibited trophoblast cell proliferation. CPEB4 gene promoted trophoblast cell ferroptosis by mitochondrial damage. CPEB4 gene induced PFKFB3 expression by the inhibition of PFKFB3 Ubiquitination. PFKFB3 inhibitor reduced the effects of CPEB4 on cell proliferation and ferroptosis of trophoblast cell. Taken together, the CPEB4 promoted trophoblast cell ferroptosis through mitochondrial damage by the induction of PFKFB3 expression, CPEB4 as an represents a potential therapeutic strategy for the treatment of preeclampsia or various types of GDM.

Glycolysis: A fork in the path of normal and pathological pregnancy

Glucose metabolism is vital to the survival of living organisms. Since the discovery of the Warburg effect in the 1920s, glycolysis has become a major research area in the field of metabolism. Glycolysis has been extensively studied in the field of cancer and is considered as a promising therapeutic target. However, research on the role of glycolysis in pregnancy is limited. Recent evidence suggests that blastocysts, trophoblasts, decidua, and tumors all acquire metabolic energy at specific stages in a highly similar manner. Glycolysis, carefully controlled throughout pregnancy, maintains a dynamic and coordinated state, so as to maintain the homeostasis of the maternal-fetal interface and ensure normal gestation. In the present review, we investigate metabolic remodeling and the selective propensity of the embryo and placenta for glycolysis. We then address dysregulated glycolysis that occurs in the cellular interactive network at the maternal-fetal interface in miscarriage, preeclampsia, fetal growth restriction, and gestational diabetes mellitus. We provide new insights into the field of maternal-fetal medicine from a metabolic perspective, thus revealing the mystery of human pregnancy.

Microglial Metabolic Reprogramming: Emerging Insights and Therapeutic Strategies in Neurodegenerative Diseases

Microglia, the resident immune cells of the central nervous system, play a critical role in maintaining brain homeostasis. However, in neurodegenerative conditions, microglial cells undergo metabolic reprogramming in response to pathological stimuli, including Aβ plaques, Tau tangles, and α-synuclein aggregates. This metabolic shift is characterized by a transition from oxidative phosphorylation (OXPHOS) to glycolysis, increased glucose uptake, enhanced production of lactate, lipids, and succinate, and upregulation of glycolytic enzymes. These metabolic adaptations result in altered microglial functions, such as amplified inflammatory responses and diminished phagocytic capacity, which exacerbate neurodegeneration. This review highlights recent advances in understanding the molecular mechanisms underlying microglial metabolic reprogramming in neurodegenerative diseases and discusses potential therapeutic strategies targeting microglial metabolism to mitigate neuroinflammation and promote brain health. Microglial Metabolic Reprogramming in Neurodegenerative Diseases This graphical abstract illustrates the metabolic shift in microglial cells in response to pathological stimuli and highlights potential therapeutic strategies targeting microglial metabolism for improved brain health.

Downregulation of TCL6 protected human trophoblast cells from LPS-induced inflammation and ferroptosis

Dysregulation of noncoding RNAs has been reported to have a close correlation with preeclampsia(PE)development. TCL6 was upregulated in patients with PE. In this study, we examined the impacts of TCL6 on modulating HTR-8/SVneo cells induced by LPS. LPS (100 and 200 ng/ml) was applied to induce inflammation in trophoblast cells HTR-8/SVneo. Cell viability, apoptosis, and transwell experiments were conducted. The ELISA methods were used for pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. MDA, GSH, and GPX kits were employed. Transfection was performed for expression regulation of TCL6, miR-485-5p, and TFRC in cells. Bioinformatic online tools were used to predict the targeting sites. Luciferase and RNA immunoprecipitation-qPCR were done to verify the interactions of TCL6, miR-485-5p, and TFRC. RNA expression levels were measured using RT-qPCR, and protein expression of TFRC and GPX4 was detected using a western blot. The free Fe (II) contents were measured. LPS decreased viability, invasion, and migration but enhanced apoptosis, ferroptosis, and inflammation. TCL6 expression was enhanced by LPS induction. The knockdown of TCL6 increased HTR-8/SVneo cell viability and invasion but inhibited cell apoptosis, inflammation, and ferroptosis while inhibition of miR-485-5p could reverse this through TFRC regulation. Moreover, miR-485-5p was sponged by TCL6 and bound to TFRC. TCL6 protected trophoblast cells from LPS-induced injury through the TFRC pathway.

Assessing the Immune Cell Subset and Genetic Mutations in Patients With Palindromic Rheumatism Seronegative for Rheumatoid Factor and Anti-Cyclic Citrullinated Peptide

OBJECTIVE

The etiology underlying cases of palindromic rheumatism (PR) not associated with other rheumatic diseases in patients who are seronegative for rheumatoid factor and anti-cyclic citrullinated peptide (seronegative PR) is unclear. We aimed to investigate the immune cells and genes involved.

METHODS

This was a single-center comparative study of 48 patients with seronegative PR and 48 healthy controls. Mass cytometry and RNA sequencing were used to identify distinct immune cell subsets in blood. Among the 48 seronegative PR patients, plasma samples from 40 patients were evaluated by enzyme-linked immunosorbent assay for cytokine levels, and peripheral blood samples from 25 patients were evaluated by flow cytometry for mononuclear cell subsets. Plasma samples from 21 patients were evaluated by real-time polymerase chain reaction for differential gene and protein expression, and samples from 3 patients were analyzed with whole-exome sequencing for gene mutations.

RESULTS

Immunophenotyping revealed a markedly increased frequency of CD14+CD11b+CD36+ and CD4+CD25-CD69+ cells in seronegative PR patients with active flares compared with healthy controls (P < 0.0001 for both cell subset comparisons). Gene enrichment analyses of RNA-sequencing data from sorted CD14+CD11b+CD36+ and CD4+CD25-CD69+ cells showed involvement of the inflammatory/stress response, phagocytosis, and regulation of apoptosis functional pathways. Up-regulated expression of CXCL16 and IL10RA was observed in monocytes from PR patients. Up-regulation of PFKFB3, DDIT4, and TGFB1, and down-regulation of PDIA6 were found in monocytes and lymphocytes from PR patients with active flares and PR patients in intercritical periods. Plasma levels of S100A8/A9 and interleukin-1β were elevated in PR patients. Whole-exome sequencing revealed novel polygenic mutations in HACL1, KDM5A, RASAL1, HAVCR2, PRDM9, MBOAT4, and JRKL.

CONCLUSION

In seronegative PR patients, we identified a distinct CD14+CD11b+CD36+ cell subset that can induce an inflammatory response under stress and exert antiinflammatory effects after phagocytosis of apoptotic cells, and a CD4+CD25-CD69+ T cell subset with pro- and antiinflammatory properties. Individuals with genetic mutations involving epigenetic modification, potentiation and resolution of stress-induced inflammation/apoptosis, and a dysregulated endoplasmic reticulum stress response could be predisposed to seronegative PR.

PFKFB3 knockdown attenuates Amyloid β-Induced microglial activation and retinal pigment epithelium disorders in mice

Age-related macular degeneration (AMD) is characterized by progressive accumulation of drusen deposits and retinal pigment epithelium (RPE) disorders. As the main component of drusen, amyloid β (Aβ) plays a critical role in activating microglia and causing neuroinflammation in AMD pathogenesis. However, the role of activated microglia-mediated neuroinflammation in RPE senescence remains unclear. Recent evidence indicates that inflammatory microglia are glycolytic and driven by an increase in 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), an enzyme described as the master regulator of glycolysis. In this study, we mimicked the retinal inflammatory microenvironment of AMD by intravitreal injection of oligomeric Aβ_1-40 in mice, which resulted in activation of microglia and upregulation of PFKFB3. RNA sequencing was performed to evaluate PFKFB3-mediated microglial activation. The effect of microglial activation on RPE disorders was assessed using gene knockout experiments, immunofluorescence, CCK-8 assay, and β-galactosidase staining. Intravitreal Aβ_1-40 injection induced proinflammatory activation of microglia by upregulating PFKFB3 and resulted in RPE disorders, which was verified in heterozygous Pfkfb3-deficient mice (Pfkfb3^+/-) mice, Aβ_1-40-activated microglial cell line BV2, and co-culture of RPE cell line ARPE19. RNA sequencing revealed that PFKFB3 mainly affected innate immune processes during Aβ_1-40-induced retinal inflammation. PFKFB3 knockdown inhibited RPE disorders and rescued the retinal structure and function. Overall, the modulation of PFKFB3-mediated microglial glycolysis and activation is a promising strategy for AMD treatment.

Iso-seco-tanapartholide from Artemisia argyi inhibits the PFKFB3-mediated glycolytic pathway to attenuate airway inflammation in lipopolysaccharide-induced acute lung injury mice

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese folk medicine, Artemisia argyi H.Lév. & Vaniot (A. argyi) has been used for thousands of years, and it is clinically used to treat bronchitis and asthma. However, the mechanism of action of A. argyi on respiratory tract inflammation is not clear. Accumulating evidence that phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) is actively expressed in inflammation. Here, we found that iso-seco-tanapartholide (IST), a sesquiterpene isolated from A. argyi, exhibited potent anti-inflammatory activity and significant inhibition of PFKFB3 expression. Therefore, we evaluated the effect of IST on airway inflammation and revealed its possible mechanisms.

AIM OF THE STUDY

This study aimed to investigate the protective effect and possible mechanism of IST in lipopolysaccharide (LPS)-induced acute lung injury in mice.

MATERIALS AND METHODS

In vitro, RAW264.7 cells and BMDMs were stimulated with LPS, and the level of NO and inflammatory factors TNF-α, IL-1β, and IL-6 were detected by Griess reagent and ELISA, respectively. The effect of IST on the levels of PFKFB3 and its downstream proteins (p-STAT3, p-p65) in cells was assayed by western blotting. Lactate and glycolytic phenotypes were detected by lactate kit and Seahorse assay. In vivo, a mouse model of acute lung injury was induced by LPS, and the levels of inflammatory factors were measured by ELISA. Expression of PFKFB3 and its downstream proteins (p-STAT3, p-p65) in mouse alveolar macrophages by western blotting analysis. Lung permeability assessment by Evans Blue dye assay. H&E staining and Immunocytochemistry were used to observe the protection of IST against lung injury.

RESULTS

IST significantly reduced LPS-induced expression of PFKFB3 and its downstream proteins (p-STAT3, p-p65). The inhibition of PFKFB3 has an impact on the glycolytic phenotype, such as a reduction in the rate of extracellular acidification (ECAR) and elevated lactate levels, and an increase in the rate of cellular oxygen consumption (OCR). Furthermore, IST inhibited LPS-induced NO release and increased the expression of pro-inflammatory factors TNF-α, IL-1β, and IL-6. In vivo, IST reduced pulmonary edema in LPS-induced acute lung injury, improved lung function, and reduced levels of inflammatory factors and lactate secretion.

CONCLUSIONS

These results suggest that IST improves the characteristics of ALI by inhibiting the expression of the PFKFB3-mediated glycolytic pathway and may be a potential anti-inflammatory agent for inflammation-related lung diseases.

PVT1/miR-145-5p/HK2 modulates vascular smooth muscle cells phenotype switch via glycolysis: The new perspective on the spiral artery remodeling

INTRODUCTION

Vascular smooth muscle cells (VSMC) switched from a contractile phenotype to a synthetic phenotype during the decidual spiral artery (SPAs) remodeling process. The lncRNA plasmacytoma variant translocation 1 (PVT1) and glucose metabolism have been found to regulate the VSMC phenotype switch. This study aimed to analyze the dynamic expression of PVT1 and glycolytic key enzymes hexokinase2 (HK2) at different remodeling stages in early human pregnancy and elucidate the underlying mechanism of the PVT1/miR-145-5p/HK2 axis involved in the spiral artery remodeling.

METHODS

qRT-PCR, Western blot (WB) analysis, Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were used to detect the expression and localization of PVT1 and HK2 in decidual tissue. HA-VSMCs were transfected with specific siRNA, shRNA and plasmids to regulate corresponding genes. Extracellular lactate, cellular ATP, ROS, and intracellular NADPH levels were measured using the corresponding assay kits. Migration was measured by wound-healing and Transwell assays. Contractile phenotypic markers α-SMA, MYH11 with calponin and synthetic phenotypic markers OPN and vimentin were detected by WB. The PDC model was used to detect the degree of spiral arterial remodeling.

RESULTS

PVT1 and HK2 were upregulated with gestational age (GA) increasing in decidual tissue during the early pregnancy. HK2 regulated the glycolytic activity and VSMC phenotype switch in vitro. PVT1 regulated the glycolytic activity and VSMC phenotype switch through HK2. PVT1 played a ceRNA role in regulating HK2 expression by sponging miR-145-5p. PVT1 and HK2 influenced spiral artery remodeling in the PDC model.

DISCUSSION

PVT1 and HK2 were upregulated, and miR-145-5p was downregulated in decidua with the GA increasing. Meanwhile, the PVT1/miR-145-5p/HK2 axis may be involved in regulating the phenotypic switch and migratory capacity of VSMCs by affecting glycolysis in decidual SPAs remodeling.

PFKFB3-mediated glycometabolism reprogramming modulates endothelial differentiation and angiogenic capacity of placenta-derived mesenchymal stem cells

BACKGROUND

Mesenchymal stem cells (MSCs) have a great potential ability for endothelial differentiation, contributing to an effective means of therapeutic angiogenesis. Placenta-derived mesenchymal stem cells (PMSCs) have gradually attracted attention, while the endothelial differentiation has not been fully evaluated in PMSCs. Metabolism homeostasis plays an important role in stem cell differentiation, but less is known about the glycometabolic reprogramming during the PMSCs endothelial differentiation. Hence, it is critical to investigate the potential role of glycometabolism reprogramming in mediating PMSCs endothelial differentiation.

METHODS

Dil-Ac-LDL uptake assay, flow cytometry, and immunofluorescence were all to verify the endothelial differentiation in PMSCs. Seahorse XF Extracellular Flux Analyzers, Mito-tracker red staining, Mitochondrial membrane potential (MMP), lactate secretion assay, and transcriptome approach were to assess the variation of mitochondrial respiration and glycolysis during the PMSCs endothelial differentiation. Glycolysis enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) was considered a potential modulator for endothelial differentiation in PMSCs by small interfering RNA. Furthermore, transwell, in vitro Matrigel tube formation, and in vivo Matrigel plug assays were performed to evaluate the effect of PFKFB3-induced glycolysis on angiogenic capacities in this process.

RESULTS

PMSCs possessed the superior potential of endothelial differentiation, in which the glycometabolic preference for glycolysis was confirmed. Moreover, PFKFB3-induced glycometabolism reprogramming could modulate the endothelial differentiation and angiogenic abilities of PMSCs.

CONCLUSIONS

Our results revealed that PFKFB3-mediated glycolysis is important for endothelial differentiation and angiogenesis in PMSCs. Our understanding of cellular glycometabolism and its regulatory effects on endothelial differentiation may propose and improve PMSCs as a putative strategy for clinical therapeutic angiogenesis.

The Gut Microbiota Dysbiosis in Preeclampsia Contributed to Trophoblast Cell Proliferation, Invasion, and Migration via lncRNA BC030099/NF-κB Pathway

Background

Preeclampsia (PE) is the main reason of maternal and perinatal morbidity and mortality. Gut microbiota imbalance in PE patients is accompanied by elevated serum lipopolysaccharide (LPS) levels, but whether it affects the occurrence and development of PE, the underlying mechanism is not clear. This paper intends to investigate the relationship between lncRNA BC030099, inflammation, and gut microbiota in PE.

Methods

The feces of the patients were collected, and gut microbiota changes were assessed by 16S rRNA sequencing and pathway analysis by PICRUSt. Next, we examined LPS and lncRNA BC030099 levels in feces or placenta of PE patients. Then, we knocked down lncRNA BC030099 in HTR-8/SVneo cells and added the NF-κB pathway inhibitor JSH-23. CCK-8 and Transwell assays were performed to determine cell proliferation, migration, and invasion. Western blot was utilized to evaluate MMP2, MMP9, snail, and E-cadherin, p-IκBα, IκBα, and nuclear NF-κB p65 levels. IL-6, IL-1β, and TNF-α levels were examined by ELISA.

Results

Gut microbiota was altered in PE patients, and microbial genes associated with LPS biosynthesis were significantly elevated in gut microbiota in the PE group. LPS level in feces and placenta of PE group was significantly elevated. lncRNA BC030099 level in placenta of PE group was also notably promoted. Knockdown of lncRNA BC030099 promoted HTR-8/SVneo cell proliferation, migration, and invasion. Knockdown of lncRNA BC030099 also elevated MMP2, MMP9, and snail levels and repressed E-cadherin level. In addition, lncRNA BC030099 affected NF-κB pathway. Furthermore, NF-κB inhibitor reversed HTR-8/SVneo cell proliferation, invasion, and migration induced by LPS.

Conclusions

The gut microbiota dysbiosis in PE contributed to HTR-8/SVneo cell proliferation, invasion, and migration via lncRNA BC030099/NF-κB pathway.

Significance of Placental Mesenchymal Stem Cell in Placenta Development and Implications for Preeclampsia

The well-developed placentation is fundamental for the reproductive pregnancy while the defective placental development is the pathogenetic basis of preeclampsia (PE), a dangerous complication of pregnancy comprising the leading causes of maternal and perinatal morbidity and mortality. Placenta-derived mesenchymal stem cells (PMSCs) are a group of multipotent stem cells that own a potent capacity of differentiating into constitutive cells of vessel walls. Additionally, with the paracrine secretion of various factors, PMSCs inextricably link and interact with other component cells in the placenta, collectively improving the placental vasculature, uterine spiral artery remolding, and uteroplacental interface immunoregulation. Recent studies have further indicated that preeclamptic PMSCs, closely implicated in the abnormal crosstalk between other ambient cells, disturb the homeostasis and development in the placenta. Nevertheless, PMSCs transplantation or PMSCs exosome therapies tend to improve the placental vascular network and trophoblastic functions in the PE model, suggesting PMSCs may be a novel and putative therapeutic strategy for PE. Herein, we provide an overview of the multifaceted contributions of PMSCs in early placental development. Thereinto, the intensive interactions between PMSCs and other component cells in the placenta were particularly highlighted and further extended to the implications in the pathogenesis and therapeutic strategies of PE.

Metformin Corrects Glucose Metabolism Reprogramming and NLRP3 Inflammasome-Induced Pyroptosis via Inhibiting the TLR4/NF-κB/PFKFB3 Signaling in Trophoblasts: Implication for a Potential Therapy of Preeclampsia

NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome-mediated pyroptosis is a crucial event in the preeclamptic pathogenesis, tightly linked with the uteroplacental TLR4/NF-κB signaling. Trophoblastic glycometabolism reprogramming has now been noticed in the preeclampsia pathogenesis, plausibly modulated by the TLR4/NF-κB signaling as well. Intriguingly, cellular pyroptosis and metabolic phenotypes may be inextricably linked and interacted. Metformin (MET), a widely accepted NF-κB signaling inhibitor, may have therapeutic potential in preeclampsia while the underlying mechanisms remain unclear. Herein, we investigated the role of MET on trophoblastic pyroptosis and its relevant metabolism reprogramming. The safety of pharmacologic MET concentration to trophoblasts was verified at first, which had no adverse effects on trophoblastic viability. Pharmacological MET concentration suppressed NLRP3 inflammasome-induced pyroptosis partly through inhibiting the TLR4/NF-κB signaling in preeclamptic trophoblast models induced via low-dose lipopolysaccharide. Besides, MET corrected the glycometabolic reprogramming and oxidative stress partly via suppressing the TLR4/NF-κB signaling and blocking transcription factor NF-κB1 binding on the promoter PFKFB3, a potent glycolytic accelerator. Furthermore, PFKFB3 can also enhance the NF-κB signaling, reduce NLRP3 ubiquitination, and aggravate pyroptosis. However, MET suppressed pyroptosis partly via inhibiting PFKFB3 as well. These results provided that the TLR4/NF-κB/PFKFB3 pathway may be a novel link between metabolism reprogramming and NLRP3 inflammasome-induced pyroptosis in trophoblasts. Further, MET alleviates the NLRP3 inflammasome-induced pyroptosis, which partly relies on the regulation of TLR4/NF-κB/PFKFB3-dependent glycometabolism reprogramming and redox disorders. Hence, our results provide novel insights into the pathogenesis of preeclampsia and propose MET as a potential therapy.

HMGB1 regulates lipopolysaccharide-induced cellular dysfunction in HTR8/SVneo cells: Implications for the role of HMGB1 in unexplained spontaneous miscarriage

INTRODUCTION

Approximately half of miscarriages are of an unknown aetiology and are likely characterized by aberrant inflammation at the uteroplacental interface. High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that participates in the pathological inflammatory response. The present study investigated the role of HMGB1 in inflammation-induced damage in trophoblasts and elucidated the underlying mechanism.

METHODS

Immunohistochemistry, qRT-PCR and Western blotting were used to detect the expression of HMGB1 in early unexplained miscarriage and normal placentas. Lipopolysaccharide (LPS)-induced HTR8/SVneo cells were used as an in vitro model to mimic the aberrant inflammation at the uteroplacental interface of miscarriage. The expression of HMGB1 and the autophagy-related proteins LC3 and Beclin1 was detected using Western blotting. Autophagy was studied in villous tissues using immunofluorescence and Western blotting. Cell proliferation and migration were analysed.

RESULTS

The expression level of HMGB1 in villous tissues with early unexplained miscarriage was significantly higher than the normal pregnancy group. The inhibition of HMGB1 in LPS-treated HTR8/SVneo cells decreased the expression of Beclin 1 and LC3, which promoted cell proliferation and migration. We found a high level of autophagy in miscarriage placentas. HMGB1 and autophagy inhibition reversed the proliferation and migration of LPS-induced HTR-8/SVneo cells.

DISCUSSION

Our results demonstrated that HMGB1 participated in LPS-induced inflammation via autophagy and regulated trophoblast functions, such as cell proliferation and migration, to potentially participate in the pathogenesis of miscarriage.