Physiological and pathological regulation of autophagy in pregnancy

Hydroxychloroquine improves pregnancy outcomes by inhibiting excessive autophagy in extravillous trophoblast caused by an anti-phospholipid syndrome

OBJECTIVES

This study aims to investigate the mechanism of hydroxychloroquine (HCQ) immunoregulation therapy in improving adverse pregnancy outcomes of recurrent miscarriages (RM) caused by antiphospholipid syndrome (APS).

METHODS

(i) Immunofluorescence staining was used to analyse the potential targets of antiphospholipid antibodies at the maternal-fetal interface in normal early pregnancy; (ii) Immunohistochemical and immunofluorescence techniques were used to compare and analyse the placenta vascular remodeling, villus tissue synthetic secretion function, trophoblastic autophagy and apoptosis levels in first trimester decidual tissue between normal and APS caused recurrent miscarriages (APS-RM) cases; (iii) HTR8/SVneo and BeWo cell lines were treated with serum from normal and APS-RM cases, and quantified by RT-PCR and Western blot to analysis the expression levels of cell invasion, secretion, autophagy and apoptosis-related molecules; (iv) After adding 0.1 μg/ml HCQ to the serum-treated cell line, the expression of autophagy and invasion-related proteins were detected, and invasion and tube formation of HTR8/SVneo cells was assessed by transwell experiments and tube formation assay.

RESULTS

(i)β2-glycoprotein Ⅰ antigen is expressed in all types of trophoblasts at the maternal-fetal interface in first trimester; (ii) The extravillous trophoblast cells (EVTs) have excessive autophagy in the decidual tissue of the APS-RM cases, and the uterine spiral artery was remodelled insufficiently; (iii) APS-RM cases serum can lead to cell excessive autophagy, and decrease cell invasion and tube formation in vitro; (iv) 0.1 μg/ml HCQ could rescue abnormal cell status caused by APS cases serum in HTR8/SVneo cells in vitro; (v) APS cases serum mainly affects the invasion and tube formation of EVTs, but has little effect on the function of villous trophoblast cells.

CONCLUSIONS

Antiphospholipid antibodies can lead to excessive autophagy in EVTs, thereby affecting ability of invasion and remodeling of spiral arteries, which is one of the mechanisms leading to adverse pregnancy outcomes. HCQ can rescue adverse pregnancy outcomes in APS patients by inhibiting excessive autophagy.

Effects of SARS-COV-2 on molecules involved in vascularization and autophagy in placenta tissues

SARS-CoV-2 infection is considered as a multi-organ disease, and several studies highlighted the relevance of the virus infection in the induction of vascular injury and tissue morphological alterations, including placenta. In this study, immunohistochemical analyses were carried out on placenta samples derived from women with COVID-19 infection at delivery (SARS-CoV-2 PCR+) or women healed from a COVID-19 infection (SARS-CoV-2 negative at delivery, SARS-CoV-2 PCR-) or women who gave birth before 2019 (Control). Angiotensin Converting Enzyme 2 (ACE2) receptor, Cluster of differentiation 147 (CD147), endothelial CD34 marker, Vascular Endothelial Growth Factor (VEGF) and total Microtubule-associated protein 1 Light Chain 3B marker (LC3B) were investigated in parallel with SPIKE protein by standard IHC. Multiplexed Immunohistochemical Consecutive Staining on Single Slide (MICSSS) was used to examine antigen co-expression in the same specimen. SPIKE protein was detected in villi and decidua from women with ongoing infection, with no significant differences in SPIKE staining between both biopsy sites. VEGF was significantly increased in SARS-CoV-2 PCR + biopsies compared to control and SARS-CoV-2 PCR- samples, and MICSSS method showed the co-localization of SPIKE with VEGF and CD34. The induction of autophagy, as suggested by the LC3B increase in SARS-CoV-2 PCR + biopsies and the co-expression of LC3B with SPIKE protein, may explain one of the different mechanisms by which placenta may react to infection. These data could provide important information on the impact that SARS-CoV-2 may have on the placenta and mother-to-fetus transmission.

Changes in cytokine and sequestosome-1 levels during twin pregnancy progression: Association with outcome

BACKGROUND

Twin pregnancies are associated with complications and adverse outcomes. The number of twin pregnancies has increased in the last decades, due to the use of assisted reproductive techniques and delayed childbearing. Analysis of changes that occur during twin pregnancy progression and their association with outcome will lead to improved clinical interventions.

OBJECTIVE

We evaluated if the plasma concentration of select cytokines and the level of sequestosome-1 (p62) in peripheral blood mononuclear cells (PBMCs) during each trimester of twin gestations was predictive of pregnancy outcome.

STUDY DESIGN

This prospective, observational study was conducted at Careggi University Hospital, Florence, Italy. Plasma from 82 women with twin pregnancies was collected in each trimester for measurement of interleukin (IL)-1β, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α. The intracellular PBMC concentration of p62, a protein involved in autophagy, kinase activity and cell differentiation, was also determined.

RESULTS

IL-1β (p < 0.001), IL-6 (p < 0.001), TNF-α (p < 0.001) and p62 (p < 0.05) increased from the 1st to the 2nd to the 3rd trimester. The TNF-α level was correlated with the IL-1β concentration in the 1st and 3rd trimesters p < 0.01) and with the IL-6 concentration in each of the three trimesters (p < 0.01). The intracellular p62 level in PBMCs was negatively correlated with the concentration of IL-1β in the 2nd trimester (p < 0.05) and negatively correlated with the IL-6 level in the 3rd trimester (p < 0.05). The TNF-α level was significantly higher in the 2nd (p < 0.05) and 3rd (p < 0.001) trimester in women with a spontaneous preterm delivery. The TNF-α concentrations in the 2nd (p < 0.05) and 3rd (p < 0.01) trimester, respectively, and 3rd trimester IL-6 (p < 0.01), were negatively associated with gestational age at delivery. The concentration of IL-6 was highest in the 2nd (p < 0.05) and 3rd (p < 0.05) trimesters in women who utilized assisted reproductive technologies. An elevated IL-1β level in the 3rd trimester was associated with gestational diabetes mellitus (p < 0.05).

CONCLUSION

Variations in cytokine levels between individual women during the three trimesters of twin gestations are predictive of spontaneous preterm delivery and the onset of gestational diabetes.

The crosstalk between cell death and pregnancy related diseases: A narrative review

Programmed cell death is intricately linked to various physiological phenomena such as growth, development, and metabolism, as well as the proper function of the pancreatic β cell and the migration and invasion of trophoblast cells in the placenta during pregnancy. Traditional and recently identified programmed cell death include apoptosis, autophagy, pyroptosis, necroptosis, and ferroptosis. In addition to cancer and degenerative diseases, abnormal activation of cell death has also been implicated in pregnancy related diseases like preeclampsia, gestational diabetes mellitus, intrahepatic cholestasis of pregnancy, fetal growth restriction, and recurrent miscarriage. Excessive or insufficient cell death and pregnancy related diseases may be mutually determined, ultimately resulting in adverse pregnancy outcomes. In this review, we systematically describe the characteristics and mechanisms underlying several types of cell death and their roles in pregnancy related diseases. Moreover, we discuss potential therapeutic strategies that target cell death signaling pathways for pregnancy related diseases, hoping that more meaningful treatments will be applied in clinical practice in the future.

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

When autophagy meets placenta development and pregnancy complications

Autophagy is a common biological phenomenon in eukaryotes that has evolved and reshaped to maintain cellular homeostasis. Under the pressure of starvation, hypoxia, and immune damage, autophagy provides energy and nutrients to cells, which benefits cell survival. In mammals, autophagy is an early embryonic nutrient supply system involved in early embryonic development, implantation, and pregnancy maintenance. Recent studies have found that autophagy imbalance in placental tissue plays a key role in the occurrence and development of pregnancy complications, such as gestational hypertension, gestational obesity, premature birth, miscarriage, and intrauterine growth restriction. This mini-review summarizes the molecular mechanism of autophagy regulation, the autophagy pathways, and related factors involved in placental tissue and comprehensively describes the role of autophagy in pregnancy complications.

Protective role of stem cells in POI: Current status and mechanism of action, a review article

Premature ovarian insufficiency (POI) has far-reaching consequences on women's life quality. Due to the lack of full recognition of the etiology and complexity of this disease, there is no appropriate treatment for infected patients. Recently, stem cell therapy has attracted the attention of regenerative medicine scholars and offered promising outcomes for POI patients. Several kinds of stem cells, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) have been used for the treatment of ovarian diseases. However, their potential protective mechanisms are still unknown. Undoubtedly, a better understanding of the therapeutic molecular and cellular mechanisms of stem cells will address uncover strategies to increase their clinical application for multiple disorders such as POI. This paper describes a detailed account of the potential properties of different types of stem cells and provides a comprehensive review of their protective mechanisms, particularly MSC, in POI disorder. In addition, ongoing challenges and several strategies to improve the efficacy of MSC in clinical use are addressed. Therefore, this review will provide proof-of-concept for further clinical application of stem cells in POI.

Autophagy-mediated immune system regulation in reproductive system and pregnancy-associated complications

Autophagy lysosomal degradation is the main cell mechanism in cellular, tissue and organismal homeostasis and is controlled by autophagy-related genes (ATG). Autophagy has important effects in cellular physiology, including adaptation to metabolic stress, removal of dangerous cargo (such as protein aggregates, damaged organelles, and intracellular pathogens), regeneration during differentiation and development, and prevention of genomic damage in general. Also, it has been found that autophagy is essential for pre-implantation, development, and maintaining embryo survival in mammals. Under certain conditions, autophagy may be detrimental through pro-survival effects such as cancer progression or through possible cell death-promoting effects. Hormonal changes and environmental stress can initiate autophagy in reproductive physiology. The activity of autophagy can be upregulated under conditions like a lack of nutrients, inflammation, hypoxia, and infections. In this regard the dysregulation of autophagy involved in some pregnancy complications such as preeclampsia (PE) and pregnancy loss, and has a major impact on reproductive outcomes. Therefore, we aimed to discuss the relationship between autophagy and the female reproductive system, with a special focus on the immune system, and its role in fetal and maternal health.

Activation of Atg5-dependent placental lipophagy ameliorates cadmium-induced fetal growth restriction

Cadmium (Cd), an environmental contaminant, can result in placental non-selective autophagy activation and fetal growth restriction (FGR). However, the role of placental lipophagy, a selective autophagy, in Cd-induced FGR is unclear. This work uses case-control study, animal experiments and cultures of primary human placental trophoblast cells to explore the role of placental lipophagy in Cd-induced FGR. We found association of placental lipophagy and all-cause FGR. Meanwhile, pregnancy Cd exposure induced FGR and placental lipophgay. Inhibition of placental lipophagy by pharmacological and genetic means (Atg5^-/- mice) exacerbated Cd-caused FGR. Inversely, activating of placental lipophagy relieved Cd-stimulated FGR. Subsequently, we found that activation of Atg5-dependent lipophagy degrades lipid droplets to produce free cholesterol, and promotes placental progesterone (P4) synthesis. Gestational P4 supplementation significantly reversed Cd-induced FGR. Altogether, activation of Atg5-dependent placental lipophagy ameliorates Cd-induced FGR.

Recent insight into autophagy and immunity at the maternal-fetal interface

Autophagy is a lysosomal degradation pathway that supports metabolic adaptation and energy cycling. It is essential for cell homeostasis, differentiation, development, and survival. Recent studies have shown that autophagy could influence immune responses by regulating immune cell functions. Reciprocally, immune cells strongly influence autophagy. Immune cells at the maternal-fetal interface are thought to play essential roles in pregnancy. Here, we review the induction of autophagy at the maternal-fetal interface and its role in decidualization and placental development. Additionally, we emphasize the role of autophagy in the immune microenvironment at the maternal-fetal interface, including innate immunity, adaptive immunity, and immune tolerance molecules. It also suggests new research directions and prospects.

Down-regulation of autophagy proteins is associated with higher mTOR expression in the placenta of pregnant women with preeclampsia

Autophagy is a lysosomal degradation pathway that removes protein aggregates and damaged organelles maintaining cellular integrity. It seems to be essential for cell survival during stress, starvation, hypoxia, and consequently to the placenta implantation and development. Preeclampsia (PE) is a multisystemic disorder characterized by the onset of hypertension associated or not with proteinuria and other maternal complications. Considering that the placenta seems to play an important role in the pathogenesis of PE, the objective of the present study was to evaluate protein levels of light chain protein (LC3), beclin-1, and the mammalian target of rapamycin (mTOR) in the placenta of pregnant women with PE. Placental tissues collected from 20 women with PE and 20 normotensive (NT) pregnant women were evaluated for LC3, beclin-1, and mTOR expression by qPCR and immunohistochemistry. The mRNA for LC3 and beclin-1 were significantly lower, while mTOR gene expression was significantly higher in the placenta of pregnant women with PE than in the NT group. Placentas of PE women showed significantly decreased protein expression of LC3-II and beclin-1, whereas mTOR was significantly increased compared with the NT pregnant women. There was a negative correlation between protein expression of mTOR and LC3-II in the placental tissue of PE women. In conclusion, the results showed autophagy deficiency suggesting that failure in this degradation process may contribute to the pathogenesis of PE; however, new studies involving cross-talk between autophagy and inflammatory molecular mechanisms might help to better understand the autophagy process in this obstetric pathology.

Placenta autophagy is closely associated with preeclampsia

The pathogenesis of preeclampsia (PE) is complex and placental internal homeostasis is regulated by cellular autophagy. However, there are fewer studies related to the role of placental autophagy in the pathogenesis of PE. The GSE75010 and GSE10588 datasets were downloaded from the gene expression omnibus (GEO) database. In the GSE75010 (test cohort), 103 differentially expressed genes (DEGs) were screened using "Limma" package, and 281 PE characteristic genes were screened by weighted gene coexpression network analysis (WGCNA). Combined with the autophagy gene set, a total of 5 autophagy-related hub genes were obtained. Three biomarkers (HK2, PLOD2, and TREM1) were then further screened by random forest(RF) model and least absolute shrinkage and selection operator(LASSO) algorithm as diagnostic of PE. In the unsupervised consensus clustering analysis, HK2, PLOD2, and TREM1 may be synergistically involved in hypoxia-induced autophagy and hypoxia-inducible factor 1(HIF-1) signaling pathway to induce PE. In addition, we constructed and evaluated a nomogram model for PE diagnosis using these three key diagnostic biomarkers, and the results showed that the model had significantly excellent predictive power (AUC values of GSE75010 and GSE10588 datasets were 0.869 and 0.876, respectively). In terms of immune infiltration, a higher proportion of T cells CD8, and a lower proportion of Macrophages M2 were found in PE placentas compared to normal tissue, and high expression of HK2, PLOD2, and TREM1 were accompanied by low levels of Macrophages M2 infiltration. HK2, PLOD2, and TREM1 may be associated with the development of pre-eclampsia, and their mechanisms of action in preeclampsia need to be further investigated.

Comprehensive Analysis of Quantitative Proteomics With DIA Mass Spectrometry and ceRNA Network in Intrahepatic Cholestasis of Pregnancy

Background: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific complication characterized by pruritus without skin damage and jaundice. The poor perinatal outcomes include fetal distress, preterm birth, and unexpected intrauterine death. However, the mechanism of ICP leading to poor prognosis is still unclear.

Methods: We analyzed 10 ICP and 10 normal placental specimens through quantitative proteomics of data-independent acquisition (DIA) to screen and identify differentially expressed proteins. GO, KEGG, COG/KOG, StringDB, InterProScan, Metascape, BioGPS, and NetworkAnalyst databases were used in this study. PITA, miRanda, TargetScan, starBase, and LncBase Predicted v.2 were used for constructing a competing endogenous RNA (ceRNA) network. Cytoscape was used for drawing regulatory networks, and cytoHubba was used for screening core nodes. The ICP rat models were used to validate the pathological mechanism.

Results: GO, KEGG, and COG/KOG functional enrichment analysis results showed the differentially expressed proteins participated in autophagy, autophagosome formation, cofactor binding, JAK-STAT signaling pathway, and coenzyme transport and metabolism. DisGeNET analysis showed that these differentially expressed proteins were associated with red blood cell disorder and slow progression. We further analyzed first 12 proteins in the upregulated and downregulated differentially expressed proteins and incorporated clinicopathologic parameters. Our results showed HBG1, SPI1, HBG2, HBE1, FOXK1, KRT72, SLC13A3, MBD2, SP9, GPLD1, MYH7, and BLOC1S1 were associated with ICP development. ceRNA network analysis showed that MBD2, SPI1, FOXK1, and SLC13A3 were regulated by multiple miRNAs and lncRNAs.

Conclusion: ICP was associated with autophagy. The ceRNA network of MBD2, SPI1, FOXK1, and SLC13A3 was involved in ICP progression, and these core proteins might be potential target.

Impaired placental mitophagy and oxidative stress are associated with dysregulated BNIP3 in preeclampsia

Preeclampsia (PE) is a severe multisystem pregnancy complication characterized by gestational hypertension and proteinuria. Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3) is a mediator of mitophagy and has been proven to be associated with PE, but the mechanism is not well understood. This study aimed to investigate the role of BNIP3 in PE. Placentae from preeclamptic and normal pregnancies were analyzed by western-blot and transmission electron microscopy to quantify the level of BNIP3 expression and observe the organelle morphologies. Trophoblast cells with knockdown BNIP3 were analyzed by western-blot, immunofluorescence, flow cytometry, migration and invasion assays. BNIP3 expression was suppressed in PE patients. Impaired autophagy and increased mitochondrial damage were observed in PE placentae when compared with normal placentae. Suppression of BNIP3 inhibited Beclin-1 expression and reduced the transformation of LC3-I to LC3-II. In the knockdown BNIP3 group, p62 was overexpressed, ROS accumulated and the apoptotic process was elevated under oxidative stress condition. The knockdown of BNIP3 reduced the colocalization of GFP-LC3 and mitochondria. The findings of this study suggest that dysregulated BNIP3 is associated with impaired mitophagy, oxidative stress, and apoptosis in PE. The study provides new insights into the role of BNIP3 in the pathophysiology of PE.

FPR2 serves a role in recurrent spontaneous abortion by regulating trophoblast function via the PI3K/AKT signaling pathway

Recurrent spontaneous abortion (RSA) effects both the physical and mental health of women of reproductive age. Trophoblast dysfunction may result in RSA due to shallow placental implantation. The mechanisms underlying formyl peptide receptor 2 (FPR2) on the biological functions of trophoblasts remain to be elucidated. The present study aimed to explore the potential functions of FPR2, a G protein‑coupled receptor, in placental trophoblasts. The location and expression levels of FPR2 in the villi tissue of patients with RSA were detected using immunohistochemical staining, reverse transcription‑quantitative PCR and western blotting. Following the transfection of small interfering RNA targeting FPR2 in HTR‑8/SVneo cells, a Cell Counting Kit‑8 assay was used to determine the levels of cell viability. Flow cytometry was used to examine the levels of cell apoptosis and gap closure and Transwell assays were carried out to evaluate the levels of cell migration and invasion. A tube formation assay was performed to detect the levels of capillary‑like structure formation. Western blotting was used to detect the expression levels of proteins in the associated signaling pathways. The expression of FPR2 was present in villi trophoblasts and was markedly increased in patients with RSA. The levels of trophoblast invasion, migration and tube formation were markedly increased following FPR2 knockdown, whereas the levels of apoptosis were markedly decreased. In addition, FPR2 knockdown caused an increase in the phosphorylation levels of AKT and PI3K. Thus, FPR2 may be involved in the regulation of trophoblast function via the PI3K/AKT signaling pathway. The results of the present study provided a theoretical basis for the use of FPR2 as a target for the treatment of trophoblast‑associated diseases, such as RSA.

Current understanding of autophagy in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease during pregnancy. Manifested with pruritus and elevation in bile acids, the etiology of ICP is still poorly understood. Although ICP is considered relatively benign for the mother, increased rates of adverse fetal outcomes including sudden fetal demise are possible devastating outcomes associated with ICP. Limited understanding of the underlying mechanisms restricted treatment options and managements of ICP. In recent decades, evolving evidence indicated the significance of autophagy in pregnancy and pregnancy complications. Autophagy is an ancient self-defense mechanism which is essential for cell survival, differentiation and development. Autophagy has pivotal roles in embryogenesis, implantation, and maintenance of pregnancy, and is involved in the orchestration of diverse physiological and pathological cellular responses in patients with pregnancy complications. Recent advances in these research fields provide tantalizing targets on autophagy to improve the care of pregnant women. This review summarizes recent advances in understanding autophagy in ICP and its possible roles in the causation and prevention of ICP.

Cannabidiol disrupts apoptosis, autophagy and invasion processes of placental trophoblasts

Cannabidiol (CBD) is a constituent of Cannabis sativa without psychotropic activity, whose medical benefits have been recognised. However, little is known about the potential toxic effects of CBD on reproductive health. Placental development involves tightly controlled processes of cell proliferation, differentiation, apoptosis, autophagy and migration/invasion of trophoblast cells. Cannabis use by pregnant women has been increasing, mainly for the relief of nausea associated with the first trimester, which raises great concern. Regarding the crucial role of cytotrophoblast cells (CTs) and extravillous trophoblasts (EVTs) in placentation, the effects of CBD (1-10 µM) were studied, using in vitro model systems BeWo and HTR-8/SVneo cell lines, respectively. CBD causes cell viability loss in a dose-dependent manner, disrupts cell cycle progression and induces apoptosis through the mitochondrial pathway, on both cell models. Moreover, CBD induces autophagy only in HTR-8/SVneo cells, being this process a promoter of apoptosis. Hypoxia-responsive genes HIF1A and SPP1 were also increased in CBD-treated HTR-8/SVneo cells suggesting a role for HIF-1α in the apoptotic and autophagic processes. In addition, CBD was able to decrease HTR-8/SVneo cell migration. Therefore, CBD interferes with trophoblast turnover and placental remodelling, which can have a considerable impact on pregnancy outcome. Thus, from an in vitro perspective our study adds new evidence for the potential negative impact of cannabis use by pregnant women.

Placental Antioxidant Defenses and Autophagy-Related Genes in Maternal Obesity and Gestational Diabetes Mellitus

Maternal obesity and gestational diabetes mellitus (GDM) are increasing worldwide, representing risk factors for both mother and child short/long-term outcomes. Oxidative stress, lipotoxicity and altered autophagy have already been reported in obesity, but few studies have focused on obese pregnant women with GDM. Antioxidant and macro/chaperone-mediated autophagy (CMA)-related gene expressions were evaluated herein in obese and GDM placentas. A total of 47 women with singleton pregnancies delivered by elective cesarean section were enrolled: 16 normal weight (NW), 18 obese with no comorbidities (OB GDM(–)), 13 obese with GDM (OB GDM(+)). Placental gene expression was assessed by real-time PCR. Antioxidant gene expression (CAT, GPX1, GSS) decreased, the pro-autophagic ULK1 gene increased and the chaperone-mediated autophagy regulator PHLPP1 decreased in OB GDM(–) vs. NW. On the other hand, PHLPP1 expression increased in OB GDM(+) vs. OB GDM(–). When analyzing results in relation to fetal sex, we found sexual dimorphism for both antioxidant and CMA-related gene expressions. These preliminary results can pave the way for further analyses aimed at elucidating the placental autophagy role in metabolic pregnancy disorders and its potential targetability for the treatment of diabetes outcomes.