A role for cellular senescence in birth timing

Association of Paternal Age Alone and Combined with Maternal Age with Perinatal Outcomes: A Prospective Multicenter Cohort Study in China

Maternal and paternal age at birth is increasing globally. Maternal age may affect perinatal outcomes, but the effect of paternal age and its joint effect with maternal age are not well established. This prospective, multicenter, cohort analysis used data from the University Hospital Advanced Age Pregnant Cohort Study in China from 2016 to 2021, to investigate the separate association of paternal age and joint association of paternal and maternal age with adverse perinatal outcomes. Of 16,114 singleton deliveries, mean paternal and maternal age (± SD) was 38.0 ± 5.3 years and 36.0 ± 4.1 years. In unadjusted analyses, older paternal age was associated with increased risks of gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy, preeclampsia, placenta accreta spectrum disorders, placenta previa, cesarean delivery (CD), and postpartum hemorrhage, preterm birth (PTB), large-for-gestational-age, macrosomia, and congenital anomaly, except for small-for-gestational-age. In multivariable analyses, the associations turned to null for most outcomes, and attenuated but still significant for GDM, CD, PTB, and macrosomia. As compare to paternal age of < 30 years, the risks in older paternal age groups increased by 31-45% for GDM, 17-33% for CD, 32-36% for PTB, and 28-31% for macrosomia. The predicted probabilities of GDM, placenta previa, and CD increased rapidly with paternal age up to thresholds of 36.4-40.3 years, and then plateaued or decelerated. The risks of GDM, CD, and PTB were much greater for pregnancies with younger paternal and older maternal age, despite no statistical interaction between the associations related to paternal and maternal age. Our findings support the advocation that paternal age, besides maternal age, should be considered during preconception counseling.Trial Registration NCT03220750, Registered July 18, 2017-Retrospectively registered, https://classic.clinicaltrials.gov/ct2/show/NCT03220750 .

Deciphering maternal-fetal cross-talk in the human placenta during parturition using single-cell RNA sequencing

Labor is a complex physiological process requiring a well-orchestrated dialogue between the mother and fetus. However, the cellular contributions and communications that facilitate maternal-fetal cross-talk in labor have not been fully elucidated. Here, single-cell RNA sequencing (scRNA-seq) was applied to decipher maternal-fetal signaling in the human placenta during term labor. First, a single-cell atlas of the human placenta was established, demonstrating that maternal and fetal cell types underwent changes in transcriptomic activity during labor. Cell types most affected by labor were fetal stromal and maternal decidual cells in the chorioamniotic membranes (CAMs) and maternal and fetal myeloid cells in the placenta. Cell-cell interaction analyses showed that CAM and placental cell types participated in labor-driven maternal and fetal signaling, including the collagen, C-X-C motif ligand (CXCL), tumor necrosis factor (TNF), galectin, and interleukin-6 (IL-6) pathways. Integration of scRNA-seq data with publicly available bulk transcriptomic data showed that placenta-derived scRNA-seq signatures could be monitored in the maternal circulation throughout gestation and in labor. Moreover, comparative analysis revealed that placenta-derived signatures in term labor were mirrored by those in spontaneous preterm labor and birth. Furthermore, we demonstrated that early in gestation, labor-specific, placenta-derived signatures could be detected in the circulation of women destined to undergo spontaneous preterm birth, with either intact or prelabor ruptured membranes. Collectively, our findings provide insight into the maternal-fetal cross-talk of human parturition and suggest that placenta-derived single-cell signatures can aid in the development of noninvasive biomarkers for the prediction of preterm birth.

Challenges in developing Geroscience trials

Geroscience is becoming a major hope for preventing age-related diseases and loss of function by targeting biological mechanisms of aging. This unprecedented paradigm shift requires optimizing the design of future clinical studies related to aging in humans. Researchers will face a number of challenges, including ideal populations to study, which lifestyle and Gerotherapeutic interventions to test initially, selecting key primary and secondary outcomes of such clinical trials, and which age-related biomarkers are most valuable for both selecting interventions and predicting or monitoring clinical responses ("Gerodiagnostics"). This article reports the main results of a Task Force of experts in Geroscience.

Genetic variants associated with spontaneous preterm birth in women from India: a prospective cohort study

Background

Despite having the highest number of preterm births globally, no genomic study on preterm birth was previously published from India or other South-Asian countries.

Methods

We conducted a genome-wide association (GWA) study of spontaneous preterm birth (sPTB) on 6211 women from India. We used a novel resampling procedure to identify the associated single nucleotide polymorphisms (SNPs) followed by haplotype association analysis and imputation.

Findings

We found that 512 maternal SNPs were associated with sPTB (p < 2.51e-3), of which minor allele at 19 SNPs (after Bonferroni correction) had increased genotype relative risk. Haplotypes containing six of the 19 SNPs (rs13011430, rs8179838, rs2327290, rs4798499, rs7629800, and rs13180906) were associated with sPTB (p < 9.9e-4; Bonferroni adjusted p-value <0.05). After imputation in regions around the 19 SNPs, 15 imputed SNPs were found to be associated with sPTB (Bonferroni adjusted p-value <0.05). One of these imputed SNPs, rs35760881, and three other SNPs (rs17307697, rs4308815, and rs10983507) were also reported to be associated with sPTB in women belonging to European ancestry. Moreover, we found that GG genotype at rs1152954, one of the associated SNPs, enhanced risk of sPTB and reduced telomere length.

Interpretation

This is the first study from South Asia on the genome-wide identification of maternal SNPs associated with sPTB. These SNPs are known to alter the expression of genes associated with major pathways in sPTB viz. inflammation, apoptosis, cervical ripening, telomere maintenance, selenocysteine biosynthesis, myometrial contraction, and innate immunity. From a public health perspective, the trans-ethnic association of four SNPs identified in our study may help to stratify women with risk of sPTB in most populations.

Funding

Department of Biotechnology (India), Grand Challenges India - All Children Thriving Program and Biotechnology Industry Research Assistance Council (BIRAC).

TNFα/TNFR1 signal induces excessive senescence of decidua stromal cells in recurrent pregnancy loss

Defects in decidual response are associated with adverse pregnancy outcomes which includes recurrent pregnancy loss (RPL). It is reported that cellular senescence happens during decidualization and pro-senescent decidual response in the luteal phase endometrium is related to RPL. However, the underlying mechanisms of how excessive decidual senescence takes place in RPL decidua cells remain largely unexplored. The senescent phenotype of RPL decidua and tumor necrosis factor receptor 1(TNFR1) expression were analyzed by using our previously published single-cell sequencing dataset of decidua cells from 6 RPL and 5 matched normal decidua, which were further verified by PCR and WB in decidual tissues. Effects of TNFα on the decidual stromal cells (DSCs) senescence and underlying molecular pathways were analyzed using the in vitro decidualization model of human endometrial stromal cells (HESCs). We showed that decidual stroma cells from RPL patients exhibited transcriptomic features of cellular senescence by analysis of single-cell datasets. The TNFα level and TNFR1 expression were increased in RPL decidua tissues. Furthermore, in vitro cell model demonstrated that increased TNFα induced excessive senescence during decidualization and TNFR1/p53/p16 pathway mediates TNFα-induced stromal senescence. In addition, we also found that the expression of IGFBP1 was regulated by TNFα-TNFR1 interaction during decidualization. Taken together, the present findings suggest that the increased secretion of TNFα induced stromal cell excessive senescence in RPL decidua, which is mediated via TNFR1, and thus provide a possible therapeutic target for the treatment of RPL.

Is human labor at term an inflammatory condition?†

Parturition at term in normal pregnancy follows a predictable sequence of events. There is some evidence that a state of inflammation prevails in the reproductive tissues during labor at term, but it is uncertain whether this phenomenon is the initiating signal for parturition. The absence of a clear temporal sequence of inflammatory events prior to labor casts doubt on the concept that normal human labor at term is primarily the result of an inflammatory cascade. This review examines evidence linking parturition and inflammation in order to address whether inflammation is a cause of labor, a consequence of labor, or a separate but related phenomenon. Finally, we identify and suggest ways to reconcile inconsistencies regarding definitions of labor onset in published research, which may contribute to the variability in conclusions regarding the genesis and maintenance of parturition. A more thorough understanding of the processes underlying normal parturition at term may lead to novel insights regarding abnormal labor, including spontaneous preterm labor, preterm premature rupture of the fetal membranes, and dysfunctional labor, and the role of inflammation in each.

Placental circadian lincRNAs and spontaneous preterm birth

Long non-coding RNAs (lncRNAs) have a much higher cell- and/or tissue-specificity compared to mRNAs in most cases, making them excellent candidates for therapeutic applications to reduce off-target effects. Placental long non-coding RNAs have been investigated in the pathogenesis of preeclampsia (often causing preterm birth (PTB)), but less is known about their role in preterm birth. Preterm birth occurs in 11% of pregnancies and is the most common cause of death among infants in the world. We recently identified that genes that drive circadian rhythms in cells, termed molecular clock genes, are deregulated in maternal blood of women with spontaneous PTB (sPTB) and in the placenta of women with preeclampsia. Next, we focused on circadian genes-correlated long intergenic non-coding RNAs (lincRNAs, making up most of the long non-coding RNAs), designated as circadian lincRNAs, associated with sPTB. We compared the co-altered circadian transcripts-correlated lincRNAs expressed in placentas of sPTB and term births using two published independent RNAseq datasets (GSE73712 and GSE174415). Nine core clock genes were up- or downregulated in sPTB versus term birth, where the RORA transcript was the only gene downregulated in sPTB across both independent datasets. We found that five circadian lincRNAs (LINC00893, LINC00265, LINC01089, LINC00482, and LINC00649) were decreased in sPTB vs term births across both datasets (p ≤ .0222, FDR≤.1973) and were negatively correlated with the dataset-specific clock genes-based risk scores (correlation coefficient r = -.65 ∼ -.43, p ≤ .0365, FDR≤.0601). Gene set variation analysis revealed that 65 pathways were significantly enriched by these same five differentially expressed lincRNAs, of which over 85% of the pathways could be linked to immune/inflammation/oxidative stress and cell cycle/apoptosis/autophagy/cellular senescence. These findings may improve our understanding of the pathogenesis of spontaneous preterm birth and provide novel insights into the development of potentially more effective and specific therapeutic targets against sPTB.

Molecular investigation of mechanisms considered to cause preterm premature membrane rupture

Purpose: The aim of this study was to investigate the mRNA expression level of p16, CDK4, CDK6, Cyclin D, RB1, and E2F genes in preterm premature rupture of membrane (PPROM) cases and their roles in etiopathogenesis of PPROM. Materials and Methods: Twenty-one pregnancies with PPROM before 34th gestational weeks (study group) were compared with twenty pregnancies with no complication, who gave birth after 37th gestational-week (control group). Both groups chorioamniotic membranes were compared for mRNA expression of p16, cyclin D, CDK4, CDK6, RB1 and E2F genes. Results: The mRNA expression levels of p16, cyclin D, CDK4, CDK6, RB1and E2F genes decreased in the PPROM group compared to control group at a statistically significant level. Conclusion: Our findings have shown that oxidative stress may not act on the p16 pathway in these cases. In order to understand the molecular mechanism of PPROM, biomarkers of oxidative stress and aging should be evaluated together with other pathways related to aging and oxidative stress in future studies.

Neurons and glial cells acquire a senescent signature after repeated mild traumatic brain injury in a sex-dependent manner

Mild traumatic brain injury (mTBI) is an important public health issue, as it can lead to long-term neurological symptoms and risk of neurodegenerative disease. The pathophysiological mechanisms driving this remain unclear, and currently there are no effective therapies for mTBI. In this study on repeated mTBI (rmTBI), we have induced three mild closed-skull injuries or sham procedures, separated by 24 h, in C57BL/6 mice. We show that rmTBI mice have prolonged righting reflexes and astrogliosis, with neurological impairment in the Morris water maze (MWM) and the light dark test. Cortical and hippocampal tissue analysis revealed DNA damage in the form of double-strand breaks, oxidative damage, and R-loops, markers of cellular senescence including p16 and p21, and signaling mediated by the cGAS-STING pathway. This study identified novel sex differences after rmTBI in mice. Although these markers were all increased by rmTBI in both sexes, females had higher levels of DNA damage, lower levels of the senescence protein p16, and lower levels of cGAS-STING signaling proteins compared to their male counterparts. Single-cell RNA sequencing of the male rmTBI mouse brain revealed activation of the DNA damage response, evidence of cellular senescence, and pro-inflammatory markers reminiscent of the senescence-associated secretory phenotype (SASP) in neurons and glial cells. Cell-type specific changes were also present with evidence of brain immune activation, neurotransmission alterations in both excitatory and inhibitory neurons, and vascular dysfunction. Treatment of injured mice with the senolytic drug ABT263 significantly reduced markers of senescence only in males, but was not therapeutic in females. The reduction of senescence by ABT263 in male mice was accompanied by significantly improved performance in the MWM. This study provides compelling evidence that senescence contributes to brain dysfunction after rmTBI, but may do so in a sex-dependent manner.

Fetal Lung-Derived Exosomes in Term Labor Amniotic Fluid Induce Amniotic Membrane Senescence

The mechanism of parturition is still unclear. Evidence has shown that delivery is associated with cellular senescence of the amniotic membrane. We isolated fetal lung-associated exosomes from the amniotic fluid from term labor (TL-exos) and verified that the exosomes can cause primary human amniotic epithelial cell (hAEC) senescence and apoptosis and can release higher levels of senescence-associated secretory phenotype (SASP)-related molecules and proinflammatory damage-associated molecular patterns (DAMPs) than exosomes isolated from the amniotic fluid from term not in labor (TNIL-exos). The human lung carcinoma cell lines (A549) can be used as an alternative to alveolar type 2 epithelial cells producing pulmonary surfactant. Therefore, we isolated A549 cell-derived exosomes (A549-exos) and found that they can trigger hAEC to undergo the same aging process. Finally, the animal experiments suggested that A549-exos induced vaginal bleeding and preterm labor in pregnant mice. Therefore, we conclude that exosomes derived from fetal lungs in term labor amniotic fluid induce amniotic membrane senescence, which may provide new insight into the mechanism of delivery.

Actions of Bisphenol A on Different Feto-Maternal Compartments Contributing to Preterm Birth

Preterm birth remains to be one of the most prevalent obstetric complications worldwide. Since there are multiple etiological factors associated with this disease process, an integrative literature search in PubMed and Scopus databases on possible mechanism of action and effect of bisphenols on exposure on human or animal placental samples in preterm birth was conducted. From 2332 articles on initial literature search, 63 studies were included for full data extraction. Altogether, several pathways were shown to be possibly affected by bisphenols, leading to dysregulations in structural and endocrine foundation in the placenta, potential induction of senescence and failure of decidualization in the decidua, and possible propagation of inflammation in the fetal membranes. Combined, these actions may eventually counteract bisphenol-induced relaxation of the myometrium and promote contractility alongside fetal membrane weakening. In totality, these individual impairments in gestation-critical processes may lead to failure of maintenance of pregnancy, and thus effecting preterm birth.

Advanced Maternal Age-associated SIRT1 Deficiency Compromises Trophoblast Epithelial-Mesenchymal Transition through an Increase in Vimentin Acetylation

Advanced maternal age (AMA) pregnancies are rapidly increasing and are associated with aberrant trophoblast cell function, poor placentation, and unfavorable pregnancy outcomes, presumably due to premature placental senescence. SIRT1 is an NAD⁺ -dependent deacetylase with well-known antiaging effects, but its connection with placental senescence is unreported. In this study, human term placentas and first-trimester villi were collected from AMA and normal pregnancies, and a mouse AMA model was established by cross breeding young and aged male and female C57 mice. SIRT1 expression and activity in HTR8/SVneo cells were genetically or pharmacologically manipulated. Trophoblast-specific Sirt1-knockout (KO) mouse placentas were generated by mating Elf5-Cre and Sirt1^fl/fl mice. Trophoblast cell mobility was assessed with transwell invasion and wound-healing assays. SIRT1-binding proteins in HTR8/SVneo cells and human placental tissue were identified by mass spectrometry. We identified SIRT1 as the only differentially expressed sirtuin between AMA and normal placentas. It is downregulated in AMA placentas early in the placental life cycle and is barely impacted by paternal age. SIRT1 loss upregulates P53 acetylation and P21 expression and impairs trophoblast invasion and migration. Sirt1-KO mouse placentas exhibit senescence markers and morphological disruption, along with decreased fetal weight. In trophoblasts, SIRT1 interacts with vimentin, regulating its acetylation. In conclusion, SIRT1 promotes trophoblast epithelial-mesenchymal transition (EMT) to enhance invasiveness by modulating vimentin acetylation. AMA placentas are associated with premature senescence during placentation due to SIRT1 loss. Therefore, SIRT1 may be an antiaging therapeutic target for improving placental development and perinatal outcomes in AMA pregnancies.

Dissecting primary and secondary senescence to enable new senotherapeutic strategies

Cellular senescence is a state of stable cell cycle arrest that is known to be elicited in response to different stresses or forms of damage. Senescence limits the replication of old, damaged, and precancerous cells in the short-term but is implicated in diseases and debilities of aging due to loss of regenerative reserve and secretion of a complex combination of factors called the senescence-associated secretory phenotype (SASP). More recently, investigators have discovered that senescent cells induced by these methods (what we term "primary senescent cells") are also capable of inducing other non-senescent cells to undergo senescence - a phenomenon we call "secondary senescence." Secondary senescence has been demonstrated to occur via two broad types of mechanisms. First, factors in the SASP have been shown to be involved in spreading senescence; we call this phenomenon "paracrine senescence." Second, primary senescent cells can induce senescence via an additional group of mechanisms involving cell-to-cell contacts of different types; we term this phenomenon "juxtacrine senescence." "Secondary senescence" in our definition is thus the overarching term for both paracrine and juxtacrine senescence together. By allowing cells that are inherently small in number and incapable of replication to increase in number and possibly spread to anatomically distant locations, secondary senescence allows an initially small number of senescent cells to contribute further to age-related pathologies. We propose that understanding how primary and secondary senescent cells differ from each other and the mechanisms of their spread will enable the development of new rejuvenation therapies to target different senescent cell populations and interrupt their spread, extending human health- and potentially lifespan.

Functional changes in decidual mesenchymal stem/stromal cells are associated with spontaneous onset of labour

Ageing and parturition share common pathways, but their relationship remains poorly understood. Decidual cells undergo ageing as parturition approaches term, and these age-related changes may trigger labour. Mesenchymal stem/stromal cells (MSCs) are the predominant stem cell type in the decidua. Stem cell exhaustion is a hallmark of ageing, and thus ageing of decidual MSCs (DMSCs) may contribute to the functional changes in decidual tissue required for term spontaneous labour. Here, we determine whether DMSCs from patients undergoing spontaneous onset of labour (SOL-DMSCs) show evidence of ageing-related functional changes compared with those from patients not in labour (NIL-DMSCs), undergoing Caesarean section. Placentae were collected from term (37-40 weeks of gestation), SOL (n = 18) and NIL (n = 17) healthy patients. DMSCs were isolated from the decidua basalis that remained attached to the placenta after delivery. DMSCs displayed stem cell-like properties and were of maternal origin. Important cell properties and lipid profiles were assessed and compared between SOL- and NIL-DMSCs. SOL-DMSCs showed reduced proliferation and increased lipid peroxidation, migration, necrosis, mitochondrial apoptosis, IL-6 production and p38 MAPK levels compared with NIL-DMSCs (P < 0.05). SOL- and NIL-DMSCs also showed significant differences in lipid profiles in various phospholipids (phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine), sphingolipids (ceramide, sphingomyelin), triglycerides and acyl carnitine (P < 0.05). Overall, SOL-DMSCs had altered lipid profiles compared with NIL-DMSCs. In conclusion, SOL-DMSCs showed evidence of ageing-related reduced functionality, accumulation of cellular damage and changes in lipid profiles compared with NIL-DMSCs. These changes may be associated with term spontaneous labour.

Integrated trajectories of the maternal metabolome, proteome, and immunome predict labor onset

Estimating the time of delivery is of high clinical importance because pre- and postterm deviations are associated with complications for the mother and her offspring. However, current estimations are inaccurate. As pregnancy progresses toward labor, major transitions occur in fetomaternal immune, metabolic, and endocrine systems that culminate in birth. The comprehensive characterization of maternal biology that precedes labor is key to understanding these physiological transitions and identifying predictive biomarkers of delivery. Here, a longitudinal study was conducted in 63 women who went into labor spontaneously. More than 7000 plasma analytes and peripheral immune cell responses were analyzed using untargeted mass spectrometry, aptamer-based proteomic technology, and single-cell mass cytometry in serial blood samples collected during the last 100 days of pregnancy. The high-dimensional dataset was integrated into a multiomic model that predicted the time to spontaneous labor [R = 0.85, 95% confidence interval (CI) [0.79 to 0.89], P = 1.2 × 10^-40, N = 53, training set; R = 0.81, 95% CI [0.61 to 0.91], P = 3.9 × 10^-7, N = 10, independent test set]. Coordinated alterations in maternal metabolome, proteome, and immunome marked a molecular shift from pregnancy maintenance to prelabor biology 2 to 4 weeks before delivery. A surge in steroid hormone metabolites and interleukin-1 receptor type 4 that preceded labor coincided with a switch from immune activation to regulation of inflammatory responses. Our study lays the groundwork for developing blood-based methods for predicting the day of labor, anchored in mechanisms shared in preterm and term pregnancies.

Oxidative stress promotes cellular damages in the cervix: implications for normal and pathologic cervical function in human pregnancy†

A physiologic increase in reactive oxygen species throughout pregnancy is required to remodel the cervix. Oxidative stress can cause cellular damage that contributes to dysfunctional tissue. This study determined the oxidative stress-induced cell fate of human cervical epithelial and cervical stromal cells. We treated the ectocervical and endocervical epithelial cells and cervical stromal cells with cigarette smoke extract, an oxidative stress inducer, for 48 h. Cell viability (crystal violet assay); cell cycle, apoptosis, and necrosis (flow cytometry); senescence (senescence-associated β-galactosidase staining); autophagy (staining for autophagosome protein, microtubule-associated protein 1 light chain 3B); stress signaler p38 mitogen-activated protein kinases pathway activation (western blot analyses); and inflammation by measuring interleukin-6 (enzyme-linked immunosorbent assay) were conducted after 48 h of cigarette smoke extract treatment. Oxidative stress induced reactive oxygen species production in cervical cells, which was inhibited by N-acetylcysteine. Oxidative stress promoted cell cycle arrest and induced necrosis in cervical cells. High senescence and low autophagy were observed in cervical stromal cells under oxidative stress. Conversely, senescence was low and autophagy was high in endocervical epithelial cells. Oxidative stress induced p38 mitogen-activated protein kinases (p38MAPK) activation in all cervical cells but only increased interleukin-6 production by the ectocervical epithelial cells. Inhibition of interleukin-6 production by a p38 mitogen-activated protein kinases inhibitor confirmed the activation of an oxidative stress-induced pathway. In conclusion, oxidative stress can promote cell death and sterile inflammation that is mediated by p38 mitogen-activated protein kinases activation in the cellular components of the cervix. These cellular damages may contribute to the normal and premature cervical ripening, which can promote preterm birth.

Clinical consequences of defective decidualization

Decidualization is characterized by a series of genetic, metabolic, morphological, biochemical, vascular and immune changes occurring in the endometrial stroma in response to the implanting embryo or even before conception and involves the stromal cells of the endometrium. It is a fundamental reproductive event occurring in mammalian species with hemochorial placentation. A growing body of experimental and clinical evidence strongly suggests that defective or disrupted decidualization contributes to the establishment of an inappropriate maternal-fetal interface. This has relevant clinical consequences, ranging from recurrent implantation failure and recurrent pregnancy loss in early pregnancy to several significant complications of advanced gestation. Moreover, recent evidence indicates that selected diseases of the endometrium, such as chronic endometritis and endometriosis, can have a detrimental impact on the decidualization response in the endometrium and may help explain some aspects of the reduced reproductive outcome associated with these conditions. Further research efforts are needed to fully understand the biomolecular mechanisms ans events underlying an abnormal decidualization response. This will permit the development of new diagnostic and therapeutic strategies aimed to improve the likelihood of achieveing a successful pregnancy.

Senescent Changes and Endoplasmic Reticulum Stress May Be Involved in the Pathogenesis of Missed Miscarriage

Background

Senescence is involved in many complications of pregnancy. However, whether senescent changes are also associated with missed miscarriage has not been fully investigated.

Methods

The levels of p16, p21, and γH2AX, markers of senescence, were measured in placentas collected from women with missed miscarriage by immunohistochemistry and Western blotting. Levels of misfolded proteins in missed miscarriage placentas or normal first-trimester placenta that had been treated with H₂O₂ (100 μM) or extracellular vesicles (EVs) collected from missed miscarriage placental explant culture were measured by fluorescent compound, thioflavin-T. The production of reactive oxygen species (ROS) by missed miscarriage placentas was measured by CellROX^® Deep Red.

Results

Increased levels of p16, p21, and γH2AX were presented in missed miscarriage placentas compared to controls. Increased levels of misfolded proteins were shown in missed miscarriage placentas, but not in EVs that were collected from missed miscarriage placentas. The ROS production was significantly increased in missed miscarriage placental explant cultures. Increased levels of misfolded proteins were seen in the normal first-trimester placenta that had been treated with H₂O₂ compared to untreated.

Conclusion

Our data demonstrate that there are increases in senescence and endoplasmic reticulum stress and ROS production in missed miscarriage placenta. Oxidative stress and an accumulation of misfolded proteins in missed miscarriage placentas may contribute to the changes of senescence and endoplasmic reticulum stress seen in missed miscarriage placentas.

Cervical pessary to prevent preterm birth in asymptomatic high-risk women: a systematic review and meta-analysis

BACKGROUND

Randomized controlled trials that have assessed the efficacy of cervical pessary to prevent preterm birth in asymptomatic high-risk women have reported conflicting results.

OBJECTIVE

To evaluate the efficacy and safety of cervical pessary to prevent preterm birth and adverse perinatal outcomes in asymptomatic high-risk women.

DATA SOURCES

MEDLINE, EMBASE, POPLINE, CINAHL, and LILACS (from their inception to October 31, 2019), Cochrane databases, Google Scholar, bibliographies, and conference proceedings.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared cervical pessary with standard care (no pessary) or alternative interventions in asymptomatic women at high risk for preterm birth.

STUDY APPRAISAL AND SYNTHESIS METHODS

The systematic review was conducted according to the Cochrane Handbook guidelines. The primary outcome was spontaneous preterm birth <34 weeks of gestation. Secondary outcomes included adverse pregnancy, maternal, and perinatal outcomes. Pooled relative risks with 95% confidence intervals were calculated. Quality of evidence was assessed using the GRADE methodology.

RESULTS

Twelve studies (4687 women and 7167 fetuses/infants) met the inclusion criteria: 8 evaluated pessary vs no pessary in women with a short cervix, 2 assessed pessary vs no pessary in unselected multiple gestations, and 2 compared pessary vs vaginal progesterone in women with a short cervix. There were no significant differences between the pessary and no pessary groups in the risk of spontaneous preterm birth <34 weeks of gestation among singleton gestations with a cervical length ≤25 mm (relative risk, 0.80; 95% confidence interval, 0.43-1.49; 6 trials, 1982 women; low-quality evidence), unselected twin gestations (relative risk, 1.05; 95% confidence interval, 0.79-1.41; 1 trial, 1177 women; moderate-quality evidence), twin gestations with a cervical length <38 mm (relative risk, 0.75; 95% confidence interval, 0.41-1.36; 3 trials, 1128 women; low-quality evidence), and twin gestations with a cervical length ≤25 mm (relative risk; 0.72, 95% confidence interval, 0.25-2.06; 2 trials, 348 women; low-quality evidence). Overall, no significant differences were observed between the pessary and no pessary groups in preterm birth <37, <32, and <28 weeks of gestation, and most adverse pregnancy, maternal, and perinatal outcomes (low- to moderate-quality evidence for most outcomes). There were no significant differences in the risk of spontaneous preterm birth <34 weeks of gestation between pessary and vaginal progesterone in singleton gestations with a cervical length ≤25 mm (relative risk, 0.99; 95% confidence interval, 0.54-1.83; 1 trial, 246 women; low-quality evidence) and twin gestations with a cervical length <38 mm (relative risk, 0.73; 95% confidence interval, 0.46-1.18; 1 trial, 297 women; very low-quality evidence). Vaginal discharge was significantly more frequent in the pessary group than in the no pessary and vaginal progesterone groups (relative risks, ∼2.20; high-quality evidence).

CONCLUSION

Current evidence does not support the use of cervical pessary to prevent preterm birth or to improve perinatal outcomes in singleton or twin gestations with a short cervix and in unselected twin gestations.

Ageing in human parturition: impetus of the gestation clock in the decidua†

Despite sharing many common features, the relationship between ageing and parturition remains poorly understood. The decidua is a specialized lining of endometrial tissue, which develops in preparation for pregnancy. The structure and location of the decidua support its role as the physical scaffold for the growing embryo and placenta, and thus, it is vital to sustain pregnancy. Approaching term, the physical support properties of the decidua are naturally weakened to permit parturition. In this review, we hypothesize that the natural weakening of decidual tissue at parturition is promoted by the ageing process. Studies of the ageing-related functional and molecular changes in the decidua at parturition are reviewed and classified using hallmarks of ageing as the framework. The potential roles of decidual mesenchymal stem/stromal cell (DMSC) ageing in labor are also discussed because, although stem cell exhaustion is also a hallmark of ageing, its role in labor is not completely understood. In addition, the potential roles of extracellular vesicles secreted by DMSCs in labor, and their parturition-related miRNAs, are reviewed to gain further insight into this research area. In summary, the literature supports the notion that the decidua ages as the pregnancy progresses, and this may facilitate parturition, suggesting that ageing is the probable impetus of the gestational clocks in the decidua. This conceptual framework was developed to provide a better understanding of the natural ageing process of the decidua during parturition as well as to encourage future studies of the importance of healthy ageing for optimal pregnancy outcomes.

Cellular Senescence and Senotherapies in the Kidney: Current Evidence and Future Directions

Cellular senescence refers to a cellular phenotype characterized by an altered transcriptome, pro-inflammatory secretome, and generally irreversible growth arrest. Acutely senescent cells are widely recognized as performing key physiological functions in vivo promoting normal organogenesis, successful wound repair, and cancer defense. In contrast, the accumulation of chronically senescent cells in response to aging, cell stress, genotoxic damage, and other injurious stimuli is increasingly recognized as an important contributor to organ dysfunction, tissue fibrosis, and the more generalized aging phenotype. In this review, we summarize our current knowledge of the role of senescent cells in promoting progressive fibrosis and dysfunction with a particular focus on the kidney and reference to other organ systems. Specific differences between healthy and senescent cells are reviewed along with a summary of several experimental pharmacological approaches to deplete or manipulate senescent cells to preserve organ integrity and function with aging and after injury. Finally, key questions for future research and clinical translation are discussed.

The link between endometrial stromal cell senescence and decidualization in female fertility: the art of balance

Cell senescence seems to be an ambivalent biological phenomenon in many aspects. At the cellular level it is considered as an irreversible cell-cycle arrest commonly caused by the DNA damage. Senescent cells harbor a lot of impairments in various intracellular systems. Presence of senescent cells within tissues should ultimately lead to their malfunctioning. However, the interlink between cellular senescence and tissue/organismal functioning is far from always being unidirectional. The entangled and complex relationship between senescence and tissue-specific decidual differentiation of endometrial stromal cells (ESCs) is the excellent example reflecting dualism of cellular senescence. ESCs decidualization conditions endometrium responsiveness to embryonic signals and plays a critical role in embryo biosensoring, selection and implantation. Based on the analysis of the existing literary data, here we will try (1) to puzzle out how cellular senescence simultaneously may be an integral part of normal decidualization and may be involved in the progression of repeated implantation failures and recurrent pregnancy losses; (2) to suppose the sequence of cellular events reflecting the role of ESCs' senescence during normal and impaired decidualization. Together, the deep scan of the interlink between ESCs' senescence and decidualization will allow to suggest the preferable application scheme for senolytics targeting senescent cells as a possible approach to restore impaired endometrial receptivity and thus to increase the effectiveness of in vitro fertilization cycles.

Telomere Length and Telomerase Activity in Foetal Membranes from Term and Spontaneous Preterm Births

The reduction of telomere length, the protective cap structures of chromosomes, is one of the biomarkers of senescence (a mechanism of ageing), and ageing of foetal gestational tissues is associated with both term and preterm parturition. A mechanism regulating telomere length is the activity of telomerase, an enzyme that adds telomere fragments during DNA replication and cell division; however, its role in regulating telomere length is not well studied in gestational tissues. The objective of this study is to correlate telomere length and telomerase activity in foetal membranes from term and spontaneous preterm births. Foetal membrane samples were collected from pregnant women experiencing term labour (TL), term not in labour (TNL), preterm premature rupture of membranes (pPROM) and spontaneous preterm labour (PTL) with intact membranes (n = 20/group). Telomere length and telomerase activity were analyzed by relative quantification (T/S), real-time PCR and PCR-based fluorometric detection, respectively. Data were analyzed by ANOVA or the Kruskal-Wallis test. Demographic variables were not statistically different among the groups. Foetal membranes from the TL group showed telomere length reduction compared with those from the others (p < 0.0002). Telomerase activity did not change in foetal membranes irrespective of pregnancy outcome. Telomere shortening in foetal membranes is suggestive of senescence associated with triggering of labour at term; however, this is likely independent of telomerase activity, while prematurity may be associated with senescence, but due to other mechanisms than telomere length reduction in foetal membranes.

EBF1 Gene mRNA Levels in Maternal Blood and Spontaneous Preterm Birth

Genetic variants of six genes (EBF1, EEFSEC, AGTR2, WNT4, ADCY5, and RAP2C) have been linked recently to gestational duration and/or spontaneous preterm birth (sPTB). Our goal was to examine sPTB in relation to maternal blood mRNA levels of these genes. We used a public gene expression dataset (GSE59491) derived from maternal blood in trimesters 2 and 3 that included women with sPTB (n = 51) and term births (n = 106) matched for maternal age, race/ethnicity, pre-pregnancy body mass index, smoking during pregnancy, and parity. T tests were used to examine mRNA mean differences (sPTB vs term) within and across trimesters, and logistic regression models with mRNA quartiles were applied to assess associations between candidate gene mRNA levels and sPTB. Based on these analyses, one significant candidate gene was used in a Gene Set Enrichment Analysis (GSEA) to identify related gene sets. These gene sets were then compared with the ones previously linked to sPTB in the same samples. Our results indicated that among women in the lowest quartile of EBF1 mRNA in the 2nd or 3rd trimester, the odds ratio for sPTB was 2.86 (95%CI 1.08, 7.58) (p = 0.0349, false discovery rate (FDR) = 0.18) and 4.43 (95%CI 1.57, 12.50) (p = 0.0049, FDR = 0.06), respectively. No other candidate gene mRNAs were significantly associated with sPTB. In GSEA, 24 downregulated gene sets were correlated with 2nd trimester low EBF1 mRNA and part of previous sPTB-associated gene sets. In conclusion, mRNA levels of EBF1 in maternal blood may be useful in detecting increased risk of sPTB as early as 2nd trimester. The potential underlying mechanism might involve maternal-fetal immune and cell cycle/apoptosis pathways.

Complementary and distinct roles of autophagy, apoptosis and senescence during early inner ear development

The development of the inner ear complex cytoarchitecture and functional geometry requires the exquisite coordination of a variety of cellular processes in a temporal manner. At early stages of inner ear development several rounds of cell proliferation in the otocyst promote the growth of the structure. The apoptotic program is initiated in exceeding cells to adjust cell type numbers. Apoptotic cells are cleared by phagocytic cells that recognize the phosphatidylserine residues exposed in the cell membrane thanks to the energy supplied by autophagy. Specific molecular programs determine hair and supporting cell fate, these populations are responsible for the functions of the adult sensory organ: detection of sound, position and acceleration. The neurons that transmit auditory and balance information to the brain are also born at the otocyst by neurogenesis facilitated by autophagy. Cellular senescence participates in tissue repair, cancer and aging, situations in which cells enter a permanent cell cycle arrest and acquire a highly secretory phenotype that modulates their microenvironment. More recently, senescence has also been proposed to take place during vertebrate development in a limited number of transitory structures and organs; among the later, the endolymphatic duct in the inner ear. Here, we review these cellular processes during the early development of the inner ear, focusing on how the most recently described cellular senescence participates and cooperates with proliferation, apoptosis and autophagy to achieve otic morphogenesis and differentiation.