Oxidative stress-induced downregulation of glycogen synthase kinase 3 beta in fetal membranes promotes cellular senescence†

Keap1-independent Nrf2 regulation: A novel therapeutic target for treating kidney disease

The transcription factor NF-E2-related factor 2 (Nrf2) is a master regulator of antioxidant responses in mammals, where it plays a critical role in detoxification, maintaining cellular homeostasis, combating inflammation and fibrosis, and slowing disease progression. Kelch-like ECH-associated protein 1 (Keap1), an adaptor subunit of Cullin 3-based E3 ubiquitin ligase, serves as a critical sensor of oxidative and electrophilic stress, regulating Nrf2 activity by sequestering it in the cytoplasm, leading to its proteasomal degradation and transcriptional repression. However, the clinical potential of targeting the Keap1-dependent Nrf2 regulatory pathway has been limited. This is evidenced by early postnatal lethality in Keap1 knockout mice, as well as significant adverse events after pharmacological blockade of Keap1 in human patients with Alport syndrome as well as in those with type 2 diabetes mellitus and chronic kidney disease. The exact underlying mechanisms remain elusive, but may involve non-specific and systemic activation of the Nrf2 antioxidant response in both injured and normal tissues. Beyond Keap1-dependent regulation, Nrf2 activity is modulated by Keap1-independent mechanisms, including transcriptional, epigenetic, and post-translational modifications. In particular, GSK3β has emerged as a critical convergence point for these diverse signaling pathways. Unlike Keap1-dependent regulation, GSK3β-mediated Keap1-independent Nrf2 regulation does not affect basal Nrf2 activity but modulates its response at a delayed/late phase of cellular stress. This allows fine-tuning of the inducibility, magnitude, and duration of the Nrf2 response specifically in stressed or injured tissues. As one of the most metabolically active organs, the kidney is a major source of production of reactive oxygen and nitrogen species and also a vulnerable organ to oxidative damage. Targeting the GSK3β-mediated Nrf2 regulatory pathway represents a promising new approach for the treatment of kidney disease.

Long-term outcome of childhood and adolescent patients with craniopharyngiomas: a single center retrospective experience

BACKGROUND

The treatment of craniopharyngiomas (CPs) poses challenges due to their proximity to critical neural structures, the risk of serious complications, and the impairment of quality of life after treatment. However, long-term prognostic data are still scarce. Therefore, the purpose of this retrospective study is to evaluate the long-term outcomes of patients with CPs after treatment.

MATERIAL AND METHOD

Our center retrospectively collected data on 83 children and adolescents who underwent craniopharyngioma surgery between 2001 and 2020. The medical records and radiological examination results of the patient were reviewed.

RESULTS

Outcomes were analysed for 80/83 patients who completed follow-up: 50 males (62.5%) and 30 females (37.5%), the median age at the time of diagnosis 8.4 (5.3-12.2) years. The median follow-up time was 136 (61-280) months. The 5-, 10- and 15-year overall survival (OS) rates were 100%, 98.3%, and 94.6%, respectively. Accordingly, the disease-specific survival (DSS) rates were 100%, 98.3% and 94.6%, respectively. Overall progression-free survival (PFS) rates after 5, 10 and 15 years of follow-up in the entire group were 85.4%, 72.2% and 70.1%, respectively. Multivariate analysis found that surgical resection grade was only associated with PFS outcomes [ HR = 0.031 (95% CI: 0.006, 0.163), P < 0.001], without improving OS or DSS. After undergoing recombinant human growth hormone (rhGH) replacement therapy, the total cholesterol (TC) level decreased by 0.90 mmol/L compared to baseline (P = 0.002), and the low-density lipoprotein cholesterol (LDL-C) level decreased by 0.73 mmol/L compared to baseline (P = 0.010). For liver function, compared with baseline data, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) showed a downward trend, but did not reach a statistically significant level (P > 0.05).

CONCLUSION

Surgical treatment of CPs provides good long-time OS and DSS, even though combined with radiotherapy in only selected cases. Gross total resection (GTR) is individual positive prognostic factor. rhGH replacement could improve CPs lipid profile.

Naringin Prevents Diabetic-Induced Dysmetabolism in Male Wistar Rats by Modulating GSK-3 Activities and Oxidative Stress-Dependent Pathways

Type 2 diabetes mellitus (T2DM), characterized by insulin resistance and glucose dysmetabolism, is a major metabolic disorder accompanied with health and financial burden. Recently, research findings showed that orange peel extract (OPE) has health benefits such as improved insulin sensitivity and glucose metabolism. The present study aimed at establishing the role of naringin from OPE on T2DM-induced glucose and lipid dysmetabolism. Thirty male (30) Wistar rats were randomized into five groups: control, diabetes, diabetes + naringin, diabetes + orange peel, and diabetes + metformin. Oral administration was once per day for 28 days. After 28 days of treatment, naringin ameliorated the diabetes-induced increase in blood sugar, homeostatic model assessment (HOMA) IR, triglyceride, total cholesterol, triglyceride/high density lipoprotein, total cholesterol/high density lipoprotein, triglyceride glucose index, glucose synthase kinase-3, lactate, lactate dehydrogenase, malondialdehyde, c-reactive protein, and tumor necrosis factor α compared with the diabetic untreated animals. Furthermore, naringin reversed diabetes-induced decrease in serum insulin, HOMA B, HOMA S, quantitative insulin-sensitivity check index, high-density lipoprotein, total antioxidant capacity, superoxide dismutase, catalase, glucose transporter-4, and hepatic glycogen. This study showed that naringin prevented diabetes-induced dysglycemia and dyslipidemia via glucose synthase kinase-3 and oxidative stress-dependent pathways.

Imidacloprid unique and repeated treatment produces cholinergic transmission disruption and apoptotic cell death in SN56 cells

Imidacloprid (IMI), the most widely used worldwide neonicotinoid biocide, produces cognitive disorders after repeated and single treatment. However, little was studied about the possible mechanisms that produce this effect. Cholinergic neurotransmission regulates cognitive function. Most cholinergic neuronal bodies are present in the basal forebrain (BF), regulating memory and learning process, and their dysfunction or loss produces cognition decline. BF SN56 cholinergic wild-type or acetylcholinesterase (AChE), β-amyloid-precursor-protein (βAPP), Tau, glycogen-synthase-kinase-3-beta (GSK3β), beta-site-amyloid-precursor-protein-cleaving enzyme 1 (BACE1), and/or nuclear-factor-erythroid-2-related-factor-2 (NRF2) silenced cells were treated for 1 and 14 days with IMI (1 μM-800 μM) with or without recombinant heat-shock-protein-70 (rHSP70), recombinant proteasome 20S (rP20S) and with or without N-acetyl-cysteine (NAC) to determine the possible mechanisms that mediate this effect. IMI treatment for 1 and 14 days altered cholinergic transmission through AChE inhibition, and triggered cell death partially through oxidative stress generation, AChE-S overexpression, HSP70 downregulation, P20S inhibition, and Aβ and Tau peptides accumulation. IMI produced oxidative stress through reactive oxygen species production and antioxidant NRF2 pathway downregulation, and induced Aβ and Tau accumulation through BACE1, GSK3β, HSP70, and P20S dysfunction. These results may assist in determining the mechanisms that produce cognitive dysfunction observed following IMI exposure and provide new therapeutic tools.

GSK-3: An "Ace" Among Kinases

Background: Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase known to participate in the regulation of β-catenin signaling (Wnt signaling). This aids in the establishment of a multicomponent destruction complex that stimulates phosphorylation, leading to the destruction of β-catenin. Evidence about the role of increasingly active β-catenin signaling is involved in many forms of human cancer. The understanding of GSK-3 remains elusive as recent research aims to focus on developing potent GSK-3 inhibitors to target this kinase. Objective: This short review aims to highlight the regulation of GSK-3 with emphasis on Wnt signaling while highlighting its interaction with miRNAs corresponding to pluripotency and epithelial mesenchymal transition substantiating this kinase as an "Ace" among kinases in regulation of cellular processes. Result: Significant findings of miRNA regulation by GSK-3 exemplify the underpinnings of kinase-mediated transcriptional regulation in cancers. Conclusion: The review provides evidence on the role of GSK-3 as a possible master regulator of proteins and noncoding RNA, thereby implicating the fate of a cell.

Cellular senescence: A novel therapeutic target for central nervous system diseases

The underlying mechanisms of diseases affecting the central nervous system (CNS) remain unclear, limiting the development of effective therapeutic strategies. Remarkably, cellular senescence, a biological phenomenon observed in cultured fibroblasts in vitro, is a crucial intrinsic mechanism that influences homeostasis of the brain microenvironment and contributes to the onset and progression of CNS diseases. Cellular senescence has been observed in disease models established in vitro and in vivo and in bodily fluids or tissue components from patients with CNS diseases. These findings highlight cellular senescence as a promising target for preventing and treating CNS diseases. Consequently, emerging novel therapies targeting senescent cells have exhibited promising therapeutic effects in preclinical and clinical studies on aging-related diseases. These innovative therapies can potentially delay brain cell loss and functional changes, improve the prognosis of CNS diseases, and provide alternative treatments for patients. In this study, we examined the relevant advancements in this field, particularly focusing on the targeting of senescent cells in the brain for the treatment of chronic neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease, and multiple sclerosis) and acute neurotraumatic insults (e.g., ischemic stroke, spinal cord injury, and traumatic brain injury).

Spatial transcriptomics of fetal membrane-Decidual interface reveals unique contributions by cell types in term and preterm births

During pregnancy, two fetomaternal interfaces, the placenta-decidua basalis and the fetal membrane-decidua parietals, allow for fetal growth and maturation and fetal-maternal crosstalk, and protect the fetus from infectious and inflammatory signaling that could lead to adverse pregnancy outcomes. While the placenta has been studied extensively, the fetal membranes have been understudied, even though they play critical roles in pregnancy maintenance and the initiation of term or preterm parturition. Fetal membrane dysfunction has been associated with spontaneous preterm birth (PTB, < 37 weeks gestation) and preterm prelabor rupture of the membranes (PPROM), which is a disease of the fetal membranes. However, it is unknown how the individual layers of the fetal membrane decidual interface (the amnion epithelium [AEC], the amnion mesenchyme [AMC], the chorion [CTC], and the decidua [DEC]) contribute to these pregnancy outcomes. In this study, we used a single-cell transcriptomics approach to unravel the transcriptomics network at spatial levels to discern the contributions of each layer of the fetal membranes and the adjoining maternal decidua during the following conditions: scheduled caesarian section (term not in labor [TNIL]; n = 4), vaginal term in labor (TIL; n = 3), preterm labor with and without rupture of membranes (PPROM; n = 3; and PTB; n = 3). The data included 18,815 genes from 13 patients (including TIL, PTB, PPROM, and TNIL) expressed across the four layers. After quality control, there were 11,921 genes and 44 samples. The data were processed by two pipelines: one by hierarchical clustering the combined cases and the other to evaluate heterogeneity within the cases. Our visual analytical approach revealed spatially recognized differentially expressed genes that aligned with four gene clusters. Cluster 1 genes were present predominantly in DECs and Cluster 3 centered around CTC genes in all labor phenotypes. Cluster 2 genes were predominantly found in AECs in PPROM and PTB, while Cluster 4 contained AMC and CTC genes identified in term labor cases. We identified the top 10 differentially expressed genes and their connected pathways (kinase activation, NF-κB, inflammation, cytoskeletal remodeling, and hormone regulation) per cluster in each tissue layer. An in-depth understanding of the involvement of each system and cell layer may help provide targeted and tailored interventions to reduce the risk of PTB.

Histologic Evidence of Epithelial-Mesenchymal Transition and Autophagy in Human Fetal Membranes

Preterm, prelabor rupture of the human fetal membranes (pPROM) is involved in 40% of spontaneous preterm births worldwide. Cellular-level disturbances and inflammation are effectors of membrane degradation, weakening, and rupture. Maternal risk factors induce oxidative stress (OS), senescence, and senescence-associated inflammation of the fetal membranes as reported mechanisms related to pPROM. Inflammation can also arise in fetal membrane cells (amnion/chorion) due to OS-induced autophagy and epithelial-mesenchymal transition (EMT). Autophagy, EMT, and their correlation in pPROM, along with OS-induced autophagy-related changes in amnion and chorion cells in vitro, were investigated. Immunocytochemistry staining of cytokeratin-18 (epithelial marker)/vimentin (mesenchymal marker) and proautophagy-inducing factor LC3B were performed in fetal membranes from pPROM, term not in labor, and term labor. Ultrastructural changes associated with autophagy were verified by transmission electron microscopy of the fetal membranes and in cells exposed to cigarette smoke extract (an OS inducer). EMT and LC3B staining was compared in the chorion from pPROM versus term not in labor. Transmission electron microscopy confirmed autophagosome formation in pPROM amnion and chorion. In cell culture, autophagosomes were formed in the amnion with OS treatment, while autophagosomes were accumulated in both cell types with autophagy inhibition. This study documents the association between pPROMs and amniochorion autophagy and EMT, and supports a role for OS in inducing dysfunctional cells that increase inflammation, predisposing membranes to rupture.

Frontiers in the Etiology and Treatment of Preterm Premature Rupture of Membrane: From Molecular Mechanisms to Innovative Therapeutic Strategies

Preterm premature rupture of membranes (pPROM) poses a significant threat to fetal viability and increases the risk for newborn morbidities. The perinatal period of preterm infants affected by pPROM is often characterized by higher rates of mortality and morbidity, with associated risks of cerebral palsy, developmental delays, compromised immune function, respiratory diseases, and sensory impairments. pPROM is believed to result from a variety of causes, including but not limited to microbially induced infections, stretching of fetal membranes, oxidative stress, inflammatory responses, and age-related changes in the fetal-placental interface. Maternal stress, nutritional deficiencies, and medically induced procedures such as fetoscopy are also considered potential contributing factors to pPROM. This comprehensive review explores the potential etiologies leading to pPROM, delves into the intricate molecular mechanisms through which these etiologies cause membrane ruptures, and provides a concise overview of diagnostic and treatment approaches for pPROM. Based on available therapeutic options, this review proposes and explores the possibilities of utilizing a novel composite hydrogel composed of amniotic membrane particles for repairing ruptured fetal membranes, thereby holding promise for its clinical application.

Review on new approach methods to gain insight into the feto-maternal interface physiology

Non-human animals represent a large and important feature in the history of biomedical research. The validity of their use, in terms of reproducible outcomes and translational confidence to the human situation, as well as ethical concerns surrounding that use, have been and remain controversial topics. Over the last 10 years, the communities developing microphysiological systems (MPS) have produced new approach method (NAMs) such as organoids and organs-on-a-chip. These alternative methodologies have shown indications of greater reliability and translatability than animal use in some areas, represent more humane substitutions for animals in these settings, and - with continued scientific effort - may change the conduct of basic research, clinical studies, safety testing, and drug development. Here, we present an introduction to these more human-relevant methodologies and suggest how a suite of pregnancy associated feto-maternal interface system-oriented NAMs may be integrated as reliable partial-/full animal replacements for investigators, significantly aid animal-/environmental welfare, and improve healthcare outcomes.

Guggulsterone protects against lipopolysaccharide-induced inflammation and lethal endotoxemia via heme oxygenase-1

Guggulsterone (GS) is a phytosterol used to treat inflammatory diseases. Although many studies have examined the anti-inflammatory activities of GS, the detailed mechanisms of GS in lipopolysaccharide (LPS)-induced inflammation and endotoxemia have not yet been examined. Therefore, we investigated the anti-inflammatory effects of GS on LPS-induced inflammation. In murine peritoneal macrophages, the anti-inflammatory activity of GS was primarily mediated by heme oxygenase-1 (HO-1) induction. HO-1 induction by GS was mediated by GSH depletion and reactive oxygen species (ROS) production. The ROS generated by GS caused the phosphorylation of GSK3β (ser9/21) and p38, leading to the translocation of nuclear factor erythroid-related factor 2 (Nrf2), which ultimately induced HO-1. In addition, GS pretreatment significantly inhibited inducible nitric oxide synthase (iNOS), iNOS-derived NO, and COX-2 protein and mRNA expression, and production of COX-derived prostaglandin PGE2, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). In a mouse model of endotoxemia, GS treatment prolonged survival and inhibited the expression of inflammatory mediators, including IL-1β, IL-6, and TNF-α. GS treatment also inhibited LPS-induced liver injury. These results suggest that GS-induced HO-1 could exert anti-inflammatory effects via ROS-dependent GSK (ser21/9)-p38 phosphorylation and nuclear translocation of Nrf2.

Decreased level of TREM like Transcript 1 (TLT-1) is associated with prematurity and promotes the in-utero inflammatory response to maternal lipopolysaccharide (LPS) exposure

PROBLEM

The occurrence of preterm birth is associated with multiple factors including bleeding, infection and inflammation. Platelets are mediators of hemostasis and can modulate inflammation through interactions with leukocytes. TREM like Transcript 1 (TLT-1) is a type 1 single Ig domain receptor on activated platelets. In adults, it plays a protective role by dampening the inflammatory response and facilitating platelet aggregation at sites of vascular injury. TLT-1 is expressed in human placenta and found in cord blood. We thus hypothesized that TLT-1 deficiency is associated with prematurity and fetal inflammation.

METHOD OF STUDY

To test this hypothesis, we examined cord blood levels of soluble TLT-1 (sTLT) in premature and term infants and compared the inflammatory response in C57BL/6 (WT) and TLT-1-/- (treml1-/- , KO) mice given intraperitoneal LPS mid-gestation RESULTS: The preterm infant cord blood level of sTLT was significantly lower than that found at term. On exposure to LPS, histology of KO (as compared to WT) placenta and decidua showed increased hemorrhage, and KO decidual RNA expression of IL-10 was significantly lower. KO fetal interface tissues (placenta, membranes, amniotic fluid) over time showed increased expression of inflammatory cytokines such as IL-6, IFN-γ, and TNF, but not MCP-1. However, fetal organs showed similar levels.

CONCLUSION

There is a potential association between insufficient TLT-1 expression and increased fetal inflammatory responses in the setting of prematurity. The data support further study of TLT-1 in the mechanistic link between bleeding, inflammation and preterm birth, and perhaps as a biomarker in human pregnancy.

Flip a coin: cell senescence at the maternal-fetal interface†

During pregnancy, cell senescence at the maternal-fetal interface is required for maternal well-being, placental development, and fetal growth. However, recent reports have shown that aberrant cell senescence is associated with multiple pregnancy-associated abnormalities, such as preeclampsia, fetal growth restrictions, recurrent pregnancy loss, and preterm birth. Therefore, the role and impact of cell senescence during pregnancy requires further comprehension. In this review, we discuss the principal role of cell senescence at the maternal-fetal interface, emphasizing its "bright side" during decidualization, placentation, and parturition. In addition, we highlight the impact of its deregulation and how this "dark side" promotes pregnancy-associated abnormalities. Furthermore, we discuss novel and less invasive therapeutic practices associated with the modulation of cell senescence during pregnancy.

Silencing P38 MAPK reduces cellular senescence in human fetal chorion trophoblast cells

PROBLEM

Amniochorion senescence generates mechanistic signals to initiate parturition. Activation of p38 mitogen-activated kinase (MAPK) in fetal amnion cells is a key mediator of senescence as well as epithelial-mesenchymal transition (EMT) of amnion cells. However, the impact of p38 MAPK in chorion trophoblast cells (CTCs) is unclear. We tested if eliminating p38 will reduce oxidative stress (OS) induced cell fates like cellular senescence, EMT, and inflammation induced by these processes in CTCs.

METHODS

p38MAPK in CTCs was silenced using CRISPR/Cas9. OS was evoked by cigarette smoke extract (CSE) exposure. EMT was evoked by transforming growth factor (TGF)-ß treatment. Cell cycle, senescence, EMT, and inflammation were analyzed.

RESULTS

CSE-induced changes in the cell cycle were not seen in p38KO CTCs compared to WT cells. OS induced by CSE evoked senescence and senescence-associated secretory phenotype (SASP as indicated by IL-6 and IL-8 increase) in WT but not in p38MAPK KO CTCs. No changes were noted in HLA-G expression regardless of the status of p38MAPK. Neither CSE nor TGF-ß evoked EMT in either WT or p38 KO CTCs.

CONCLUSION

Senescence and senescence-associated inflammation in human fetal CTCs are mediated by p38MAPK. Compared to amnion epithelial cells, CTCs are resistant to EMT. This refractoriness may help them to maintain the barrier functions at the choriodecidual interface.

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.

Adapting an organ-on-chip device to study the effect of fetal sex and maternal race/ethnicity on preterm birth related intraamniotic inflammation leading to fetal neuroinflammation

PROBLEM

Fetal neuroinflammation has been linked to preterm birth-related intraamniotic infection and inflammation; However, the contribution of fetal sex and maternal race/ethnicity is unknown. To determine if fetal sex and maternal race/ethnicity influence neuroinflammation, an organ-on-chip (OOC) model were established under normal or pathologic conditions utilizing amniotic fluid.

METHOD OF STUDY

OOC is composed of two-cell culture chambers connected by Type IV collagen-coated microchannels. Human fetal astroglia (SVGp12) and microglia (HMC3) were co-cultured at an 80:20 ratio in the inner chamber. The outer chamber contained amniotic fluid (AF) from male and female fetuses of White Hispanic (WH) and African-American (AA) pregnant women with or without lipopolysaccharide (LPS-100 ng/ml) and incubated for 48 h. Glial migration (brightfield microscopy), activation (Immunocytochemistry), and cytokine production (Luminex assays) were quantified and compared (N = 4 for each category of sex and race/ethnicity).

RESULTS

In a pooled analysis, AF+LPS did not induce glial activation or inflammatory changes compared to AF alone. When stratified by sex, male AF+LPS promoted significant glial activation (high CD11b:p < 0.05; low Iba1:p < 0.01) compared to male AF without LPS; however, this was not associated with changes in pro-inflammatory cytokines. When stratified by race/ethnicity, AF+LPS induced glial activation in both groups, but a differential increase in pro-inflammatory cytokines was seen between WH and AA AF (WH-interleukin-1β: p < 0.05; AA-interleukin-8: p < 0.01).

CONCLUSION

This OOC model of fetal neuroinflammation has determined that race/ethnicity differences do exist for perinatal brain injury. The fetal sex of neonates was not a determining factor of susceptibility to intraamniotic inflammation leading to neuroinflammation.

Stress signaler p38 mitogen-activated kinase activation: a cause for concern?

Oxidative stress (OS) induced activation of p38 mitogen-activated kinase (MAPK) and cell fate from p38 signaling was tested using the human fetal membrane's amnion epithelial cells (AEC). We created p38 KO AEC using the CRISPR/Cas9 approach and tested cell fate in response to OS on an AEC-free fetal membrane extracellular matrix (ECM). Screening using image CyTOF indicated OS causing epithelial-mesenchymal transition (EMT). Further testing revealed p38 deficiency prevented AEC senescence, EMT, cell migration, and inflammation. To functionally validate in vitro findings, fetal membrane-specific conditional KO (cKO) mice were developed by injecting Cre-recombinase encoded exosomes intra-amniotically into p38αloxP/loxP mice. Amnion membranes from p38 cKO mice had reduced senescence, EMT, and increased anti-inflammatory IL-10 compared with WT animals. Our study suggested that overwhelming activation of p38 in response to OS inducing risk exposures can have an adverse impact on cells, cause cell invasion, inflammation, and ECM degradation detrimental to tissue homeostasis.

Irregular Expression of Cellular Stress Response Markers in the Placenta of Women with Chronic Venous Disease

Pregnancy comprises a period in a woman's life in which the circulatory system is subjected to hemodynamical and biochemical changes. During this period, while restructuring blood vessels and exchanging maternal-fetal products there is an increased risk of developing chronic venous disease (CVD), which may have an echo in life after childbirth for both mother and child. Previously, we investigated that pregnancy-associated CVD involves changes in placental architecture at angiogenesis, lymphangiogenesis and villi morphology compared with healthy controls (HC) with no history of CVD. We aimed to more deeply investigate the oxidative stress response in placenta from women with CVD versus HC through several markers (NRF2, KEAP1, CUL3, GSK-3β). An observational, analytical, and prospective cohort study was conducted on 114 women in their third trimester of pregnancy (32 weeks). A total of 62 participants were clinically diagnosed with CVD. In parallel, 52 controls with no history of CVD (HC) were studied. Gene and protein expressions of NRF2, KEAP1, CUL3, GSK-3β were analyzed by real-time polymerase chain reaction (RT-qPCR) and immunohistochemistry. Nrf2 gene and protein expression was significantly greater in placental villi of women with CVD, while Keap1, CUL-3 and GSK-3β gene and protein expressions were significantly lower. Our results defined an aberrant gene and protein expression of Nrf2 and some of their main regulators Keap1, CUL-3 and GSK-3 β in the placenta of women with CVD, which could be an indicator of an oxidative environment observed in this tissue.

Impact of Oxidative Stress on Molecular Mechanisms of Cervical Ripening in Pregnant Women

Uterine cervix is one of the essential factors in labor and maintaining the proper course of pregnancy. During the last days of gestation, the cervix undergoes extensive changes manifested by transformation from a tight and rigid to one that is soft and able to dilate. These changes can be summarized as “cervical ripening”. Changes in the cervical tissue can be referred to as remodeling of the extracellular matrix. The entire process is the result of a close relationship between biochemical and molecular pathways, which is strictly controlled by inflammatory and endocrine factors. When the production of reactive oxygen species exceeds the antioxidant capacity, oxidative stress occurs. A physiologic increase of reactive oxygen species (ROS) and reactive nitrogen species (RNS) is observed through pregnancy. ROS play important roles as second messengers in many intracellular signaling cascades contributing to the course of gestation. This review considers their involvement in the cervical ripening process, emphasizing the molecular and biochemical pathways and the clinical implications.

Glycogen Synthase Kinase 3β inhibits BMSCs Chondrogenesis in Inflammation via the Cross-Reaction between NF-κB and β-Catenin in the Nucleus

Inflammation can influence the pluripotency and self-renewal of mesenchymal stem cells (MSCs), thereby altering their cartilage regeneration ability. Sprague-Dawley (SD) rat bone marrow mesenchymal stem cells (BMSCs) were isolated and found to be defective in differentiation potential in the interleukin-1β- (IL-1β-) induced inflammatory microenvironment. Glycogen synthase kinase-3β (GSK-3β) is an evolutionarily conserved serine/threonine kinase that plays a role in numerous cellular processes. The role of GSK-3β in inflammation may be related to the nuclear factor-κB (NF-κB) signaling pathway and the Wnt/β-catenin signaling pathway, whose mechanism remains unclear. In this study, we found that GSK-3β can inhibit chondrogenesis of IL-1β-impaired BMSCs by disrupting metabolic balance and promoting cell apoptosis. By using the inhibitors LiCl and SN50, we demonstrated that GSK-3β regulates the chondrogenesis via the NF-κB and Wnt/β-catenin signaling pathways and possibly mediates the cross-reaction between NF-κB and β-catenin in the nucleus. Given the molecular mechanisms of GSK-3β in chondrogenic differentiation in inflammation, GSK-3β is a crucial target for the treatment of inflammation-induced cartilage disease.

Epithelial to mesenchymal transition (EMT) of feto-maternal reproductive tissues generates inflammation: a detrimental factor for preterm birth

Human pregnancy is a delicate and complex process where multiorgan interactions between two independent systems, the mother, and her fetus, maintain pregnancy. Intercellular interactions that can define homeostasis at the various cellular level between the two systems allow uninterrupted fetal growth and development until delivery. Interactions are needed for tissue remodeling during pregnancy at both fetal and maternal tissue layers. One of the mechanisms that help tissue remodeling is via cellular transitions where epithelial cells undergo a cyclic transition from epithelial to mesenchymal (EMT) and back from mesenchymal to epithelial (MET). Two major pregnancy-associated tissue systems that use EMT, and MET are the fetal membrane (amniochorion) amnion epithelial layer and cervical epithelial cells and will be reviewed here. EMT is often associated with localized inflammation, and it is a well-balanced process to facilitate tissue remodeling. Cyclic transition processes are important because a terminal state or the static state of EMT can cause accumulation of proinflammatory mesenchymal cells in the matrix regions of these tissues and increase localized inflammation that can cause tissue damage. Interactions that determine homeostasis are often controlled by both endocrine and paracrine mediators. Pregnancy maintenance hormone progesterone and its receptors are critical for maintaining the balance between EMT and MET. Increased intrauterine oxidative stress at term can force a static (terminal) EMT and increase inflammation that are physiologic processes that destabilize homeostasis that maintain pregnancy to promote labor and delivery of the fetus. However, conditions that can produce an untimely increase in EMT and inflammation can be pathologic. These tissue damages are often associated with adverse pregnancy complications such as preterm prelabor rupture of the membranes (pPROM) and spontaneous preterm birth (PTB). Therefore, an understanding of the biomolecular processes that maintain cyclic EMT-MET is critical to reducing the risk of pPROM and PTB. Extracellular vesicles (exosomes of 40-160 nm) that can carry various cargo are involved in cellular transitions as paracrine mediators. Exosomes can carry a variety of biomolecules as cargo. Studies specifically using exosomes from cells undergone EMT can carry a pro-inflammatory cargo and in a paracrine fashion can modify the neighboring tissue environment to cause enhancement of uterine inflammation.

Exosomes from Ureaplasma parvum-infected ectocervical epithelial cells promote feto-maternal interface inflammation but are insufficient to cause preterm delivery

This study determined if exosomes from ectocervical epithelial (ECTO) cells infected with Ureaplasma parvum (U. parvum) can carry bacterial antigens and cause inflammation at the feto-maternal interface using two organ-on-chip devices, one representing the vagina-cervix-decidua and another one mimicking the feto-maternal interface, and whether such inflammation can lead to preterm birth (PTB). Exosomes from U. parvum-infected ECTO cells were characterized using cryo-electron microscopy, nanoparticle tracking analysis, Western blot, and Exoview analysis. The antigenicity of the exosomes from U. parvum-infected ECTO cells was also tested using THP-1 cells and our newly developed vagina-cervix-decidua organ-on-a-chip (VCD-OOC) having six microchannel-interconnected cell culture chambers containing cells from the vagina, ectocervical, endocervical, transformation zone epithelia, cervical stroma, and decidua. The VCD-OOC was linked to the maternal side of our previously developed feto-maternal interface organ-on-a-chip (FMi-OOC). Cell culture media were collected after 48 h to determine the cytokine levels from each cell line via ELISA. For physiological validation of our in vitro data, high-dose exosomes from U. parvum-infected ECTO cells were delivered to the vagina of pregnant CD-1 mice on E15. Mice were monitored for preterm birth (PTB, < E18.5 days). Exosomes from ECTO cells infected with U. parvum (UP ECTO) showed significant downregulation of exosome markers CD9, CD63, and CD81, but contained multiple banded antigen (MBA), a U. parvum virulence factor. Monoculture experiments showed that exosomes from UP ECTO cells delivered MBA from the host cell to uninfected endocervical epithelial cells (ENDO). Moreover, exposure of THP-1 cells to exosomes from UP ECTO cells resulted in increased IL-8 and TNFα and reduced IL-10. The OOC experiments showed that low and high doses of exosomes from UP ECTO cells produced a cell type-specific inflammatory response in the VCD-OOC and FMi-OOC. Specifically, exosomes from UP ECTO cells increased pro-inflammatory cytokines such as GM-CSF, IL-6, and IL-8 in cervical, decidual, chorion trophoblast, and amnion mesenchymal cells. The results from our OOC models were validated in our in vivo mice model. The inflammatory response was insufficient to promote PTB. These results showed the potential use of the VCD-OOC and FMi-OOC in simulating the pathophysiological processes in vivo.

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.

Functional role and regulation of permeability-glycoprotein (P-gp) in the fetal membrane during drug transportation

OBJECTIVE

Na⁺ /H⁺ exchange regulatory factor-1 (NHERF-1) is a class I PDZ (PSD95/Discs-large/ZO-1) binding protein involved in cell-surface expression and stabilization of transporter proteins, including permeability-glycoprotein (P-gp) in various cell types. P-gp, expressed in placental trophoblasts, is an efflux transporter protein that influences the pharmacokinetics of various drugs used during pregnancy. Previously we have reported that NHERF-1 regulates fetal membrane inflammation. However, the role of NHERF-1 in regulating P-gp in the fetal membrane during drug transportation remains unclear. This study determined the interplay between NHERF-1 and P-gp in human fetal membrane cells.

METHODS

Fetal membranes from normal, term cesareans were screened for P-gp by immunohistochemistry (IHC). Chorionic trophoblast (CTC), with the highest expression of P-gp among fetal membrane cells, was further used to test interactive properties between NHERF-1 and P-gp. BeWo (placental trophoblast cell line) cells were used as a control. Immunoprecipitation (IP) of CTC lysates using the P-gp antibody followed by western blot determined co-precipitation of NHERF-1. Silencing NHERF-1 using small interfering RNA further tested the relevance of NHERF-1 in P-gp expression and function in CTC and BeWo cells. NHERF-1 regulation of P-gp's efflux function (drug resistance) was further tested using the ENZO^TM efflux dye kit.

RESULTS

Immunohistochemistry localized, and western blot confirmed P-gp in human fetal membranes, primarily in the CTC with limited expression in the amnion epithelial layer. P-gp expression in the membranes was similar to that seen in the placenta. IP data showed P-gp co-precipitating with NHERF1. Silencing of NHERF-1 resulted in significant drug resistance suggesting P-gp function mediated through NHERF1 in CTCs.

CONCLUSION

Proinflammatory mediator NHERF-1 regulates P-gp and control drug transportation across the fetal membranes. Our data suggest a novel functional role for fetal membranes during pregnancy. Besides the placenta, fetal membranes may also regulate efflux of materials at the feto-maternal interface and control drug transport during pregnancy.

Fetal Membranes Contribute to Drug Transport across the Feto-Maternal Interface Utilizing the Breast Cancer Resistance Protein (BCRP)

During pregnancy, the placenta is established as a primary organ for drug transport at the maternal-fetal interface. The fetal membranes (FM) also form an interface with maternal tissues; however, their role in drug transport has not been previously investigated. Knowledge of drug transport across this feto-maternal interface along with the placenta can improve new drug development and testing for use during pregnancy. We also hypothesize that extracellular vesicles (exosomes 30–160 nm) released from the FM and placental cells may also contain drug transport proteins and might impact drug trafficking across the feto-maternal interfaces. The objectives were to (1) localize the breast cancer resistance protein (BCRP) in human FM; (2) determine the drug transport function of BCRP in chorion trophoblast cells (CTCs) of the FM; and (3) investigate the presence of BCRP in FM cell-derived exosomes, as a paracrine modifier of the tissue environment for transport functions. The gene and protein expressions of ABCG2/BCRP in FMs were determined by quantitative real-time PCR (qRT-PCR) and western blotting (WB) and were localized by immunohistochemistry (IHC). The surface expression of BCRP in FM cells was determined by flow cytometry. The functional role of BCRP was assessed by an EFFLUX dye multidrug resistance assay. The presence of BCRP in exosomes derived from CTCs and BeWo cells was examined using ExoView^®. Data derived from CTCs are compared with placental trophoblast cells (BeWo). BCRP is expressed and localized in the fetal membrane, primarily in the chorion trophoblast cell layer and scarcely in the amnion epithelial layer (AEC), and primarily localized on both AEC and CTC cell surfaces. Efflux assay data showed that FM cells have similar drug resistance activity as BeWo cells, suggesting that FM also have drug transportation capabilities. BeWo- and CTC-derived exosomes expressed limited BCRP protein on the surface, so it was predominantly contained in the exosomal lumen. As far as we are aware, this is the first study to report BCRP expression in fetal membrane cells and as cargo in fetal membrane-derived exosomes. We report that fetal membrane cells are capable of drug transportation. Based on these results, investigational drug trials should include the FM and its exosomes as possible drug transportation routes in pregnancy.

Metabolic Effects of Recombinant Human Growth Hormone Replacement Therapy on Juvenile Patients after Craniopharyngioma Resection

Objective: To investigate the effect of short-term recombinant human growth hormone (rhGH) replacement therapy on metabolic parameters in juvenile patients following craniopharyngioma (CP) resection. Methods. This retrospective study included 42 cases of juvenile patients that had undergone CP resection in the Department of Endocrinology at the Peking Union Medical College Hospital, from April 2013 to August 2020. According to whether they received growth hormone replacement therapy, the patients were divided into either the growth hormone replacement therapy (GHRT) group (30 cases) or the control group (12 cases). Changes in body mass index (BMI), BMI z-score, transaminase activity, fasting blood glucose (FBG) levels, blood lipid profile, and high-sensitivity C-reactive protein (hsCRP) levels were evaluated after one year of GHRT treatment. Results. The average age of the GHRT group was 13.00 (8.00-14.00) years old and these patients had undergone a CP operation an average of 2.00 (1.62-3.15) years earlier. Prior to receiving GHRT treatment, they received appropriate doses of adrenocortical hormone and thyroid hormone replacement therapy. After one year of GHRT treatment, the average BMI z-score decreased from 1.60 ± 1.76 to 1.13 ± 1.73 (P=0.005). Alanine aminotransferase (ALT) activity decreased from 26.50 (17.00∼98.00) U/L to 18.00 (13.00∼26.48) U/L (P ≤ 0.001), and similar changes were observed with regard to aspartate aminotransferase (AST) and glutamyl transferase (GGT) activity in the GHRT treatment group. The average total cholesterol (TC) decreased from 4.67 (4.10-6.14) mmol/L to 4.32 ± 0.85 mmol/L (P=0.002), and low-density lipoprotein (LDL) levels decreased from 3.05 ± 0.95 mmol/L to 2.56 ± 0.65 mmol/L (P=0.001) in the GHRT treatment group. The average blood urea nitrogen level decreased from 4.53 ± 1.09 mmol/L to 3.92 ± 0.82 mmol/L (P=0.016) and the average serum creatinine (SCr) level decreased from 55.59 ± 12.54 µmol/L to 51.15 ± 10.51 µmol/L (P=0.005) in the GHRT treatment group. The average hsCRP level decreased from 3.23 (1.79∼4.34) mg/L to 0.92 (0.42∼1.21) mg/L in the GHRT treatment group. In the control group, the average ALT activity increased from 26.58 ± 8.75 U/L to 42.58 ± 24.59 U/L (P=0.039), GGT activity increased from 19.0 (13.25-29.25) U/L to 25.00 (14.75-34.75) U/L (P=0.026), and LDL levels increased from 2.27 ± 0.76 mmol/L to 3.43 ± 1.28 mmol/L (P=0.04). Conclusion. GHRT treatment improves the metabolic parameters of juvenile patients that have undergone craniopharyngioma resection by reducing BMI z-scores, low-density lipoprotein, and hsCRP levels and improving liver function.

Generation and characterization of human Fetal membrane and Decidual cell lines for reproductive biology experiments†

Human fetal membrane and maternal decidua parietalis form one of the major feto-maternal interfaces during pregnancy. Studies on this feto-maternal interface is limited as several investigators have limited access to the placenta, and experience difficulties to isolate and maintain primary cells. Many cell lines that are currently available do not have the characteristics or properties of their primary cells of origin. Therefore, we created, characterized the immortalized cells from primary isolates from fetal membrane-derived amnion epithelial cells, amnion and chorion mesenchymal cells, chorion trophoblast cells and maternal decidua parietalis cells. Primary cells were isolated from a healthy full-term, not in labor placenta. Primary cells were immortalized using either a HPV16E6E7 retroviral or a SV40T lentiviral system. The immortalized cells were characterized for the morphology, cell type-specific markers, and cell signalling pathway activation. Genomic stability of these cells was tested using RNA seq, karyotyping, and short tandem repeats DNA analysis. Immortalized cells show their characteristic morphology, and express respective epithelial, mesenchymal and decidual markers similar to that of primary cells. Gene expression of immortalized and primary cells were highly correlated (R = 0.798 to R = 0.974). Short tandem repeats DNA analysis showed in the late passage number (>P30) of cell lines matched 84-100% to the early passage number (<P10) of the cell lines revealing there were no genetic drift over the passages. Karyotyping also revealed no chromosomal anomalies. Creation of these cell lines can standardize experimental approaches, eliminate subject to subject variabilities, and benefit the reproductive biological studies on pregnancies by using these cells.

The role of nuclear factor erythroid 2-related factor 2 (NRF2) in normal and pathological pregnancy: A systematic review

OBJECTIVE

A homeostatic balance between reactive oxygen species production and the antioxidant redox system is an important component of normal pregnancy. Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) preserves cellular homeostasis by enhancing the cell's innate antioxidant status to reduce oxidative stress and inflammatory damage to the cell during pregnancy. Active Nrf2, in the nucleus of the cell, transactivates various antioxidant genes. The objective of this systematic review was to synthesize evidence on the role of Nrf2 in various adverse pregnancy outcomes (APOs).

METHODS

We conducted a systematic review of the role of Nrf2 in pregnancy. Articles written in English, Portuguese, and Spanish were obtained from three different databases from inception until January 2021. The titles, abstracts and full text were reviewed independently by six reviewers. The quality of the included studies was assessed using a quality assessment tool developed to assess basic science and clinical studies. Nrf2 expression (gene and protein), functional contributions, and association with APOs were assessed.

RESULTS

A total of 747 citations were identified; 80 were retained for full review. Most studies on Nrf2 have been carried out using placental tissues and placenta-derived cells. Limited studies have been conducted using fetal membranes, uterus, and cervix. Nuclear translocation of Nrf2 results in transactivation of antioxidant enzymes, including glutathione peroxidase, hemeoxygenase-1, and superoxide dismutase in gestational cells during pregnancy. This antioxidant response maintains cellular homeostasis during pregnancy. This promotes trophoblast cell survival and prevents cell death and abnormal angiogenesis in the placenta. Excessive and insufficient Nrf2 response may promote oxidative and reductive stress, respectively. This Nrf2 dysregulation has been associated with APOs including gestational diabetes mellitus, intrauterine growth restriction, reproductive toxicity, preeclampsia, and preterm birth.

CONCLUSION

Several studies have localized and reported an association between Nrf2's differential expression in reproductive tissues and the pathogenesis of APOs. However, a comprehensive functional understanding of Nrf2 in reproductive tissues is still lacking. Nrf2's activation and functions are complex, and therefore, current in vitro and in vivo studies are limited in their experimental approaches. We have identified key areas for future Nrf2 research that is needed to fill knowledge gaps.

Melatonin alleviates hippocampal GR inhibition and depression-like behavior induced by constant light exposure in mice

Light pollution has become a potential health risk factor worldwide. Chronic exposure to constant light (CCL) leads to depressive-like behavior, yet the mechanism remains unclear. In this study, mice exposed to CCL for 3 weeks exhibited depression-like behaviors, with decreased melatonin in plasma and increased oxidative stress in hippocampus. Meanwhile, CCL-exposed mice showed elevated plasma corticosterone (CORT) levels and diminished glucocorticoid receptor (GR) phosphorylation in hippocampus. Concurrently, glycogen synthase kinase 3 beta (GSK3β) was inactivated with increased phosphorylation at Ser9. The interrelationship of GSK3β and GR was clarified in mouse hippocampal neuron (HT-22) cells. GSK3β inhibitor CHIR-99021 induced GR inhibition with diminished phosphorylation, while GR inhibitor RU486 did not affect GSK3β expression or phosphorylation. Furthermore, GSK3β-mediated GR inhibition was reproduced in vitro in HT-22 cells treated with melatonin receptor antagonist luzindole and H2O2 in combination. Finally, melatonin reversed GSK3β-mediated GR inhibition in hippocampus and improved CCL-induced depression-like behavior in mice. These results indicate that CCL induces melatonin deficiency and oxidative stress in hippocampus, which in turn leads to GSK3β-mediated GR inhibition and depression-like behavior in mice.

Extracellular vesicles from maternal uterine cells exposed to risk factors cause fetal inflammatory response

Background

Fetal cell-derived exosomes (extracellular vesicles, 40–160 nm) are communication channels that can signal parturition by inducing inflammatory changes in maternal decidua and myometrium. Little is known about maternal cell-derived exosomes and their functional roles on the fetal side. This study isolated and characterized exosomes from decidual and myometrial cells grown under normal and inflammatory/oxidative stress conditions and determined their impact on fetal membrane cells.

Methods

Decidual and myometrial cells were grown under standard culture conditions (control) or exposed for 48 h to cigarette smoke extract or tumor necrosis factor-α, as proxies for oxidative stress and inflammation, respectively. Exosomes were isolated from media (differential ultra-centrifugation followed by size exclusion chromatography), quantified (nano particle tracking analysis), and characterized in terms of their size and morphology (cryo-electron microscopy), markers (dot blot), and cargo contents (proteomics followed by bioinformatics analysis). Maternal exosomes (10⁹/mL) were used to treat amnion epithelial cells and chorion trophoblast cells for 24 h. The exosome uptake by fetal cells (confocal microscopy) and the cytokine response (enzyme-linked immunosorbent assays for IL-6, IL-10, and TNF-α) was determined.

Results

Exosomes from both decidual and myometrial cells were round and expressed tetraspanins and endosomal sorting complexes required for transport (ESCRT) protein markers. The size and quantity was not different between control and treated cell exosomes. Proteomic analysis identified several common proteins in exosomes, as well as unique proteins based on cell type and treatment. Compared to control exosomes, pro-inflammatory cytokine release was higher in both amnion epithelial cell and chorion trophoblast cell media when the cells had been exposed to exosomes from decidual or myometrial cells treated with either cigarette smoke extract or tumor necrosis factor-α. In chorion trophoblast cells, anti-inflammatory IL-10 was increased by exosomes from both decidual and myometrial cells.

Conclusion

Various pathophysiological conditions cause maternal exosomes to carry inflammatory mediators that can result in cell type dependent fetal inflammatory response.

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.

Extracellular vesicle mediated feto-maternal HMGB1 signaling induces preterm birth

Preterm birth (PTB; <37 weeks of gestation) impacts ∼11% of all pregnancies and contributes to 1 million neonatal deaths worldwide annually. An understanding of the feto-maternal (F-M) signals that initiate birthing (parturition) at term is critical to design strategies to prevent their premature activation, resulting in PTB. Although endocrine and immune cell signaling are well-reported, fetal-derived paracrine signals capable of transitioning quiescent uterus to an active state of labor are poorly studied. Recent reports have suggested that senescence of the fetal amnion membrane coinciding with fetal growth and maturation generates inflammatory signals capable of triggering parturition. This is by increasing the inflammatory load at the feto-maternal interface (FMi) tissues (i.e., amniochorion-decidua). High mobility group box 1 protein (HMGB1), an alarmin, is one of the inflammatory signals released by senescent amnion cells via extracellular vesicles (exosomes; 40-160 nm). Increased levels of HMGB1 in the amniotic fluid, cord and maternal blood are associated with term and PTB. This study tested the hypothesis that senescent amnion cells release HMGB1, which is fetal signaling capable of increasing FMi inflammation, predisposing them to parturition. To test this hypothesis, exosomes from amnion epithelial cells (AECs) grown under normal conditions were engineered to contain HMGB1 by electroporation (eHMGB1). eHMGB1 was characterized (quantity, size, shape, markers and loading efficiency), and its propagation through FMi was tested using a four-chamber microfluidic organ-on-a-chip device (FMi-OOC) that contained four distinct cell types (amnion and chorion mesenchymal, chorion trophoblast and decidual cells) connected through microchannels. eHMGB1 propagated through the fetal cells and matrix to the maternal decidua and increased inflammation (receptor expression [RAGE and TLR4] and cytokines). Furthermore, intra-amniotic injection of eHMGB1 (containing 10 ng) into pregnant CD-1 mice on embryonic day 17 led to PTB. Injecting carboxyfluorescein succinimidyl ester (CFSE)-labeled eHMGB1, we determined in vivo kinetics and report that eHMGB1 trafficking resulting in PTB was associated with increased FMi inflammation. This study determined that fetal exosome mediated paracrine signaling can generate inflammation and induce parturition. Besides, in vivo functional validation of FMi-OOC experiments strengthens the reliability of such devices to test physiologic and pathologic systems.

The Keap1-Nrf2 System: A Mediator between Oxidative Stress and Aging

Oxidative stress, a term that describes the imbalance between oxidants and antioxidants, leads to the disruption of redox signals and causes molecular damage. Increased oxidative stress from diverse sources has been implicated in most senescence-related diseases and in aging itself. The Kelch-like ECH-associated protein 1- (Keap1-) nuclear factor-erythroid 2-related factor 2 (Nrf2) system can be used to monitor oxidative stress; Keap1-Nrf2 is closely associated with aging and controls the transcription of multiple antioxidant enzymes. Simultaneously, Keap1-Nrf2 signaling is also modulated by a more complex regulatory network, including phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), protein kinase C, and mitogen-activated protein kinase. This review presents more information on aging-related molecular mechanisms involving Keap1-Nrf2. Furthermore, we highlight several major signals involved in Nrf2 unbinding from Keap1, including cysteine modification of Keap1 and phosphorylation of Nrf2, PI3K/Akt/glycogen synthase kinase 3β, sequestosome 1, Bach1, and c-Myc. Additionally, we discuss the direct interaction between Keap1-Nrf2 and the mammalian target of rapamycin pathway. In summary, we focus on recent progress in research on the Keap1-Nrf2 system involving oxidative stress and aging, providing an empirical basis for the development of antiaging drugs.

Therapeutic Potential of Reactive Oxygen Species: State of the Art and Recent Advances

In the last decade, several studies have proven that when at low concentration reactive oxygen species (ROS) show an adaptive beneficial effect and posited the idea that they can be utilized as inexpensive and convenient inducers of tissue regeneration. On the other hand, the recent discovery that cancer cells are more sensitive to oxidative damage paved the way for their use in the selective killing of tumor cells, and sensors to monitor ROS production during cancer treatment are under extensive investigation. Nevertheless, although ROS-activated signaling pathways are well established, less is known about the mechanisms underlying the switch from an anabolic to a cytotoxic response. Furthermore, a high variability in biological response is observed between different modalities of administration, cell types, donor ages, eventual concomitant diseases, and external microenvironment. On the other hand, available preclinical studies are scarce, whereas the quest for the most suitable systems for in vivo delivery is still elusive. Furthermore, new strategies to control the temporal pattern of ROS release need to be developed, if considering their tumorigenic potential. This review initially discusses ROS mechanisms of action and their potential application in stem cell biology, tissue engineering, and cancer therapy. It then outlines the state of art of ROS-based drugs and identifies challenges faced in translating ROS research into clinical practice.

Sodium Hydrogen Exchanger Regulatory Factor-1 (NHERF1) Regulates Fetal Membrane Inflammation

The fetal inflammatory response, a key contributor of infection-associated preterm birth (PTB), is mediated by nuclear factor kappa B (NF-kB) activation. Na⁺/H⁺ exchanger regulatory factor-1 (NHERF1) is an adapter protein that can regulate intracellular signal transduction and thus influence NF-kB activation. Accordingly, NHERF1 has been reported to enhance proinflammatory cytokine release and amplify inflammation in a NF-kB-dependent fashion in different cell types. The objective of this study was to examine the role of NHERF1 in regulating fetal membrane inflammation during PTB. We evaluated the levels of NHERF1 in human fetal membranes from term labor (TL), term not in labor (TNIL), and PTB and in a CD1 mouse model of PTB induced by lipopolysaccharide (LPS). Additionally, primary cultures of fetal membrane cells were treated with LPS, and NHERF1 expression and cytokine production were evaluated. Gene silencing methods using small interfering RNA targeting NHERF1 were used to determine the functional relevance of NHERF1 in primary cultures. NHERF1 expression was significantly (p < 0.001) higher in TL and PTB membranes compared to TNIL membranes, and this coincided with enhanced (p < 0.01) interleukin (IL)-6 and IL-8 expression levels. LPS-treated animals delivering PTB had increased levels of NHERF1, IL-6, and IL-8 compared to phosphate-buffered saline (PBS; control) animals. Silencing of NHERF1 expression resulted in a significant reduction in NF-kB activation and IL-6 and IL-8 production as well as increased IL-10 production. In conclusion, downregulation of NHERF1 increased anti-inflammatory IL-10, and reducing NHERF1 expression could be a potential therapeutic strategy to reduce the risk of infection/inflammation associated with PTB.

Stretch, scratch, and stress: Suppressors and supporters of senescence in human fetal membranes

INTRODUCTION

Throughout gestation, amnion membranes undergo mechanical and or physiological stretch, scratch, or stress which is withstood by repairing and remodeling processes to protect the growing fetus. At term, increased oxidative stress (OS) activates p38MAPK, induces senescence, and inflammation contributing to membrane dysfunction to promote labor. However, the signaling initiated by stretch and scratch is still unclear. This study compares the induction of p38MAPK mediated senescence by stretch, scratch, and stress in human amnion epithelial cells (AECs).

METHODS

Primary AECs from term, not-in-labor, fetal membranes were cultured using the following conditions (N = 3); 1) CellFlex chambers with or without 20% biaxial stretch, 2) 8-well coverslips with or without scratch, and 3) cells exposed to cigarette smoke extract (CSE) inducing OS. p38MAPK (Western blot or immunocytochemistry), senescence activation, and inflammation (matrix metalloproteinases 9 [MMP9] activity-ELISA) were determined in cells exposed to various conditions. T-test and One-Way ANOVA was used to assess significance.

RESULTS

Biological membrane extension, mimicked by 20% biaxial stretch of AEC, maintained an epithelial morphology and activated P-p38MAPK (P = 0.02) compared to the non-stretch controls, but did not induce senescence or MMP9 activation. AEC scratches were healed within 40-hrs, which included proliferation, migration, and cellular transitions aided by p38MAPK activation but not senescence. CSE induced OS increased p38MAPK (P = 0.018) activation, senescence (P = 0.019), and MMP9 (P = 0.02).

CONCLUSION

Physiologic stretch and scratch experienced during gestation can cause p38MAPK activation without causing senescence or inflammation. This may be indicative of p38MAPK's role in tissue remodeling during pregnancy. Overwhelming OS, experienced at term, results in P-p38MAPK mediated senescence and inflammation to disrupt membrane remodeling.

Novel Insights into the Regulatory Role of Nuclear Factor (Erythroid-Derived 2)-Like 2 in Oxidative Stress and Inflammation of Human Fetal Membranes

Fetal membrane dysfunction in response to oxidative stress (OS) is associated with adverse pregnancy outcomes. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is one of the regulators of innate OS response. This study evaluated changes in Nrf2 expression and its downstream targets heme oxygenase (HO-1) and peroxisome proliferator-activated receptor gamma (PPARγ) in fetal membranes during OS and infection in vitro. Furthermore, we tested the roles of sulforaphane (SFN; an extract from cruciferous vegetables) and trigonelline (TRN; an aromatic compound in coffee) in regulating Nrf2 and its targets. Fetal membranes (n = 6) collected at term were placed in an organ explant system were treated with water-soluble cigarette smoke extract (CSE), an OS inducer (1:10), and lipopolysaccharide (LPS; 100 ng/mL). Nrf2 expression, expression, its enhancement by sulforaphane (SFN, 10 µM/mL) and down regulation by TRN (10uM/mL) was determined by western blots. Expression of Nrf2 response elements PPARγ (western) heme oxygenase (HO-1), and IL-6 were quantified by ELISA. CSE and LPS treatment of fetal membranes increased nrf2, but reduced HO-1 and PPARγ and increased IL-6. Co-treatment of SFN, but not with TRN, with CSE and LPS increased Nrf2 substantially, as well as increased HO-1 and PPARγ and reduced IL-6 expression. Risk factor-induced Nrf2 increase is insufficient to generate an antioxidant response in fetal membranes. Sulforaphane may enhance innate antioxidant and anti-inflammatory capacity by increasing NRF-2 expression.

Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes

Spontaneous preterm birth (PTB) and preterm pre-labor rupture of the membranes (pPROM) are major pregnancy complications. Although PTB and pPROM have common etiologies, they arise from distinct pathophysiologic pathways. Inflammation is a common underlying mechanism in both conditions. Balanced inflammation is required for fetoplacental growth; however, overwhelming inflammation (physiologic at term and pathologic at preterm) can lead to term and preterm parturition. A lack of effective strategies to control inflammation and reduce the risk of PTB and pPROM suggests that there are several modes of the generation of inflammation which may be dependent on the type of uterine tissue. The avascular fetal membrane (amniochorion), which provides structure, support, and protection to the intrauterine cavity, is one of the key contributors of inflammation. Localized membrane inflammation helps tissue remodeling during pregnancy. Two unique mechanisms that generate balanced inflammation are the progressive development of senescence (aging) and cyclic cellular transitions: epithelial to mesenchymal (EMT) and mesenchymal to epithelial (MET). The intrauterine build-up of oxidative stress at term or in response to risk factors (preterm) can accelerate senescence and promote a terminal state of EMT, resulting in the accumulation of inflammation. Inflammation degrades the matrix and destabilizes membrane function. Inflammatory mediators from damaged membranes are propagated via extracellular vesicles (EV) to maternal uterine tissues and transition quiescent maternal uterine tissues into an active state of labor. Membrane inflammation and its propagation are fetal signals that may promote parturition. This review summarizes the mechanisms of fetal membrane cellular senescence, transitions, and the generation of inflammation that contributes to term and preterm parturitions.

Oxidative Stress in Preterm Infants: Overview of Current Evidence and Future Prospects

Preterm birth (PTB), defined as parturition prior to 37 weeks of gestation, is the leading cause of morbidity and mortality in the neonatal population. The incidence and severity of complications of prematurity increase with decreasing gestational age and birthweight. The aim of this review study is to select the most current evidence on the role of oxidative stress in the onset of preterm complication prevention strategies and treatment options with pre-clinical and clinical trials. We also provide a literature review of primary and secondary studies on the role of oxidative stress in preterm infants and its eventual treatment in prematurity diseases. We conducted a systematic literature search of the Medline (Pubmed), Scholar, and ClinicalTrials.gov databases, retroactively, over a 7-year period. From an initial 777 articles identified, 25 articles were identified that met the inclusion and exclusion criteria. Of these, there were 11 literature reviews: one prospective cohort study, one experimental study, three case-control studies, three pre-clinical trials, and six clinical trials. Several biomarkers were identified as particularly promising, such as the products of the peroxidation of polyunsaturated fatty acids, those of the oxidation of phenylalanine, and the hydroxyl radicals that can attack the DNA chain. Among the most promising drugs, there are those for the prevention of neurological damage, such as melatonin, retinoid lactoferrin, and vitamin E. The microbiome also has an important role in oxidative stress. In conclusion, the most recent studies show that a strong relationship between oxidative stress and prematurity exists and that, unfortunately, there is still little therapeutic evidence reported in the literature.

Exosomal Nrf2: From anti-oxidant and anti-inflammation response to wound healing and tissue regeneration in aged-related diseases

Accumulation of oxidative stress in cells is an essential feature of cellular senescence and aging. This phenomenon is involved in different age-related diseases through dysregulation of homeostasis and impairing repair and regeneration (wound healing) capacity, which can suppress antioxidant responses such as the activity of antioxidant enzymes and damaged protein clearance system. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor which regulates basal and inducible expression pattern of specific genes (antioxidants and detoxifications) through antioxidant element response (ARE) sites in the stress condition, specifically in chronic and age-related stresses. Nrf2 maintains cellular redox hemostasis and promotes rejuvenation. Exosomes are nanoscale vesicles that are released by various cells to actively regulate the complex cellular signaling networks. Exosomal-Nrf2 and exosomal-Nrf2-mediated products can modulate oxidative hemostasis in target cells to induce tissue repairing with therapeutic proposes, and regeneration capability. In this study, we summarized the role of exosomal-Nrf2 in different age-related diseases, including diabetic foot ulcers, atherosclerosis, chronic heart failure, reproductive cell failures, and neurodegenerative diseases. In addition, we briefly explained the crosstalk between plant exosomes and mammalian cell metabolism in the benefit of cellular stress suppression.

Changes in mediators of pro-cell growth, senescence, and inflammation during murine gestation

PROBLEM

Senescence of the fetal membranes and senescence-associated inflammation have been associated with parturition at term and pre-term in both mice and humans. Using a pregnant mouse model, we determined changes in multiple molecular signalers contributing to senescence and inflammation associated with parturition.

METHOD OF STUDY

Fetal membranes were collected from timed-pregnant CD-1 mice on gestation days (E) 13, 15, 17, 18, and 19. Immunohistochemistry (IHC) localized pro-cell growth factors glycogen synthase kinase 3β (GSK3β) and β-catenin. Gestational age-associated changes in pro-cell growth vs senescence mediators (p38 mitogen-activated protein kinase [p38MAPK]), prooxidants (heme oxygenase-1 [HO-1], peroxisome proliferator-activated receptor γ [PPARγ]), and pro- and anti-inflammatory cytokines (IL-6, IL-8, IL-10, and IL-1β) were determined by Western blots and Luminex assays.

RESULTS

Fetal membrane expressions of phosphorylated forms of GSK3β (inactivation) and p38MAPK (activation) increased, while β-catenin expression decreased, as gestation progressed. Antioxidant HO-1 expression decreased while PPARγ increased toward term gestation. IL-6 and IL-8 concentrations were highest on E19 (day of delivery), while IL-10 and IL-1β concentrations were highest on E15.

CONCLUSION

Mouse fetal membranes showed a progressive senescence marker increase coincided with downregulation of cell growth factors. Development of senescence is associated with inflammation. Senescence-associated changes are natural and physiologic and indicative of fetal membranes' readiness for parturition.