Stromal cell decidualization and embryo implantation: a vulnerable step leading to successful pregnancy

Endometrial stromal cell decidualization is a crucial step in endometrial remodeling during pregnancy.Decidualization is controlled by orchestrated ovarian hormones,followed by the activation of various downstream signaling pathways.Accumulating evidence has shown multiple functions of decidualized endometrial stromal cells during embryo implantation,including tissue remodeling,antioxidative stress,angiogenesis,and immune tolerance.The distinct secretomes of decidualized stromal cells also reveal their intensive interactions with epithelial,endothelial,and immune cells.However,aberrant decidualization leads to pregnancy failures,such as recurrent pregnancy loss and repeated implantation failure.This review aimed to provide an overview of the molecular mechanisms underlying the divergent functions of decidualized endometrial stromal cells and their potential clinical applications.Moreover,the use of single-cell RNA sequencing data further enhances our understanding of these biological processes.This review discusses decidualization-related signaling pathways that serve as potential therapeutic targets for treating implantation failure in in vitro fertilization and provides novel approaches to investigate the underlying causes of female infertility.

Research Progress on Human Endometrium Decidualization In vitro Cell Models

Decidualization is a special type of differentiation of endometrial stromal cells into secretory decidualized cells,which is closely related to the occurrence of menstruation and establishment of pregnancy.Decidualization abnormalities can cause female infertility and abortion,and the decidualization modelin vitro is an important tool for studying relevant mechanisms.This article summarizes severalin vitro decidualization models in recent research from three aspects,including the selection of model cells and culture systems,evaluation of decidualization markers,and induction schemes.These models can be appropriately selected and applied in specific endometrium-related disease models,such as endometriosis,recurrent pregnancy loss,and preeclampsia.

Unique and independent role of the GABAB1 subunit in embryo implantation and uterine decidualization in mice

Embryo implantation and decidualization are crucial for successful pregnancy,which include multiple genes and signaling pathways,while the precise mechanism regarding embryo implantation and decidualization has yet to be explored.The GABA which activates GABA_(A)or GABA_(B)receptors has been found playing an important role in early pregnancy.Here we seek to investigate whether GABA_(B)receptors participate in embryo implantation in mice.This study first characterized the spatiotemporal expression pattern of GABA_(B)receptors in the uterus during the peri-implantation period and found that GABA_(B1)expression was drastically upregulated in stromal cells on days 4e6,a period of embryo implantation and early stages of decidualization.Embryo delayed implantation and oil-induced decidualization models were further used to confirm that the GABA_(B1)was associated with embryo implantation and decidualization.We also found estrogen or progesterone had no directly effect on expression of GABA_(B1)in ovariectomized model.Because we were unable to detect significant GABA_(B2)which couples with GABA_(B1)to form whole GABA_(B)receptors,and the agonist and antagonist of whole GABA_(B)receptors had weak effect on the proliferation and differentiation of stromal cells as well,we excluded the possibility whole GABA_(B)receptors function,and concluded it should be non-classical signals of GABA_(B1)involving in embryo implantation and decidualization.Future studies should focus on investigating the roles and mechanisms of GABA_(B1)during embryo implantation and decidualization.

Decidualization and Related Pregnancy Complications

Decidualization is the differentiation of endometrial stromal cells into secretory decidual stromal cells.Human decidualization involves some amount of signaling molecules and pathways as well as genetic reprogramming,which is driven by the postovulatory rise in progesterone levels and local cyclic adenosine monophosphate production.Decidualization extends from the primary decidual zone to the secondary decidual zone,and then exits through apoptosis.Evidences support that decidual fibroblasts function as the pool of decidual stromal cells during pregnancy.Decidualization undergoes an acute inflammatory phase,an anti-inflammatory secretory phase to the final recession phase.The decidualization of the inner layer of endometrium,termed decidua,is the most critical determinant of pregnancy success,which can promote placenta formation,modulate immune tolerance,foster resistance to oxidative stress,sense embryo quality,and control labor.Failure to adequate decidualization in terms of hormones,biochemistry,and immunology leads to adverse pregnancy outcomes,including diseases such as preeclampsia,miscarriage,premature labor,repeated implantation failures,and some age-related decline in reproductive capacity.The development of animal models and in vitro culture systems combined with emerging technologies provides a powerful system to explore the mechanism of decidualization.However,decidualization is a dynamic,multi-step process,and translating of current research progress into disease predictions and interventions for pregnancy complications remains to be achieved.The study of periodic regeneration and spontaneous decidualization of the endometrium will be beneficial to the diagnosis and treatment of pregnancy diseases.

Evaluation of the Effectiveness and Safety of One-Time Endodontics in the Treatment of Chronic Apical Periodontitis with Sinus Tract in Pediatric Deciduous Teeth

Objective:To observe the effectiveness and safety of one-time endodontics in the treatment of chronic apical periodontitis with sinus tract in pediatric deciduous teeth.Methods:109 cases of children with chronic apical periodontitis with sinus tract in the deciduous teeth treated in our hospital from January 2022 to December 2023 were selected and grouped by the randomized numerical table method,with 54 cases in the experimental group and 55 cases in the control group.The experimental group was treated with one-time endodontics and the control group was treated with conventional endodontics.Results:After the treatment,the total effective rate of treatment was higher in the experimental group than in the control group(P<0.05);the incidence of adverse events was lower in the experimental group than in the control group(P<0.05);the satisfaction of the children's family members was higher in the experimental group than in the control group(P<0.05);the pain duration was lower in the experimental group than in the control group(P<0.05).Conclusion:In the experimental group,children with chronic apical periodontitis with sinus tract of the deciduous teeth were given one-time endodontic treatment,and the results of its implementation were relatively good.

Tree sapling vitality and recovery following the unprecedented 2018 drought in central Europe

Background:Ongoing climate change is anticipated to increase the frequency and intensity of drought events,thereby affecting forest recovery dynamics and elevating tree mortality.The drought of 2018,with its exceptional intensity and duration,had a significant adverse impact on tree species throughout Central Europe.However,our understanding of the resistance to and recovery of young trees from drought stress remains limited.Here,we examined the recovery patterns of native deciduous tree sapling species following the 2018 drought,and explored the impact of soil depth,understory vegetation,and litter cover on this recovery.Methods:A total of 1,149 saplings of seven deciduous tree species were monitored in the understory of old-growth forests in Northern Bavaria,Central Germany.The vitality of the saplings was recorded from 2018 to 2021 on 170 plots.Results:Fagus sylvatica was the most drought-resistant species,followed by Betula pendula,Acer pseudoplatanus,Quercus spp.,Corylus avellana,Carpinus betulus,and Sorbus aucuparia.Although the drought conditions persisted one year later,all species recovered significantly from the 2018 drought,albeit with a slight decrease in vitality by 2021.In 2018,the drought exhibited a more pronounced adverse effect on saplings in deciduous forests compared to mixed and coniferous forests.Conversely,sapling recovery in coniferous and mixed forests exceeded that observed in deciduous forests in 2019.The pivotal factors influencing sapling resilience to drought were forest types,soil depth,and understory vegetation,whereas litter and forest canopy cover had a negative impact.Conclusion:Long-term responses of tree species to drought can be best discerned through continuous health monitoring.These findings demonstrate the natural regeneration potential of deciduous species in the context of climate change.Selective tree species planting,soil management practices,and promoting understory diversity should be considered when implementing adaptive management strategies to enhance forest resilience to drought events.

Do forest health threats affect upland oak regeneration and recruitment?Advance reproduction is a key co-morbidity

We analyzed national forest inventory data collected from circa 2000–2018 across 37 states in the eastern United States to better understand the influence of forest health related canopy disturbances on the regeneration and recruitment dynamics of upland oaks(Quercus).We found low levels of oak recruitment across all disturbance types examined but limited evidence of any direct effects from the type of disturbance on the population of regenerating oaks.The general lack of differences in oak regeneration response between forest health disturbances and disturbances caused by harvested or non-disturbed plots does not indicate that the effects of forest health disturbances were benign,however.Instead,low level of oak recruitment across all disturbance types highlights the pervasiveness of the trend of shifting composition in once oak-dominated forests where oak is absent or sparse in the regeneration layer.Our results show that oak recruitment was higher when oak was present as advance reproduction prior to disturbance from any cause examined.Collectively,these results lead us to conclude that the widespread inadequacy of oak advance reproduction in mature oak-dominated forests is the prevailing threat to oak forest health and sustainability.We suggest the status of advance reproduction be treated as a co-morbidity when weighing the risk and potential outcomes from other threats to upland oak forests in the eastern United States.

Soil functional indicators in mixed beech forests are clearly species-specifi c

Beech stands are considered part of the ancient forest ecosystems in the northern hemisphere.In mixed stands in beach forest ecosystems,the type of associated tree species can signifi cantly aff ect soil functions,but their infl uence on microbial activity,nutrient cycling and belowground properties is unknown.Here,we considered forest patches in northern Iran that are dominated by diff erent tree species:Fagus orientalis Lipsky,Quercus castaneifolia C.A.Mey.,Pterocarya fraxinifolia(Lam.),Tilia begonifolia Stev.,Zelkova carpinifolia Dippe,Acer cappadocicum Gled,Acer velutinum Boiss.,Fraxinus excelsior L.,Carpinus betulus L.,and Alnus subcordata C.A.Mey.For each forest patch–tree species,litter and soil samples(25×25×10 cm,100 of each)were analyzed for determine soil and litter properties and their relationship with tree species.The litter decomposition rate during a 1-year experiment was also determined.A PCA showed a clear diff erence between selected litter and soil characteristics among tree species.F.orientalis,Q.castaneifolia,P.fraxinifolia,T.begonifolia,Z.carpinifolia,A.cappadocicum,and A.velutinum enhanced soil microbial biomass of carbon,whereas patches with F.excelsior,C.betulus and A.subcordata had faster litter decomposition and enhanced biotic activities and C and N dynamics.Thus,soil function indicators were species-specifi c in the mixed beech forest.A.subcordata(a N-fi xing species),C.betulus and F.excelsior were main drivers of microbial activities related to nutrient cycling in the old-growth beech forest.

Impacts of canopy structure on the sub-canopy solar radiation under a deciduous forest based on fisheye photographs

Forest canopy in a deciduous forest has significant sheltering effects on the sub-canopy solar radiation,significantly influencing the energy balance of snow and permafrost beneath the forest and their spatial distribution.This study employs a digital camera mounted with a fisheye lens to acquire photographs at various times in a growth cycle of the forest canopy at three selected sites in a deciduous forest near the Greater Khingan Mountains Forest Ecological Station,Northeast China.The vegetation types and conditions at the selected sites include P1 in Ledum-Claopodium-L.dahurica,P2 in Carex tato-L.dahurica,and P3 in Betula fruticosa-L.dahurica.After necessary image processing,these photographs were used to identify the canopy structure and its impacts on the sub-canopy solar radiation.Results show that fisheye photographs can successfully capture the forest canopy structure and are useful in estimating the sub-canopy solar radiation.The order of sheltering effects from the largest to the smallest on sub-canopy solar radiation at three selected sites is P3,P1,and P2,highly depending on the canopy density.Then sub-canopy solar radiation was calculated using fisheye photographs and an algorithm validated by in-situ observed solar radiation beneath the canopy at P1 and P3.The results are reasonable,although the accuracy seems compromised due to the mismatch of conditions for calculation and observation.Results also show that the mean annual solar radiation above the canopy was about 148.3 W/m2 in 2018,and the mean annual solar radiation values beneath the canopy were about 90.0,123.8,and 61.0 W/m2 at P1,P2,and P3,with only 60%,84%,and 42%of the total solar radiation penetrating through the canopy,respectively.Even in winter,when the trees are leafless,the canopy sheltering effects cannot be ignored in dense forests.Despite the limitations,fisheye photographs and related algorithms are useful in investigating the forest canopy structure and its impacts on sub-canopy solar radiation.

Extraction of Cinnamomum longepaniculatum deciduous leaves essential oil using solvent-free microwave extraction: Process optimization and quality evaluation

The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.

Exosome-derived miR-146a-5p from decidual macrophages in preeclampsia inhibits the viability and invasive ability of trophoblast cells by targeting HIF1α

Objective:To investigate the effect of exosomes secreted by decidual macrophages on trophoblast cells and their molecular mechanism.Methods:The decidual tissues of patients with preeclampsia(PE)and normal-term pregnant women were collected.Macrophages were obtained by the density gradient method and then flow cell sorting,then the exosomes were extracted.The structure of the exosomes was observed by transmission electron microscope.The expression of CD63,a marker protein of the exocrine body,was detected by western blot,and the exosomes were identified.CCK-8 was used to detect the effect of exosomes on trophoblast cell viability.Transwell migration experiment was used to detect the influence on migration ability.The expression of miR-146a-5p in exosomes was detected by qPCR.The effect of exosomes on the expression of HIF1αprotein in trophoblasts was detected by western blot and detection of the binding site between miR-146a-5p and HIF1αby double luciferase reporter gene was conducted.Results:The exosomes of macrophages present a"cake"structure with a middle depression about 30-130 nm in diameter,and CD63 is highly expressed,which conforms to the characteristics of exosomes.Compared with the normal group,the exosomes of decidual macrophages in the PE group inhibited the activity and migration of trophoblast cells(P<0.001).The expression of miR-146a-5p in the exosomes of decidual macrophages in the PE decreased significantly,and after exosomes of PE decidual macrophages treating trophoblast cells,the protein expression of HIF1αin trophoblast cells was significantly increased.There are targeted binding sites between miR-146a-5p and HIF1α.Conclusion:PE decidual macrophage exosomes can inhibit the viability and migration of trophoblast cells,which may be related to the decreased expression of miR-146a-5p in exosomes,thus promoting HIF1αprotein expression of trophoblast cells.

落叶果树需冷量及其估算模型研究进展

落叶果树的需冷量得到满足,才能顺利完成自然休眠,进行下一个生长发育循环(尤其是正常开花结果),否则其他环境条件再适宜,果树也不萌芽开花,即使萌芽也不整齐,生长结果不良,达不到促成栽培的目的[1].因此,对落叶果树需冷量及其估算的研究至关重要,成为落叶果树设施栽培成败的关键.本文仅就需冷量估算模型进行介绍,以期为设施栽培和更完善的需冷量估算提供理论依据.……

田林老山中山两类森林凋落物研究

田林老山中山两类森林凋落物研究梁宏温（广西农学院林学分院，南宁５３０００１）ＳｔｕｄｉｅｓｏｎｔｈｅＬｉｔｔｅｒｆａｌｌｏｆＴｗｏＦｏｒｅｓｔＴｙｐｃｓｉｎＭｉｄ—ＡｌｔｉｔｕｄｅｏｆＬａｏｓｈａｎＭｏｕｎｔａｉｎｉｎＴｉａｎｌｉｎＣｏｕｎｔｙ．￥Ｌ...

Activation of Uterine Smad3 Pathway Is Crucial for Embryo Implantation

Embryo implantation is a complicated physiological process tightly regulated by multiple biological molecules including growth factors.Transforming growth factor-betas(TGF-βs)and their most specific signal transduction factors,Smads,are expressed in the endometrium during the window of implantation.Recent researches indicated that Smad dependent TGF-β signaling may play an important role in the process of embryo implantation.In this study,we measured the expression of TGF-β1,TGF-β receptor type I(TpRI),Smad3 and p-Smad3 in the endometrium of mice and observed their elevation on day 4,5 and 6 of pseudopregnancy.Then we administrated a specific Smad3 inhibitor(Sis3)into the uterine cavity of mice on day 3 of pregnancy.The results showed a reduction in insulin-like growth factor-1(IGFBP-1)expression and the decreased number of implanted embryo after the administration.In addition,Sis3 was found to reduce the IGFBP-1 secretion in decidualized endometrial stromal cells.Taken all together,our findings demonstrated that TGF-β/Smad3 signaling is involved in the process of embryo implantation.

Transforming growth factor β signaling in uterine development and function

Transforming growth factor β （TGFβ） superfamily is evolutionarily conserved and plays fundamental roles in cell growth and differentiation. Mounting evidence supports its important role in female reproduction and development. TGFBs1-3 are founding members of this growth factor family, however, the in vivo function of TGFβ signaling in the uterus remains poorly defined. By drawing on mouse and human studies as a main source, this review focuses on the recent progress on understanding TGFβ signaling in the uterus. The review also considers the involvement of dysregulated TGFβ signaling in pathological conditions that cause pregnancy loss and fertility problems in women.

Stimulation of decidua development by transplantation of endometrial stem cells

On all terms of pregnancy, insolvency of decidual reaction of endometrial cells is one of the reasons of miscarriages and fetal growth delay. The insufficient decidualization of endometrum leads to infertility in such pathologies, as Asherman’s syndrome and an endometrium atrophy. However, there are data on successful application of autologous bone marrow MSCs for Asherman’s syndrome treatment. The aim of this work was to assay the effect of endometrial mesenchymal stem cell (eMSC) transplantation for decidualization process in pseudopregnant rat. Our study showed that injection of human eMSC suspension into the uterine lumen of pseudopregnant rats facilitated more intensive development of decidua in comparison with phosphate buffed saline (PBS) injection in the control uterine horn. Histological analysis of decidua sections did not reveal any alterations in cell differentiation or tissue structure. In conclusion, we demonstrated for the first time that eMSC transplantation assists the development of all decidual tissue elements. It opens the possibility that eMSCs may be applied for cell therapy of infertility associated with decidualzation insufficiency.

Transplantation of stem cells from human exfoliated deciduous teeth for bone regeneration in the dog mandibular defect

AIM: To investigate the effect of stem cells from human exfoliated deciduous teeth(SHED) transplanted for bone regeneration in the dog mandibular defect.METHODS: In this prospective comparative study, SHEDs had been isolated 5 years ago from human exfoliated deciduous teeth. The undifferentiated stem cells were seeded into mandibular bone through-andthrough defects of 4 dogs. Similar defects in control group were filled with cell-free collagen scaffold. After 12 wk, biopsies were taken and morphometric analysis was performed. The percentage of new bone formation and foreign body reaction were measured in each case. The data were subject to statistical analysis using the Mann-Whitney U and Kruskalwalis statistical tests. Differences at P < 0.05 was considered as significant level.RESULTS: There were no significant differences between control and SHED-seeded groups in connective tissue(P = 0.248), woven bone(P = 0.248) and compact bone(P = 0.082). There were not any side effects in transplanted SHED group such as teratoma or malignancy and abnormalities in this period.CONCLUSION: SHEDs which had been isolated and characterized 5 years ago and stored with cryopreservation banking were capable of proliferation and osteogenesis after 5 years, and no immune response was observed after three months of seeded SHEDs.

Assessing the concentration and potential health risk of heavy metals in China's main deciduous fruits

To assess levels of contamination and human health risk, we analyzed the concentrations of the heavy metals lead （Pb）, cadmium （Cd）, chromium （Cr）, and nickel （Ni） in China’s main deciduous fruits-apple, pear, peach, grape, and jujube. The concentration order of the heavy metals was Ni〉Cr〉Pb〉Cd. In 97.5% of the samples, heavy metal concentrations were within the maximum permissible limits. Among the fruits studied, the heavy metal concentrations in jujube and peach proved to be the highest, and those in grape proved to be the lowest. Only 2.2% of the samples were poluted by Ni, only 0.4% of the samples were poluted by Pb, and no samples were poluted by Cd or Cr. Compared with the other fruits, the combined heavy metal polution was signiifcantly higher （P〈0.05） in peach and signiifcantly lower （P〈0.05） in grape. For the combined heavy metal polution, 96.9% of the samples were at safe level, 2.32% at warning level, 0.65% at light level, and 0.13% at moderate level. In the fruits studied, the contribution of heavy metals to the daily intake rates （DIR） folowed the order of Ni〉Cr〉Pb〉Cd. The highest DIR came from apple, while the lowest DIR came from grape. For each of the heavy metals, the total DIR from ifve studied fruits corresponded to no more than 1.1% of the tolerable daily intake, indicating that no signiifcant adverse health effects are expected from the heavy metals and the fruits studied. The target hazard quotients and the total target hazard quotients demonstrated that none of the analyzed heavy metals may pose risk to consumers through the fruits studied. The highest risk was posed by apple, folowed in decreasing order by peach and pear, jujube, and grape. We suggest that the main deciduous fruits （apple, pear, peach, grape, and jujube） of China’s main producing areas are safe to eat.

Effect of nitrogen levels on photosynthetic parameters,morphological and chemical characters of saplings and trees in a temperate forest

Exploring the response differences of leaf physiology parameters to enhanced nitrogen deposition between saplings and trees is vital for predicting the variations of terrestrial ecosystem structure and function under future global climate change. In this study, the ecophysiological parameters of saplings and trees of Fraxinus mandshurica Rupr. were measured at different levels of nitrogen addition in a temperate forest. The results show that ecophysiological parameters maximum net photosynthetic rate(Pmax), apparent quantum efficiency(a), dark respiration(Rd), light saturation point(Lsp), photosynthetic nitrogen use efficiency(PNUE),specific leaf area(SLA)and stomatal conductance under saturated light intensity(Gsmax) were higher in saplings than in trees. These physiological parameters and not Nleaf(leaf nitrogen content)led to relatively lower Pmaxand Rdin trees. For both saplings and trees, low and median nitrogen addition(23 and 46 kg ha-1a-1) resulted in significant increases in Pmax, Rd, Lsp, Chl, PNUE, SLA and Gsmax. These parameters tended to decline under high additions of nitrogen(69 kg ha-1a-1),whereas Nleaf was always enhanced with increasing nitrogen. Variations in Pmax and Rd with increasing nitrogen were attributed to variations in the strongly related parameters of, Lsp, Chl, PNUE, SLA and Gsmax. Overall, the response sensitivity of physiological parameters to enhanced nitrogen levels was lower in trees compared with saplings.

Do vegetative and reproductive phenophases of deciduous tropical species respond similarly to rainfall pulses?

Deciduous trees with high-density wood that occur in dry seasonal tropical regions respond to rainfall seasonality with synchrony in phenophases. However, they may exhibit interannual differences in synchrony and intensity of phenophases, as strategy for large variations in duration and intensity of rainfall pulses. Nevertheless, it remains unknown how phenophases of deciduous trees of the Brazilian semi-arid region respond to rainfall variations. The phenology of Cordia oncocalyx was monitored in deciduous thorny woodland （Caatinga）, from April 2009 to March 2011, and was correlated with rainfall, soil humidity, temperature, and photoperiod. The rainy years 2009 and 2011 exhibited higher duration of rainfall pulses and lower frequency of interpulses, but in 2010 pulse duration and total rainfall were lower. Circular statistics showed leaf flush followed by flowering and fruiting in the rainy season, and leaf fall and seed dispersal in the dry season.