Homeobox genes for embryo implantation: From mouse to human

The proper development of uterus to a state of receptivity and the attainment of implantation competency for blastocyst are 2 indispensable aspects for implantation,which is considered to be a critical event for successful pregnancy. Like many developmental processes, a large number of transcription factors, such as homeobox genes, have been shown to orchestrate this complicated but highly organized physiological process during implantation. In this review, we focus on progress in studies of the role of homeobox genes, especially the Hox and Msx gene families, during implantation, together with subsequent development of post-implantation uterus and related reproductive defects in both mouse models and humans, that have led to better understanding of how implantation is precisely regulated and provide new insights into infertility.

Molecular Mechanisms Underlying Cell-Fate Specification and Cellular Diversity of the Trophoblast Lineage during Placental Morphogenesis in Mice

Placental morphogenesis is a highly dynamic process involving mutual recognition and interlacing between the trophoblast-uterus and ultimately the initiation of the maternal-fetal circulatory system.During placental morphogenesis in mice,the trophoblast lineage,which integrates maternal and fetal signaling,undergoes stage-specific changes in gene regulatory programs directing cellular proliferation and fate specification,generating diverse trophoblast subtypes.While accumulating evidence from studies on genetically engineered and mutant mice has revealed the involvement of cell-specific core transcription factors in certain key events during placental morphogenesis,the precise molecular mechanisms by which multipotent trophoblasts gradually differentiate into different subtypes are still largely unknown.In this review,we primarily focus on mutant mouse models with placental phenotypes to provide a comprehensive understanding of the molecular mechanisms underlying cell-fate specification and cellular diversity of the trophoblast lineage during the placental morphogenesis.

Family socioeconomic position and abnormal birth weight:evidence from a Chinese birth cohort

Background Birth weight is a strong determinant of infant short-and long-term health outcomes.Family socioeconomic position(SEP)is usually positively associated with birth weight.Whether this association extends to abnormal birth weight or there exists potential mediator is unclear.Methods We analyzed data from 14,984 mother-infant dyads from the Born in Guangzhou Cohort Study.We used multi-variable logistic regression to assess the associations of a composite family SEP score quartile with macrosomia and low birth weight(LBW),and examined the potential mediation effect of maternal pre-pregnancy body mass index(BMI)using causal mediation analysis.Results The prevalence of macrosomia and LBW was 2.62%(n=392)and 4.26%(n=638).Higher family SEP was associated with a higher risk of macrosomia(OR 1.30,95%CI 0.93-1.82;OR 1.53,95%CI 1.11-2.11;and OR 1.59,95%CI 1.15-2.20 for the 2nd,3rd,and 4th SEP quartile respectively)and a lower risk of LBW(OR 0.69,95%CI 0.55-0.86;OR 0.76,95%CI 0.61-0.94;and OR 0.61,95%CI 0.48-0.77 for the 2nd,3rd,and 4th SEP quartile respectively),compared to the 1st SEP quartile.We found that pre-pregnancy BMI did not mediate the associations of SEP with macrosomia and LBW.Conclusions Socioeconomic disparities in fetal macrosomia and LBW exist in Southern China.Whether the results can be applied to other populations should be further investigated.

Effect of Growth Temperature on Carbon Nanotube Grafting Morphology and Mechanical Behavior of Carbon Fibers and Carbon] Carbon Composites

High-purity carbon nanotubes （CNTs） with different orientation and lengths were grafted on carbon fibers （CFs） in woven fabrics by using double injection chemical vapor deposition and adjusting the growth temperature. Scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and Raman investigations reveal that the grafted CNTs change from being predominantly aligned and uniform in di- ameter to absolutely disordered and variable in diameter, whilst they show significantly increased crystallinity, as the growth temperature is increased from 730 ~C to 870 ~C. In tensile tests of fiber bundles, much more strength degradation of CFs was observed after the growth process at higher temperature than that at lower temperature. These hybrid preforms produced at different growth temperatures were used to reinforce carbon/carbon （C/C） composites. An increment of 34.4% in out-of-plane compressive strength （OCS） was obtained for the composites containing CNTs grown at 730℃, while the OCS increment exhibits an obvious decrease with increasing the growth temperature. Compared with the higher growth temperature, the lower temperature contributes to the decrease in the strength loss of reinforcing fibers and meanwhile the growth of large extending length of CNTs, which can provide long reinforcement to the pyrocarbon matrix, and thus increase the compressive strength better.

In Vitro Biocompatibility of MC3T3-E1 Osteoblast-like Cells on Arg-Gly-Asp Acid Peptides Immobilized Graphite-like Carbon Coating on Carbon/Carbon Composites

Carbon/carbon （C/C） composites were deposited with graphite-like carbon （GLC） coating, and then, Arg-Gly- Asp acid （RGD） peptides were successfully immobilized onto the functionalized GLC coating. GLC coating was utilized to prevent carbon particles releasing and create a uniform surface condition for C/C composites. RGD peptides were utilized to improve biocompatibility of GLC coating. Surface chemical characterizations of functionalized GLC coating were detected by contact angle measurement, X-ray photoelectron spectroscopy and Raman spectra. Optical morphology of GLC coatings was observed by confocal laser scanning microscopy. In vitro biological performance was determined using samples seeded with MC3T3-E1 osteoblast-like cells and cultured for 1 week. Surface characterizations and morphological analysis indicated that C/C composites were covered by a dense and uniform GLC coating. Contact angle of GLC coating was reduced to 27.2° when it was functionalized by H202 oxidation at 40 ℃ for 1 h. In vitro cytological test showed that the RGD peptides immobilized GLC coating had a significant improvement in biocompatibility. It was suggested that RGD peptides provided GLC coating with a bioactive surface to improve cell adhesion and proliferation on C/C composites.

Frontier Progress in the Establishment of Trophoblast Stem Cell and the Identification of New Cell Subtypes at the Maternal-Fetal Interface

Proper development of the human placenta is of vital importance for a successful pregnancy,and a series of pregnancy complications are considered originating from dysfunctional placentas.Like other organ system development,placentation requires large numbers of co-regulators,while the underlying molecular mechanisms orchestrating the placental formation and function are poorly understood.Although we have made many signs of progress in understanding the placental architectures and developments using mouse models,the species-specific differences impede our progress due to the lack of appropriate model systems.In the past few years,major progress has been made by the establishment of novel in-vitro self-renewing stem cell models,as well as identifying the full picture of the cellular organization of the maternal and fetal interface.Providing the tools for the investigation of placentation and reproductive-related regulation mechanism.In this review,we focus on the detailed progress of the human trophoblast stem cells culturing system,and the cellular and molecular terrain at the maternal-fetal interface,respectively,thus providing new insights into placental development.