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Background: The cell development atlas of transition stage from late Carnegie to fetal development (7–9 weeks) remain unclear. It can be seen that the early period of human embryos (7–9 weeks) is a critical research gap. Therefore, we employed single‑cell RNA sequencing to identify cell types and elucidate differentiation relationships. Results: The single‑cell RNA sequencing analysis determines eighteen cell clusters in human embryos during the 7–9 weeks period. We uncover two distinct pathways of cellular development and differentiation. Initially, mesenchymal progenitor cells differentiated into osteoblast progenitor cells and neural stem cells, respectively. Neural stem cells further differentiated into neurons. Alternatively, multipotential stem cells differentiated into adipocyte, hematopoietic stem cells and neutrophil, respectively. Additionally, COL1A2-(ITGA1 + ITGB1) mediated the cell communication between mesenchymal progenitor cells and osteoblast progenitor cells. NCAM1-FGFR1 facilitated the cell communication between mesenchymal progenitor cells and neural stem cells. Notably, NCAM1-NCAM1 as a major contributor mediated the cell communication between neural stem cells and neurons. Moreover, CGA-FSHR simultaneously mediated the communication between multipotential stem cells, adipocyte, hematopoietic stem cells and neutrophil. Distinct cell clusters activated specific transcription factors such as HIC1, LMX1B, TWIST1, and et al., which were responsible for their specific functions. These coregulators, such as HOXB13, VSX2, PAX5, and et al., may mediate cell development and differentiation in human embryos. Conclusions: We provide the cell development atlas for human embryos (7–9 weeks). Two distinct cell development and differentiation pathways are revealed. [ABSTRACT FROM AUTHOR]

BackgroundPregnancy outcome in patients with poor ovarian response (POR) has always been one of the difficult problems in reproductive medicine, but there is few threshold effect analysis of influence of age on live birth rate in POR patients treated by assisted reproductive technology (ART) .ObjectiveTo analyze the threshold effect of influence of age on live birth rate in POR patients treated by ART.MethodsAmong 19 185 women who received routine in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) and embryo transplantation in Department of Gynaecology and Obstetrics, the First People's Hospital of Shangqiu and Fertility Support Center, the First Affiliated Hospital of Xinjiang Medical University from August 2014 to December 2018, 3 337 patients with POR were selected, and received controlled ovarian stimulation, embryo transplantation by IVF/ICSI and luteal support therapy. The incidence of live birth was analyzed. Univariate and multivariate Logistic analyses were used to analyze the influence of age on live birth in POR patients treated by ART. Moreover, smooth curve fitting and threshold effect analysis were conducted.ResultsOf the 3 337 cases, 1 134 obtained a live birth, the other 2 203 did not, achieving a rate of live birth of 33.98% (1 134/3 337) . Multivariate Logistic analysis result showed that, age was independently associated with live birth in POR patients treated by ART〔OR=0.920, 95%CI (0.902, 0.939) , P

Dental pulp stem cells (DPSCs) were widely used as seed cells in the field of tissue engineering and regenerative medicine, including spinal cord injury (SCI) repair and other neuronal degenerative diseases, due to their easy isolation, multiple differentiation potential, low immunogenicity and low rates of rejection during transplantation. Various studies have shown that bFGF can enhance peripheral nerve regeneration after injury, and phospho-ERK (p-ERK) activation as a major mediator may be involved in this process. Previous studies also have proved that a suitable biomaterial scaffold can carry and transport the therapeutic cells effectively to the recipient area. It has showed in our earlier experiments that 3D porous chitosan scaffolds exhibited a suitable circumstance for survival and neural differentiation of DPSCs in vitro. The purpose of the study was to evaluate the influence of chitosan scaffolds and bFGF on differentiation of DPSCs. In current study, DPSCs were cultured in chitosan scaffolds and treated with neural differentiation medium for 7 days. The neural genes and protein markers were analyzed by western blot and immunofluorescence. Meanwhile, the relevant signaling pathway involved in this process was also tested. Our study revealed that the viability of DPSCs was not influenced by co-culture with the chitosan scaffolds as well as bFGF. Compared with the control and DPSC/chitosan-scaffold groups, the levels of GFAP, S100β and β-tubulin III significantly increased in the DPSC/chitosan-scaffold+bFGF group. Chitosan scaffolds were non-cytotoxic to the survival of DPSCs, and chitosan scaffolds combined with bFGF facilitated the neural differentiation of DPSCs. The transplantation of DPSCs/chitosan-scaffold+bFGF might be a secure and effective method of treating SCI and other neuronal diseases. [ABSTRACT FROM AUTHOR]