Objective It has traditionally been difficult to isolate and culture mouse bone marrow mesenchymal stem cells (BMSC),which has low success rate.And thus restricts the development of related research to some extent.We aimed to optimize the whole bone marrow adherent method for isolation and culture of mouse bone marrow mesenchymal stem cells and search for an effective method of inducing BMSCs to differentiate into alveolar epithelial cells.Methods Bone marrow contents harvested from the tibia and femur of C57BL/6 mice were cultured based on the whole bone marrow adherent method.The timing and split ratios of passage were determined according to the size and number of cell colonies.After 6 passages,cells were counted to detect cell proliferation ability,surface markers were examined by flow cytometry and Small Airway Epithelial Cell Medium (SAEpiCM) was used to induce the differentiation of BMSCs.Results With the increase of passages and the purity of BMSCs,the proliferation of cells at passages 6 tended to be stable.Flow cytometry showed that they were strongly positive for bone marrow mesenchymal stem cell surface markers CD29 and Sca-1 (99.1％,88.5％),but almost negative for the surface marker of hematopoietic stem cells CD117 (0.008 2％).BMSCs cultured in SA-EpiCM showed an epithelium-like morphological change and expressed surfactant associated protein C,a specific marker of alveolar epithelial cells.Conclusion It is effective to isolate and culture mouse bone marrow mesenchymal stem cells by adjusting the timing and split ratios of passage according to the size and number of the clonal cell colonies,which possessed the potential to differentiate into alveolar epithelial cells.

[Objective]To investigate the effects of ghrelin on inflammatory signaling protein kinase B(Akt),nuclear factor-κB(NF-κB)and inducible nitric oxide synthase(iNOS)in alveolar macrophage(AM).[Methods]24 Male SD rats were randomly divided into Sham,CLP,CLP+ghrelin,and Sham+ghrelin groups. Cecal ligation and puncture(CLP)was used to induce sepsis. Ghrelin(20 nmol/kg)was administered by intraperitoneal injection at 3 h and 15 h post-operation. Histopathological changes of lungs were observed and scored.AM were extracted from bronchoalveolar lavage fluid(BALF). Interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in BALF were detected by ELISA. IL-1β,TNF-α,and IL-6 mRNA in AM were detected by qPCR.NF-κB p65,IκBα,p-IκBα,Akt,p-Akt and iNOS in AM were detected by immunofluorescence(IF)and Western blotting.[Results]The histologic score(6.7±0.8),BALF IL-1β[(146±12)pg/mL]and IL-6[(182±10)pg/mL]from CLP+ghrelin group were respectively 35.4%,44.5% and 46.42% lower than those from CLP group[(10.3±0.7),(263±17)pg/mL,and(273±5)pg/mL],P<0.05.No significant difference was found in BALF TNF-α between CLP group and CLP+ghrelin group.The IL-1β,TNF-α and IL-6 mRNA in AM from CLP+ghrelin group were respectively 54.38%,53.6% and 46.42% lower than those from CLP group,P<0.05. The nuclear NF-κB p65 and cytoplasmic p-IκBα,p-Akt and iNOS from CLP+ghrelin group were respectively 32.58%,45.42%,27.6% and 48.33% lower than those from CLP group,P<0.05. There was no significant difference in all data between Sham group and Sham+ghrelin group.[Conclusion]Ghrelin can decrease the activity of inflammatory signaling proteins Akt,NF-κB and iNOS in AM,therefore restricts AM expressing pro-inflammatory cytokines IL-1β,TNF-α,and IL-6,thus alleviates sep-sis-induced acute lung injury(ALI).

Odontogenesis is a consequence of a complex series of reciprocal signal interactions between odontogenic epithelium and neural crest-derived odontotgenic mesenchyme. These interactions result from a complex interplay of genetic and environmental factors. Given that a fetus develops in the mother, maternal health and environmental exposures have a great influence on tooth development. In this review, we focused on the key issues in the developmental defects of teeth induced by various types of maternal environmental factors, including environmental endocrine disruptors, joint action of two or more chemical exposures, and maternal health status. This review also discussed the adverse effects of maternal environmental factors on tooth development. These effects include enamel developmental defects, molar incisor hypomineralization, dental fluorosis, hyperdontia and hypodontia. Overall, this review provides a theoretical basis for the prevention of tooth defects in early life, assessment of risks from developmental tooth defects, and advancement of pediatric oral health management.

Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day (E) 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factor-β signalling pathway might play a role in this process.

Enamel formation is a series of complex physiological processes, which are regulated by critical genes spatially and temporally. These processes involve multiple developmental stages covering ages and are prone to suffer signal interference or gene mutations, ultimately leading to developmental defects of enamel (DDE). Epigenetic modifications have important regulatory roles in gene expression during enarnel development. New technologies including high-throughput sequencing, chromatin immunoprecipitation sequencing (ChIP-seq), and DNA methylation chip are emerging in recent years, making it possible to establish genome-wide epigenetic modification profiles during developmental processes. The regulatory role of epigenetic modification with spatio-temporal pattern, such as DNA methylation, histone modification and non-coding RNA, has significantly expanded our understanding of the regulatory network of enamel formation, providing a new theoretical basis of clinical management and intervention strategy for DDE. The present review briefly describes the enamel formation process of human beings' teeth as well as rodent incisors and summarizes the dynamic characteristics of epigenetic modification during enamel formation. The functions of epigenetic modification in enamel formation and DDE are also emphatically discussed.
Humans ; Epigenesis, Genetic ; Developmental Defects of Enamel ; DNA Methylation ; Oligonucleotide Array Sequence Analysis ; Dental Enamel

Background/Aims: Low educational attainment is a well-established risk factor for nonalcoholic fatty liver disease (NAFLD) in developed areas. However, the association between educational attainment and the risk of NAFLD is less clear in China. Methods: A cross-sectional study including over 200,000 Chinese adults across mainland China was conducted. Information on education level and lifestyle factors were obtained through standard questionnaires, while NAFLD and advanced fibrosis were diagnosed using validated formulas. Outcomes included the risk of NAFLD in the general population and high probability of fibrosis among patients with NAFLD. Logistic regression analysis was employed to estimate the risk of NAFLD and fibrosis across education levels. A causal mediation model was used to explore the potential mediators. Results: Comparing with those receiving primary school education, the multi-adjusted odds ratios (95% confidence intervals) for NAFLD were 1.28 (1.16 to 1.41) for men and 0.94 (0.89 to 0.99) for women with college education after accounting for body mass index. When considering waist circumference, the odds ratios (95% CIs) were 0.94 (0.86 to 1.04) for men and 0.88 (0.80 to 0.97) for women, respectively. The proportions mediated by general and central obesity were 51.00% and 68.04% for men, while for women the proportions were 48.58% and 32.58%, respectively. Furthermore, NAFLD patients with lower educational attainment showed an incremental increased risk of advanced fibrosis in both genders. Conclusions In China, a low education level was associated with a higher risk of prevalent NAFLD in women, as well as high probability of fibrosis in both genders.