Research progress on the regulation of craniofacial development and malformation by fibroblast growth factor 8 / 口腔疾病防治

@#Fibroblast growth factor 8 (FGF8) is a kind of secretory polypeptide that has crucial roles in the development of various tissues and organs. Current studies have found that FGF8 can regulate the differentiation of cranial neural crest cells by activating the mitogen-activated protein kinase (MAPK) signaling pathway and affect the establishment of mandibular arch polarity and the development of craniofacial symmetry by regulating the expression of target genes. Cleft lip with or without cleft palate, ciliopathies, macrostomia and agnathia are four developmental malformations involving the craniofacial region that seriously affect the quality of life of patients. The abnormal FGF8 signal caused by gene mutation, abnormal protein conformation or expression is closely related to the occurrence of craniofacial malformations, but the molecular mechanism and signaling pathway underlying these malformations have not been fully elucidated. Craniofacial development is a complex process mediated by a variety of signaling molecules. In the future, the role of various signaling molecules in craniofacial development and malformations need to be explored to provide a new perspective and vision for the prevention and treatment of these craniofacial malformations.

Role of fibroblast growth factor 8 in process of dental epithelium-induced directional differentiation of human postnatal dental pulp stem cells into odontoblasts and pulp cells / 中国病理生理杂志

AIM: To study the effects of fibroblast growth factor 8 (FGF8) on directional differentiation of human dental pulp stem cells (hDPSCs) into odontoblasts and pulp tissue.METHODS: hDPSCs were isolated and cultured, and identified with flow cytometry by detecting cell surface markers of hDPSCs.FGF8 at concentration of 50 μg/L was added into the mineralization fluid to induce the differentiation of the hDPSCs.The mRNA expression of dentin sialophosphoprotein (DSPP), alkaline phosphatase (ALP), bone sialoprotein (BSP) and core-binding factor alpha 1 (Cbfa-1) in differentiated cells was detected by real-time PCR.FGF8 and mouse E11.5 dental epithelium formed restructuring cell group with hDPSCs, and then the restructuring cell group was transplanted under renal capsule membrane in nude mice for tissue culture.DNA in situ hybridization was used to identify the sources of odontoblasts and pulp cells.RESULTS: The surface markers of CD29 and CD90 showed positive in isolated hDPSCs.FGF8 induced hDPSCs to form a distinct mineralization nodule, and the expression of dentin-specific proteins, DSPP, BSP and Cbfa-1, was increased.hDPSCs were induced to differentiate into odontoblasts and pulp cells by E11.5 dental epithelium and FGF8.CONCLUSION: FGF8 can assist dental epithelium to induce directional differetiation of hDPSCs into odontoblasts and pulp cells, and formation of dentin and dental pulp cavity structure.

Hypospadias induced by maternal exposure to di-n-butyl phthalate and its mechanisms in male rat offspring / 中华男科学杂志

Objective@#To induce hypospadias in male rat offspring by maternal exposure to di-n-butyl phthalate (DBP) during late pregnancy and further investigate its mechanisms.@*METHODS@#We randomly divided 20 pregnant rats into a DBP exposure and a control group, the former treated intragastrically with DBP while the latter with soybean oil at 750 mg per kilogram of the body weight per day from gestation days (GD) 14 to 18. On postnatal day (PND) 1, we recorded the incidence rate of hypospadias and observed the histopathological changes in the genital tubercle of the hypospadiac rats. We also measured the level of serum testosterone (T) by radioimmunoassay and determined the mRNA and protein expressions of the androgen receptor (AR), sonic hedgehog (Shh), bone morphogenetic protein 4 (Bmp4) and fibroblast growth factor 8 (Fgf8) in the genital tubercle by real-time PCR and Western blot.@*RESULTS@#No hypospadiac male rats were found in the control group. The incidence rate of hypospadias in male offspring was 43.6% in the DBP-treatment group. Histological analysis confirmed hypospadiac malformation. The serum testosterone concentration was decreased in the hypospadiac male rats as compared with the controls (［0.49 ± 0.05］ vs ［1.12 ± 0.05］ ng/ml, P <0.05). The mRNA expressions of AR, Shh, Bmp4 and Fgf8 in the genital tubercle were significantly lower in the hypospadiac male rats than in the controls (AR: 0.50 ± 0.05 vs 1.00 ± 0.12, P <0.05; Shh: 0.65 ± 0.07 vs 1.00 ± 0.15, P <0.05; Bmp4: 0.42 ± 0.05 vs 1.00 ± 0.13, P <0.05; Fgf8: 0.46 ± 0.04 vs 1.00 ± 0.12, P <0.05), and so were their protein expressions (AR: 0.34 ± 0.05 vs 1.00 ± 0.09, P <0.05; Shh: 0.51 ± 0.07 vs 1.00 ± 0.12, P <0.05; Bmp4: 0.43 ± 0.05 vs 1.00 ± 0.11, P <0.05; Fgf8: 0.57 ± 0.04 vs 1.00 ± 0.13, P <0.05).@*CONCLUSIONS@#Maternal exposure to DBP during late pregnancy can induce hypospadias in the male rat offspring. DBP affects the development of the genital tubercle by reducing the serum T concentration and expressions of AR, Shh, Bmp4 and Fgf8 in the genital tubercle, which might underlie the mechanism of DBP inducing hypospadias.

The cloning and expression of the fibroblast growth factor eight / 中国免疫学杂志

Objective:To clone and express mouse fibroblast growth factor eight(FGF 8) and investigate the function of it Methods:According to the published sequence of mouse fibroblast growth factor 8, a pair of special primers was designed Then the full length cDNA of FGF 8b (a predominant isoform of FGF 8) was isolated from the total RNA of the mouse embryo by means of reverse transcription PCR and subcloned into the yeast expression vector of pYEX4T 1 in correct direction It was identified with sequencing The recombinant plasmid was transformed into yeasts The fusion protein expressed was verified by using Western blot The activity of the protein was examined by MTT and 3H TdR incorporation Results:The cDNA fragment was about 600 bps, and proved to be "b" isoform of FGF 8 exactly This fusion protein, with molecular weight about 55 kD, was highly expressed in yeast system The data of MTT and 3H TdR incorporation in NIH3T3 cells were increased obviously by the protein, and decreased by the antagonist Conclusion:Fibroblast growth factor eight was cloned and expressed.The protein was found to be capable of stimulating the proliferation of NIH3T3 cells Moreover, the recombinant protein of the extracellular fragment of FGFR1 can antagonize the response of NIH3T3 to the recombinant protein