Fibroblast Growth Factor 21 Attenuates Diabetes-Induced Renal Fibrosis by Negatively Regulating TGF-β-p53-Smad2/3-Mediated Epithelial-to-Mesenchymal Transition via Activation of AKT

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is required for renal fibrosis, which is a characteristic of diabetic nephropathy (DN). Our previous study demonstrated that fibroblast growth factor 21 (FGF21) prevented DN associated with the suppressing renal connective tissue growth factor expression, a key marker of renal fibrosis. Therefore, the effects of FGF21 on renal fibrosis in a DN mouse model and the underlying mechanisms were investigated in this study.METHODS: Type 1 diabetes mellitus was induced in C57BL/6J mice by intraperitoneal injections of multiple low doses of streptozotocin. Then, diabetic and non-diabetic mice were treated with or without FGF21 in the presence of pifithrin-α (p53 inhibitor) or 10-[4′-(N,N-Diethylamino)butyl]-2-chlorophenoxazine hydrochloride (10-DEBC) hydrochloride (Akt inhibitor) for 4 months.RESULTS: DN was diagnosed by renal dysfunction, hypertrophy, tubulointerstitial lesions, and glomerulosclerosis associated with severe fibrosis, all of which were prevented by FGF21. FGF21 also suppressed the diabetes-induced renal EMT in DN mice by negatively regulating transforming growth factor beta (TGF-β)-induced nuclear translocation of Smad2/3, which is required for the transcription of multiple fibrotic genes. The mechanistic studies showed that FGF21 attenuated nuclear translocation of Smad2/3 by inhibiting renal activity of its conjugated protein p53, which carries Smad2/3 into the nucleus. Moreover pifithrin-α inhibited the FGF21-induced preventive effects on the renal EMT and subsequent renal fibrosis in DN mice. In addition, 10-DEBC also blocked FGF21-induced inhibition of renal p53 activity by phosphorylation of mouse double minute-2 homolog (MDM2).CONCLUSION: FGF21 prevents renal fibrosis via negative regulation of the TGF-β/Smad2/3-mediated EMT process by activation of the Akt/MDM2/p53 signaling pathway.

Effect of orthodontic traction on the microstructure of dental enamel / 南方医科大学学报

OBJECTIVE@#To investigate the effect of orthodontic traction on the microstructure of dental enamel.@*METHODS@#Forty-eight isolated premolars were randomly divided into 6 groups (=8), including Group A (blank control group), in which the teeth were bonded with the orthodontic brackets without any loading force; Groups B1, B2, and B3 where the teeth were bonded with the orthodontic brackets using clinical adhesives and loaded with 50 g force for 6 months, 200 g force for 6 months, and 200 g force for 1 month, respectively; and Groups C1 and C2, where the teeth were bonded with straight wire brackets using light curing bonding and chemical curing bonding techniques, respectively. All the teeth were embedded with non-decalcified epoxy resin. Scanning electron microscope (SEM), atomic force microscope (AFM), and energy spectrometer (EDS) were used to analyze interface morphology and elemental composition of the teeth sliced with a hard tissue microtome.@*RESULTS@#Compared with those in Group A, the teeth in the other 5 groups showed increased adhesive residue index with microcracks and void structures on the enamel surface under SEM; AFM revealed microcracks on the enamel surface with angles to the grinding direction. A larger loading force on the bracket resulted in more microcracks on the enamel interface. The interface roughness differed significantly between Groups A and C2, and the peak-to-valley distance differed significantly between Groups A, C, and C2.@*CONCLUSIONS@#Orthodontic traction can cause changes in the microstructure of normal dental enamel.

Therapeutic Effects of Fibroblast Growth Factor-21 on Diabetic Nephropathy and the Possible Mechanism in Type 1 Diabetes Mellitus Mice

Background@#Fibroblast growth factor 21 (FGF21) has been only reported to prevent type 1 diabetic nephropathy (DN) in the streptozotocin-induced type 1 diabetes mellitus (T1DM) mouse model. However, the FVB (Cg)-Tg (Cryaa-Tag, Ins2-CALM1) 26OVE/PneJ (OVE26) transgenic mouse is a widely recommended mouse model to recapture the most important features of T1DM nephropathy that often occurs in diabetic patients. In addition, most previous studies focused on exploring the preventive effect of FGF21 on the development of DN. However, in clinic, development of therapeutic strategy has much more realistic value compared with preventive strategy since the onset time of DN is difficult to be accurately predicted. Therefore, in the present study OVE26 mice were used to investigate the potential therapeutic effects of FGF21 on DN. @*Methods@#Four-month-old female OVE26 mice were intraperitoneally treated with recombinant FGF21 at a dose of 100 µg/kg/day for 3 months. The diabetic and non-diabetic control mice were treated with phosphate-buffered saline at the same volume. Renal functions, pathological changes, inflammation, apoptosis, oxidative stress and fibrosis were examined in mice of all groups. @*Results@#The results showed that severe renal dysfunction, morphological changes, inflammation, apoptosis, and fibrosis were observed in OVE26 mice. However, all the renal abnormalities above in OVE26 mice were significantly attenuated by 3-month FGF21 treatment associated with improvement of renal adenosine 5´-monophosphate (AMP)-activated protein kinase (AMPK) activity and sirtuin 1 (SIRT1) expression. @*Conclusion@#Therefore, this study demonstrated that FGF21 might exert therapeutic effects on DN through AMPK-SIRT1 pathway.

Clinical analysis of children primitive neuroectodermal tumor / 医学研究生学报

Objective Primitive neuroectodermal tumor ( PNET) is a small round cell tumor occurring mostly in children or young adults and categorized into the Ewing sarcoma family of tumors, the purpose of the study was to investigate the clinical features, treatment and prognosis of Children PNET. Methods A retrospective study was performed on clinical data of 13 children with PNET hospitalized in our hospital from March 2010 to Octorber 2014.In order to analyze the clinical effects and prognostic results, statistical analysis was made on their clinical manifestations, CT and ultrasonic results, therapeutic schemes, postoperative pathology and immu-nohistochemical staining results, along with telephone and outpaitient follow-up of average 19 months. Results Of the 13 patients, 4 cases were central nervous system PNET(CNS-PNET) and 9 cases were peripheral PNET(pPNET).The clinical manifestations of the former were headache, vomiting, convolsion, movement disorder or decreased muscle strength, while the latter mainly showed mas-ses and abdominal distention.3 cases with metastasis to lung, lymph nodes and bones respectively showed masses on surface or in cavi-ty in imaging.Homer-Wright pseudorosette textures were found in 12 patients.Immunohistochemical results showed 11 cases with CD99(+), 9 cases with VIM(+) and 8 cases Syn( +).Among 11 patients underwent chemotherapy, 2 cases were lost to follow-up, 7 cases were in stable condition without occurrence and the other 2 cases recurred 4-6 months after chemotherapy.3 of 4 cases with CNS-PNET survived with the sequelae of decreased muscle strength, convolsion and movement disorder.1 case with CNS-PNET and 1 case with pPNET died 7 months and 16 months after diagnosis respectively. Conclusion PNET in children is a very highly malignant tumor with low long-term survival rate.Immunohistochemi-cal examination including CD99 and VIM is of important diagnostic value and CNS-PNET is prone to sequelae.