Endogenous FGF21 attenuates blood-brain barrier disruption in penumbra after delayed recanalization in MCAO rats through FGFR1/PI3K/Akt pathway / 中南大学学报(医学版)

OBJECTIVES@#Restoration of blood circulation within "time window" is the principal treating goal for treating acute ischemic stroke. Previous studies revealed that delayed recanalization might cause serious ischemia/reperfusion injury. However, plenty of evidences showed delayed recanalization improved neurological outcomes in acute ischemic stroke. This study aims to explore the role of delayed recanalization on blood-brain barrier (BBB) in the penumbra (surrounding ischemic core) and neurological outcomes after middle cerebral artery occlusion (MCAO).@*METHODS@#Recanalization was performed on the 3rd day after MCAO. BBB disruption was tested by Western blotting, Evans blue dye, and immunofluorescence staining. Infarct volume and neurological outcomes were evaluated on the 7th day after MCAO. The expression of fibroblast growth factor 21 (FGF21), fibroblast growth factor receptor 1 (FGFR1), phosphatidylinositol-3-kinase (PI3K), and serine/threonine kinase (Akt) in the penumbra were observed by immunofluorescence staining and/or Western blotting.@*RESULTS@#The extraversion of Evans blue, IgG, and albumin increased surrounding ischemic core after MCAO, but significantly decreased after recanalization. The expression of Claudin-5, Occludin, and zona occludens 1 (ZO-1) decreased surrounding ischemic core after MCAO, but significantly increased after recanalization. Infarct volume reduced and neurological outcomes improved following recanalization (on the 7th day after MCAO). The expressions of Claudin-5, Occludin, and ZO-1 decreased surrounding ischemic core following MCAO, which were up-regulated corresponding to the increases of FGF21, p-FGFR1, PI3K, and p-Akt after recanalization. Intra-cerebroventricular injection of FGFR1 inhibitor SU5402 down-regulated the expression of PI3K, p-Akt, Occludin, Claudin-5, and ZO-1 in the penumbra, which weakened the beneficial effects of recanalization on neurological outcomes after MCAO.@*CONCLUSIONS@#Delayed recanalization on the 3rd day after MCAO increases endogenous FGF21 in the penumbra and activates FGFR1/PI3K/Akt pathway, which attenuates BBB disruption in the penumbra and improves neurobehavior in MCAO rats.

FGFR1 is an independent prognostic factor and can be regulated by miR-497 in gastric cancer progression

Fibroblast growth factor receptor 1 (FGFR1) has been reported in gastric cancer to be a prognostic factor. However, miR-497-targeted FGFR1 has not been explored in the carcinogenesis of gastric cancer. The present study intended to revalidate the prognostic significance of FGFR1 in patients with gastric cancer, and the mechanism of miR-497-regulated FGFR1 was investigated in gastric cancer cell proliferation and apoptosis. The messenger RNA (mRNA) and protein levels were assayed by RT-qPCR and western blotting, respectively. The targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual luciferase reporter assay. Cell proliferation was analyzed by CCK-8 assay. Annexin V-FITC/PI staining was used to evaluate the apoptosis in AGS and SGC-7901 cells. FGFR1 was frequently up-regulated in gastric cancer tissues and associated with poor overall survival in patients with gastric cancer. Interestingly, FGFR1 loss-of-function resulted in a significant growth inhibition and apoptosis in AGS and SGC-7901 cells. In addition, we found that miR-497 was inhibited in gastric cancer tissues and cell lines, while overexpression of miR-497 could suppress proliferation and induce apoptosis in AGS and SGC-7901 cells. Importantly, bioinformatics analysis and experimental data suggested that FGFR1 was a direct target of miR-497, which could inhibit FGFR1 expression when transfected with miR-497 mimics. Furthermore, we found that overexpression of FGFR1 reversed the growth inhibition and apoptosis of miR-497 mimics in AGS and SGC-7901 cells. These findings suggested that overexpression of miR-497 inhibited proliferation and induced apoptosis in gastric cancer through the suppression of FGFR1.

Fibroblast Growth Factor Receptor 1 Overexpression Is Associated with Poor Survival in Patients with Resected Muscle Invasive Urothelial Carcinoma

PURPOSE: To examine the usefulness of various receptor tyrosine kinase expressions as prognostic markers and therapeutic targets in muscle invasive urothelial cancer (UC) patients. MATERIALS AND METHODS: We retrospectively analyzed the data of 98 patients with muscle invasive UC who underwent radical cystectomy between 2005 and 2010 in Yonsei Cancer Center. Using formalin fixed paraffin embedded tissues of primary tumors, immunohistochemical staining was done for human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor 1 (FGFR1), and fibroblast growth factor receptor 3 (FGFR3). RESULTS: There were 41 (41.8%), 44 (44.9%), and 14 (14.2%) patients who have over-expressed HER2, FGFR1, and FGFR3, respectively. In univariate analysis, significantly shorter median time to recurrence (TTR) (12.9 months vs. 49.0 months; p=0.008) and overall survival (OS) (22.3 months vs. 52.7 months; p=0.006) was found in patients with FGFR1 overexpression. By contrast, there was no difference in TTR or OS according to the HER2 and FGFR3 expression status. FGFR1 remained as a significant prognostic factor for OS with hazard ratio of 2.23 (95% confidence interval: 1.27-3.90, p=0.006) in multivariate analysis. CONCLUSION: Our result showed that FGFR1 expression, but not FGFR3, is an adverse prognostic factor in muscle invasive UC patients after radical cystectomy. FGFR1 might be feasible for prognosis prediction and a potential therapeutic target after thorough validation in muscle invasive UC.

The expression of bFGF and its receptor FGFR1 in rat after fluid-percussive brain injury / 法医学杂志

OBJECTIVE@#Study on the pattern of changes of bFGF and FGFR1 immunoreactivity occurred in the experimental brain injury model for the purpose of providing the scientific basis for molecular pathological diagnosis, forensic identification, clinical treatment as well as further ascertaining the molecular mechanism of brain injury.@*METHODS@#Male SD rats were divided into normal control, sham operation control and injury groups. The rats of injury groups were subjected to moderate lateral fluid percussion brain injury (0.2 mPa). The injury groups were then subdivided into 30 min, 1, 3, 6, 12 h, 1, 3, 7 d groups according to the time elapsed after injury. The SP immunohistochemistry method was used to examine the expression of both bFGF and FGFR1 factors in rat brain.@*RESULTS@#In the brain of normal control and sham operation control groups, the low expression levels of bFGF and FGFR1 were observed. The increase of bFGF and FGFR1 immunoreactivity could be observed 6 h after injury in cortex and brain stem, reached to the peak at 1 d and remained at the high level up to 3 d, then partly declined at 7 d. In hippocampus, however, the increase occur as early as 3 h after injury, reached to the peak at 1 d and then decreased progressively, and returned to basal level at 7 d.@*CONCLUSION@#The results suggested that brain injury induced the gene expressions of bFGF and FGFR1. The bFGF may contribute to maintenance of nerve cell survival and the repair of damaged neural tissues after CNS injury and the patterns of their level change were quite regular and can be used for timing of injury in forensic medicine aspect.