The Study On The Expression Of β₁ Integrin And MMP-2 In Cultured Neonatal Rat Astrocytes During Hypoxia-ischemia/reoxygenation And FDP Intervention

ObjectiveThis paper is to study the expression alterations of β₁ integrin and matrix metalloproteinase-2(MMP-2) in cultured neonatal rat astrocyte (AC) and the correlation between them during experimentalhypoxia-ischemia/reoxygenation(HI/RO) and the intervention of fructose-l,6-disphosphate(FDP) and to explore the effects and mechanism of β₁ integrin and MMP-2 in the astrocytes on the condition of HI/RO and the influence of FDP on the β₁ integrin and MMP-2 expression of astrocytes cell during HI/RO damage, which would provide the laboratory and theory recognition for hypoxia-ischemia brain damage mechanism and management.MethodsThe original cultivating mature purified AC were randomly divided into five groups:(1) the HI group: the astrocytes was exposed to \%O2, without FBS and glucose culture medium for 12h and 24h respectively.(2) FDP protect group: the astrocytes was exposed to 1%O2, without FBS and glucose and added into FDP 20 u I/ml culture medium for 12h and 24h respectively.(3) RO group: the astrocytes subjected to 12h HI, then transferred to ordinary culture for 6h, 12h and 24h respectively.(4) FDP treatment group: the astrocytes subjected to 12h HI, then transferred to ordinary culture and added FDP 20 u I/ml into culture medium 6h, 12h and 24h respectively.(5) control group: normal oxygen cultivated group.The AC body and foot process changes of each sample was observed by light microscope and scanning electron microscope and the expression alterations of β₁ integrin mRNA were determined by real-time PCR and the expression alterations of β₁ integrin and MMP-2 protein were determined by immunofluorescence.Results1. As the time of HI/RO prolonged, AC pattern in morphology changed obviously, mainly showing on the decrease of link between cells, the constracting of cell body, lessening of cell foot process. In FDP protect 12h group and FDP treatment 6h group, AC pattern changed slightly.2. As the time of HI/RO prolonged, the expression level of β₁ integrinmRNA and protein in AC significantly decreased (P<0.05). The (3j integrin mRNA and protein expression of FDP protect group obviously increased compared with the same period of HI group (P<0.05) and them of FDP treatment group obviously increased compared with the same period of RO group (P<0.05).3. As the time of HI/RO prolonged, the expression of MMP-2 protein in AC obviously increased in FDP protect group evidently increased compared with the same period of HI group (P<0.05) and their expression in FDP protect group significantly decreased compared with the same period of HI Group (P<0.05) and their expression in FDP treatment group obviously decreased compared with the same period of RO group (P<0.05).4. The relationship of Pi integrin and MMP-2 protein expression showed a negative correlation during AC HI/RO damage.Conclusion1. During AC HI/RO damage, the expression of Pi integrin in AC decreased and MMP-2 increased and the links between AC were broken, which may affect the normal pattern and function of AC.2. FDP could maintain links between AC and normal pattern of AC and reduce the AC damage from HI/RO through increasing the expression of Pi integrin and decreasing the expression of MMP-2.