ABSTRACT
Andrographolide (ANDRO) has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains) were subjected to 3 and 21% of O2 for various times (0-12 h) to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.
Subject(s)
Animals , Mice , Astrocytes/drug effects , Autophagy/drug effects , Cell Hypoxia/drug effects , Diterpenes/pharmacology , S100 Calcium Binding Protein beta Subunit/drug effects , Apoptosis/drug effects , Astrocytes/physiology , Blotting, Western , Cell Survival/drug effects , Real-Time Polymerase Chain Reaction , S100 Calcium Binding Protein beta Subunit/metabolism , Time Factors , TransfectionABSTRACT
OBJECTIVE@#To study the expression of S100B and glial tibrillory acidic protein (GFAP) atter primary brainstem injury in rat and discuss the changes with brainstern injury time and their mechanism in the injury.@*METHODS@#The brainstem injury animal model was established using the mechanical impacting method. The HE staining, Gless argentaffin staining and SP immunohistochemical method were applied to observe the changes of S100B and GFAP at different injury time. The immunostaining results were measured statistically with imaging analysis technology.@*RESULTS@#A large number of S100B positive cells could be seen in 30 min. Afterward, expression increased gradually with time and peaked up in 24 h, and reversed back the normal in 72h. The GFAP positive cells showed rise continually in 30 min, and reached the peak in 48 h, then started to decrease, but still higher than that in control.@*CONCLUSION@#The expression of S100B and GFAP is correlated with post traumatic intervals after brainstem injury in rat, and may be useful in estimation post traumatic intervals and nerve regeneration.