摘要
系统观察大鼠ＣＮＳ针刺损伤后表达ｂＦＧＦ、ＦＧＦ受体（ＦＧＦＲ）和ＧＦＡＰ的细胞种类、时相以及相互影响，探讨ＦＧＦＲ抑制剂——５′－ＭＴＡ对体内反应性星形胶质化的影响。将７５ 只ＳＤ雄性大鼠均分１５ 组：伤后０．５ ｈ～３０ ｄ 处死的实验组与对照组。将２０ 只雄性Ｗｉｓｔａｒ大鼠均分２ 大组。甲组伤后４ ｄ 处死（５ 只加药鼠），乙组伤后８ ｄ 处死（５ 只加药鼠）；其中非加药鼠作相应单纯损伤对照组。ＨＥ染色和免疫组化染色观测ｂＦＧＦ、ＦＧＦＲ和ＧＦＡＰ表达并作形态定量分析。伤后０．５ ｈ，星形胶质细胞（Ａｓ）胞核肿胀；尔后伤道周围神经元脱失；４ ｄ 起受损组织渐为反应性Ａｓ填补；ＧＦＡＰ反应于４～７ ｄ 达顶峰。４～６ ｈ，Ａｓ 和神经元表达ｂＦＧＦ先后增强；２～４ ｄ，脑内ｂＦＧＦ水平最高，以Ａｓ为主；核仁ｂＦＧＦ亦为阳性。１２ ｈ，ＦＧＦＲ表达轻度增强，１ ｄ 时达高峰，随即回落。５′－ＭＴＡ加药组，４ ｄ 时伤区细胞数量及ｂＦＧＦ和ＧＦＡＰ表达强度均低于对照组；加药组伤道（８ ｄ）明显宽于对照组。提示：脑损伤后Ａｓ首先反应性表达ｂＦＧＦ，Ａｓ 自分泌ｂＦＧＦ是反应性星形胶质化的主要始动机制。ｂＦＧＦ可能内化入核仁发挥效应。伤?
This study is aimed to determine: 1. the cell types, after rat brain stab wound, which dynamically express bFGF, FGFR and GFAP, and interaction of these cells; 2. the interference of 5′ methylthioadenosine (5′ MTA), an inhibitor of FGFR, with the reactive astrogliosis of rat brain. This study was divided into 2 parts. Ⅰ. Seventy five SD rats (male, 200～250 g) were divided into 15 groups (average 5). One group accepted sham operation as control, and the other 14 groups were punctured and sacrificed at designed time points (0 5 h～30 d). Ⅱ. Twenty Wistar rats (male 200～250 g) were divided into 2 groups (average 10). Five rats of one group had brain injury and administered 5′ MTA for 3 days, while the other 5 rats with same insult had 5′ MTA for 7 days. The other 10 rats only had brain injury as control. HE, immunohistochemistry of bFGF, FGFR and GFAP with frozen and paraffin sections were stained and determined with morphometry. The main findings were as follows: Swelling of astocytic nuclei is the earliest changes appeared at 0 5 hour after insult and red neurons appeared at 1st hour. Neuronal loss occurred at 4th hour. From 4th day the injured tissue was gradually filled with hypertrophic astrocytes. At the same time astrogliosis was sharply marked by GFAP stain. Astrocytes firstly enhanced its expression of bFGF at 4th hour, 2 hours prior to increased expression of bFGF in neurons. bFGF reaction appeared robust around 2nd day and astrocytes were the main source of bFGF, simultaneously bFGF positive stained area also existed in extracellular matrix with undefined shape, and internalization of bFGF was also found in nucleoli of both neurons and astrocytes. Astrocytes and neurons exhibit their FGFR positive stain from 12 hours after injury, enhanced slightly around one day and quickly declined. 5′ MTA administration decreased the cell number adjacent to the injury and weakened the reaction of bFGF and GFAP compared with those of the control at 4th day; eight days later, the lesion width interfered with 5′ MTA was apparently wider than that of the control. The above results strongly suggested: (1) Reactive increase of bFGF expression is firstly observed in astrocytes at 4th hour after injury, followed by neurons' at 6th hour. bFGF autocrine is the main initiation mechanism of astrogliosis. (2) bFGF could be internalized into nucleoli of both astrocytes and neurons in the area where cells were actively expressing bFGF. (3) Reactive expression of FGFR is a transient event with mild degree, thus may inhibit neurotrophic effect of the bFGF system. (5) 5′ MTA could partly block the reactive astrogliosis.
基金
国家自然科学基金!资助项目(39470287)
关键词
颅脑损伤
BFGF
FGFR
5'-MTA
大鼠
brain injury
basic fibroblast growth factor
astrogliosis
5' methylthioadenosine
rat
