rhEPO对缺糖缺氧大鼠星形胶质细胞GLT-1和GLAST表达的影响

为了研究重组人促红细胞生成素(rhEPO)对缺糖缺氧(OGD)培养大鼠星形胶质细胞GLT-1和GLAST表达的影响,将缺糖缺氧培养星形胶质细胞分成不同浓度rhEPO处理组:0、20、100U/mL,不同浓度rhEPO与星形胶质细胞在缺氧缺糖条件下培养6h,用RT-PCR测定GLT-1和GLAST的mRNA表达变化,免疫印迹技术测定GLT-1和GLAST蛋白的表达变化。20、100U/mL rhEPO星形胶质细胞GLT-1的mRNA和蛋白质水平较OGD对照组明显升高(P0.05),GLAST的mRNA和蛋白质水平变化不明显(P0.05)。GLT-1水平可能与rhEPO对缺糖缺氧培养大鼠星形胶质细胞的保护作用有关。     

Astrocytic responses in the lateral geniculate nucleus of monkeys with experimental glaucoma

Objective To investigate the responses of lateral geniculate nucleus (LGN) astrocytes to experimental glaucoma in monkeys. Animal studied Rhesus monkeys (Macaca mulatta). Procedures Unilateral chronic elevation of intraocular pressure (IOP) was induced in six rhesus monkeys by laser photocoagulation of the trabecular meshwork. Four normal monkeys were used as controls. Immunohistochemistry with antibodies to glial fibrillary acidic protein (GFAP), S100β and parvalbumin was used to specifically label astrocytes and neurons in the LGN. The relative immunointensity (RI) of GFAP was defined as the ratio of intensity between each region of interest to a reference field and compared between the experimental and control groups as a function of percentage optic nerve fiber loss. Ultrastructural changes of LGN astrocytes were examined by transmission electron microscopy. Results An increase in GFAP and S100β immunoreactivity was observed in the LGN layers receiving projections from the experimental glaucoma eyes. Quantitative analysis revealed that the RI of GFAP in both the magnocellular and parvocellular layers connected to the glaucomatous eyes increased in a linear fashion with increasing optic nerve fiber loss. Compared to controls, the RI of GFAP was also moderately elevated in LGN layers connected to the fellow nonglaucomatous eyes. Ultrastructurally, accumulation of glial filaments that occurred throughout the perikaryon and extended into the process in reactive astrocytes was observed in LGN layers of glaucomatous monkeys. Conclusions Reactive astrogliosis occurs in the magnocellular and parvocellular LGN layers of monkeys with unilateral glaucoma. Astrocytes may play an important role in the regulation of LGN microenvironment in glaucoma.     

Dietary curcumin supplementation attenuates 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in C57BL mice

Studies in vivo and in vitro suggest that curcumin is a neuroprotective agent. Experiments were conducted to determine whether dietary supplementation with curcumin has neuroprotective effects in a mouse model of Parkinson’s disease (PD). Treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) significantly induced the loss of dopaminergic cells in the substantia nigra and deletion of dopamine in the striatum, which was attenuated by long-term (7 weeks) dietary supplementation with curcumin at a concentration of 0.5% or 2.0% (w/w). Although curcumin did not prevent the MPTP-induced apoptosis of neuroblasts in the subventricular zone (SVZ), it promoted the regeneration of neuroblasts in the anterior part of the SVZ (SVZa) at 3 days after MPTP treatment. Furthermore, curcumin enhanced the MPTP-induced activation of microglia and astrocytes in the striatum and increased the expression of glial cell line-derived neurotrophic factor (GDNF) and transforming growth factor-β1 (TGFβ1) in the striatum and SVZ. GDNF and TGFβ1 are thought to play an important role in protecting neurons from injury in the central and peripheral nervous systems. These results suggest that long-term administration of curcumin blocks the neurotoxicity of MPTP in the nigrostriatal dopaminergic system of the mouse and that the neuroprotective effect might be correlated with the increased expression of GDNF and TGFβ1. Curcumin may be effective in preventing or slowing the progression of PD.     

长春碱纳米粒的细胞毒性和急性毒性研究

【目的】探讨长春碱聚氰基丙烯酸正丁酯纳米粒(VLB-PBCA-NP)对正常细胞的毒性及其急性毒性。【方法】采用MTT法并结合形态学观察,比较了VLB-PBCA-NP和VLB原料药对原代大鼠星形胶质细胞和小鼠成纤维细胞L929的毒性;用相同剂量的VLB-PBCA-NP和VLB原料药溶液对小鼠进行尾静脉注射,每日观察小鼠死亡情况,并计算半数致死量(LD50)。【结果】在质量浓度为0.5~50 ng/mL时,VLB-PBCA-NP和VLB原料药对星形胶质细胞增殖抑制率的影响无显著性差异,当质量浓度达到500和5000 ng/mL时,VLB-PBCA-NP对大鼠星形胶质细胞的毒性显著低于VLB原料药(P<0.05)。5000 ng/mL的VLB-PBCA-NP对小鼠成纤维细胞L929的毒性为3级,极显著降低了VLB原料药的毒性(P<0.01)。VLB-PBCA-NP和VLB原料药的LD50分别为26.38和22.7mg/kg,前者较后者提高了16.21%。【结论】VLB-PBCA-NP对小鼠的急性毒性和对非肿瘤细胞的毒性均显著低于VLB原料药。     

Gamma-ray irradiation stimulates the expression of caveolin-1 and GFAP in rat spinal cord: a study of immunoblot and immunohistochemistry

We studied the expression of caveolin-1 in the spinal cords of rats using ⁶⁰Co γ-ray irradiation (single dose of 8 Gray (Gy)) in order to determine the possible involvement of caveolin-1 in the tissues of the central nervous system after irradiation. Spinal cords sampled at days 1, 4, and 9 post-irradiation (PI) (n = 5 per each time point) were analyzed by Western blot and immunohistochemistry. Western blot analysis showed that the expression of caveolin-1 was significantly increased at day 1 PI (p < 0.05), and returned to the level of normal control rats on days 4 and 9 PI. Immunohistochemistry showed that caveolin-1 immunoreactivity was enhanced in some glial cells, vascular endothelial cells, and neurons in the spinal cords. The increased expression of glial fibrillary acidic protein (GFAP), a marker for an astroglial reaction, was consistent with that of caveolin-1. In addition, caveolin-1 was co-localized in hypertrophied GFAP-positive astrocytes. Taking all these facts into consideration, we postulate that irradiation induces the increased expression of caveolin-1 in cells of the central nervous system, and that its increased expression in astrocytes may contribute to hypertrophy of astrocytes in the spinal cord after irradiation. The precise role of caveolin-1 in the spinal cords should be studied further.     

Diverse functions of perlecan in central nervous system cells in vitro

Therapeutic treatment targeting one cell type is considered ineffective in remedying any injury to the central nervous system (CNS). Perlecan, a multi‐functional, heparan sulfate proteoglycan, shows diverse effects on distinct cell types, suggesting that it is one of the candidates that can augment the regenerative mechanisms in the injured CNS. Therefore, we examined the functions of perlecan in CNS cells in vitro by using perlecan purified from bovine kidney. Perlecan‐coated cell culture plates, unlike their type I/III collagen‐coated counterparts, did not inhibit the adhesion of neural stem/progenitor cells (NS/PCs) and neurons. The coated perlecan and the perlecan added to the culture medium suppressed astrocyte proliferation; however, perlecan added to the medium promoted NS/PC proliferation. Neurons were promoted to extend their neurites on the perlecan‐coated substrate, and perlecan added to the medium also showed a similar effect. NS/PC proliferation and neurite extension is a major regenerative reaction in CNS injury, whereas excess proliferation of astrocytes cause hypertrophy of glial scars, which repels neurons. Our in vitro study suggests that perlecan is an attractive candidate to promote regenerative mechanisms and to suppress reactions that hamper regenerative processes in cases of CNS injury.     

星形细胞瘤及星形细胞反应性增生中胶质原纤维酸性蛋白和DNA的定量研究

用全自动图像分析仪，对４０例－Ⅰ－Ⅳ级星形细胞瘤及１０例星形细胞反应增生了胶质原纤维酸性蛋白免疫组化及ＤＮＡ组织化学的定量研究，结果显示：星形细胞反应性增生时，ＧＦＡＰ含量高于星形细胞瘤，随着星形细胞瘤分级的递增，ＧＦＡＰ含量农渐降低，ＤＮＡ含量恰好遵循相反的规律；ＧＦＡＰ和ＤＮＡ含量之间有良好的线性相关关系。     

大豆黄酮对多氯联苯引起的鸡胚下丘脑星形胶质细胞损伤的缓解作用

实验建立了鸡胚下丘脑星形胶质细胞体外培养模型,研究了大豆黄酮对多氯联苯Aroclor 1254(A1254)引起的下丘脑星形胶质细胞损伤的缓解作用。结果表明:0.1～1μg/mL的A1254引起的细胞损伤不显著,高剂量时(10μg/mL)能引起星形胶质细胞大量死亡。抗氧化剂大豆黄酮10μg/mL能明显缓解A1254对星形胶质细胞的损伤作用。     

Microglia and astrocyte activation in the spinal cord of lame horses

Objective

To determine the microglial and astrocyte response to painful lameness in horses.

Long-term survival of a dog with Alexander disease

A 1-year- and 11-month-old spayed female toy poodle had showed progressive ataxia and paresis in the hindlimbs since 11 months old. Magnetic resonance imaging revealed high signal intensity on T2-weighted and fluid-attenuated inversion recovery images at the thoracic and lumbar spinal cord. The dog’s neurological condition slowly deteriorated and flaccid tetraparesis was exhibited. At 4 years and 11 months old, the dog died of respiratory failure. On postmortem examination, eosinophilic corkscrew bundles (Rosenthal fibers) were observed mainly in the thoracic and lumbar spinal cord. Histological features were comparable to previously reported cases with Alexander disease. This is a first case report to describe the clinical course and long-term prognosis of a dog with Alexander disease.