Analysis of glial cell line-derived neurotrophic factor-inducible zinc finger protein 1 expression in human diseased kidney

The glial cell line-derived neurotrophic factor (GDNF)-RET signaling pathway plays an important role in kidney development. We have previously identified a novel zinc finger protein, glial cell line-derived neurotrophic factor-inducible zinc finger protein 1 (GZF1), whose expression was induced in the human neuroblastoma cell line TGW expressing RET by GDNF stimulation and was also detected in mouse metanephric kidney. In the present study, we examined the immunohistochemical expression of GZF1 in normal human kidney and various kidney diseases including chronic kidney disease, acute kidney injury, and cancers, and assessed the clinical significance of GZF1 expression. In the normal kidney, GZF1 was highly expressed only in the proximal tubular epithelial cells that were also positive for angiotensin-converting enzyme. We also evaluated GZF1 expression in various kidney diseases including membranous nephropathy, minimal change nephrotic syndrome with or without acute kidney injury, immunoglobulin A nephropathy, diabetic nephropathy, acute tubular necrosis, and antineutrophil cytoplasmic antibody-related glomerulonephritis. We found that decreased expression of GZF1 was associated with an increase in tubulointerstitial damage and serum creatinine levels. In addition, GZF1 expression was undetectable or very low in most cases of renal cell carcinomas and Wilms tumors. These findings suggest that GZF1 represents a new marker for renal proximal tubules and that there is an inverse correlation between the expression level of GZF1 and tubular function.     

1,25-Dihydroxyvitamin D3 administration to 6-hydroxydopamine-lesioned rats increases glial cell line-derived neurotrophic factor and partially restores tyrosine hydroxylase expression in substantia nigra and striatum

It has previously been demonstrated that 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] administration, whether in cell cultures or in vivo to rats, increases glial cell line-derived neurotrophic factor (GDNF) expression levels, suggesting that this hormone may have beneficial effects in neurodegenerative disorders. This study was carried out to explore the effects of 1,25(OH)(2)D(3) administration in a 6-OHDA-lesioned rat model of Parkinson's disease on GDNF and tyrosine hydroxylase (TH) expression in substantia nigra (SN) and striatum. Two groups of animals received 1,25(OH)(2)D(3) intraperitoneally, the first group 7 days before the unilateral injection of 6-OHDA into the medial forebrain bundle (MFB) and the second group 21 days (days 21-28) after the unilateral injection of 6-OHDA. Animals of both groups were sacrificed on day 28. In addition, two other groups received a unilateral injection of either saline or 6-OHDA into the MFB. Rats were killed, and the SN and striatum were then removed for GDNF and TH determination. Striatal GDNF protein expression was increased on the ipsilateral with respect to the contralateral side after 6-OHDA injection alone as well as in 1,25(OH)(2)D(3)-treated rats before or after 6-OHDA administration. As expected, 6-OHDA injection induced an ipsilateral decrease in TH-immunopositive neuronal cell bodies and axonal terminals in the SN and striatum. However, treatment with 1,25(OH)(2)D(3) before and after 6-OHDA injection partially restored TH expression in SN. These data suggest that 1,25(OH)(2)D(3) may help to prevent dopaminergic neuron damage.     

局灶性脑缺血再灌注时胶质细胞源性神经营养因子在大鼠脑组织表达及其意义的实验研究

目的观察胶质细胞源性神经营养因子（glial cell fine-derived neuno-trophic factor,GDNF）在大鼠脑缺血再灌注时的表达特点,及其在脑缺血再灌注中的作用。方法阻断大鼠大脑中动脉（middle cerebral artery,MCA）血流2h,再灌注3—120h制成脑缺血再灌注模型。苏木精－伊红染色评价缺血性脑损伤的组织学特点,免疫组织化学（immunohistochemistry,IHC）染色观察GDNF、iNOS表达特点。结果再灌注12h组开始出现神经元不可逆变性,24h梗死形成。正常组和假手术组未检测到GDNF的表达。再灌注3—120h,在整个再灌注过程中GDNF阳性的细胞在3h达到高峰,后逐渐下降,各组与再灌注3h组比较P〈0．01。结论脑缺血后再灌注,变性、死亡的神经元不表达GDNF,缺血周边区和非缺血区神经元GDNF表达明显增强,提示GDNF有促进神经元存活作用。缺血再灌注时活化的小胶质细胞或巨噬细胞可能表达GDNF。为临床早期使用GDNF减少脑损害,提供了一定的参考价值。     

Glial cell line-derived neurotrophic factor in Purkinje cells of adult zebrafish: An autocrine mode of action?

Glial cell line-derived neurotrophic factor (GDNF) has a neuroprotective role in Purkinje cells of cerebellum, promoting the survival and the differentiation of these cells. Its signalling is mediated by a receptorial complex GFRalpha1/RET. In the brain of adult zebrafish (Danio rerio) we previously investigated GDNF expression and localization, but no data exist regarding GFRalpha1 and RET presence. Thus, the present study was designed to clarify the morphological relation between GDNF and its receptorial complex GFRalpha1/RET immunoreactivity in the cerebellum of adult zebrafish. The expression of gdnf, GFRalpha1 and ret genes was demonstrated in adult zebrafish cerebellum by a standard RT-PCR. The distribution of GDNF and its receptorial complex GFRalpha1/RET was examined by single and double immunocytochemical stainings. In the valvula and corpus cerebelli GDNF, GFRalpha1 and RET immunoreactivity was seen co-localized in Purkinje cells, identified morphologically and by using an antiserum against a specific marker for these cells, aldolase C enzyme. In the vestibulolateralis lobe, Purkinje neurons were lacking in both the eminentiae granulares and medial caudal lobe. These results demonstrated the expression of the GDNF receptorial complex in adult zebrafish cerebellum and suggest an autocrine mode of action of GDNF in Purkinje cells.     

GDNF Expression in Terminal Schwann Cells Associated With the Periodontal Ruffini Endings of the Rat Incisors During Nerve Regeneration

The terminal Schwann cells (TSCs) which play crucial roles in regeneration of the periodontal Ruffini endings (RE) exhibit immunoreaction for glial cell line‐derived neurotrophic factor (GDNF). However, no information is available regarding the role of GDNF in the periodontal RE during nerve regeneration. This study was undertaken to examine the changes in GDNF expression in the rat periodontal RE following transection of the inferior alveolar nerve (IAN) using immunohistochemistry for GDNF and S‐100 protein, a marker for the TSCs. We additionally investigated the changes in expression of GDNF in the trigeminal ganglion (TG) at protein and mRNA levels. A transection to IAN induced a disappearance of the TSCs from the alveolus‐related part (ARP), followed by a migration of spindle‐shaped cells with S‐100 but without GDNF immunoreactions into the tooth‐related part (TRP) by postoperative (PO) week 2. At PO week 2, GDNF immunoreacted cellular elements increased in number in the ARP although the spindle‐shaped cells without GDNF reaction remained in the TRP. After PO week 4, many GDNF‐positive TSCs appeared in the ARP though the spindle‐shaped cells vanished from the TRP. A real time RT‐PCR analysis demonstrated the highest elevation of GDNF mRNA in the TG at PO week 2. These findings suggested the involvement of this molecule in the maturation and maintenance of the periodontal RE during regeneration. Taken together with our previous and current studies, it appears that the regeneration of the periodontal RE is controlled by multiple neurotrophins in a stage‐specific manner. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.     

GDNF‐enhanced axonal regeneration and myelination following spinal cord injury is mediated by primary effects on neurons

We previously demonstrated that coadministration of glial cell line‐derived neurotrophic factor (GDNF) with grafts of Schwann cells (SCs) enhanced axonal regeneration and remyelination following spinal cord injury (SCI). However, the cellular target through which GDNF mediates such actions was unclear. Here, we report that GDNF enhanced both the number and caliber of regenerated axons in vivo and increased neurite outgrowth of dorsal root ganglion neurons (DRGN) in vitro, suggesting that GDNF has a direct effect on neurons. In SC‐DRGN coculture, GDNF significantly increased the number of myelin sheaths produced by SCs. GDNF treatment had no effect on the proliferation of isolated SCs but enhanced the proliferation of SCs already in contact with axons. GDNF increased the expression of the 140 kDa neural cell adhesion molecule (NCAM) in isolated SCs but not their expression of the adhesion molecule L1 or the secretion of the neurotrophins NGF, NT3, or BDNF. Overall, these results support the hypothesis that GDNF‐enhanced axonal regeneration and SC myelination is mediated mainly through a direct effect of GDNF on neurons. They also suggest that the combination of GDNF administration and SC transplantation may represent an effective strategy to promote axonal regeneration and myelin formation after injury in the spinal cord. © 2009 Wiley‐Liss, Inc.     

丙戊酸钠对帕金森病小鼠多巴胺能神经元及胶质细胞源性神经营养因子表达的影响

帕金森病(Parkinson's disease ,PD)是一种神经系统退行性疾病,主要表现为中脑黑质致密部多巴胺能神经元的丧失,纹状体多巴胺含量下降[1],至今尚无有效的治疗手段.丙戊酸钠(valproate,VPA) 是临床上作为治疗双相精神障碍的药物,能有效控制患者的躁狂和抑郁症状[2].胶质细胞源性神经营养因子(glial cell line derived neurotrophic factor,GDNF)最初从大鼠胶质瘤细胞系B49条件培养液中分离纯化,对大鼠中脑多巴胺能神经元有特异性营养作用[3].为探讨VPA对小鼠帕金森病中脑黑质多巴胺能神经元及纹状体GDNF表达的影响,本研究拟用C57BL小鼠1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyfidine,MPTP)法建立帕金森病模型,通过中脑黑质致密部(SNc)酪氨酸羟化酶(TH)的免疫组织化学染色及原位杂交方法观察纹状体GDNF表达,有望为PD寻求更有效的治疗手段,并对VPA更广泛的临床应用提供依据.     

Hepatocyte growth factor,vascular endothelial growth factor,glial cell-derived neurotrophic factor and nerve growth factor are differentially affected by early chronic ethanol or red wine intake

Ethanol intake during pregnancy and lactation induces severe changes in brain and liver throughout mechanisms involving growth factors. These are signaling molecules regulating survival, differentiation, maintenance and connectivity of brain and liver cells. Ethanol is an element of red wine which contains also compounds with antioxidant properties. Aim of the study was to investigate differences in hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), glial cell-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in brain areas and liver by ELISA of 1-month-old male mice exposed perinatally to ethanol at 11 vol.% or to red wine at same ethanol concentration. Ethanol was administered before and during pregnancy up to pups’ weaning. Ethanol per se elevated HGF in liver and cortex, potentiatied liver VEGF, reduced GDNF in the liver and decreased NGF content in hippocampus and cortex in the offspring. We did not find changes in HGF or NGF due to red wine exposure. However, we revealed elevation in VEGF levels in liver and reduced GDNF in the cortex of animals exposed to red wine but the VEGF liver increase was more marked in animals exposed to ethanol only compared to the red wine group. In conclusion the present findings in the mouse show differences in ethanol-induced toxicity when ethanol is administered alone or in red wine that may be related to compounds with antioxidant properties present in the red wine.