scholarly journals Hyperglycemia and Hypercapnia Suppress BDNF Gene Expression in Vulnerable Regions after Transient Forebrain Ischemia in the Rat

1997 ◽  
Vol 17 (12) ◽  
pp. 1303-1308 ◽  
Author(s):  
H. Uchino ◽  
O. Lindvall ◽  
B. K. Siesjö ◽  
Z. Kokaia

Preischemic hyperglycemia or superimposed hypercapnia exaggerates brain damage caused by transient forebrain ischemia. Because high regional levels of brain-derived neurotrophic factor (BDNF) protein correlate with resistance to ischemic damage, we studied the expression of BDNF mRNA using in situ hybridization in rats subjected to 10 minutes of forebrain ischemia under normoglycemic, hyperglycemic, or hypercapnic conditions. Compared with normoglycemic animals, the increase of BDNF mRNA in dentate granule cells was attenuated and that in CA3 pyramidal neurons completely prevented in hyperglycemic rats. No ischemia-induced increases of BDNF mRNA levels in the hippocampal formation were detected in hypercapnic animals. Hyperglycemic and hypercapnic rats showed transiently decreased expression of BDNF mRNA levels in the cingulate cortex, which was not observed in normoglycemic animals. The results suggest that suppression of the BDNF gene might contribute to the increased vulnerability of the CA3 region and cingulate cortex in hyperglycemic and hypercapnic animals.

1995 ◽  
Vol 15 (6) ◽  
pp. 1132-1136 ◽  
Author(s):  
Masafumi Tagaya ◽  
Tomohiro Matsuyama ◽  
Hitoshi Nakamura ◽  
Ryuji Hata ◽  
Souichiro Shimizu ◽  
...  

To assess whether ischemia could induce GAP-43 mRNA expression, we performed in situ hybridization in gerbil brains that had been subjected to 5 min of global ischemia. In control dentate granule cells, little hybridization was detected in contrast to the intense signal generated by pyramidal neurons of the adult hippocampal formation. After ischemia, we detected a robust GAP-43 signal over hippocampal granule cells at 3 h of reperfusion, persisting through 7 days, and disappearing by 14 days. This demonstrated GAP-43 gene induction after ischemia, and suggests that GAP-43 may be involved in reactive events, including fiber sprouting and synaptic reorganization, that follow ischemia.


2021 ◽  
Vol 22 (2) ◽  
pp. 644
Author(s):  
Hyejin Sim ◽  
Tae-Kyeong Lee ◽  
Yeon Ho Yoo ◽  
Ji Hyeon Ahn ◽  
Dae Won Kim ◽  
...  

Calbindin-D28k (CB), a calcium-binding protein, mediates diverse neuronal functions. In this study, adult gerbils were fed a normal diet (ND) or exposed to intermittent fasting (IF) for three months, and were randomly assigned to sham or ischemia operated groups. Ischemic injury was induced by transient forebrain ischemia for 5 min. Short-term memory was examined via passive avoidance test. CB expression was investigated in the Cornu Ammonis 1 (CA1) region of the hippocampus via western blot analysis and immunohistochemistry. Finally, histological analysis was used to assess neuroprotection and gliosis (microgliosis and astrogliosis) in the CA1 region. Short-term memory did not vary significantly between ischemic gerbils with IF and those exposed to ND. CB expression was increased significantly in the CA1 pyramidal neurons of ischemic gerbils with IF compared with that of gerbils fed ND. However, the CB expression was significantly decreased in ischemic gerbils with IF, similarly to that of ischemic gerbils exposed to ND. The CA1 pyramidal neurons were not protected from ischemic injury in both groups, and gliosis (astrogliosis and microgliosis) was gradually increased with time after ischemia. In addition, immunoglobulin G was leaked into the CA1 parenchyma from blood vessels and gradually increased with time after ischemic insult in both groups. Taken together, our study suggests that IF for three months increases CB expression in hippocampal CA1 pyramidal neurons; however, the CA1 pyramidal neurons are not protected from transient forebrain ischemia. This failure in neuroprotection may be attributed to disruption of the blood–brain barrier, which triggers gliosis after ischemic insults.


1994 ◽  
Vol 26 (1-2) ◽  
pp. 135-142 ◽  
Author(s):  
Kazuki Yabuuchi ◽  
Masabumi Minami ◽  
Seishi Katsumata ◽  
Akira Yamazaki ◽  
Masamichi Satoh

Development ◽  
1994 ◽  
Vol 120 (6) ◽  
pp. 1643-1649 ◽  
Author(s):  
K.H. Herzog ◽  
K. Bailey ◽  
Y.A. Barde

Using a sensitive and quantitative method, the mRNA levels of brain-derived neurotrophic factor (BDNF) were determined during the development of the chick visual system. Low copy numbers were detected, and BDNF was found to be expressed in the optic tectum already 2 days before the arrival of the first retinal ganglion cell axons, suggesting an early role of BDNF in tectal development. After the beginning of tectal innervation, BDNF mRNA levels markedly increased, and optic stalk transection at day 4 (which prevents subsequent tectal innervation) was found to reduce the contralateral tectal levels of BDNF mRNA. Comparable reductions were obtained after injection of tetrodotoxin into one eye, indicating that, already during the earliest stages of target encounter in the CNS, the degree of BDNF gene expression is influenced by activity-dependent mechanisms. BDNF mRNA was also detected in the retina itself and at levels comparable to those found in the tectum. Together with previous findings indicating that BDNF prevents the death of cultured chick retinal ganglion cells, these results support the idea that the tightly controlled expression of the BDNF gene might be important in the co-ordinated development of the visual system.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2477
Author(s):  
Bora Kim ◽  
Tae-Kyeong Lee ◽  
Cheol Woo Park ◽  
Dae Won Kim ◽  
Ji Hyeon Ahn ◽  
...  

Pycnogenol® (an extract of the bark of French maritime pine tree) is used for dietary supplement and known to have excellent antioxidative efficacy. However, there are few reports on neuroprotective effect of Pycnogenol® supplementation and its mechanisms against ischemic injury following transient forebrain ischemia (TFI) in gerbils. Now, we examined neuroprotective effect and its mechanisms of Pycnogenol® in the gerbils with 5-min TFI, which evokes a significant death (loss) of pyramidal cells located in the cornu ammonis (CA1) region of gerbil hippocampus from 4–5 days post-TFI. Gerbils were pretreated with 30, 40, and 50 mg/kg of Pycnogenol® once a day for 7 days before TFI surgery. Treatment with 50 mg/kg, not 30 or 40 mg/kg, of Pycnogenol® potently protected learning and memory, as well as CA1 pyramidal cells, from ischemic injury. Treatment with 50 mg/kg Pycnogenol® significantly enhanced immunoreactivity of antioxidant enzymes (superoxide dismutases and catalase) in the pyramidal cells before and after TFI induction. Furthermore, the treatment significantly reduced the generation of superoxide anion, ribonucleic acid oxidation and lipid peroxidation in the pyramidal cells. Moreover, interestingly, its neuroprotective effect was abolished by administration of sodium azide (a potent inhibitor of SODs and catalase activities). Taken together, current results clearly indicate that Pycnogenol® supplementation can prevent neurons from ischemic stroke through its potent antioxidative role.


2000 ◽  
Vol 20 (7) ◽  
pp. 1089-1095 ◽  
Author(s):  
Bing R. Hu ◽  
Chun L. Liu ◽  
Darren J. Park

Extracellular regulated kinase (ERK) transduce growth factor signals while c-Jun NH(2)-terminal kinase (JNK) delivers stress signals into the nuclei for regulation of gene expression. These signaling pathways were studied by laser-scanning confocal microcopy and Western blot analysis using phospho-specific antibodies on rat brains that were subjected to 15 minutes transient forebrain ischemia followed by varied periods of reperfusion. Extracellular regulated kinase was activated at 30 minutes and 4 hours of reperfusion in the nuclei and dendrites of surviving dentate gyrus (DG) cells, but not in dying CA1 neurons after ischemia. Tyrosine phosphorylation of Trk kinase, an ERK upstream growth factor receptor, was elevated in the DG tissue, and to a lesser extent in the CA1 region. In addition, phosphorylation of activating transcription factor-2 (ATF-2) and c-Jun was selectively increased in CA1 dying neurons during the late period of reperfusion. These findings suggested that the Trk-ERK signaling pathway might be neuroprotective for dentate granule cells. The activation of ATF-2 and c-Jun pathways in the late period of reperfusion in CA1 dying neurons might reflect damage signals in these neurons. These results suggested that the lack of protective signals acting in concert with the presence of damage signals in CA1 neurons after ischemia might contribute to delayed neuronal death after transient forebrain ischemia.


Sign in / Sign up

Export Citation Format

Share Document