Maternal zinc deficiency impairs brain nestin expression in prenatal and postnatal mice

Effects of maternal dietary zinc deficiency on prenatal and postnatal brain development were investigated in ICR strain mice. From d 1 of pregnancy (E0) until postnatal d 20 (P20), maternal mice were fed experimental diets that contained 1 mg Zn/kg/day (severe zinc deficient, SZD), 5 mg Zn/kg/day (marginal zinc deficient, MZD), 30 mg Zn/kg/day (zinc adequately supplied, ZA) or 100 mg Zn/kg/day (zinc supplemented, ZS and pair-fed, PF). Brains of offspring from these dietary groups were examined at various developmental stages for expression of nestin, an intermediate filament protein found in neural stem cells and young neurons. Immunocytochemistry showed nestin expression in neural tube 10.5 d post citrus (dpc) as well as in the cerebral cortex and neural tube from 10.5 dpc to postnatal d 10 (P10). Nestin immunoreactivities in both brain and neural tube of those zinc-supplemented control groups (ZA, ZS, PF) were stronger than those in zinc-deficient groups (SZD and MZD). Western blot analysis confirmed that nestin levels in pooled brain extracts from each of the zinc-supplemented groups (ZA, ZS, PF) were much higher than those from the zinc-deficient groups (SZD and MZD) from 10.5 dpc to P10. Immunostaining and Western blots showed no detectable nestin in any of the experimental and control group brains after P20. These observations of an association between maternal zinc deficiency and decreased nestin protein levels in brains of offspring suggest that zinc deficiency suppresses development of neural stem cells, an effect which may lead to neuroanatomical and behavioral abnormalities in adults.

GABA transporter 1 transcriptional starting site exhibiting tissue specific difference

GABA transporter 1(GAT1) takes important roles in multiple physiological processes through the uptake and release of GABA, but the regulation of GAT1 gene expression in different tissues is rarely known. To address the question, first, 5’ Rapid amplification of cDNA end (RACE) was used to determine GAT1 transcriptional starting sites in neonatal mouse cerebral cortex and intestine, adult mouse brain and adult rat testis. The products of 5’RACE were confirmed by DNA sequencing. We found that the transcript of GAT1 in neonatal mouse cerebral cortex and adult mouse brain starts at the same site (inside of exon 1), while in mouse intestine, GAT1 starts transcription in intron 1, and in rat testis, the transcript of GAT1 has an additional untranslation exon to the 5’ direction.

Expression of estrogen receptor (ER) -α and -βtranscripts in the neonatal and adult rat cerebral cortex, cerebellum, and olfactory bulb

In the present study expression of estrogen receptor subtype -alpha (ERalpha) and -beta (ERbeta) in the cerebral cortex, cerebellum, and olfactory bulb was investigated and compared between neonatal (1 to approximately 3-days-old) and adult (250 to approximately 350 g) rats, using reverse transcription-polymerase chain reaction (RT-PCR). No ERalpha transcripts were detectable in the adult cerebellum and olfactory bulb, whereas very weak expression of ERalpha was present in the adult cerebral cortex. No significant difference in ERbeta transcripts was detectable between the neonatal and adult rats. While transcripts for both ER subtypes were co-expressed in these brain areas of neonatal rats, although ERalpha expression was significantly weaker than ERbeta. Even in the cerebral cortex known to contain both ER subtypes in adult rats, ERalpha transcripts in neonatal rats were much higher than in adult. These observations provide evidence for the existence of different expression patterns of ERalpha/ERbeta transcripts in these three brain areas between the neonatal and adult rats, suggesting that each ER subtype may play a distinct role in the regulation of differentiation, development, and functions of the brain by estrogen.

Batroxobin Against Anoxic Damage of Rat Hippocampal Neurons in Culture:Morphological Changes and Hsp70 Expression

Batroxobin,the thrombin-like enzyme,is used for therapeutic defibrination. We have found that batroxobin has good therapeutic effect in ischemic reperfusion rats and clinical practices in vivo. But we have not studied the neuroprotective effect of batroxobin on anoxic hippocampal neurons in vitro. The purpose of this study was to obtain further information on the mechanism of the batroxobin-induced neuroprotection and examine the neuroprotective effect on neurons exposed to anoxia. The effect of batroxobin on anoxic damages in cultured hippocampal neurons of neonatal rats was investigated by using morphological changes and heat shock protein 70Kd (Hsp70) immunoreactive expression as indicators. The results indicate that batroxobin, besides its defibrination, may have a direct neuroprotective effect on anoxic damage of hippocampal neurons.

RADIX SALVIAE MILTIORRHIZAE PROTECTS RAT HIPPOCAMPAL NEURON IN CULTURE FROM ANOXIC DAMAGE

Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicinal herb, has been used to improve blood circulation and resolve blood stasis. We have previously found that RSM has neuroprotective effect on ischemia and/ or ischemia-reperfusion rats. The purpose of this study was to obtain further information on the mechanism of the RSM-in-duced neuroprotection and to examine the neuroprotective effect on neurons exposed to anoxia. The effect of RSM on anoxic damage in cultured hippocampal neurons of neonatal rat was investigated by using morphological changes and heat shock protein 70kD (HSP70) expression as indicators. RSM given 0.5h before 2h-anoxia followed by 48 hours reoxygenation could significantly increase survival rate of hippocampal neurons and number of HSP70 positive cells. The results suggest that RSM has a direct neuroprotective effects on anoxic damage in hippocampal neurons.