• Clinical and Experimental Pediatrics
• /
• v.51 no.10
• /
• pp.1112-1117
• /
• 2008

Purpose : We intended to observe cell death and apoptotic changes in neurons in organotypic hippocampal slice cultures following oxygen-glucose deprivation (OGD), using propidium iodide (PI) uptake, Fluoro-Jade (FJ) staining, TUNEL staining and immunofluorescent staining for caspase-3. Methods : The hippocampus of 7-day-old rats was cut into $350{\mu}m$ slices. The slices were cultured for 10 d (date in vitro, DIV 10) and and exposed to OGD for 60 min at DIV 10. They were then incubated for reperfusion under normoxic conditions for an additional 48 h. Fluorescence of PI uptake was observed at predetermined intervals, and the cell death percentage was recorded. At 24 h following OGD, the slices were Cryo-cut into $15{\mu}m$ thicknesses, and Fluoro-Jade staining, TUNEL staining, and immunofluorescence staining for caspase-3 were performed. Results : 1) PI uptake was restricted to the pyramidal cell layer and DG in the slices after OGD. The fluorescent intensities of PI increased from 6 to 48 h during the reperfusion stage. The cell death percentage significantly increased time-dependently in CA1 and DG following OGD (P<0.05). 2) At 24 h after OGD, many FJ positive cells were detected in CA1 and DG. Some neurons had distinct nuclei and processes while others had fragmented nuclei and disrupted processes in CA1. TUNEL and immunofluorescent staining for caspase-3 showed increased expression of TUNEL labeling and caspase-3 in CA1 and DG at 24 h after OGD. Conclusion : The numerous dead cells in the slice cultures after OGD tended to display apoptotic changes mediated by the activation of caspase-3.

• Molecules and Cells
• /
• v.43 no.3
• /
• pp.276-285
• /
• 2020

Circadian rhythm is an endogenous oscillation of about 24-h period in many physiological processes and behaviors. This daily oscillation is maintained by the molecular clock machinery with transcriptional-translational feedback loops mediated by clock genes including Period2 (Per2) and Bmal1. Recently, it was revealed that gut microbiome exerts a significant impact on the circadian physiology and behavior of its host; however, the mechanism through which it regulates the molecular clock has remained elusive. 3-(4-hydroxyphenyl)propionic acid (4-OH-PPA) and 3-phenylpropionic acid (PPA) are major metabolites exclusively produced by Clostridium sporogenes and may function as unique chemical messengers communicating with its host. In the present study, we examined if two C. sporogenes-derived metabolites can modulate the oscillation of mammalian molecular clock. Interestingly, 4-OH-PPA and PPA increased the amplitude of both PER2 and Bmal1 oscillation in a dose-dependent manner following their administration immediately after the nadir or the peak of their rhythm. The phase of PER2 oscillation responded differently depending on the mode of administration of the metabolites. In addition, using an organotypic slice culture ex vivo, treatment with 4-OH-PPA increased the amplitude and lengthened the period of PER2 oscillation in the suprachiasmatic nucleus and other tissues. In summary, two C. sporogenes-derived metabolites are involved in the regulation of circadian oscillation of Per2 and Bmal1 clock genes in the host's peripheral and central clock machineries.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.2
• /
• pp.416-425
• /
• 2005

This study demonstrated neuroprotective and anti-oxidative effects of Puerariae Radix for cerebral ischemia. Neuroprotective effects were studied by using oxygen/glucous deprivation of the organotypic hippocampal slice cultures to complement limitations of in vivo and in vitro models for cerebral ischemia study. Anti-oxidative effects were studied on BV-2 microglia cells damaged by $H_2O_2$ and nitric oxide. The results obtained are as follows; The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in CA1 region of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in DG region of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of TUNEL-positive cells in both CA1 region and DG region of ischemic damaged hippocampus cultures. The group treated with $50\;{\mu}g/m{\ell}$ of Puerariae Radix demonstrated significant decrease of TUNEL-positive cells in CA1 region. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of LDH concentrations in culture media of ischemic damaged hippocampus cultures. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant increases of cell viabilities of BV-2 microglia cells damaged by $H_2O_2$. The group treated with $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant increase of cell viability of BV-2 microglia cells damaged by nitric oxide. These results suggested that Puerariae Radix of cerebral ischemic revealed neuroprotective effects through the control effect of apoptosis and oxidative damages.

• Clinical and Experimental Pediatrics
• /
• v.45 no.12
• /
• pp.1551-1558
• /
• 2002

Purpose : Loss of hippocampal interneurons in dentate gyrus has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainic acid(KA). Interneurons contain $Ca^{2+}$- binding protein parvalbumin(PV). The effects of kainic acid on parvalbumin-immunoreactive (PV-IR) interneurons in dentate gyrus were investigated in organotypic hippocampal slice cultures. Methods : Cultured hippocampal slices from postnatal day nine C57/BL6 mice were exposed to $10{\mu}M$ KA, and were observed at 0, 8, 24, 48, 72 hours after a one hour KA exposure. Neuronal injury was determined by morphologic changes of PV-IR interneuron in dentate gyrus. Results : Transient(1 hour) exposure of hippocampal explant cultures to KA produced marked varicosities in dendrites of PV-IR interneuron in dentate gyrus and the shaft of interbeaded dendrite is often much thinner than those in control. The presence of varicosities in dendrites was reversible with KA washout. The dendrites of KA treated explants were no longer beaded at 8, 24, 48 and 72 hours after KA exposure. The number of cells in PV-IR interneurons in dentate gyrus was decreased at 0, 8 hours after exposure. But there was no significant difference in 24, 48 and 72 hours recovery group compared with control group. Conclusion : The results suggested that loss of PV-IR interneurons in dentate gyrus is transient, and is not accompanied by PV-IR interneuronal cell death.