Mi Hyeon Jang

Alcohol and nicotine reduce cell proliferation and enhance apoptosis in dentate gyrus.

It is generally accepted that alcohol and nicotine affect learning ability and memory functions, especially in adolescents. In the present study, the effects of alcohol and nicotine on cell proliferation and apoptosis in the dentate gyrus of young rats were investigated. The results show that cell proliferation is suppressed by alcohol and nicotine. Furthermore, alcohol and nicotine increase the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells. Based on the results presented in this study, it can be suggested that alcohol- and nicotine-related impairment in learning and memory functions may be due to alcohol- and nicotine-induced suppression of new cell formation and acceleration of apoptosis, especially during adolescence.

Melatonin attenuates amyloid beta25–35-induced apoptosis in mouse microglial BV2 cells

Melatonin has been reported to possess strong antioxidant actions, and is able to directly scavenge a variety of reactive oxygen species (ROS). The present study investigated whether melatonin possesses protective effects against Abeta-induced cytotoxicity in microglial cells. Cells treated with Abeta exhibited several characteristic features of apoptosis, while cells pre-treated with melatonin prior to exposure to Abeta showed a decrease in the occurrence of such apoptotic features. Several previous studies have demonstrated the involvement of ROS in Abeta-induced neurotoxicity, and ROS generated by Abeta have been reported to lead to the activation of nuclear factor-kappa B (NF-kappaB), a transcription factor; pre-treatment with melatonin in the present study reduced the level of Abeta-induced intracellular ROS generation, inhibited NF-kappaB activation, and suppressed the Abeta-induced increase in caspase-3 enzyme activity. In addition, it was found that pre-treatment with melatonin inhibits Abeta-induced increase in the levels of bax mRNA and that it enhances the level of bcl-2 expression. Based on these findings, the authors speculate that melatonin may provide an effective means of treatment for Alzheimers disease through attenuation of Abeta-induced apoptosis.

Alcohol induces apoptosis in TM3 mouse Leydig cells via bax-dependent caspase-3 activation.

To investigate whether ethanol induces apoptosis in Leydig cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA fragmentation assay, caspase-3 enzyme assay, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed on TM3 mouse Leydig cells. Through morphological and biochemical analyses, it was demonstrated that TM3 cells treated with ethanol at concentrations of 50 and 100 mM exhibit classical apoptotic features. In addition, it was shown that ethanol induces increases in levels of bax and caspase-3 and a decrease in bcl-2 expression. Based on the results, alcohol appears to activate specific intracellular death-related pathways leading to bax-dependant caspase-3 activation and the induction of apoptosis in Leydig cells.

Acupuncture suppresses ischemia-induced increase in c-Fos expression and apoptosis in the hippocampal CA1 region in gerbils.

Acupuncture has been used for the enhancement of functional recovery from various disorders including stroke. In the present study, the effects of acupuncture on the c-Fos expression and apoptosis in the hippocampal CA1 region of gerbils following transient global ischemia were investigated via immunohistochemistry for c-Fos and caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Enhanced Fos, TUNEL, and caspase-3 positivities were detected in the hippocampal CA1 region in the ischemic gerbils. Acupunctural treatment suppressed the ischemia-induced increment in the number of Fos-, TUNEL-, and caspase-3-positive cells: the most potent suppressive effect was observed at the Zusanli acupoint. These results suggest that acupunctural treatment alleviates ischemia-induced apoptosis and may aid in the recovery following ischemic cerebral injury.

Dependence of rat hippocampal c-Fos expression on intensity and duration of exercise

The expression of c-Fos, an immediately early gene, is a marker of neural activity. In the present study, the effect of treadmill exercise on c-Fos expression was investigated in various regions of the rat hippocampus via immunohistochemistry. The first part of the experiment was aimed at determining the dependence of c-Fos expression on the intensity of treadmill exercise. In most of the hippocampal regions studied, increasing c-Fos expression was observed with increasing exercise intensity. In the second part of the experiment, the dependence of c-Fos expression on the duration of treadmill exercise was investigated. The c-Fos expression induced by mild-intensity exercise increased until the 7th day of exercise and subsequently decreased. Results of the present study suggest that the effect of treadmill exercise on neuronal activity in the hippocampus is intensity-and duration-dependent.

Treadmill exercise decreases intrastriatal hemorrhage-induced neuronal cell death via suppression on caspase-3 expression in rats

Intracerebral hemorrhage is one of the most devastating types of stroke. This disease is known to cause severe neurological damage and also has a very high mortality rate. In this study, the effect of treadmill exercise on intrastriatal hemorrhage-induced neuronal cell death was investigated. Intrastriatal hemorrhage was caused by injection of collagenase into the striatum using a stereotaxic instrument. Animals of the exercise group were made to run on a treadmill for 30 min once a day during 10 consecutive days. In the present results, treadmill exercise was shown to suppress the increase in the size of hemorrhage-induced lesions and the increase in caspase-3 expression in the striatum. Based on these results, it is possible that treadmill exercise aids in the recovery from central nervous system sequelae following intracerebral hemorrhage.

Amiodarone induces apoptosis in L-132 human lung epithelial cell line

To investigate whether amiodarone induces apoptosis in cells of the L-132 human lung epithelial cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, 4,6-diamidino-2-phenylindole staining, DNA fragmentation assay, reverse transcription-polymerase chain reaction, and casapse-3 enzyme assay were performed. Through morphological and biochemical analyses, it was demonstrated that L-132 cells treated with amiodarone exhibit several features of apoptosis. In addition, it was shown that amiodarone increases the mRNA levels of bax and caspase-3. Based on the results, amiodarone appears to activate specific intracellular death-related pathways, including possibly the bax-dependent caspase-3 activation pathway, and thus induce apoptosis in human lung epithelial cells.

PROTECTIVE EFFECT OF HYPERICUM PERFORATUM LINN (ST. JOHN'S WORT) AGAINST HYDROGEN PEROXIDE-INDUCED APOPTOSIS ON HUMAN NEUROBLASTOMA CELLS

The medicinal plant Hypericum perforatum Linn, commonly known as St. Johns wort, has been used as an antidepressant. To investigate whether St. Johns wort possesses a protective effect against hydrogen peroxide (H(2)O(2))-induced cytotoxicity in neuronal cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4,6-diamidino-2-phenylindole staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, flow cytometry analysis, DNA fragmentation assay, and caspase-3 enzyme assay were performed on SK-N-MC human neuroblastoma cells. Cells treated with H(2)O(2) exhibited several apoptotic features, while those pre-treated with St. Johns wort prior to H(2)O(2) exposure showed a decreased occurrence of apoptotic features. In addition, pre-treatment with St. Johns wort inhibited H(2)O(2)-induced increase in caspase-3 enzyme activity. These results suggest that St. Johns wort may exert a protective effect against H(2)O(2)-induced apoptosis in human neuroblastoma cells.

Nicotine administration decreases nitric oxide synthase expression in the hypothalamus of food-deprived rats

Effect of nicotine on nitric oxide synthase (NOS) expression in various hypothalamic regions was investigated in rats via nicotineamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Sprague-Dawley rats were divided into the fed group, the fed and nicotine-treated group, the food-deprived group, and the food-deprived and nicotine-treated group. The fed groups received abundant food and water, while food was withheld from the food-deprived groups for 48 h. The nicotine-treated groups were injected with nicotine. Following food deprivation, enhanced NAPDH-d expression was detected in the paraventricular nucleus, ventromedial hypothalamic nucleus, and lateral hypothalamic area of the hypothalamus. Nicotine administration to the food-deprived rats resulted in decreased NADPH-d positivity. The present results indicate that nicotine administration is effective in limiting the enhancement in NOS expression following food restriction.

Acupuncture decreases ischemia-induced apoptosis and cell proliferation in dentate gyrus of gerbils

Abstract Background: Acupuncture has been used for the enhancement of functional recovery from various disorders. In the present study, the effect of acupuncture on the apoptosis and new cell proliferation in the hippocampal dentate gyrus of gerbils (n = 25) following transient global ischemia was investigated. Methods: To determine the level of apoptosis and cell proliferation, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and immunohistochemistry for 5-bromo-2′-deoxyuridine (BrdU) were employed respectively. Results: In the dentate gyrus of ischemic gerbils, the number of both TUNEL- and BrdU-positive cells (66.01 ± 2.45/mm2 and 514.38 ± 44.90/mm2) was significantly increased compared to that of the sham-operated gerbils (11.25 ± 1.85/mm2 and 111.47 ± 10.95/mm2). Among the acupuncture (ST36, LI4 or non-acupoint) treated groups, ST36 acupoint treated group showed the most potent apoptosis (20.52 ± 2.40/mm2) and proliferation (159.38 ± 24.05/mm2) suppressive effects (∼70% decreases in both apoptosis and cell proliferation). Conclusion: These results may suggest that acupuncture treatment alleviates ischemia-induced apoptosis and presents possible therapeutic potentials in the recovery from ischemic cerebral injury.