Pharmaceutical effect of manganese porphyrins on manganese superoxide dismutase deficient mice.

Mice lacking manganese-superoxide dismutase (Mn-SOD) activity exhibit typical pathology of dilated cardiomyopathy (DCM). In the present study, the structure-activity relationship between the water-soluble manganese (Mn) porphyrin with SOD activity and the in vivo pharmaceutical effect on DCM is reported. The Mn-SOD-deficient mice were treated with Mn-porphyrins for 3 weeks. The treatment of a Mn-porphyrin, MnM2Py(2)P, suppressed the progression of cardiac dilation. These results suggest that the Mn-porphyrin MnM2Py(2)P treatment is proposed as a potential therapy for DCM.

Age-related changes of calcineurin and Akt1/protein kinase Balpha (Akt1/PKBalpha) immunoreactivity in the mouse hippocampal CA1 sector: an immunohistochemical study.

We investigated the age-related alterations of calcineurin and Akt1/protein kinase Balpha (Akt1/PKBalpha) immunoreactivity in the mouse hippocampal CA1 sector using immunohistochemistry. Calcineurin and Akt1/PKBalpha immunoreactivity was measured in 2-, 8-, 18-, 40-42- and 50-59-weeks-old animals. Diffuse calcineurin immunoreactivity was evident in pyramidal neurons of the hippocampal CA1 sector of 8-weeks-old mice. Densities of calcineurin immunoreactivity were lowered significantly in the hippocampal CA1 neurons of 2-weeks-old mice. In contrast, densities of calcineurin immunoreactivity were unchanged in the hippocampal CA1 neurons up to 40-42-weeks-old mice. However, densities of calcineurin immunoreactivity were increased significantly in the dendrites and plasma membranes of the hippocampal CA1 neurons of 50-59-weeks-old mice compared to 8-weeks old animals. Akt1/PKBalpha immunoreactivity was slightly detectable in the hippocampal CA1 sector of 8-weeks-old mice. A weak Akt1/PKBalpha immunoreactivity was found in cytoplasm of the hippocampal CA1 neurons and glial cells. Densities of Akt1/PKBalpha immunoreactivity were unchanged in the hippocampal CA1 neurons and glial cells of 2-weeks-old mice. In contrast, densities of Akt1/PKBalpha immunoreactivity were increased significantly in cytoplasm of neurons and glial cells of the hippocampal CA1 sector from 40-42 to 50-59 weeks after birth. The present study indicates that densities of calcineurin immunoreactivity and number of Akt1/PKBalpha immunoreactive cells were increased significantly in the hippocampal CA1 sector during aging processes. Our study also demonstrates that the activation of Akt1/PKBalpha signaling pathway may act defense mechanism against the neuronal dysfunction of the hippocampal CA1 sector caused by the activation of calcineurin signaling pathway during aging processes. These findings suggest that the calcineurin and Akt1/PKBalpha signaling pathway may be important targets for the development of novel therapeutic strategies for protection against age-related neurodegeneration.

Age-related alterations of oxidative stress markers in the mouse hippocampal CA1 sector.

We investigated the age-related alterations of Cu/Zn-SOD, Mn-SOD, cytochrome c, and HNE (4-hydroxy-2-nonenal) in the hippocampal CA1 sector of 2-, 18-, 40-, 42- and 50-59-week-old mice as compared with 8-week-old mice under the same conditions. Two-week-old mice exhibited small number of Cu/Zn-SOD-positive cells in the hippocampal CA1 sector. Thereafter, Cu/Zn-SOD-positive cells were increased gradually in the hippocampal CA1 sector from 18 to 50-59 weeks of birth. Mn-SOD-positive cells in 2-week-old mice showed a weak staining in the hippocampal CA1 sector. However, Mn-SOD-positive cells were unchanged in the hippocampal CA1 sector from 8 to 50-59 weeks of birth. Cytochrome c-positive cells in 2-week-old mice showed a weak staining in the hippocampal CA1 sector. In contrast, cytochrome c-positive cells were unchanged in the hippocampal CA1 sector up to 40-42 weeks of birth. Thereafter, cytochrome c-positive cells were decreased in the hippocampal CA1 sector of 50-59-week-old mice. HNE immunoreactivity in 2-week-old mice showed a weak density in the hippocampal CA1 sector. In contrast, the density of HNE immunoreactivity was unchanged in the hippocampal CA1 sector up to 40-42 weeks of birth. Thereafter, densities of HNE immunoreactivity were increased significantly in the hippocampal CA1 sector of 50-59-week-old mice. The present results show that the alteration of cytoplasmic Cu/Zn-SOD and lipid peroxidation was more pronounced than that of mitochondrial Mn-SOD in the vulnerable hippocampal CA1 sector during aging processes. Furthermore, the present study demonstrates that the decrease in the number of cytochrome c-positive cells and the increase of densities of HNE immunoreactivity may reflect the mitochondrial dysfunction in the hippocampal CA1 sector of aged animals. These findings suggest that the damage of mitochondrial membrane may occur in the hippocampal CA1 sector during aging processes.

Age-related changes of NGF, BDNF, parvalbumin and neuronal nitric oxide synthase immunoreactivity in the mouse hippocampal CA1 sector.

We investigated the age-related alterations in nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), parvalbumin and neuronal nitric oxide synthase (nNOS) immunoreactivity of the mouse hippocampal CA1 sector. NGF and BDNF immunoreactivity was unchanged in the hippocampal CA1 pyramidal neurons from 2 to 50-59 weeks of birth. In contrast, a significant increase in the NGF and BDNF immunoreactivity was observed in glial cells of the hippocampal CA1 sector from 40-42 to 50-59 weeks of birth. On the other hand, the number of parvalbumin- and nNOS-positive interneurons was unchanged in the hippocampal CA1 sector during aging processes, except for a significant decrease of nNOS-positive interneurons 2 weeks of birth. Our results indicate that NGF and BDNF immunoreactivity was unaltered in the hippocampal CA1 pyramidal neurons during aging processes. In contrast, a significant increase in the NGF and BDNF immunoreactivity was observed in glial cells of the hippocampal CA1 sector during aging processes. The present study also shows that the number of parvalbumin- and nNOS-positive interneurons was unchanged in the hippocampal CA1 sector during aging processes, except for a significant decrease of nNOS-positive interneurons 2 weeks of birth. These results demonstrate that the expression of glial NGF and BDNF may play a key role for helping survival and maintenance of pyramidal neurons and neuronal functions in the hippocampal CA1 sector during aging processes. Furthermore, our findings suggest that parvalbumin- and nNOS-positive interneurons in the hippocampal CA1 sector are resistant to aging processes. Moreover, our findings suggest that nitric oxide synthesized by the nNOS may play some role for neuronal growth during postnatal development.

Age-related changes of astorocytes, oligodendrocytes and microglia in the mouse hippocampal CA1 sector.

We investigated the age-related alterations of astorocyte, oligodendrocyte and microglia in the mouse hippocampal CA1 sector under the same conditions using immunohistochemistry. Glial fibrillary acidic protein (GFAP), 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and isolectin B(4) immunoreactivity was measured in 2-, 8-, 18-, 40-42- and 50-59-week-old mice. Total number of GFAP-positive cells was unchanged in the hippocampal CA1 sector up to 40-42 weeks of birth. In 50-59-week-old mice, however, a significant increase in the number of GFAP-positive cells was observed in the hippocampal CA1 sector, exhibiting the morphology of reactive astrocytes. In contrast, the fibers of CNPase immunoreactivity were unchanged in the hippocampal CA1 sector up to 18 weeks of birth. In 40-42- and 50-59-week-old mice, however, a significant decrease in the densities of CNPase-positive fibers was observed in the hippocampal CA1 sector. On the other hand, total number of isolectin B(4)-positive cells was unchanged in the hippocampal CA1 sector up to 40-42 weeks of birth. In 50-59-week-old mice, however, a significant decrease in the number of isolectin B(4)-positive cells was observed in the hippocampal CA1 sector. Our results show that astrocytes proliferate and are activated in the hippocampal CA1 sector with advancing age. Furthermore, the present study demonstrates that the fibers of oligodendrocytes and total number of microglial cells in the hippocampal CA1 sector are decreased during ageing processes. These results suggest that age-related changes of astorocytes, oligodendrocytes and microglia had occurred in the mouse hippocampal CA1 sector.

Immunohistochemical study on distribution of NF-kappaB and p53 in gerbil hippocampus after transient cerebral ischemia: effect of pitavastatin.

We investigated the immunohistochemical alterations of the transcription nuclear factor kappa-B (NF-kappaB) and transcription factor p53 in the hippocampus after transient cerebral ischemia in gerbils. We also examined the effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin against the alterations of NF-kappaB, p53 and neuronal nuclei in the hippocampus after ischemia. Severe neuronal damage was observed in the hippocampal CA1 neurons 5 and 14 days after ischemia. In the present study, the increase of NF-kappaB immunoreactivity in glial cells and p53 immunoreactivity in neurons preceded neuronal damage in the hippocampal CA1 sector after ischemia. Thereafter, NF-kappaB immunoreactivity was induced highly in reactive astrocytes and microglia of the hippocampal CA1 sector where severe neuronal damage was observed. Our immunohistochemical study showed that pitavastatin prevented the alterations of NF-kappaB and p53 in the hippocampal CA1 sector 5 days after transient ischemia. Furthermore, our results with neuronal nuclei immunostaining indicate that pitavastatin dose-dependently prevented the neuronal cell death in the hippocampal CA1 sector 5 days after transient cerebral ischemia. These results suggest that the up-regulations of NF-kappaB in glia and p53 in neurons can cause neuronal cell death after ischemia. Our findings also support the hypothesis that NF-kappaB- and/or p53-mediated neuronal cell death is prevented through decreasing oxidative stress by pitavastatin. Thus, NF-kappaB and p53 may provide an attractive target for the development of novel therapeutic approaches for brain stroke.

Postischemic alterations of BDNF, NGF, HSP 70 and ubiquitin immunoreactivity in the gerbil hippocampus: pharmacological approach.

1. We investigated the immunohistochemical alterations of BDNF, NGF, HSP 70 and ubiquitin in the hippocampus 1 h to 14 days after transient cerebral ischemia in gerbils. We also examined the effect of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor pitavastatin against the changes of BDNF, NGF, HSP 70 and ubiquitin in the hippocampus after cerebral ischemia in the hippocampus after ischemia. 2. The transient cerebral ischemia was carried out by clamping the carotid arteries with aneurismal clips for 5 min. 3. In the present study, the alteration of HSP 70 and ubiquitin immunoreactivity in the hippocampal CA1 sector was more pronounced than that of BDNF and NGF immunoreactivity after transient cerebral ischemia. In double-labeled immunostainings, BDNF, NGF and ubiquitin immunostaining was observed both in GFAP-positive astrocytes and MRF-1-positive microglia in the hippocampal CA1 sector after ischemia. Furthermore, prophylactic treatment with pitavastatin prevented the damage of neurons with neurotrophic factor and stress proteins in the hippocampal CA1 sector after ischemia. 4. These findings suggest that the expression of stress protein including HSP 70 and ubiquitin may play a key role in the protection against the hippocampal CA1 neuronal damage after transient cerebral ischemia in comparison with the expression of neurotrophic factor such as BDNF and NGF. The present findings also suggest that the glial BDNF, NGF and ubiquitin may play some role for helping surviving neurons after ischemia. Furthermore, our present study indicates that prophylactic treatment with pitavastatin can prevent the damage of neurons with neurotrophic factor and stress proteins in the hippocampal CA1 sector after transient cerebral ischemia. Thus our study provides further valuable information for the pathogenesis after transient cerebral ischemia.

Alterations of interneurons of the gerbil hippocampus after transient cerebral ischemia: effect of pitavastatin.

We investigated the immunohistochemical alterations of parvalbumin (PV)-expressing interneurons in the hippocampus after transient cerebral ischemia in gerbils in comparison with neuronal nitric oxide synthase (nNOS)-expressing interneurons. We also examined the effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin against the damage of neurons and interneurons in the hippocampus after cerebral ischemia. Severe neuronal damage was observed in the hippocampal CA1 pyramidal neurons 5 and 14 days after ischemia. The PV immunoreactivity was unchanged up to 2 days after ischemia. At 5 and 14 days after ischemia, in contrast, a conspicuous reduction of PV immunoreactivity was observed in interneurons of the hippocampal CA1 sector. Furthermore, a significant decrease of PV immunoreactivity was found in interneurons of the hippocampal CA3 sector. No damage of nNOS-immunopositive interneurons was detected in the gerbil hippocampus up to 1 day after ischemia. Thereafter, a decrease of nNOS immunoreactive interneurons was found in the hippocampal CA1 sector up to 14 days after ischemia. Pitavastatin significantly prevented the neuronal cell loss in the hippocampal CA1 sector 5 days after ischemia. Our immunohistochemical study also showed that pitavastatin prevented significant decrease of PV- and nNOS-positive interneurons in the hippocampus after ischemia. Double-labeled immunostainings showed that PV immunoreactivity was not found in nNOS-immunopositive interneurons of the brain. The present study demonstrates that cerebral ischemia can cause a loss of both PV- and nNOS-immunoreactive interneurons in the hippocampal CA1 sector. Our findings also show that the damage to nNOS-immunopositive interneurons may precede the neuronal cell loss in the hippocampal CA1 sector after ischemia and nNOS-positive interneurons may play some role in the pathogenesis of cerebral ischemic diseases. Furthermore, our present study indicates that pitavastatin can prevent the damage of interneurons in the hippocampus after cerebral ischemia. Thus, our study provides valuable information for the pathogenesis after cerebral ischemia.