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Superoxide dismutases, SOD1 and SOD2, play a distinct role in the fat body during pupation in silkworm Bombyx mori.

Nojima Y, Ito K, Ono H, Nakazato T, Bono H, Yokoyama T, Sato R, Suetsugu Y, Nakamura Y, Yamamoto K, Satoh J, Tabunoki H, Fugo H - PLoS ONE (2015)

Bottom Line: One way that aerobic biological systems counteract the generation of reactive oxygen species (ROS) is with superoxide dismutase proteins SOD1 and SOD2 that metabolize superoxide radicals to molecular oxygen and hydrogen peroxide or scavenge oxygen radicals produced by the extensive oxidation-reduction and electron-transport reactions that occur in mitochondria.We found that BmSOD2 had a unique expression pattern in the fat body through the fifth instar larval developmental stage.These results suggest that BmSOD1 and BmSOD2 modulate environmental oxidative stress in the cell and have a specific role in fat body of B. mori during pupation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan; Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Noshio, 2-522-1, Kiyose, Tokyo 204-8588, Japan.

ABSTRACT
One way that aerobic biological systems counteract the generation of reactive oxygen species (ROS) is with superoxide dismutase proteins SOD1 and SOD2 that metabolize superoxide radicals to molecular oxygen and hydrogen peroxide or scavenge oxygen radicals produced by the extensive oxidation-reduction and electron-transport reactions that occur in mitochondria. We characterized SOD1 and SOD2 of Bombyx mori isolated from the fat body of larvae. Immunological analysis demonstrated the presence of BmSOD1 and BmSOD2 in the silk gland, midgut, fat body, Malpighian tubules, testis and ovary from larvae to adults. We found that BmSOD2 had a unique expression pattern in the fat body through the fifth instar larval developmental stage. The anti-oxidative functions of BmSOD1 and BmSOD2 were assessed by exposing larvae to insecticide rotenone or vasodilator isosorbide dinitrate, which is an ROS generator in BmN4 cells; however, exposure to these compounds had no effect on the expression levels of either BmSOD protein. Next, we investigated the physiological role of BmSOD1 and BmSOD2 under environmental oxidative stress, applied through whole-body UV irradiation and assayed using quantitative RT-PCR, immunoblotting and microarray analysis. The mRNA expression level of both BmSOD1 and BmSOD2 was markedly increased but protein expression level was increased only slightly. To examine the differences in mRNA and protein level due to UV irradiation intensity, we performed microarray analysis. Gene set enrichment analysis revealed that genes in the insulin signaling pathway and PPAR signaling pathway were significantly up-regulated after 6 and 12 hours of UV irradiation. Taken together, the activities of BmSOD1 and BmSOD2 may be related to the response to UV irradiation stress in B. mori. These results suggest that BmSOD1 and BmSOD2 modulate environmental oxidative stress in the cell and have a specific role in fat body of B. mori during pupation.

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Relative BmSOD1 and BmSOD2 protein levels in the fat body of fifth instar larvae.Relative expression levels (mean±SE; n = 3) of both BmSOD proteins plotted as a line graph (A) based on aliquots (10 μg) of protein samples from the fat body in day 0 to 6 fifth instar larvae, and SDS-PAGE with anti-SOD1 and anti-SOD2 antibodies for fifth instar larvae (B) at day 0 (lane 1), day 1 (lane 2), day 2 (lane 3), day 3 (lane 4), day 4 (lane 5), day 5 (lane 6) and day 6 (lane 7). Statistically significant differences against day 0 values determined by Student’s t-test are indicated as *, P<0.05 and ***, P<0.001.
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pone.0116007.g005: Relative BmSOD1 and BmSOD2 protein levels in the fat body of fifth instar larvae.Relative expression levels (mean±SE; n = 3) of both BmSOD proteins plotted as a line graph (A) based on aliquots (10 μg) of protein samples from the fat body in day 0 to 6 fifth instar larvae, and SDS-PAGE with anti-SOD1 and anti-SOD2 antibodies for fifth instar larvae (B) at day 0 (lane 1), day 1 (lane 2), day 2 (lane 3), day 3 (lane 4), day 4 (lane 5), day 5 (lane 6) and day 6 (lane 7). Statistically significant differences against day 0 values determined by Student’s t-test are indicated as *, P<0.05 and ***, P<0.001.

Mentions: Distribution of BmSOD1 protein and BmSOD2 protein expression by developmental stage and tissue is shown in Fig. 4. Both BmSOD proteins were expressed in the whole body through all developmental stages (Fig. 4 and S2-A Fig.). In addition, BmSOD proteins were expressed in various tissues from day 3 fifth instar larvae, but BmSOD2 protein expression levels were higher in the midgut and Malpighian tubules than in other tissues (Fig. 4 and S2-B Fig.). To determine the distribution pattern of BmSODs, we studied the fat body from day 0 to 6 fifth instar larvae by immunoblotting. BmSOD proteins were expressed throughout the larval developmental stages in the fat body, but BmSOD2 protein expression was low in day 1 and 6 fifth instar larvae (Fig. 5-A, B and S3 Fig.).


Superoxide dismutases, SOD1 and SOD2, play a distinct role in the fat body during pupation in silkworm Bombyx mori.

Nojima Y, Ito K, Ono H, Nakazato T, Bono H, Yokoyama T, Sato R, Suetsugu Y, Nakamura Y, Yamamoto K, Satoh J, Tabunoki H, Fugo H - PLoS ONE (2015)

Relative BmSOD1 and BmSOD2 protein levels in the fat body of fifth instar larvae.Relative expression levels (mean±SE; n = 3) of both BmSOD proteins plotted as a line graph (A) based on aliquots (10 μg) of protein samples from the fat body in day 0 to 6 fifth instar larvae, and SDS-PAGE with anti-SOD1 and anti-SOD2 antibodies for fifth instar larvae (B) at day 0 (lane 1), day 1 (lane 2), day 2 (lane 3), day 3 (lane 4), day 4 (lane 5), day 5 (lane 6) and day 6 (lane 7). Statistically significant differences against day 0 values determined by Student’s t-test are indicated as *, P<0.05 and ***, P<0.001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340916&req=5

pone.0116007.g005: Relative BmSOD1 and BmSOD2 protein levels in the fat body of fifth instar larvae.Relative expression levels (mean±SE; n = 3) of both BmSOD proteins plotted as a line graph (A) based on aliquots (10 μg) of protein samples from the fat body in day 0 to 6 fifth instar larvae, and SDS-PAGE with anti-SOD1 and anti-SOD2 antibodies for fifth instar larvae (B) at day 0 (lane 1), day 1 (lane 2), day 2 (lane 3), day 3 (lane 4), day 4 (lane 5), day 5 (lane 6) and day 6 (lane 7). Statistically significant differences against day 0 values determined by Student’s t-test are indicated as *, P<0.05 and ***, P<0.001.
Mentions: Distribution of BmSOD1 protein and BmSOD2 protein expression by developmental stage and tissue is shown in Fig. 4. Both BmSOD proteins were expressed in the whole body through all developmental stages (Fig. 4 and S2-A Fig.). In addition, BmSOD proteins were expressed in various tissues from day 3 fifth instar larvae, but BmSOD2 protein expression levels were higher in the midgut and Malpighian tubules than in other tissues (Fig. 4 and S2-B Fig.). To determine the distribution pattern of BmSODs, we studied the fat body from day 0 to 6 fifth instar larvae by immunoblotting. BmSOD proteins were expressed throughout the larval developmental stages in the fat body, but BmSOD2 protein expression was low in day 1 and 6 fifth instar larvae (Fig. 5-A, B and S3 Fig.).

Bottom Line: One way that aerobic biological systems counteract the generation of reactive oxygen species (ROS) is with superoxide dismutase proteins SOD1 and SOD2 that metabolize superoxide radicals to molecular oxygen and hydrogen peroxide or scavenge oxygen radicals produced by the extensive oxidation-reduction and electron-transport reactions that occur in mitochondria.We found that BmSOD2 had a unique expression pattern in the fat body through the fifth instar larval developmental stage.These results suggest that BmSOD1 and BmSOD2 modulate environmental oxidative stress in the cell and have a specific role in fat body of B. mori during pupation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan; Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Noshio, 2-522-1, Kiyose, Tokyo 204-8588, Japan.

ABSTRACT
One way that aerobic biological systems counteract the generation of reactive oxygen species (ROS) is with superoxide dismutase proteins SOD1 and SOD2 that metabolize superoxide radicals to molecular oxygen and hydrogen peroxide or scavenge oxygen radicals produced by the extensive oxidation-reduction and electron-transport reactions that occur in mitochondria. We characterized SOD1 and SOD2 of Bombyx mori isolated from the fat body of larvae. Immunological analysis demonstrated the presence of BmSOD1 and BmSOD2 in the silk gland, midgut, fat body, Malpighian tubules, testis and ovary from larvae to adults. We found that BmSOD2 had a unique expression pattern in the fat body through the fifth instar larval developmental stage. The anti-oxidative functions of BmSOD1 and BmSOD2 were assessed by exposing larvae to insecticide rotenone or vasodilator isosorbide dinitrate, which is an ROS generator in BmN4 cells; however, exposure to these compounds had no effect on the expression levels of either BmSOD protein. Next, we investigated the physiological role of BmSOD1 and BmSOD2 under environmental oxidative stress, applied through whole-body UV irradiation and assayed using quantitative RT-PCR, immunoblotting and microarray analysis. The mRNA expression level of both BmSOD1 and BmSOD2 was markedly increased but protein expression level was increased only slightly. To examine the differences in mRNA and protein level due to UV irradiation intensity, we performed microarray analysis. Gene set enrichment analysis revealed that genes in the insulin signaling pathway and PPAR signaling pathway were significantly up-regulated after 6 and 12 hours of UV irradiation. Taken together, the activities of BmSOD1 and BmSOD2 may be related to the response to UV irradiation stress in B. mori. These results suggest that BmSOD1 and BmSOD2 modulate environmental oxidative stress in the cell and have a specific role in fat body of B. mori during pupation.

Show MeSH
Related in: MedlinePlus