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A Drosophila ABC transporter regulates lifespan.

Huang H, Lu-Bo Y, Haddad GG - PLoS Genet. (2014)

Bottom Line: MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes.By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition.We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America.

ABSTRACT
MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

No MeSH data available.


Related in: MedlinePlus

dMRP4 affects lifespan.(A) Lifespan of adult flies lacking dMRP4. Survival was presented as mean of at least 300 males with different genotypes. Homozygous dMRP4 mutant flies lived significantly shorter than their sibling controls (Log-rank test, p<0.0001): the mean lifespan (50% mortality) was 45 days for dMRP4M2/M2 and 45 days for dMRP4M2/M1, respectively, compared to 66 days for wild-type control (w1118); the maximum lifespan (90% mortality) was 63 for dMRP4M2/M2 and 60 days for dMRP4M2/M1, respectively, compared to 78 days for wild-type control. (B) Analysis of age-specific mortality. The log cumulative hazard plots were presented for different genotypes of survival data. The ratio of slopes from Partial Slopes Rank-Sum Test: w1118 vs dMRP4M1/M1 = 1.24 (p = 0.2005), w1118 vs dMRP4M2/M2 = 1.32 (p = 0.0947), dMRP4M1/M1 vs dMRP4M2/M2 = 1.07 (p = 0.7182). (C) Lifespan of adult flies with genotype tub5GS>dMRP4 (tubulin5-GS-Gal4/EP3177) between treatments: −RU486 group, mean = 64 days, maximum = 78 days (n = 383), +RU486 group (100 ug/ml), mean = 74 day, maximum = 84 (n = 427), and +RU486 group (20 ug/ml), mean = 70 days, maximum = 82 days (n = 438). The cohort was derived from a combination of two independent cohorts (about 200 flies for each cohort) which were conducted over different time periods, and the individual cohorts were similar to each other. (D) Effects of RU486 treatment on control groups. tub5GS-Gal4/+ (−RU486), mean = 62 days (n = 300) and tub5GS-Gal4/+ (+RU486 100 ug/ml), mean = 62 days (n = 300). (E) Lifespan of adult flies with genotype S106>dMRP4 (S106-Gal4/+; EP3177/+) between treatments: −RU486, mean = 60 days (n = 408), or +RU486, mean = 62 days (n = 460). (F) Effects of RU486 treatment on control groups. S106-Gal4/+ (−RU486), mean = 54 days (n = 300) and S106-Gal4/+ (+RU486 100 ug/ml), mean = 55 days (n = 300). (G) Lifespan of adult flies with genotype da>dMRP4 was compared to the parent controls. The mean lifespan of these flies was 62 days for da-Gal4/+ (n = 340), 61 days for dMRP4/+ (n = 320), and 45 days for da>dMRP4 (n = 380). The maximum lifespan was 77 days for da-Gal4/+, 77 days for dMRP4/+, and 56 days for da>dMRP4. (H) qt-PCR analysis of the dMRP4 expression driven by da-Gal4.
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pgen-1004844-g005: dMRP4 affects lifespan.(A) Lifespan of adult flies lacking dMRP4. Survival was presented as mean of at least 300 males with different genotypes. Homozygous dMRP4 mutant flies lived significantly shorter than their sibling controls (Log-rank test, p<0.0001): the mean lifespan (50% mortality) was 45 days for dMRP4M2/M2 and 45 days for dMRP4M2/M1, respectively, compared to 66 days for wild-type control (w1118); the maximum lifespan (90% mortality) was 63 for dMRP4M2/M2 and 60 days for dMRP4M2/M1, respectively, compared to 78 days for wild-type control. (B) Analysis of age-specific mortality. The log cumulative hazard plots were presented for different genotypes of survival data. The ratio of slopes from Partial Slopes Rank-Sum Test: w1118 vs dMRP4M1/M1 = 1.24 (p = 0.2005), w1118 vs dMRP4M2/M2 = 1.32 (p = 0.0947), dMRP4M1/M1 vs dMRP4M2/M2 = 1.07 (p = 0.7182). (C) Lifespan of adult flies with genotype tub5GS>dMRP4 (tubulin5-GS-Gal4/EP3177) between treatments: −RU486 group, mean = 64 days, maximum = 78 days (n = 383), +RU486 group (100 ug/ml), mean = 74 day, maximum = 84 (n = 427), and +RU486 group (20 ug/ml), mean = 70 days, maximum = 82 days (n = 438). The cohort was derived from a combination of two independent cohorts (about 200 flies for each cohort) which were conducted over different time periods, and the individual cohorts were similar to each other. (D) Effects of RU486 treatment on control groups. tub5GS-Gal4/+ (−RU486), mean = 62 days (n = 300) and tub5GS-Gal4/+ (+RU486 100 ug/ml), mean = 62 days (n = 300). (E) Lifespan of adult flies with genotype S106>dMRP4 (S106-Gal4/+; EP3177/+) between treatments: −RU486, mean = 60 days (n = 408), or +RU486, mean = 62 days (n = 460). (F) Effects of RU486 treatment on control groups. S106-Gal4/+ (−RU486), mean = 54 days (n = 300) and S106-Gal4/+ (+RU486 100 ug/ml), mean = 55 days (n = 300). (G) Lifespan of adult flies with genotype da>dMRP4 was compared to the parent controls. The mean lifespan of these flies was 62 days for da-Gal4/+ (n = 340), 61 days for dMRP4/+ (n = 320), and 45 days for da>dMRP4 (n = 380). The maximum lifespan was 77 days for da-Gal4/+, 77 days for dMRP4/+, and 56 days for da>dMRP4. (H) qt-PCR analysis of the dMRP4 expression driven by da-Gal4.

Mentions: Aging shares many features with oxidative stress [1]. The free radical theory has proposed a link between aging and oxidative stress [46], [47]. Recent studies from genetic manipulation of many genes in Drosophila have presented evidence that resistance to oxidative stress genetic often correlate with increased lifespan [6], [48], [49], [50]. Since manipulation of dMRP4 can influence lifespan under oxidative stress, it would be important to examine whether dMRP4 regulates lifespan under non-stress conditions. We observed that mutations in dMRP4 dramatically caused a shortened normal adult lifespan (Fig. 5A, Log-rank test, p<0.0001). In particular, dMRP4M2/M2 flies had a mean lifespan (as measured by 50% survival) of 45 days and a maximum lifespan (as measured by the 90 percent survival) of 60 days. Compared to wild-type controls, dMRP4M2/M2 flies had a major reduction in the mean lifespan of about 47% and a decrease in maximum lifespan of 24% (Fig. 5A). Similar results were observed with dMRP4M1/M1 flies (Fig. 5A). The overall mortality rates of these groups were compared using Partial Slopes Rank-Sum Test [51] over the linear portion of the increase in mortality. Despite an apparent initiation of early mortality before day 30 in survival of dMRP4 mutants, there was no significant difference in slopes between the mutants and wild type (Fig. 5B), indicating that loss of dMRP4 decreased lifespan by lowing the whole mortality trajectory, but not the rate of increase in mortality with age. Thus, although dMRP4 is not required for normal development, it is required for normal lifespan under non-stress conditions.


A Drosophila ABC transporter regulates lifespan.

Huang H, Lu-Bo Y, Haddad GG - PLoS Genet. (2014)

dMRP4 affects lifespan.(A) Lifespan of adult flies lacking dMRP4. Survival was presented as mean of at least 300 males with different genotypes. Homozygous dMRP4 mutant flies lived significantly shorter than their sibling controls (Log-rank test, p<0.0001): the mean lifespan (50% mortality) was 45 days for dMRP4M2/M2 and 45 days for dMRP4M2/M1, respectively, compared to 66 days for wild-type control (w1118); the maximum lifespan (90% mortality) was 63 for dMRP4M2/M2 and 60 days for dMRP4M2/M1, respectively, compared to 78 days for wild-type control. (B) Analysis of age-specific mortality. The log cumulative hazard plots were presented for different genotypes of survival data. The ratio of slopes from Partial Slopes Rank-Sum Test: w1118 vs dMRP4M1/M1 = 1.24 (p = 0.2005), w1118 vs dMRP4M2/M2 = 1.32 (p = 0.0947), dMRP4M1/M1 vs dMRP4M2/M2 = 1.07 (p = 0.7182). (C) Lifespan of adult flies with genotype tub5GS>dMRP4 (tubulin5-GS-Gal4/EP3177) between treatments: −RU486 group, mean = 64 days, maximum = 78 days (n = 383), +RU486 group (100 ug/ml), mean = 74 day, maximum = 84 (n = 427), and +RU486 group (20 ug/ml), mean = 70 days, maximum = 82 days (n = 438). The cohort was derived from a combination of two independent cohorts (about 200 flies for each cohort) which were conducted over different time periods, and the individual cohorts were similar to each other. (D) Effects of RU486 treatment on control groups. tub5GS-Gal4/+ (−RU486), mean = 62 days (n = 300) and tub5GS-Gal4/+ (+RU486 100 ug/ml), mean = 62 days (n = 300). (E) Lifespan of adult flies with genotype S106>dMRP4 (S106-Gal4/+; EP3177/+) between treatments: −RU486, mean = 60 days (n = 408), or +RU486, mean = 62 days (n = 460). (F) Effects of RU486 treatment on control groups. S106-Gal4/+ (−RU486), mean = 54 days (n = 300) and S106-Gal4/+ (+RU486 100 ug/ml), mean = 55 days (n = 300). (G) Lifespan of adult flies with genotype da>dMRP4 was compared to the parent controls. The mean lifespan of these flies was 62 days for da-Gal4/+ (n = 340), 61 days for dMRP4/+ (n = 320), and 45 days for da>dMRP4 (n = 380). The maximum lifespan was 77 days for da-Gal4/+, 77 days for dMRP4/+, and 56 days for da>dMRP4. (H) qt-PCR analysis of the dMRP4 expression driven by da-Gal4.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4256198&req=5

pgen-1004844-g005: dMRP4 affects lifespan.(A) Lifespan of adult flies lacking dMRP4. Survival was presented as mean of at least 300 males with different genotypes. Homozygous dMRP4 mutant flies lived significantly shorter than their sibling controls (Log-rank test, p<0.0001): the mean lifespan (50% mortality) was 45 days for dMRP4M2/M2 and 45 days for dMRP4M2/M1, respectively, compared to 66 days for wild-type control (w1118); the maximum lifespan (90% mortality) was 63 for dMRP4M2/M2 and 60 days for dMRP4M2/M1, respectively, compared to 78 days for wild-type control. (B) Analysis of age-specific mortality. The log cumulative hazard plots were presented for different genotypes of survival data. The ratio of slopes from Partial Slopes Rank-Sum Test: w1118 vs dMRP4M1/M1 = 1.24 (p = 0.2005), w1118 vs dMRP4M2/M2 = 1.32 (p = 0.0947), dMRP4M1/M1 vs dMRP4M2/M2 = 1.07 (p = 0.7182). (C) Lifespan of adult flies with genotype tub5GS>dMRP4 (tubulin5-GS-Gal4/EP3177) between treatments: −RU486 group, mean = 64 days, maximum = 78 days (n = 383), +RU486 group (100 ug/ml), mean = 74 day, maximum = 84 (n = 427), and +RU486 group (20 ug/ml), mean = 70 days, maximum = 82 days (n = 438). The cohort was derived from a combination of two independent cohorts (about 200 flies for each cohort) which were conducted over different time periods, and the individual cohorts were similar to each other. (D) Effects of RU486 treatment on control groups. tub5GS-Gal4/+ (−RU486), mean = 62 days (n = 300) and tub5GS-Gal4/+ (+RU486 100 ug/ml), mean = 62 days (n = 300). (E) Lifespan of adult flies with genotype S106>dMRP4 (S106-Gal4/+; EP3177/+) between treatments: −RU486, mean = 60 days (n = 408), or +RU486, mean = 62 days (n = 460). (F) Effects of RU486 treatment on control groups. S106-Gal4/+ (−RU486), mean = 54 days (n = 300) and S106-Gal4/+ (+RU486 100 ug/ml), mean = 55 days (n = 300). (G) Lifespan of adult flies with genotype da>dMRP4 was compared to the parent controls. The mean lifespan of these flies was 62 days for da-Gal4/+ (n = 340), 61 days for dMRP4/+ (n = 320), and 45 days for da>dMRP4 (n = 380). The maximum lifespan was 77 days for da-Gal4/+, 77 days for dMRP4/+, and 56 days for da>dMRP4. (H) qt-PCR analysis of the dMRP4 expression driven by da-Gal4.
Mentions: Aging shares many features with oxidative stress [1]. The free radical theory has proposed a link between aging and oxidative stress [46], [47]. Recent studies from genetic manipulation of many genes in Drosophila have presented evidence that resistance to oxidative stress genetic often correlate with increased lifespan [6], [48], [49], [50]. Since manipulation of dMRP4 can influence lifespan under oxidative stress, it would be important to examine whether dMRP4 regulates lifespan under non-stress conditions. We observed that mutations in dMRP4 dramatically caused a shortened normal adult lifespan (Fig. 5A, Log-rank test, p<0.0001). In particular, dMRP4M2/M2 flies had a mean lifespan (as measured by 50% survival) of 45 days and a maximum lifespan (as measured by the 90 percent survival) of 60 days. Compared to wild-type controls, dMRP4M2/M2 flies had a major reduction in the mean lifespan of about 47% and a decrease in maximum lifespan of 24% (Fig. 5A). Similar results were observed with dMRP4M1/M1 flies (Fig. 5A). The overall mortality rates of these groups were compared using Partial Slopes Rank-Sum Test [51] over the linear portion of the increase in mortality. Despite an apparent initiation of early mortality before day 30 in survival of dMRP4 mutants, there was no significant difference in slopes between the mutants and wild type (Fig. 5B), indicating that loss of dMRP4 decreased lifespan by lowing the whole mortality trajectory, but not the rate of increase in mortality with age. Thus, although dMRP4 is not required for normal development, it is required for normal lifespan under non-stress conditions.

Bottom Line: MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes.By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition.We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America.

ABSTRACT
MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

No MeSH data available.


Related in: MedlinePlus