Limits...
Age-related micro-RNA abundance in individual C. elegans.

Lucanic M, Graham J, Scott G, Bhaumik D, Benz CC, Hubbard A, Lithgow GJ, Melov S - Aging (Albany NY) (2013)

Bottom Line: To identify expression differences associated with either reproductive or somatic tissues, we analyzed wild type and mutants that lacked germlines. miRNAs from the mir-35-41 cluster increased in abundance with age in wild type animals, but were nearly absent from mutants lacking a germline, suggesting their age-related increase originates from the germline.Most miRNAs with age-dependent levels did not have a major effect on lifespan, as corresponding deletion mutants exhibited wild-type lifespans.Our genetic characterization indicates that mir-71 acts at least partly in parallel to insulin/IGF like signals to influence lifespan.

View Article: PubMed Central - PubMed

Affiliation: Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945, USA. mlucanic@buckinstitute.org

ABSTRACT
Non-coding small RNAs of the micro-RNA class (miRNA) are conserved regulators of gene function with a broad impact on biological processes. We screened miRNA levels for age-related changes in individual worms and investigated their influence on the lifespan of the nematode C. elegans. We measured the abundance of 69 miRNAs expressed in individual animals at different ages with over thirty five thousand discrete quantitative nano-fluidic polymerase chain reactions. We found that miRNA abundance was highly variable between individual worms raised under identical conditions and that expression variability generally increased with age. To identify expression differences associated with either reproductive or somatic tissues, we analyzed wild type and mutants that lacked germlines. miRNAs from the mir-35-41 cluster increased in abundance with age in wild type animals, but were nearly absent from mutants lacking a germline, suggesting their age-related increase originates from the germline. Most miRNAs with age-dependent levels did not have a major effect on lifespan, as corresponding deletion mutants exhibited wild-type lifespans. The major exception to this was mir-71, which increased in abundance with age and was required for normal longevity. Our genetic characterization indicates that mir-71 acts at least partly in parallel to insulin/IGF like signals to influence lifespan.

Show MeSH

Related in: MedlinePlus

mir-71 acts at least partly in parallel to the IIS pathway(A) The integrated transgene maIs352[Pmir-71::mir-71::GFP] partially rescues the lifespan of mir-71  mutants. (B) The longevity phenotype of daf-2(e1368) is significantly suppressed by the presence of the mir-71(n4115) deletion. (C) daf-16; mir-71 double  mutants show significant enhancement relative to the single mutants. (D) Over-expression of mir-71 extends the lifespan of daf-16  mutants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3824409&req=5

Figure 4: mir-71 acts at least partly in parallel to the IIS pathway(A) The integrated transgene maIs352[Pmir-71::mir-71::GFP] partially rescues the lifespan of mir-71 mutants. (B) The longevity phenotype of daf-2(e1368) is significantly suppressed by the presence of the mir-71(n4115) deletion. (C) daf-16; mir-71 double mutants show significant enhancement relative to the single mutants. (D) Over-expression of mir-71 extends the lifespan of daf-16 mutants.

Mentions: In order to test whether miRNAs displaying age-specific abundance modulate lifespan, we tested mutant strains for several of the candidate miRNAs. These mutants were directly assayed for their lifespan and were compared to wild type animals (Supplemental Table 3). Of these, we found that one mutant strain carrying a deletion resulting in the removal of several miRNAs led to a weak lifespan extension. Specifically the deletion nDf48 that removes mir-42-44 led to a small but significant lifespan extension. (Supplemental Table 3), suggesting that individually or collectively these miRNAs may inhibit longevity in wild-type animals. We have also identified single miRNA mutations that resulted in mild or inconsistent lifespan phenotypes. The mir-80 allele nDf53 had a weak but significantly extended lifespan (Supplemental Table 3), while the mir-228(n4382) mutant trended towards an extended lifespan (Supplemental Table 3). In addition to miRNA mutants that showed an extended lifespan, we identified miRNA mutants that had shortened lifespans. We found that the mir-71 deletion n4115 had a profoundly shortened lifespan compared to wild type (Figure 4 and Supplemental Table 3), while the mir-60 deletion, n4947 trended towards shortened lifespan but was not consistently significantly different from wild type (Supplemental Table 3).


Age-related micro-RNA abundance in individual C. elegans.

Lucanic M, Graham J, Scott G, Bhaumik D, Benz CC, Hubbard A, Lithgow GJ, Melov S - Aging (Albany NY) (2013)

mir-71 acts at least partly in parallel to the IIS pathway(A) The integrated transgene maIs352[Pmir-71::mir-71::GFP] partially rescues the lifespan of mir-71  mutants. (B) The longevity phenotype of daf-2(e1368) is significantly suppressed by the presence of the mir-71(n4115) deletion. (C) daf-16; mir-71 double  mutants show significant enhancement relative to the single mutants. (D) Over-expression of mir-71 extends the lifespan of daf-16  mutants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824409&req=5

Figure 4: mir-71 acts at least partly in parallel to the IIS pathway(A) The integrated transgene maIs352[Pmir-71::mir-71::GFP] partially rescues the lifespan of mir-71 mutants. (B) The longevity phenotype of daf-2(e1368) is significantly suppressed by the presence of the mir-71(n4115) deletion. (C) daf-16; mir-71 double mutants show significant enhancement relative to the single mutants. (D) Over-expression of mir-71 extends the lifespan of daf-16 mutants.
Mentions: In order to test whether miRNAs displaying age-specific abundance modulate lifespan, we tested mutant strains for several of the candidate miRNAs. These mutants were directly assayed for their lifespan and were compared to wild type animals (Supplemental Table 3). Of these, we found that one mutant strain carrying a deletion resulting in the removal of several miRNAs led to a weak lifespan extension. Specifically the deletion nDf48 that removes mir-42-44 led to a small but significant lifespan extension. (Supplemental Table 3), suggesting that individually or collectively these miRNAs may inhibit longevity in wild-type animals. We have also identified single miRNA mutations that resulted in mild or inconsistent lifespan phenotypes. The mir-80 allele nDf53 had a weak but significantly extended lifespan (Supplemental Table 3), while the mir-228(n4382) mutant trended towards an extended lifespan (Supplemental Table 3). In addition to miRNA mutants that showed an extended lifespan, we identified miRNA mutants that had shortened lifespans. We found that the mir-71 deletion n4115 had a profoundly shortened lifespan compared to wild type (Figure 4 and Supplemental Table 3), while the mir-60 deletion, n4947 trended towards shortened lifespan but was not consistently significantly different from wild type (Supplemental Table 3).

Bottom Line: To identify expression differences associated with either reproductive or somatic tissues, we analyzed wild type and mutants that lacked germlines. miRNAs from the mir-35-41 cluster increased in abundance with age in wild type animals, but were nearly absent from mutants lacking a germline, suggesting their age-related increase originates from the germline.Most miRNAs with age-dependent levels did not have a major effect on lifespan, as corresponding deletion mutants exhibited wild-type lifespans.Our genetic characterization indicates that mir-71 acts at least partly in parallel to insulin/IGF like signals to influence lifespan.

View Article: PubMed Central - PubMed

Affiliation: Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945, USA. mlucanic@buckinstitute.org

ABSTRACT
Non-coding small RNAs of the micro-RNA class (miRNA) are conserved regulators of gene function with a broad impact on biological processes. We screened miRNA levels for age-related changes in individual worms and investigated their influence on the lifespan of the nematode C. elegans. We measured the abundance of 69 miRNAs expressed in individual animals at different ages with over thirty five thousand discrete quantitative nano-fluidic polymerase chain reactions. We found that miRNA abundance was highly variable between individual worms raised under identical conditions and that expression variability generally increased with age. To identify expression differences associated with either reproductive or somatic tissues, we analyzed wild type and mutants that lacked germlines. miRNAs from the mir-35-41 cluster increased in abundance with age in wild type animals, but were nearly absent from mutants lacking a germline, suggesting their age-related increase originates from the germline. Most miRNAs with age-dependent levels did not have a major effect on lifespan, as corresponding deletion mutants exhibited wild-type lifespans. The major exception to this was mir-71, which increased in abundance with age and was required for normal longevity. Our genetic characterization indicates that mir-71 acts at least partly in parallel to insulin/IGF like signals to influence lifespan.

Show MeSH
Related in: MedlinePlus