Limits...
Proteins of nucleotide and base excision repair pathways interact in mitochondria to protect from loss of subcutaneous fat, a hallmark of aging.

Kamenisch Y, Fousteri M, Knoch J, von Thaler AK, Fehrenbacher B, Kato H, Becker T, Dollé ME, Kuiper R, Majora M, Schaller M, van der Horst GT, van Steeg H, Röcken M, Rapaport D, Krutmann J, Mullenders LH, Berneburg M - J. Exp. Med. (2010)

Bottom Line: We show functional increase of CSA and CSB inside mt and complex formation with mtDNA, mt human 8-oxoguanine glycosylase (mtOGG)-1, and mt single-stranded DNA binding protein (mtSSBP)-1 upon oxidative stress.MtDNA mutations are highly increased in cells from CS patients and in subcutaneous fat of aged Csb(m/m) and Csa(-/-) mice.Thus, the NER-proteins CSA and CSB localize to mt and directly interact with BER-associated human mitochondrial 8-oxoguanine glycosylase-1 to protect from aging- and stress-induced mtDNA mutations and apoptosis-mediated loss of subcutaneous fat, a hallmark of aging found in animal models, human progeroid syndromes like CS and in normal human aging.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Dermatology, Eberhard Karls University, D-72076 Tuebingen, Germany.

ABSTRACT
Defects in the DNA repair mechanism nucleotide excision repair (NER) may lead to tumors in xeroderma pigmentosum (XP) or to premature aging with loss of subcutaneous fat in Cockayne syndrome (CS). Mutations of mitochondrial (mt)DNA play a role in aging, but a link between the NER-associated CS proteins and base excision repair (BER)-associated proteins in mitochondrial aging remains enigmatic. We show functional increase of CSA and CSB inside mt and complex formation with mtDNA, mt human 8-oxoguanine glycosylase (mtOGG)-1, and mt single-stranded DNA binding protein (mtSSBP)-1 upon oxidative stress. MtDNA mutations are highly increased in cells from CS patients and in subcutaneous fat of aged Csb(m/m) and Csa(-/-) mice. Thus, the NER-proteins CSA and CSB localize to mt and directly interact with BER-associated human mitochondrial 8-oxoguanine glycosylase-1 to protect from aging- and stress-induced mtDNA mutations and apoptosis-mediated loss of subcutaneous fat, a hallmark of aging found in animal models, human progeroid syndromes like CS and in normal human aging.

Show MeSH

Related in: MedlinePlus

Age dependent accumulation of mtDNA mutations in subcutaneous fat tissue of Csbm/m and Csa−/− mice. (A) Subcutaneous fat tissue from WT mice and mice lacking a functional Csb or the Xpa gene were assessed for a frequent mouse-mtDNA deletion (D17). Three age groups (13, 5, and 130 wk, 4 mice per group) of each genotype were investigated. Aged Csbm/m mice show a strong increase of D17 in subcutaneous fat compared with WT or Xpa−/− controls (Student's t test, P < 0.01). Each PCR experiment was repeated independently two times. (B) Hematoxylin and eosin–stained cross sections with reduced subcutaneous fat tissue in old Csbm/m mice aged for 130 wk. Bar, 200 µm. (C) Measurement of D17 deletion in subcutaneous fat of WT, Csa−/− and XpdTTD/TTD mice similar to A. Each PCR experiment was repeated independently two times. (D) Restriction digest of PCR product of deletion D17 with EcoRV. (left) Undigested fragment of 850 bp. (right) EcoRV digest leading to fragments of 570 and 280 bp. Data are given as representative of at least three independent experiments.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC2822596&req=5

fig4: Age dependent accumulation of mtDNA mutations in subcutaneous fat tissue of Csbm/m and Csa−/− mice. (A) Subcutaneous fat tissue from WT mice and mice lacking a functional Csb or the Xpa gene were assessed for a frequent mouse-mtDNA deletion (D17). Three age groups (13, 5, and 130 wk, 4 mice per group) of each genotype were investigated. Aged Csbm/m mice show a strong increase of D17 in subcutaneous fat compared with WT or Xpa−/− controls (Student's t test, P < 0.01). Each PCR experiment was repeated independently two times. (B) Hematoxylin and eosin–stained cross sections with reduced subcutaneous fat tissue in old Csbm/m mice aged for 130 wk. Bar, 200 µm. (C) Measurement of D17 deletion in subcutaneous fat of WT, Csa−/− and XpdTTD/TTD mice similar to A. Each PCR experiment was repeated independently two times. (D) Restriction digest of PCR product of deletion D17 with EcoRV. (left) Undigested fragment of 850 bp. (right) EcoRV digest leading to fragments of 570 and 280 bp. Data are given as representative of at least three independent experiments.

Mentions: Photosensitivity of CS patients is currently explained by the known deficiency of CS cells in TC-NER. However, other age-associated symptoms such as reduced subcutaneous fat tissue cannot readily be deduced from this. To investigate whether mtDNA mutations are associated with this particular progeroid symptom in vivo, microdissected subcutaneous fat tissue from mice lacking the functional Csb or Xpa gene were assessed for the present levels of the most frequent mouse-mtDNA deletion in comparison to WT littermate controls, depending on their respective ages. Tissues from mice aged 13, 52, and 130 wk were investigated. Overall, there was an age-dependent accumulation of mtDNA mutations in all mice investigated. In addition to this, the Csbm/m mice show a strong increase of the mtDNA deletion in subcutaneous fat tissue of aged mice that exceeded levels of 60% in all Csbm/m animals (Fig. 4 A). This effect was highly significant (P < 0.01, Student's t test) when comparing Csbm/m with WT and Xpa−/− mice at 130 wk of age. Morphologically, this correlated with reduced subcutaneous fat tissue in histological sections of Csbm/m mice at the age of 130 wk (Fig. 4 B), whereas WT and Xpa−/− animals did not show this phenotype.


Proteins of nucleotide and base excision repair pathways interact in mitochondria to protect from loss of subcutaneous fat, a hallmark of aging.

Kamenisch Y, Fousteri M, Knoch J, von Thaler AK, Fehrenbacher B, Kato H, Becker T, Dollé ME, Kuiper R, Majora M, Schaller M, van der Horst GT, van Steeg H, Röcken M, Rapaport D, Krutmann J, Mullenders LH, Berneburg M - J. Exp. Med. (2010)

Age dependent accumulation of mtDNA mutations in subcutaneous fat tissue of Csbm/m and Csa−/− mice. (A) Subcutaneous fat tissue from WT mice and mice lacking a functional Csb or the Xpa gene were assessed for a frequent mouse-mtDNA deletion (D17). Three age groups (13, 5, and 130 wk, 4 mice per group) of each genotype were investigated. Aged Csbm/m mice show a strong increase of D17 in subcutaneous fat compared with WT or Xpa−/− controls (Student's t test, P < 0.01). Each PCR experiment was repeated independently two times. (B) Hematoxylin and eosin–stained cross sections with reduced subcutaneous fat tissue in old Csbm/m mice aged for 130 wk. Bar, 200 µm. (C) Measurement of D17 deletion in subcutaneous fat of WT, Csa−/− and XpdTTD/TTD mice similar to A. Each PCR experiment was repeated independently two times. (D) Restriction digest of PCR product of deletion D17 with EcoRV. (left) Undigested fragment of 850 bp. (right) EcoRV digest leading to fragments of 570 and 280 bp. Data are given as representative of at least three independent experiments.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2822596&req=5

fig4: Age dependent accumulation of mtDNA mutations in subcutaneous fat tissue of Csbm/m and Csa−/− mice. (A) Subcutaneous fat tissue from WT mice and mice lacking a functional Csb or the Xpa gene were assessed for a frequent mouse-mtDNA deletion (D17). Three age groups (13, 5, and 130 wk, 4 mice per group) of each genotype were investigated. Aged Csbm/m mice show a strong increase of D17 in subcutaneous fat compared with WT or Xpa−/− controls (Student's t test, P < 0.01). Each PCR experiment was repeated independently two times. (B) Hematoxylin and eosin–stained cross sections with reduced subcutaneous fat tissue in old Csbm/m mice aged for 130 wk. Bar, 200 µm. (C) Measurement of D17 deletion in subcutaneous fat of WT, Csa−/− and XpdTTD/TTD mice similar to A. Each PCR experiment was repeated independently two times. (D) Restriction digest of PCR product of deletion D17 with EcoRV. (left) Undigested fragment of 850 bp. (right) EcoRV digest leading to fragments of 570 and 280 bp. Data are given as representative of at least three independent experiments.
Mentions: Photosensitivity of CS patients is currently explained by the known deficiency of CS cells in TC-NER. However, other age-associated symptoms such as reduced subcutaneous fat tissue cannot readily be deduced from this. To investigate whether mtDNA mutations are associated with this particular progeroid symptom in vivo, microdissected subcutaneous fat tissue from mice lacking the functional Csb or Xpa gene were assessed for the present levels of the most frequent mouse-mtDNA deletion in comparison to WT littermate controls, depending on their respective ages. Tissues from mice aged 13, 52, and 130 wk were investigated. Overall, there was an age-dependent accumulation of mtDNA mutations in all mice investigated. In addition to this, the Csbm/m mice show a strong increase of the mtDNA deletion in subcutaneous fat tissue of aged mice that exceeded levels of 60% in all Csbm/m animals (Fig. 4 A). This effect was highly significant (P < 0.01, Student's t test) when comparing Csbm/m with WT and Xpa−/− mice at 130 wk of age. Morphologically, this correlated with reduced subcutaneous fat tissue in histological sections of Csbm/m mice at the age of 130 wk (Fig. 4 B), whereas WT and Xpa−/− animals did not show this phenotype.

Bottom Line: We show functional increase of CSA and CSB inside mt and complex formation with mtDNA, mt human 8-oxoguanine glycosylase (mtOGG)-1, and mt single-stranded DNA binding protein (mtSSBP)-1 upon oxidative stress.MtDNA mutations are highly increased in cells from CS patients and in subcutaneous fat of aged Csb(m/m) and Csa(-/-) mice.Thus, the NER-proteins CSA and CSB localize to mt and directly interact with BER-associated human mitochondrial 8-oxoguanine glycosylase-1 to protect from aging- and stress-induced mtDNA mutations and apoptosis-mediated loss of subcutaneous fat, a hallmark of aging found in animal models, human progeroid syndromes like CS and in normal human aging.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Dermatology, Eberhard Karls University, D-72076 Tuebingen, Germany.

ABSTRACT
Defects in the DNA repair mechanism nucleotide excision repair (NER) may lead to tumors in xeroderma pigmentosum (XP) or to premature aging with loss of subcutaneous fat in Cockayne syndrome (CS). Mutations of mitochondrial (mt)DNA play a role in aging, but a link between the NER-associated CS proteins and base excision repair (BER)-associated proteins in mitochondrial aging remains enigmatic. We show functional increase of CSA and CSB inside mt and complex formation with mtDNA, mt human 8-oxoguanine glycosylase (mtOGG)-1, and mt single-stranded DNA binding protein (mtSSBP)-1 upon oxidative stress. MtDNA mutations are highly increased in cells from CS patients and in subcutaneous fat of aged Csb(m/m) and Csa(-/-) mice. Thus, the NER-proteins CSA and CSB localize to mt and directly interact with BER-associated human mitochondrial 8-oxoguanine glycosylase-1 to protect from aging- and stress-induced mtDNA mutations and apoptosis-mediated loss of subcutaneous fat, a hallmark of aging found in animal models, human progeroid syndromes like CS and in normal human aging.

Show MeSH
Related in: MedlinePlus