Changed life course upon defective replication of ribosomal RNA genes.

Genes Genet Syst

Laboratory of Genome Regeneration, Institute for Quantitative Biosciences (IQB), The University of Tokyo.

Published: April 2023

Genome instability is a major cause of aging. In the budding yeast Saccharomyces cerevisiae, instability of the ribosomal RNA gene repeat (rDNA) is known to shorten replicative lifespan. In yeast, rDNA instability in an aging cell is associated with accumulation of extrachromosomal rDNA circles (ERCs) which titrate factors critical for lifespan maintenance. ERC accumulation is not detected in mammalian cells, where aging is linked to DNA damage. To distinguish effects of DNA damage from those of ERC accumulation on senescence, we re-analyzed a yeast strain with a replication initiation defect in the rDNA, which limits ERC multiplication. In aging cells of this strain (rARS-∆3) rDNA became unstable, as in wild-type cells, whereas significantly fewer ERCs accumulated. Single-cell aging analysis revealed that rARS-∆3 cells follow a linear survival curve and can have a wild-type replicative lifespan, although a fraction of the cells stopped dividing earlier than wild type. The doubling time of rARS-∆3 cells appears to increase in the final cell divisions. Our results suggest that senescence in rARS-∆3 is linked to the accumulation of DNA damage as in mammalian cells, rather than to elevated ERC level. Therefore, this strain should be a good model system to study ERC-independent aging.

Download full-text PDF

Source
http://dx.doi.org/10.1266/ggs.22-00100DOI Listing

Publication Analysis

Top Keywords

dna damage
12
ribosomal rna
8
replicative lifespan
8
erc accumulation
8
mammalian cells
8
rars-∆3 cells
8
cells
7
aging
6
rdna
5
changed life
4

Similar Publications

Short and long-term effects of experimental varicocele.

Andrology

January 2025

Department of Surgery, Division of Urology, Human Reproduction Section, São Paulo Federal University, São Paulo, Brazil.

Background: Varicocele is associated with a progressive decrease in male fertile potential, but it has yet to be determined if the duration of varicocele is associated with altered sperm functional quality.

Objectives: This experimental study investigated the time-dependent effects of varicocele on spermatogenesis, sperm parameters, and sperm functional traits.

Materials And Methods: Thirty-five mature male Wistar rats (200 ± 25 g) were included.

View Article and Find Full Text PDF

Long-term blood glucose control via glucose-activated transcriptional regulation of insulin analogue in type 1 diabetes mice.

Diabetes Obes Metab

January 2025

National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan, People's Republic of China.

Aim: To achieve glucose-activated transcriptional regulation of insulin analogue in skeletal muscle of T1D mice, thereby controlling blood glucose levels and preventing or mitigating diabetes-related complications.

Materials And Methods: We developed the GANIT (Glucose-Activated NFAT-regulated INSA-F Transcription) system, an innovative platform building upon the previously established intramuscular plasmid DNA (pDNA) delivery and expression system. In the GANIT system, skeletal muscle cells are genetically engineered to endogenously produce the insulin analogue INSA-F (Insulin Aspart with Furin cleavage sites).

View Article and Find Full Text PDF

Background And Hypothesis: Gut dysbiosis characterized by an imbalance in pathobionts (Enterobacter, Escherichia and Salmonella) and symbionts (Bifidobacterium, Lactobacillus and Prevotella) can occur during chronic kidney disease (CKD) progression. We evaluated the associations between representative symbionts (Bifidobacterium and Lactobacillus) and pathobionts (Enterobacteriaceae) with kidney function in persons with autosomal dominant polycystic kidney disease (ADPKD).

Methods: In this cross-sectional study, 29 ADPKD patients were matched to 15 controls at a 2:1 ratio.

View Article and Find Full Text PDF

This study presents a new highly sensitive and specific time-resolved fluoroimmunoassay (TRFIA) for the measurement of trace amounts of the urinary 8-hydroxy-2`-deoxyguanosine (8-OHdG) which is a biomarker for oxidative stress on DNA. The assay relied on a competitive binding approach and a mouse monoclonal antibody which recognized 8-OHdG with high specificity. In this assay, 8-OHdG conjugated with bovine serum albumin protein (8-OHdG-BSA) was employed as a solid phase antigen.

View Article and Find Full Text PDF

Background: Mitochondria generate the adenosine triphosphate (ATP) necessary for eukaryotic cells, serving as their primary energy suppliers, and contribute to host defense by producing reactive oxygen species. In many critical illnesses, including sepsis, major trauma, and heatstroke, the vicious cycle between activated coagulation and inflammation results in tissue hypoxia-induced mitochondrial dysfunction, and impaired mitochondrial function contributes to thromboinflammation and cell death.

Methods: A computer-based online search was performed using the PubMed and Web of Science databases for published articles concerning sepsis, trauma, critical illnesses, cell death, mitochondria, inflammation, coagulopathy, and organ dysfunction.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!