News | How can human eggs remain viable for decades? Study identifies a key mechanism
A study offers a new biological explanation for how human eggs remain viable for decades. Unlike most cells, eggs process metabolic waste very slowly, potentially reducing accumulated damage and enabling their exceptionally long lifespan.
All human eggs are formed by birth and may need to survive for about 50 years. Apart from some neural and visual-system cells, most cells are gradually damaged and replaced through continued metabolism. Protein renewal itself produces harmful byproducts.
"Cells use energy to recycle and degrade proteins, producing reactive oxygen species (ROS) that quietly damage them," explained Elvan Böke of Spain's Centre for Genomic Regulation (CRG). "This background damage is continuous, and more ROS means more damage."
To see how healthy eggs avoid this, Böke's team examined donated human eggs and used fluorescent dyes to mark lysosomes, the cell's "recycling plants" that break down discarded proteins.
Lysosomal activity was much lower than in other human cells and in eggs from small mammals such as mice. Gabriele Zaffagnini of the University of Cologne said this low-activity mode may protect eggs by reducing energy use, ROS production, and long-term wear.
Slower waste processing may be only one part of the strategy. Böke suggested human eggs may put the brakes on all cellular processes, reducing random damage to DNA and organelles and maintaining long-term stability.
Emre Seli of Yale School of Medicine said eggs that fail to slow protein degradation and metabolism may gradually lose function, offering a way to understand changes after a certain age.
Clinically, the mechanism may relate closely to fertility treatment. Böke said dysregulated protein degradation would "100 percent affect fertility." The team will compare healthy eggs with those from people experiencing infertility. High ROS levels in eggs are already associated with poor IVF outcomes.
Research faces difficulty obtaining samples, regulatory restrictions, and limited funding. Seli described these as multiple layers of obstacles.
Zaffagnini nevertheless said overcoming these barriers could reveal genuinely unexpected features of human egg biology and that the research is well worth continuing.
News | How can human eggs remain viable for decades? Study identifies a key mechanism
News | How can human eggs remain viable for decades? Study identifies a key mechanism
A study offers a new biological explanation for how human eggs remain viable for decades. Unlike most cells, eggs process metabolic waste very slowly, potentially reducing accumulated damage and enabling their exceptionally long lifespan.
All human eggs are formed by birth and may need to survive for about 50 years. Apart from some neural and visual-system cells, most cells are gradually damaged and replaced through continued metabolism. Protein renewal itself produces harmful byproducts.
"Cells use energy to recycle and degrade proteins, producing reactive oxygen species (ROS) that quietly damage them," explained Elvan Böke of Spain's Centre for Genomic Regulation (CRG). "This background damage is continuous, and more ROS means more damage."
To see how healthy eggs avoid this, Böke's team examined donated human eggs and used fluorescent dyes to mark lysosomes, the cell's "recycling plants" that break down discarded proteins.
Lysosomal activity was much lower than in other human cells and in eggs from small mammals such as mice. Gabriele Zaffagnini of the University of Cologne said this low-activity mode may protect eggs by reducing energy use, ROS production, and long-term wear.
Slower waste processing may be only one part of the strategy. Böke suggested human eggs may put the brakes on all cellular processes, reducing random damage to DNA and organelles and maintaining long-term stability.
Emre Seli of Yale School of Medicine said eggs that fail to slow protein degradation and metabolism may gradually lose function, offering a way to understand changes after a certain age.
Clinically, the mechanism may relate closely to fertility treatment. Böke said dysregulated protein degradation would "100 percent affect fertility." The team will compare healthy eggs with those from people experiencing infertility. High ROS levels in eggs are already associated with poor IVF outcomes.
Research faces difficulty obtaining samples, regulatory restrictions, and limited funding. Seli described these as multiple layers of obstacles.
Zaffagnini nevertheless said overcoming these barriers could reveal genuinely unexpected features of human egg biology and that the research is well worth continuing.
Story source:
Collected online