Neki dijelovi vašeg tijela stariju brže od drugih, otkriva izraelska studija

Some parts of your body age faster than others, Israeli researchers have discovered, challenging long-held assumptions about the uniformity of aging. A groundbreaking study conducted by scientists at the Hebrew University of Jerusalem (HUJI) and the Hadassah University Medical Center has revealed that individual cells within the human body age at varying rates, with certain cells showing signs of accelerated biological aging. Published in the prestigious scientific journal Nature Communications, the study titled “Cell-to-cell variability and gain of methylation at polycomb CpG islands as a hallmark of aging” offers a new perspective on how aging occurs at the cellular level. The research, led by Prof. Howard Cedar, a renowned biochemist known for his pioneering work in DNA methylation, suggests that aging is not a synchronized process across all tissues. Instead, specific cells, particularly those in organs such as the liver, brain, and skin, exhibit greater signs of biological aging compared to others. These findings could lead to breakthroughs in developing therapies aimed at slowing the overall aging process rather than focusing solely on treating age-related diseases like cancer, Alzheimer's, or cardiovascular conditions. DNA methylation, a key molecular process studied by Cedar and his team, plays a central role in regulating gene expression. This process involves adding a methyl group, a small molecule consisting of one carbon atom and three hydrogen atoms, to DNA strands. This addition acts as a kind of dimmer switch, controlling whether genes are activated or silenced without altering the actual sequence of the genetic code. The study found that variations in DNA methylation patterns among cells can serve as markers of biological age, indicating which cells are aging more rapidly. Prof. Cedar explained that while chronological age, the number of years someone has lived, is a standard measure, biological age reflects the functional state of cells. His team discovered that even within the same organ, cells differ significantly in their rate of aging. For example, some cells in the liver might show signs of being decades older than their counterparts in the same tissue. This uneven distribution of aging could contribute to the development of age-related illnesses, as damaged or aged cells may lose their ability to perform essential functions. The research also highlights the importance of understanding how environmental factors and lifestyle choices influence cellular aging. By identifying the molecular signatures associated with accelerated aging, scientists hope to create interventions that target these processes directly. Such treatments could potentially delay the onset of chronic diseases linked to aging, improving quality of life and extending healthy lifespan. Prof. Cedar, who was born in New York and later moved to Israel, has spent decades studying DNA methylation and its implications for health and disease. His early work focused on how genes are regulated during embryonic development, revealing how the same genetic blueprint can produce diverse cell types through differential gene expression. More recently, his attention has shifted toward the role of epigenetic changes, in particular, alterations in DNA methylation, in the progression of diseases like cancer. The study’s extensive methodology included analyzing thousands of samples from multiple tissues, using advanced sequencing techniques to map methylation patterns across the genome. The inclusion of over 112 detailed footnotes underscores the complexity of the research and the depth of analysis undertaken by the team. Their findings suggest that future medical strategies should consider the heterogeneity of aging at the cellular level, rather than assuming a uniform process. As the scientific community continues to explore the intricacies of aging, the implications of this study extend beyond basic science. Researchers are already considering how these insights might inform personalized medicine, where treatment plans could be tailored based on an individual’s unique pattern of cellular aging. This approach could revolutionize how we understand and manage the aging process, offering new hope for healthier, longer lives.