Yale scientists have discovered the molecular pathway by which maternally inherited deafness appears to occur: Mitochondrial DNA mutations trigger a signaling cascade, resulting in programmed cell death. The study is in the Feb. 17 issue of Cell.
Mitochondria are cellular structures that function as “cellular power plants” because they generate most of the cell’s supply of energy. They contain DNA inherited from one’s mother. Mitochondria determine whether a cell lives or dies via the process of programmed cell death, or apoptosis. (more…)
In 2005, news first broke that researchers in Scotland found unexpectedly low rates of cancer among diabetics taking metformin, a drug commonly prescribed to patients with Type II diabetes. Many follow-up studies reported similar findings, some suggesting as much as a 50-per-cent reduction in risk. How could this anti-diabetic drug reduce the risk of developing cancer and what were the mechanisms involved?
In a paper published today in the journal Cancer Prevention Research, researchers from McGill University and the University of Montreal reported an unexpected finding: they learned that exposure to metformin reduces the cellular mutation rate and the accumulation of DNA damage. It is well known that such mutations are directly involved in carcinogenesis, but lowering cancer risk by inhibiting the mutation rate has never been shown to be feasible. (more…)
Human pluripotent stem cells, which can develop into any cell type in the body, rely heavily on glycolysis, or sugar fermentation, to drive their metabolic activities.
In contrast, mature cells in children and adults depend more on cell mitochondria to convert sugar and oxygen into carbon dioxide and water during a high energy–producing process called oxidative phosphorylation. (more…)
Billions of years ago, an astounding evolutionary event occurred: certain bacteria became obliged to live inside other cells, thus starting a chain of events that resulted in what is now the mitochondria, an organelle found in all eukaryotic cells. A recent study by researchers at the University of Hawaiʻi at Mānoa and the Oregon State University (OSU) provides strong evidence that mitochondria share a common evolutionary ancestor with a lineage of marine bacteria known as SAR11, arguably the most abundant group of microorganisms on Earth.
“This is a very exciting discovery,” said Michael Rappe, Associate Researcher at the Hawaiʻi Institute of Marine Biology in the School of Ocean and Earth Science and Technology (SOEST) at UH Mānoa. “The results that we present make sense in a lot of ways: the physiology of SAR11 makes them more apt to be dependent on other organisms, and based on the contemporary abundance of SAR11 in the global ocean, the ancestral lineage may have also been abundant in the ancient ocean, increasing encounters between this bacterial lineage with the host of the original symbiosis event.” (more…)
