John Hemming's Web Log

Oxygen is essential for human life. That is well known. However, the level of Oxygen in the atmosphere has interesting effects. I wrote previously about The Hypoxia Inducible Factor (HIF). HIF (particularly 1 alpha) is a molecule which signals cells to create proteins to build in response to stress. This can involve building new mitochondria or recycling old inefficient mitochondria. In essence it is ringing an alarm that calls for cells to get better prepared for stress. Interestingly HIF is switched on by a drop in the oxygen partial pressure (that proportion of air pressure that is oxygen). It is also well known that if brain cells get too little Oxygen then they can get harmed or die. Hence too low an Oxygen level causes brain damage. In fact there is evidence from people living at high altitudes that at a point the oxygen level is too low and this harms health. However, there is another aspect of Oxygen levels that relates to the mitochondria. The mitochondria produc...

There are a number of theoretical debates about aging. One is the question of whether we are "programmed to die". Those who believe this think that at a point creatures get to a stage where the organism at a cellular level starts processes which deliberately set out to end the life of the multicellular organism. Another potentially contradictory view is simply that creatures accumulate damage up the point at which they can no longer survive. It is possible, however, to look at different species and see how their lifespan operates. What is clear is that different species age in different ways. Some species don't age in the same way as others. It is worth having a look at how species vary and to what extent that explains the relationship between evolution and lifespan. Firstly, it is clear that there are species where the adult commits some form of suicide after mating. Octopuses and Pacific Salmon There are, however, also species which have negligible senes...

An interesting paper was published in the week before Christmas. Mitochondrial quality control: the real dawn of intervertebral disc degeneration? The summary states: Intervertebral disc degeneration is the most common disease in chronic musculoskeletal diseases and the main cause of low back pain, which seriously endangers social health level and increases people’s economic burden. Disc degeneration is characterized by NP cell apoptosis, extracellular matrix degradation and disc structure changes. It progresses with age and under the influence of mechanical overload, oxidative stress and genetics. Mitochondria are not only the energy factories of cells, but also participate in a variety of cellular functions such as calcium homeostasis, regulation of cell proliferation, and control of apoptosis. The mitochondrial quality control system involves many mechanisms such as mitochondrial gene regulation, mitochondrial protein import, mitophagy, and mitochondrial dynamics. A large numbe...