Biologists from the University of Manchester have explained for the first time why a good night's sleep can really prepare us for the rigors of the day ahead. The study shows how the body clock mechanism increases our ability to maintain our bodies when we are most active.
And because we know that the body clock is less accurate as we age, the discovery, lead author Professor Karl Kadler argues, claims it may one day help unlock some of the mysteries of aging.
The discovery sheds fascinating light on the body's extracellular matrix – which provides structural and biochemical support to cells in the form of connective tissues such as bone, skin, tendon and cartilage. More than half of our body weight is matrix, and half of this is collagen – and scientists have long understood that it is fully formed by the time we reach age 17.
Two types of fibrils
But now the researchers have discovered that there are two types of fibrils:the rope-like structures of collagen that are woven through the cells to form tissues.
Thicker fibrils about 200 nanometers in diameter – a million million times smaller than a pinhead – are permanent and remain with us throughout our lives, unchanged from age 17.
But thinner fibrils of 50 nanometers, they say, are sacrificial and break when we subject the body to the rigors of the day, but replenish when we rest at night.
The collagen was observed by mass spectrometry and the mouse fibrils were observed using state-of-the-art volumetric electron microscopy every 4 h for 2 days. When the body clock genes were turned off in mice, the thin and thick fibrils were randomly merged.
“Collagen provides structure to the body and is our most abundant protein, ensuring the integrity, elasticity and strength of the body's connective tissue,” said Professor Kadler
“It's intuitive to think that our matrix must be worn out by wear and tear, but it isn't and now we know why:our body clock makes an element that is sacrificial and can be replenished, protecting the permanent parts of the matrix.
He added:“So if you imagine the bricks in the walls of a room as the permanent part, the paint on the walls can be seen as the sacrificial part that needs to be topped up every so often.
“And just like you need to oil a car and keep the radiator filled with water, these thin fibrils help maintain the body's matrix.”
“Knowing this could have implications for understanding our biology at the most fundamental level. For example, it can give us a deeper understanding of how wounds heal, or how we age.
