Growth factor and the unbearable darkness of vision

I read on PubMed about a new research, published in Aging cells, demonstrating that low-protein diet slows Alzheimer’s disease in mice.

Mice at advanced stages of Alzheimer’s disease were put on diet  of periodic protein restriction cycles with supplementation of non-essential amino acids for four months. They showed improved cognitive abilities over their non-dieting peers. In addition, fewer of their neurons contained abnormal levels of a damaged protein, called “tau,” which accumulates in the brains of Alzheimer’s patients.

Protein restriction diets reduce insulin -like growth factor (IGF-1) and phosphorylated Tau, and improve behavioural performance in an Alzheimer’s disease mouse model. The team found that a protein-restricted diet reduced levels of IGF-1 circulating through the body by 30 to 70 per cent, and caused an eight-fold increase in a protein that blocks IGF-1′s effects by binding to it.

IGF-1 helps the body grow during youth but is also associated with several diseases later in life in both mice and humans. It had previously been shown that humans deficient in Growth Hormone receptor and IGF-I displayed reduced incidence of cancer and diabetes.


Another research on Hepatocyte growth factor (HGF), published in PLos Genetics, showed that a growth factor could be used as a drug for emphysema. Emphysema is a form of chronic obstructive pulmonary disease (COPD), which is the third-leading cause of death in the United States. No treatments are currently available that can regenerate the airspace once damaged.

Growth factors, such as HGF, have been used to promote wound healing. Previous studies had shown that HGF had a role in the functioning of alveoli, which enable lungs to exchange oxygen and carbon dioxide and send oxygen into the bloodstream.

The authors wanted  to determine whether hepatocyte growth factor HGF, which is a small cell-signalling protein regulator cytokine, that takes part in the alveolar formation (epithelial proliferation, migration, resistance from apoptosis and angiogenesis), could be an important mediator of alveolar formation and airspace maintenance.

The researchers found that the mice with emphysema, when given the hepatocyte growth factor HGF, developed a 17 per cent improvement in the size of their air sacs, compared to placebo-treated mice, consistent with improved lung structure and function. The HGF also prevented destruction of the alveoli by reducing the oxidative stress that contributes to lung injury.

The study showed that the enhancement of hepatocyte growth factor signalling could both protect and repair the airspace from pathologic airspace enlargement or emphysema.

Further research is needed to activate selectively the therapeutic components of HGF signalling and not the cancer-inducing features.


In a new interesting study, published in Current Biology, the researchers cured kittens from blindness (amblyopia).

After those blind animals were left into absole darkness, with no stray light at any time, their vision made a profound and rapid recovery.  Further examination suggested that the restoration of vision depends on the loss of neurofilaments that hold the visual system in place. With those stabilizing elements gone, the visual system becomes free to correct itself.

The researchers are still working out just how much darkness is required, and for how long. Darkness therapy holds promise for the treatment of children with amblyopia, the researchers say.

 I notice recently many unconventional methods, like viral infections to cure cancer, darkness to cure blindness…It gives some hope.