Diabetes

 

 

Diabetes is characterized by insulin deficiency and an excess of a hormone antagonist, glucagon. Scientists have shown that it is possible to reprogram cells secreting glucagon to convert them into insulin-secreting cells. Or the art of kill two birds with one stone.


All about diabetes:

 

When the body is no longer able to manage his blood sugar in the blood is diabetes. Often this condition is summarized by a lack of insulin, the pancreatic hormone responsible for lowering blood sugar. We forget to say that parallel the production of glucagon antagonist, is too high. Ideally, to establish an effective treatment against the disease is to raise insulin levels while reducing the synthesis of glucagon.


These two hormones are secreted in the same place in the islets of the pancreas (called Langerhans). Insulin is produced by beta cells, glucagon by alpha cells. Scientists from the Faculty of Medicine of the University of Pennsylvania (Philadelphia, USA) have almost achieved the feat of reprogramming alpha cells to make beta cells. Even if the transformation is incomplete, it is sufficient to induce the production of insulin.

 

Alpha cells not fully differentiated:

 

It is possible to change the destiny of a differentiated cell. By adding a few transcription factors, is forced to return to the state of stem cell, before pushing to specialize in a particular type. However, for now, attempts to generate beta cells so proved unsuccessful for clinical application.

The authors nevertheless observed that pancreatic alpha cells were still plastic, as if they were not completely differentiated. Thus, they see a way to modify it to make it evolve in beta cell. These pancreatic alpha cells, found in structures called islets of Langerhans, have been modified. Proof: if most of them secrete glucagon (red), others show the transcription factor Pdx1 (white), normally specific to pancreatic beta cells. Reprogramming is possible. To do this, they had to play with histones, the proteins around which DNA winds the thread. These are particularly involved in the regulation, positive or negative, of the genes. In the alpha cells, as yet undifferentiated tissues, there are two histone modifications equipped antagonists: one of them promotes the expression of genes when the other inhibits transcription.

 

Modified alpha cells produce insulin:

 

As explained in the Journal of Clinical Investigation, the authors collected samples of pancreas of patients died. They put these cells in culture and were treated with a compound called adenosine dialdehyde (Adox also called). This molecule is an inhibitor of methyltransferase, that is to say, an enzyme which, as its name suggests, transfers methyl groups on histones. Thus, by modifying the protein structure of DNA compaction, they alter gene expression.

 

Finally, the alpha cells began to turn and had some markers characteristic of beta cells. Their reprogramming is incomplete but they began to secrete insulin. The theory shows that it works.


Types of Diabetes: Type 1 Diabetes, Type 2 Diabetes and Gestational Diabetes.

Need a cure for diabetes:

 

Scientists hope this discovery will help to make pancreatic beta cells for large-scale transplant patients with diabetes, whether type 1 or type 2. Even if the technology is not yet developed, they could have taken an interesting step.

 

The next step would be to achieve the same performance, but in vivo. In which case you would not need to transplant, but could control the populations of pancreatic cells directly into the patient. A delicate adjustment which requires many years of previous experience. Not tomorrow then.

 

Meanwhile, diabetes is a deadly disease whose treatments fail to reduce symptoms, but are unable to provide the body with the key to finally regulate blood sugar levels. However, year after year, the number of patients is increasing sharply in France. For example, in 2009, there were approximately 3.5 million diabetics in France. A figure thought to be achieved by 2016 ... only curative therapy is becoming increasingly necessary.