Leptin instead of insulin?

Life without insulin is possible

NanoNewsNet based on UNIGE materials: La vie sans insuline est possibleThe approach to the treatment of diabetes mellitus, based on the constant administration of insulin, is associated with serious side effects.

Scientists at the University of Geneva (Universite de Geneve, UNIGE) have deciphered the basic physiological mechanisms that make life possible without insulin. The results of their study, published in the journal Cell Metabolism (Fujikawa et al., Leptin Engages a Hypothalamic Neurocircuitry to Permit Survival in the Absence of Insulin), pave the way for new treatments for diabetes.

Several million people around the world suffer from the fact that the beta cells of their pancreas do not produce enough insulin - a hormone that plays a key role in regulating energy metabolism, including in the metabolism of substances such as glucose. Without treatment, insulin deficiency, caused mainly by diabetes (type 1 and type 2), is fraught with the saddest outcome: today, only daily injections of insulin save the lives of diabetic patients.

While life without insulin seems absolutely unthinkable, a group of scientists led by UNIGE Professor of Cell Physiology and Metabolism Roberto Coppari has just proved the opposite: life without insulin is quite possible. Having refuted the long-standing dogma, scientists are currently considering alternatives to insulin treatment, which is fraught with serious risk for many patients. An error in dosage can cause hypoglycemia, that is, a decrease in blood glucose levels, which can cause, at least, loss of consciousness. Moreover, about 90% of patients over the age of 55 who have received insulin injections for several years suffer from cardiovascular diseases caused by elevated cholesterol levels due to the lipogenic properties of the hormone.

Swiss researchers conducted a series of experiments on rodents deprived of the ability to synthesize insulin, which were injected with leptin, a hormone that regulates energy metabolism and appetite. Thanks to leptin, all animals perfectly tolerated the state of insulin deficiency.

Leptin has two significant advantages over insulin: it does not cause hypoglycemia and has a lipolytic effect.

"Thanks to this discovery, an alternative to insulin treatment appears. Now we need to understand the mechanisms by which leptin affects glucose levels regardless of insulin levels," Professor Koppari comments on his study.

However, scientists have already managed to check whether the neurons involved in the implementation of the antidiabetic action of leptin in healthy mammals play a similar role in rodents with insulin deficiency. To their surprise, in conditions of insulin deficiency, the main mediators of the effect of leptin on glucose levels were GABA-ergic neurons of the hypothalamus. The effect of these neurons on glucose levels has never been considered significant before.

In addition, peripheral target tissues of leptin were identified in conditions of insulin deficiency. These include, first of all, the liver, flounder muscle and brown adipose tissue, which can become direct targets of future therapeutic drugs.

Thanks to this discovery, it became known where the path to insulin-free treatment of diabetes mellitus lies. Understanding the functions of leptin and its effects on the body will eventually allow us to identify the molecules that will form the basis of a new method of therapy.

Portal "Eternal youth" http://vechnayamolodost.ru10.09.2013