Hemophilia gene therapy was tested on dogs

Hemophilia will be cured by the genome
Scientists managed to cope with hemophilia with the help of a gene and a virusNadezhda Markina, <url>

Experts described the first successful case of hemophilia cure in dogs.

The next step is a person. Nevertheless, scientists could not cure Tsarevich Alexei yet. So far, dogs are cured only of hemophilia A, whereas the son of Nicholas II had hemophilia B.

Scientists managed to cure hemophilia by gene therapy. Specialists from the Medical College of Wisconsin tested their method on dogs, as reported in the journal Nature Communications: Du et al., Platelet-targeted gene therapy with human factor VIII establishes haemostasis in dogs with haemophilia A. (A popular retelling of the work can be read on the Medical Xpress website: Gene tests on dogs boost hopes for haemophilia – As a result of treatment, the dogs got rid of episodes of pathological bleeding and have remained healthy for two and a half years. This is the first time that hemophilia has been cured in large laboratory animals by delivering a gene to blood cells. The authors of the study expect that their method will be the first step towards the clinical practice of treating hemophilia in patients.

Hemophilia is a severe genetic disease that manifests itself in pathological bleeding due to blood clotting disorders. Patients with hemophilia A lack the protein factor VIII (F8) of the blood coagulation system (antihemophilic globulin), which is normally contained in tromobocytes – "blood plates".

With hemophilia, the risk of death of the patient from hemorrhage in the brain and other vital organs increases sharply, even with a minor injury. The disease affects one in 10 thousand men, and in women it is extremely rare. This feature is explained by the fact that the F8 protein gene, which does not synthesize protein due to mutation, is located on the X chromosome. In women, the mutant copy of the gene is compensated by a healthy gene on the paired X chromosome. Since men have only one X chromosome, the mutation leads to the disease.

The most famous case of hemophilia is the disease of Tsarevich Alexei, the only son of Nicholas II, who inherited it from his mother, Empress Alexandra Feodorovna, and she, in turn, received a mutant gene from her grandmother, Queen Victoria of England. At the same time, all women of royal blood were carriers of the mutant gene, and their sons who received a single X chromosome from their mother became ill.

But, as shown by the research of an international group of scientists led by Evgeny Rogaev, about which the newspaper wrote.Ru", in Tsarevich Alexei, hemophilia was caused by a mutation of another gene – factor IX (F9). This is another type of disease – hemophilia B, more rare.

David Wilcox and his colleagues used lentivirus as a vector to deliver the F8 gene to stem hematopoietic (hematopoietic) cells of dogs with hemophilia A. The disease in these laboratory dogs was caused by the fact that the F8 gene was knocked out (blocked) in them. The bone marrow transplantation procedure with the F8 gene-carrying viral genetic construct was carried out on three dogs. This led to the fact that factor VIII began to be synthesized in the blood of dogs and accumulate in platelets, which play a key role in the process of blood clotting.

After treatment, two dogs whose F8 protein reached a particularly high level completely got rid of pathological bleeding. Since episodes of bleeding have not been observed for two and a half years, scientists regard this as a stable result.

This is not the first attempt to cope with hemophilia with the help of gene therapy. In previous studies, scientists have tried to inject the F8 gene using an adenovirus vector into the hepatic vein. But we came to the conclusion that this method can cause complications. Current work has shown that hematopoietic stem cells seem to be an ideal target for F8 gene transfer. But, of course, in order to use the method on patients, additional research will be required.

Portal "Eternal youth" http://vechnayamolodost.ru20.11.2013