Difference between revisions of "Team:Heidelberg/project/cf"
Line 63: | Line 63: | ||
</div> <!-- content --> | </div> <!-- content --> | ||
</div> <!-- container --> | </div> <!-- container --> | ||
+ | |||
+ | <div class="container"> | ||
+ | <div class="content"> | ||
+ | <div class="row"> | ||
+ | <div class="col-lg-12"> | ||
+ | <div class="panel panel‐default"> | ||
+ | <div class="panel‐heading"> | ||
+ | <h3 class="basicheader"> Idea and Methodology </h3> | ||
+ | </div> <!-- panel-heading --> | ||
+ | <div class="panel‐body"> | ||
+ | <div class="row"> | ||
+ | <div class="col-lg-12"> | ||
+ | <h3> Idea </h3> | ||
+ | <p class="basictext"> | ||
+ | Over the last decades, numerous new techniques for the editing of DNA inside living cells have been developed. Tools like Cas9-based homologous recombination enable synthetic biologists to locate targets inside the genome and change complete sections of the DNA with greater than ever ease. Many chronical and hereditary diseases are caused by mutations in the DNA genome that are transcribed into mRNA and translated into altered proteins. As they are not able to fulfill their task correctly, the metabolism of the cell, and in the end the wellbeing of the patient is infringed by these changes. This challenge in mind, the new DNA editing tools gave hope to repair specific regions in the genome that are responsible for the malicious phenotypes. Despite vast improvements in the ability to target virtually any gene, the DNA editing gene therapy still has to overcome many challenges and and mediate certain risks. The strategy of changing the cells’ DNA requires the system to be highly reliable. A genetic instability caused by the unwanted insertion of the therapeutic gene can create permanent damage and may lead to an increased cancer risk or even turn out fatal. | ||
+ | A promising way to circumvent this risks, however displaying the full potential of curing a disease by repair of the damaged sequences, is given by the idea of RNA gene therapy. In this strategy the required correction is done on mRNA level. As this type of therapy can be applied transiently, the side effects can be considered to be lower. (QUELLE) The straightforward strategy to change mRNAs relies on the use of mRNA editing ribozymes like trans-splicing ribozymes or highly engineered RNA cleaving and ligating systems (QUELLE). | ||
+ | </p> | ||
+ | </div> <!-- col-lg-12 --> | ||
+ | </div> <!-- row --> | ||
+ | </div> <!-- panel-body --> | ||
+ | </div> <!-- panel panel‐default --> | ||
+ | </div> <!-- col-lg-12 --> | ||
+ | </div> <!-- row --> | ||
+ | </div> <!-- content --> | ||
+ | </div> <!-- container --> | ||
+ | |||
</body> | </body> | ||
</html> | </html> |
Revision as of 10:17, 18 September 2015
Introduction
Cystic Fibrosis and Causes of the Disease
Cystic fibrosis (CF) is a recessive monogenetic disorder, which is present in every ethnicity worldwide. Especially Europeans are affected with 1:2000 to 1:3000 people exhibiting cystic fibrosis
The disease can be a result of multiple different genetic mutations. At the moment 2001 mutations, which result in CF, are known. The most abundant mutation is the ΔF508, also called Phe508del or F508del mutation (http://www.genet.sickkids.on.ca/StatisticsPage.html, Statistics Page of the CFTR mutation database [accessed 29.08.2015]), which occurs in about 70% of western, central, northern and north-eastern Europe. In Germany, the prevalence of the mutation lies between 63.5% and 74.2% depending on the region. On the Faroe Islands 100% of cystic fibrosis patients exhibit the ΔF508 mutation
The mutations leading to CF occur in one particular gene: The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. The CFTR-gene encodes for a transmembrane anion channel, expressed in epithelial cells. The CFTR-protein is part of the ATP-binding cassette protein superfamily. Anions, especially chloride ions, are able to pass the membrane passively along the concentration gradient. ATP helps to stabilize the open channel to establish a higher anion flux through the channel. The CFTR consists of 5 domains: Two nucleotide binding domains (NBD1 and NBD2), two transmembrane domains (TMD1 and TMD2) and one regulatory domain (RD). The CFTR-channel is moreover regulated by protein kinase A (PKA) and ATP
Out of the 2001 mutation leading to CF the most common ΔF508-mutation leads to a misfolding of the CFTR-protein. This leads to a faster degradation, a reduction in function and consequently a damping in cell membrane integration rate
Symptoms of Cystic Fibrosis
In the 1950s, most patients died in infancy or childhood
Approaches in Mediaction and Therapy
The classical approach to medicate cystic fibrosis is a mixture of nebulization therapy, physiotherapy, physical exercise, dietaries and antibiotic therapy
The used drugs to fight cystic fibrosis belong mostly to the following classes: Bronchodilatorica, mucolytics, antibiotics and enzymes. Prominent examples of CF medications are dornase alfa
Other approaches to treat cystic fibrosis want to cure cystic fibrosis, by targeting its cause, with gene therapy. Gene therapy approaches to medicate CF can be divided in two categories: Non-viral gene therapy
Transsplicing Ribozymes and Twinzymes
Amongst all small self-cleaving ribozymes, the hairpin ribozyme is very well characterized
Using Twinzymes as Therapeutical Approach
Twin ribozymes are a new application for the treatment of cystic fibrosis. Through mRNA-editing, we could establish a ribozymal gene therapy and revolutionize the treatment of CF. Compared to the viral and non-viral therapy our ribozymal gene-therapy/mRNA-editing has several benefits. Like the non-viral therapy most problems with the immune systems can be evaded by application through liposomes or nanoparticles, like it was done for siRNA
Idea and Methodology
Idea
Over the last decades, numerous new techniques for the editing of DNA inside living cells have been developed. Tools like Cas9-based homologous recombination enable synthetic biologists to locate targets inside the genome and change complete sections of the DNA with greater than ever ease. Many chronical and hereditary diseases are caused by mutations in the DNA genome that are transcribed into mRNA and translated into altered proteins. As they are not able to fulfill their task correctly, the metabolism of the cell, and in the end the wellbeing of the patient is infringed by these changes. This challenge in mind, the new DNA editing tools gave hope to repair specific regions in the genome that are responsible for the malicious phenotypes. Despite vast improvements in the ability to target virtually any gene, the DNA editing gene therapy still has to overcome many challenges and and mediate certain risks. The strategy of changing the cells’ DNA requires the system to be highly reliable. A genetic instability caused by the unwanted insertion of the therapeutic gene can create permanent damage and may lead to an increased cancer risk or even turn out fatal. A promising way to circumvent this risks, however displaying the full potential of curing a disease by repair of the damaged sequences, is given by the idea of RNA gene therapy. In this strategy the required correction is done on mRNA level. As this type of therapy can be applied transiently, the side effects can be considered to be lower. (QUELLE) The straightforward strategy to change mRNAs relies on the use of mRNA editing ribozymes like trans-splicing ribozymes or highly engineered RNA cleaving and ligating systems (QUELLE).