scholarly journals Gene Therapy Approach for Treating DeltaF508, G542X and R553X Cystic Fibrosis Mutations Through the Usage Of CRISPR Prime Editing

Author(s):  
Mira Tafa ◽  
Sevim Naz Karışık ◽  
Ece Begüm Aksoy ◽  
Rüya Aslan

Cystic Fibrosis is a rare genetic disease that affects the transmission of chloride ions due to mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene. Even though there are nearly 2000 mutations identified to be related to the condition, the most common mutation is F508del; deletion of a phenylalanine residue at 508. On the other hand, G542X which is a Class I mutation is also found very commonly and there are no modulator treatments available for it. Furthermore, it was investigated that R553X mutation can as well be corrected simultaneously with G542X mutation. Therefore, the main focus is on designing a gene therapy project that can correct all these three mutations at once by utilizing the prime editing technique via lipid-based delivery. In this way, the mutations can be edited through plasmids that were designed containing 2 pegRNAs and the Cas enzyme. To implement such an approach efficiently, both ex vivo, an animal model, and in vivo steps are to be designed. For the cell line, fibroblasts are selected due to their simplicity and low cost. The animal model of the experiment is determined to be a ferret concerning the high similarity to the human's CFTR protein and finally, the procedure will follow on a direct application in human Cystic Fibrosis patients. The plasmids are thought to be delivered through a cationic liposome that will reach the lungs with the aid of a nebulizer. At the last stage of the experimental procedure, Sanger Sequencing will be done to see if the desired edit within the CFTR has been performed successfully, and Next Generation Sequencing will be executed to see if there has been an off-target mutation in the remainder of the genome. Whereas for detecting the presence and expression of CFTR protein in humans, immunodetection with flow cytometry will be conducted.

2019 ◽  
Vol 40 (06) ◽  
pp. 701-714 ◽  
Author(s):  
Carlo Castellani ◽  
Barry Linnane ◽  
Iwona Pranke ◽  
Federico Cresta ◽  
Isabelle Sermet-Gaudelus ◽  
...  

AbstractThe diagnosis of cystic fibrosis (CF) has traditionally relied on the presence of clinical features of the disease. Today, diagnosis through newborn screening (NBS) is becoming the standard of modern CF care. CF NBS programs can identify CF prior to clinical presentation, but for the advantages of an early diagnosis to accrue a scrupulous system must be in place to ensure all steps in the program are performing. As we move rapidly into the era of CF transmembrane conductance regulator (CFTR) protein modulators, the opportunity to start a presymptomatic infant, identified through CF NBS, on these agents offers the prospect of true disease-modifying interventions which could result in a paradigm shift in CF care.Conversely, the introduction of NBS has resulted in many children being asymptomatic at the time of diagnosis. Some screened newborns are classified as “CF Screening Positive, Inconclusive Diagnosis”, or “CFTR-related metabolic syndrome” when the diagnosis can neither be confirmed nor excluded. Appropriate assessment and follow-up should be arranged at specialist centers as a proportion of these infants and adults will eventually be diagnosed with CF.Symptoms and signs are particularly pertinent when considering a diagnosis of CF outside the context of NBS. In older patients with a late diagnosis, the spectrum of clinical presentation can be very variable with vigilant clinicians from multiple specialties suspecting the diagnosis in conditions such as recurrent pulmonary infections, male infertility, pancreatitis, nasal polyposis, and malabsorption.In addition to clinical symptoms or positive NBS results, sweat test and genetic analysis are cornerstones in the diagnosis of CF, but in some cases the diagnosis cannot be confirmed on genetic or sweat testing. Difficult diagnosis may be supported by in vivo or ex vivo electrophysiology measurements on respiratory or intestinal epithelia. This can be done by either measuring transepithelial nasal potential difference or intestinal current measurements.


2021 ◽  
pp. 1-7
Author(s):  
Sarah Jarrin ◽  
Abrar Hakami ◽  
Ben Newland ◽  
Eilís Dowd

Despite decades of research and billions in global investment, there remains no preventative or curative treatment for any neurodegenerative condition, including Parkinson’s disease (PD). Arguably, the most promising approach for neuroprotection and neurorestoration in PD is using growth factors which can promote the growth and survival of degenerating neurons. However, although neurotrophin therapy may seem like the ideal approach for neurodegenerative disease, the use of growth factors as drugs presents major challenges because of their protein structure which creates serious hurdles related to accessing the brain and specific targeting of affected brain regions. To address these challenges, several different delivery systems have been developed, and two major approaches—direct infusion of the growth factor protein into the target brain region and in vivo gene therapy—have progressed to clinical trials in patients with PD. In addition to these clinically evaluated approaches, a range of other delivery methods are in various degrees of development, each with their own unique potential. This review will give a short overview of some of these alternative delivery systems, with a focus on ex vivo gene therapy and biomaterial-aided protein and gene delivery, and will provide some perspectives on their potential for clinical development and translation.


2021 ◽  
Vol 18 ◽  
pp. 347-354
Author(s):  
Masashi Noda ◽  
Kohei Tatsumi ◽  
Hideto Matsui ◽  
Yasunori Matsunari ◽  
Takeshi Sato ◽  
...  

2021 ◽  
Vol 8 (2) ◽  
pp. 91-96
Author(s):  
Sunil Chaudhry

Cystic Fibrosis (CF) or Mucoviscidosis is an inherited condition. In cystic fibrosis transmembrane conductance regulator (CFTR) protein does not functions properly i.e regulation of fluids and salts outside the cells. Cystic fibrosis affects exocrine glands eg., the mucus-secreting and sweat glands in the respiratory and digestive systems. The frequency of common mutation F508del (deletion of phenylalanine residue at position 508) in children is between 19% and 34%. The estimate frequency of CF as 1:10,000 to 1:40,000 in children. There is no cure for cystic fibrosis, but treatment can reduce symptoms and complications to improve quality of life. Close monitoring and early, aggressive intervention is recommended to slow the progression of CF, which can lead to possible longer life.


2021 ◽  
Vol 21 ◽  
Author(s):  
Vyacheslav Z. Tarantul ◽  
Alexander V. Gavrilenko

: Peripheral artery diseases remain a serious public health problem. Although there are many traditional methods for their treatment using conservative therapeutic techniques and surgery, gene therapy is an alternative and potentially more effective treatment option especially for “no option” patients. This review treats the results of many years of research and application of gene therapy as an example of treatment of patients with critical limb ischemia. Data on successful and unsuccessful attempts to use this technology for treating this disease are presented. Trends in changing the paradigm of approaches to therapeutic angiogenesis are noted: from viral vectors to non-viral vectors, from gene transfer to the whole organism to targeted transfer to cells and tissues, from single gene use to combination of genes; from DNA therapy to RNA therapy, from in vivo therapy to ex vivo therapy.


2020 ◽  
Vol 7 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Amy Sinclair ◽  
Mohamed Sayed Allam ◽  
Evelyn Jean Ferguson ◽  
Mohamed Khairy Mehasseb

Postpartum haemorrhage remains a leading cause of maternal mortality and morbidity. While conventional obstetrics training curricula describe at length the management of postpartum haemorrhage, obstetrics trainees rarely have exposure to surgical management of postpartum haemorrhage in emergency situations due to reduced hours of training. Procedures such as the transverse or longitudinal haemostatic uterine brace sutures are recognised to be safe, simple and allow for the preservation of the uterus. Training during emergency situations is rarely practical or ideal. We describe a simple model that simulates the atonic postnatal uterus and allows trainees to practise the safe placement of the brace sutures. We use a bovine uterus model with attached broad ligament, bladder and ureters for the transverse haemostatic suture. For the longitudinal brace suture, we use a porcine bladder to simulate the uterus, with the ureters and bladder mesentery simulating the tubes and broad ligaments. The placement of the sutures can be practised with the uterus/bladder closed, or open akin to a caesarean section. Tissue dissection and feedback is almost similar to in vivo conditions. The sutures are inserted and driven using the material and correct placement used during real surgery. Our wet lab training model allows the acquisition, maintenance and enhancement of the required technical skills in a controlled environment, using inexpensive, reproducible and widely available specimens. The model has proved successful in both high and low-resource healthcare settings.


2020 ◽  
Vol 21 (12) ◽  
pp. 4486 ◽  
Author(s):  
Giulia Mancini ◽  
Nicoletta Loberto ◽  
Debora Olioso ◽  
Maria Cristina Dechecchi ◽  
Giulio Cabrini ◽  
...  

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein is expressed at the apical plasma membrane (PM) of different epithelial cells. The most common mutation responsible for the onset of cystic fibrosis (CF), F508del, inhibits the biosynthesis and transport of the protein at PM, and also presents gating and stability defects of the membrane anion channel upon its rescue by the use of correctors and potentiators. This prompted a multiple drug strategy for F508delCFTR aimed simultaneously at its rescue, functional potentiation and PM stabilization. Since ganglioside GM1 is involved in the functional stabilization of transmembrane proteins, we investigated its role as an adjuvant to increase the effectiveness of CFTR modulators. According to our results, we found that GM1 resides in the same PM microenvironment as CFTR. In CF cells, the expression of the mutated channel is accompanied by a decrease in the PM GM1 content. Interestingly, by the exogenous administration of GM1, it becomes a component of the PM, reducing the destabilizing effect of the potentiator VX-770 on rescued CFTR protein expression/function and improving its stabilization. This evidence could represent a starting point for developing innovative therapeutic strategies based on the co-administration of GM1, correctors and potentiators, with the aim of improving F508del CFTR function.


Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5095-5103 ◽  
Author(s):  
G Hortelano ◽  
A Al-Hendy ◽  
FA Ofosu ◽  
PL Chang

A potentially cost-effective strategy for gene therapy of hemophilia B is to create universal factor IX-secreting cell lines suitable for implantation into different patients. To avoid graft rejection, the implanted cells are enclosed in alginate-polylysine-alginate microcapsules that are permeable to factor IX diffusion, but impermeable to the hosts' immune mediators. This nonautologous approach was assessed by implanting encapsulated mouse myoblasts secreting human factor IX into allogeneic mice. Human factor IX was detected in the mouse plasma for up to 14 days maximally at approximately 4 ng/mL. Antibodies to human factor IX were detected after 3 weeks at escalating levels, which were sustained throughout the entire experiment (213 days). The antibodies accelerated the clearance of human factor IX from the circulation of the implanted mice and inhibited the detection of human factor IX in the mice plasma in vitro. The encapsulated myoblasts retrieved periodically from the implanted mice up to 213 days postimplantation were viable and continued to secrete human factor IX ex vivo at undiminished rates, hence suggesting continued factor IX gene expression in vivo. Thus, this allogeneic gene therapy strategy represents a potentially feasible alternative to autologous approaches for the treatment of hemophilia B.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4591 ◽  
Author(s):  
Pablo Blázquez-Carmona ◽  
Manuel Sanchez-Raya ◽  
Juan Mora-Macías ◽  
Juan Antonio Gómez-Galán ◽  
Jaime Domínguez ◽  
...  

For the monitoring of bone regeneration processes, the instrumentation of the fixation is an increasingly common technique to indirectly measure the evolution of bone formation instead of ex vivo measurements or traditional in vivo techniques, such as X-ray or visual review. A versatile instrumented external fixator capable of adapting to multiple bone regeneration processes was designed, as well as a wireless acquisition system for the data collection. The design and implementation of the overall architecture of such a system is described in this work, including the hardware, firmware, and mechanical components. The measurements are conditioned and subsequently sent to a PC via wireless communication to be in vivo displayed and analyzed using a developed real-time monitoring application. Moreover, a model for the in vivo estimation of the bone callus stiffness from collected data was defined. This model was validated in vitro using elastic springs, reporting promising results with respect to previous equipment, with average errors and uncertainties below 6.7% and 14.04%. The devices were also validated in vivo performing a bone lengthening treatment on a sheep metatarsus. The resulting system allowed the in vivo mechanical characterization of the bone callus during experimentation, providing a low-cost, simple, and highly reliable solution.


Blood ◽  
1992 ◽  
Vol 79 (6) ◽  
pp. 1602-1611 ◽  
Author(s):  
ME Fabry ◽  
E Fine ◽  
V Rajanayagam ◽  
SM Factor ◽  
J Gore ◽  
...  

Abstract Different morphologic and density classes of sickle cells (SS) may play distinct roles in the generation of vasoocclusion, explaining the complexity of this phenomena. The densest SS red blood cells (RBCs) (SS4) can induce vasoocculsion in ex vivo microcirculatory preparations as well as in an intact animal model. Previous studies of the interaction of SS deformable discocytes with endothelial monolayers or the rat ex vivo mesocecum preparation have shown adhesion that is desmopressin (dDAVP)-stimulated, von Willebrand factor (vWF)-mediated, and limited to the small venules. However, in vivo adhesion of SS RBCs to the endothelium has neither been demonstrated nor characterized; and, in particular, the relation of adhesion to vasoocclusion is unknown. Using an intact animal model that involves injecting saline- washed, density-defined SS RBCs into the femoral artery of a rat, we find that: (1) Quantitative studies of RBCs retained in the rat thigh using 99mTc-labeled RBCs and gamma camera imaging showed that dDAVP induces a threefold increase in retention of normal (AA) cells and deformable SS discocytes (SS2). (2) electron microscopy and Microfil injection show that the retention of SS2 cells is due to adhesion to the vascular endothelium with no evidence of obstruction. (3) H-1 magnetic resonance imaging showed that retention of SS4 cells induced a dose-dependent increase in tissue edema (presumable secondary to tissue hypoxia), while retention of AA or SS2 cells produced no change. We conclude that endothelial adhesion of deformable SS discocytes can be demonstrated in an in vivo animal model, that this adhesion is enhanced by dDAVP (presumably related to, but not necessarily limited to the release of vWF), and that this phenomenon per se does not lead to vasoocclusion. Nevertheless, adhesion of deformable SS discocytes may have consequences. We hypothesize that adhesion of SS discocytes could narrow the lumen of postcapillary venules and facilitate secondary trapping of SS4 cells and lead to subsequent vasoocclusion.


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