Terapia genética de injeção intravítrea de rAAV2-ND4 para neuropatia óptica hereditária de Leber: uma revisão sistemática / rAAV2-ND4 intravitreal injection gene therapy for Leber's hereditary optic neuropathy: a systematic review

RESUMO A neuropatia óptica hereditária de Leber é uma doença mitocondrial hereditária neurodegenerativa. A taxa potencial de recuperação espontânea é controversa na literatura. A terapia genética tem sido estudada como suporte aos pacientes. O objetivo desta revisão foi avaliar qualitativamente a segurança, os efeitos adversos e a eficácia da terapia gênica disponível. Trata-se de uma revisão sistemática de artigos indexados nas bases de dados PubMed®, Biblioteca Virtual em Saúde, SciELO, Cochrane, ScienceDirect, Scopus e Lilacs no primeiro semestre de 2021. Os critérios de inclusão e filtros foram: artigos relacionados ao tema, estudos randomizados, ensaios clínicos, trabalhos em humanos, últimos 5 anos, nas línguas portuguesa, inglesa e espanhola e texto completo disponível gratuitamente. Os parâmetros de exclusão foram: artigos duplicados, fuga ao tema, artigos de revisão, trabalhos não disponíveis e que fugiam aos critérios de inclusão. O coeficiente de kappa foi 0,812. A terapia não apresentou efeitos adversos sérios em nenhum dos artigos selecionados, e os efeitos menores sofreram 100% de remissão espontânea após o tratamento. Apesar de NAbs terem sido encontrados no soro de alguns pacientes, não houve associação entre a resposta imune adaptativa e a injeção do vetor viral. O tratamento foi eficaz na melhora da acuidade e campo visual. Vários estudos confirmaram a eficácia da terapia gênica, em doses baixas e médias, na melhora da acuidade visual e também sobre os efeitos adversos comuns relacionados à altas doses. A resposta imune humoral e a variação dos NAbs no soro foi citada em mais de um artigo. A terapia foi eficaz na melhora da acuidade visual e os efeitos adversos que surgiram foram tratados facilmente. No entanto, a resposta imune humoral ainda precisa ser estudada.

ABSTRACT Leber's Hereditary Optic Neuropathy (LHON) is an inherited neurodegenerative mitochondrial disease. The potential rate of spontaneous recovery is controversial in the literature. Gene therapy has been studied to support patients. The objective of this review was to qualitatively assess the safety, adverse effects, and efficacy of available gene therapy. This is a systematic review of articles indexed in PubMed®, VHL, SciELO, Cochrane, ScienceDirect, Scopus, and Lilacs databases, in the first half of 2021. Inclusion criteria and filters were: articles related to the topic, randomized studies, clinical trials, work in humans, last 5 years, in Portuguese, English, and Spanish and full text available for free. The exclusion parameters were: duplicate articles, not related to the topic, review articles, not available works, and works that did not meet the inclusion criteria. The kappa coefficient was 0.812. The therapy had no serious adverse effects in any of the selected articles, and minor effects experienced 100% spontaneous remission after treatment. Although NAbs were found in the serum of some patients, there was no association between the adaptive immune response and the injection of the viral vector. The treatment was effective in improving acuity and visual field. Several studies have confirmed the effectiveness of gene therapy, at low and medium doses, in improving visual acuity and also on common adverse effects related to high doses. The humoral immune response and the variation in serum NAbs was cited in more than one article. The therapy was effective in improving visual acuity and the adverse effects that arose were easily treated. However, the humoral immune response still needs to be studied.

Nanobubbles: A Novel Targeted Drug Delivery System

Abstract Nanobubbles are nanometer size bubbles having different constituents of varying physicochemical characteristic for the inner core and outer shell. Nanobubbles are mainly fabricated to improve the stability, bioavailability and improve the biodistribution of the delivered drug to the specific targeted site. Their small sizes bubbles allow the possibility of extravasation from blood vessels into the surrounding tissues and ultrasound-targeted site-specific release with minimal invasiveness. Nanobubbles are developing as important contrast agents for imaging and carriers for drug delivery at targeted region. Sonication is the primary method for preparation of nanobubbles followed by thin-layer evaporation, high shear emulsification, mechanical agitation and coacervation or coalescence. With exposure to ultrasound/extracorporeal shock waves, the drug is liberated from the nanobubbles into the target cells. This review paper is an effort to reveal the different formulation development techniques briefly and varying shell and core content for developing nanobubbles.

Combating oncogene activation associated with retrovirus-mediated gene therapy of X-linked severe combined immunodeficiency

A successful gene therapy clinical trial that also encountered serious adverse effects has sparked extensive study and debate about the future directions for retrovirus-mediated interventions. Treatment of X-linked severe combined immunodeficiency with an oncoretrovirus harboring a normal copy of the gc gene was applied in two clinical trials, essentially curing 13 of 16 infants, restoring a normal immune system without the need for additional immune-related therapies. Approximately 3 years after their gene therapy, tragically, 3 of these children, all from the same trial, developed leukemia as a result of this experimental treatment. The current understanding of the mechanism behind this leukemogenesis involves three critical and cooperating factors, i.e., viral integration, oncogene activation, and the function of the therapeutic gene. In this review, we will explore the causes of this unwanted event and some of the possibilities for reducing the risk of its reoccurrence.

Doping droops.

Drug abuse is a major concern in the athletic world. The misconception among athletes and their coaches is that when an athlete breaks a record it is due to some "magic ingredient" and not because of training, hard work, mental attitude and championship performance. The personal motivation to win in competitive sports has been intensified by national, political, professional and economic incentives. Under this increased pressure athletes have turned to finding this "magic ingredient". Athlete turns to mechanical (exercise, massage), nutritional (vitamins, minerals), pharmacological (medicines) or gene therapies to have an edge over other players. The World Anti-Doping Agency (WADA) has already asked scientists to help find ways to prevent gene therapy from becoming the newest form of doping. The safety of the life of athletes is compromised with all forms of doping techniques, be it a side effect of a drug or a new technique of gene doping.

Laronidase for treating mucopolysaccharidosis type I

Mucopolysaccharidoses are a group of inherited metabolic diseases caused by the absence or deficiency of the lysosomal enzymes that are needed for breaking down glycosaminoglycans (GAGs). Over time, GAGs collect in cells, blood and connective tissues, and increased amounts are excreted in the urine. The result is permanent and includes progressive cell damage that affects the individual’s appearance, physical abilities, organ and system functioning and, in certain cases, mental development. Enzyme replacement therapies are currently in use or are being tested for at least three different subtypes (I, II and VI). The aim of the present study was to evaluate the effectiveness and safety of laronidase for treating mucopolysaccharidosis type I. A systematic review of the literature was conducted. A computerized electronic search was then conducted using the CENTRAL, Pubmed, EMBASE, and LILACS databases, to identify any randomized controlled trials. The last date of the search was June 2006. There was no possibility of combining the results, because only one study was included. In the pivotal placebo-controlled trial conducted over a 26-week period, there was a reduction in the urinary excretion of GAGs among treated patients. Regarding adverse events, there were no laronidase-related serious adverse events or deaths. Laronidase seems to be a promising agent for treating mucopolysaccharidosis type I, as shown by the reduction in the urinary excretion of GAGs and the associated improvements in vital capacity and in the performance of defined physical tasks.

Catheter-based adenovirus-mediated local intravascular gene delivery of a soluble TGF-beta type II receptor using an Infiltrator in porcine coronary arteries: efficacy and complications

Enhanced extracellular matrix (ECM) accumulation is an important finding in human restenotic arterial neointima after angioplasty. Transforming growth factor b1(TGF-beta1) is known to regulate the synthesis and turnover of a variety of ECM components, and may play an important role in restenosis. Recombinant adenoviral vector expressing an ectodomain of the TGF-beta type II receptor fused to the human immunoglobulin Fc portion (AdT beta-ExR) inhibits the action of TGF-beta probably either by adsorbing TGF-beta or by acting as a dominant negative receptor. We carried out a catheter-based local adenovirus mediated gene delivery using an Infiltrator in porcine coronary arteries to know the pattern of gene expression, efficacy and procedural complications. Twenty four coronary arteries in 13 pigs were used for intravascular gene delivery by intramural injection with either AdT beta-ExR or adenovirus expressing b-galactosidase (AdCALacZ). Direct immunofluorescent staining and reverse transcription polymerase chain reaction (RTPCR) were used for detection of type II TGF-beta receptor and its mRNA respectively. X-Gal histochemistry was performed to identify b-galactosidase. Both soluble TGF-beta receptor and b-galactosidase were expressed locally in the media and adventita at injected arterial segments without any significant dissemination to remote area. Intravascular gene transfection performed with various titer of each adenoviral vector showed that AdT beta-ExR of 5x10(8) pfu and AdCALacZ of 2.5 x 10(8) pfu were the minimum titer for the expression of each transgene. Infiltration of CD3 positive T cells was detected by immunohistochemical staining in the area of each transgene expression, and tends to decrease over time after gene delivery. Pathological study of 24 treated arteries showed complications such as disruption of external elastic lamina with hemorrhage (n = 4), minimal disruption of internal elastic lamina and endothelial layer, and medial thickening. In conclusion, catheter-based local intravascular gene delivery of adenoviral vector is feasible and effective in a selected artery, but must be undertaken with caution due to possible lethal complications. Local delivery of soluble TGF-beta type II receptor in this way may provide an effective intravascular gene therapy to inhibit TGF-beta signal pathway without any significant systemic side effect.

Catheter-based adenovirus-mediated local intravascular gene delivery of a soluble TGF-beta type II receptor using an Infiltrator in porcine coronary arteries: efficacy and complications

Enhanced extracellular matrix (ECM) accumulation is an important finding in human restenotic arterial neointima after angioplasty. Transforming growth factor b1(TGF-beta1) is known to regulate the synthesis and turnover of a variety of ECM components, and may play an important role in restenosis. Recombinant adenoviral vector expressing an ectodomain of the TGF-beta type II receptor fused to the human immunoglobulin Fc portion (AdT beta-ExR) inhibits the action of TGF-beta probably either by adsorbing TGF-beta or by acting as a dominant negative receptor. We carried out a catheter-based local adenovirus mediated gene delivery using an Infiltrator in porcine coronary arteries to know the pattern of gene expression, efficacy and procedural complications. Twenty four coronary arteries in 13 pigs were used for intravascular gene delivery by intramural injection with either AdT beta-ExR or adenovirus expressing b-galactosidase (AdCALacZ). Direct immunofluorescent staining and reverse transcription polymerase chain reaction (RTPCR) were used for detection of type II TGF-beta receptor and its mRNA respectively. X-Gal histochemistry was performed to identify b-galactosidase. Both soluble TGF-beta receptor and b-galactosidase were expressed locally in the media and adventita at injected arterial segments without any significant dissemination to remote area. Intravascular gene transfection performed with various titer of each adenoviral vector showed that AdT beta-ExR of 5x10(8) pfu and AdCALacZ of 2.5 x 10(8) pfu were the minimum titer for the expression of each transgene. Infiltration of CD3 positive T cells was detected by immunohistochemical staining in the area of each transgene expression, and tends to decrease over time after gene delivery. Pathological study of 24 treated arteries showed complications such as disruption of external elastic lamina with hemorrhage (n = 4), minimal disruption of internal elastic lamina and endothelial layer, and medial thickening. In conclusion, catheter-based local intravascular gene delivery of adenoviral vector is feasible and effective in a selected artery, but must be undertaken with caution due to possible lethal complications. Local delivery of soluble TGF-beta type II receptor in this way may provide an effective intravascular gene therapy to inhibit TGF-beta signal pathway without any significant systemic side effect.

Terapia génica / Gene therapy

La aplicación de la genética molecular a la biología de la enfermedad humana tiene un profundo efecto en la comprensión de los mecanismos moleculares de la patogénesis de la enfermedad. En esta revisión se proporciona una introducción y bosquejo de la terapia génetica, y se presentan y discuten las técnicas más actualizadas para hacer la entrega de genes asi como las hazañas clínicas y experimentales realizadas hasta la fecha. El desarrollo de métodos de entrega de genes a células de mamífero lleva a la posibilidad de tratar la enfermedad humana a través de terapias basadas en genes. Como resultado, conceptos y métodos que podían considerarse ciencia ficción hace 50 años se aplican ahora en el tratamiento de diversas enfermedades. La aplicación de la terapia génica está rompiendo las fronteras tradicionales en la cual la medicina moderna ha estado sumergida. Sin embargo, no obstante los progresos, un gran número de dificultades técnicas necesitan ser resueltas antes de que la terapia génica pueda ser segura y eficientemente aplicada en la clínica. Los desarrollos tecnológicos, particularmente la entrega de genes y el trasplante celular, son críticos para la práctica exitosa de la terapia génica