Systemic Delivery of Antisense Oligomer in Animal Models and Its Implications for Treating DMD

Mus musculus is the most commonly used animal model in microRNA research; however, little is known about the endogenous miRNome of the animals used in the miRNA-targeting preclinical studies with the human xenografts. In the presented study, we evaluated the NOD/SCID gamma mouse model for the preclinical study of systemic miR-215-5p substitution with a semitelechelic poly[N-(2-hydroxypropyl)-methacrylamide]-based carrier conjugated with miR-215-5p-mimic via a reductively degradable disulfide bond. Murine mmu-miR-215-5p and human hsa-miR-215-5p have a high homology of mature sequences with only one nucleotide substitution. Due to the high homology of hsa-miR-215-5p and mmu-hsa-miR-215-5p, a similar expression in human and NOD/SCID gamma mice was expected. Expression of mmu-miR-215 in murine organs did not indicate tissue-specific expression and was highly expressed in all examined tissues. All animals included in the study showed a significantly higher concentration of miR-215-5p in the blood plasma compared to human blood plasma, where miR-215-5p is on the verge of a reliable detection limit. However, circulating mmu-miR-215-5p did not enter the human xenograft tumors generated with colorectal cancer cell lines since the levels of miR-215-5p in control tumors remained notably lower compared to those originally transfected with miR-215-5p. Finally, the systemic administration of polymer-miR-215-5p-mimic conjugate to the tail vein did not increase miR-215-5p in NOD/SCID gamma mouse blood plasma, organs, and subcutaneous tumors. It was impossible to distinguish hsa-miR-215-5p and mmu-miR-215-5p in the murine blood and organs due to the high expression of endogenous mmu-miR-215-5p. In conclusion, the examination of endogenous tissue and circulating miRNome of an experimental animal model of choice might be necessary for future miRNA studies focused on the systemic delivery of miRNA-based drugs conducted in the animal models.

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Application of Alphaviral Vectors for Immunomodulation in Cancer Therapy

Current Pharmaceutical Design ◽

10.2174/1381612823666170622094715 ◽

2017 ◽

Vol 23 (32) ◽

pp. 4906-4932 ◽

Cited By ~ 4

Author(s):

Anna Zajakina ◽

Karina Spunde ◽

Kenneth Lundstrom

Keyword(s):

Animal Models ◽

Protein Delivery ◽

Sindbis Virus ◽

Semliki Forest Virus ◽

Tumor Regression ◽

Survival Rates ◽

Expression Vectors ◽

Cancer Therapies ◽

Systemic Delivery ◽

Equine Encephalitis Virus

Background: The lack of specific and efficient cancer therapies has influenced the development of novel approaches, such as immunotherapy, which from its original application of immunogenic protein delivery has developed into the use of more sophisticated recombinant gene delivery methods to achieve better safety and efficacy profiles. This approach involves viral and non-viral delivery systems. Methods: Expression vectors have been engineered for alphaviruses, including Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus. For immunotherapeutic applications, recombinant particles, RNA replicons and layered DNA vectors that express tumor-associated antigens (TAAs) and cytokines have been studied in animal models and in a few clinical trials. Results: Immunization studies with TAAs and cytokines have elicited strong antibody responses and vaccination has provided protection against challenges with tumor cells in mouse models. Furthermore, the combination of TAAs and cytokines, antibodies and growth factors and the co-administration of chemotherapeutics and bacteriabased adjuvants have enhanced immunogenicity. Intratumoral and systemic delivery of recombinant alphavirus particles has demonstrated significant tumor regression and prolonged survival rates in rodent tumor models. Conclusion: Alphavirus-based immunotherapy represents a rapid and efficient method for prophylactic and therapeutic applications in animal models.

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Abstract 583: RNAi Therapeutics For The Lowering Of Cholesterol

Circulation ◽

10.1161/circ.116.suppl_16.ii_105-d ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Kevin Fitzgerald ◽

Maria Frank-Kamenetsky ◽

Tracy S Zimmermann ◽

Jay Horton ◽

Akin Akinc ◽

...

Keyword(s):

Animal Models ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Small Interfering Rnas ◽

Systemic Delivery ◽

Apob Mrna ◽

New Class ◽

Safety Studies ◽

Rnai Therapeutics

Delivery of small interfering RNAs (siRNAs) in vivo , using clinically relevant modes of administration, is critical for the advancement of RNA interference (RNAi) therapeutics. In this work, we demonstrate systemic delivery of siRNAs and potent in vivo down-modulation of two important disease targets, apolipoprotein B (apoB) and proprotein convertase subtilisin kexin 9 (PCSK9). A single injection of liposomal siRNA resulted in >90% silencing of apoB mRNA expression in the liver 48 h after administration. The effect was demonstrated to occur through cleavage of the apoB mRNA at precisely the site predicted for the RNAi mechanism. Reductions in apoB protein, cholesterol, and low-density lipoprotein (LDLc) levels were observed in 48 hours that lasted for at least 23 days, thus demonstrating an immediate, potent and durable biological effect. In addition to apoB we have also demonstrated the ability to down-modulate other important liver targets such as PCSK9. PCSK9 has been closely implicated in LDLc regulation. We have demonstrated PCSK9 down-modulation in several animal models including, mouse, humanized mouse, rat, and non-human primate. Down-modulation of PCSK9 levels resulted in significant lowering of cholesterol (20 – 60%) in all animal models tested. These findings strongly support the potential of RNAi therapeutics as a new class of drug for metabolic and cardiovascular diseases. Our next steps include selecting the most potent lead molecule and moving it into GLP safety studies.

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Reductionist thinking and animal models in neuropsychiatric research

Behavioral and Brain Sciences ◽

10.1017/s0140525x18001231 ◽

2019 ◽

Vol 42 ◽

Cited By ~ 1

Author(s):

Nicole M. Baran

Keyword(s):

Animal Models ◽

Mental Disorders ◽

Environmental Factors ◽

Neuropsychiatric Disorders ◽

Model Organisms ◽

Developmental Genetic ◽

Term Study ◽

Genetic And Environmental Factors ◽

Mechanisms Of Plasticity

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.

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Inflammational Animal Models for Schizophrenia

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000216 ◽

2015 ◽

Vol 223 (3) ◽

pp. 157-164 ◽

Cited By ~ 1

Author(s):

Georg Juckel

Keyword(s):

Animal Model ◽

Animal Models ◽

Immune Activation ◽

Microglial Activation ◽

Treatment Options ◽

Early Adulthood ◽

Brain Regions ◽

Synaptic Connections ◽

Preventive Interventions ◽

Immunological System

Abstract. Inflammational-immunological processes within the pathophysiology of schizophrenia seem to play an important role. Early signals of neurobiological changes in the embryonal phase of brain in later patients with schizophrenia might lead to activation of the immunological system, for example, of cytokines and microglial cells. Microglia then induces – via the neurotoxic activities of these cells as an overreaction – a rarification of synaptic connections in frontal and temporal brain regions, that is, reduction of the neuropil. Promising inflammational animal models for schizophrenia with high validity can be used today to mimic behavioral as well as neurobiological findings in patients, for example, the well-known neurochemical alterations of dopaminergic, glutamatergic, serotonergic, and other neurotransmitter systems. Also the microglial activation can be modeled well within one of this models, that is, the inflammational PolyI:C animal model of schizophrenia, showing a time peak in late adolescence/early adulthood. The exact mechanism, by which activated microglia cells then triggers further neurodegeneration, must now be investigated in broader detail. Thus, these animal models can be used to understand the pathophysiology of schizophrenia better especially concerning the interaction of immune activation, inflammation, and neurodegeneration. This could also lead to the development of anti-inflammational treatment options and of preventive interventions.

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