Longevity Gene Therapy Is the Best Way to Defeat Aging
Maria Konovalenko
2014-09-23 00:00:00
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We propose developing a gene therapy that will radically extend lifespan. Genes that promote longevity of model animals will be used as therapeutic agents. We will manipulate not a single gene, but several aging mechanisms simultaneously. A combination of different approaches may lead to an additive or even a synergistic effect, resulting in a very long life expectancy. For this purpose, an animal will be affected by a set of genes that contribute to longevity. In addition, a gene therapy of all major age-related pathologies will be developed to improve the functioning of individual organs and tissues in old age. As a result, we will develop a comprehensive treatment that will not only dramatically extend lifespan, but will also prevent the decrepitude of the body. Experiments will be conducted in old mice. Thus, in case of success, the developed method of aging treatment can be quickly moved to clinical trials.

The goal of the project is to develop a complex gene therapy that will drastically increase mouse lifespan and prevent tissue pathology in old age, coupled with the safety assessment of the treatment.

Project description

11 genes that are most promising in terms of life extension (table 1) will be used as targets for gene therapy. We will affect both the biological aging mechanisms, common to all the cells of the organism, as well as the primary neuroendocrine center, that regulates the whole organism’s longevity – the hypothalamus. The expression increase or decrease of these genes in animal models was shown to result in boosted longevity. If the increase in expression of a particular gene is necessary for longevity, we will deliver this gene into the body. If, on the other hand, longevity depends on the inhibition of a certain gene’s expression, we will introduce a genetic construct that encodes small RNAs that inhibit the expression of the target gene. Two out of 10 genes have previously been used for gene therapy of aging: the lifespan of mice was increased by 20% (Zhang et al., 2013, Bernardes de Jesus et al., 2012). In addition, we will deliver 8 genes that prevent the individual tissue function disruption in old age. Each of these genes separately has previously been successfully used for gene therapy of one of the age-related diseases in rodent models (table 2).

Therapeutic genes will be introduced into the body using viral vectors – the most powerful method of delivering genetic constructs. This novel therapy that utilizes all the genes simultaniously will be used for radical life extension and for fighting decrepitude. Furthermore, each of the therapeutic genes will be tested individually. All the experiments will be conducted in 2-year old mice.

The experiments will be conducted in the following groups of experimental animals:





First of all, the efficiency of the delivery of therapeutic genes into the cells and duration of gene expression will be tested. If a tissue-specific therapy is needed, the specificity of the therapeutic construct delivery to the target tissue will be studied as well.

All groups of mice will be regularly tested for aging markers, and also the blood and adipose tissue transcriptome, proteome and metabolome will be analyzed. All age-related histological and physiological changes will be studied. Behavioral test will be performed to analyze cognitive ability and locomotor activity in mice. The average and maximum lifespan of mice will be determined. In addition, a detailed study of side effects will be performed. Mice will be compared with old mice of the control group as well as with young mice. 

Table 1. Target genes for life extending gene therapy.












































































Target gene



The impact on gene expression


Therapeutic effect
Effects on the hypothalamus
NF-кВ Expression inhibition

The inhibition of NF-KB transcription factor causes an increase in hormone production by the hypothalamus with during aging and hypothalamus rejuvenation



 


UCP2 Overexpression

Uncoupling protein 2 elevates the temperature of the hypothalamus, which is accompanied by a slight decrease in the overall body temperature and increased longevity


Systemic effect on most body cells
TERT Overexpression

The catalytic subunit of the telomerase extends the end regions of chromosomes – the telomeres, which increase the replicative potential of cells and longevity of the body


Repetitive sequences of the genome, encoding retrotransposons Expression inhibition

Inhibiting retrotransposon expression leads reduced genetic instability in old age


CRTC1 Expression inhibition

Inhibiting TOR-kinase, which promotes cell growth and proliferation, leads to increased life expectancy


FOXO3 Overexpression

A transcription factor that triggers stress response and promotes longevity


TFEB Overexpression

A transcription factor that activates autophagy and leads to longevity


ELAVL1 Overexpression

RNA – binding protein HuR stabilizes mRNA of factors regulating the cell cycle. The overexpression of HuR leads to rejuvenation of senescent cells


SIRT6 Overexpression

The overexpression of sirtuin 6 – a NAD + -dependent deacetylase, leads to an increase in life expectancy


AMPK genes Overexpression

AMPK overexpression triggers stress response and promotes longevity


Effect on senescent cells

HSV-TK


Overexpression

Herpes virus thymidine kinase promotes the transformation of a non-toxic prodrug into a toxic product. Thus, exposure to the prodrug induces death of senescent cells




 

Table 2. Target genes for gene therapy of age-related pathologies. Overexpression of these genes is necessary for the treatment of senile tissue decrepitude.




























































Target gene Tissue and delivery method

Therapeutic effect


Gene therapy research links
VEGF Systemic delivery into the blood

Vascular endothelial growth factor enhances angiogenesis (blood vessel formation)


Wang et al., 2004
BMP2, BMP7 Systemic delivery into the blood

Bone morphogenetic proteins enhance bone formation and the fracture healing process


Yue et al., 2005; Wang et al., 2008
IL-2 gene Systemic delivery into the blood

A cytokine that stimulates an immune response


Fayad et al., 2004
CREB Hippocampus

A transcription factor that in the hippocampus leads to the improvement of long-term memory formation


Mouravlev et al., 2006
IGF-1 Systemic delivery to the CNS

Insulin-like growth factor-1, whose delivery to the central nervous system (CNS) causes improvement of locomotor activity


Nishida et al., 2011
ecSOD Penis

Extracellular superoxide dismutase improves erectile function by reducing oxidative stress


Bivalacqua et al., 2003
GDNF Hypothalamus

Glial-derived neurotrophic factor that reduces obesity when delivered to the hypothalamus


Tumer et al., 2006
PVALB Heart A Ca2+- binding protein, that causes improvement of the hearts diastolic function Schmidt et al., 2005


Project authors: Anastasia Shubina, Mikhail Batin, Maria Konovalenko and Alexey Moskalev.

Literature




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