Toward conditional pharmacological immortalization
Combinatorial treatment of three compounds restored functions and proliferation of replicatively old cells within 3 days. An increase in RLS (50-100%) has been achieved. The combination may extend the chronological lifespan as well.
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Background
Rapamycin, caloric restriction, and mild hypoxia are the most proven ways to extend chronological lifespan in different species, from yeast to mammals. All these methods also prolong the viability and replicative lifespan (RLS) of mammalian cells in tissue culture. Therefore, a reciprocal conclusion can be drawn that if a substance prolongs the replicative lifespan, it will extend the chronological lifespan. Meaning that a pharmacological treatment that restores original cell function and proliferation in tissue culture may change back tissue-specific gene expression and corresponding proteome in the old organism, therefore rejuvenating it. Primary human cell cultures can last for 50-55 population doublings in tissue culture. Cells isolated from rat tissues have shorter doubling potency, usually around 20-30 cell divisions. Rapamycin or calorie restriction usually adds 10 to 30% of the average replicative life span. None of them separately or in combination with any drugs or tissue culture conditions can generate reversible, immortalized cell phenotype.
Project Details
A combinatorial treatment was identified that if applied to replicatively old cells restored their morphology and proliferative activity. It consists of three small molecules with known mechanisms of action: E, D, and B. Treatment of replicatively old (~45-50 PD, population doublings) skin (or lung) fibroblasts resulted in quick (72 hours) restoration of original fibroblasts morphology of individual cells followed by the formation of normal cell colonies with the classic "fingerprint" pattern (Fig.1, video recording is available). If treatment had started early, then a substantial increase in RLS has been achieved. To validate the observed result on a different animal model, different tissues were collected from young (six days old) and adult (1.5 years old) rats (Sprague-Dawley or Gunn) and primary cell culture were established. As a result, in several independent experiments, a substantial increase in replicative life span was observed with possible conditional immortalization (Fig. 2). Mechanism. The compounds that were used for the combinatorial treatment are well-known and some of them have a well-established mechanism of action. Compound D clears cytoplasmic DNA in senesced cells very effectively. Based on compounds E and B chemical structure, two mechanisms of drug action are under consideration: 1) Restoration of lysosomal function: intralysosomal pH, or lysosomal dynamic; 2) Modulation of eIF5a activity by alternative lysine modification.
Project Timeline
Combinatorial treatment, worms
Required Funding$1
Statusongoing
Duration4 MonthsEvaluation of the effect of the drug combination on the chronological life span of wild-type C. elegans: 1) solid surface, 2) liquid medium
Combinatorial treatment, mouse, aged
Required Funding$1
Statusplanned
Duration12 MonthsA study to determine the effect of a drug combination on the lifespan of pre-aged mice: 1) Strain, 2) heterogeneous animals.
Combinatorial treatment, mouse, 6 month old
Required Funding$1
Statusplanned
Duration36 MonthsA study to determine the effect of a drug combination on the lifespan of mice: 1) Strain, 2) heterogeneous animals.