Scientists have created six chemical cocktails to combat key hallmarks of aging by rejuvenating senescent cells without altering their cellular identity. Their findings will be published this month in Aging journal.
Researchers utilized real-time nucleocytoplasmic protein compartmentalization assays and transcription-based aging clocks to identify cocktails that returned NCC and genome-wide transcript profiles to their youthful states in less than seven days – thus reversing transcriptomic ageing.
What is it?
Research has demonstrated the ability to reprogram cells into pluripotency, potentially leading to cell-based therapies in the future. But reverse aging of existing cells without inducing pluripotency has proven much harder – until now! Researchers from Stanford have developed a cocktail of small molecules which, when added to fibroblasts, rejuvenate them effectively within just seven days without altering cellular identity in any way. This discovery comes after their team discovered six chemicals which restored youthful genome-wide transcript profiles and reversed transcriptomic age without alteration – without alteration.
Scientists developed high-throughput cell-based assays, real-time nucleocytoplasmic protein compartmentalization assays and transcription-based aging clocks to differentiate young from senescent cells, using these methods to screen compounds that would regenerate human fibroblasts and reverse their aging process. Their screening found that using combinations of antiseizure drugs used for migraine and mood disorders such as valproic acid along with four small molecules — such as methyl urea, lisuride, apoptosis inhibitors and GTP-cyclclose-binding protein inhibitors — effectively reversed senescent phenotypes while decreasing biological and chronological age significantly.
Researchers discovered that all six chemical cocktails induced the expression of genes involved in key epigenetic pathways involved in OSK(M)-induced iPSC reprogramming and OSK(M) iPSC generation processes such as interferon signaling, JAK-STAT signaling, cell cycle control and chromatin remodeling – with one having the greatest impact in decreasing biological and chronological age in just four days of treatment!
Researchers conducted gene set enrichment analysis (GSEA) to ascertain the pathways underlying these rejuvenating effects and found that cocktails C1 and C5 caused upregulation of metabolism-associated pathways while simultaneously decreasing hypoxia levels and multiple inflammation pathways, such as interferon signaling pathways and JAK-STAT signaling.
How does it work?
Harvard Medical School researchers have developed cocktails of chemicals that can reverse cell aging without altering genetic material. Using advanced tests to distinguish young cells from old and senescent ones in real time, then screening for molecules that rejuvenate cells to return them back to an earlier state, they identified six combinations of small molecules which rejuvenate and reverse cellular aging without inducing pluripotency that would promote excessive cell growth.
Sinclair and his team compiled a list of molecules which had previously successfully converted human somatic cells into chemically induced pluripotent stem cells (CiPSCs). They conducted 80 cocktails tests that measured compartmentalization between proteins in the nucleus and interior cell fluid (cytosol), using tests which measure compartmentalization between nucleus and interior of cell (cytosol). Cocktails which increased compartmentalization proved effective at rejuvenating old and senescent cells back into more youthful states; researchers even used transcription-based aging clock to confirm reduction of gene activity within four days of treatment!
The most successful cocktail included sodium butyrate, a histone deacetylase inhibitor; valproic acid, used to treat epilepsy; basic fibroblast growth factor and a-KG; this combination decreased cell age by three years after just four days of treatment. Although further tests must be conducted on live animals to see whether similar treatments will also reduce cellular aging; nevertheless, their discovery marks an important step toward treating age-related diseases such as cancer, neurodegenerative disorders, cardiovascular disease and obesity.
What are the benefits?
Scientists have developed an innovative solution to counter cellular aging without altering DNA, by reprogramming stem cells back to their stem cell state and reprogramming aging human tissues to their original condition. Reprogrammed stem cells then allow differentiated into various cell types for future healing or even cure for certain medical conditions and diseases. Researchers conducted advanced tests that identified six chemical cocktails which could successfully reverse senescent cells found in human tissue; their findings were published in Aging journal.
The team conducted extensive screening of over 80 small molecules to see whether any could rejuvenate senescent cells using real-time nucleocytoplasmic protein compartmentalization (NCC) assays and transcriptomic age estimates (tAgeD). Scientists discovered six cocktail combinations, C1-6, which reduced biological and chronological tAgeD estimates by over three years in less than four days while simultaneously returning genome-wide transcript profiles to more youthful states in just under 48 hours.
To confirm their results, scientists compared six cocktail treatments administered to mice and humans to see whether they shared similar molecular effects. Their analysis demonstrated that all mouse- and human-based cocktails acted upon genes associated with senescence-associated pathways like mitochondrial metabolism, lysosomal function, apoptosis and growth signaling; additionally, molecular fingerprints from cocktail treated cells resembled OSK-induced iPSCs.
After treatment with cocktail cocktails, gene activity profiles of senescent cells became much younger compared to untreated ones, and biological and chronological tAgeD scores decreased below that of non-senescent cells by several years. Researchers concluded that all cocktail treatments significantly slowed aging by several years.
Researchers evaluated six cocktail treatments for their ability to revert senescent cells back into pluripotency using an assay that measures nuclear membrane formation, finding that one chemical in Cocktail C2, VC6TF, could effectively induce conversion from senescent cells into CiPSCs.
Researchers are now testing whether their method for rejuvenating cells extends beyond lab animals and into living animals like mice. Unlike risky gene therapies, these cocktails act through epigenetics–regulating gene expression instead of altering DNA sequences–to produce lasting cellular rejuvenation effects that could replicated among human patients.
What are the risks?
Scientists are investigating ways to rejuvenate old cells, and a recent study published in Aging shows promising results. Researchers discovered that a cocktail of chemicals repressed skin cell aging by restoring compartmentalization of proteins and reversing key transcriptional signatures associated with senescence. While the research conducted was on laboratory cells only and its long-term impact is uncertain; furthermore it remains unknown if or how such cocktails could be applied to tissues and organs of living humans.
Researchers identified six chemical combinations that effectively reversed cellular senescence within seven days without altering cell identity, without altering real-time assays used to assess nuclear compartmentalization and gene activity known as the transcriptomic aging clock. These techniques revealed how these chemicals reprogrammed senescent cells into younger states by reversing signatures associated with cellular senescence such as AMPK activation, mitochondrial translation, lysosomal functions, p53 signaling and interferon responses – without changing cell identity or altering identity of their identity.
Chemical cocktails not only reverse transcriptional signatures of senescence, but they also significantly reduced estimated chronological age of cells. One cocktail in particular reduced estimated biological and chronological age by over three years after just four days – comparable to changes seen when cells underwent treatment for over one year with another therapy that restored epigenetic information.
The cocktail of small molecules was composed of drugs already available to treat certain conditions, including valproic acid (an anti-seizure medication), rapamycin (a cancer drug with anti-aging properties), metformin (a diabetes medication) and azathioprine (an immunosuppressive agent). Thus, risks associated with these cocktails are low; however more research needs to be completed prior to human trials taking place in order to ascertain how long rejuvenation effects last and ensure they don’t lead to cancerous mutations of cells.
