The anti-aging market is booming as targeted breakthroughs (e.g., NMN, rapamycin) help people slow or even reverse certain signs of aging. But widespread, whole-body reversal remains a long shot.
Sinclair believes the key to reprogramming cells is knowing how to reset their state of operation. He compared the process to wiping the data from a phone and reloading it.
CRISPR-Based Gene Editing
CRISPR-Cas9 gene editing is a powerful tool that can make precise modifications to DNA. These changes can correct genetic defects, improve cellular function and extend lifespan. The technique is currently being used to treat a wide variety of conditions, including cancer, immune disorders and neurological diseases. It may also be able to reverse aging by targeting specific genes that control key biological processes.
In the lab, scientists use viruses as vessels to guide the CRISPR system to a target gene. Then, they use the Cas9 protein to cut the targeted gene. This creates a tiny hole in the genome, and it allows other cells to enter and repair the broken region. The process is quick, easy and cost-effective. It has the potential to revolutionize regenerative medicine and anti-aging research.
Scientists have also developed ways to use CRISPR to rejuvenate stem cells, the unspecialized cells that give rise to different types of tissue. Stem cells can replace damaged or dying cells, but as people age, they become less able to do so. By boosting the activity of stem cells, scientists can slow or even reverse aging.
A team of Stanford researchers has been working on a method to do just that. Their approach involves extracting stem cells from the brains of old mice and infecting them with a virus that delivers gRNAs (guide RNAs). The gRNAs target a gene known as Ichor, which is required for the production of telomeres — protective caps at the ends of chromosomes that shorten with each cell division. The scientists found that infected stem cells became more active and produced more telomeres, and that restoring telomere length reduced cellular senescence.
In addition, the team has shown that they can reactivate the telomerase enzyme in senescent cells and extend their lifespan by up to 50%. They hope that this work can be applied to human hematopoietic stem cells (HSCs), which are essential for blood cell production and transplantation. Currently, patients who receive HSCs from older donors die more often than those who get cells from younger donors.
Although these studies are promising, the biggest challenge remains ensuring the safety of CRISPR-Cas9. A single misplaced edit could accelerate aging or trigger cancer. To reduce the risk, researchers are developing next-generation systems that cut only selected DNA strands and deliver gRNA to the target cell without damaging other nearby cells. Delivery methods are also evolving, with viral vectors giving way to non-viral carriers such as lipid nanoparticles.
Yamanaka Factors
The discovery of how to “rewind” mature cells back into stem cells captivated scientists and won the 2012 Nobel Prize for Shinya Yamanaka. His discovery involved just four proteins called Yamanaka factors (Oct4, Sox2, cMyc, and Klf4) that are highly expressed in embryonic stem cells. By inducing these factors into non-embryonic cells, he was able to convert them into induced pluripotent stem cells (iPS) that can grow into any cell in the body.
Researchers are now working on using smaller amounts of these 4 factors to partially reset skin cells, so they behave more like young cells at the genetic level. This could lead to an anti-aging therapy that actually reverses aging rather than just covering up wrinkles and fine lines. This new technology will also be much safer than current stem cell treatments because it does not involve reprogramming cells into an embryonic state.
Senolytics
Senolytics are drugs that selectively eliminate senescent cells. These drugs are expected to offer a novel approach to treat multiple chronic conditions, including osteoarthritis and Alzheimer’s disease. There has been a surge of clinical trials, venture capital funding, and biotech partnerships focused on senolytics. This growth is driven by groundbreaking advancements in cellular biology and increasing interest in root-cause interventions for age-related diseases.
Senescent cells accumulate in various tissues, leading to inflammation and contributing to the development of a variety of age-related conditions. By eliminating senescent cells, senolytics can reduce inflammation and restore tissue function. Several companies are developing senolytic agents, including Unity Biotechnology and SIWA Pharmaceuticals. Although these drugs have shown senolytic activity in mice, they have yet to show similar results in humans. However, if these drugs are successful, they could significantly improve health and extend lifespan.
The most recent research on senolytics has focused on the use of small molecules and cell-free extracts to kill senescent cells. These compounds have been shown to be effective in human fibroblasts and to reduce the accumulation of senescent cells in mouse models. In addition, these compounds have been shown to increase the lifespan of mice.
Another company, Sarepta Therapeutics, is advancing a new approach to senolytics. The company is working on a drug called 318H, which has been shown to kill senescent cells in animal models. The company has completed tolerability studies in primates and is preparing an Investigational New Drug (IND) application with the FDA. If successful, 318H could be the first senolytic therapy to enter clinical trials.
While the concept of killing senescent cells may seem controversial, it is crucial to prolong lifespan. Senescent cells can trigger inflammatory responses and contribute to cancer development. By eliminating senescent cells, we can prevent the development of many age-related diseases and reduce overall healthcare costs.
A major challenge remains to translate these promising findings into a clinical treatment. A major concern is whether senolytics should be administered systemically or locally. Local administration may be less risky, but there is a concern that local injections will not stay in the target tissue. Furthermore, senescence spreads from cell to cell, so a single senescent cell could contribute to the accumulation of senescence in other cells.