The SENS Research Foundation annual reports tend to arrive in the middle of the following year, and today the 2016 report was published. You can find it in PDF format at the foundation website. The story of SENS rejuvenation research, approaches that aim to repair the cell and tissue damage that causes aging, is one of growth and success over the years, a bootstrapping from idea to reality powered by the philanthropy and determined support of our community. We have come a long way and achieved a great deal. Yet there remains the upward curve ahead, and the completion of the vision of an end to aging has yet to be accomplished.
It is true that the first SENS therapies are on the way to the clinic, their commercial development funded by venture capital now, and senescent cell clearance is at the front of the pack. But equally important approaches to removing the damage that causes aging, such as the breaking of glucosepane cross-links, are still in the laboratory, still entirely funded by charitable donations, still building the infrastructure and running the tests in search of the first potential basis for a working therapy. When that first breakthrough is made, matters speed up considerable and funding comes running from many sources – but getting there is a slow grind. The more we can do to help the SENS Research Foundation thrive, the faster they can push forward with this stage of development: planting the seeds that will blossom into vast medical industries, and in doing so bring great benefit to humanity.
Since SENS Research Foundation’s founding in 2009, we’ve worked toward bringing our vision of a world free of age-related disease from concept to reality. In challenging ourselves on this front, we have likewise challenged you, our supporters. We’ve asked a lot of all of you, and not only have you accepted this challenge, you have delivered. The rejuvenation biotechnology community that has emerged over the past several years owes its existence to each and every one of you. You have become our most vocal advocates. Over 2000 of you have become our funders.
We asked you to help us change how the world researches and treats age- related disease. You did. Through the efforts of our donors, collaborators, and our advisory board, world-renowned institutions are pursuing age- related disease research specifically focused on the damage-repair paradigm. We asked you to help us move from basic research to translational research and clinical trials. You did. In 2016 we launched Project|21, our five-year plan to help move rejuvenation biotechnologies from concept to human clinical trials. Project|21 is now backed by a number of generous and forward-thinking individuals.
You asked us to follow through. We did. In lending your support, you place not only resources in our hands, but trust. We know that a world-changing nonprofit cannot operate on the power of vision alone; and we are here not just to inspire, but to deliver results. The purpose of this report is to demonstrate concrete examples of those results to you. With your help, we have taken great steps toward the establishment of a robust rejuvenation biotechnology industry and the realization of our vision. And every step we are able to take is proof of the power of your community.
Death-Resistant Cells: Toward Neutralizing the SASP
Buck Institute researchers led by Dr. Judith Campisi had shown that the presence of senescent cells alongside cancer cells can stimulate those cells to both multiply more rapidly and to spread to other parts of the body – the metastasis process, which ultimately makes most cancers so deadly. Repeating these studies in cell culture while inhibiting the senescence-associated secretory phenotype (SASP) with apigenin almost completely nullified the proliferation-stimulating and pro-metastatic effects of senescent cells on breast cancer cells. Drugs based on parts of apigenin’s structure could dampen some of the harmful effects the SASP in senescent cells. Removing these cells is the ultimate solution to these problems, and in the last year several groups have made rapid progress toward this goal. In the meantime, these studies using apigenin may demonstrate important principles from which senescent-cell-focused rejuvenation biotechnologies may be derived.
Target Prioritization of Tissue Crosslinking
Our arteries slowly stiffen with age, in substantial part because of random crosslinking of the structural proteins collagen and elastin. Developing rejuvenation biotechnologies to break these crosslinks is key to restoring youthful arterial function. To tease out the effects and relative importance of all of these different sources of crosslinking in aging tissues, the Babraham Institute team has been studying the crosslinking process in the tissues of aging mice. This has required the development and validation of new experimental methods and assays, which are now ready for use. The team has evaluated multiple tissues for crosslink presence. Importantly, some of the crosslinks that have been reported by others to accumulate in aging tissues were not detected. While further studies are needed to confirm it decisively, these results suggest that several crosslinks now believed to accumulate in aging tissues may actually be experimental artifacts.
Engineering New Mitochondrial Genes to Restore Mitochondrial Function
Free radicals derived from our energy-producing mitochondria can mutate the organelle’s DNA, leading to deletions of large stretches of the mitochondrial genome. These deletion mutations prevent the mitochondria from building various pieces of the electron transport chain (ETC), with which mitochondria generate most cellular energy. The accumulation of deletion-mutation-containing cells is a significant consequence of aging. A potential rejuvenation biotechnology to recover ETC function is the allotopic expression of functional mitochondrial genes: placing “backup copies” of all of the protein-coding genes of the mitochondria in the “safe harbor” of the nucleus, thereby giving the mitochondrion all of the proteins it needs to continue producing energy normally even when the original mitochondrial copies have been mutated.
This year, the SRF MitoSENS team reported a tremendous success: for what they believe is the first time, they have used allotopic expression to rescue the complete loss of a mitochondrially-encoded protein in a mammalian cell. A publication announced their success in the fall of 2016. The results show that their targeted and recoded ATP8 protein can be expressed from the nucleus, turned into protein in both normal and mutant cells, and efficiently targeted to the mitochondria. Furthermore, they can demonstrate functional rescue of cells. Under conditions where mutant cells die for lack of ability to produce energy, the cells with engineered allotopically-expressed proteins were able to survive and replicate. In addition to ATP8, the SRF MitoSENS team has further demonstrated expression and targeting of a second re-engineered protein, ATP6. It is proof-of-concept that ATP8 is not a special case.
Identification of the Genetic Basis of ALT in Cancer
Telomeres shorten every time a cell divides, and thus all cancers have to find a way to keep their telomeres long enough to prevent senescence or death. Most cancers use an enzyme called telomerase for this purpose, but about 10-15% of cancers use a telomerase-independent mechanism known as Alternative Lengthening of Telomeres (ALT). The ALT mechanism remains largely a mystery, and therefore the OncoSENS team at SENS Research Foundation is working hard to find new ways to attack ALT cancers. First, the team has developed and established two separate high-throughput assays measuring different ALT-specific biomarkers. These assays will finally enable cancer researchers to screen hundreds of thousands of compounds across multiple drug libraries, or even test every single one of the more than 20,000 genes in the human genome, for ways to shut down ALT cancers. In addition to their biomarker work, the team is also pursuing more targeted methods to kill ALT cancer cells.
Glucosepane Crosslinks and Routes to Cleavage
One major cause of crosslink accumulation in aging is Advanced Glycation Endproducts (AGE), and one AGE in particular, called glucosepane, is currently thought to be the single largest contributor to tissue AGE crosslinking. The Yale AGE team is studying the role of AGEs in aging, and developing novel tools and strategies for reversing AGE-mediated protein damage and develop new antibodies and reagents to enable rejuvenation research. Our pilot lab at Cambridge University found that all of the commercially-available antibodies for the major AGE-related molecules are actually highly unreliable. This is a serious impediment. The Yale glucosepane team is now tackling this problem via the novel chemistry and methods they have developed. In the last twelve months, the Yale team has made exciting progress in their work. Most notably, they have developed the first synthetic route to produce glucosepane. Their novel synthetic strategy is the first ever to provide high yields of pure samples of glucosepane, putting them (and soon other scientists) for the first time in a position to explore mechanisms through which crosslinks can be broken.
In collaboration with a colleague at Yale, they have also developed a high-throughput assay for screening proprietary libraries of organic catalysts for agents capable of breaking synthetic glucosepane. One of these libraries has already been taken forward for proof of concept, which led to the identification of several leads for catalysts that could be capable of breaking glucosepane. Beyond that, the Yale group has successfully generated proteins containing their synthetic glucosepane that can be used to identify antibodies that label glucosepane-containing proteins. These antibodies will enable the immunochemical detection of glucosepane crosslinks for a wide range of applications.
The thymus gland is responsible for the development of a class of immune cells called T-cells. As part of the degenerative aging process, the thymus shrinks in size. This process of thymic atrophy prevents the body from maturing new T-cells, progressively weakening the immune system’s ability to fight off never-before-encountered infections. Engineering new, healthy thymic tissue would help to restore the vigorous immune response of youth. SENS Research Foundation has therefore funded a Wake Forest Institute for Regenerative Medicine (WFIRM) group to apply tissue engineering techniques to the creation of functional thymic tissue to fortify or replace the aging thymus. Engineering new tissues requires a “scaffold” in which to embed cells to give them structure and functional cues, and the WFIRM group has tested different scaffolding systems: decellularized donor scaffolds and hydrogels.
In the decellularized scaffold paradigm, an organ of the type that is needed is taken from a donor, but is then stripped of its original cells and DNA, leaving behind a protein structure with low potential for immunological rejection that can be repopulated with cells taken from the new organ recipient. The WFIRM group initially began work in this paradigm using mouse organs, but they found that once decellularized, mouse thymuses lacked the rigidity to serve in that role. They accordingly moved on to the pig thymus – a species that not only worked well as an experimental system, but has some clinical potential as well. The pig is closer to humans both immunologically and in terms of size.
Catalytic Antibodies Targeting Transthyretin Amyloid
As part of the degenerative aging process, proteins that normally remain dissolved in bodily fluids become damaged, and adopt a misfolded form called amyloid. Amyloid composed of the transporter protein transthyretin (TTR) deposits in the heart and other organs with age, beginning to impair heart function. With SRF funding, the University of Texas-Houston Medical School (UTHMS) extracellular aggregate team is working to develop novel catalytic antibodies (“catabodies”) that would recognize and cleave TTR amyloid deposited in the heart and other tissues. Catabodies have the potential to be safer and more effective than conventional antibody-based immunotherapies: their catalytic activity minimizes the amount of antibody required to clear deposits from tissues, and the fact that they don’t form stable complexes with their targets or engage immune cells is expected to minimize the inflammatory side-effects seen with other experimental antibody therapies.
Work has resulted in the identification of two powerful TTR-cleaving catabodies. When tested for their ability to degrade misfolded wild-type TTR, these candidates were able to hydrolyze both soluble aggregates and deposit-like particulates, while having no effect on either TTR in its healthy, normal conformation or on a selection of fourteen other physiologically important proteins. Concentrations required to disintegrate 80% of a sample of amyloid were many hundreds of times lower than those routinely achieved in the blood using other infused antibodies. The establishment of stable cell lines will enable larger-scale production, as the team works to develop these candidates into functional rejuvenation biotechnologies.
Rejuvenation of the Systemic Environment
There might be a misunderstanding of what was really going on in parabiosis. When animals are connected, they are not just given reciprocal blood transfusions, but are surgically joined together. So in addition to receiving young blood, the old animals also have their old blood filtered through the young animals’ livers and kidneys, and diluted with the young pairmate’s own blood. Might the effects of parabiosis mostly come from the removal of toxic or suppressive factors from the old animals’ sluggish circulation instead of from the delivery of active rejuvenating factors?
To test this possibility – and to accelerate identification and testing of potential pro- and anti-rejuvenation factors in the exchanged blood – SENS Research Foundation funded Dr. Conboy and the UC Berkeley systemic environment team’s development of a novel technological platform. Using a mixture of off-the-shelf and custom 3-D printed parts, this platform enables the group to easily and safely extract blood from small animals and transfuse it quickly and directly into another animal, without the reciprocal exchange of its blood or the passage of its blood through the pairmate’s system. It thus separates the effects of the young animals’ metabolic and excretory systems from the pure effects of their blood.
The team then used the new system to repeat key parabiosis experiments from Dr. Conboy’s and others’ labs. As compared with the impact of full-on parabiosis, the effects of isolated young blood on old muscles’ ability to repair an injury were still substantial: the stem cells recovered significant regenerative powers, and less residual fibrosis remained after the wound was resolved. But by contrast, previously-reported benefits of parabiosis in the brain and the liver were either not present, or were far more modest. Another critical finding was the confirmation of suppressive factors in the old animals’ blood, which inhibited neurogenesis and other regenerative responses of young animals transfused with it. While this clearer picture of the basis of the “parabiosis effect” indicates a lower likelihood of isolating true pro-rejuvenation factors in the blood of young mice, we are nonetheless closer to being able to filter out factors responsible for suppressing the regenerative potential of an older body.
Two of the companies SENS Research Foundation has supported are moving to raise funding to move their research from the lab to clinical trials. Ichor Therapeutics announced a Series A offering to bring its Lysoclear product for age-related macular degeneration and Stargardt’s macular degeneration through Phase I clinical trials. In 2014, Ichor Therapeutics completed a material and technology transfer agreement for rights to concepts and research pioneered by SENS Research Foundation. Lysoclear, which Ichor announced in 2017, is a recombinant enzyme product based on extending SRF’s prior work that selectively localizes to the lysosomes of retinal pigment epithelium cells where A2E accumulates, and destroys it. Ongoing studies suggest that Lysoclear is safe and effective at targeting A2E, the main toxin driving these diseases, eliminating up to 10% with each dose. This product would be the first clinical candidate based on concepts and research pioneered by SENS Research Foundation.
Oisin Biotechnologies is focused on the genetic elimination of unwanted cells, but without involving the immune system. Oisin reports significant progress in showing that their vector works, efficiently transducing cells and delivering a DNA construct which can kill targeted cells on command. Oisin closed a $500K oversubscribed convertible debt round in mid-December and is working towards a substantial Series A in the next few months that would take it towards a Phase 1 clinical trial.