One of the foremost sources of frustration and incredulity among biogerontologists, in regard to the view of their work held by others, is the public's widespread inability (or unwillingness) to appreciate how huge would be the benefit to health and to the economy arising from even modest progress in comprehensively postponing the ill health of old age, and thus how parlously inappropriate is the prevailing level of funding for biogerontology in general and for translational biogerontology in particular. For at least the past decade, there has been a positive crescendo of expressions of this point in the general-audience scientific and policy literature authored not only by renegades such as myself but by those whose mainstream credentials are second to none.
A host of explanations for people's resistance to this message are proffered perennially. Arguably the most convincing is that people are just so certain, in their own minds, that no amount of money thrown at translational biogerontology would ever actually deliver even a modest postponement of age-related ill health that they reason that such money would be wasted, even despite the argument for it. In a nutshell, they feel that any number (the benefits of success), however large, when multiplied by zero (the chance of success), is still zero. The explanation leads, of course, the supplementary question of why people are so much less willing to accept expert opinion on this topic, to wit, that the chance of success is certainly not zero.
One of the papers that caught my eye in this issue of the journal is authored by a research group mentioned a couple of years back here at Fight Aging!, when they showed a form of adult stem cell to be effective in regenerating damage to the pancreas. They are calling these stem cells "pathfinder cells" - there is something of a proliferation of such names as various groups stick labels on their work, and it is probably the case that at this point there is a great deal of overlap between types of stem cells, mechanisms for extracting them from tissue, and the names given by different researchers. This is especially true when commercial ventures are involved, for all the expected economic reasons.
Here the pathfinder group publishes on the use of their branded cell type for kidney regeneration:
Pathfinder cells (PCs) are a novel class of adult-derived cells that facilitate functional repair of host tissue. We used rat PCs to demonstrate that they enable the functional mitigation of ischemia reperfusion (I/R) injury in a mouse model of renal damage.
Female C57BL/6 mice were subjected to 30 min of renal ischemia and treated with intravenous (i.v.) injection of saline (control) or male rat pancreas-derived PCs in blinded experimentation. Kidney function was assessed 14 days after treatment. [Analysis] demonstrated that the overwhelming majority of repaired kidney tissue was mouse in origin. Rat PCs were only detected at a frequency of 0.02%. These data confirm that PCs have the ability to mitigate functional damage to kidney tissue [following injury].
Kidneys of PC-treated animals showed evidence of improved function and reduced expression of damage markers. The PCs appear to act in a paracrine fashion, stimulating the host tissue to recover functionally, rather than by differentiating into renal cells. This study demonstrates that pancreatic-derived PCs from the adult rat can enable functional repair of renal damage in mice. It validates the use of PCs to regenerate damaged tissues and also offers a novel therapeutic intervention for repair of solid organ damage in situ.
This behavior has been seen in a range of stem cell transplant studies: regeneration is not occurring because the transplanted stem cells are building new tissue, but rather because they alter the local environment and deliver orders to existing local cell populations. At some point in the future, this whole class of treatment will cease to involve cells, and therapies will consist of only the necessary signals - but there's a way to go yet in order to achieve that goal.