Chronic inflammation is a bad thing, walking hand in hand with the frailties and degenerations of aging. Rising inflammation contributes to a very broad range of fatal age-related conditions, and the progressive decline of the immune system itself causes ever greater chronic inflammation, even as it fails to protect the body from pathogens and errant cells. Further, visceral fat tissue is a potent source of inflammation, and this is one of the mechanisms thought to link excess fat with lowered life expectancy and greater risk of age-related disease.

There is plenty in the Fight Aging! archives on the subject of inflammation and its role in aging. To pick a handful of examples:

• Avoid Chronic Inflammation
• Inflammation and the Damage of Aging
• The Importance of Inflammation in Aging
• More Visceral Fat Means More Inflammation
• Inflammation and Life Span Differences Between Species

Some of the best known genetically engineered mutant mice with extended longevity are those in which growth hormone and its receptor are suppressed. They are small, need careful husbanding because they don’t generate enough body heat to survive well on their own, and live 60-70% longer than ordinary members of their species. As noted in the following review paper, reduced inflammation has some role to play in this extended healthy life span:

Growth hormone, inflammation and aging:

The last 200 years of industrial development along with the progress in medicine and in various public health measures had significant effect on human life expectancy by doubling the average longevity from 35-40 to 75-80. There is evidence that this great increase of the lifespan during industrial development is largely due to decreased exposure to chronic inflammation throughout life. There is strong evidence that exposure of an individual to past infections and the levels of chronic inflammation increase the risk of heart attack, stroke and even cancer.

Centenarians represent exceptional longevity in human populations and it is already known that many of these individuals are escaping from major common diseases such as cancer, diabetes etc. There is ongoing interest in investigating the mechanisms that allow these individuals to reach this exceptional longevity. There are several animal mutants used to study longevity with hope to determine the mechanism of extended lifespan and more importantly protection from age related diseases. In our laboratory we use animals with disruption of growth hormone (GH) signaling which greatly extend longevity.

Mutant animals characterized by extended longevity provide valuable tools to study the mechanisms of aging. Growth hormone and insulin-like growth factor-1 (IGF-1) constitute one of the well-established pathways involved in the regulation of aging and lifespan. Ames and Snell dwarf mice characterized by GH deficiency as well as growth hormone receptor/growth hormone binding protein knockout (GHRKO) mice characterized by GH resistance live significantly longer than genetically normal animals.

During normal aging of rodents and humans there is increased insulin resistance, disruption of metabolic activities and decline of the function of the immune system. All of these age related processes promote inflammatory activity, causing long term tissue damage and systemic chronic inflammation. However, studies of long living mutants and calorie restricted animals show decreased pro-inflammatory activity with increased levels of anti-inflammatory adipokines such as adiponectin. At the same time, these animals have improved insulin signaling and carbohydrate homeostasis that relate to alterations in the secretory profile of adipose tissue including increased production and release of anti-inflammatory adipokines.

This suggests that reduced inflammation promoting healthy metabolism may represent one of the major mechanisms of extended longevity in long-lived mutant mice and likely also in the human.

Source:
http://www.fightaging.org/archives/2012/10/on-inflammation-in-mouse-longevity-mutants.php

Source:
http://www.longevitymedicine.tv/on-inflammation-in-mouse-longevity-mutants/

Recommendation and review posted by G. Smith

Spermidine has been noted to boost autophagy and promote greater longevity to some degree in laboratory animals. Its activities are in the process of being advanced by some researchers as candidate drug mechanisms for slowing aging. Given that, it makes sense for researchers to investigate spermidine levels in longer lived individuals to see if there is any association:

Polyamines (putrescine, spermidine and spermine) are a family of molecules deriving from ornithine, through a decarboxylation process. They are essential for cell growth and proliferation, stabilization of negative charges of DNA, RNA transcription, translation and apoptosis.

Recently, it has been demonstrated that exogenously administered spermidine promotes longevity in yeasts, flies, worms and human cultured immune cells. Here, using a cross-sectional observational study, we determined whole-blood polyamines levels from 78 sex-matched unrelated individuals divided into three age groups: group 1 (31-56 years, N=26, mean age: 44.6±6.07), group 2 (60-80 years, N=26, mean age: 68.7±6.07) and group 3 (90-106 years, N=26, mean age: 96.5±4.59).

Polyamines total content is significantly lower in group 2 and 3 compared to group 1. Interestingly, this reduction is mainly attributable to the lower putrescine content. Group 2 displays the lowest levels of spermidine and spermine. On the other hand, [nonagenarians and] centenarians (group 3) display significant higher median relative percentage content of spermine with respect to total polyamines, compared to the other groups.

For the first time we report polyamines profiles from whole blood of healthy [nonagenarians and] centenarians, and our results confirm and extend previous findings on the role of polyamines in determining human longevity. However, although we found an important correlation between polyamines levels and age groups, further studies are warranted to fully understand the role of polyamines in determining life-span. Also, longitudinal and nutritional studies might suggest potential therapeutic approaches to sustain healthy aging and to increase human life-span.

Link: http://dx.doi.org/10.1089/rej.2012.1349

Source:
http://www.fightaging.org/archives/2012/10/spermidine-levels-measured-in-centenarians.php

Source:
http://www.longevitymedicine.tv/spermidine-levels-measured-in-centenarians/

Recommendation and review posted by G. Smith

Tissue engineers have been inching closer to building a kidney from stem cells in the past couple of years. Here is a recent example of the ongoing work in this field:

Investigators can produce tissues similar to immature kidneys from simple suspensions of embryonic kidney cells, but they have been unsuccessful at growing more mature kidney tissues in the lab because the kidneys’ complicated filtering units do not form without the support of blood vessels.

Now, from suspensions of single kidney cells, [researchers] have for the first time constructed “organoids” that can be integrated into a living animal and carry out kidney functions including blood filtering and molecule reabsorption. Key to their success was soaking the organoids in a solution containing molecules that promote blood vessel formation, then injecting these molecules into the recipient animals after the organoids were implanted below the kidneys. The organoids continued to mature and were viable for three to four weeks after implantation.

Link: http://www.sciencedaily.com/releases/2012/10/121018184850.htm

Source:
http://www.fightaging.org/archives/2012/10/a-small-step-towards-tissue-engineered-kidneys.php

Source:
http://www.longevitymedicine.tv/a-small-step-towards-tissue-engineered-kidneys/

Recommendation and review posted by G. Smith

Many dubious arguments are fielded in support of aging and involuntary death: every status quo, no matter how terrible, gathers its supporters. This is one of the deeper flaws inherent in human nature, the ability to mistake what is for the most desirable of what is possible. A hundred thousand deaths each and every day and the suffering of hundreds of millions is the proposal on the table whenever anyone suggests that human aging should continue as it is.

Massive campaigns of giving and social upheaval have been founded on the backs of a hundredth of this level of death and pain – but the world has a blindness when it comes to aging. Such is the power of the familiar and the long-standing: only heretics seek to overturn it, no matter how horrid and costly it is.

Nonetheless, this is an age of biotechnology in which aging might be conquered. There are plans and proposals, set forth in some detail, and debate over strategy in the comparatively small scientific community focused on aging research. So arguments over whether the development of means of rejuvenation should take place at all, reserved for philosophers and futurists in the past, now have concrete consequences: tens of millions of lives and untold suffering whenever progress is delayed. It should always be feared that a society will somehow turn to block or impede research into therapies for aging – worse and more outright crimes have been committed in the past by the members of so-called civilized cultures.

One of the arguments put forward in favor of a continuation of aging and mass death is that without the threat of impending personal extinction we’d collapse into stagnation and indolence. As the argument goes, only death and an explicitly limited future gives us the incentive to get anything done, and so all progress depends upon aging to death. I state the proposition crudely, but this is the essence of the thing, flowery language or no.

This is a terribly wrong way of looking at things: it denies the existence of desire independent of need. It casts us as nothing more than some form of Skinner box, unable to act on our own. This is another example of the way in which many humans find it hard to look beyond what is to see what might be: we live in a state of enforced urgency because we are all dying, because the decades of healthy life are a time of frantic preparation for the decline and sickness that comes later. It is normal, the everyday experience, for all of us to know we are chased by a ticking clock, forced to put aside the things that we would rather do in favor of the things that we must do. We cannot pause, cannot follow dreams, cannot stop to smell the roses.

Some people seem to manage these goals, but only the lucky few – and then only by twining what they would like to do with what they must do. It’s hard to achieve that end, and it is really nothing more than an ugly compromise even when obtained. Yet like so much of what we are forced into by the human condition, it is celebrated. One more way in which what is triumphs over what might be in the minds of the masses.

Given many more healthy years of life in which to do so, we would lead quite different lives. Arguably better lives, not diverted by necessity into a long series of tasks we do not want to undertake, carried out for the sake of what will come. We could follow desire rather than need: work to achieve the aims that we want to achieve, not those forced on us. Because of aging and death, we are not free while we are alive – and in any collection of slaves there are those who fear the loss of their chains. The longer they are enslaved, the less their vision of freedom. Sadly, in the mainstream of our culture, it is those voices that speak the loudest.

Source:
http://www.fightaging.org/archives/2012/10/putting-aside-what-youd-rather-do-because-youre-dying.php

Source:
http://www.longevitymedicine.tv/putting-aside-what-youd-rather-do-because-youre-dying/

Recommendation and review posted by G. Smith

Some of the effects of aging are driven by signaling changes in important parts of our biochemistry – such as in stem cell niches, collections of cells that provide necessary support to the stem cells that maintain and repair tissue. Niches increasingly act to suppress the stem cells they contain in response to rising levels of cellular and other damage connected to aging. The stem cells themselves also suffer damage, and this evolved response is likely a way to minimize the risk of cancer at the cost of maintaining tissues, but the declining function of the stem cells so far seems to be far more a property of signals from the niche.

In the course of investigating this and similar effects, researchers have been moving blood between young and old mice. Transfusions and joining the bloodstreams of young and old mice are a way to change the signaling environment in order to see what the effects are. The outcome is that a range of measures of aging are reversed:

Experiments on mice have shown that it is possible to rejuvenate the brains of old animals by injecting them with blood from the young. … blood from young mice reversed some of the effects of ageing in the older mice, improving learning and memory to a level comparable with much younger animals.

[Researchers] connected the circulatory systems of an old and young mouse so that their blood could mingle. This is a well-established technique used by scientists to study the immune system called heterochronic parabiosis. When [researchers] examined the old mouse after several days, [they] found several clear signs that the ageing process had slowed down. The number of stem cells in the brain, for example, had increased. More important, [they] found a 20% increase in connections between brain cells.

One of the main things that changes with ageing are these connections, there are a lot less of them as we get older. That is thought to underlie memory impairment – if you have less connections, neurons aren’t communicating, all of a sudden you have [problems] in learning and memory. … the young blood most likely reversed ageing by topping up levels of key chemical factors that tend to decline in the blood as animals age. Reintroduce these and [all] of a sudden you have all of these plasticity and learning and memory-related genes that are coming back.

Link: http://www.guardian.co.uk/science/2012/oct/17/young-blood-reverse-effects-ageing

Source:
http://www.fightaging.org/archives/2012/10/more-on-young-blood-and-old-mice.php

Source:
http://www.longevitymedicine.tv/more-on-young-blood-and-old-mice/

Recommendation and review posted by G. Smith