Category Archives: Transhuman News

Newswise BOSTON September 16, 2012 As part of their ongoing research investigating the biology of aging, the greatest risk factor for type 2 diabetes and other serious diseases, scientists at Joslin Diabetes Center have identified a new factor microRNA processing in fat tissue which plays a major role in aging and stress resistance. This finding may lead to the development of treatments that increase stress resistance and longevity and improve metabolism. The findings appear in the September 5 online edition of Cell Metabolism.

Over the past several years, it has become clear that fat cells (adipocytes) are more than just repositories to store fat. Indeed, fat cells secrete a number of substances that actively influence metabolism and systemic inflammation. Previous studies have found that reducing fat mass by caloric restriction (CR) or surgical or genetic means can promote longevity and stress resistance in species from yeast to primates. However, little is known about how CR and fat reduction produce these beneficial effects. This study investigated one type of molecular mediator change in microRNAs (miRNAs) and the processing enzymes required to make them that is influenced by aging and reversed by caloric restriction. miRNAs are involved in the formation of mature RNA.

Based on studies conducted using human cells, mice and C. elegans (a microscopic worm used as a model organism for aging studies), the researchers demonstrated that levels of multiple miRNAs, decrease in fat tissue (adipose) with age in all three species. This is due to a decrease in the critical enzyme required from converted pre-miRNAs to mature miRNAs, Dicer. In the human study, which compared the miRNA levels in preadipocytes (fat cell precusors) of young, middle-aged and older people, people aged 70 and older had the lowest miRNA levels. The fact that this change occurs in humans, mice and worms points to its significance as a general and important process, says lead author C. Ronald Kahn, MD, Chief Academic Officer at Joslin Diabetes Center and the Mary K. Iacocca Professor of Medicine at Harvard Medical School.

Caloric restriction, which has been shown to prolong lifespan and improve stress resistance in both mice and worms, prevents this decline of Dicer, and in the case of the mice, restore miRNAs to levels observed in young mice. Conversely, exposure of adipocytes to major stressors associated with aging and metabolic diseases, including toxic agents, Dicer levels decreased. Mice and worms engineered to have decreased Dicer expression in fat showed increased sensitivity to stress, a sign of premature aging. By contrast, worms engineered to overexpress Dicer in the intestine (the adipose tissue equivalent in worms) had greater stress resistance and lived longer.

Overall, these studies showed that regulation of miRNA processing in adipose-related tissues plays an important role in longevity and an organisms ability to respond to age-related and environmental stress. This study points to a completely new mechanism by which fat might affect lifespan and is the first time that anyone has looked at fat and miRNAs as factors in longevity, according to co-author T. Keith Blackwell, MD, PhD, co-head of Joslin's Section on Islet Cell and Regenerative Biology and Professor of Pathology at Harvard Medical School.

Based on this study, Blackwell suggests that finding ways to improve miRNA processing to keep miRNA levels up during aging might have a role in protecting against the stresses of everyday life and the development of age- and stress-related disease.

Dr. Kahn and the study investigators are currently working on ways to genetically control Dicer levels in the fat tissues of mice, to create mouse models that are more or less resistant to stress. We would love to find drugs that would mimic this genetic manipulation to produce a beneficial effect, says Dr. Kahn. If we can better understand the biology of aging, we might also understand how age impacts diabetes, says Kahn.

Study co-authors include Marcelo A. Mori, Prashant Raghavan, Jeremie Boucher, Stacey Robida-Stubbs, Yazmin Macotela, Steven J. Russell, and T. Keith Blackwell of Joslin; and James L. Kirkland and Thomas Thomou of the Mayo Clinic.

About Joslin Diabetes Center

Joslin Diabetes Center, located in Boston, Massachusetts, is the world's largest diabetes research and clinical care organization. Joslin is dedicated to ensuring that people with diabetes live long, healthy lives and offers real hope and progress toward diabetes prevention and a cure. Joslin is an independent, nonprofit institution affiliated with Harvard Medical School.

Read the original here:
Joslin Scientists Identify Molecular Process in Fat Cells That Influences Stress and Longevity

ScienceDaily (Sep. 26, 2012) As part of their ongoing research investigating the biology of aging, the greatest risk factor for type 2 diabetes and other serious diseases, scientists at Joslin Diabetes Center have identified a new factor -- microRNA processing in fat tissue -- which plays a major role in aging and stress resistance. This finding may lead to the development of treatments that increase stress resistance and longevity and improve metabolism.

The findings appear in the Sept. 5 online edition of Cell Metabolism.

Over the past several years, it has become clear that fat cells (adipocytes) are more than just repositories to store fat. Indeed, fat cells secrete a number of substances that actively influence metabolism and systemic inflammation. Previous studies have found that reducing fat mass by caloric restriction (CR) or surgical or genetic means can promote longevity and stress resistance in species from yeast to primates. However, little is known about how CR and fat reduction produce these beneficial effects. This study investigated one type of molecular mediator -- change in microRNAs (miRNAs) and the processing enzymes required to make them- that is influenced by aging and reversed by caloric restriction. miRNAs are involved in the formation of mature RNA.

Based on studies conducted using human cells, mice and C. elegans (a microscopic worm used as a model organism for aging studies), the researchers demonstrated that levels of multiple miRNAs, decrease in fat tissue (adipose) with age in all three species. This is due to a decrease in the critical enzyme required from converted pre-miRNAs to mature miRNAs, Dicer. In the human study, which compared the miRNA levels in preadipocytes (fat cell precusors) of young, middle-aged and older people, people aged 70 and older had the lowest miRNA levels. "The fact that this change occurs in humans, mice and worms points to its significance as a general and important process," says lead author C. Ronald Kahn, MD, Chief Academic Officer at Joslin Diabetes Center and the Mary K. Iacocca Professor of Medicine at Harvard Medical School.

Caloric restriction, which has been shown to prolong lifespan and improve stress resistance in both mice and worms, prevents this decline of Dicer, and in the case of the mice, restore miRNAs to levels observed in young mice. Conversely, exposure of adipocytes to major stressors associated with aging and metabolic diseases, including toxic agents, Dicer levels decreased. Mice and worms engineered to have decreased Dicer expression in fat showed increased sensitivity to stress, a sign of premature aging. By contrast, worms engineered to "overexpress" Dicer in the intestine (the adipose tissue equivalent in worms) had greater stress resistance and lived longer.

Overall, these studies showed that regulation of miRNA processing in adipose-related tissues plays an important role in longevity and an organism's ability to respond to age-related and environmental stress. "This study points to a completely new mechanism by which fat might affect lifespan and is the first time that anyone has looked at fat and miRNAs as factors in longevity," according to co-author T. Keith Blackwell, MD, PhD, co-head of Joslin's Section on Islet Cell and Regenerative Biology and Professor of Pathology at Harvard Medical School.

Based on this study, Blackwell suggests that "finding ways to improve miRNA processing to keep miRNA levels up during aging might have a role in protecting against the stresses of everyday life and the development of age- and stress-related disease."

Dr. Kahn and the study investigators are currently working on ways to genetically control Dicer levels in the fat tissues of mice, to create mouse models that are more or less resistant to stress. "We would love to find drugs that would mimic this genetic manipulation to produce a beneficial effect," says Dr. Kahn. "If we can better understand the biology of aging, we might also understand how age impacts diabetes," says Kahn.

Study co-authors include Marcelo A. Mori, Prashant Raghavan, Jeremie Boucher, Stacey Robida-Stubbs, Yazmin Macotela, Steven J. Russell, and T. Keith Blackwell of Joslin; and James L. Kirkland and Thomas Thomou of the Mayo Clinic.

Share this story on Facebook, Twitter, and Google:

Read the rest here:
Molecular process in fat cells that influences stress and longevity identified

Celebrating longevity: the shape of the future

The International Day of Older Persons next Monday (1 October) is a chance to consider the benefits our society gains from people living longer, says Senior Citizens Minister Jo Goodhew.

The day, which is dedicated to the celebration of older people throughout New Zealand and the rest of the world, will feature a wide range of events, including intergenerational activities and events focusing on positive ageing.

Nationally, the celebrations have already begun. There is a huge range of exciting things happening to recognise the valuable contribution older people make to our lives, our neighbourhoods, our workplaces and our communities said Mrs Goodhew.

This years international theme is Longevity: Shaping the Future. New Zealanders are living longer and healthier and it is important for individuals, employers, service providers and the Government to think about the implications and opportunities increased longevity brings. Planning is key take a minute or two to think about what you want your future to look like.

Our attitudes about ageing need to change because older New Zealanders are changing. Older Kiwis are a diverse group the majority are looking to keep active and enjoy life you only need to look at the number of older people still competing in sports events like New Zealands coast-to-coast. Older people keep volunteer organisations afloat and contribute to our communities in many ways.

By valuing and using the skills, knowledge and experience of older people, by caring for those who need it in a respectful manner, we will continue to build a great country to live in.

I encourage you to find out what is happening in your area and join me in celebrating older people. I will be attending events around the country from Christchurch to Whangarei during the week.

ends

Scoop Media

More:
Celebrating longevity: the shape of the future

Alow-calorie diet can improve your overall health, immunity and metabolism. It may even help you squeeze into an outfit youve wanted to wear for years.

But, according to a recent study, reducing your caloric intake will not increase your life expectancy.

Nature recently published the results of a 23-year-long study conducted at the National Institute of Aging in Maryland. Researchers at the NIA theorized that specific, calorie-restricted diets might prolong life in rhesus monkeys. However, to researchers surprise, dieting rhesus monkeys did not live any longer than non-dieting subjects.

WHATS A CR DIET?

The NIA study,according to the report in Nature,analyzed two primary groups of monkeys: the first control group followed a normal, yet nutritionally balanced, diet. The second followed a calorie-restricted diet, commonly known as a CR diet, in whichcaloric intake dropped by 10 to 40 percent.

I think whats really important to recognize with full calorie restriction is were studying aging and the processes of aging, NIA researcher Julie Mattison said in a phone interview.

Were studying why everything goes bad over time, and its possible that CR affects a lot of these organs.

For years, it has been believed that CR diets prolong life and improve overall health and immunity, according to the CR Society website. CR diets were also thought to stall the onset of age and weight-related diseases, such as cardiovascular disease, diabetes, arthritis and cancer.

Since the 1930s researchers have studied the benefits of CR diets in organisms such aslab rats, yeast, fruit flies and round worms. CR organisms in these studies, which often lived up to 30 to 50 percent longer than organisms with normal diets, prompted scientists to analyze the effects of CR diets in primates, including humans.

Read more here:
Losing pounds won’t gain you longevity