Genes controlling insulin ‘alter’ body clock

Washington, Sept 18 (ANI): Scientists at University of California, San Diego have identified certain insulin-regulating genes that can also alter the timing of the body clock.

They said that the findings can lead to new approaches to treating disorders such as metabolic syndrome that can result, at least in part, from chronic disruption of the sleep-wake cycle.

“People knew that the clock regulates many different processes, but what they didn’t realize what that when you tweak those processes, it feeds back and alters the clock,” said Steve Kay, Dean of the Division of Biological Sciences at the University of California, San Diego, who led the study along with John Hogenesch of the University of Pennsylvania.

A molecular clock controls daily physiological rhythms in many types of cells, even cells grown in culture.

By engineering cultured cells to glow yellow when a particular clock gene switched on, the team made the cycle visible. They then interfered with every human gene to see which would shift the clock. They found that hundreds altered the timing.

“We just suddenly discovered 350 new genes that affect the clock that weren’t known before,” Kay said.

However, subsequent screening to confirm the genes’ effect on a second clock gene narrowed the list to 200.

Seven genes involved in insulin control also influenced the rhythms of the clock.

“What came out very strongly was this close relationship between circadian regulation and insulin signalling. There’s a reciprocal relationship between circadian dysfunction and metabolic dysfunction,” said Kay.

The researchers suggest that genetically altered mice with malfunctioning clocks become obese and develop diet-induced diabetes.Understanding this close relationship between circadian regulation and metabolic homeostasis should provide novel ways of identifying new therapies for metabolic disease,” Kay added.

The study appears in journal Cell. (ANI)

Study on sheep shows link between personality, survival, and reproductive success

Washington, September 16 (ANI): Canadian researchers have established a link between personality, survival, and reproductive success by carrying out a study on male bighorn sheep.

Denis Reale, a professor in the Department of Biological Sciences at UQAM and Canada Research Chair in Behavioural Ecology, says that the new study offers insight into personality differences in animals and humans, from an evolutionary perspective.

Since 1969, several teams of researchers have been studying this population of bighorn sheep in Alberta, Canada. They have collected considerable data over the years.

Working in collaboration with researchers from the University of Sherbrooke and the University of Alberta, Reale identified the rams in terms of boldness and docility.

The researchers then conducted paternity tests to determine which rams were reproducing.

They point out that in a system like that of bighorn sheep where there is strong competition among the males for impregnating females, large size and high dominance status are normally key factors in a male’s success.

Males usually attain these conditions in the prime of life, between 6 and 12 years, the researchers say.

However, the paternity tests showed that some young males manage to fertilize females.

The researchers also concentrated on the risk associated with participation in the rut-males can be injured or fall from a cliff in fighting.

Reale and his colleagues hypothesized that the young males that manage to reproduce would be the boldest and most combative, and analysis of the data confirmed it.

However, in exchange for sexual precocity and risk-taking, these rams often die younger than their more docile peers. The latter, instead, invest in the long term, breed later and reach an older age.

Based on their observations, the researchers came to the conclusion that their findings indicate a variation in the personalities and life histories of the population, with two extreme types: one that could be characterised as “live fast and die” and the other as “slow and steady wins the race”.

Depending on their personality, the males managed to breed and to transmit their genes, but in different ways.

The study demonstrates that personality has a direct influence on the lifestyle of individuals.

A research article describing the study has been published in the Journal of Evolutionary Biology. (ANI)

No toxic substance found in Urumqui’s latest syringe attack victims’ body

Urumqui, Sep. 14 (ANI): The blood samples of Urimqui’s latest syringe attack victims showed no trace of radioactive, toxic or viral substances, such as AIDS, an expert at a Beijing-based laboratory has said.

However, Director of Disease Control and Biological Security Office with China’s Academy of Military Medical Sciences, Qian Jun, has said that the victims have showed signs of depression.

“Although no radioactive or toxic substances were found, some patients showed various levels of anxiety and depression and have been recommended for psychological counselling,” China daily quoted Quian, as saying.

Meanwhile, the first group of syringe attack suspects were prosecuted in Urumqi, capital of the Xinjiang Uygur autonomous region.

At least 500 cases of attacks have surfaced in the city since mid-August.

Two men and a woman were given sentences ranging from seven to 15 years in jail for syringe stabbings or robberies in which they threatened their victims with needles.

The court sentenced 19-year-old Yilipan Yilihamu to 15 years in prison for injecting a woman with a hypodermic needle on August 28 at a roadside fruit stall. (ANI)

Xinjiang riots: Urumqi party chief, Xinjiang police chief removed

Urumqi, Sep. 6 (ANI): In the aftermath of Xinjiang riots that erupted on July 5, the party chief of Urumqi and police chief of northwest China’s Xinjiang Uygur Autonomous Region have been sacked.

According to a decision by the CPC Xinjiang Autonomous Regional Committee, Li Zhi, secretary of the Urumqi Municipal Committee of the Communist Party of China (CPC), was replaced by Zhu Hailun.

Xinjiang’s police chief Liu Yaohua was also replaced by Zhu Changjie, party chief of Xinjiang’s Aksu Prefecture, Xinhua reports.

Fresh protests broke out this week after hundreds of Urumqi residents said that they were attacked by syringes. Five people were killed in the following protests.

Local hospitals had dealt with 531 victims of hypodermic syringe stabbings by Thursday, 106 of whom showed obvious signs of needle attacks.

Chinese military medical experts on Saturday ruled out the possibility that radioactive substance, anthrax and toxic chemical were used in recent syringe attacks in Urumqi City.

“According to the preliminary test results, such possibilities can be ruled out,” said Qian Jun, director of Disease Control and Biological Security Office with China’s Academy of Military Medical Sciences.

Samples had been sent to Beijing for further test, he added.

Xinjiang police has captured 25 suspects amid the syringe scare. (ANI)

Indian-origin scientists find novel therapeutic target for autoimmune diseases

London, Sept 2 (ANI): A research team led by Indian-origin scientists from University of Michigan have discovered a new mechanism that would help in future therapies for conditions ranging from autoimmune diseases to organ transplants to cancer.

U-M biochemistry professor Ruma Banerjee and her colleagues have identified a mechanism that keeps a check on aggressive immune cells that can attack the body’s own cells.

They found that immune system’s regulatory T cells influence aggressive immune cells by regulating the chemical environment between cells.

“Now we know that the redox environment outside the cell is a very important dynamic. It regulates cell function,” Nature quoted Banerjee as saying.

The processes known as redox chemistry are fundamental to the way cells derive and consume energy.

She said that regulatory T cells appear to alter the chemical environment around their aggressive cousins, known as autoreactive T cells, which either curb them or cause them to proliferate.

This mechanism is likely to be involved in inflammatory bowel disease (IBD) and ulcerative colitis.

The study conducted over live mouse immune cells showed that important redox communication occurs between dendritic cells, which are the first immune cells to detect a foreign agent, and autoreactive T cells.

Dr Sanjay Garg, a research investigator in the U-M Department of Biological Chemistry, said that the dendritic cells alter the chemical environment outside cells in a way that promotes activation of the T cells.

But then T regulatory cells “intervene in the redox chatter” and suppress that effect.

Banerjee insists that she needs to conduct more study to fully understand the process before they can use their insights to block or encourage T regulatory cell activity in animal studies of IBD or another autoimmune disease.

The study appears in Nature Chemical Biology. (ANI)

Songs help skylarks differentiate between neighbours and strangers

Washington, Aug 28 (ANI): Through their songs, skylarks can differentiate between friendly neighbours and dangerous strangers, says a new study.

The study, conducted by scientists at Queen Mary, University of London, showed that male skylarks learn to recognize local dialects in their neighbours’ individual songs, remember where each neighbour is supposed to be and reprimand intruders who don’t belong in the neighbourhood.

Dr Elodie Briefer, a postdoctoral researcher at Queen Mary’s School of Biological and Chemical Sciences and her colleagues at the University of Paris South found that skylark neighbours are tolerated if they stay in their own territory, whereas strangers – skylarks who belong to another neighbourhood – are attacked if they intrude too close to the nest.

Researchers also observed the birds’ reactions when they heard the recorded song of another skylark from different directions.

The study showed how neighbouring birds who travel too far from their regular territory – a move which is seen as threatening – also run the risk of being attacked.

Males skylarks fiercely guard their chosen home territory, the area of land where they make their nest and hunt for food.

The size and position of the male’s territory is also important as female birds check it out before deciding who is going to make the best father to her chicks.

Each skylark will usually have several neighbours, living in territories that border his own.

Bird songs are among the most complex sounds produced by animals and the skylark (Alauda arvensis) is one of the most complex of all.

The songs are composed of ‘syllables’, consecutive sounds produced in a complex way, with almost no repetition.

The male skylark can sing more than 300 different syllables, and each individual bird’s song is slightly different.

The new research found that the songs of neighbouring skylarks share more syllables with each other than they do with strangers, like a dialect.

“This may have evolved because it is safer for the birds to live close together, but they need a way to keep intruders out. By sharing a local dialect in their song, they can keep an ear out for other birds that live nearby and kick any strangers out of the neighbourhood,” she said.

The study has been published in the Springer journal Naturwissenschaften. (ANI)

Genetic discovery could pave way for obesity, diabetes treatments

Washington, Aug 27 (ANI): Researchers at University of Central Florida have identified a new genetic mechanism that controls the body’s fat-building process, paving way for treatments for obesity and type 2 diabetes.

The discovery has the potential to help hundreds of millions of people and dramatically cut health care costs.

Led by Pappachan Kolattukudy, director of UCF’s Burnett School of Biomedical Sciences in the College of Medicine, found that a gene called MCPIP (Monocyte Chemotactic Protein-1 Induced Protein) controls the development of fat cells.

Until now, a different protein, known as peroxisome proliferator-activated receptor gamma (PPAR gamma), has been universally accepted as the master controller of fat cell formation, known as adipogenesis.

But the new findings has opened new doors for scientists looking forward to develop drugs that could benefit the more than 300 million people worldwide who are clinically obese, and who have much higher risks of suffering from chronic disease and disability.

Besides, it is projected that more than 300 million people will be diabetic by the year 2025.

Kolattukudy said MCPIP is potentially an ideal target for drugs that would prevent the body from becoming resistant to insulin and prone to type 2 diabetes.

“Our research has shown that MCPIP is a regulator of fat cell formation and blood vessel formation that feeds the growing fat tissue. Therefore, a drug that can shut down its function can prevent obesity and the major inflammatory diseases resulting from obesity, including diabetes and cardiovascular diseases,” the expert said.

For the study, the researchers introduced MCPIP to living cells from mice that had been stripped of the PPAR gamma gene and found that the cells still completed the developmental process necessary to build fat.

Now, the researchers are planning to explore chemical combinations to discover drugs that are effective at shutting down the novel gene.

The development of new drugs that can block or slow down the formation of MCPIP likely would take several years.

The findings will be published in the October issue of the Journal of Biological Chemistry. (ANI)

Why people walk in circles when lost

Washington, Aug 21(ANI): It’s true: When people are lost, they walk in circles. That’s the conclusion of a new research which has also found the reason behind it.

Scientists in the Multisensory Perception and Action Group at the Max Planck Institute for Biological Cybernetics in Tübingen, led by Jan Souman and Marc Ernst, have presented the first empirical evidence that people really walk in circles when they do not have reliable cues to their walking direction.

The study has been published in the journal Current Biology.

The boffins examined the walking trajectories of people who walked for several hours in the Sahara desert (Tunisia) and in the Bienwald forest area (Germany). They used the global positioning system (GPS) to record these trajectories.

The results showed that participants were only able to keep a straight path when the sun or moon was visible. However, as soon as the sun disappeared behind some clouds, people started to walk in circles without even noticing it.

Speaking about the study, Jan Souman said: “One explanation offered in the past for walking in circles is that most people have one leg longer or stronger than the other, which would produce a systematic bias in one direction. To test this explanation, we instructed people to walk straight while blindfolded, thus removing the effects of vision. Most of the participants in the study walked in circles, sometimes in extremely small ones (diameter less than 20 metres).”

However, it turned out that these circles were rarely in a systematic direction. Instead, the same person sometimes veered to the left, sometimes to the right. Walking in circles is therefore not caused by differences in leg length or strength, but more likely the result of increasing uncertainty about where straight ahead is.

“Small random errors in the various sensory signals that provide information about walking direction add up over time, making what a person perceives to be straight ahead drift away from the true straight ahead direction,” according to Souman.

Marc Ernst, Group Leader at the MPI for Biological Cybernetics, added: “The results from these experiments show that even though people may be convinced that they are walking in a straight line, their perception is not always reliable. Additional, more cognitive, strategies are necessary to really walk in a straight line.

“People need to use reliable cues for walking direction in their environment, for example a tower or mountain in the distance, or the position of the sun.” (ANI)

Stressed crops emit more methane emissions than previously thought

Washington, August 18 (ANI): Scientists at the University of Calgary (U of C) in Canada have found that methane emission by stressed crops could be a bigger problem in global warming than previously thought.

According to a U of C study, when crops are exposed to environmental factors that are part of climate change – increased temperature, drought and ultraviolet-B radiation – some plants show enhanced methane emissions.

Methane is a very potent greenhouse gas; 23 times more effective in trapping heat than carbon dioxide (CO2).

“Most studies just look at one factor. We wanted to mix a few of the environmental factors that are part of the climate change scenario to study a more true-to-life impact climate change has on plants,” said David Reid, a professor in the Department of Biological Sciences, who co-authored a paper with research associate Mirwais Qaderi in the advanced on-line edition of the journal Physiologia Plantarum.

Reid and Qaderi analyzed methane emissions from six important Canadian crops – faba bean, sunflower, pea, canola, barley and wheat – that were exposed to combinations of three components of global climate change: temperature, ultraviolet-B radiation and water stress (drought).

What they found was troubling.

These stresses caused plants to emit more methane. In a warmer, drier world, methane might be a bigger contributor in global warming than previously thought.

When it comes to the greenhouse effect, methane could be considered the misunderstood and often overlooked orphan greenhouse gas.

Much of the attention has been focused on carbon dioxide, but more recently it has been realized that methane should also be considered as a very significant greenhouse gas.

Its concentrations have more than doubled since pre-industrial times.

While the growth rate of methane concentrations has slowed since the early 1990s, some scientists say this is only a temporary pause.

“Our results are of importance in the whole climate warming discussion because methane is such a potent greenhouse warming gas,” said Qaderi.

“It points to the possibility of yet another possible feedback phenomena which could add to global warming,” he added. (ANI)

Seals quickly respond to gain and loss of habitat under climate change

Washington, July 10 (ANI): A new study has indicated that seals can quickly respond to gain and loss of habitat under climate change.

The study was conducted by an international research team, including post-doctorate Dr Mark de Bruyn and collaborators from the US, South Africa and Italy, led by Professor Rus Hoelzel from the School of Biological and Biomedical Sciences, Durham University.

It revealed that Southern Elephant seals responded rapidly to climate and habitat change and established a new breeding site thousands of kilometres from existing breeding grounds.

The scientists found that when the Antarctic ice sheets of the Ross Sea Embayment retreated in the Holocene period 8,000 years ago, elephant seals adopted the emergent habitat and established a new population which flourished.

DNA sequences from the ancient remains of seals from the now extinct Antarctic colony showed high levels of genetic diversity, probably due to the very large population size sustained there.

According to Professor Rus Hoelzel, “We’ve shown how a highly mobile marine species responded to the gain and loss of new breeding habitat.

“The new habitat was quickly adopted, probably because seals migrate annually into Antarctic waters to feed. However, when the ice returned and the habitat was lost, only a small proportion returned to the original source population. The Antarctic population crashed and much diversity was lost,” he said.

This habitat was released after the retreat of the grounded ice sheet in the Ross Sea Embayment 7,500-8,000 years ago, and is within the range of modern foraging excursions from the Macquarie Island colony.

Using ancient mtDNA and evolutionary models, the research team tracked the population dynamics of the now extinct colony and the connectivity between this and modern breeding sites.

The team found clear signs of rapid expansion in the new colony 8,000 years ago.

This was followed by directional migration away, coupled with a loss of diversity 1,000 years ago, when the sea ice is thought to have expanded.

The data suggest that the new colony seals came initially from Macquarie Island, and that some returned there, but in much smaller numbers, when the new colony habitat was lost 7,000 years later.

“The seals that discovered the new breeding site had things good, because food was abundant and nearby, however when the ice returned, the new colony collapsed and only a few seals made it back to their original home,” Hoelzel said. (ANI)

Biological ‘fountain of youth’ found in new world bat caves

Washington, July 1 (ANI): An Indian-origin researcher in Texas has announced a discovery that may lead to the single most important medical breakthrough in human history-significantly longer lifespans.

Writing about the finding in The FASEB Journal, VA Medical Center’s Professor Asish Chaudhuri says that proper protein folding over time in long-lived bats explains why they live significantly longer than other mammals of comparable size, such as mice.

“Ultimately we are trying to discover what underlying mechanisms allow for some animal species to live a very long time with the hope that we might be able to develop therapies that allow people to age more slowly,” said the senior researcher.

His team made this discovery by extracting proteins from the livers of two long-lived bat species-Tadarida brasiliensis and Myotis velifer-and young adult mice.

The researchers exposed the livers extracted to chemicals known to cause protein misfolding.

After examining the proteins, they found that the bat proteins exhibited less damage than those of the mice, indicating that bats have a mechanism for maintaining proper structure under extreme stress.

“Maybe Juan Ponce De Leon wasn’t too far off the mark when he searched Florida for the Fountain of Youth,” said Dr. Gerald Weissmann, Editor-in-Chief of The FASEB Journal.

“As it turns out, one of these bat species lives out its long life in Florida. Since bats are rodents with wings, this chemical clue as to why bats beat out mice in the aging game should point scientists to the source of this elusive fountain,” Dr. Weissmann added. (ANI)

Scientists identify alcohol-binding site in the brain

London, June 29 (ANI): Scientists at the Salk Institute for Biological Studies have a step closer to understanding how alcohol alters the way brain cells work.

The researchers say that they have identified a binding site for alcohol in an ion channel that plays a key role in several brain functions associated with drugs of abuse and seizures.

They believe that their results could lead to the development of novel treatments for alcoholism, drug addiction, and epilepsy.

Ethanol, the alcohol in intoxicating beverages, is known to alter the communication between brain cells.

“There’s been a lot of interest in the field to find out how alcohol acts in the brain,” Nature magazine quoted Dr. Paul A. Slesinger, an associate professor in the Peptide Biology Laboratory at the Salk Institute, as saying.

“One of several views held that ethanol works by interacting directly with ion channel proteins, but there were no studies that visualized the site of association,” added the lead researcher.

He says that his study has shown that alcohols directly interact with a specific nook contained within a channel protein.

According to him, this ion channel plays a key role in several brain functions associated with drugs of abuse and seizures.

In their previous research, Slesinger’s team focused on the neural function of these ion channels, called GIRK channels, which open up during periods of chemical communication between neurons and dampen the signal, creating the equivalent of a short circuit.

“When GIRKs open in response to neurotransmitter activation, potassium ions leak out of the neuron, decreasing neuronal activity,” says UCSD Biology graduate student and first author Prafulla Aryal.

While alcohols have been previously shown to open up GIRK channels, no study ever determined whether this was a direct effect or whether this was the by-product of other molecular changes in the cell.

The researchers say that the identification of the location of a physical alcohol-binding site important for GIRK channel activation could point to new strategies for treating related brain diseases.

They believe that this protein structure may be used to develop a drug that antagonizes the actions of alcohol for the treatment of alcohol dependence.

“(Alternatively) If we could find a novel drug that fits the alcohol-binding site and then activate GIRK channels, this would dampen overall neuronal excitability in the brain and perhaps provide a new tool for treating epilepsy,” says Slesinger.

A research article describing the study has been published in the journal Nature Neuroscience. (ANI)

Good male seed beetles make for bad dads

Washington, June 26 (ANI): A new study on seed beetles has shown that, contrary to predictions, males of high genetic quality are not very successful when it comes to fertilizing eggs.

The study, conducted by Swedish and Danish scientists Goran Arnqvist and Trine Bilde, found that when female mates with several males, the males of low genetic quality are the most successful in fertilizing eggs.

In almost all animals, females mate with several different males, despite the fact that a single mating is often sufficient to fertilize her eggs.

One commonly held belief is that this behaviour may allow females to choose the sperm of the male with highest genetic quality to fertilize her eggs.

Professor Goran Arnqvist from the Department of Ecology and Evolution, Uppsala University and associate professor Trine Bilde from the Department of Biological Sciences, University of Aarhus, tested this possibility directly for the first time using seed beetles and shown that it is not true.

The researchers found that, contrary to predictions, males of low genetic quality are more successful in fertilizing eggs.

Males who gained the highest share of paternity were actually males with low genetic quality. These males also fathered offspring that did less well.

“The results support the suggestion that genes that are good for males may often be bad for their mates. Therefore, in beetles at least, multiple mating does not award females with genetic benefits,” Arnqvist said.

The study is published in this week’s issue of Science. (ANI)

How eating less can help boost lifespan

London, June 25 (ANI): Scientists have long known that a restricted diet extends life. Now, researchers at the Salk Institute for Biological Studies have identified two enzymes that provide a new molecular explanation for how eating less leads to living longer.

Howard Hughes Medical Institute investigator Andrew Dillin and colleagues identified two proteins, WWP-1 and UBC-18, that link dietary restriction to longevity in roundworms.

Dillin says when researchers removed the two enzymes from the test animals, the benefits of a restricted diet disappeared.

And when those enzymes were enhanced, longevity and disease resistance increased.

The scientists say understanding how these molecules influence longevity could have implications for developing new treatments for age-related diseases.

“The only other known factor regulating longevity in response to diet restriction operates at the very end of the signaling cascade,” said Howard Hughes Medical Investigator and senior author Andrew Dillin, Ph.D., an associate professor in the Molecular and Cell Biology Laboratory.

“These two enzymes are further up the ladder, bringing us closer to the receptor that receives the signal for throwing the switch to promote a healthy lifespan,” Dillin added.

The study has been published in the June 24, 2009, advance online edition of the journal Nature. (ANI)

Early risers and night owls show different brain function

Washington, June 24 (ANI): A study conducted by University of Alberta scientists has revealed that the brains of early risers and those of nigh owls function differently.

The researchers looked at two groups of people: those who wake up early and feel most productive in the morning, and those who were identified as evening people, those who typically felt livelier at night.

They grouped the participants in accordance with the information about their habits, gathered using a standardized questionnaire.

The scientists later used magnetic resonance imaging-guided brain stimulation to test muscle torque and the excitability of pathways through the spinal cord and the brain.

They observed that the brains of early risers were most excitable at 9 a.m. That slowly decreased through the day, according to the research team.

On the other hand, say the researchers, the brains of evening people were found to be most excitable at 9 p.m.

The researchers also observed that evening people became physically stronger throughout the day, but the maximum amount of force morning people could produce remained the same.

They also found that the excitability of reflex pathways, which travel through the spinal cord, increased over the day for both groups.

The researchers say that these findings suggest that nervous-system functions are different and have implications for maximizing human performance.

A research article on the findings has been published in the Journal of Biological Rhythms. (ANI)

How obesity increases diabetes risk

London, June 22 (ANI): Scientists at the Salk Institute for Biological Studies have discovered how obesity makes a person more prone to diabetes, and why thin people can become insulin-resistant.

Led by Dr. Marc Montminy, a professor in the Clayton Foundation Laboratories for Peptide Biology, the study has shown how a condition known as ER (endoplasmic reticulum) stress triggers abnormal glucose production in the liver, an important step on the path to insulin resistance.

ER stress is induced by a high fat diet, and is overly activated in obese people.

In healthy people, a “fasting switch” only flips on glucose production when blood glucose levels run low during fasting.

“The existence of a second cellular signalling cascade-like an alternate route from A to B-that can modulate glucose production, presents the potential to identify new classes of drugs that might help to lower blood sugar by disrupting this alternative pathway,” Nature magazine quoted Montminy as saying.

However, not all obese people become insulin resistant, and insulin resistance occurs in non-obese individuals, which led researchers to suspect that fasting-induced glucose production was only half the story.
“When a cell starts to sense stress a red light goes on, which slows down the production of proteins. This process, which is known as ER stress response, is abnormally active in livers of obese individuals, where it contributes to the development of hyperglycemia, or high blood glucose levels. We asked whether chronic ER stress in obesity leads to abnormal activation of the fasting switch that normally controls glucose production in the liver,” said Montminy.

A transcriptional switch called CRTC2 turns on glucose production.

Normally, CRTC2 sits outside the nucleus waiting for the signal that allows it to slip inside and do its work and after entering the nucleus, it teams up with a protein called CREB and together they switch on the genes necessary to increase glucose output.

In insulin-resistant mice, however, the CRTC2 switch seems to get stuck in the “on” position, and the cells start churning out glucose like sugar factories in overdrive.

But when the conditions of ER stress were mimicked in mice, CRTC2 moved to the nucleus but failed to activate gluconeogenesis, and instead switched on genes important for combating stress and returning cells to health.

On closer inspection, the researchers found that in this scenario CRTC2 did not bind to CREB, but instead joined forces with another factor, called ATF6a.

However, it was found that the more ATF6a is bound to CRTC2, the less there is for CREB to bind to.

“This clever mechanism ensures that a cell in survival mode automatically shuts down glucose production, thus saving energy,” said a co-author of the study.

The researchers then found the levels of ATF6a to go down when ER stress was chronically activated, compromising the cells’ survival pathway and favouring the glucose production pathway.

Hyperglycemia wins in conditions of persistent stress.

“Our study helps to explain why obese people have a stronger tendency to become diabetic. When ER stress signaling is abnormal glucose output is actually increased,” said a co-author.

“It is possible that mutations in the highly conserved CRTC2 lead to a predisposition to inappropriate gluconeogenesis,” said Montminy.

The study has been published in the advance online edition of the journal Nature. (ANI)

Now obesity increases diabetes risk

London, June 22 (ANI): Scientists at the Salk Institute for Biological Studies have discovered how obesity makes a person more prone to diabetes, and why thin people can become insulin-resistant.

Led by Dr. Marc Montminy, a professor in the Clayton Foundation Laboratories for Peptide Biology, the study has shown how a condition known as ER (endoplasmic reticulum) stress triggers abnormal glucose production in the liver, an important step on the path to insulin resistance.

ER stress is induced by a high fat diet, and is overly activated in obese people.

In healthy people, a “fasting switch” only flips on glucose production when blood glucose levels run low during fasting.

“The existence of a second cellular signalling cascade-like an alternate route from A to B-that can modulate glucose production, presents the potential to identify new classes of drugs that might help to lower blood sugar by disrupting this alternative pathway,” Nature magazine quoted Montminy as saying.

However, not all obese people become insulin resistant, and insulin resistance occurs in non-obese individuals, which led researchers to suspect that fasting-induced glucose production was only half the story.

“When a cell starts to sense stress a red light goes on, which slows down the production of proteins. This process, which is known as ER stress response, is abnormally active in livers of obese individuals, where it contributes to the development of hyperglycemia, or high blood glucose levels. We asked whether chronic ER stress in obesity leads to abnormal activation of the fasting switch that normally controls glucose production in the liver,” said Montminy.

A transcriptional switch called CRTC2 turns on glucose production.

Normally, CRTC2 sits outside the nucleus waiting for the signal that allows it to slip inside and do its work and after entering the nucleus, it teams up with a protein called CREB and together they switch on the genes necessary to increase glucose output.

In insulin-resistant mice, however, the CRTC2 switch seems to get stuck in the “on” position, and the cells start churning out glucose like sugar factories in overdrive.

But when the conditions of ER stress were mimicked in mice, CRTC2 moved to the nucleus but failed to activate gluconeogenesis, and instead switched on genes important for combating stress and returning cells to health.

On closer inspection, the researchers found that in this scenario CRTC2 did not bind to CREB, but instead joined forces with another factor, called ATF6a.

However, it was found that the more ATF6a is bound to CRTC2, the less there is for CREB to bind to.

“This clever mechanism ensures that a cell in survival mode automatically shuts down glucose production, thus saving energy,” said a co-author of the study.

The researchers then found the levels of ATF6a to go down when ER stress was chronically activated, compromising the cells’ survival pathway and favouring the glucose production pathway.

Hyperglycemia wins in conditions of persistent stress.

“Our study helps to explain why obese people have a stronger tendency to become diabetic. When ER stress signaling is abnormal glucose output is actually increased,” said a co-author.

“It is possible that mutations in the highly conserved CRTC2 lead to a predisposition to inappropriate gluconeogenesis,” said Montminy.

The study has been published in the advance online edition of the journal Nature. (ANI)

Targets to preserve world’s forests will not be met by 2010: Study

London, May 23 (ANI): A new analysis has revealed that the attempts to preserve 10 per cent of the world’s forests are falling short, and targets set under the Convention on Biological Diversity (CBD) will not be met by 2010.

The study shows that only 7.7 percent of the globe’s 20 major types of forests are currently protected, according to categories established by the International Union for Conservation of Nature (IUCN), headquartered in Gland, Switzerland.

The study is primarily based on the United Nations’ Food and Agriculture Organization’s definition of a forest-that is, an area of land more than 0.5 hectares in size with more than 10 per cent canopy cover.

“According to our analysis, the CBD targets will not be met,” Nature magazine quoted Neil Burgess, a conservation scientist at the University of Cambridge, UK, and one of the study’s authors, as saying.

In 2004, a total of 191 countries, excluding the United States, agreed to the CBD target of 10 percent.

Burgess said that although 7.7 percent is “reasonably good”, CBD signatories agreed to 10 percent “because it was thought this level of protection was necessary for biodiversity conservation”.

According to him, it is now recognized that protecting forests is also important for efforts to stabilize climate change, “so if we are failing to meet the target it could be even worse for climate stabilization than for biodiversity.”

The study found that 65 percent of the ecoregions have less than 10 percent of their forests protected.

In fact, the highest level of protection-with more than 50 per cent of forest protected-was found in ecoregions in parts of the Amazon, southeast Asia and Alaska.

According to Burgess, it is “good news” that many of the most important areas for biodiversity are being protected at a level above the 10 percent target.

The group used data from an existing map, published in 2000, of global forest cover from the United Nations Environment Programme’s World Conservation Monitoring Centre in Cambridge, UK. The researchers updated this map using satellite data collected in 2005.

John Healy, a forest ecologist at the University of Wales, Bangor, said that the study was important because it looked at forest protection in ecoregions and by forest type, rather than just total forest cover.

However, he added: “The reality is we don’t know whether the protection status is being enforced on the ground.” (ANI)

Poorly regulated US wildlife trade threatens public health and ecosystems

Washington, May 2 (ANI): In a new report, a team of scientists has determined that the poorly regulated US wildlife trade can lead to devastating effects on ecosystems, native species, food supply chains and human health.

The report has been made by scientists from the Wildlife Trust, Brown University, Pacific Lutheran University, the Centers for Disease Control and Prevention, and the Global Invasive Species Programme.

According to the scientists, the poorly regulated US wildlife trade can lead to devastating effects on ecosystems, native species, food supply chains and human health.

“As our world, in many senses, grows smaller and smaller with the ease of international travel, the network of connections has increased, facilitating the spread of diseases,” said Rita Teutonico, senior advisor for integrative activities in the National Science Foundation’s (NSF) Directorate for Social, Behavioral and Economic Sciences (SBE).

“These scientists report a pattern of trade in wildlife that includes a very large number of animals, coupled with a poor understanding of what species are traded,” said James Collins, NSF Assistant Director for Biological Sciences.

“The findings highlight the need for further research because of the unknown effects these animals and their pathogens can have on native organisms,” he added.

A global trade in wildlife generates hundreds of billions of dollars each year.

The researchers report that during a six-year period from 2000 through 2006, the US imported more than 1.5 billion live animals.

“That’s more than 200 million animals a year – unexpectedly high,” said scientist Peter Daszak, president of the Wildlife Trust, who co-led the research.

The animals collected were from wild populations in more than 190 countries around the world, and were intended for commercial sale in the U.S. – primarily in the pet trade.

“This incredible number of imports is equivalent to every single person in the US owning at least five pets,” said biologist Katherine Smith of Brown University, co-leader of the study.

More than 86 percent of shipments contained animals that were not classified to the level of species, making it impossible to assess the full diversity of animals imported, or calculate the risk of non-native species introductions or disease transmission.

“Shipments are coming in labeled ‘live vertebrate’ or ‘fish’,” said Daszak. “If we don’t know what animals are in there, how do we know which are going to become invasive species or carry diseases that could affect livestock, wildlife – or ourselves?” he added.

“The threat to public health is real, as the majority of emerging diseases come from wildlife,” said Smith. (ANI)

Soon, a ‘love potion’ that may help couples communicate better

Washington, Apr 30 (ANI): Relationships are tricky. Most of the people think at some point that communicating positively with their partners when discussing stressful issues, like home finances, is an impossible task. But, worry not, for Swiss researchers are working on a “love potion” that will drive away all such conflicts.

Researchers have begun exploring the benefits of oxytocin for helping couples communicate better.

Oxytocin has been touted as beneficial for reducing anxiety, producing feelings of well-being, empathy, bonding, and sexual arousal.

In its May 1st issue, Biological Psychiatry, published by Elsevier, includes a paper by Swiss researchers that have investigated the effects of oxytocin, the “love hormone,” on human couple interactions.

They recruited adult couples who received oxytocin or placebo intranasally before engaging in a conflict discussion in the laboratory.

Oxytocin increased positive communication behavior in relation to negative behavior and reduced salivary cortisol, i.e., their stress levels, compared to placebo.

“We are just beginning to understand the powerful effects of hormones and chemicals released by the body in the context of important social interactions,” commented John Krystal, M.D., the editor of Biological Psychiatry.

“As this knowledge grows, the question of how to best use our developing capacities to pharmacologically alter social processes will become an important question to explore,” he added.

Author Beate Ditzen, Ph.D., noted that this was the first study of its kind and important because it evaluated real-time natural couple behavior in the laboratory.

“[Oxytocin] might help us to pronounce the effects of a standard treatment, such as cognitive behavioral therapy, by possibly making the benefits of social interaction more accessible to the individual. But it probably will not replace these standard treatments,” the expert added.

They clarify that this study does not show that oxytocin should currently be used as a treatment itself and the effects of repeated administration have not been evaluated in humans. (ANI)