Dopamine Regulates Insulin Secretion Through a Complex of Receptors

In a leap forward for diabetes research, Tokyo Tech researchers reveal that the feel-good hormone, dopamine, regulates insulin secretion through a heteromeric complex of receptors, thereby providing new targets for antidiabetic medication and therapy. The study is the first to elucidate the mechanism behind dopamine's down-regulation of insulin secretion.

Diabetes is a lifelong, chronic health condition caused by abnormalities in the body's production and use of the hormone insulin. Research has shown that the feel-good hormone, dopamine (DA), plays a key role in how the body regulates the production of insulin. Typically, insulin is secreted by cells in the pancreas called 'beta-cells,' in response to glucose—a process that is aptly called 'glucose-stimulated insulin secretion (GSIS). DA negatively regulates GSIS, leading to transient changes in the body's levels of insulins. But the mechanism behind this regulation was unknown, until now.

Recently, a team led by researchers from Tokyo Institute of Technology (Tokyo Tech) uncovered the precise mechanism through which DA regulates insulin secretions. Using a technique called "total internal reflection fluorescence microscopy," they were able to reveal that DA "receptors"—proteins on cells that DA can bind to—called D1 and D2, act in concert to achieve the transient regulation of insulin.

Plant stress transformed into rapid tests for dangerous chemicals

​ Representation of the plant hormone receptor system that the team engineered to recognize new chemicals. The central yellow molecule is the natural plant hormone ABA.
Credit: Sean Cutler/UCR

Scientists have modified proteins involved in plants’ natural response to stress, making them the basis of innovative tests for multiple chemicals, including banned pesticides and deadly, synthetic cannabinoids.

Diazinon is a banned insecticide that the research team is able to detect with their new plant-hormone-based sensor system.

During drought, plants produce ABA, a hormone that helps them hold on to water. Additional proteins, called receptors, help the plant recognize and respond to ABA. UC Riverside researchers helped demonstrate that these ABA receptors can be easily modified to quickly signal the presence of nearly 20 different chemicals.

The research team’s work in transforming these plant-based molecules is described in a new Nature Biotechnology journal article.

Researchers frequently need to detect all kinds of molecules, including those that harm people or the environment. Though methods to do that exist, they are often costly and require complicated equipment.

Exploring explosives for expanding geothermal energy

Eric Robey, left, a Sandia National Laboratories mechanical engineer, and Joseph Pope, a Sandia technologist, prepare a plexiglass cube for a small-scale explosion. The information from this study could be used to create new geothermal energy systems in locations where it is currently not feasible.
Left Click Image for screen size, Right Click Image and open in new tab for full size.
 Photo by Bret Latter

Why are scientists setting off small-scale explosions inside 1-foot cubes of plexiglass? They’re watching how fractures form and grow in a rock-like substance to see if explosives or propellants, similar to jet fuel, can connect geothermal wells in a predictable manner.

Geothermal energy has a lot of promise as a renewable energy source that is not dependent on the sun shining or the wind blowing, but it has some challenges to wide adoption. One challenge is that there are only a few places in the U.S. that naturally have the right combinations of hot rock close to the Earth’s surface with available underground water. Another challenge is the initial start-up cost of drilling and connecting geothermal wells. Eric Robey, a Sandia National Laboratories mechanical engineer, is leading a team to explore if explosives can reduce those two challenges.

“Our goal was to come up with a new way of creating a geothermal fracture network that you have a clear idea where it is going to go — it’s steerable and manageable — and you are utilizing fewer resources and being more environmentally friendly,” Robey said. “This is where explosives and propellants come in. The idea is that they’ll allow us to get away from pumping a lot of fluid down the wells. We’re collaborating with Lawrence Livermore National Laboratory to model the explosions and improve the predictability of forming fracture networks.”

1.700-year-old Korean genomes show genetic heterogeneity in Three Kingdoms period Gaya

Facial reconstruction of four Ancient Korean individuals based on Ancient DNA data
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Credit: Current Biology

An international team led by The University of Vienna and the Ulsan National Institute of Science and Technology in collaboration with the National Museum of Korea has successfully sequenced and studied the whole genome of eight 1.700-year-old individuals dated to the Three Kingdoms period of Korea (approx. 57 BC-668 AD). The first published genomes from this period in Korea and bring key information for the understanding of Korean population history. The Team has been led by Pere Gelabert and Prof. Ron Pinhasi of the University of Vienna together with Prof. Jong Bhak and Asta Blazyte from the UNIST and Prof. Kidong Bae from the National Museum of Korea.

The study, published in Current Biology, showed that ancient Koreans from Gaya confederacy were more diverse than the present-day Korean population. The eight ancient skeletal remains used for DNA extraction and bioinformatic analyses came from the Daesung-dong tumuli, the iconic funerary complex of the Gaya confederacy, and from Yuha-ri shell mound; both archeological sites located in Gimhae, South Korea. 

How Tumors Make Immune Cells ‘Go Bad’

Jlenia Guarnerio, PhD

Investigators from Cedars-Sinai Cancer have discovered that cancerous tumors called soft-tissue sarcomas produce a protein that switches immune cells from tumor-attacking to tumor-promoting. The study, published today in the peer-reviewed journal Cell Reports, could lead to improved treatments for soft-tissue sarcomas.

The researchers focused on the tumor microenvironment—an ecosystem of blood vessels and other cells recruited by tumors to supply them with nutrients and help them survive.

“Tumors also recruit immune cells,” said Jlenia Guarnerio, PhD, a research scientist with Cedars-Sinai Cancer, assistant professor of Radiation Oncology and Biomedical Sciences and senior author of the study. “These immune cells should be able to recognize and attack the tumor cells, but we found that the tumor cells secrete a protein that changes their biology, so instead of killing tumor cells they actually do the opposite.”

Soft-tissue sarcoma is a rare type of cancer that forms in the muscle, fat, blood vessels, nerves, tendons and joint lining. It most commonly occurs in the arms, legs and abdomen, and kills more than 5,000 people in the U.S. each year, according to the American Cancer Society.

In comparing samples of a variety of soft-tissue sarcomas in humans and laboratory mice, Guarnerio and her team noted that most of these tumors have an abundance of immune cells called myeloid cells in their microenvironment.

“It was striking that such a large percentage of the immune cells were myeloid cells, and we thought that since they obviously weren’t killing the tumor cells, they must be doing something to promote tumor growth,” said Stephen Shiao, MD, PhD, division director of the Division of Radiation Biology, co-leader of the Translational Oncology Program and a co-author of the study. “And indeed, our analysis of tumor samples showed that many of the myeloid cells had adopted a tumor-promoting function.”

Maternal microbiome promotes healthy development of the baby

Bifidobacterium breve 
Credit: Hall Lab, Quadram Institute

A new study has found that a species of gut bacteria, known to have beneficial effects for health in mice and humans, changes the mother’s body during pregnancy and affects the structure of the placenta and nutrient transport - which impacts the growing baby.

The bacteria, Bifidobacterium breve, is widely used as a probiotic so this study could point to ways of combating pregnancy complications and ensuring a healthy start in life across the population.

The research involved scientists from the University of Cambridge, the Quadram Institute, and the University of East Anglia and is published today in the journal Cellular and Molecular Life Sciences.

Microbes in our gut, collectively called the gut microbiome, are known to play a key role in maintaining health by combating infections, and influencing our immune system and metabolism. They achieve these beneficial effects by breaking down food in our diet and releasing active metabolites that influence cells and body processes.

Little is known about how these interactions influence fetal development and the baby’s health pre-birth. To address this, Professor Lindsay Hall from the Quadram Institute and University of East Anglia, and Dr Amanda Sferruzzi-Perri and Dr Jorge Lopez-Tello from the University of Cambridge analysed how supplementation with Bifidobacterium bacteria affected pregnancy in mice.

Children who had bronchitis linked to adult lung problems

Bronchitis in early childhood has been found to increase the risk of lung diseases in middle age according to research from the Allergy and Lung Health Unit at the University of Melbourne.

Researchers found that Australian children who had bronchitis at least once before the age of seven were more likely to have lung problems in later life.

They also established that the lung diseases the children suffered from by the time they reached the age of 53 were usually asthma and pneumonia, rather than chronic bronchitis or chronic obstructive pulmonary disease.

Lead author of a paper published today in the journal, BMJ Open Respiratory Research, Dr Jennifer Perret, said the findings come from one of the world’s oldest surveys, the Tasmanian Longitudinal Health Study, which followed 8,583 people who were born in Tasmania in 1961 and started school in 1968.

“This is the first very long-term prospective study that has examined the relationship between childhood bronchitis severity with adult lung health outcomes. We have seen already that children with protracted bacterial bronchitis are at increased risk of serious chronic infective lung disease after two to five years, so studies like ours are documenting the potential for symptomatic children to develop lung conditions, such as asthma and lung function changes, up to mid-adult life,” she said.

Robotic lightning bugs take flight

Fireflies that light up dusky backyards on warm summer evenings use their luminescence for communication — to attract a mate, ward off predators, or lure prey.

These glimmering bugs also sparked the inspiration of scientists at MIT. Taking a cue from nature, they built electroluminescent soft artificial muscles for flying, insect-scale robots. The tiny artificial muscles that control the robots’ wings emit colored light during flight.

This electroluminescence could enable the robots to communicate with each other. If sent on a search-and-rescue mission into a collapsed building, for instance, a robot that finds survivors could use lights to signal others and call for help.

The ability to emit light also brings these microscale robots, which weigh barely more than a paper clip, one step closer to flying on their own outside the lab. These robots are so lightweight that they can’t carry sensors, so researchers must track them using bulky infrared cameras that don’t work well outdoors. Now, they’ve shown that they can track the robots precisely using the light they emit and just three smartphone cameras.

“If you think of large-scale robots, they can communicate using a lot of different tools — Bluetooth, wireless, all those sorts of things. But for a tiny, power-constrained robot, we are forced to think about new modes of communication. This is a major step toward flying these robots in outdoor environments where we don’t have a well-tuned, state-of-the-art motion tracking system,” says Kevin Chen, who is the D. Reid Weedon, Jr. Assistant Professor in the Department of Electrical Engineering and Computer Science (EECS), the head of the Soft and Micro Robotics Laboratory in the Research Laboratory of Electronics (RLE), and the senior author of the paper.

Nanoparticles control light like road signs direct traffic

The particles control the flow of light like road signs control traffic on a busy road by manipulating the direction in which light can, or can't, travel.
Image Credit: Jamie Kidston / ANU

Physicists at The Australian National University (ANU) have developed tiny translucent slides capable of producing two very different images depending on the direction in which light travels through them.

As light passes through the slide, an image of Australia can be seen, but when you flip the slide and look again, an image of the Sydney Opera House is visible. The pair of images created is just one example of an untapped number of possibilities.

The ability to produce two distinctly different images is possible thanks to the ANU scientists' ability to control the direction in which light can and can't travel at the nanoscale. The development could pave the way for new light-based devices that could lead to faster, cheaper and more reliable Internet. It could also serve as the foundation for many of the technologies of tomorrow.

Developed in collaboration with colleagues from China, Germany and Singapore, the new technology uses nanoparticles, so small that about 12,000 of them can fit within a cross-section of a human hair. These tiny particles are arranged into unique patterns on the slides.

"The particles control the flow of light like road signs control traffic on a busy road by manipulating the direction in which light can, or can't, travel," project leader Dr Sergey Kruk said.

"Some particles allow light to flow from left to right only, others from right to left or the pathway might be blocked in either direction."

A rare discovery of long-term memory in wild frog-eating bats

A frog-eating bat approaches the ringtone and prepares to snatch up a baitfish snack.
Credit: Andrew Quitmeyer

New research has found that Frog-eating bats trained by researchers to associate a phone ringtone with a tasty treat were able to remember what they learned for up to four years in the wild, new research has found.

The study acquainted 49 bats with a series of ringtones that attracted their attention, and trained them to associate flying toward just one of the tones with a reward: a baitfish snack.

Between one and four years later, eight of those bats were recaptured and exposed again to the food-related ringtone. All of them flew toward the sound, and six flew all the way to the speaker and grabbed the food reward, meaning they expected to find food. Control bats without previous training on the sounds were comparatively unmoved by the exposure to the unfamiliar tones.

“I was surprised – I went into this thinking that at least a year would be a reasonable time for them to remember, given all the other things they need to know and given that long-term memory does have real costs. Four years strikes me as a long time to hold on to a sound that you might never hear again,” said lead author May Dixon, a postdoctoral scholar in evolution, ecology and organismal biology at The Ohio State University.

Dixon led this study at the Smithsonian Tropical Research Institute in Panama while she was a graduate student at the University of Texas at Austin.