Gut bacteria can alter the protective effects of a gene that wards off type 1 diabetes

Date:
August 30, 2017

Source:
Harvard Medical School

Summary:
A guardian gene that protects against type 1 diabetes and other autoimmune diseases exerts its pancreas-shielding effects by altering the gut microbiota. Experiments in mice born with the protective gene show that exposure to antibiotics during critical windows of development fuels risk for type 1 diabetes and leads to loss of genetic protection by altering the gut microbiota. Scientists say the findings underscore the importance of avoiding antibiotic use during late pregnancy and early infancy.

 

Diabetes concept (stock image). A new study found that despite harboring a powerful guardian gene, mice developed severe inflammation of the pancreas — a precursor to type 1 diabetes — after receiving antibiotics shortly after birth or if raised in a sterile environment.
Credit: © designer491 / Fotolia

 

 

Keeping the immune system in balance is no small feat. It must remain keenly alert to spot and disarm foreign invaders and smart enough to recognize the body’s own tissues and organs to spare them from a misdirected attack — a mistken response known as autoimmunity.

Some of the workhorses that keep the immune system in check are tiny proteins on the surface of cells encoded by a set of guardian genes — human leukocyte antigen (HLA) in humans and major histocompatibility complexes (MHC) in mice. Scientists have long known that certain common variants of the HLA/MHC genes protect against a range of autoimmune diseases, notably type 1 diabetes.

Yet how these genes and the tiny cell proteins they regulate yield their immune-modulating effects has remained shrouded in mystery. Now, a study in mice led by scientists at Harvard Medical School reveals that at least one of these genes has a protective influence that is powerfully shaped by the trillions of intestinal bacteria collectively known as the gut microbiota.

The team’s experiments, published Aug. 21 in the Proceedings of the National Academy of Sciences, show that despite harboring the powerful guardian gene, mice developed severe inflammation of the pancreas — a precursor to type 1 diabetes — after receiving antibiotics shortly after birth or if raised in a sterile environment.

The new findings demonstrate that gut bacteria are potent catalysts of autoimmunity and pancreatic cell function and that perturbations in the gut microbiota can precipitate diabetes. The results also open up avenues for immune-modulating therapies targeted at maintaining the delicate bacterial balance of the gut microbiota.

“We believe that our results not only offer a clue into a longstanding mystery but also raise the possibility that substances or environmental influences that alter the intestinal balance can modulate the effects of a powerfully protective gene and shape disease risk,” said Diane Mathis, who led the study together with Christophe Benoist, both professors in the Department of Microbiology and Immunobiology at Harvard Medical School.

The researchers caution that there are important physiological differences between mice and humans and emphasize that further studies are needed to elucidate precisely how gut bacteria affect gene activity and the risk for an autoimmune attack on the pancreas.

However, the scientists say their results highlight the role of the gut in proper immune function and point to the existence of a critical window in the proper development of the gut microbiome — a time during which the intestines get populated with a variety of bacteria.

“Our findings need to be borne out in further experiments,” Mathis said. “However, our results powerfully illustrate the notion that early antibiotic exposure can modulate disease risk and that avoiding or at least minimizing antibiotic treatment in infants and pregnant women during critical periods of development may be a good idea.”

Type 1 diabetes, a disorder estimated to affect more than 1.2 million Americans, is marked by dysfunction of the insulin-producing cells of the pancreas. The condition leads to a dangerous buildup of sugar in the body that, over time, can take a serious toll on the heart, kidneys, eyes and brain. Unlike the far more common type 2 diabetes, which develops as a result of excessive weight, obesity and diet in mostly middle-aged and older adults, type 1 diabetes tends to strike younger adults and children.

In the study, researchers worked with mice bred to spontaneously develop diabetes, the classic animal model for studying the disease. However, this particular group was also bred to carry a protective gene variant shown in earlier studies to ward off type 1 diabetes despite the animals’ heavy predisposition to the disease.

When treated with antibiotics in the first six weeks of life, mice went on to develop pancreatic inflammation, a precursor to type 1 diabetes, despite carrying the guardian gene. Treatment with antibiotics later in life — between six and 10 weeks after birth — did not lead to loss of protection against diabetes. The observation suggests a period during which the newborn gut is seeded by various germs, the researchers say. Interfering with that process by administering antibiotics appears to disrupt the balance of the gut microbiota, which in turn leads to loss of genetic protection, the researchers added.

Interestingly, mice whose protective gene was passed on by the father went on to develop diabetes. Mice that inherited a copy of the guardian gene from their mother, however, were resistant to diabetes. The observation highlights the critical protective role of exposing a newborn to the mother’s microbiota, which is passed on during birth.

Mice whose mothers had been given antibiotics in the 10 days before giving birth lost their genetic protection, the researchers found, and went on to develop pancreatic inflammation. Mice born with the protective gene but raised in sterile cages and deprived of bacterial exposure during early development never acquired gut microbial balance and disease protection. These animals developed severe pancreatic inflammation typically seen in diabetic mice. This observation, the researchers say, further underscores the importance of early environmental exposures to a variety of germs in the proper development of the immune system. The researchers note that the finding is also consistent with the so-called hygiene hypothesis, which posits that the declining number of childhood infections and lack of sufficient germ exposure during early childhood may fuel a person’s lifetime risk for allergic and autoimmune diseases. That link, however, the researchers caution, has yet to be proven.

In a final set of experiments, the team performed fecal transplants in diabetes-prone mice without the protective gene using fecal matter obtained from mice that carried the guardian gene. Following fecal transplantation, the diabetes-prone mice exhibited dramatically reduced pancreatic cell inflammation and did not develop diabetes — a finding that further affirms the role of gut bacteria as a powerful modulator of disease.

Co-investigators include Michael Silverman, Lindsay Kua, Alessandro Tanca, Mauro Pala, Antonio Palomba, Ceylan Tanes, Kyle Bittinger, and Sergio Uzzau.

The work was supported by The JPB Foundation, a gift from the Howalt family, by a Pediatric Infectious Disease Society Fellowship Award, the Juvenile Diabetes Research Foundation fellowship 10-2013-105, a Child Health Research Center K12 Award, the National Institutes of Health grant K08AI114970, and a National Science Foundation Fellowship DGE1144152.

Story Source:

Materials provided by Harvard Medical SchoolNote: Content may be edited for style and length.


Journal Reference:

  1. Michael Silverman, Lindsay Kua, Alessandro Tanca, Mauro Pala, Antonio Palomba, Ceylan Tanes, Kyle Bittinger, Sergio Uzzau, Christophe Benoist, Diane Mathis. Protective major histocompatibility complex allele prevents type 1 diabetes by shaping the intestinal microbiota early in ontogenyProceedings of the National Academy of Sciences, 2017; 201712280 DOI: 10.1073/pnas.1712280114

 

Source: Harvard Medical School. “Protecting the guardians: Gut bacteria can alter the protective effects of a gene that wards off type 1 diabetes.” ScienceDaily. ScienceDaily, 30 August 2017. <www.sciencedaily.com/releases/2017/08/170830155511.htm>.

Tumor-targeting immune cells appeared to spontaneously reactivate after biopsy of recurrent, subcutaneous lesion

Date:
August 28, 2017

Source:
Massachusetts General Hospital

Summary:
Medical researchers report a remarkable treatment response in a patient participating in a clinical trial of a novel immune-system-based cancer therapy.

 

MRI of the brain. (stock image)
Credit: © ?????? ??????? / Fotolia

 

 

In a letter to the New England Journal of Medicine, a Massachusetts General Hospital (MGH) research team reports a remarkable treatment response in a patient participating in a clinical trial of a novel immune-system-based cancer therapy. Treatment with an investigational CAR T-cell therapy induced complete remission of a brain metastasis of the difficult-to-treat tumor diffuse large-B-cell lymphoma (DLBCL), which had become resistant to chemotherapy — the first report of a response to CAR T-cells in a central nervous system lymphoma.

In addition, when a subcutaneous tumor began to recur two months after CAR T-cell therapy and a surgical biopsy was performed, the CAR T-cells spontaneously re-expanded and the tumor again went into remission, and phenomenon that had not previously been reported. While the patient eventually relapsed and died more than a year after CAR T-cell therapy, the brain tumor never recurred.

“Brain involvement in DLBCL carries a grave prognosis, and the ability to induce a complete and durable response with conventional therapies is rare,” explains Jeremy Abramson, MD, of the MGH Cancer Center , lead author of the letter in the Aug. 24 NEJM. “In addition, all available CAR T-cell trials have excluded patients with central nervous system involvement. This result has implications not only for secondary DLBCL like this case but also for primary central nervous system lymphoma, for which treatment options are similarly limited after relapse and few patents are cured.

Chimeric antigen receptor (CAR) T-cell therapies utilize a patient’s own T cells that have been genetically engineered to bind to a specific antigen on target cancer cells. This clinical trial sponsored by Juno Therapeutics is testing JCAR017, which targets the CD19 protein expressed on most B-cell leukemias and lymphomas. The most common type of non-Hodgkin lymphoma in adults, DLBCL is an aggressive cancer that can develop in many types of tissue.

This patient was a 68-year-old woman with DLBCL that had not responded either to conventional chemotherapies or to a stem-cell transplant, a situation that usually leads to a life expectancy of less than six months. After enrolling in the study — a phase 1 trial designed to investigate the safety and antitumor activity of JCAR017 — -she was found to have new lesion in the right temporal lobe of her brain.

One month after the study treatment — which involves chemotherapy followed by intravenous infusion of JCAR017 — follow-up imaging showed complete remission of the brain lesion. The subcutaneous lesion that recurred two months later disappeared after the biopsy with no further treatment. Blood testing showed an expansion in the numbers of CD19-targeted CAR T-cells that coincided with the tumor’s regression. While re-expansion of CAR T-cells has been reported in response to other immunotherapy drugs, this is the first report of such a response to a biopsy.

“Typically the drugs we use to fight cancer and other diseases wear off over time,” Abramson explains. “This spontaneous re-expansion after biopsy highlights this therapy as something entirely different, a ‘living drug’ that can re-expand and proliferate in response to biologic stimuli.” He and his co-authors note that discovering the mechanisms behind the reactivation of CAR T-cells could further augment their efficacy.

Story Source:

Materials provided by Massachusetts General HospitalNote: Content may be edited for style and length.


Journal Reference:

  1. Jeremy S. Abramson, Brianne McGree, Sarah Noyes, Sean Plummer, Curtis Wong, Yi-Bin Chen, Edwin Palmer, Tina Albertson, Judith A. Ferry, Isabel C. Arrillaga-Romany. Anti-CD19 CAR T Cells in CNS Diffuse Large-B-Cell LymphomaNew England Journal of Medicine, 2017; 377 (8): 783 DOI: 10.1056/NEJMc1704610

 

Source: Massachusetts General Hospital. “Complete remission of brain metastasis of difficult-to-treat tumor: Tumor-targeting immune cells appeared to spontaneously reactivate after biopsy of recurrent, subcutaneous lesion.” ScienceDaily. ScienceDaily, 28 August 2017. <www.sciencedaily.com/releases/2017/08/170828140742.htm>.

Date:
August 28, 2017

Source:
European Society of Cardiology

Summary:
A 16-year study in more than 280,000 patients has suggested that air temperature is an external trigger for heart attack. The average number of heart attacks per day was significantly higher during seasons with colder outdoor temperatures as compared to warmer.

 

Heart attacks occur more frequently in winter.
Credit: © ibreakstock / Fotolia

 

 

A 16 year study in more than 280,000 patients has suggested that air temperature is an external trigger for heart attack. The findings are presented today at ESC Congress.

“There is seasonal variation in the occurrence of heart attack, with incidence declining in summer and peaking in winter,” said first author Dr Moman A. Mohammad, from the Department of Cardiology at Lund University, Skane University Hospital, Lund, Sweden. “It is unclear whether this is due to colder temperatures or behavioural changes.”

This nationwide, 16 year, observational study led by Prof David Erlinge from Lund University, is the largest to investigate the association between heart attack incidence and weather conditions such as air temperature, sunshine duration, precipitation, and air pressure.

Using the Swedish myocardial infarction registry (SWEDEHEART), all consecutive heart attacks treated at a coronary care unit between 1 January 1998 and 31 December 2013 were included in the study. The investigators studied the specific weather conditions during which heart attacks occurred using local meteorological data from hundreds of weather stations in the Swedish Meteorological and Hydrological Institute (SMHI).

The average daily minimum temperature was calculated for the entire country as well as the six healthcare regions in Sweden and stratified as <0 °C, 1-10 °C and >10 °C. The relationship between the average number of heart attacks per day and the average minimum air temperature was evaluated.

During the study period, a total of 280,873 heart attacks occurred of which meteorological data were available for 99%. The average number of heart attacks per day was significantly higher during colder temperatures as compared to warmer. The results were consistent across healthcare regions.

On a day-to-day basis, this translated into four more heart attacks in Sweden when the average daily temperature was less than 0 °C as compared to when it was above 10°C. Furthermore, the occurrence of heart attacks was increased with higher wind velocities, limited sunshine duration and higher air humidity. Consistent results were observed in ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction.

The investigators analysed the relationship between heart attack incidence and weather conditions in subgroups including the elderly, those with hypertension, diabetes mellitus or previous heart attacks, and patients taking various medications. The link between heart attack incidence and weather conditions was stable across subgroups.

Dr Mohammad said: “Our results consistently showed a higher occurrence of heart attacks in sub-zero temperatures. The findings were the same across a large range of patient subgroups, and at national as well as regional levels, suggesting that air temperature is a trigger for heart attack.”

The body responds to cold by constricting superficial blood vessels, which decreases thermal conduction in the skin and subsequently increases arterial blood pressure. Other responses are shivering and increased heart rate, which raise the metabolic rate and in turn increase body temperature.

“In the majority of healthy people these mechanisms are well tolerated,” said Dr Mohammad. “But in people with atherosclerotic plaques in their coronary arteries they may trigger a heart attack.”

As this was an observational study, Dr Mohammad said there were other factors that may have contributed to the results. He said: “Respiratory tract infections and influenza are known risk factors for heart attack that have a clear seasonal variation. In addition, seasonal-dependent behaviours such as reduced physical activity and dietary changes could play a role in the increased occurrence of heart attack during colder weather.”

Story Source:

Materials provided by European Society of CardiologyNote: Content may be edited for style and length.

 

Source: European Society of Cardiology. “Air temperature is external trigger for heart attack.” ScienceDaily. ScienceDaily, 28 August 2017. <www.sciencedaily.com/releases/2017/08/170828093807.htm>.

Although we’re on vacation now, when our friend and colleague, James Farley, vTv Therapeutics LLC’s Director of Data Management and Programming, sent these spectacular eclipse photos, we had to interrupt our R&R to share James’ extraordinary photos with you, our readers.

James took a PTO day last Monday and drove his whole family to Burgess Falls State Nature Area, Sparta, Tennessee! They had clear skies there and were almost in the center of the Path of Totality. James says it was the most thrilling, epic experience! The following spectacular photos are the Totality, Diamond Ring Effect and an Eclipse Composite of the full progression.

 

Solar Eclipse 2017 – Eclipse Progression Composite

Copyright 2017 Advanced Fine Art.

 

Solar Eclipse 2017 – Totality

Copyright 2017 Advanced Fine Art.

 

Solar Eclipse 2017 – Diamond Ring Effect

Copyright 2017 Advanced Fine Art.

Date:
August 24, 2017

Source:
University of New South Wales

Summary:
Scientists have discovered the purpose of a famous 3,700-year old Babylonian clay tablet, revealing it is the world’s oldest and most accurate trigonometric table, possibly used by ancient mathematical scribes to calculate how to construct palaces and temples and build canals. The new research shows the Babylonians beat the Greeks to the invention of trigonometry — the study of triangles — by more than 1,000 years.

 

The 3,700-year-old Babylonian tablet Plimpton 322 at the Rare Book and Manuscript Library at Columbia University in New York.
Credit: UNSW/Andrew Kelly

 

 

UNSW Sydney scientists have discovered the purpose of a famous 3700-year old Babylonian clay tablet, revealing it is the world’s oldest and most accurate trigonometric table, possibly used by ancient mathematical scribes to calculate how to construct palaces and temples and build canals.

The new research shows the Babylonians, not the Greeks, were the first to study trigonometry — the study of triangles — and reveals an ancient mathematical sophistication that had been hidden until now.

Known as Plimpton 322, the small tablet was discovered in the early 1900s in what is now southern Iraq by archaeologist, academic, diplomat and antiquities dealer Edgar Banks, the person on whom the fictional character Indiana Jones was based.

It has four columns and 15 rows of numbers written on it in the cuneiform script of the time using a base 60, or sexagesimal, system.

The UNSW Science research provides an alternative to the widely-accepted view that the tablet was a teacher’s aid for checking students’ solutions of quadratic problems.

“The huge mystery, until now, was its purpose — why the ancient scribes carried out the complex task of generating and sorting the numbers on the tablet.

“Our research reveals that Plimpton 322 describes the shapes of right-angle triangles using a novel kind of trigonometry based on ratios, not angles and circles. It is a fascinating mathematical work that demonstrates undoubted genius.

The new study by Dr Mansfield and UNSW Associate Professor Norman Wildberger is published in Historia Mathematica, the official journal of the International Commission on the History of Mathematics.

A trigonometric table allows you to use one known ratio of the sides of a right-angle triangle to determine the other two unknown ratios.

The Greek astronomer Hipparchus, who lived about 120 years BC, has long been regarded as the father of trigonometry, with his “table of chords” on a circle considered the oldest trigonometric table.

“Plimpton 322 predates Hipparchus by more than 1000 years,” says Dr Wildberger. “It opens up new possibilities not just for modern mathematics research, but also for mathematics education. With Plimpton 322 we see a simpler, more accurate trigonometry that has clear advantages over our own.”

“A treasure-trove of Babylonian tablets exists, but only a fraction of them have been studied yet. The mathematical world is only waking up to the fact that this ancient but very sophisticated mathematical culture has much to teach us.”

Dr Mansfield read about Plimpton 322 by chance when preparing material for first year mathematics students at UNSW. He and Dr Wildberger decided to study Babylonian mathematics and examine the different historical interpretations of the tablet’s meaning after realizing that it had parallels with the rational trigonometry of Dr Wildberger’s book Divine Proportions: Rational Trigonometry to Universal Geometry.

The 15 rows on the tablet describe a sequence of 15 right-angle triangles, which are steadily decreasing in inclination.

The left-hand edge of the tablet is broken and the UNSW researchers build on previous research to present new mathematical evidence that there were originally 6 columns and that the tablet was meant to be completed with 38 rows.

They also demonstrate how the ancient scribes, who used a base 60 numerical arithmetic similar to our time clock, rather than the base 10 number system we use, could have generated the numbers on the tablet using their mathematical techniques.

The UNSW Science mathematicians also provide evidence that discounts the widely-accepted view that the tablet was simply a teacher’s aid for checking students’ solutions of quadratic problems.

“Plimpton 322 was a powerful tool that could have been used for surveying fields or making architectural calculations to build palaces, temples or step pyramids,” says Dr Mansfield.

The tablet, which is thought to have come from the ancient Sumerian city of Larsa, has been dated to between 1822 and 1762 BC. It is now in the Rare Book and Manuscript Library at Columbia University in New York.

A Pythagorean triple consists of three, positive whole numbers a, b and c such that a2 + b2 = c2. The integers 3, 4 and 5 are a well-known example of a Pythagorean triple, but the values on Plimpton 322 are often considerably larger with, for example, the first row referencing the triple 119, 120 and 169.

The name is derived from Pythagoras’ theorem of right-angle triangles which states that the square of the hypotenuse (the diagonal side opposite the right angle) is the sum of the squares of the other two sides.

Story Source:

Materials provided by University of New South WalesNote: Content may be edited for style and length.


Journal Reference:

  1. Daniel F. Mansfield , N.J. Wildberger. Plimpton 322 is Babylonian exact sexagesimal trigonometryHistoria Mathematica, August 2017 DOI: 10.1016/j.hm.2017.08.001

 

Source: University of New South Wales. “Mathematical mystery of ancient Babylonian clay tablet solved.” ScienceDaily. ScienceDaily, 24 August 2017. <www.sciencedaily.com/releases/2017/08/170824141250.htm>.

Date:
August 23, 2017

Source:
University of Manchester

Summary:
Scientists have now demonstrated that storing data with a class of molecules known as single-molecule magnets is more feasible than previously thought.

 

The potential for molecular data storage is huge. (stock image)
Credit: © denisismagilov / Fotolia

 

 

From smartphones to supercomputers, the growing need for smaller and more energy efficient devices has made higher density data storage one of the most important technological quests.

Now scientists at the University of Manchester have proved that storing data with a class of molecules known as single-molecule magnets is more feasible than previously thought.

The research, led by Dr David Mills and Dr Nicholas Chilton, from the School of Chemistry, is being published in Nature. It shows that magnetic hysteresis, a memory effect that is a prerequisite of any data storage, is possible in individual molecules at -213 °C. This is extremely close to the temperature of liquid nitrogen (-196 °C).

The result means that data storage with single molecules could become a reality because the data servers could be cooled using relatively cheap liquid nitrogen at -196°C instead of far more expensive liquid helium (-269 °C). The research provides proof-of-concept that such technologies could be achievable in the near future.

The potential for molecular data storage is huge. To put it into a consumer context, molecular technologies could store more than 200 terabits of data per square inch — that’s 25,000 GB of information stored in something approximately the size of a 50p coin, compared to Apple’s latest iPhone 7 with a maximum storage of 256 GB.

Single-molecule magnets display a magnetic memory effect that is a requirement of any data storage and molecules containing lanthanide atoms have exhibited this phenomenon at the highest temperatures to date. Lanthanides are rare earth metals used in all forms of everyday electronic devices such as smartphones, tablets and laptops. The team achieved their results using the lanthanide element dysprosium.

Dr Chilton says: ‘This is very exciting as magnetic hysteresis in single molecules implies the ability for binary data storage. Using single molecules for data storage could theoretically give 100 times higher data density than current technologies. Here we are approaching the temperature of liquid nitrogen, which would mean data storage in single molecules becomes much more viable from an economic point of view.’

The practical applications of molecular-level data storage could lead to much smaller hard drives that require less energy, meaning data centres across the globe could become a lot more energy efficient.

For example, Google currently has 15 data centres around the world. They process an average of 40 million searches per second, resulting in 3.5 billion searches per day and 1.2 trillion searches per year. To deal with all that data, in July last year, it was reported that Google had approximately 2.5 million servers in each data centre and that number was likely to rise.

Some reports say the energy consumed at such centres could account for as much as 2 per cent of the world’s total greenhouse gas emissions. This means any improvement in data storage and energy efficiency could also have huge benefits for the environment as well as vastly increasing the amount of information that can be stored.

Dr Mills adds: ‘This advance eclipses the previous record which stood at -259 °C, and took almost 20 years of research effort to reach. We are now focused on the preparation of new molecules inspired by the design in this paper. Our aim is to achieve even higher operating temperatures in the future, ideally functioning above liquid nitrogen temperatures.’

Story Source:

Materials provided by University of ManchesterNote: Content may be edited for style and length.


Journal Reference:

  1. Conrad A. P. Goodwin, Fabrizio Ortu, Daniel Reta, Nicholas F. Chilton, David P. Mills. Molecular magnetic hysteresis at 60 kelvin in dysprosoceniumNature, 2017; 548 (7668): 439 DOI: 10.1038/nature23447

 

Source: University of Manchester. “Major leap towards data storage at the molecular level.” ScienceDaily. ScienceDaily, 23 August 2017. <www.sciencedaily.com/releases/2017/08/170823131241.htm>.

Date:
August 22, 2017

Source:
American Chemical Society

Summary:
Photosynthesis provides energy for the vast majority of life on Earth. But chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient. To enable humans to capture more of the sun’s energy, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

 

Artist’s rendering of bioreactor (left) loaded with bacteria decorated with cadmium sulfide, light-absorbing nanocrystals (middle) to convert light, water and carbon dioxide into useful chemicals (right).
Credit: Kelsey K. Sakimoto

 

 

Photosynthesis provides energy for the vast majority of life on Earth. But chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient. To enable humans to capture more of the sun’s energy than natural photosynthesis can, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

The researchers are presenting their work today at the 254th National Meeting & Exposition of the American Chemical Society (ACS).

“Rather than rely on inefficient chlorophyll to harvest sunlight, I’ve taught bacteria how to grow and cover their bodies with tiny semiconductor nanocrystals,” says Kelsey K. Sakimoto, Ph.D., who carried out the research in the lab of Peidong Yang, Ph.D. “These nanocrystals are much more efficient than chlorophyll and can be grown at a fraction of the cost of manufactured solar panels.”

Humans increasingly are looking to find alternatives to fossil fuels as sources of energy and feedstocks for chemical production. Many scientists have worked to create artificial photosynthetic systems to generate renewable energy and simple organic chemicals using sunlight. Progress has been made, but the systems are not efficient enough for commercial production of fuels and feedstocks.

Research in Yang’s lab at the University of California, Berkeley, where Sakimoto earned his Ph.D., focuses on harnessing inorganic semiconductors that can capture sunlight to organisms such as bacteria that can then use the energy to produce useful chemicals from carbon dioxide and water. “The thrust of research in my lab is to essentially ‘supercharge’ nonphotosynthetic bacteria by providing them energy in the form of electrons from inorganic semiconductors, like cadmium sulfide, that are efficient light absorbers,” Yang says. “We are now looking for more benign light absorbers than cadmium sulfide to provide bacteria with energy from light.”

Sakimoto worked with a naturally occurring, nonphotosynthetic bacterium, Moorella thermoacetica, which, as part of its normal respiration, produces acetic acid from carbon dioxide (CO2). Acetic acid is a versatile chemical that can be readily upgraded to a number of fuels, polymers, pharmaceuticals and commodity chemicals through complementary, genetically engineered bacteria.

When Sakimoto fed cadmium and the amino acid cysteine, which contains a sulfur atom, to the bacteria, they synthesized cadmium sulfide (CdS) nanoparticles, which function as solar panels on their surfaces. The hybrid organism, M. thermoacetica-CdS, produces acetic acid from CO2, water and light. “Once covered with these tiny solar panels, the bacteria can synthesize food, fuels and plastics, all using solar energy,” Sakimoto says. “These bacteria outperform natural photosynthesis.”

The bacteria operate at an efficiency of more than 80 percent, and the process is self-replicating and self-regenerating, making this a zero-waste technology. “Synthetic biology and the ability to expand the product scope of CO2 reduction will be crucial to poising this technology as a replacement, or one of many replacements, for the petrochemical industry,” Sakimoto says.

So, do the inorganic-biological hybrids have commercial potential? “I sure hope so!” he says. “Many current systems in artificial photosynthesis require solid electrodes, which is a huge cost. Our algal biofuels are much more attractive, as the whole CO2-to-chemical apparatus is self-contained and only requires a big vat out in the sun.” But he points out that the system still requires some tweaking to tune both the semiconductor and the bacteria. He also suggests that it is possible that the hybrid bacteria he created may have some naturally occurring analog. “A future direction, if this phenomenon exists in nature, would be to bioprospect for these organisms and put them to use,” he says.

A video on the research is available at https://www.youtube.com/watch?v=opl5CnDA_2c&feature=youtu.be

Story Source:

Materials provided by American Chemical SocietyNote: Content may be edited for style and length.

 

Source: American Chemical Society. “Cyborg bacteria outperform plants when turning sunlight into useful compounds.” ScienceDaily. ScienceDaily, 22 August 2017. <www.sciencedaily.com/releases/2017/08/170822092234.htm>.

Researchers discover a new molecule, ‘Singheart,’ that may hold the key to triggering the regeneration and repair of damaged heart cells

Date:
August 21, 2017

Source:
National University Health System

Summary:
New research has discovered a potential means to trigger damaged heart cells to self-heal. The discovery could lead to groundbreaking forms of treatment for heart diseases. For the first time, researchers have identified a long non-coding ribonucleic acid (ncRNA) that regulates genes controlling the ability of heart cells to undergo repair or regeneration. This novel RNA, called ‘Singheart,’ may be targeted for treating heart failure in the future.

 

A mouse heart cell with 2 nuclei (blue) and Singheart RNA labelled by red fluorescent dyes.
Credit: A*STAR’s Genome Institute of Singapore

 

 

New research has discovered a potential means to trigger damaged heart cells to self-heal. The discovery could lead to groundbreaking forms of treatment for heart diseases. For the first time, researchers have identified a long non-coding ribonucleic acid (ncRNA) that regulates genes controlling the ability of heart cells to undergo repair or regeneration. This novel RNA, which researchers have named “Singheart,” may be targeted for treating heart failure in the future. The discovery was made jointly by A*STAR’s Genome Institute of Singapore (GIS) and the National University Health System (NUHS), and is now published in Nature Communications.

Unlike most other cells in the human body, heart cells do not have the ability to self-repair or regenerate effectively, making heart attack and heart failure severe and debilitating. Cardiovascular disease (CVD) is the leading cause of death worldwide, with an estimated 17.7 million people dying from CVD in 2015. CVD also accounted for close to 30% of all deaths in Singapore in 2015.

In this project, the researchers used single cell technology to explore gene expression patterns in healthy and diseased hearts. The team discovered that a unique subpopulation of heart cells in diseased hearts activate gene programmes related to heart cell division, uncovering the gene expression heterogeneity of diseased heart cells for the first time. In addition, they also found the “brakes” that prevent heart cells from dividing and thus self-healing. Targeting these “brakes” could help trigger the repair and regeneration of heart cells.

“There has always been a suspicion that the heart holds the key to its own healing, regenerative and repair capability. But that ability seems to become blocked as soon as the heart is past its developmental stage. Our findings point to this potential block that when lifted, may allow the heart to heal itself,” explained A/Prof Roger Foo, the study’s lead author, who is Principal Investigator at both GIS and NUHS’ Cardiovascular Research Institute (CVRI) and Senior Consultant at the National University Heart Centre, Singapore (NUHCS).

“In contrast to a skin wound where the scab falls off and new skin grows over, the heart lacks such a capability to self-heal, and suffers a permanent scar instead. If the heart can be motivated to heal like the skin, consequences of a heart attack would be banished forever,” added A/Prof Foo.

The study was driven by first author and former Senior Research Fellow at the GIS, Dr Kelvin See, who is currently a Postdoctoral Researcher and Mack Technology Fellow at University of Pennsylvania.

“This new research is a significant step towards unlocking the heart’s full regenerative potential, and may eventually translate to more effective treatment for heart diseases. Heart disease is the top disease burden in Singapore and strong funding remains urgently needed to enable similar groundbreaking discoveries,” said Prof Mark Richards, Director of CVRI.

Executive Director of GIS, Prof Ng Huck Hui added, “This cross-institutional research effort serves as a strong foundation for future heart studies. More importantly, uncovering barriers that stand in the way of heart cells’ self-healing process brings us another step closer to finding a cure for one of the world’s biggest killers.”

Story Source:

Materials provided by National University Health SystemNote: Content may be edited for style and length.


Journal Reference:

  1. Kelvin See, Wilson L. W. Tan, Eng How Lim, Zenia Tiang, Li Ting Lee, Peter Y. Q. Li, Tuan D. A. Luu, Matthew Ackers-Johnson, Roger S. Foo. Single cardiomyocyte nuclear transcriptomes reveal a lincRNA-regulated de-differentiation and cell cycle stress-response in vivoNature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-00319-8

 

Source: National University Health System. “Repairing damaged hearts with self-healing heart cells: Researchers discover a new molecule, ‘Singheart,’ that may hold the key to triggering the regeneration and repair of damaged heart cells.” ScienceDaily. ScienceDaily, 21 August 2017. <www.sciencedaily.com/releases/2017/08/170821094253.htm>.

Scientists sequence a whole genome on a Welsh mountainside to identify a plant species within hours

Date:
August 21, 2017

Source:
Royal Botanic Gardens Kew

Summary:
A new article reveals the opportunities for portable, real-time DNA sequencing in plant identification and naming. Using a handheld DNA sequencing device they conducted the first genomic plant sequencing in the field at a fraction of the speed of traditional methods, offering exciting possibilities to conservationists and scientists the world over.

 

The field identification of two different white flowers Arabidopsis thaliana and Arabidopsis lyrata ssp. petraea was achieved by sequencing random parts of the plants’ genomes and comparing their new data to a database of reference genome sequences.
Credit: Alex Papadopolous

 

 

In a paper published today in Scientific Reports(Nature Publishing Group), researchers at the Royal Botanic Gardens, Kew, detail for the first time the opportunities for plant sciences that are now available with portable, real-time DNA sequencing.

Kew scientist and co-author of the paper Joe Parker says; “This research proves that we can now rapidly read the DNA sequence of an organism to identify it with minimum equipment. Rapidly reading DNA anywhere, at will, should become a routine step in many research fields. Despite hundreds of years of taxonomic research, it is still not always easy to work out which species a plant belongs to just by looking at it. Few people could correctly identify all the species in their own gardens.”

Over the last forty years, DNA sequencing has revolutionised the scientific world but has remained laboratory-bound. Using current methods, a complete experiment to identify a species, from fieldwork to result, could easily take a scientist months to complete. Species identification is, by nature, a largely a field-based area of pursuit, thereby limiting the pace of discovery and decision making that can depend upon it. Using new technology to identify species quickly and on-site is critical for scientific research, the conservation of biodiversity and in the fight against species crime.

In this new study, Kew scientists used the portable DNA sequencer, the MinION from Oxford Nanopore Technologies, to analyse plant species in Snowdonia National Park. This was the first time genomic sequencing of plants has been performed in the field.

This technology, commercially launched in 2015, has since been used in Antarctica, in remote regions affected by disease, and on the International Space Station.

One of the successes illustrated in the paper is the field identification of two innocuous white flowers, Arabidopsis thaliana and Arabidopsis lyrata ssp. petraea. This was achieved by sequencing random parts of the plants’ genomes, avoiding the tricky and time consuming process of targeting specific pieces of DNA which is the more traditional approach for identifying species with DNA.

The researchers compared their new data to a freely available database of reference genome sequences to make their identification. Crucially, replicating their experiment in Kew’s Jodrell Laboratory with other DNA sequencing methods allowed them to devise sophisticated statistics to understand the useful properties of this new kind of data for the first time.

Alexander Papadopulos, Kew scientist and co-author on the paper, says; “Accurate species identification is essential for evolutionary and ecological research, in the fight against wildlife crime and for monitoring rare and threatened species. Identifying species correctly based on what they look like can be really tricky and needs expertise to be done well. This is especially true for plants when they aren’t in flower or when they have been processed into a product. Our experiments show that by sequencing random pieces of the genome in the field it’s possible to get very accurate species identification within a few hours of collecting a specimen. More traditional methods need a lot of lab equipment and have often only provided enough information to identify a sample to the genus level.”

There are other useful properties of their data too. This field sequenced data can be used to assemble a whole genome sequence, act as a reference database for the species and help understand evolutionary relationships. Currently, the team is exploring the feasibility of rapidly generating a reference sequence database from the incredibly diverse collection of plants help in Kew’s living collection and herbarium as well as applications for monitoring plant health.

Story Source:

Materials provided by Royal Botanic Gardens KewNote: Content may be edited for style and length.


Journal Reference:

  1. Joe Parker, Andrew J. Helmstetter, Dion Devey, Tim Wilkinson, Alexander S. T. Papadopulos. Field-based species identification of closely-related plants using real-time nanopore sequencingScientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-08461-5

 

Source: Royal Botanic Gardens Kew. “Into the wild for plant genetics: Scientists sequence a whole genome on a Welsh mountainside to identify a plant species within hours.” ScienceDaily. ScienceDaily, 21 August 2017. <www.sciencedaily.com/releases/2017/08/170821085646.htm>.

Date:
August 17, 2017

Source:
University of Hawaii at Manoa

Summary:
Oceanographers report completing the largest single-site microbiome gene catalog constructed to date. With this new information, the team discovered nutrient limitation is a central driver in the evolution of ocean microbe genomes.

 

A rosette sampler captures water at specified depths at Station ALOHA.
Credit: Tara Clemente, UH M?noa

 

 

Microbes dominate the planet, especially the ocean, and help support the entire marine food web. In a recent report published in Nature Microbiology, University of Hawai’i at M?noa (UHM) oceanography professor Ed DeLong and his team report the largest single-site microbiome gene catalog constructed to date. With this new information, the team discovered nutrient limitation is a central driver in the evolution of ocean microbe genomes.

As a group, marine microbes are extremely diverse and versatile with respect to their metabolic capabilities. All of this variability is encoded in their genes. Some marine microorganisms have genetic instructions that allow them to use the energy derived from sunlight to turn carbon dioxide into organic matter. Others use organic matter as a carbon and energy source and produce carbon dioxide as a respiration end-product. Other, more exotic pathways have also been discovered.

“But how do we characterize all these diverse traits and functions in virtually invisible organisms, whose numbers approach a million cells per teaspoon of seawater?” asked DeLong, senior author on the paper. “This newly constructed, comprehensive gene catalog of microbes inhabiting the ocean waters north of the Hawaiian Islands addresses this challenge.”

Water samples were collected over two years, and modern genome sequencing technologies were used to decode the genes and genomes of the most abundant microbial species in the upper 3,000 feet of water at the Hawai’i Ocean Time-series (HOT) Program open ocean field site, Station ALOHA.

Just below the depth of sunlit layer, the team observed a sharp transition in the microbial communities present. They reported that the fundamental building blocks of microbes, their genomes and proteins, changed drastically between depths of about 250-650 feet.

“In surface waters, microbial genomes are much smaller, and their proteins contain less nitrogen — a logical adaptation in this nitrogen-starved environment,” said Daniel Mende, post-doctoral researcher at the UHM School of Ocean and Earth Science and Technology (SOEST) and lead author on the paper. “In deeper waters, between 400-650 feet, microbial genomes become much larger, and their proteins contain more nitrogen, in tandem with increasing nitrogen availability with depth.”

“These results suggest that the availability of nutrients in the environment may actually shape how microbial genomes and proteins evolve in the wild,” said DeLong. “Another surprising finding of the study is that the microbial ‘genomic transition zone’ observed occurs over a very narrow depth range, just beneath the sunlit layer. Below about 650 feet deep, the fundamental properties of microbial genomes and proteins are relatively constant, all the way down to the seafloor.”

In collaboration with a computer science group led by professor Bonnie Hurwitz at the University of Arizona, the new database is available to scientists worldwide who are seeking to describe the nature and function of microbes in the global oceans.

“These new data will provide an important tool for understanding the nature and function of the ocean’s microbiome today, as well as help predict its trajectory into the future,” said DeLong.


Story Source:

Materials provided by University of Hawaii at ManoaNote: Content may be edited for style and length.


Journal Reference:

  1. Daniel R. Mende, Jessica A. Bryant, Frank O. Aylward, John M. Eppley, Torben Nielsen, David M. Karl, Edward F. DeLong. Environmental drivers of a microbial genomic transition zone in the ocean’s interiorNature Microbiology, 2017; DOI: 10.1038/s41564-017-0008-3

 

Source: University of Hawaii at Manoa. “New gene catalog of ocean microbiome reveals surprises.” ScienceDaily. ScienceDaily, 17 August 2017. <www.sciencedaily.com/releases/2017/08/170817162014.htm>.

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