Scientists build working heart tissue using spinach leaves

Need more proof spinach is good for your heart? Scientists may have figured out a way to “hack” one of the toughest issues in repairing damaged organs. Researchers have used spinach leaves to provide a framework to grow new heart tissue.

“Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge,” the research team wrote in the new study. “By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications.”

In layman’s terms, the veins in a spinach leaf has provided a sort of template for human heart tissue.

While scientists were able to create human tissue with 3-D printing and other technologies already, organ tissue has presented a larger challenge. Namely, scientists’ are unable to create the delicate vascular network needed to support it, said graduate student Joshua Gershlak, lead author of the paper.

“Techniques can’t fabricate microvasculature the way that the body needs it,” Gershlak said in a video that the Worcester Polytechnic Institute research team released to share their work. “Without that microvasculature, you lose that oxygen transport. So as you build a bigger and bigger graft, say for like a heart attack on a human, you’re going to need something fairly large. So without that vascular network, you get a lot of tissue death.”

That’s where the spinach leaves come in.

According to Dr. Glenn Gaudette, who also worked on the research project, the scientists take the spinach leaves and use a detergent to remove all of the plant material while leaving the vascular structure intact.

Then, they seed the structure with human cells, he said. As the human cells grow into cardiac muscle, they can be stacked, and the veins can, in theory, be attached to existing veins in the heart, Gaudette said.

The heart tissue they’ve created on spinach leaves looks and acts like normal cardiac cells, Gershlak said.

“These data demonstrate the potential of decellularized plants as scaffolds for tissue engineering, which could ultimately provide a cost-efficient, ‘green’ technology for regenerating large volume vascularized tissue mass,” the researchers wrote.

The full study will be published in the May issue of the journal Biomaterials.

By Kyla Cathey, Earth.com staff writer

Plant fossil dates complex life back another 400 million years

Did relatively complex life on Earth begin hundreds of million years earlier than we thought? That’s what’s suggested by the discovery of a red algae-like plant fossil that, at 1.6 billion years old, is evidence of the earliest plant known.

The first single-cell organism is known to be a couple billion year older than this discovery, but the red algae plant fossil is evidence of a more complex form of life, known as eukaryotes. This form, which includes humans and other animals, plants and even fungi, are indicated by the presence of a cell with a nucleus and other structures in a membrane.

Before this finding, the earliest evidence of red algae was some 400 million years more recent.

Researchers from the Swedish Museum of Natural History made their find in India, in what would have been shallow water when the plant lived, and published their findings in PLOS Biology. They stressed that their identification of the fossil as red algae could not be conclusive.

“You cannot be 100 percent sure about material this ancient, as there is no DNA remaining, but the characters agree quite well with the morphology and structure of red algae,” the museum’s Professor Stefan Bengtsontold explained to BBC News.

In addition to the unanswered questions due to the lack of DNA, some scientist question whether red algae should even be called plant life or if it would more accurately fall into a class of its own.

Image Credit: Stefan Bengtson

By Earth.com Staff Writer David Searls

Source: PLOS Biology

Forests reduce greenhouse gases, but don’t overpromise

Forests are an important, as well as aesthetically pleasing, tool for mitigating the effects of climate change and meeting the goals of the Paris Agreement on Climate Change. But what can we realistically expect in terms of mitigation potential?

In a paper published in Nature Climate Change titled “Key role of forests in meeting climate targets but science needed for credible mitigation,” scientists voiced the challenge in assigning realistic metrics for forests toward hitting the Paris goal of restraining global temperature rise.

In an interview with Earth.com, study co-author Dr. Joanna House of the University of Bristol’s Cabot Institute said, “Our paper highlights the urgent need for better transparency in accounting for emissions from the Land Use Land Use Change and Forestry (LULUCF) sector.  It shows that you get very different answers for CO2 mitigation in the land sector depending on the methods used by countries to do their accounting.”

House added, “It was also somewhat eye opening to realize how different historical emissions estimates were when reported by countries to UNFCCC (United Nations Framework Convention on Climate Change) using IPCC (Intergovernmental Panel on Climate Change) Good Practice Guidance methods, compared to the independent scientific global estimates we rely on, summarized in the IPCC Assessment Reports.”

In other words, world governments tend to be more optimistic in their metrics assignments for forestry than the scientific community.

“Countries consider the land sector, primarily forests, to be really critical in climate mitigation up to 2030, providing a quarter of mitigation potential,” said House. “Given the issues around competition for land, but the many co-benefits of forestry (protected or enhanced biodiversity, flood and erosion control, rainfall recycling), this is a clear signal to prioritize sustainable forestry.”

House added in the Earth.com interview that world governments must refrain from overpromising.

“Forests play an important role, not least because of the co-benefits of biodiversity, rainfall recycling, and protection from flooding and erosion. However, our land resource is limited, so there is no getting away from the need to also switch to low carbon energy as many countries are doing with great success while their economies continue to flourish.”

After all, she noted, fossil fuels are responsible for 90 percent of greenhouse gas emissions.

By David Searls, Earth.com Staff Writer

Source: Nature Climate Change, Earth.com

Climate change plays havoc with nature’s clock in Greenland

In Greenland, nature’s clock has gone haywire. Some plants are sprouting or emerging from winter dormancy far earlier than they should. Others are showing up later than usual.

According to biologists and polar ecologists from the University of California, Davis, the early spring that is speeding up or short-circuiting plants’ biological clocks seems to be connected to Earth’s changing climate.

“Monthly Arctic-wide sea ice extent was a significant predictor of emergence timing in 10 of 14 species,” the new study found.

It’s not just affecting plants, but also the species that depend on them for food, the scientists said.

Caribou in Greenland head into the low Arctic at the same time each year, in early spring, to forage for food. They rely on new growth, which is more nutritious, for the vitamins and energy they need to birth healthy calves.

When they eat plants that have been green for longer, they’re not as healthy, the Davis researchers said. Fewer calves are born, and fewer calves survive to adulthood, they said.

The timing of plant growth and flower budding has disrupted nature’s clock in Greenland for dozens of species, said the Davis researchers, who have been studying plant growth in Greenland for 12 years now. They study plant growth enclosed plots near the Russell Glacier in western Greenland every spring.

Over the past several years, which have seen record high temperatures and rapid loss of sea ice in the Arctic, the researchers have documented plants emerging much earlier or later than usual. For example, one sedge species begins its spring growth nearly a month earlier than it did a decade ago, the scientists said.

“When we started studying this, I never would have imagined we’d be talking about a 26-day per decade rate of advance,” lead author Dr. Eric Post said in a press release. Post has studied the Arctic for more than 25 years. “That’s almost an entire growing season. That’s an eye-opening rate of change.”

Not every plant has been affected. One willow species still buds at about the same time each year, and a dwarf birch species has only shifted by a few days.

However, the shifting of nature’s clock for some species is a trend scientists can’t ignore.

“Think of it as going from something like a Picasso painting that blurs before your eyes and reorganizes into some kind of Dali landscape,” Post said. “You can see the pieces are still there, but the way they’re organized in relation to each other doesn’t look like what it used to be, and you wonder, ‘What am I looking at now and what does that mean for how it all works together?’”

The Davis researchers are working with colleagues to study how else warmer temperatures and ice loss may be affecting Arctic species.

The study was published in the journal Biology Letters. It was funded by the National Science Foundation and the National Geographic Committee for Research and Exploration.

By Kyla Cathey, Earth.com staff writer

How ancient people changed the face of the rainforest

Imagine: you’re deep within the Brazilian rainforest when you discover huge, geometric trenches. Some of the huge shapes – squares and circles – measure as large as a city block. The trenches themselves are up to 13 feet deep and as much as 12 yards wide. These earthworks are a reality, and archaeologists believe they were built by ancient people around 2,000 years ago. They also found broken ceramics near the entrance to the shapes, but are unsure why the materials were left there.

The discovery of the ancient geometric earthworks has unearthed a stunning realization: rainforest areas that were previously thought to be undisturbed by humans until 15th century explorers arrived from Europe were actually subject to manipulation by the ancient people who built these glyphs – as well as those who came before them.

“A lot of people have the idea that the Amazon forests are pristine forests, never touched by humans, and that’s obviously not the case,” said Jennifer Watling, an archaeologist the University of São Paulo, Brazil, told the New York Times.

Researchers have found evidence of sustainable farming practices carried out thousands of years before the trenches were constructed.

They did this by carefully examining the environmental history of two of the areas in the Amazon rain forest in which glyphs are located. By analyzing soil samples, scientists were able to put together a story of ancient vegetation, as well as burnings that took place to make openings in the forest. Researchers believe that ancient forest dwellers may have planted maize or squash.

Somewhat like methods now known as agroforestry, the ancient people of the Amazon took care not to burn or clear-cut large swaths of land. Instead, they used sustainable farming at its best. Watling says that the biodiversity that exists in the Amazon today is due to the practices that were started all those many years ago and continued by indigenous groups even today.


By Dawn Henderson, Earth.com Staff Writer

Roses are red and violets are blue – but why?

Roses are red and violets are blue, but have you every wondered why? We know why flowers have colors – it helps them attract bees and other pollinators. They also help humans attract mates, surprising them with a heartfelt bouquet (or at least averting disaster by picking up one as a last-minute gift). But how exactly do flowers develop such a variety of vibrant hues?

Scientists have, and that’s why the National Science Foundation (NSF) is funding research into the genetics behind flower colors and how those colors change over time.

Stacy Smith of the University of Colorado Boulder is one of the members of the research team. She says that flower color is due to the “biochemical composition of petal cells.”

What is the biochemical composition, though? According to scientists, it’s pigment compounds such as flavonoids, carotenoids, and betalains.

If your ears perk up because you’ve heard of the health benefits of flavonoids, you’re on the right track. These hue-inducing compounds also have “antioxidant and other medicinal properties, including anti-cancer, anti-bacterial, and anti-inflammatory activity,” according to NSF Program Director Simon Malcomber.

Changes in the chemistry of these pigment compounds create different flower colors. Much of Smith’s work has focused on the tomato family of plants – one that includes species that range from tomatoes and eggplants to, surprisingly, tobacco and even potatoes. Her team is focusing on studying the wild species of these plants because they have a wider range of colors than their domesticated counterparts.

They’re currently working to determine when and how red flowers appeared in the tomato family of plants. In a species of nearly 2,800 plants, the tomato family only features 34 that have red flowers.

“With such a small number, we can take samples of every one of these species to find out whether it represents an independent origin, and to determine the biochemistry of how it makes red flowers,” Smith said.

The petunia – also a member of the tomato family – is of particular interest in sorting out this mystery, as it has a huge variation in colors.

Researchers hope that discovering how plants synthesize pigment compounds might provide clues for future drug discovery research. It will also satisfy scientists’ burning curiosity about how roses became red and violet became blue – a curiosity that is sparked anew every time they hear someone recite the classic poem.

By Dawn Henderson, Earth.com Staff Writer

Source: Stacy Smith, University of Colorado Boulder

National Science Foundation