Graphic by Maia Brown

North by Northwestern’s new series, Research Roundup shares and explains innovative and pioneering research projects conducted by Northwestern professors and students.

A new report shows how climate change is affecting the ecosystem of the Great Lakes region. NASA Twins Study finds that extended spaceflight affects the human gut microbiome. Northwestern researchers discover that disrupted circadian clock might protect the brain.

The impacts of climate change on the Great Lakes

Eighteen leading scientists and experts from Midwestern and Canadian universities and research institutions, including Northwestern’s own Professor Aaron Packman, assess the impact of climate change on the Great Lakes region. With more than 34 million people living within the Great Lakes Basin and relying on it for drinking water, commerce and recreation, scientists are trying to find challenges the region faces and possible solutions to the ominous effects.

According to the report released on March 22, the Great Lakes region faces multifaceted challenges. The annual mean temperature and precipitation both increased rapidly. These increases will cause more extreme weather like flooding, heat waves, drought and intense summer storms. People living in the Great Lakes region will suffer from agricultural losses, air pollution, poorer public health and lower water quality. Climate change will also lead to the increase of bacteria levels and invasive species in the lakes and damage the lake ecology. Fluctuating lake levels will affect shipping safety. It will also affect boating activities and other recreation in the Great Lakes region. People living in the Great Lakes region have already experienced some of these effects, and scientists expect that these impacts will continue and expand in the future.

The report concludes that “scientific analyses clearly show that climate change has already greatly affected the region and that these impacts will continue and expand as the pace of climate change accelerates.” Scientists aim to educate policymakers and the public to promote changes in policies and behaviors in order to protect natural resources in the Great Lakes region.

NASA Twins Study

A Northwestern University research team participated in the NASA Twins Study to find out how spaceflight affects the human body. Northwestern professors Fred Turek and Martha Vitaterna studied the changes in the composition of bacteria in the gut microbiome of Scott Kelly, the first American astronaut to spend nearly one full year in space. They studied his gut microbiome sample before, during and after the flight and compared his samples with samples from his twin brother, retired astronaut Mark Kelly. Mark stayed on Earth to provide a baseline for observation. Turek and Vitaterna found a shift in the ratio of two major categories of bacteria in Scott’s gut microbiome during the flight. They observed that the diversity of bacteria in his microbiome did not change, which was encouraging for researchers. “There are studies that link changes in the gut microbiome with neurological and physiological conditions, like Alzheimer’s disease, Parkinson’s disease, autism and schizophrenia,” Professor Vitaterna said.

Although scientists still do not know whether this shift in the ratio of bacteria is good or bad, they find it important to fully understand these changes in the gut microbiome before sending people to longtime space travel. Bacteria in the gut play an important role in digestion, and gut health can affect the function of the rest of the human body. Scientists have recently found that changes in the gut microbiome can lead to changes in bones, muscles and the brain. Researches are not sure what caused this shift in Scott’s gut microbiome. Possible explanations include microgravity, increased radiation, shifts in circadian rhythms, decreased sleep time, lack of air circulation, the stress of living in an enclosed space and an altered diet. Northwestern’s research was one out of 10 studies that was published in one comprehensive paper in the journal Science on April 12.

The role of the circadian clock in neurodegenerative diseases

Patients with neurodegenerative diseases often suffer from disrupted sleep-wake cycles that make them struggle to stay asleep or sleep more than usual. These disrupted cycles can also cause nighttime wandering and even Alzheimer’s. Northwestern University researchers found that knocking down, or in other words, reducing the circadian clock-controlled gene protects the brain from neurodegenerative diseases. This finding provides potential new ways to prevent or slow down the progression of neurodegenerative diseases.

Weinberg professor Ravi Allada and his team changed the fruit flies’ circadian rhythms to try to understand the role of circadian disruption in neurodegenerative disease. They expected that giving the flies jet lag would create more damage to the brain. To their surprise, though, they discovered that the stress caused by jet lag actually protected the neuron in the brain. This shocking discovery led them to further their research to study clock-controlled genes and see if any of those genes could similarly protect the brain from neurodegenerative diseases. They locked on a gene that encodes the “heat shock organizing protein,” or “hop” for short.

Hop is controlled by the circadian clock, and it is responsible for protein folding. Protein folding is the physical process by which the protein acquires its characteristic and functional structure.  Misfolded proteins in the brain can result in many different neurodegenerative diseases. Intuitively, researchers thought that knocking down the gene that helps proteins fold properly would make the disease worse. But again, they were surprised to find that inhibiting this gene protected the neurons, reduced the aggregation of diseased proteins from the protein misfolding process in the brain and restored the disrupted circadian clock of the flies. The result showed that although seemingly counterintuitive, providing a little bit of stress on the brain might be neuroprotective.