PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION

Sulfur: the consequences

How sulfur metabolism may have paved the way for the evolution of multicellularity

Sulfur: the consequences
2021-02-24
(Press-News.org) The transition from single-celled organisms to multicellular ones was a major step in the evolution of complex life forms. Multicellular organisms arose hundreds of millions of years ago, but the forces underlying this event remain mysterious. To investigate the origins of multicellularity, Erika Pearce's group at the MPI of Immunobiology and Epigenetics in Freiburg turned to the slime mold Dictyostelium discoideum, which can exist in both a unicellular and a multicellular state, lying on the cusp of this key evolutionary step. These dramatically different states depend on just one thing - food.

A core question of Pearce's lab is to answer how changes in metabolism drive cell function and differentiation. Usually, they study immune cells to answer this question, however, when first author Beth Kelly joined the group they decided to shift focus. "We figured that if we were interested in how nutrient availability induces changes in how cells function, there was no better organism to study than Dicty, where starvation causes cells to go from existing on their own to forming a multicellular organism. This is an immense shift in biology", Erika Pearce said.

Starvation drives multicellular aggregation of this social amoeba

Simply by depriving D. discoideum of its food supply, they could turn this organism from single cells into a multicellular aggregate, allowing them to examine the factors driving this multicellularity. The aggregate behaves as a complex, multicellular organism, with individual cells specializing to having different functions, and moving as a whole. Multicellular D. discoideum eventually form a protective spore, allowing the population to survive starvation.

Starving D. discoideum induce a rapid burst of reactive oxygen species (ROS) production. ROS are small molecules that are made by our cells, but were also used for signaling early in evolution, before more complex, receptor-based systems existed. However, when ROS levels are too high, they become damaging, oxidizing proteins and nucleic acids, eventually causing cells to die. So, an increase in ROS is generally accompanied by the production of antioxidants to control these ROS. Beth Kelly noted, "in our case, production of the antioxidant glutathione increased to counter the massive ROS burst upon starvation. If we gave the starving slime mold extra glutathione, we were able to block this increase in ROS and, importantly, stop the formation of the multicellular aggregate, keeping the cells in a single-celled state."

Starving Dicty alter their metabolism

In turn, when they blocked glutathione production using an inhibitor, they found that instead of promoting an even faster aggregation, this reversed it, maintaining the single-celled state for longer. This suggested that some function of supplemented glutathione, other than antioxidant activity, was reversing the aggregation process. They carefully considered how glutathione is made. It consists of only three amino acids, cysteine, glycine, and glutamine. Kelly added each of these components individually back to starving cells and she found that only cysteine alone could reverse multicellular aggregation upon starvation.

What is unique about the biology of cysteine? It is one of only two amino acids that contain sulfur, and this sulfur is critical for a wide variety of processes in proliferating cells. It is used for making new proteins, is vital for enzyme activity, and supports metabolic processes for energy production. Limiting cysteine therefore limits sulfur supply, slowing growth and proliferation, and indicating that there are insufficient nutrients for these processes to continue. For Dictyostelium, this means that they should transition to a multicellular state, to form a spore that can survive this period of nutrient limitation, preserving the population.

Sulfur dictates cell function and multicellularity

It turned out that the loss of sulfur was the important process underlying this multicellularity, and that increasing ROS was a clever means for D. discoideum to achieve this end. By increasing ROS, starving Dictyostelium consequently increase glutathione production. "This in effect pulls cysteine in the cells into glutathione, limiting the use of its sulfur for proliferation and protein production. By artificially blocking glutathione production, or by providing extra cysteine to the starving cells, we could restore this sulfur supply, recovering proliferation and the single-celled state," Beth Kelly said. "Thus, we revealed how sulfur dictates a switch between the single-celled and multicellular states." Sulfur and oxygen were common, small elements in an ancient world, and this work reveals how they may have played a role in the origins of multicellularity.

"Beyond this, we think that our work has therapeutic implications for more complex organisms. Cancer cells are highly proliferative, and some cancer cells specifically preserve sulfur metabolism. Restricting or targeting sulfur metabolic processes in these cells may enhance anti-tumor immunity," Pearce said. Immune cells traffic through environments containing distinct nutrient mixtures, and immune cell function depends on metabolic pathway activity. Manipulating sulfur metabolism may be a means to modulate immune cell function. Overall, examining such conserved nutrient signaling pathways in the early eukaryote Dictyostelium will likely be highly informative for mammalian cell function.

INFORMATION:


[Attachments] See images for this press release:
Sulfur: the consequences

ELSE PRESS RELEASES FROM THIS DATE:

NCI study finds people with SARS-CoV-2 antibodies may have low risk of future infection

2021-02-24
People who have had evidence of a prior infection with SARS-CoV-2, the virus that causes COVID-19, appear to be well protected against being reinfected with the virus, at least for a few months, according to a newly published study from the National Cancer Institute (NCI). This finding may explain why reinfection appears to be relatively rare, and it could have important public health implications, including decisions about returning to physical workplaces, school attendance, the prioritization of vaccine distribution, and other activities. For the study, researchers at NCI, part of the National Institutes of Health, collaborated with ...

Yale scientists capture the choreography of a developing brain

Yale scientists capture the choreography of a developing brain
2021-02-24
The formation of a brain is one of nature's most staggeringly complex accomplishments. The intricate intermingling of neurons and a labyrinth of connections also make it a particularly difficult feat for scientists to study. Now, Yale researchers and collaborators have devised a strategy that allows them to see this previously impenetrable process unfold in a living animal -- the worm Caenorhabditis elegans, they report February 24 in the journal Nature. "Before, we were able to study single cells, or small groups of cells, in the context of the living C. elegans, and for relatively short periods of time," said Mark Moyle, an associate research scientist in neuroscience at Yale School of Medicine and first author of the study. "It has been a breathtaking experience to ...

Building a brain: Pioneering study reveals principles of brain tissue structure, assembly

2021-02-24
WOODS HOLE, Mass. -- Understanding how the brain works is a paramount goal of medical science. But with its billions of tightly packed, intermingled neurons, the human brain is dauntingly difficult to visualize and map, which can provide the route to therapies for long-intractable disorders. In a major advance published next week in Nature, scientists for the first time report the structure of a fundamental type of tissue organization in brains, called neuropil, as well as the developmental pathways that lead to neuropil assembly in the roundworm C. elegans. This multidisciplinary study ...

Costs associated with delirium in older adults after elective surgery

2021-02-24
What The Study Did: Medicare claims and clinical data were used to estimate health care costs associated with delirium in older adults one year after major elective surgery. Authors: Tammy T. Hshieh, M.D., M.P.H., of Brigham and Women's Hospital in Boston, is the corresponding author. To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (doi:10.1001/jamasurg.2020.7260) Editor's Note: The article includes conflicts of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support. INFORMATION: Media advisory: The full study ...

Association of SARS-CoV-2 seropositive antibody test with risk of future infection

2021-02-24
What The Study Did: Researchers use a large set of clinical laboratory data linked to other clinical information such as claims to investigate the relationship between SARS-CoV-2 antibody status and subsequent nucleic acid amplification test (NAAT) results in an effort to understand how serostatus may predict risk of reinfection. Authors: Lynne T. Penberthy, M.D., M.P.H., of the National Cancer Institute at the National Institutes of Health in Rockville, Maryland, is the corresponding author. To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (doi:10.1001/jamainternmed.2021.0366) Editor's ...

Researchers take aim at the evolution of traditional technologies

Researchers take aim at the evolution of traditional technologies
2021-02-24
In the last 60,000 years, humans have emerged as an ecologically dominant species and have successfully colonized every terrestrial habitat. Our evolutionary success has been facilitated by a heavy reliance on an ever-advancing technology. Understanding how human technology evolves is crucial to understanding why humans have enjoyed such unprecedented evolutionary success. ASU doctoral graduate Jacob Harris, working with ASU researcher Robert Boyd and Brian Wood from the University of California Las Angeles and the Max Planck Institute for Evolutionary Anthropology, are interested in the role of causal ...

Childhood ADHD, risk of developing psychotic disorder

2021-02-24
What The Study Did: This study combined the results of 12 studies with 1.8 million participants to examine the association between attention-deficit/hyperactivity disorder (ADHD) in childhood and adolescence and the subsequent risk of developing a psychotic disorder. Authors: Mikaïl Nourredine, M.D., M.Sc., of the Hospices Civils de Lyon in Lyon, France, is the corresponding author. To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/ (10.1001/jamapsychiatry.2020.4799) Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and ...

Study shows economic impact of post-op delirium

2021-02-24
BOSTON (February 24, 2021) - Results of a study published today in JAMA Surgery reveal the impact post-operative delirium has on health care costs in the U.S. Data from the study shows that if delirium were prevented or made less severe for patients, it could reduce health care costs by $33 billion per year, that is, $44,300 per patient per year. Severe delirium resulted in an additional $56,500 per patient per year, as compared to routine health care costs for older post-operative patients. Tammy Hshieh, M.D., M.P.H., Adjunct Scientist, and Ray Yun Gou, M.A., Data Scientist II, both with the Aging Brain Center in the Hinda and Arthur Marcus Institute for Aging Research at Hebrew SeniorLife, are co-first authors. Sharon K. Inouye, M.D., M.P.H., Director ...

Daily emails about chemicals in tobacco lead some smokers to consider quitting

Daily emails about chemicals in tobacco lead some smokers to consider quitting
2021-02-24
CHAPEL HILL, N.C.--For the last decade, the U.S. Food and Drug Administration has required tobacco manufacturers and importers to report the levels of harmful and potentially harmful chemicals found in their tobacco products and tobacco smoke. The idea was to educate the public and ultimately to decrease tobacco use, but little research has demonstrated if such information can impact on people's decisions to quit smoking. A new study from the University of North Carolina at Chapel Hill has found that smokers who saw messages about tobacco chemicals with associated ...

Reactivating aging stem cells in the brain

Reactivating aging stem cells in the brain
2021-02-24
The stem cells in our brain generate new neurons throughout life, for example in the hippocampus. This region of the brain plays a key role for a range of memory processes. With increasing age, and in patients suffering from Alzheimer's disease, the hippocampus' ability to create new neurons declines steadily - and with it, its memory functions. Distribution of age-dependent cell damage A study conducted by the research group of Sebastian Jessberger, a professor at the Brain Research Institute of the University of Zurich, shows how the formation of new neurons is impaired with advancing age. Protein structures in the nuclei of neural stem cells make sure that harmful proteins accumulating ...

LAST 30 PRESS RELEASES:

Crop rotations with beans and peas offer more sustainable and nutritious food production

Five research-backed steps to a pro-vaccination social media campaign

1 in 4 parents give youth sports low rankings for enforcement of COVID-19 guidelines

Doctors still reluctant to prescribe medical cannabis: McMaster

Influence of sea surface temperature in the Indian Ocean on air quality in the Yangtze River Delta region

Frog species with 6 sex chromosomes offer new clues on evolution of complex XY systems

Study reveals the 3D structure of human uterine endometrium and adenomyosis tissue

ETRI develops a haptic film activated by LEDs

Researchers' work will help the pipeline industry limit the destructive power of bubbles

E-cigarettes with a cigarette-like level of nicotine are effective in reducing smoking

Deep Learning model developed at UHN to maximize lifespan after liver transplant 

Convenience over reputation: Study looks at how older adults pick a doctor

Ocean bacteria release carbon into the atmosphere

Spotting cows from space

Scientists watch 2D puddles of electrons emerge in a 3D superconducting material

Research suggests SEC's increasing focus on terrorism may limit financial oversight

Plastic planet: Tracking pervasive microplastics across the globe

Gut epithelium muscles up against infection

Scientists discover three liquid phases in aerosol particles

New mechanism identified behind blindness in older adults

Common approach to diversity in higher education reflects preferences of white Americans

Study reveals cancer immunotherapy patients at most risk of life-threatening side effects

Study reveals crucial details on skin-related side effects of cancer immune therapies

Researchers identify surface protein as a new osteosarcoma therapeutic target for antibody-drug conjugates

Differences in B cell responses to coronaviruses and other pathogens in children and adults

Bottom-up is the way forward for nitrogen reduction at institutions

Road salts and other human sources are threatening world's freshwater supplies

Researchers engineer probiotic yeast to produce beta-carotene

Spanking may affect the brain development of a child

UConn researchers find bubbles speed up energy transfer

[Press-News.org] Sulfur: the consequences
How sulfur metabolism may have paved the way for the evolution of multicellularity