UC Irvine research team identifies glycosylation enzyme critical in brain formation

Lisa Flanagan, professor of neurology
Photo Credit: Courtesy of University of California, Irvine

The MGAT5 glycosylation enzyme plays a crucial role in brain development, according to a study by University of California, Irvine researchers, a discovery that may contribute to new therapeutic purposes for neural stem cells.

Neurons, astrocytes and oligodendrocytes are the final mature cells of the brain and spinal cord formed by neural stem cells. Each has distinct and key functions. Neurons transmit signals, astrocytes help modify those signals, and oligodendrocytes keep the signals from degrading. When any cells make proteins or fats that end up on the cell surface, they often add small sugar molecules. The team tested whether this internal process – called glycosylation – affects how neural stem cells form mature brain cells.

The study, published in the journal Stem Cell Reports, found that during glycosylation, the MGAT5 enzyme significantly regulates the formation of neurons and astrocytes from neural stem cells. Neural stem cells that don’t have MGAT5 make more neurons and fewer astrocytes during the very early stages of brain development, altering its structure. These changes may contribute to later aberrant behavior patterns, including abnormal social interactions and repetitive actions.

Warm Ice Age” Changed Climate Cycles

The “Joides Resolution” research vessel – in the port of Lisbon – has been used since 1985 as part of the International Ocean Discovery Program for scientific drilling. The drill cores used in the current “warm ice age” study were taken during an expedition in the Gulf of Cádiz and off of southern Portugal. 
Photo Credit:  André Bahr

Earth scientists identify pivotal step in the Earth’s later climate development

Approximately 700,000 years ago, a “warm ice age” permanently changed the climate cycles on Earth. Contemporaneous with this exceptionally warm and moist period, the polar glaciers greatly expanded. A European research team including Earth scientists from Heidelberg University used recently acquired geological data in combination with computer simulations to identify this seemingly paradoxical connection. According to the researchers, this profound change in the Earth’s climate was responsible for the change in the climate cycles, thus representing a critical step in the later climate evolution of our planet.

Contraception, evolution and the genetic maintenance of same-sex sexual behavior

A gene is a basic unit of heredity. It is a segment of DNA that codes for a specific protein or RNA molecule. Genes are responsible for passing on traits from parents to their offspring. 
Image Credit: THAVIS 3D

Evolution depends on genes being passed down through the generations via reproduction, and same-sex sexual behavior does not result in offspring.

So, why haven’t the many genes associated with same-sex sexual behavior, known as SSB-associated genes, been purged from the human genome over time? It’s a question that has perplexed scientists for decades, one that’s explored anew in a Proceedings of the National Academy of Sciences study by two University of Michigan biologists.

One possible explanation for the persistence of SSB-associated genes is that they have more than one function, a concept called pleiotropy. Perhaps SSB-associated genes are advantageous to heterosexuals in some way, helping them to have more children.

Support for this idea includes a 2021 Nature Human Behaviour study by University of Queensland biologist Brendan Zietsch and colleagues. They presented evidence that heterosexuals carrying SSB-associated genes have more sexual partners than those not carrying the genes. This could confer an evolutionary advantage, because more sexual partners could translate into more children, according to the Zietsch et al. study.

Scientists use X-ray beams to determine role of zinc in development of ovarian follicles

Elemental map of zinc measured by synchrotron-based X-ray fluorescence microscopy demonstrates the increase in total zinc content, and the differential distribution of zinc in ovarian follicles during primordial-through-secondary-stage development. The color scale bar represents the minimum and maximum zinc contents (µg/cm2). Scale bar=10 μm.
Image Credit: NIH/Yu-Ying Chen

To make a baby, first you need an egg. To have an egg, there needs to be a follicle. And in the very beginning of follicle development, there needs to be zinc.

The last of those statements represents the new findings reported recently by a team of researchers from Michigan State University, Northwestern University and the U.S. Department of Energy’s (DOE) Argonne National Laboratory. The research builds upon earlier work looking at the role of zinc in fertilization and uncovers the importance of the metal earlier in the process of ovulation.

The results were reported in a paper in the Journal of Biological Chemistry that looked at the role of zinc in follicle development. The researchers, led by Teresa Woodruff and Tom O’Halloran of Michigan State University, used the Bionanoprobe at Argonne’s Advanced Photon Source (APS) to examine zinc and other trace elements in the egg cell itself as well as surrounding somatic cells.

Insight into brain’s waste clearing system may shed light on brain diseases

The image shows a microscopic image revealing the enhanced glymphatic transport of an intranasally delivered tracer (red), achieved using ultrasound combined with microbubbles.
Image Credit: Chen lab

Like the lymphatic system in the body, the glymphatic system in the brain clears metabolic waste and distributes nutrients and other important compounds. Impairments in this system may contribute to brain diseases, such as neurodegenerative diseases and stroke.

A team of researchers in the McKelvey School of Engineering at Washington University in St. Louis has found a noninvasive and nonpharmaceutical method to influence glymphatic transport using focused ultrasound, opening the opportunity to use the method to further study brain diseases and brain function. Results of the work are published in Proceedings of the National Academy of Sciences May 15, 2023.

Hong Chen, associate professor of biomedical engineering in McKelvey Engineering and of neurological surgery in the School of Medicine, and her team, including Dezhuang (Summer) Ye, a postdoctoral research associate, and Si (Stacie) Chen, a former postdoctoral research associate, found the first direct evidence that focused ultrasound, combined with circulating microbubbles — a technique they call FUSMB — could mechanically enhance glymphatic transport in the mouse brain. 

Focused ultrasound can penetrate the scalp and skull to reach the brain and precisely target a defined region within the brain. In previous work, Chen’s team found that microbubbles injected into the bloodstream amplify the effects of the ultrasound waves on the blood vessels and generate a pumping effect, which helps with the accumulation of intranasally-delivered agents in the brain, such as drugs or gene therapy treatments.

South Africa’s desert-like interior may have been more inviting to our human ancestors

Illustration Credit: Scientific Frontline

Lining the Cape of South Africa and its southern coast are long chains of caves that nearly 200,000 years ago were surrounded by a lush landscape and plentiful food.

During a glacial phase that lasted between 195,000 to 123,000 years ago, these caves served as refuge to a group of humans that some researchers think were the only people to survive this ice age, called Marine Isotope Stage Six, or MIS6. And in this coastal region, a lot of archaeological research has taken place. Of less interest to archaeologists has been the interior of South Africa, which was thought to be an uninhabited, inhospitable place during at least two waves of ice ages, MIS3 and 2.

Now, a study has shown that the region might have been more fertile and temperate during these two glacial periods than previously thought, and that the region likely played host to human populations living around a series of paleolakes. The study, led by University of Michigan archaeologist Brian Stewart, provides a more comprehensive timeline of the age and stages of these lakes, and shows human fingerprints across the region. The research, funded by the National Geographic Society, is published in the journal PNAS.

Mast cells have an important impact on the development of chronic myeloid leukemia

Microscopic image of bone marrow from a mouse with CML showing an unusually high number of mast cells (purple).
Image Source / Credit: Sebastian Halbach

Research team at the University of Freiburg traces the origin of proinflammatory cytokines

Chronic myeloid leukemia (CML) is a type of blood cancer that arises from malignant changes in blood-forming cells of the bone marrow. It mainly occurs in older individuals and represents about 20 percent of all adult leukemia cases. A research team led by Dr. Sebastian Halbach, Melanie Langhammer and Dr. Julia Schöpf from the Institute of Molecular Medicine and Cell Research at the University of Freiburg has now demonstrated for the first time that mast cells play a crucial role in the development of CML.  Mast cells could therefore serve as an additional therapeutic target in the clinic. “It was really impressive to see that mice lacking mast cells no longer developed severe CML,” says study leader Halbach. The results were recently published in the journal Leukemia.

Significantly elevated cytokine levels

Mast cells are cells of the immune system that play a decisive role in the defense against pathogens, but also in allergies. In this context, mast cells release inflammation inducing messenger molecules, so-called proinflammatory cytokines, which are crucial for the immune response. However, proinflammatory cytokines are also frequently found in the microenvironment of tumors and are suspected of decisively promoting cancer development. Using a mouse model for CML, the scientists were able to demonstrate for the first time that cytokines in CML could indeed originate from mast cells.

Monkeypox viruses relatively stable on surfaces

Cleaning surfaces with alcohol-based disinfectant is a good protection against infection.
Photo Credit: © RUB, Marquard

The virus remains infectious on steel surfaces for up to 30 days, but can be effectively deactivated by alcoholic disinfectants.

Pockenviruses are known to remain infectious in the area for a very long time. A study by the Molecular and Medical Virology Department at the Ruhr University Bochum showed that the temperature is very important: at room temperature, it can take up to eleven days until there is no longer a reproductive monkeypox virus on a stainless-steel surface, at four degrees Celsius even up to a month. Accordingly, it is particularly important to disinfect surfaces. According to the study, alcoholic disinfectants work well against monkeypox viruses. However, hydrogen peroxide-based disinfectants are not sufficiently effective. The team reports in Journal of infectious diseases.

Weekly observation

Since 2022, the monkey pox virus has been spreading from person to person. Even if the infection is primarily due to direct physical contact, it is possible to infect yourself via contaminated surfaces, for example in the household or in hospital rooms. "Pockenviren is known to remain infectious in the area for a very long time," explains Dr. Toni Meister from the Department of Molecular and Medical Virology at Ruhr University. “So far we have not known the exact times for monkey pox."

Brain research with organoids

Section of an electroporated brain organoid of a common marmoset. Green: electroporated cells that glow green due to the green fluorescent protein; magenta: neurons; gray: nuclei.
Photo Credit: Lidiia Tynianskaia

Scientists at the German Primate Center develop effective method to genetically modify brain organoids

Primates are among the most intelligent creatures with distinct cognitive abilities. Their brains are relatively large in relation to their body stature and have a complex structure. However, how the brain has developed over the course of evolution and which genes are responsible for the high cognitive abilities is still largely unclear. The better our understanding of the role of genes in brain development, the more likely it will be that we will be able to develop treatments for serious brain diseases. 

Researchers are approaching these questions by knocking out or activating individual genes and thus drawing conclusions about their role in brain development. To avoid animal experiments as far as possible, brain organoids are used as an alternative. These three-dimensional cell structures, which are only a few millimeters in size, reflect different stages of brain development and can be genetically modified. However, such modifications are usually very complex, lengthy and costly. Researchers at the German Primate Center (DPZ) – Leibniz Institute for Primate Research in Göttingen have now succeeded in genetically manipulating brain organoids quickly and effectively. 

Deficiency causes appetite for meat

A carnivorous leaf of Triphyophyllum peltatum with glands excreting a sticky liquid to capture insect prey.
Photo Credit: Traud Winkelmann / Universität Hannover

Under certain circumstances, a rare tropical plant develops into a carnivore. A research team from the universities of Hannover and Würzburg has now deciphered the mechanism responsible for this.

Triphyophyllum peltatum is a unique plant. Native to the tropics of West Africa, the liana species is of great interest for medical and pharmaceutical research due to its constituents: In the laboratory, this show promising medically useful activities against pancreatic cancer and leukemia cells, among others, as well as against the pathogens that cause malaria and other diseases.

However, the plant species is also interesting from a botanical perspective: Triphyophyllum peltatum is the only known plant in the world that can become a carnivore under certain circumstances. Its menu then includes small insects, which it captures with the help of adhesive traps in the form of secretion drops and digests with synthesized lytic enzymes.