Biology Physiology

Researchers from Nano Life Science Institute (WPI-NanoLSI), Kanazawa University report in Nature Communications that TMEM16F, a transmembrane protein that facilitates the passive movement of phospholipids and ions across membranes, explores a larger conformational landscape than previously thought to perform its unique functions. The finding refines our molecular understanding of crucial physiological processes such as blood coagulation and COVID-19 pathogenesis, and highlights the importance of probing membrane proteins in native-like environments.

Researchers at Nano Life Science Institute (WPI-NanoLSI), Kanazawa University report in Nature Communications a high-speed atomic force microscopy study of the structural dynamics of sodium ion channels in cell membranes. The findings provide insights into the mechanism behind the generation of cell-membrane action potentials.

Researchers at Kanazawa University report in Nature Communications how calcium ions can block sodium ion channels located in cell membranes. Structural analysis and computer simulations made it possible to identify where and why calcium ions get stuck.

A research team from the Graduate School of Rehabilitation Science at Osaka Metropolitan University investigated the electrophysiological benefits of working in the presence of others from the perspectives of brain and autonomic nervous system activity. The researchers found that parasympathetic activity—which indicates relaxation—was significantly higher when two individuals were working separately than when one individual was working alone. This suggests that arranging the former condition in occupational therapy for individuals with high levels of tension or anxiety in clinical settings may potentially help alleviate these feelings.

Researchers from Osaka University found that the binding of two proteins—Polydom and Tie1—is essential for lymphatic cell migration in the remodeling of lymphatic vessels, which transport molecules around the body. A better understanding of the development and remodeling of the lymphatic system will lead to better therapeutic options for diseases such as lymphedema, which is common in cancer patients and currently has no cure.

Researchers from Osaka University identified a subset of fibroblastic reticular cells (FRCs) that simultaneously express two proteins, Aldh1a2 and Tie2, making them unique to areas of the omentum called milky spots. Genetic depletion of these cells caused structural disruption of milky spots. The FRCs were critical to the abdominal immune system as they regulated CXCL12 levels, a molecule necessary for lymphocyte recruitment from blood circulation. These insights can help develop novel treatments for intra-abdominal infections.

Researchers from Osaka University found that Ca2+ signaling simultaneously performed signal amplification and olfactory adaptation. The results demonstrated that this mysterious phenomenon was segregated inside the cilium. A novel system was used to observe changes in Ca2+ dynamics inside the thin structure of a cilium. Unveiling the mystery of Ca2+ signaling segregation further clarifies the mechanisms underlying the human sense of smell.

In hepatic steatosis, hepatocytes "die," resulting in liver damage. Severe steatosis increases hepatocellular deaths, thus aggravating liver damage. The mechanism is unclear. Using mice, we show that mild steatosis causes apoptosis whereas severe steatosis predominantly causes necroptosis leading to cell rupture. This induces strong inflammation and new cell death, producing further liver damage. We reveal the transcription factor ATF3 to be involved in this process. Our results are expected to contribute to therapeutic method development.

A research group at the Osaka Metropolitan University Graduate School of Science has revealed a new system that allows them to control the behavior of the nematode worm Caenorhabditis elegans, using two different animal opsins, a type of light-sensitive protein. The first opsin was expressed in the worms’ sensory cells responsible for triggering avoidance behavior, making the worms move. This opsin was found to be approximately 7,000 times more sensitive to white light than the commonly used optogenetic protein channelrhodopsin-2. Likewise, a UV-sensitive opsin was expressed in the worms’ motor neurons, causing the worms to stop when exposed to UV light and start moving again when exposed to green light. Both opsins tested can be switched on and off repeatedly without breaking down, making them robust tools for future research, including the field of drug discovery.

A research group has revealed that amyloid-β (Aβ) detected in blood is secreted from peripheral tissues (pancreas, adipose tissue, skeletal muscle, liver, etc.) that are sensitive to glucose and insulin. Also, that Aβ secreted from peripheral tissues acts as a regulator on pancreatic β-cells to suppress insulin secretion. The results of this study indicate that blood Aβ levels fluctuate significantly with diet, and special care should be taken when using blood samples as a diagnostic marker for Alzheimer's disease, such as taking blood samples during fasting.

Using the lamprey, researchers from Japan analyzed the photosensory mechanism of the pineal organ, also called the pineal gland, in non-mammalian vertebrates and discovered a novel mechanism of pineal color discrimination (two-cell system) in which two types of photoreceptor cells, each containing two different opsins, are used to detect color. This discovery may provide insight into the evolution of color detection in other animals, including color vision in humans.

Researchers from Osaka City University show the benefits of mixing alginic acid with calcium phosphate cement (CPC), a common bone replacement material, with in vitro and in vivo studies. The biopolymer is shown to improve the setting time and compressive strength of CPC, as well as help it acquire porosity – which allows cells to enter the defected area and grow new bone.

Researchers reveal the path of information received by the hippocampus. Using optogenetics during large-scale recordings of rat subiculum, they discovered that the subiculum distributes information from the hippocampus to 4 downstream regions of the brain. They observed that the theta and sharp-wave/ripples in the subiculum controlled information transmission with millisecond precision according to the target region. This provides the foundation for a comprehensive understanding of the hippocampal memory system.

Collecting liver tissue from 22 postoperative patients with long-term post-Fontan surgery, researchers have found a specific liver fibrosis to develop from the sinusoidal region which is difficult to accurately assess by conventional examination methods (ultrasound elastography and blood tests).

Pregnant mice fed diets high in omega-6 fats and low in omega-3 fats are shown in a new study to produce offspring whose brains had a higher level of dopamine-producing neurons—the neurological reward system. These mice went on to chase hyper-caloric diets, suggesting that the fats in a pregnant mother's diet may control the eating habits of her children, and potentially offering a new obesity-prevention strategy.

Scientists from the Daegu Gyeongbuk Institute of Science and Technology, Republic of Korea, discover a new way to diagnose Alzheimer’s disease by analyzing the levels of specific proteins in nasal discharge. This simple and inexpensive method could help in timely diagnosis of Alzheimer’s disease, in order to start treatment as soon as possible, thus delaying disease progression.

A recent study, affiliated with South Korea's Ulsan National Institute of Science and Technology (UNIST) has identified the sleep-promoting effects of dietary threonine, as well as its neurobiological principle.