Dual-specificity phosphatases 13 and 27 as key switches in muscle stem cell transition from proliferation to differentiation.

Muscle regeneration depends on muscle stem cell (MuSC) activity. Myogenic regulatory factors, including myoblast determination protein 1 (MyoD), regulate the fate transition of MuSCs. However, the direct target of MYOD in the process is not completely clear.

Magnetic resonance elastography for the prediction of hepatocellular carcinoma in chronic hepatitis B.

Background And Aim: Magnetic resonance elastography (MRE) is used for the evaluation of liver fibrosis; however, it remains unclear whether MRE-based liver stiffness is associated with hepatocellular carcinoma (HCC) development, particularly in patients with chronic hepatitis B.

Methods: A total of 504 patients with chronic hepatitis B receiving MRE were enrolled. The was the association between MRE-based liver stiffness and HCC.

Impact of immune-related adverse events in patients with hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

Background And Aim: Immune checkpoint inhibitors pose the risk of immune-related adverse events (irAEs). Recent data suggest that irAEs may be associated with a favorable prognosis. This study aimed to investigate and analyze the association between these adverse events and the clinical benefits in patients with unresectable hepatocellular carcinoma.

Concordance between metabolic dysfunction-associated steatotic liver disease and nonalcoholic fatty liver disease.

Aim: A multisociety consensus group proposed a new nomenclature for metabolic dysfunction-associated steatotic liver disease (MASLD). Although patients with nonalcoholic fatty liver disease (NAFLD) are expected to be reclassified as patients with MASLD under the new nomenclature, the concordance between MASLD and NAFLD remains unclear. Moreover, waist circumference could be adjusted by ethnicity for diagnosing MASLD; however, there are limited data on the optimal waist circumference in the Japanese population.

Lunar gravity prevents skeletal muscle atrophy but not myofiber type shift in mice.

Skeletal muscle is sensitive to gravitational alterations. We recently developed a multiple artificial-gravity research system (MARS), which can generate gravity ranging from microgravity to Earth gravity (1 g) in space. Using the MARS, we studied the effects of three different gravitational levels (microgravity, lunar gravity [1/6 g], and 1 g) on the skeletal muscle mass and myofiber constitution in mice.

Large Maf transcription factor family is a major regulator of fast type IIb myofiber determination.

Myofibers are broadly characterized as fatigue-resistant slow-twitch (type I) fibers and rapidly fatiguing fast-twitch (type IIa/IIx/IIb) fibers. However, the molecular regulation of myofiber type is not entirely understood; particularly, information on regulators of fast-twitch muscle is scarce. Here, we demonstrate that the large Maf transcription factor family dictates fast type IIb myofiber specification in mice.

Changes in metabolism and vestibular function depend on gravitational load in mice.

The vestibular system is known to participate in controlling posture and metabolism. Different gravitational environments, including microgravity or hypergravity, cause plastic alteration of the vestibular system, and plasticity is important for adaptation to a novel gravitational environment. However, it is unclear whether the degree of change in vestibular-related physiological function depends on gravitational loading.

Sarcopenia affects activities of daily living recovery and hospitalization costs in older adults in convalescent rehabilitation wards.

Purpose: This study aimed to investigate the impact of sarcopenia on activities of daily living (ADL) recovery and hospitalization costs in older patients admitted to convalescent rehabilitation wards.

Methods: This prospective cohort study included 104 patients aged ≥ 65 years who were admitted to convalescent rehabilitation wards. The primary outcome was ADL recovery as evaluated by the Functional Independence Measure (FIM) efficiency during hospitalization, and the secondary outcome was hospital-related costs.

Nuclear factor E2-related factor 2 (NRF2) deficiency accelerates fast fibre type transition in soleus muscle during space flight.

Microgravity induces skeletal muscle atrophy, particularly in the soleus muscle, which is predominantly composed of slow-twitch myofibre (type I) and is sensitive to disuse. Muscle atrophy is commonly known to be associated with increased production of reactive oxygen species. However, the role of NRF2, a master regulator of antioxidative response, in skeletal muscle plasticity during microgravity-induced atrophy, is not known.

Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment.

Spaceflight causes a decrease in skeletal muscle mass and strength. We set two murine experimental groups in orbit for 35 days aboard the International Space Station, under artificial earth-gravity (artificial 1 g; AG) and microgravity (μg; MG), to investigate whether artificial 1 g exposure prevents muscle atrophy at the molecular level. Our main findings indicated that AG onboard environment prevented changes under microgravity in soleus muscle not only in muscle mass and fiber type composition but also in the alteration of gene expression profiles.

Author Correction: Nrf2 contributes to the weight gain of mice during space travel.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Nrf2 contributes to the weight gain of mice during space travel.

Space flight produces an extreme environment with unique stressors, but little is known about how our body responds to these stresses. While there are many intractable limitations for in-flight space research, some can be overcome by utilizing gene knockout-disease model mice. Here, we report how deletion of Nrf2, a master regulator of stress defense pathways, affects the health of mice transported for a stay in the International Space Station (ISS).

Mice lacking core 1-derived O-glycan in podocytes develop transient proteinuria, resulting in focal segmental glomerulosclerosis.

The glomerular filtration barrier is composed of podocytes, glomerular basement membrane, and endothelial cells. Disruption of these structures causes several glomerular injuries, such as focal segmental glomerulosclerosis (FSGS). The surface of podocyte apical membranes is coated by negatively charged sialic acids on core 1-derived mucin-type O-glycans.

MAFB is dispensable for the fetal testis morphogenesis and the maintenance of spermatogenesis in adult mice.

The transcription factor MAFB is an important regulator of the development and differentiation of various organs and tissues. Previous studies have shown that MAFB is expressed in embryonic and adult mouse testes and is expected to act as the downstream target of retinoic acid (RA) to initiate spermatogenesis. However, its exact localization and function remain unclear.

Postnatal lethality and chondrodysplasia in mice lacking both chondroitin sulfate N-acetylgalactosaminyltransferase-1 and -2.

Chondroitin sulfate (CS) is a sulfated glycosaminoglycan (GAG) chain. In cartilage, CS plays important roles as the main component of the extracellular matrix (ECM), existing as side chains of the major cartilage proteoglycan, aggrecan. Six glycosyltransferases are known to coordinately synthesize the backbone structure of CS; however, their in vivo synthetic mechanism remains unknown.

Incomplete clearance of apoptotic cells by core 1-derived O-glycan-deficient resident peritoneal macrophages.

The core 1 β1,3-galactosyltransferase-specific molecular chaperon (Cosmc) is essential for the synthesis of the core 1 structure of mucin-type O-glycans. To clarify the physiological role of core 1-derived O-glycans in macrophages, we exploited the LysM-Cre transgene to generate a conditional Cosmc mutant allele (conditional Cosmc knockout; cKO) in myeloid cells. cKO mice developed normally with no gross phenotypic abnormalities or abnormal peripheral blood counts.

Ground-based assessment of JAXA mouse habitat cage unit by mouse phenotypic studies.

The Japan Aerospace Exploration Agency developed the mouse Habitat Cage Unit (HCU) for installation in the Cell Biology Experiment Facility (CBEF) onboard the Japanese Experimental Module ("Kibo") on the International Space Station. The CBEF provides "space-based controls" by generating artificial gravity in the HCU through a centrifuge, enabling a comparison of the biological consequences of microgravity and artificial gravity of 1 g on mice housed in space. Therefore, prior to the space experiment, a ground-based study to validate the habitability of the HCU is necessary to conduct space experiments using the HCU in the CBEF.

Activation of the Small G Protein Arf6 by Dynamin2 through Guanine Nucleotide Exchange Factors in Endocytosis.

The small G protein Arf6 and the GTPase dynamin2 (Dyn2) play key roles in clathrin-mediated endocytosis (CME). However, their functional relationship remains obscure. Here, we show that Arf6 functions as a downstream molecule of Dyn2 in CME.