Publications by authors named "Takashi Ohira"

Chronic kidney disease (CKD) is a significant global health issue and often involves CKD-mineral and bone disorder (MBD) and sarcopenia. Plasminogen activator inhibitor-1 (PAI-1) is an inhibitor of fibrinolysis. PAI-1 has been implicated in the pathogenesis of osteoporosis and muscle wasting induced by inflammatory conditions.

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Tmem119 was identified as a bone anabolic factor in osteoblasts, however the roles of Tmem119 on bone repair have remained unknown. Therefore, we herein investigated the roles of Tmem119 on bone repair by examining the bone repair process after a femoral bone defect using Tmem119-deficient mice. In Tmem119-deficient mice, bone repair after a femoral bone defect was significantly delayed 10 and 14 days after bone injury in female and male mice with 3-dimensional micro-computed tomography analyses, respectively.

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Introduction: Glucocorticoids delay fracture healing and induce osteoporosis. Angiogenesis plays an important role in bone repair after bone injury. Plasminogen activator inhibitor-1 (PAI-1) is the principal inhibitor of plasminogen activators and an adipocytokine that regulates metabolism.

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Article Synopsis
  • * A study analyzed serum samples from patients with osteoporosis without fractures and those with osteopenia and fragility fractures, identifying six serum proteins that changed similarly between the two groups.
  • * One significant protein, ECM1, showed elevated levels in both groups and could potentially indicate the need for treatment; however, further larger studies are required to validate its effectiveness for early intervention.
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Physical inactivity associated with gravity unloading, such as microgravity during spaceflight and hindlimb unloading (HU), can cause various physiological changes. In this study, we attempted to identify serum proteins whose levels fluctuated in response to gravity unloading. First, we quantitatively assessed changes in the serum proteome profiles of spaceflight mice using mass spectrometry with data-independent acquisition.

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Heterotopic ossification (HO) is the process by which ectopic bone forms at an extraskeletal site. Inflammatory conditions induce plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis, which regulates osteogenesis. In the present study, we investigated the roles of PAI-1 in the pathophysiology of HO induced by trauma/burn treatment using PAI-1-deficient mice.

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Mechanical-unloading-induced skeletal muscle atrophy results in physical frailty and disability. Elucidating its mechanism is required to establish effective countermeasures for this muscle adaptation. First, we analyzed the proteome profile in the gastrocnemius (Gast) and soleus muscles of space-flown mice raised under microgravity or artificial 1- for 30 days, and found that the expression levels of fibrinolysis-related proteins were significantly elevated in the mechanical-unloaded muscles.

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The intermittent administration of parathyroid hormone (PTH) exerts potent bone anabolic effects, which increase bone mineral density (BMD) and reduce fracture risk in osteoporotic patients. However, the underlying mechanisms remain unclear. Tmem119 has been proposed as a factor that is closely linked to the osteoblast phenotype, and we previously reported that PTH enhanced the expression of Tmem119 in mouse osteoblastic cells.

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Article Synopsis
  • The study investigates how spaceflight impacts healthy tissue functions through changes in the serum proteome of six astronauts during a 6-month mission.
  • Researchers used data-independent acquisition mass spectrometry (DIA-MS) to identify 624 proteins related to bone metabolism, revealing a decrease in T-scores in dual-energy X-ray scans over time.
  • Findings suggest that specific proteins like ALPL, COL1A1, SPP1, and POSTN could serve as indicators of bone metabolism changes in space, advancing our understanding of biological adaptations to long-duration spaceflight.
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  • Gravity impacts the musculoskeletal health of elderly individuals by preventing muscle loss and improving bone density, which enhances quality of life.
  • Researchers analyzed the soleus muscle in mice under various gravity conditions, identifying specific proteins (Myl6b, Gpd1, Fbp2, Pvalb, Actn3) that respond to these gravity changes, indicating a shift towards slow-twitch muscle fibers.
  • Higher levels of Pvalb were found in the blood of mice and osteoporosis patients with muscle atrophy, suggesting it could be a key marker for evaluating muscle and bone health in seniors.
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  • Astronauts experience significant bone loss in microgravity, but the exact molecular mechanisms behind this are still not fully understood.
  • Researchers developed a sensitive mass spectrometry analysis system to study proteomic changes in mouse bones, successfully identifying 40 proteins with varying abundance due to the absence of gravity and 22 proteins unaltered by mechanical stimuli.
  • Notably, one protein, SPARCL1, may stimulate bone degradation processes, potentially revealing new insights into bone metabolism and the impact of mechanical forces on bones in space.
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Chronic obstructive pulmonary disease (COPD) causes sarcopenia and osteoporosis. However, the mechanisms underlying muscle and bone loss as well as the interactions between muscle and bone in the COPD state remain unclear. Therefore, we herein investigated the effects of the COPD state on muscle and bone in mice intratracheally administered porcine pancreatic elastase (PPE).

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Matrix vesicles (MtVs) are one of the extracellular vesicles (EVs) secreted by osteoblasts. Although MtVs have a classically-defined function as an initiator of ossification and recent findings suggest a role for MtVs in the regulation of bone cell biology, the effects of MtVs on bone repair remain unclear. In the present study, we employed collagenase-released EVs (CREVs) containing abundant MtVs from mouse osteoblasts.

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Extracellular vesicles (EVs) play crucial roles in physiological and pathophysiological processes. Although studies have described muscle-bone interactions via humoral factors, we reported that EVs from C2C12 muscle cells (Myo-EVs) suppress osteoclast formation. Current clinical evidence suggests that inflammation induces both sarcopenia and osteoporosis.

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The interactions between muscle and bone are noted in the clinical relationships between sarcopenia and osteoporosis. Myokines secreted from the skeletal muscles play roles in muscle-bone interactions related to various physiological and pathophysiological states. Although numerous evidence suggests that growth hormone (GH) influences both muscle and bone, the effects of GH on the muscle-bone interactions have remained unknown.

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Humoral factors that are secreted from skeletal muscles can regulate bone metabolism and contribute to muscle-bone relationships. Although extracellular vesicles (EVs) play important roles in physiological and pathophysiological processes, the roles of EVs that are secreted from skeletal muscles in bone repair have remained unclear. In the present study, we investigated the effects of the local administration of muscle cell-derived EVs on bone repair in control and streptozotocin-treated diabetic female mice.

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We reviewed the responses of the neuromuscular properties of mainly the soleus and possible mechanisms. Sensory nervous activity in response to passive shortening and/or active contraction, associated with plantar-flexion or dorsi-flexion of the ankle joints, may play an essential role in the regulation of muscle properties. Passive shortening of the muscle fibers and sarcomeres inhibits the development of tension, electromyogram (EMG), and afferent neurogram.

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Exercise is important for the prevention and treatment of sarcopenia and osteoporosis. Although the interactions between skeletal muscles and bone have recently been reported, the myokines linking muscle to bone during exercise remain unknown. We previously revealed that chronic exercise using treadmill running blunts ovariectomy-induced osteopenia in mice.

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Background: Chronic renal failure induces bone mineral disorders and sarcopenia. Skeletal muscle affects other tissues, including bone, by releasing myokines. However, the effects of chronic renal failure on the interactions between muscle and bone remain unclear.

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Article Synopsis
  • Short-chain fatty acids from non-digestible carbs like fructo-oligosaccharide (FOS) help maintain muscle mass and metabolism in the body.
  • A study on mice in microgravity (μ-g) showed that both soleus (Sol) and extensor digitorum longus muscles lost weight, with a shift in the Sol muscles toward faster-twitch fibers.
  • Despite some muscle loss, FOS ingestion appeared to lessen the impacts of μ-g by slowing down metabolic changes and reducing oxidative stress in Sol muscles.
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The partial gravity environment in space can negatively affect bone health. This survey aimed to study the reaction of different parts of the lower limb bones of rats to partial gravity and the effects of different degrees of gravity on these bony parts. We used 15 8-week-old male Wistar Hannover rats were used at the beginning of the experiment.

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Investigating protein abundance profiles is important to understand the differences in the slow and fast skeletal muscle characteristics. The profiles in soleus (Sol) and extensor digitorum longus (EDL) muscles in mice exposed to 1 g or 3 g for 28 d were compared. The biological implications of the profiles revealed that hypergravity exposure activated a larger number of pathways involved in protein synthesis in Sol.

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The regeneration of injured muscles is facilitated by intermittent heat stress. The 72-kDa heat shock protein (HSP72), the level of which is increased by heat stress, is likely involved in this effect, but the precise mechanism remains unclear. This study was conducted to investigate the localization and role(s) of HSP72 in the regenerating muscles in heat-stressed rats using immunohistochemistry.

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