The aminopeptidase LAP3 suppression accelerates myogenic differentiation via the AKT-TFE3 pathway in C2C12 myoblasts.

Skeletal muscle maintenance depends largely on muscle stem cells (satellite cells) that supply myoblasts required for muscle regeneration and growth. The ubiquitin-proteasome system is the major intracellular protein degradation pathway. We previously reported that proteasome dysfunction in skeletal muscle significantly impairs muscle growth and development. Furthermore, the inhibition of aminopeptidase, a proteolytic enzyme that removes amino acids from the termini of peptides derived from proteasomal proteolysis, impairs the proliferation and differentiation ability of C2C12 myoblasts. However, no evidence has been reported on the role of aminopeptidases with different substrate specificities on myogenesis. In this study, therefore, we investigated whether the knockdown of aminopeptidases in differentiating C2C12 myoblasts affects myogenesis. The knockdown of the X-prolyl aminopeptidase 1, aspartyl aminopeptidase, leucyl-cystinyl aminopeptidase, methionyl aminopeptidase 1, methionyl aminopeptidase 2, puromycine-sensitive aminopeptidase, and arginyl aminopeptidase like 1 gene in C2C12 myoblasts resulted in defective myogenic differentiation. Surprisingly, the knockdown of leucine aminopeptidase 3 (LAP3) in C2C12 myoblasts promoted myogenic differentiation. We also found that suppression of LAP3 expression in C2C12 myoblasts resulted in the inhibition of proteasomal proteolysis, decreased intracellular branched-chain amino acid levels, and enhanced mTORC2-mediated AKT phosphorylation (S473). Furthermore, phosphorylated AKT induced the translocation of TFE3 from the nucleus to the cytoplasm, promoting myogenic differentiation through increased expression of myogenin. Overall, our study highlights the association of aminopeptidases with myogenic differentiation.

Little involvement of recycled-amino acids from proteasomal proteolysis in de novo protein synthesis.

Myoblast integrity is essential for skeletal muscle regeneration. Many intracellular proteins are degraded by the proteasome and converted to amino acids by aminopeptidases through the protein degradation pathway. Although we previously reported its importance for myoblast integrity, the involved mechanism remains unclear. In this study, we focused on the reusability of proteolytic products to elucidate the regulatory mechanism of protein synthesis mediated by the proteasome and aminopeptidases. Proteasome inhibition decreased protein synthesis, but recycled-amino acids derived from proteasomal proteolysis were not reused for de novo protein synthesis in C2C12 myoblasts. On the other hand, proteasome and aminopeptidase inhibition decreased intracellular ATP levels in C2C12 myoblasts. Therefore, it was indicated that amino acids produced by these proteolytic systems may be reutilized for ATP production through its metabolism, not for de novo protein synthesis. These findings suggested the proteasome and aminopeptidases are thought to be involved in protein synthesis through intracellular energy production by recycled-amino acid metabolism, thereby maintaining myoblast integrity.

Impact of Antibody Cocktail Therapy Combined with Casirivimab and Imdevimab on Clinical Outcome for Covid-19 patients in A Real-Life Setting: A Single Institute Analysis

BackgroundRecent data from clinical trial suggest that antibody cocktail therapy, a combination of the monoclonal antibodies casirivimab and imdevimab, has been shown to rapidly reduce the viral load and markedly decrease the risk of hospitalization or death among high-risk patients with coronavirus disease 2019 (Covid-19). However, it remains unclear how effective in a real-life clinical setting the therapy is. MethodsWe retrospectively analyzed mild to moderate Covid-19 patients with one or more high-risk factors for severe disease who consecutively underwent the antibody cocktail therapy of the disease in our institute in June 2021 through early September 2021, compared to those with high-risk factors who were isolated in non-medical facilities consecutively during the same period, thereby being not given the antibody cocktail therapy there. The key outcome was the percentage of patients with Covid-19-related deterioration which needed additional medical interventions, such as oxygen support or other antiviral therapies. ResultsData from 55 patients with initially receiving antibody cocktail therapy and 53 patients with isolation into non-medical facilities are analyzed. 22 (41.5 %) of 53 patients with isolation facilities were finally hospitalized to receive medical interventions. On the other hand, 13 (23.6 %) of 55 patients with antibody cocktail therapy in our hospital subsequently underwent further medical interventions because of the progression. In multivariate analysis with variables of age, BMI, and high-risk factors, the antibody cocktail therapy significantly reduced 70 % in the need for further medical interventions compared to the initial isolation in the non-medical facilities (odds ratio=0.30, 95%CI [0.10-0.87], p=0.027). Furthermore, patients with 96% or above of SPO2 were significantly more favorable for the therapy than those with 95% or below of SPO2. ConclusionThe treatment of antibody cocktail was closely linked to reduction in the need for further medical interventions. The result indicates that the antibody cocktail therapy is associated with reducing the strain on hospitals, which is related to the improvement of medical management for public health care in Covid-19 pandemic era.

Cross-cultural Study about Cancer and Palliative Care in the Okinawa, Tohoku, and Tokyo Metropolitan Area

Background: Consideration of cultural aspects is important in medical care. We explored regional differences in cancer and palliative care among Okinawa, Tohoku, and Tokyo metropolitan area. Methods: We conducted a questionnaire survey of physicians involved in cancer medicine from September to November 2020. A total of 11 items related to physician experiences were rated using a 5-point Likert-type scale. Results: Responses were received from 553 physicians (187 in Okinawa, 219 in Tohoku, 147 in the Tokyo metropolitan area). In Okinawa, “When patients die, it is important that all family members are present at the last moment,” “Patients/family members primarily consult the elders of the family about the medical treatments,” “Family members hope the patients die at home, because the soul will not return when they die at the hospital,” “Patients/family members get advice from religious advisors about the medical treatments,” and “Family members wish to take the patient home when he/she is about to die and to confirm death at home” were significantly more frequently observed. In Tohoku, “Patients wish to be hospitalized at a specific season” was significantly more frequently reported. In Tohoku and Okinawa, “Patients hide cancer from neighbors and relatives” and “Elderly patients do not want treatment, because they cover the living expenses and education expenses for their children and grandchildren.” were significantly more frequently experienced. Conclusion: There are regional differences in cancer and palliative care in Japan. Being sensitive to the culture of the region is needed.

Hemilaminectomy for Removal of Extramedullary or Extradural Spinal Cord Tumors: Medium to Long-Term Clinical Outcomes

PURPOSE: Laminectomy is generally the treatment of choice for removal of spinal tumors. However, it has been shown that laminectomy may cause instability due to damage of posterior elements of the spinal column, which may induce subsequent kyphosis in the future. Therefore, to reduce the risk of deformity and spinal instability after laminectomy, hemilaminectomy has been used. However, the medium to long-term effects of hemilaminectomy on spinal sagittal alignment is not well understood. The present study was performed to evaluate the clinical outcomes, including spinal sagittal alignment of patients, associated with spinal cord tumors treated by surgical excision using hemilaminectomy. MATERIALS AND METHODS: Twenty hemilaminectomy operations at our institute for extramedullary or extradural spinal cord tumors in 19 patients were evaluated retrospectively with an average follow-up of 85 months (range, 40-131 months). Neurological condition was evaluated using the improvement ratio of the Japanese Orthopaedic Association Score (JOA score) for cervical, thoracic myelopathy, or back pain, and sagittal alignment by sagittal Cobb angle of the hemilaminectomied area. RESULTS: The mean improvement ratio of neurological results was 56.7% in the cervical spine (p < 0.01, n = 10), 26.3% in the thoracic spine (not significant, n = 5), and 48.6% in the lumbar spine (NS, n = 5). The sagittal Cobb angle was 4.3 +/- 18.0degrees in the preoperative period and 5.4 +/- 17.6degrees at the latest follow-up, indicating no significant deterioration. CONCLUSION: Hemilaminectomy is useful for extramedullary or extradural spinal cord tumors in providing fair neurological status and restoration of spinal sagittal alignment in medium to long-term follow-up.

Cantilever Transforaminal Lumbar Interbody Fusion for Upper Lumbar Degenerative Diseases (Minimum 2 Years Follow Up)

PURPOSE: To evaluate the clinical outcomes of cantilever transforaminal lumbar interbody fusion (c-TLIF) for upper lumbar diseases. MATERIALS AND METHODS: Seventeen patients (11 males, 6 females; mean +/- SD age: 62 +/- 14 years) who underwent c-TLIF using kidney type spacers between 2002 and 2008 were retrospectively evaluated, at a mean follow-up of 44.1 +/- 12.3 months (2 year minimum). The primary diseases studied were disc herniation, ossification of posterior longitudinal ligament (OPLL), degenerative scoliosis, lumbar spinal canal stenosis, spondylolisthesis, and degeneration of adjacent disc after operation. Fusion areas were L1-L2 (5 patients), L2-L3 (9 patients), L1-L3 (1 patient), and L2-L4 (2 patients). Operation time, blood loss, complications, Japanese Orthopaedic Association (JOA) score for back pain, bone union, sagittal alignment change of fusion level, and degeneration of adjacent disc were evaluated. RESULTS: JOA score improved significantly after surgery, from 12 +/- 2 to 23 +/- 3 points (p < 0.01). We also observed significant improvement in sagittal alignment of the fusion levels, from - 1.0 +/- 7.4 to 5.2 +/- 6.1 degrees (p < 0.01). Bony fusion was obtained in all cases. One patient experienced a subcutaneous infection, which was cured by irrigation. At the final follow-up, three patients showed degenerative changes in adjacent discs, and one showed corrective loss of fusion level. CONCLUSION: c-TLIF is a safe procedure, providing satisfactory results for patients with upper lumbar degenerative diseases.

MORPHOLOGICAL CHARACTERISTICS OF TRUNK MUSCLE GROUPS IN JAPANESE FEMALE ELITE JUDO ATHLETES / 体力科学

Using three-dimensional (3 D) imaging, we investigated the morphological characteristics of the M, latissiums dorsi (LD) and M, erector spinae (ES) of the dorsal trunk in judo athletes employing a computer graphics system on magnetic resonance imaging (MRI) . The subjects were five healthy untrained women (HUW) without lower back pain syndrome, and five Japanese female elite judo athletes (EJA) . There was no significant difference in height or weight between the HUW and EJA. Three-dimensional imaging of the LD and ES was reconstructed visually, based on MRI consecutive slice data taken from the first thoracic vertebra to the symphysis pubis along the trunk. Then the volume of the LD and ES was determined using a surface reconstruction algorithm.<BR>The morphological characteristics of the LD in the EJA appeared to indicate enlargment compared with those in the HUW, whereas the characteristics of the ES in both groups were similar. The volume of the LD was significantly different between the HUW (226.6±33.18 m<I>l</I>) and EJA (438.1±107.8 m<I>l</I>), whereas that of the ES showed no difference (HUW; 257.4±78.8 m<I>l</I>, EJA ; 284.0±74.82 m<I>l</I>) . In the EJA, but not in the HUW, there was a significant positive correlation between the volume of the LD and weight, and differences were noted between the two regression slopes. There was also a positive correlation between the volume of the ES and weight in both the HUW and EJA, which showed the same simple linear regression slope. These results suggest that the muscle hypertrophy evident in the LD, but not in the ES, is related to the effects of Judo training.

THREE DIMENSIONAL RECONSTRUCTION OF THIGH MUSCLE GROUPS BY COMPUTER GRAPHICS / 体力科学

The purpose of this study is to develop the non-invesive method for three dimensional analysis of knee extensor and knee flexor muscle groups of the thigh part in human subjects. Our system consisted of magnetic resonance imaging (MRI) to get cross-sectional images of muscle and a computer graphics system which reconstructs three dimensional image of each muscle. The subjects chosen for this study were four healthy male adults, aged from 21 to 30 years. MRI scan was carried out from head of the femur to the upper border of the patella along thigh. Three dimensional (3D) muscular image was reconstructed based on the data from MRI. Referring to the anatomic feature, contour information of knee extensor muscles (KEM) and knee flexor muscles (KFM) was identified on MRI and those muscles were reconstructed to 3 D images using the computer graphics system. This system also provided information on the quantitative volume and cross-sectional area (CSA) of each muscle.<BR>The structure of each muscle of KEM and KFM was displayed by a wireframe model or a surface model on the CRT. It was revealed that 3D muscular images of the surface model using coloring and shadowing were highly effective to understand their shapes and relative location of muscles. CSA and volume of KEM were 86.84±8.38cm<SUP>2</SUP>and 2044.25±168.28cm<SUP>3</SUP> and those of KFM were 38.48±5.90cm<SUP>2</SUP> and 751.95±50.56cm<SUP>3</SUP> respectively.<BR>These results indicate that not only the anatomical information but also the volume and maximum CSAs of KEM and KFM can be measured quantitatively by this method using three dimensional analysis.