Sphingadienine-1-phosphate levels are regulated by a novel glycoside hydrolase family 1 glucocerebrosidase widely distributed in seed plants.

Long-chain base phosphates (LCBPs) such as sphingosine-1-phosphate and phytosphingosine-1-phosphate function as abscisic acid (ABA)-mediated signaling molecules that regulate stomatal closure in plants. Recently, a glycoside hydrolase family 1 (GH1) ß-glucosidase, Os3BGlu6, was found to improve drought tolerance by stomatal closure in rice, but the biochemical functions of Os3BGlu6 have remained unclear. Here we identified Os3BGlu6 as a novel GH1 glucocerebrosidase (GCase) that catalyzes the hydrolysis of glucosylceramide to ceramide. Phylogenetic and enzymatic analyses showed that GH1 GCases are widely distributed in seed plants and that pollen or anthers of all seed plants tested had high GCase activity, but activity was very low in ferns and mosses. Os3BGlu6 had high activity for glucosylceramides containing (4E,8Z)-sphingadienine, and GCase activity in leaves, stems, roots, pistils, and anthers of Os3BGlu6-deficient rice mutants was completely absent relative to that of wild-type rice. The levels of ceramides containing sphingadienine were correlated with GCase activity in each rice organ and were significantly lower in Os3BGlu6-deficient rice mutants than in the wild type. The levels of LCBPs synthesized from ceramides, especially the levels of sphingadienine-1-phosphate, were also correlated with GCase activity in each rice organ and were significantly lower in Os3BGlu6-deficient rice mutants than in the wild type. These results indicate that Os3BGlu6 regulates the level of ceramides containing sphingadienine, influencing the regulation of sphingadienine-1-phosphate levels and subsequent improvement of drought tolerance via stomatal closure in rice.

A new method for the preparation of a purified glucosylceramide and ceramide from shiitake mushroom.

Ingestion of plant and fungal glucosylceramides is known to reduce colon carcinogenesis and skin barrier damage in mice and humans. However, such effects in animal experiments have not been revealed for plant and fungal ceramides because the content of ceramides contained in plants and fungi is so low that the large amount required for animal experiments is difficult to obtain. Noting that the fungus shiitake mushroom (Lentinula edodes) is rich in a glucosylceramide, (4E,8E)-N-d-2'-hydroxypalmitoyl-1-O-ß-d-glucopyranosyl-9-methyl-4,8-sphingadienine [Glc-d19:2(4E,8E,9Me)-h16:0], we developed a new method to purify this fungal glucosylceramide using ethanol precipitation and high-performance liquid chromatography. We also developed a new method to produce large amounts of a ceramide [d19:2(4E,8E,9Me)-h16:0] from this purified glucosylceramide using human glycoside hydrolase family 30 glucocerebrosidase (imiglucerase). These methods will be useful for elucidating the physiological function by ingestion of fungal ceramides in animal experiments.

Performance of Forward Roll Maneuvers Following Corrective Spinal Fusion for Idiopathic Scoliosis Patients.

BACKGROUND: Fusion surgeries for scoliosis patients are believed to deteriorate sports performance; in particular, forward roll should deteriorate, but no literature is available to substantiate this claim. HYPOTHESIS: The extent of postoperative deterioration can vary according to surgery type or curve type. PATIENTS AND METHODS: Idiopathic scoliosis patients between 10 and 29 years of age who underwent correction and fusion surgeries at our hospital were included in this study. Forward roll was recorded on video preoperatively and 1-year postoperatively. Performances were evaluated twice on a 10-point scale by two blinded examiners. Preoperative and 1-year postoperative upright spinal radiographs were analyzed for the Lenke classification, number of fused vertebrae, upper and lower instrumented vertebrae, major curve Cobb angle, thoracic kyphosis, lumbar lordosis, and surgical procedures. RESULTS: The average age was 16 years. Curve types according to the Lenke classification were: 15, type 1; 5, type 2; 14, type 5; 2, type 6. The mean number of fused vertebrae was 6.9 (3.2 for anterior surgeries and 9.3 for posterior surgeries). The mean preoperative assessment of forward roll was 9.6 points, and the 1-year postoperative assessment was lower at 8.8 points. Cluster analysis classified patients into 3 groups: long fusion with marked performance deterioration (C1), long fusion with minimal deterioration (C2), and short fusion with minimal deterioration (C3). The upper and lower instrumented vertebrae in C1 were more distal than those in C2. CONCLUSION: Patients with thoracic curves were classified into two groups, and patients who underwent surgeries with more distal upper and lower instrumented vertebra levels exhibited lower postoperative performance. However, patients with Lenke 5 curves who underwent anterior surgery showed better preoperative performance than other patients who underwent posterior surgery, showing minimal postoperative deterioration. LEVEL OF EVIDENCE: III;Therapeutic Study.

The impact of self-efficacy for physical activity on health-related quality of life in total knee arthroplasty recipients.

BACKGROUND: Some patients with end-stage osteoarthritis of the knee remain unsatisfied after total knee arthroplasty (TKA). We postulated that to increase satisfaction, self-efficacy (SE) for physical activity should receive more attention in rehabilitative intervention, alongside the management of patient expectations, pain, and function. OBJECTIVE: We examined the relative impact of Physical Activity SE on Health-Related Quality of Life (HRQOL) alongside other factors such as pain and physical function which are well-addressed by current interventions. METHODS: One hundred and six first-TKA recipients (15 Male/91 Female, age 73.6 ± 7.2) were evaluated at 3 and 6 months post-operatively using the Medical Outcomes Study 36-Item Health Survey (SF-36v2) for HRQOL, knee extension strength measurement, Timed Up and Go test (TUG), One Leg Standing time test (OLS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for pain and function, and an instrument for measuring Physical Activity SE among the frail elderly in Japan. RESULTS: Significant improvement over pre-operative values was found at 3 and 6 months in TUG, OLS, WOMAC Pain and Function, and the 8 subscales of the SF-36v2. Factors found to significantly impact SF-36v2 subscale scores at 6 months post-operatively were found to be knee pain, knee function, and SE for physical activity. CONCLUSION: These results support our postulation that interventions to improve SE for physical activity could have comparable impact alongside interventions for knee pain and knee function, on the advancement of HRQOL among TKA recipients.