Hisato Shuntoh

Zinc Finger Protein Prz1 Regulates Ca2+ but Not Cl− Homeostasis in Fission Yeast IDENTIFICATION OF DISTINCT BRANCHES OF CALCINEURIN SIGNALING PATHWAY IN FISSION YEAST

Calcineurin is an important mediator that connects the Ca2+-dependent signaling to various cellular responses in a wide variety of cell types and organisms. In budding yeast, activated calcineurin exerts its function mainly by regulating the Crz1p/Tcn1 transcription factor. Here, we cloned the fission yeast prz1 + gene, which encodes a zinc finger transcription factor highly homologous to Crz1/Tcn1. Similar to the results in budding yeast, calcineurin dephosphorylated Prz1 and resulted in the trans-location of Prz1 from the cytoplasm to the nucleus. Prz1 expression was stimulated by high extracellular Ca2+ in a calcineurin-dependent fashion. However, unlike in budding yeast, the prz1-null cells did not show any phenotype similar to those previously reported in calcineurin deletion such as aberrant cell morphology, mating defect, or hypersensitivity to Cl−. Instead, theprz1-null cells showed hypersensitivity to Ca2+, consistent with a dramatic decrease in transcription of Pmc1 Ca2+ pump. Interestingly, overexpression of Prz1 did not suppress the Cl− hypersensitivity of calcineurin deletion, and overexpression of Pmp1 MAPK phosphatase suppressed the Cl− hypersensitivity of calcineurin deletion but not the Ca2+ hypersensitivity of prz1 deletion. In addition, mutations in theits2 + /cps1 + ,its8 + , andits10 + /cdc7 + genes that showed synthetic lethal genetic interaction with calcineurin deletion did not exhibit synthetic lethality with the prz1 deletion. Our results suggest that calcineurin activates at least two distinct signaling branches, i.e. the Prz1-dependent transcriptional regulation and an unknown mechanism, which functions antagonistically with the Pmk1 MAPK pathway.

Genetic and functional interaction between Ryh1 and Ypt3: two Rab GTPases that function in S. pombe secretory pathway

We have previously isolated ypt3‐i5 mutant and showed that Ypt3 GTPase functions in the fission yeast secretory pathway. Here, the same genetic screen led to the isolation of ryh1‐i6, a mutant allele of the ryh1+ gene encoding a homolog of Rab6. The ryh1‐i6 mutant showed phenotypes that support its role in retrograde traffic from endosome to the Golgi. Interestingly, ryh1+ gene deletion was synthetically lethal with ypt3‐i5 mutation. Consistently, the over‐expression of the GDP‐conformational mutant, Ryh1T25 N, inhibited the growth of ypt3‐i5 mutant but had no effect on that of wild‐type cells. Furthermore, the over‐expression of the Ryh1T25N mutant inhibited the acid phosphatase glycosylation and exacerbated the cell wall integrity of ypt3‐i5 mutant, but had no effect on those of wild‐type cells. GFP‐Ryh1 and GFP‐Ypt3 both localized at the Golgi/endosome, but showed distinct subcellular localizations. The localization of GFP‐Ryh1 in ypt3‐i5 mutant and that of GFP‐Ypt3 in ryh1‐i6 mutant were distinct from those in wild‐type cells. In addition, Ryh1 as well as Ypt3 were shown to be involved in acid phosphatase secretion. These results suggest that Ryh1 is involved in the secretory pathway and may have a potential overlapping function with Ypt3 in addition to its role in recycling.

Effect of a postoperative outpatient pulmonary rehabilitation program on physical activity in patients who underwent pulmonary resection for lung cancer

Physical activity (PA) has been associated with an improvement in survival for individuals with cancer. However, little is known about the effect of postoperative pulmonary rehabilitation on PA after lobectomy in patients with lung cancer. The present study investigated the effect of outpatient rehabilitation on PA in patients with cancer after lung resection.

Effect of expiratory resistive loading in expiratory muscle strength training on orbicularis oris muscle activity.

[Purpose] The purpose of this study was to elucidate the effect of expiratory resistive loading on orbicularis oris muscle activity. [Subjects] Subjects were 23 healthy individuals (11 males, mean age 25.5±4.3 years; 12 females, mean age 25.0±3.0 years). [Methods] Surface electromyography was performed to measure the activity of the orbicularis oris muscle during maximum lip closure and resistive loading at different expiratory pressures. Measurement was performed at 10%, 30%, 50%, and 100% of maximum expiratory pressure (MEP) for all subjects. The t-test was used to compare muscle activity between maximum lip closure and 100% MEP, and analysis of variance followed by multiple comparisons was used to compare the muscle activities observed at different expiratory pressures. [Results] No significant difference in muscle activity was observed between maximum lip closure and 100% MEP. Analysis of variance with multiple comparisons revealed significant differences among the different expiratory pressures. [Conclusion] Orbicularis oris muscle activity increased with increasing expiratory resistive loading.

Change in tongue morphology in response to expiratory resistance loading investigated by magnetic resonance imaging.

[Purpose] The purpose of this study was to investigate the effect of expiratory resistance load on the tongue area encompassing the suprahyoid and genioglossus muscles. [Subjects] The subjects were 30 healthy individuals (15 males, 15 females, mean age: 28.9 years). [Methods] Magnetic resonance imaging was used to investigate morphological changes in response to resistive expiratory pressure loading in the area encompassing the suprahyoid and genioglossus muscles. Images were taken when water pressure was sustained at 0%, 10%, 30%, and 50% of maximum resistive expiratory pressure. We then measured tongue area using image analysis software, and the morphological changes were analyzed using repeated measures analysis of variance followed by post hoc comparisons. [Results] A significant change in the tongue area was detected in both sexes upon loading. Multiple comparison analysis revealed further significant differences in tongue area as well as changes in tongue area in response to the different expiratory pressures. [Conclusion] The findings demonstrate that higher expiratory pressure facilitates greater reduction in tongue area.

Muscle Thickness and Echo Intensity of the Abdominal and Lower Extremity Muscles in Stroke Survivors

Background and Purpose This study compared the muscle thickness (MT) and echo intensity (EI) of the abdominal, thigh, and lower leg muscles between the paretic and nonparetic sides in chronic stroke survivors. Methods Thirty-two stroke survivors living in the community participated in this study. The MT and EI, which are indicators of muscle mass and intramuscular fat or connective tissue, were assessed in the rectus abdominis, external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, tibialis anterior, gastrocnemius, and soleus via transverse ultrasound imaging. In addition, a possible indicator of physical activity—the frequency of going out per week—was evaluated. Results All quadriceps muscles and the tibialis anterior were significantly thinner and the EI values of the vastus intermedius, vastus lateralis, vastus medialis, and soleus were significantly higher in the paretic limb than the nonparetic limb. The MT and EI values of abdominal muscles did not differ significantly between the two sides. The MT values of the paretic rectus femoris, vastus lateralis, and vastus medialis were significantly associated with the frequency of going out after adjusting confounding factors. The MT of the nonparetic vastus lateralis was significantly associated with latency from stroke onset after adjusting confounding factors. Conclusions Our results indicate that quantitative and qualitative changes on the paretic side in stroke survivors were the most robust in the thigh muscles, whereas such changes might not occur in the abdominal muscles.