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31.
Norihiko Furuya Shin-Ichi Ikeda Shigeto Sato Sanae Soma Junji Ezaki Juan Alejandro Oliva Trejo Mitsue Takeda-Ezaki Tsutomu Fujimura Eri Arikawa-Hirasawa Norihiro Tada Masaaki Komatsu Keiji Tanaka Eiki Kominami Nobutaka Hattori Takashi Ueno 《Autophagy》2014,10(4):631-641
Skeletal muscle atrophy is thought to result from hyperactivation of intracellular protein degradation pathways, including autophagy and the ubiquitin–proteasome system. However, the precise contributions of these pathways to muscle atrophy are unclear. Here, we show that an autophagy deficiency in denervated slow-twitch soleus muscles delayed skeletal muscle atrophy, reduced mitochondrial activity, and induced oxidative stress and accumulation of PARK2/Parkin, which participates in mitochondrial quality control (PARK2-mediated mitophagy), in mitochondria. Soleus muscles from denervated Park2 knockout mice also showed resistance to denervation, reduced mitochondrial activities, and increased oxidative stress. In both autophagy-deficient and Park2-deficient soleus muscles, denervation caused the accumulation of polyubiquitinated proteins. Denervation induced proteasomal activation via NFE2L1 nuclear translocation in control mice, whereas it had little effect in autophagy-deficient and Park2-deficient mice. These results suggest that PARK2-mediated mitophagy plays an essential role in the activation of proteasomes during denervation atrophy in slow-twitch muscles. 相似文献
32.
Kenichi?MeguroEmail author Yoshitaka?Ouchi Kyoko?Akanuma Mitsue?Meguro Mari?Kasai 《BMC neurology》2014,14(1):243
Background
Cholinesterase inhibitors can delay the progression of Alzheimer’s disease (AD). Several clinical trials of the drug in moderate to severe AD have consistently reported clinically positive effects. A combining effect with psychosocial intervention was reported in mild to moderate AD patients. Since a therapeutic approach or rehabilitation combined with cholinesterase inhibitors for severe AD patients remains controversial, we performed a prospective intervention for patients in Long-Term Care Health Facilities (LTCHF).Methods
Two LTCHFs (N1, N2) were enrolled. N1 is a 126-bed facility that does not treat with donepezil but rather with psychosocial intervention (reality orientation and reminiscence). N2 is a 150-bed facility with a 50-bed special dementia unit, in which the physician can prescribe donepezil. On top of the similar psychosocial intervention, rehabilitation is performed in N2. Thirty-two severe AD patients (MMSE <?6) in N1 and N2 (16 vs. 16) were compared for the effect of donepezil (10 mg/d for 3 months) with or without psychosocial intervention (n =?8 vs. 8 for each facility). The Vitality Index was used to assess daily activities and the introduction of rehabilitation.Results
The response ratio (MMSE 3+) of donepezil was 37.5% in N2. The combination of donepezil with the psychosocial intervention improved the Vitality Index total score, and Communication, Eating, and Rehabilitation subscores (Wilcoxon, p =?0.016, 0.038, 0.023, and 0.011, respectively). Most of them were smoothly introduced to rehabilitation, and the proportion of accidental falls decreased. Psychosocial intervention in N1 without the drug only improved the total score (Wilcoxon, p =?0.046).Conclusions
A combined therapeutic approach of donepezil and psychosocial intervention can have a positive effect, even for severe patients through the introduction of rehabilitation and decreasing accidental falls. However, these findings require replication in a larger cohort.33.
Nomura M Katayama K Nishimura A Ishida Y Ohta S Komari T Miyao-Tokutomi M Tajima S Matsuoka M 《Plant molecular biology》2000,44(1):99-106
The small subunit of ribulose-bisphosphate carboxylase (Rubisco), encoded by rbcS, is essential for photosynthesis in both C3 and C4 plants, even though the cell specificity of rbcS expression is different between C3 and C4 plants. The C3 rbcS is specifically expressed in mesophyll cells, while the C4 rbcS is expressed in bundle sheath cells, and not mesophyll cells. Two chimeric genes were constructed consisting of the structural gene encoding -glucuronidase (GUS) controlled by the two promoters from maize (C4) and rice (C3) rbcS genes. These constructs were introduced into a C4 plant, maize. Both chimeric genes were specifically expressed in photosynthetic organs, such as leaf blade, but not in non-photosynthetic organs. The expressions of the genes were also regulated by light. However, the rice promoter drove the GUS activity mainly in mesophyll cells and relatively low in bundle sheath cells, while the maize rbcS promoter induced the activity specifically in bundle sheath cells. These results suggest that the rice promoter contains some cis-acting elements responding in an organ-pecific and light-inducible regulation manner in maize but does not contain element(s) for bundle sheath cell-specific expression, while the maize promoter does contain such element(s). Based on this result, we discuss the similarities and differences between the rice (C3) and maize (C4) rbcS promoter in terms of the evolution of the C4 photosynthetic gene. 相似文献
34.
Mitsue Shibata Satoshi Kikuchi Hiroshi Tanaka Masahiro Sueyoshi Hiroshi Yoshimaru Kaoru Niiyama 《Ecological Research》2009,24(1):1-9
The effects of local population density, sex morph [protogynous (PG) or protandrous (PA)], and individual tree size on the
demographic processes of seed production were investigated in a heterodichogamous maple, Acer mono Maxim. var. Marmoratum (Nichols.) Hara f. dissectum, in a temperate forest of Japan. As the distance from conspecific reproductive adults increased, the percentage of immature
seed fall and empty seeds increased significantly, indicating higher pollination success along with local population density.
Although the difference was not distinct, pollination success was affected by the local population density of the reciprocal
sex morph rather than that of both sex morphs. The trees at higher local population density sites suffered higher seed mortality
due to predation and decay, and tended to produce smaller seeds. Thus, the impacts of local population density operated both
positively and negatively on reproduction. As a factor of individual traits, tree size scarcely affected any demographic processes.
On the other hand, sex morph did affect pollination success. Trees of PG type had lower immature seed fall than those of PA
type, suggesting that the former has higher efficiency of pollen acceptance than the latter. The results on seed demography
presented here partly support previous suggestions that heterodichogamous plants exhibit reciprocal cross-pollination and
gender specialization as reproductive traits. 相似文献
35.
Toshiaki Gunji Nobuyuki Matsuhashi Hajime Sato Kazutoshi Fujibayashi Mitsue Okumura Noriko Sasabe Akio Urabe 《Helicobacter》2009,14(5):496-502
Background: Helicobacter pylori infection has been shown to contribute to atherosclerosis and cardiovascular diseases. Insulin resistance is the pathophysiologic background of the clinical features of atherosclerosis and cardiovascular diseases. We examined the association between H. pylori infection and insulin resistance in a large Japanese population. Materials and Methods: Fifteen hundred ninety‐eight consecutive asymptomatic subjects that underwent a complete medical survey in our institute between May 2007 and July 2008 were recruited. Cases under medication for hypertension, hyperlipidemia, diabetes mellitus, hyperuricemia, or cardiovascular diseases were excluded from the study. Cases suffering from chronic renal or liver failure were also excluded. The homeostasis model assessment of insulin resistance (HOMA‐IR) score was used to quantitatively estimate insulin resistance. Visceral and subcutaneous adipose tissues (SAT) were measured by computed tomography. The association between H. pylori serostatus and HOMA‐IR score was investigated by multivariate regression analysis. Results: A total of 988 men and 119 women were eventually eligible for this cross‐sectional survey. Helicobacter pylori seropositivity was significantly higher in 99 cases with insulin resistance (HOMA‐IR ≥2.5) compared with 1008 cases without insulin resistance (HOMA‐IR <2.5) (39.4 vs 28.7%, p = .027). There was a significant association between H. pylori serostatus and HOMA‐IR score by multiple linear regression analysis (coefficients = 0.152, 95% CI = 0.058–0.246, p = .001), after adjusting for sex, age, body mass index, waist girth, visceral and subcutaneous adipose tissues, smoking status, alcohol consumption, dietary habits, and physical activity. Conclusions: Helicobacter pylori infection significantly and independently contributed to promoting insulin resistance in a large asymptomatic population. 相似文献
36.
Chymotrypsin eliminated nine amino acid residues at the amino-terminal side of the extrinsic 23-kDa protein of the oxygen-evolving Photosystem II complex of spinach. The resultant 22-kDa fragment was able to bind to the Photosystem II complex but with lowered binding affinity. However, once the 22-kDa fragment bound to the complex, it retained most functions of the 23-kDa protein; the fragment provided a binding site for the extrinsic 18-kDa protein, preserved a tight trap for Ca2+ in the complex, and shifted the optimum Cl− concentration for oxygen evolution from 30 to 10 mM, although it was less effective in sustaining oxygen evolution at Cl− concentrations below 10 mM. These observations suggest that the elimination of nine amino acid residues at the amino-terminal region of the 23-kDa protein does not significantly alter the conformation of the protein, except for partial modification of its binding site and its interaction with Cl−. 相似文献
37.
Gabriela B. Cybis Gislene L. Gonçalves Alcides Pissinatti Francisco M. Salzano Maria Cátira Bortolini 《Journal of evolutionary biology》2018,31(8):1180-1192
Traits that undergo massive natural selection pressure, with multiple events of positive selection, are hard to find. Social behaviour, in social animals, is crucial for survival, and genetic networks involved in behaviour, such as those of serotonin (5‐HT) and other neurotransmitters, must be the target of natural selection. Here, we used molecular analyses to search for signals of positive selection in the 5‐HT system and found such signals in the M3‐M4 intracellular domain of the 5‐HT3A serotonin receptor subunit (HTR3A) in primates. We detected four amino acid sites with signs of putatively positive selection (398, 403, 432 and 416); the first three showed indications of being selected in New World monkeys (NWM, Platyrrhini), specifically in the Callitrichinae branch. Additionally, we searched for associations of these amino acid variants with social behavioural traits (i.e. sex‐biased dispersal, dominance and social monogamy) using classical and Bayesian methods, and found statistically significant associations for unbiased sex dispersal (398L and 416S), unbiased sex dominance (416S) and social monogamy (416S), as well as significant positive correlation between female dispersal and 403G. Furthermore, we found putatively functional protein motifs determined by three selected sites, of which we highlight a ligand motif to GSK3 in the 416S variant, appearing only in Platyrrhini. 5‐HT, 5‐HT3A receptor and GSK3 are part of a network that participates in neurodevelopment and regulates behaviour, among other functions. We suggest that these genetic variations, together with those found in other neurotransmitter systems, must contribute to adaptive behaviours and consequently to fitness in NWMs. 相似文献
38.
Subtle variation in size and shape of the whole forewing and the red band among co‐mimics revealed by geometric morphometric analysis in Heliconius butterflies
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Dirleane O. Rossato Danessa Boligon Rodrigo Fornel Marcus R. Kronforst Gislene L. Gonçalves Gilson R. P. Moreira 《Ecology and evolution》2018,8(6):3280-3295
Heliconius are unpalatable butterflies that exhibit remarkable intra‐ and interspecific variation in wing color pattern, specifically warning coloration. Species that have converged on the same pattern are often clustered in Müllerian mimicry rings. Overall, wing color patterns are nearly identical among co‐mimics. However, fine‐scale differences exist, indicating that factors in addition to natural selection may underlie wing phenotype. Here, we investigate differences in shape and size of the forewing and the red band in the Heliconius postman mimicry ring (H. erato phyllis and the co‐mimics H. besckei, H. melpomene burchelli, and H. melpomene nanna) using a landmark‐based approach. If phenotypic evolution is driven entirely by predation pressure, we expect nonsignificant differences among co‐mimics in terms of wing shape. Also, a reinforcement of wing pattern (i.e., greater similarity) could occur when co‐mimics are in sympatry. We also examined variation in the red forewing band because this trait is critical for both mimicry and sexual communication. Morphometric results revealed significant but small differences among species, particularly in the shape of the forewing of co‐mimics. Although we did not observe greater similarity when co‐mimics were in sympatry, nearly identical patterns provided evidence of convergence for mimicry. In contrast, mimetic pairs could be distinguished based on the shape (but not the size) of the red band, suggesting an “advergence” process. In addition, sexual dimorphism in the red band shape (but not size) was found for all lineages. Thus, we infer that natural selection due to predation by birds might not be the only mechanism responsible for variation in color patterns, and sexual selection could be an important driver of wing phenotypic evolution in this mimicry ring. 相似文献
39.
Iliane Freitas de Souza Alexandre F. Souza Marco Aurélio Pizo Gislene Ganade 《Biodiversity and Conservation》2010,19(6):1683-1698
To evaluate the effects of distinct management of the matrix in which forest fragments are found upon plant populations thriving
in forest remnants in south Brazil, we assessed the conservation status of populations of four woody species (Campomanesia rhombea, Diospyros incontans, Myrciaria cuspidata and Sebastiania commersoniana) through analyses of size structure. Analyzes were carried out at two scales. At a local scale, we consider populations in
fragments surrounded by pastures or eucalypts forest plantations, and at a regional scale we also consider larger forest tracts
taken as reference areas (Rio Grande do Sul Forest Inventory databank). Population size structures were summarized using the
symmetry of height distributions. Small individual size classes prevailed at the local scale in fragments surrounded by eucalypts
plantations, whereas in areas exposed to cattle ranching, populations of the same species consistently lack small individuals.
At the regional scale, populations in fragments surrounded by pastures presented greater skewness (prevalence of small plants)
than populations in reference areas, while populations surrounded by eucalypts plantations presented intermediate skewness.
These results reinforce the notion that plantations have a higher conservation value for forest ecosystems than other commercial
land uses, like cattle ranching. 相似文献
40.
The asymmetrically dividing budding yeast relies upon the alignment of the mitotic spindle along the mother to daughter cell polarity axis for the fidelity of chromosome segregation during mitosis. In the case of spindle misalignment, a surveillance mechanism named the spindle position checkpoint (SPOC) prevents cells from exiting mitosis through the inhibition of the mitotic exit network (MEN). MEN is a signal transduction pathway that mediates mitotic exit through fully activation of the Cdk-counteracting phosphatase Cdc14. In this mini-review, we briefly describe the mechanisms leading to mitotic exit in budding yeast cells focusing on the control of MEN by the SPOC. In addition, we summarize the recent advances in the molecular understanding of SPOC regulation and discuss whether similar checkpoints may exist in higher eukaryotic cells that undergo asymmetric divisions. 相似文献