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Background: Calcitonin gene-related peptide (CGRP) can protect against hyperoxia-induced lung injury, making the upregulation of CGRP a potential therapeutic approach for this type of injury. However, the effects of CGRP on the Wnt7b/β-catenin signaling pathway are unclear. In this study, we investigated the roles of CGRP and the Wnt7b/β-catenin signaling pathway in hyperoxia-induced lung injury. Methods: Premature Sprague Dawley (SD) rats were exposed to 21, 40, 60 and 95% oxygen for 3, 7 and 14 days. The animals’ body weights, survival rates and endogenous CGRP levels were measured. Lung samples were harvested for histological analyses and measurements of malondialdehyde (MDA) concentration and total antioxidant capacity (TAOC). We also assessed the MDA concentration and TAOC in the lung tissues after administration of 200 nmol/kg CGRP8–37 (a CGRP antagonist). Finally, alveolar epithelial type II (AEC II) cells were isolated from premature rats, exposed to 21 or 95% oxygen for 3, 7 and 14 days, and treated with 10− 8 mol/l exogenous CGRP. The protein expressions of Wnt7b and β-catenin were assessed using western blotting, and TCF and c-myc mRNA expressions were assessed using qPCR. Results: Rats exposed to 60 and 95% oxygen had significantly lower body weights and survival rates than the 21 and 40% groups, and the decrease was time dependent. Endogenous CGRP was elevated in the lung tissues of premature rats exposed to 95% oxygen. CGRP8–37 induced apparent inflammation in the lung tissue and alveolar structural remodeling. In addition, the expression levels of Wnt7b and β-catenin were markedly increased after exposure for 3 days. They peaked at 7 days, then declined at 14 days. The levels of TCF/c-myc in AEC II cells increased significantly after CGRP treatment when compared with cells that had only undergone hyperoxia. Conclusions: CGRP protected against hyperoxia-induced lung injury in premature rats. This process involves the Wnt7b/β-catenin signaling pathway.
Morphological traits of conifer species are known to vary adaptively with the geographic and climatic variables, but little is known about intra- and inter-population variation and impact of associated climate factors on the morphological variation. Chinese hard pine (Pinus tabulaeformis Carr) is a major and widespread component of coniferous forests in the temperate and semi-humid zone in northern China. Here we investigated 12 life history traits involving cone length (CL), width (CW) and dry weight (CDW), cone length to width ratio (CLW ), seed length (SL ), width (CW) and total weight (STW ), seed length to width ratio (SLW ), seed wing length (SWL), width (SWW) and total weight (SWTW ), seed wing length to width ration (SWLW ) at 12 sites between longitudes (102oE to 122oE) and latitudes (32oN to 43oN) covering an altitude range of 125–2581 m. Our results showed that each morphological character presented a large variation both within and among populations. Moreover, we found that proportion of phenotypic variation (i.e. Vst, %) of the all cone traits except for the cone width was over 50% among populations, indicating that the variation of these traits was mainly controlled by the environmental variables. Although the mean proportion of phenotypic variation of all measured traits was only about 28% among populations of this species, it was much higher than those of other conifers, which further suggested that this species held the higher adaptive phenotypic variation or stress-tolerance ability under varying environmental conditions. Furthermore, the phenotypic variation presented a general pattern that almost all measured traits were negatively correlated with the potential evapotranspiration which reflected the synthetic effects of multiple factors such as the temperature and rainfall, rather than a single environmental or climatic factor. In conclusion, according to the relationship between phenotypic variation and climate factors, it will undoubtedly provide important information for the reforestation and genetic conservation for this species in the changing climate.
Soil microorganisms play important roles in the dynamic regulation of organic matter in the forest ecosystem and are affected by different revegetation types. To reveal the influence of different revegetation types on soil microorganisms, we examined soil properties, soil microbial activity and diversity in Baishilazi Nature Reserve, including two planted coniferous forests (LG: Larix gmelinii, PK: Pinus koraiensis), two natural secondary broadleaf forests (JM: Juglans mandshurica, QM: Quercus mongolica), and one conifer-broadleaf forest (CB). Biolog-Eco plates were used to study soil microbial functional diversity. We found that the content of soil total C and total N existed higher under the broadleaf forests (JM, QM) than conifer-broadleaf forest (CB) and coniferous forests (LG, PK). Carbon source utilization capacity and soil microbial activity showed significant variations among different revegetation types. Soil microbial activity of natural secondary forests was significantly higher than planted coniferous forests, and JM created the highest soil microbial activity. Heatmap and PCA plot clearly differentiated among the different samples. The broadleaf forests, conifer-broadleaf forest and coniferous forests were well separated from each other, especially along the PC1, and the position of conifer-broadleaf forest was intermediate. The findings of canonical correspondence analysis (CCA) suggested that soil total C and total N were the main factors affecting soil microbial functional diversity. This study investigated how shifts in soil microbial functional diversity affected by different revegetation types were operational indicators of soil quality in Baishilazi Nature Reserve and that the JM created the highest carbon source utilization soil microbial diversity.
Human PCAN1 (prostate cancer gene 1) is a prostate-specific gene that is highly expressed in prostate epithelial tissue, and frequently mutated in prostate tumors. To better understand the regulation of the PCAN1 gene, a 2.6-kb fragment of its 5′ flanking region was obtained by PCR. Its promoter activity was examined via the dual-luciferase reporter assay after it had been cloned into a pGL3-basic vector generating pGL3-p2.6kb and transfected into LNCaP cells. pGL3-basic and pGL3-control were respectively used as the negative and positive controls. Sequence analysis with the MatInspector database showed that some possible binding sites for the transcriptional factors, NKX3.1, P53, SP1, cEBP and the PPAR/RXR heterodimers may locate on a 2.6-kb region upstream of the PCAN1 gene. To examine the relevant regulation of PCAN1, pGL3-p2.6kb was transfected into the prostate cancer cell line LNCaP, which was treated with R1881 (10−7∼10−9 mol/l), 17β-estradiol (17β-E2, 10−7∼10−9 mol/l), all-trans-retinoic acid (all-trans-RA, 10−5∼10−7 mol/l) or 9-cis-retinoic acid (9-cis-RA, 10−5∼10−7 mol/l), and eukaryotic expression plasmids of NKX3.1, p53, Sp1, Pten, PPARγ or cEBPα were cotransfected with pGL3-p2.6kb into LNCaP cells. pRL-TK, a Renilla luciferase reporter vector, was cotransfected into all the transfection lines as an internal control. The activities of pGL3-p2.6kb (PCAN1 promoter) were analyzed via the dual-luciferase reporter assay 48 h after transfection. The results showed that 9-cis-RA enhanced the PCAN1 promoter activity in a dose-dependent manner, while R1881, 17β-E2 and all-trans-RA had no significant effect on PCAN1 promoter activities. Cotransfection with pGL3-p2.6kb and the expression plasmids of NKX3.1, p53, Sp1 or Pten respectively resulted in 1.66-, 2.48-, 2.00-and 1.72-fold 2.6 kb PCAN1 promoter activity increases relative to the controls, which were cotransfected with pcDNA3.1(+), while cotransfection of PPARγ and cEBPα yielded no significant effect on PCAN1 promoter activities. These results could be applied for further study of the function and transcription regulation of the PCAN1 gene in prostate development and carcinogenesis.
Continuous rainfall during the harvest period of soybean leads to the delayed harvest of mature seeds and favors the infection of field mold that eventually causes seed mildew in the field under high humid conditions. Soybean isoflavones are a subgroup of flavonoids which possess crucial roles in the responses of soybean to multiple abiotic and/or biotic stresses. To fully reveal the role of isoflavones in the responses of soybean seeds to filed mildew (FM) stress, two soybean genotypes with different resistance to FM stress were treated in a controlled greenhouse which provided high humid conditions in this current research. The dynamic changes of isoflavones contents and the expression levels of four major genes involved in isoflavones biosynthesis pathway were measured by liquid chromatography–mass spectrometry (LC–MS) and quantitative real-time PCR (qRT-PCR), respectively. The current results showed that the contents of major isoflavones components in resistant genotype C103 were higher than the susceptive genotype ND12 before FM treatment. Whereas after FM treatment, the dynamic changing patterns of isoflavones contents and some major genes expression were opposite between these two genotypes, and the biosynthesis of isoflavones was more rapid in resistant genotype compared to susceptible one. Noticeably, the biosynthesis of isoflavones aglycones which exhibit better bioactivities was remarkably promoted after FM treatment in resistant genotype C103, further revealing the important role of isoflavones in the resistance against FM stress. In sum, this research investigated the role of isoflavones against FM stress, the results demonstrated higher inherent contents and more rapid biosynthesis of isoflavones after FM treatment could establish stronger resistant foundation in soybean seeds against the FM stress. These results would provide new insights into the mechanism research of soybean against FM stress, but how the stress systematically regulates isoflavones and other resistant network still needs further research.
Physiological and ecological adaptations of altitudinal gradients reveal alpine plants’ ecological and evolutionary responses to environmental changes. Here we quantitatively investigated the variation in the foliar physiological and morphological traits of alpine tree species (Abies fargesii) along the altitudinal gradient in the Taibai Mountains, China. We collected the needle samples of Taibai fir (A. fargesii) from seven sites at altitudes of 2550, 2650, 2750, 2850, 2950, 3050 and 3150 m, respectively, and measured the 12 foliar physiological and morphological traits. Each set of needle sample (100 needles) was randomly selected from the upper- third of A. fargesii canopies. The results showed that leaf mass per unit area (LMA), stable carbon isotope composition (δ13C), stomatal rows (SR), leaf carbon concentration per unit area (Carea), leaf nitrogen concentration per unit leaf mass (Nmass) and area (Narea) linearly increase significantly while stomatal density (SD), number of stomata per unit nitrogen concentration (St/N) and per unit leaf mass (St/LM) decrease with the altitudes raise. Moreover, all measured traits presented both strong correlations and significantly linear relationships with the main climate factors such as the mean temperature, rainfall and relative humidity during the growing season as well as the altitudes, except for leaf free water concentration (LWC), leaf carbon concentration per unit leaf mass (Cmass) and C: N ratio. The patterns of foliar traits in response to altitudes imply that the alpine plants need higher cost (e.g. higher nutrient concentration) to adapt to the harsher environments along altitudinal gradient. Moreover, our results show that the variation patterns of the leaf traits for A. fargesii plants should be driven by the interactions of multi-climate factors because the abiotic factors that directly influence the growth of plants covary with the increasing altitudes.
The macroscopic and microscopic morphologies and indigo and indirubin concen­tration of the traditional Chinese medicine herbs Isatis indigotica Fort., Polygonum tinctorium Ait., and Baphicacanthus cusia (Nees) Bremek, all commonly known as “daqingye”, were determined and compared. The morphological analyses indicated that I. indigotica has leaves with winged petioles and no glandular hairs or crystals, P. tinctorium has leaves with membranous ocrea and clusters of calcium oxalate, and B. cusia has palisade cells in the mesophyll running over the main vein and single cells containing calcium carbonate crystals. Indigo and indirubin are chemical constituents that have been previously isolated from daqingye and were selected in this study as identification markers for high-performance liquid chromatography analysis due to their pharmacological activities. The chromatographic results showed that indigo and indirubin concentration varied significantly among the three species: high concentration of both indigo and indirubin were observed in I. indigotica, the highest concentration among the three daqingye plants was found in P. tinctorium but with low levels of indirubin, and the concentration of indigo and indirubin was quite low in B. cusia. In summary, three different species commonly known as daqingye were accurately distinguished by morphological observation, internal leaf anatomy analysis, and chromatographic analysis.
Effect of altitude on leaf responses in Phleum himalaicum populations was evaluated at three different elevation levels, viz. (Low 1200 m.a.s.l.), middle (1600 m a.s.l.) and high (1900 m a.s.l.) in western part of Himalaya. We hypothesized that physico-chemical properties of soil varied along elevation and Phleum populations located at high elevation would adapt more distinct morphological and physiological traits than those originating from middle and low elevation sites. Our study revealed that soil pH, Ec Mg, Ca, and P decreased at high elevation however, significant increase was recorded in soil K, organic matter, and total nitrogen along the elevation gradient. A significant correlation between leaf characteristics and elevation sites was recorded along the gradient. The outcomes of this study showed that highland population had better adjustments under low temperature and exhibited adaptive traits. These were, decreased number of leaves and leaf area, increased leaf blade thickness, intensive sclerification, and greater stomatal and trichome density. Apart from these, high elevation population had more physiological adjustment in terms of low stomatal conductance, low transpiration rate, high water use efficiency, and synthesis of more osmolytes in leaf. We argued that certain level of sugar and protein must be attained by high population to dodge the aggressive climatic forces in order to grow successfully at the highest elevation. Furthermore, altitude between 1600 and 1900 m was more likely an optimum zone for vigorous growth of P. himalaicum at the highest level of elevation.
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