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81.
Salinity is a widespread environmental problem limiting productivity and growth of plants. Halophytes which can adapt and resist certain salt stress have various mechanisms to defend the higher salinity and alkalinity, and epigenetic mechanisms especially DNA methylation may play important roles in plant adaptability and plasticity. In this study, we aimed to investigate the different influences of various single salts (NaCl, Na2SO4, NaHCO3, Na2CO3) and their mixed salts on halophyte Chloris. virgata from the DNA methylation prospective, and discover the underlying relationships between specific DNA methylation variations and specific cations/anions through the methylation-sensitive amplification polymorphism analysis. The results showed that the effects on DNA methylation variations of single salts were ranked as follows: Na2CO3> NaHCO3> Na2SO4> NaCl, and their mixed salts exerted tissue-specific effects on C. virgata seedlings. Eight types of DNA methylation variations were detected and defined in C. virgata according to the specific cations/anions existed in stressful solutions; in addition, mix-specific and higher pH-specific bands were the main type in leaves and roots independently. These findings suggested that mixed salts were not the simple combination of single salts. Furthermore, not only single salts but also mixed salts showed tissue-specific and cations/anions-specific DNA methylation variations. 相似文献
82.
Guozheng Liu Dandan Cao Shuangshuang Li Aiguo Su Jianing Geng Corrinne E. Grover Songnian Hu Jinping Hua 《PloS one》2013,8(8)
Background
Mitochondria are the main manufacturers of cellular ATP in eukaryotes. The plant mitochondrial genome contains large number of foreign DNA and repeated sequences undergone frequently intramolecular recombination. Upland Cotton (Gossypium hirsutum L.) is one of the main natural fiber crops and also an important oil-producing plant in the world. Sequencing of the cotton mitochondrial (mt) genome could be helpful for the evolution research of plant mt genomes.Methodology/Principal Findings
We utilized 454 technology for sequencing and combined with Fosmid library of the Gossypium hirsutum mt genome screening and positive clones sequencing and conducted a series of evolutionary analysis on Cycas taitungensis and 24 angiosperms mt genomes. After data assembling and contigs joining, the complete mitochondrial genome sequence of G. hirsutum was obtained. The completed G.hirsutum mt genome is 621,884 bp in length, and contained 68 genes, including 35 protein genes, four rRNA genes and 29 tRNA genes. Five gene clusters are found conserved in all plant mt genomes; one and four clusters are specifically conserved in monocots and dicots, respectively. Homologous sequences are distributed along the plant mt genomes and species closely related share the most homologous sequences. For species that have both mt and chloroplast genome sequences available, we checked the location of cp-like migration and found several fragments closely linked with mitochondrial genes.Conclusion
The G. hirsutum mt genome possesses most of the common characters of higher plant mt genomes. The existence of syntenic gene clusters, as well as the conservation of some intergenic sequences and genic content among the plant mt genomes suggest that evolution of mt genomes is consistent with plant taxonomy but independent among different species. 相似文献83.
Zhenzhen Chen Shi Jia Danhua Li Junyan Cai Jian Tu Bin Geng Youfei Guan Qinghua Cui Jichun Yang 《PloS one》2013,8(11)
Recently, increasing evidences had suggested that long noncoding RNAs (LncRNAs) are involved in a wide range of physiological and pathophysiological processes. Here we determined the LncRNA expression profile using microarray technology in mouse livers after ischemia/reperfusion treatment. Seventy one LncRNAs were upregulated, and 27 LncRNAs were downregulated in ischemia/reperfusion-treated mouse livers. Eleven of the most significantly deregulated LncRNAs were further validated by quantitative PCR assays. Among the upregulated LncRNAs confirmed by quantitative PCR assays, AK139328 exhibited the highest expression level in normal mouse livers. siRNA-mediated knockdown of hepatic AK139328 decreased plasma aminotransferase activities, and reduced necrosis area in the livers with a decrease in caspase-3 activation after ischemia/reperfusion treatment. In ischemia/reperfusion liver, knockdown of AK139328 increased survival signaling proteins including phosphorylated Akt (pAkt), glycogen synthase kinase 3 (pGSK3) and endothelial nitric oxide synthase (peNOS). Furthermore, knockdown of AK139328 also reduced macrophage infitration and inhibited NF-κB activity and inflammatory cytokines expression. In conclusion, these findings revealed that deregulated LncRNAs are involved in liver ischemia/reperfusion injury. Silencing of AK139328 ameliorated ischemia/reperfusion injury in the liver with the activation of Akt signaling pathway and inhibition of NF-κB activity. LncRNA AK139328 might be a novel target for diagnosis and treatment of liver surgery or transplantation. 相似文献
84.
Background
Previous meta-analyses that compared the outcome of SILC and CLC have not presented consistent conclusions. This meta-analysis was performed after adding many recent RCTs, to clarify this issue.Methods
Relevant articles published in English were identified by searching PubMed, Embase, Web of Knowledge, and the Cochrane Controlled Trial Register from January 1997 to February 2013. Reference lists of the retrieved articles were reviewed to identify additional articles. Primary outcomes (postoperative pain scores, cosmetic score, and length of incision) and secondary outcomes (operating time, blood loss, conversion rates, postoperative complications, postoperative hospital stay, time to initial oral intake, and time to resume work) were pooled. Quantitative variables were calculated using the weighted mean difference (WMD), and qualitative variables were pooled using odds ratios (OR).Results
25 appropriate RCTs were identified from 2128 published articles. 1841 patients were treated, 944 with SILC and 897 with CLC. SILC was superior to CLC in cosmetic score (WMD = 1.155, P<0.001), shorter length of incision (WMD = -3.285, P = 0.029), and postoperative pain within 12 h (VAS in 3-4 h, WMD = -0.704, P = 0.026; VAS in 6-8 h, WMD = -0.613, P = 0.010). CLC was superior to SILC in operating time (OT) (WMD = 13.613, P<0.001) and need of additional instruments (OR = 7.448, P<0.001). Other secondary outcomes were similar.Conclusions
SILC offered a better cosmetic result and less postoperative pain for patients with uncomplicated cholelithiasis or polypoid lesions of the gallbladder. However, SILC was associated with a longer OT and required additional instruments. 相似文献85.
Li Wei Tao Xue Hong Yang Guang-Yue Zhao Geng Zhang Zhi-Hong Lu Yan-Hong Huang Xiang-Dong Ma Hai-Xia Liu Sheng-Ru Liang Fang Yang Bi-Liang Chen 《PloS one》2013,8(11)
Objective
To develop an orthotopic, allogeneic, uterine transplantation technique and an effective immunosuppressive protocol in the sheep model.Methods
In this pilot study, 10 sexually mature ewes were subjected to laparotomy and total abdominal hysterectomy with oophorectomy to procure uterus allografts. The cold ischemic time was 60 min. End-to-end vascular anastomosis was performed using continuous, non-interlocking sutures. Complete tissue reperfusion was achieved in all animals within 30 s after the vascular re-anastomosis, without any evidence of arterial or venous thrombosis. The immunosuppressive protocol consisted of tacrolimus, mycophenolate mofetil and methylprednisolone tablets. Graft viability was assessed by transrectal ultrasonography and second-look laparotomy at 2 and 4 weeks, respectively.Results
Viable uterine tissue and vascular patency were observed on transrectal ultrasonography and second-look laparotomy. Histological analysis of the graft tissue (performed in one ewe) revealed normal tissue architecture with a very subtle inflammatory reaction but no edema or stasis.Conclusion
We have developed a modified procedure that allowed us to successfully perform orthotopic, allogeneic, uterine transplantation in sheep, whose uterine and vascular anatomy (apart from the bicornuate uterus) is similar to the human anatomy, making the ovine model excellent for human uterine transplant research. 相似文献86.
Peter L. De Hoff Patrick Ferris Bradley J. S. C. Olson Ayano Miyagi Sa Geng James G. Umen 《PLoS genetics》2013,9(8)
Heteromorphic sex-determining regions or mating-type loci can contain large regions of non-recombining sequence where selection operates under different constraints than in freely recombining autosomal regions. Detailed studies of these non-recombining regions can provide insights into how genes are gained and lost, and how genetic isolation is maintained between mating haplotypes or sex chromosomes. The Chlamydomonas reinhardtii mating-type locus (MT) is a complex polygenic region characterized by sequence rearrangements and suppressed recombination between its two haplotypes, MT+ and MT−. We used new sequence information to redefine the genetic contents of MT and found repeated translocations from autosomes as well as sexually controlled expression patterns for several newly identified genes. We examined sequence diversity of MT genes from wild isolates of C. reinhardtii to investigate the impacts of recombination suppression. Our population data revealed two previously unreported types of genetic exchange in Chlamydomonas MT—gene conversion in the rearranged domains, and crossover exchanges in flanking domains—both of which contribute to maintenance of genetic homogeneity between haplotypes. To investigate the cause of blocked recombination in MT we assessed recombination rates in crosses where the parents were homozygous at MT. While normal recombination was restored in MT+×MT+ crosses, it was still suppressed in MT−×MT− crosses. These data revealed an underlying asymmetry in the two MT haplotypes and suggest that sequence rearrangements are insufficient to fully account for recombination suppression. Together our findings reveal new evolutionary dynamics for mating loci and have implications for the evolution of heteromorphic sex chromosomes and other non-recombining genomic regions. 相似文献
87.
Zhenqian Hu Yan Xiong Xiaofan Han Chenyang Geng Beibei Jiang Yingqing Huo Jincai Luo 《PloS one》2013,8(8)
In the vasculature, physiological levels of nitric oxide (NO) protect against various stressors, including mechanical stretch. While endothelial NO production in response to various stimuli has been studied extensively, the precise mechanism underlying stretch-induced NO production in venous endothelial cells remains incompletely understood. Using a model of continuous cellular stretch, we found that stretch promoted phosphorylation of endothelial NO synthase (eNOS) at Ser1177, Ser633 and Ser615 and NO production in human umbilical vein endothelial cells. Although stretch activated the kinases AMPKα, PKA, Akt, and ERK1/2, stretch-induced eNOS activation was only inhibited by kinase-specific inhibitors of PKA and PI3K/Akt, but not of AMPKα and Erk1/2. Similar results were obtained with knockdown by shRNAs targeting the PKA and Akt genes. Furthermore, inhibition of PKA preferentially attenuated eNOS activation in the early phase, while inhibition of the PI3K/Akt pathway reduced eNOS activation in the late phase, suggesting that the PKA and PI3K/Akt pathways play distinct roles in a time-dependent manner. Finally, we investigated the role of these pathways in stretch-induced endothelial exocytosis and leukocyte adhesion. Interestingly, we found that inhibition of the PI3K/Akt pathway increased stretch-induced Weibel-Palade body exocytosis and leukocyte adhesion, while inhibition of the PKA pathway had the opposite effects, suggesting that the exocytosis-promoting effect of PKA overwhelms the inhibitory effect of PKA-mediated NO production. Taken together, the results suggest that PKA and Akt are important regulators of eNOS activation in venous endothelial cells under mechanical stretch, while playing different roles in the regulation of stretch-induced endothelial exocytosis and leukocyte adhesion. 相似文献
88.
Ming Shan Xianyu Zhang Xiaolong Liu Yu Qin Tong Liu Yang Liu Ji Wang Zhenbin Zhong Youxue Zhang Jingshu Geng Da Pang 《PloS one》2013,8(10)
Breast cancers are heterogeneous and complex diseases, and subtypes of breast cancers may involve unique molecular mechanisms. The p16INK4a and p53 pathways are two of the major pathways involved in control of the cell cycle. They also play key roles in tumorigenesis. However, whether the roles of these pathways differ in the subtypes of breast cancer is unclear. Therefore, p16 and p53 expression were investigated in different breast cancer subtypes to ascertain their contributions to these cancers. A total of 400 cases of non-invasive ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC), including the major molecular subtypes luminal-A, luminal-B, Her-2, and triple-negative subtypes, and 50 cases of normal controls were compared. Luminal-A cancers expressed the lowest level of p16 among the subtypes in DCIS, and the level of p16 expression was up-regulated in the luminal-A of IDC (P<0.008). Triple-negative breast cancers were characterized by a correlation of p53 overexpression with a high level of p16 expression. Luminal lesion types with high p16 expression in DCIS were found to be more likely to develop into aggressive breast cancers, possibly promoted by p53 dysfunction. Taken together, the present study suggest that p16 expression in luminal-A breast cancers is associated with their progression from DCIS to IDC, and both p53 and p16 expressions are important for the development of triple-negative breast cancers in DCIS and IDC. 相似文献
89.
Lin Zhang Yaolin Song Lei Chen Donghang Li Haohao Feng Zilong Lu Tao Fan Zubin Chen Man J. Livingston Qing Geng 《Journal of cellular physiology》2020,235(4):3698-3710
Mesenchymal stem cells (MSCs) have been proved to exert considerable therapeutic effects on ischemia-reperfusion (I/R)-induced injury, but the underlying mechanism remains unknown. In this study, we aimed to explore the potential molecular mechanism underlying the therapeutic effect of MSCs-derived exosome reinforced with miR-20a in reversing liver I/R injury. Quantitative real-time polymerase chain reaction, Western blot, and IHC were carried out to compare the differential expressions of miR-20a, Beclin-I, FAS, Caspase-3, mTOR and P62 in IR rats and normal rats. TUNEL was performed to assess IR-induced apoptosis in IR rats, and luciferase assay was used to confirm the inhibitory effect of miR-20a on Beclin-I and FAS expression. Among the 12 candidate microRNAs (miRNAs), miR-486, miR-25, miR-24, miR-20a,miR-466 and miR-433-3p were significantly downregulated in I/R. In particular, miR-20a, a miRNA highly expressed in umbilical cord-derived mesenchymal stem cells, was proved to bind to the 3ʹ UTR of Beclin-I and FAS to exert an inhibitory effect on their expressions. Since Beclin-I and FAS were aberrantly upregulated in IR, exosomes separated from UC-MSCs showed therapeutic efficacy in reversing I/R induced apoptosis. In addition, exosomes reinforced with miR-20a and separated from UC-MSCs almost fully alleviated I/R injury. Furthermore, our results showed that miR-20a could alleviate the abnormal expression of genes related to apoptosis and autophagy, such as active Caspase-3, mTOR, P62, and LC3II. This study presented detailed evidence to clarify the mechanism underlying the therapeutic efficacy of UC-MSCs in the treatment of I/R injury. 相似文献
90.
Jiawei Shi Zhen Wang Xiaobin Guo Jining Shen Houyi Sun Jiaxiang Bai Binqing Yu Liangliang Wang Wei Zhou Yu Liu Wen Zhang Huilin Yang Yaozeng Xu Jun Zhou Dechun Geng 《Journal of cellular physiology》2020,235(3):2599-2608
Excessive osteoclast recruitment and activation is the chief cause of periprosthetic osteolysis and subsequent aseptic loosening, so blocking osteolysis may be useful for protecting against osteoclastic bone resorption. We studied the effect of aspirin on titanium (Ti)-particle-induced osteolysis in vivo and in vitro using male C57BL/6J mice randomized to sham (sham surgery), Ti (Ti particles), low-dose aspirin (Ti/5 mg·kg−1·d−1 aspirin), and high-dose aspirin (Ti/30 mg·kg−1·d−1 aspirin). After 2 weeks, a three-dimensional reconstruction evaluation using micro-computed tomography and histomorphology assessment were performed on murine calvariae. Murine hematopoietic macrophages and RAW264.7 lineage cells were studied to investigate osteoclast formation and function. Aspirin attenuated Ti-particle-induced bone erosion and reduced osteoclasts. In vitro, aspirin suppressed osteoclast formation, osteoclastic-related gene expression, and osteoclastic bone erosion in a dose-dependent manner. Mechanically, aspirin reduced osteoclast formation by suppressing receptor activator of nuclear factor kappa-B ligand-induced activation of extracellular signal-related kinase, p-38 mitogen-activated protein kinase, and c-Jun N-terminal kinase. Thus, aspirin may be a promising option for preventing and curing osteoclastic bone destruction, including peri-implant osteolysis. 相似文献