慢性肾脏病-矿物质和骨代谢异常(chronic kidney disease-mineral and bone disorder,CKD-MBD)是慢性肾脏病(chronic kidney disease,CKD)患者常见的并发症之一,控制高磷血症为防治CKD-MBD的关键。然而,药物作为慢性肾脏病患者磷肠道负...慢性肾脏病-矿物质和骨代谢异常(chronic kidney disease-mineral and bone disorder,CKD-MBD)是慢性肾脏病(chronic kidney disease,CKD)患者常见的并发症之一,控制高磷血症为防治CKD-MBD的关键。然而,药物作为慢性肾脏病患者磷肠道负荷的潜在来源却常常被忽视。故本文针对药物的磷含量、低磷/蛋白质比值饮食的研究进展予以综述。展开更多
The effects of individual and combined additions of urea (100 μg N g-1 soil) and insecticide (triazophos at field rate, FR) under different moisture levels of air-dried soil (AD), 50% of water-holding capacity (WHC),...The effects of individual and combined additions of urea (100 μg N g-1 soil) and insecticide (triazophos at field rate, FR) under different moisture levels of air-dried soil (AD), 50% of water-holding capacity (WHC), 100% WHC and flooded soil (FS) on some selected soil properties in a paddy field soil were examined in a laboratory incubation study. The results indicated that after 21-day incubation at 25℃, the different moisture levels led to significant changes in the parameters studied. Flooding of soil with distilled water significantly increased the electron transport system (ETS) /dehydrogenase activity and phenol contents of the soil compared to the other moisture levels, while protein and phospholipids behaved differently at varied moisture levels with or without the addition of urea and/or triazophos. Increased ETS activity was observed with N addition at higher moisture levels while insecticide incorporation decreased it at all moisture levels as compared to the control (moisture only). The phenol contents slightly decreased and increased with N and insecticide applications, respectively. The soil protein contents were found to be unaffected among all the soil treatments at all moisture levels. However, among different moisture levels, reduced quantities of proteins were estimated at 50% WHC, suggesting more N-mineralization. Lower quantities of soil biomass phospholipids, among all treatments, were recorded at higher moisture levels (100% WHC and FS) than at the lower levels. An overall slight enhancement in phospholipid contents with N and small reduction with insecticide addition, respectively, was noticed against the untreated soil. The toxicity of fertilizer and insecticide decreased as the soil moisture contents increased, suggesting rapid degradation of agrochemicals.展开更多
AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression...AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.展开更多
The most striking morphological feature of eukaryotic cells is the presence of various membrane-enclosed compartments. These compartments, including organelles and transient transport intermediates, are not static. Ra...The most striking morphological feature of eukaryotic cells is the presence of various membrane-enclosed compartments. These compartments, including organelles and transient transport intermediates, are not static. Rather, dynamic exchange of proteins and membrane is needed to maintain cellular homeostasis. One of the most dramatic examples of membrane mobilization is seen during the process ofmacroautophagy. Macroautophagy is the primary cellular pathway for degradation of long-lived proteins and organelles. In response to environmental cues, such as starvation or other types of stress, the cell produces a unique membrane structure, the phagophore. The phagophore sequesters cytoplasm as it forms a double-membrane cytosolic vesicle, an autophagosome. Upon completion, the autophagosome fuses with a lysosome or a vacuole in yeast, which delivers hydrolases that break down the inner autophagosome membrane along with its cargo, and the resulting macromolecules are released back into the cytosol for reuse. Autophagy is therefore a recycling process, allowing cells to survive periods of nutrient limitation; however, it has a wider physiological role, participating in development and aging, and also in protection against pathogen invasion, cancer and certain neurodegenerative diseases. In many cases, the role ofautophagy is identified through studies of an autophagy-related protein, Atg6/Beclin 1. This protein is part of a lipid kinase complex, and recent studies suggest that it plays a central role in coordinating the cytoprotective function ofautophagy and in opposing the cellular death process of apoptosis. Here, we summarize our current knowledge ofAtg6/Beclin 1 in different model organisms and its unique function in the cell.展开更多
Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 ...Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 （PP1） is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase l（PPlcb）, was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPPlcb, by the rapid amplification of cDNA ends （RACE） technique. The cDNA sequence of SmPPlcb we obtained contains a 984 bp open reading frame （ORF）, flanked by a complete 39 bp 5＇ untranslated region and 462 bp 3＇ untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B （PP2B）. And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPPlcb is extremely conserved in both amino acid and nucleotide acid levels compared with the PPlcb of other vertebrates and invertebrates, and its Kozak motif contained in the 5＇UTR around ATG start codon is GXXAXXGXXATGG, which is different from mammalian in two positions A6 and G3, indicating the possibility of different initiation of translation in turbot, and also the 3＇UTR of SmPPlcb is highly diverse in the sequence similarity and length compared with other animals, especially zebraf＇lsh. The cloning and sequencing of SmPPlcb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.展开更多
Glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. H...Glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. However, emerging evidence indicates that GAPDH is implicated in diverse functions independent of its role in energy metabolism; the expression status of GAPDH is also deregulated in various cancer cells. One of the most common effects of GAPDH is its inconsistent role in the determination of cancer cell fate. Furthermore, studies have described GAPDH as a regulator of cell death; other studies have suggested that GAPDH participates in tumor progression and serves as a new therapeutic target. However, related regulatory mechanisms of its numerous cellular functions and deregulated expression levels remain unclear. GAPDH is tightly regulated at transcriptional and pnsttranscriptional levels, which are involved in the regulation of diverse GAPDH functions. Several cancer-related factors, such as insulin, hypoxia inducible factor-1 （HIF-1）, p53, nitric oxide （NO）, and acetylated histone, not only modulate GAPDH gene expression but also affect protein functions via common pathways. Moreover, posttranslational modifications （PTMs） occurring in GAPDH in cancer cells result in new activities unrelated to the original glycnlytic function of GAPDH. In this review, recent findings related to GAPDH transcriptional regulation and PTMs are summarized. Mechanisms and pathways involved in GAPDH regulation and its different roles in cancer cells are also described.展开更多
The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to s...The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.展开更多
文摘慢性肾脏病-矿物质和骨代谢异常(chronic kidney disease-mineral and bone disorder,CKD-MBD)是慢性肾脏病(chronic kidney disease,CKD)患者常见的并发症之一,控制高磷血症为防治CKD-MBD的关键。然而,药物作为慢性肾脏病患者磷肠道负荷的潜在来源却常常被忽视。故本文针对药物的磷含量、低磷/蛋白质比值饮食的研究进展予以综述。
基金supported by the International Rice Research Institute (IRRI) under project of Reversing Trends of Declining Productivity (RTDP
文摘The effects of individual and combined additions of urea (100 μg N g-1 soil) and insecticide (triazophos at field rate, FR) under different moisture levels of air-dried soil (AD), 50% of water-holding capacity (WHC), 100% WHC and flooded soil (FS) on some selected soil properties in a paddy field soil were examined in a laboratory incubation study. The results indicated that after 21-day incubation at 25℃, the different moisture levels led to significant changes in the parameters studied. Flooding of soil with distilled water significantly increased the electron transport system (ETS) /dehydrogenase activity and phenol contents of the soil compared to the other moisture levels, while protein and phospholipids behaved differently at varied moisture levels with or without the addition of urea and/or triazophos. Increased ETS activity was observed with N addition at higher moisture levels while insecticide incorporation decreased it at all moisture levels as compared to the control (moisture only). The phenol contents slightly decreased and increased with N and insecticide applications, respectively. The soil protein contents were found to be unaffected among all the soil treatments at all moisture levels. However, among different moisture levels, reduced quantities of proteins were estimated at 50% WHC, suggesting more N-mineralization. Lower quantities of soil biomass phospholipids, among all treatments, were recorded at higher moisture levels (100% WHC and FS) than at the lower levels. An overall slight enhancement in phospholipid contents with N and small reduction with insecticide addition, respectively, was noticed against the untreated soil. The toxicity of fertilizer and insecticide decreased as the soil moisture contents increased, suggesting rapid degradation of agrochemicals.
基金Supported by National Natural Science Foundation of ChinaNo. 39670671, No. 30471531
文摘AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.
文摘The most striking morphological feature of eukaryotic cells is the presence of various membrane-enclosed compartments. These compartments, including organelles and transient transport intermediates, are not static. Rather, dynamic exchange of proteins and membrane is needed to maintain cellular homeostasis. One of the most dramatic examples of membrane mobilization is seen during the process ofmacroautophagy. Macroautophagy is the primary cellular pathway for degradation of long-lived proteins and organelles. In response to environmental cues, such as starvation or other types of stress, the cell produces a unique membrane structure, the phagophore. The phagophore sequesters cytoplasm as it forms a double-membrane cytosolic vesicle, an autophagosome. Upon completion, the autophagosome fuses with a lysosome or a vacuole in yeast, which delivers hydrolases that break down the inner autophagosome membrane along with its cargo, and the resulting macromolecules are released back into the cytosol for reuse. Autophagy is therefore a recycling process, allowing cells to survive periods of nutrient limitation; however, it has a wider physiological role, participating in development and aging, and also in protection against pathogen invasion, cancer and certain neurodegenerative diseases. In many cases, the role ofautophagy is identified through studies of an autophagy-related protein, Atg6/Beclin 1. This protein is part of a lipid kinase complex, and recent studies suggest that it plays a central role in coordinating the cytoprotective function ofautophagy and in opposing the cellular death process of apoptosis. Here, we summarize our current knowledge ofAtg6/Beclin 1 in different model organisms and its unique function in the cell.
基金Supported by the 863 Program of China (No. AA2001628130)
文摘Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 （PP1） is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase l（PPlcb）, was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPPlcb, by the rapid amplification of cDNA ends （RACE） technique. The cDNA sequence of SmPPlcb we obtained contains a 984 bp open reading frame （ORF）, flanked by a complete 39 bp 5＇ untranslated region and 462 bp 3＇ untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B （PP2B）. And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPPlcb is extremely conserved in both amino acid and nucleotide acid levels compared with the PPlcb of other vertebrates and invertebrates, and its Kozak motif contained in the 5＇UTR around ATG start codon is GXXAXXGXXATGG, which is different from mammalian in two positions A6 and G3, indicating the possibility of different initiation of translation in turbot, and also the 3＇UTR of SmPPlcb is highly diverse in the sequence similarity and length compared with other animals, especially zebraf＇lsh. The cloning and sequencing of SmPPlcb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.
文摘Glyceraldehyde-3-phosphate dehydrogenase （GAPDH）, initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. However, emerging evidence indicates that GAPDH is implicated in diverse functions independent of its role in energy metabolism; the expression status of GAPDH is also deregulated in various cancer cells. One of the most common effects of GAPDH is its inconsistent role in the determination of cancer cell fate. Furthermore, studies have described GAPDH as a regulator of cell death; other studies have suggested that GAPDH participates in tumor progression and serves as a new therapeutic target. However, related regulatory mechanisms of its numerous cellular functions and deregulated expression levels remain unclear. GAPDH is tightly regulated at transcriptional and pnsttranscriptional levels, which are involved in the regulation of diverse GAPDH functions. Several cancer-related factors, such as insulin, hypoxia inducible factor-1 （HIF-1）, p53, nitric oxide （NO）, and acetylated histone, not only modulate GAPDH gene expression but also affect protein functions via common pathways. Moreover, posttranslational modifications （PTMs） occurring in GAPDH in cancer cells result in new activities unrelated to the original glycnlytic function of GAPDH. In this review, recent findings related to GAPDH transcriptional regulation and PTMs are summarized. Mechanisms and pathways involved in GAPDH regulation and its different roles in cancer cells are also described.
基金Project supported by the National Natural Science Foundation of China (No. 39970146) the Interna- tional Rice Research Institute (IRRI) under project of Reversing Trends of Declining Productivity (RTDP).
文摘The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.
