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2. Cytology of Cutleria and Aglaozonia. A Preliminary Paper
- Author
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Yamanouchi, Shigéo
- Published
- 1909
3. Note on Dr. Jan Hirschler's Paper on Spindle Bridges, and the De Novo Origin of Moth Spermatocyte Golgi Bodies
- Author
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Gatenby, J. Brontë
- Published
- 1931
- Full Text
- View/download PDF
4. National Academy of Sciences Abstracts of Papers Presented at the Annual Meeting, Washington, D.C., 23-25 April 1962
- Published
- 1962
5. The Cell Structure of the Cyanophyceae.--Preliminary Paper
- Author
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Wager, Harold
- Published
- 1903
6. A Paper On The Origin Of Tumours
- Author
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Lockhart-Mummery, J. P.
- Published
- 1932
7. Abstract Of A Paper On The Molecular Theory Of Organisation (Concluded)
- Author
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Bennett, John Hughes
- Published
- 1861
8. Primary sequence of U-1 nuclear ribonucleic acid of Novikoff hepatoma ascites cells.
- Author
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Reddy R, Ro-Choi TS, Henning D, and Busch H
- Subjects
- Animals, Base Sequence, Carcinoma, Hepatocellular pathology, Cellulose, Centrifugation, Density Gradient, Chromatography, DEAE-Cellulose, Chromatography, Ion Exchange, Chromatography, Paper, Electrophoresis, Electrophoresis, Paper, Electrophoresis, Polyacrylamide Gel, Liver Neoplasms, Neoplasms, Experimental analysis, Neoplasms, Experimental pathology, Oligonucleotides analysis, Pancreas enzymology, Phosphorus Radioisotopes, Rats, Ribonucleases, Ribonucleotides analysis, Carcinoma, Hepatocellular analysis, Cell Nucleus analysis, RNA, Neoplasm analysis, RNA, Neoplasm isolation & purification
- Published
- 1974
9. Nuclear deoxyribonucleic acid polymerase. Purification and properties of the homogeneous enzyme from human KB cells.
- Author
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Wang TS, Sedwick WD, and Korn D
- Subjects
- Base Sequence, Carcinoma enzymology, Cell Line, Chromatography, Thin Layer, DNA Nucleotidyltransferases metabolism, Diphosphates, Electrophoresis, Paper, Electrophoresis, Polyacrylamide Gel, Escherichia coli enzymology, Exonucleases metabolism, Humans, Isoelectric Focusing, Kinetics, Magnesium pharmacology, Manganese pharmacology, Molecular Weight, Mouth Neoplasms enzymology, Phosphorus Radioisotopes, Templates, Genetic, Tritium, Cell Nucleus enzymology, DNA Nucleotidyltransferases isolation & purification
- Published
- 1974
10. Repair of O6-ethylguanine DNA lesions in isolated cell nuclei. Presence of the activity in the chromatin proteins.
- Author
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Renard A and Verly WG
- Subjects
- Animals, Chemical Phenomena, Chemistry, Chromatography, Paper, Diethylnitrosamine pharmacology, Ethylnitrosourea pharmacology, Guanine metabolism, Liver metabolism, Male, Rats, Rats, Inbred Strains, Cell Nucleus metabolism, Chromatin metabolism, DNA Repair drug effects, Guanine analogs & derivatives
- Abstract
Cell nuclei prepared from rat liver were alkylated in vitro with ethylnitrosourea; the nuclear DNA was found to lose O6-ethylguanine and 7-ethylguanine during a subsequent incubation at 37 degrees C. The rate of O6-ethylguanine loss is comparable to that observed in vivo, indicating that no cytoplasmic component is needed for the repair; no free O6-ethylguanine was found in the incubation medium of the ethylated nuclei. The rate of 7-ethylguanine loss is higher than the spontaneous depurination in vitro and an amount of free 7-ethylguanine equivalent to that lost by the nuclear DNA was found in the incubation medium; these results suggest that this DNA lesion is excised by a DNA glycosylase. The proteins of the chromatin prepared from the isolated nuclei induced the disappearance of O6-ethylguanine from an added ethylated DNA. No free O6-ethylguanine was released indicating that the repair is not catalyzed by a DNA glycosylase; no oligonucleotides enriched in O6-ethylguanine were released either, indicating that the disappearance of O6-ethylguanine from DNA is not the result of the cooperative action of a specific endonuclease and an exonuclease. Activities capable of removing O6-ethylguanine from DNA were found in other cell compartments; most of it, however, is in the nucleus where the main location is chromatin. A pretreatment of the rats with daily low doses of diethylnitrosamine during 3 or 4 weeks increased 2-3-times the repair activity of the chromatin proteins.
- Published
- 1983
- Full Text
- View/download PDF
11. Limited binding capacity sites for L-triiodothyronine in rat liver nuclei. Nuclear-cytoplasmic interrelation, binding constants, and cross-reactivity with L-thyroxine.
- Author
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Oppenheimer JH, Schwartz HL, Koerner D, and Surks MI
- Subjects
- Animals, Cell Fractionation, Chromatography, Paper, Cytoplasm metabolism, DNA metabolism, Iodine Radioisotopes, Liver metabolism, Mathematics, Models, Biological, Protein Binding, Radioimmunoassay, Rats, Thyroxine metabolism, Time Factors, Triiodothyronine blood, Binding Sites, Cell Nucleus metabolism, Liver cytology, Triiodothyronine metabolism
- Abstract
Further studies have been performed to define the kinetic characteristics of nuclear triiodothyronine (T(3)) binding sites in rat liver (J. Clin. Endocrinol. Metab. 1972. 35: 330). Sequential determination of labeled T(3) associated with nuclei and cytoplasm over a 4-h period allowed analysis of the relationship of T(3) in nuclear and cytoplasmic compartments. A rapid interchange of hormone between nuclei and cytoplasm was demonstrated, and in vitro incubation experiments with nuclei yielded no evidence favoring metabolic transformation of T(3) by the nuclei. In vivo displacement experiments were performed by subcellular fractionation of liver (1/2) h after injection of [(125)I]T(3) with increasing quantities of unlabeled T(3). The nuclear binding capacity for T(3) could be defined (0.52 ng/mg DNA). Analysis of these experiments also allowed an estimation of the association constant of nuclear sites for T(3) (4.7 x 10(11)M(-1)). The affinity of these sites for T(3) was estimated to be 20-40 fold greater than for thyroxine (T(4)). Chromatographic analysis of the nuclear radioactivity after injection of labeled T(4) indicated that the binding of T(4) by the nucleus could not be attributed to in vivo conversion of T(4) to T(3) but reflected intrinsic cross-reactivity of the two iodothyronines at the nuclear binding sites.
- Published
- 1974
- Full Text
- View/download PDF
12. Distribution of repetitious sequences in chick nuclear DNA.
- Author
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Tapiero H, Monier MN, Shaool D, and Harel J
- Subjects
- Animals, Base Sequence, Binding Sites, Centrifugation, Density Gradient, Chickens, Chromatography, Ion Exchange, Deoxyribonucleotides analysis, Edetic Acid, Electrophoresis, Paper, Evaluation Studies as Topic, Fibroblasts analysis, Fibroblasts cytology, Hydrogen-Ion Concentration, Hydroxyapatites, Kinetics, Methods, Nucleic Acid Conformation, Nucleic Acid Denaturation, Nucleic Acid Renaturation, Phosphorus Radioisotopes, Sodium Dodecyl Sulfate, Temperature, Cell Nucleus analysis, DNA analysis
- Abstract
By an improved method of hydroxylapatite chromatography, the reassociated sequences of chick nuclear DNA were isolated, and their base composition analysed. By increasing the amount of reassociation, the G + C content of the renatured sequences decreased progressively to reach a mean value corresponding to that of the total DNA. In order to study the distribution of the families, or group of families having different amount of reassociation, DNA was fractionated by CsC1 density gradient centrifugation. Fractions having different G + C content were obtained, and their reassociation rates analysed. At high C(o)t value of renaturation (C(o)t=50) the amount of reassociated sequences included in the high or in the low buoyant density DNA fractions was approximately the same, but their G + C content was as expected different. At lower C(o)t values of renaturation (between C(o)t of 0.2 and the C(o)t of 10), the results indicated an heterogeneity of the repeated sequences in the A + T rich DNA fractions, as compared to the G + C rich ones.
- Published
- 1974
- Full Text
- View/download PDF
13. Nuclear poly (ADPR) and mono (ADPR) residues in tissues with different growth rates.
- Author
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Adamietz P, Bredehorst R, Oldekop M, and Hilz H
- Subjects
- Adenosine Diphosphate, Aging, Alkaline Phosphatase, Animals, Animals, Newborn, Carcinoma, Ehrlich Tumor metabolism, Carcinoma, Ehrlich Tumor pathology, Cell Division, Chromatography, DEAE-Cellulose, Chromatography, Paper, Hydroxylamines, Liver cytology, Liver growth & development, Liver metabolism, Male, Mice, Mice, Inbred BALB C, NAD metabolism, Nucleoside Diphosphate Sugars analysis, Phosphoric Diester Hydrolases, Rats, Ribose, Snakes, Time Factors, Tritium, Venoms, Cell Nucleus metabolism, Nucleoside Diphosphate Sugars metabolism, Polynucleotides biosynthesis
- Published
- 1974
- Full Text
- View/download PDF
14. In vitro binding of L-triiodothyronine to receptors in rat liver nuclei. Kinectics of binding, extraction properties, and lack of requirement for cytosol proteins.
- Author
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Surks MI, Koerner DH, and Oppenheimer JH
- Subjects
- Animals, Binding Sites, Cattle, Cell Nucleus ultrastructure, Chromatography, Gel, Chromatography, Paper, In Vitro Techniques, Iodine Radioisotopes, Kinetics, Male, Potassium Chloride, Protein Binding, Rats, Sodium Chloride, Solubility, Time Factors, Cell Nucleus metabolism, Cytosol metabolism, Liver ultrastructure, Proteins metabolism, Receptors, Cell Surface, Triiodothyronine metabolism
- Abstract
Isolated hepatic nuclei from euthyroid rats were incubated with tracer (125I)L-triiodothyronine (T3) and increasing doses of nonradioactive T3 for 30 min at 37degrees C. The T3 bound specifically to nuclear sites increased with increasing T3 doses to a plateau, which represented the nuclear binding capacity, M. Addition of 1 mM KCN, NaF, dinitrophenol, oriodoacetate did not affect nuclear binding, indicating that active metabolism was not required. Kinetic studies showed that the nuclear sites were equilibrated with T3 within 30 min of incubation (one-half maximal binding at 3 min) and that the rate of release of T3 in vitro (0.058 min-1) was the same for endogenous T3 or for T3 bound to nuclei in vitro. Nuclear T3 resisted extraction with 0.14 M NaC1 buffered at pH 7.5, but both endogenous hormone and T3 bound in vitro were readily extracted by 0.4 M KC1 at pH 8.0. The elution profiles of endogenous and in vitro-bound T3 from Sephadex G-100 columns showed a common protein peak with a molecular weight of 60-65,000, assuming a globular protein. Scatchard analysis of in vitro displacement studies showed a single class of binding sites. Mean M equals 0.23 times 10-9 M or 0.85 ng T3 for nuclei isolated from 1 g of liver. Mean M closely corresponded to that anticipated from reported in vivo studies. The apparent association constant Ka for the nuclear sites, 5.55 times 108 M-1, was lower than in studies in vivo, probably attributable to the different ionic milieu of nuclei in the incubation buffer and in the intact cell. Thus, the identity of the nuclear T3 binding sites studied in vitro to those reported for endogenous hormone is demonstrated by similar binding capacities, release rates, analogue binding affinities (previously reported), and localization to chromatin nonhistone proteins of comparable molecular weight. The role of cytosol protein in nuclear binding was assessed by comparing binding parameters for extensively washed nuclei and nuclei incubated either with contaminating or added cytosol. No difference in Ka or M was found. Moreover, it was unlikely that specific cytosol proteins were already present in nuclei and functioned during incubation as a shuttle for T3, since Ka and M for nuclei obtained from athyreotic rats were similar to Ka and M for nuclei from euthyroid animals. Thus, an initial interaction between T3 and specific cytosol proteins does not appear to be a prerequisite for translocation of T3 to nuclear sites.
- Published
- 1975
- Full Text
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15. Maturation pathway for Novikoff ascites hepatoma 5.8 S ribosomal ribonucleic acid. Evidence for its presence in 32 S nuclear ribonucleic acid.
- Author
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Nazar RN, Owens TW, Sitz TO, and Busch H
- Subjects
- Alkaline Phosphatase, Animals, Base Sequence, Carcinoma, Hepatocellular metabolism, Chromatography, Ion Exchange, Chromatography, Paper, Liver Neoplasms, Neoplasms, Experimental analysis, Neoplasms, Experimental metabolism, Oligonucleotides analysis, Pancreas enzymology, Phosphoric Diester Hydrolases, Rats, Ribonucleases, Ribonucleotides analysis, Spleen enzymology, Carcinoma, Hepatocellular analysis, Cell Nucleus analysis, RNA, Neoplasm biosynthesis
- Abstract
Evidence that 32 S nRNA contains 5.8 S rRNA was provided by studies on specific oligonucleotide sequences of these RNA species. Purified 32P-labeled 5.8 and 28 S rRNA and 32 S RNA were digested with T-1 ribonuclease, and the products were fractionated according to chain length by chromatography on DEAE-Sephadex A-25 at neutral pH. The oligonucleotides in Peak 8 were treated with alkaline phosphatase and the products were separated by two-dimensional electrophoresis on cellulose acetate at pH 3.5 and DEAE-paper in 7% formic acid. Seven unique oligonucleotide markers for 5.8 S rRNA including the methylated octanucleotide A-A-U-U-Gm-G-A-Gp were present in 32 S RNA but were not found in 28 S rRNA, indicating that 5.8 S rRNA is directly derived from the 32 S nucleolar precursor. These studies confirm a maturation pathway for rRNA species in which 32 S nucleolar RNA is a precursor of 5.8 S rRNA as well as 28 S rRNA.
- Published
- 1975
16. How a phase image of a cell with nucleus refractive index smaller than that of the cytoplasm should look like?: A Comment on two papers by Steelman et al. and Schürmann et al. Read the Responses to this Comment: e201800091 and e201800095
- Author
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Maxim A, Yurkin
- Subjects
Cell Nucleus ,Cytoplasm ,Refractometry ,Article - Abstract
Recently, Maxim A. Yurkin commented on our paper “Is the nuclear refractive index lower than cytoplasm? Validation of phase measurements and implications for light scattering technologies” as well as on a complementary study “Cell nuclei have lower refractive index and mass density than cytoplasm” from Schürmann et al. In his comment, Yurkin concluded that quantitative phase images of cells with nuclei that are less optically dense than the cytoplasm must exhibit a characteristic concavity, the absence of which is evidence against our conclusion of a less-dense nucleus. In this response, we suggest that Yurkin’s conclusion is reached through an oversimplification of the spatial refractive index distribution within cells, which does not account for high index inclusions such as the nucleolus. We further cite recent studies in 3-dimensional refractive index imaging, in which the preponderance of studies supports our conclusion. Finally, we comment on the current state of knowledge regarding subcellular refractive index distributions in living cells.
- Published
- 2018
17. Incorporation of 14-C-choline into phospholipids of rat liver microsome subfractions: evidence against formation of endoplasmic reticulum from the nuclear membrane.
- Author
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Hallinan T, Duffy T, Waddington S, and Munro HN
- Subjects
- Animals, Chromatography, Paper, Chromatography, Thin Layer, In Vitro Techniques, Liver cytology, Phosphatidylcholines biosynthesis, Rats, Sphingomyelins biosynthesis, Cell Nucleus metabolism, Choline metabolism, Endoplasmic Reticulum, Liver metabolism, Microsomes metabolism, Phospholipids biosynthesis
- Published
- 1966
- Full Text
- View/download PDF
18. Progesterone "receptors" in the cytoplasm and nucleus of chick oviduct target tissue.
- Author
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O'Malley BW, Sherman MR, and Toft DO
- Subjects
- Aldosterone metabolism, Animals, Centrifugation, Density Gradient, Chickens, Chromatography, Gel, Chromatography, Paper, Estrone metabolism, Female, Hydrocortisone metabolism, Ketones metabolism, Macromolecular Substances metabolism, Pregnanes metabolism, Protein Binding, Receptors, Drug, Sucrose, Tritium, Binding Sites, Cell Nucleus metabolism, Cytoplasm metabolism, Oviducts metabolism, Progesterone metabolism
- Abstract
This report demonstrates that the chick oviduct, a specific target organ for progesterone, contains both cytoplasmic and nuclear macromolecules which bind progestins. These binding molecules can be clearly distinguished from transcortin by centrifugation through sucrose gradients of low ionic strength and by agarose gel filtration. The cytoplasmic progesterone-binding molecules also bind 5-alpha-pregnane-3,20-dione, but have significantly lower affinity for cortisol, estrone, or aldosterone. They are absent from blood and nontarget organs such as lung and spleen. The tissue-specific binding components appear to be heat-labile proteins with an average dissociation constant for progesterone of about 8 x 10(-10) M at 2 degrees C. These results are consistent with the identification of the progesterone-binding molecules as the functional hormone receptors. In further support of this concept is the finding that treatment of the chicks with estrogen coordinately induces a 20-fold increase in the number of progesterone-binding molecules and enhances the capacity of progesterone to induce avidin synthesis.A progesterone-"receptor" complex can be detected in both the cytoplasm and nuclei of oviduct tissue after an injection of [(3)H]progesterone to estrogen-treated chicks. By contrast, incubation of oviduct tissue with [(3)H]progesterone in vitro at 2 degrees C for 5 min leads to labeling of the cytoplasmic "receptor" only. Transfer of the "receptor"-steroid complex into the nucleus then appears to occur upon subsequent incubation in vitro at 37 degrees C. This observation suggests that the transfer of bound progesterone across the nuclear membrane may be an energy-requiring enzymatic process.
- Published
- 1970
- Full Text
- View/download PDF
19. The terminal nucleotidyltransferases of calf thymus nuclei.
- Author
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Gottesman ME and Canellakis ES
- Subjects
- Adenosine Triphosphate metabolism, Animals, Cattle, Chromatography, Paper, DNA biosynthesis, Diphosphates metabolism, Edetic Acid pharmacology, Guanine Nucleotides metabolism, In Vitro Techniques, Thymus Gland cytology, Cell Nucleus enzymology, Nucleotidyltransferases metabolism, Thymus Gland enzymology
- Published
- 1966
20. Cooperation of mitochondrial and nuclear genes specifying the mitochondrial genetic apparatus in Neurospora crassa.
- Author
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Barath Z and Küntzel H
- Subjects
- Cell Nucleus enzymology, Chloramphenicol pharmacology, Chromatography, Gel, Electrophoresis, Paper, Enzyme Induction drug effects, Ethidium pharmacology, Formates, Methionine, Mitochondria enzymology, Neurospora crassa metabolism, Peptide Chain Elongation, Translational drug effects, RNA biosynthesis, RNA, Transfer, Ribosomes metabolism, Tetrahydrofolates, Transferases metabolism, Cell Nucleus metabolism, Genes, Regulator, Genetic Code, Mitochondria metabolism, Neurospora metabolism
- Abstract
Enzymes involved in the expression of the mitochondrial genome in Neurospora crassa are induced by chloramphenicol and ethidium bromide, which block transcription and translation of mitochondrial DNA. It is concluded that most, if not all, proteins of the mitochondrial genetic apparatus are coded by nuclear genes, synthesized on cytoplasmic ribosomes, and controlled by a repressor-like mitochondrial gene product. A model explaining the coordination of nuclear and mitochondrial division cycles by repressor control is discussed.
- Published
- 1972
- Full Text
- View/download PDF
21. Nuclear cytidine 5'-monophosphosialic acid synthetase.
- Author
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Kean EL
- Subjects
- Animals, Brain enzymology, Chromatography, Paper, Cytoplasm enzymology, Cytosine Nucleotides, DNA analysis, Electrophoresis, Hydrogen-Ion Concentration, Hypertonic Solutions, Kidney enzymology, Kinetics, Liver cytology, Magnesium pharmacology, Metals pharmacology, Neuraminic Acids pharmacology, Nucleotides pharmacology, RNA analysis, Rats, Retina cytology, Spleen enzymology, Stimulation, Chemical, Swine, Cell Nucleus enzymology, Ligases metabolism, Liver enzymology, Retina enzymology
- Published
- 1970
22. 2'-O-methylation of adenosine, guanosine, uridine, and cytidine in RNA of isolated rat liver nuclei.
- Author
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al-Arif A and Sporn MB
- Subjects
- Adenine Nucleotides metabolism, Alkaline Phosphatase, Animals, Cell Nucleus drug effects, Chromatography, DEAE-Cellulose, Chromatography, Paper, Cytosine Nucleotides metabolism, Guanine Nucleotides metabolism, Hydrolysis, Kinetics, Liver cytology, Methyl Ethers biosynthesis, Phosphoric Diester Hydrolases, Plants, Polynucleotides pharmacology, RNA, Ribosomal pharmacology, RNA, Transfer pharmacology, Rats, S-Adenosylmethionine metabolism, Tritium, Uracil Nucleotides metabolism, Cell Nucleus metabolism, Liver metabolism, Methylation, RNA metabolism
- Abstract
Nuclei isolated from rat liver, when incubated with methyl-labeled S-adenosylmethionine, incorporated label into 2'-O-methyladenosine, 2'-O-methylguanosine, 2'-O-methyluridine, and 2'-O-methylcytidine of endogenous nuclear RNA. Addition of ribosomal RNA from wheat germ to the reaction markedly stimulated 2'-O-methylation of total RNA. The relative incorporation of label into the four different 2'-O-methyl ribonucleosides was greatly changed by the addition of wheat germ RNA. There was much more 2'-O-methylation of the purine ribonucleosides, relative to the pyrimidine ribonucleosides, in the reaction stimulated by wheat germ RNA.
- Published
- 1972
- Full Text
- View/download PDF
23. Comparison of physicochemical properties of mitochondrial and nuclear deoxyribonucleic acid from rat liver cells.
- Author
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Kazakova TB and Markosian KA
- Subjects
- Adenine analysis, Animals, Chromatography, Paper, Cytosine analysis, Guanine analysis, In Vitro Techniques, Rats, Thymine analysis, Ultracentrifugation, Cell Nucleus, DNA analysis, Liver cytology, Mitochondria
- Published
- 1966
- Full Text
- View/download PDF
24. Studies of phosphorus metabolism by isolated nuclei. VII. Identification of polyphosphate as a product.
- Author
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Griffin JB, Davidian NM, and Penniall R
- Subjects
- Animals, Chemistry Techniques, Analytical, Chromatography, Paper, In Vitro Techniques, Liver cytology, Phosphorus Isotopes metabolism, Rats, Cell Nucleus metabolism, Phosphates metabolism
- Published
- 1965
25. The permeability of the amphibian oocyte nucleus, in situ.
- Author
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Horowitz SB
- Subjects
- Animals, Autoradiography, Biological Transport, Chromatography, Paper, Diffusion, Female, Micromanipulation, Rana pipiens, Sucrose metabolism, Tritium, Cell Nucleus metabolism, Ovum cytology, Permeability
- Abstract
Ultralow temperature radioautography, suitable for the quantitative localization of diffusible solutes, was used to study the permeability of the nuclear envelope in the intact amphibian oocyte Sucrose-(3)H solutions were injected into mature oocytes, in volumes of 0 016-0 14% of that of the cell, and the subsequent movement of the solute was recorded. The resultant radioautographs show diffusion gradients in the cytoplasm and nucleus, and concentration gradients across the nuclear envelope Analysis of these gradients discloses that the nuclear envelope is as permeable as a comparable structure composed of cytoplasm, and is about 10(8) times more permeable than the oocyte plasma membrane The diffusion coefficient of sucrose in cytoplasm is 2 x 10(-6) cm(2)/sec, or about one-third its diffusivity in pure water. This reduction can probably be accounted for by an effective lengthening of the diffusional path because of obstruction by cytoplasmic inclusions. The nuclear: cytoplasmic sucrose concentration ratio at diffusional equilibrium is about 3 05, or 1.6 times as great as expected from the water content of the two compartments This asymmetry is attributed to an unavailability of 36% of the cytoplasmic water as solvent Finally, sucrose entry into oocytes from a bathing solution was monitored by whole cell analysis and radioautography. These and the microinjection results are consistent with a model in which sucrose entry into the cell is entirely limited by the permeability of the plasma membrane. The results are inconsistent with cell models that hypothesize a short-circuit transport route from the extracellular compartment to the nucleus, and with models in which cytoplasmic diffusion is viewed as limiting the rate of solute permeation.
- Published
- 1972
- Full Text
- View/download PDF
26. Purification and partial characterisation of rat-liver nuclear DNA polymerase.
- Author
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Haines ME, Wickremasinghe RG, and Johnston IR
- Subjects
- Animals, Chromatography, Gel, Chromatography, Ion Exchange, Chromatography, Paper, DNA, Deoxyribonucleases, Electrophoresis, Polyacrylamide Gel, Endonucleases, Liver cytology, Macromolecular Substances, Molecular Weight, Nucleotides, Osmolar Concentration, Phosphotransferases, Rats, Sodium Dodecyl Sulfate, Templates, Genetic, Thymine Nucleotides, Tritium, Cell Nucleus enzymology, DNA Nucleotidyltransferases isolation & purification, Liver enzymology
- Published
- 1972
- Full Text
- View/download PDF
27. Circulating hemocytes from larvae of the paper wasp Polistes dominulus (Hymenoptera, Vespidae)
- Author
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Fabio Manfredini, Enzo Ottaviani, and Romano Dallai
- Subjects
Cytoplasm ,Hemocytes ,Cytoplasmic inclusion ,Wasps ,Hymenoptera ,Cytoplasmic Granules ,Phagocytosis ,Phagosomes ,medicine ,Cell Adhesion ,Animals ,Paper wasp ,Cell Nucleus ,Organelles ,Behavior ,Vespidae ,biology ,Ultrastructure ,Cell Biology ,General Medicine ,Anatomy ,biology.organism_classification ,Cell biology ,medicine.anatomical_structure ,Cell culture ,Larva ,Nucleus ,Developmental Biology - Abstract
Circulating hemocytes from larval stages of the paper wasp Polistes dominulus were characterized by light and transmission electron microscopy. Three types were identified: prohemocytes, plasmatocytes and granulocytes. The first two are agranular cells while the latter present typical cytoplasmic inclusions called granules. Plasmatocytes differ from prohemocytes being larger, showing lower nucleus/cytoplasm ratio and they possess many phagolysosomes. The substantial uniformity of most subcellular features and the presence of "intermediate forms" support the "single-cell theory" i.e., there is only one cell line that originates from the prohemocyte and leads to the granular cell passing through the plasmatocyte. This hypothesis seems to be confirmed by functional tests. Indeed, most part of cells adheres to the glass and is able to phagocytize fluorescent microspheres.
- Published
- 2008
28. Colloquium paper: bioenergetics, the origins of complexity, and the ascent of man
- Author
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Douglas C, Wallace
- Subjects
Cell Nucleus ,Colloquium Papers ,Mutation ,Electrochemistry ,Animals ,Humans ,DNA ,Selection, Genetic ,Energy Metabolism ,Biological Evolution ,Membrane Potentials ,Mitochondria - Abstract
Complex structures are generated and maintained through energy flux. Structures embody information, and biological information is stored in nucleic acids. The progressive increase in biological complexity over geologic time is thus the consequence of the information-generating power of energy flow plus the information-accumulating capacity of DNA, winnowed by natural selection. Consequently, the most important component of the biological environment is energy flow: the availability of calories and their use for growth, survival, and reproduction. Animals can exploit and adapt to available energy resources at three levels. They can evolve different anatomical forms through nuclear DNA (nDNA) mutations permitting exploitation of alternative energy reservoirs, resulting in new species. They can evolve modified bioenergetic physiologies within a species, primarily through the high mutation rate of mitochondrial DNA (mtDNA)–encoded bioenergetic genes, permitting adjustment to regional energetic environments. They can alter the epigenomic regulation of the thousands of dispersed bioenergetic genes via mitochondrially generated high-energy intermediates permitting individual accommodation to short-term environmental energetic fluctuations. Because medicine pertains to a single species, Homo sapiens, functional human variation often involves sequence changes in bioenergetic genes, most commonly mtDNA mutations, plus changes in the expression of bioenergetic genes mediated by the epigenome. Consequently, common nDNA polymorphisms in anatomical genes may represent only a fraction of the genetic variation associated with the common “complex” diseases, and the ascent of man has been the product of 3.5 billion years of information generation by energy flow, accumulated and preserved in DNA and edited by natural selection.
- Published
- 2010
29. Comparative proteomic analysis of nuclear and cytoplasmic compartments in human cardiac progenitor cells.
- Author
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Albericio G, Aguilar S, Torán JL, Yañez R, López JA, Vázquez J, Mora C, and Bernad A
- Subjects
- Cell Movement, Cell Proliferation, Cells, Cultured, Gene Expression Regulation, HMGA2 Protein genetics, HMGA2 Protein metabolism, Humans, Interleukin-1alpha genetics, Interleukin-1alpha metabolism, Oxidative Stress, RNA-Binding Proteins genetics, RNA-Binding Proteins metabolism, Receptor-Like Protein Tyrosine Phosphatases, Class 2 genetics, Receptor-Like Protein Tyrosine Phosphatases, Class 2 metabolism, Signal Transduction, Cell Nucleus metabolism, Cytoplasm metabolism, Fibroblasts metabolism, Mesenchymal Stem Cells metabolism, Myocytes, Cardiac metabolism, Proteome, Proteomics
- Abstract
Clinical trials evaluating cardiac progenitor cells (CPC) demonstrated feasibility and safety, but no clear functional benefits. Therefore a deeper understanding of CPC biology is warranted to inform strategies capable to enhance their therapeutic potential. Here we have defined, using a label-free proteomic approach, the differential cytoplasmic and nuclear compartments of human CPC (hCPC). Global analysis of cytoplasmic repertoire in hCPC suggested an important hypoxia response capacity and active collagen metabolism. In addition, comparative analysis of the nuclear protein compartment identified a significant regulation of a small number of proteins in hCPC versus human mesenchymal stem cells (hMSC). Two proteins significantly upregulated in the hCPC nuclear compartment, IL1A and IMP3, showed also a parallel increase in mRNA expression in hCPC versus hMSC, and were studied further. IL1A, subjected to an important post-transcriptional regulation, was demonstrated to act as a dual-function cytokine with a plausible role in apoptosis regulation. The knockdown of the mRNA binding protein (IMP3) did not negatively impact hCPC viability, but reduced their proliferation and migration capacity. Analysis of a panel of putative candidate genes identified HMGA2 and PTPRF as IMP3 targets in hCPC. Therefore, they are potentially involved in hCPC proliferation/migration regulation., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
30. New insights into the biogenesis of nuclear RNA polymerases?This paper is one of a selection of papers published in this special issue entitled 'Canadian Society of Biochemistry, Molecular & Cellular Biology 52nd Annual Meeting — Protein Folding: Principles and Diseases' and has undergone the Journal's usual peer review process
- Author
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Philippe Cloutier and Benoit Coulombe
- Subjects
biology ,RNA ,RNA polymerase II ,Cell Biology ,Biochemistry ,enzymes and coenzymes (carbohydrates) ,Cell nucleus ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Transcription (biology) ,RNA polymerase ,biology.protein ,medicine ,bacteria ,Transcription factor II D ,Molecular Biology ,Polymerase ,Biogenesis - Abstract
More than 30 years of research on nuclear RNA polymerases (RNAP I, II, and III) has uncovered numerous factors that regulate the activity of these enzymes during the transcription reaction. However, very little is known about the machinery that regulates the fate of RNAPs before or after transcription. In particular, the mechanisms of biogenesis of the 3 nuclear RNAPs, which comprise both common and specific subunits, remains mostly uncharacterized and the proteins involved are yet to be discovered. Using protein affinity purification coupled to mass spectrometry (AP–MS), we recently unraveled a high-density interaction network formed by nuclear RNAP subunits from the soluble fraction of human cell extracts. Validation of the dataset using a machine learning approach trained to minimize the rate of false positives and false negatives yielded a high-confidence dataset and uncovered novel interactors that regulate the RNAP II transcription machinery, including a set of proteins we named the RNAP II-associated proteins (RPAPs). One of the RPAPs, RPAP3, is part of an 11-subunit complex we termed the RPAP3/R2TP/prefoldin-like complex. Here, we review the literature on the subunits of this complex, which points to a role in nuclear RNAP biogenesis.
- Published
- 2010
31. The photoreactivation of 6 - 4 photoproducts in chloroplast and nuclear DNA depends on the amount of the Arabidopsis UV repair defective 3 protein.
- Author
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Zgłobicki P, Hermanowicz P, Kłodawska K, Bażant A, Łabuz J, Grzyb J, Dutka M, Kowalska E, Jawor J, Leja K, and Banaś AK
- Subjects
- Ultraviolet Rays, DNA, Plant metabolism, DNA, Plant genetics, Pyrimidine Dimers metabolism, Pyrimidine Dimers genetics, DNA, Chloroplast genetics, DNA, Chloroplast metabolism, Chloroplasts metabolism, DNA Damage, Arabidopsis genetics, Arabidopsis radiation effects, Arabidopsis metabolism, Arabidopsis Proteins metabolism, Arabidopsis Proteins genetics, Cell Nucleus metabolism, Cell Nucleus radiation effects, Deoxyribodipyrimidine Photo-Lyase metabolism, Deoxyribodipyrimidine Photo-Lyase genetics, Plants, Genetically Modified, DNA Repair
- Abstract
Background: 6 - 4 photoproducts are the second most common UV-induced DNA lesions after cyclobutane pyrimidine dimers. In plants, they are mainly repaired by photolyases in a process called photoreactivation. While pyrimidine dimers can be deleterious, leading to mutagenesis or even cell death, 6 - 4 photoproducts can activate specific signaling pathways. Therefore, their removal is particularly important, especially for plants exposed to high UV intensities due to their sessile nature. Although photoreactivation in nuclear DNA is well-known, its role in plant organelles remains unclear. In this paper we analyzed the activity and localization of GFP-tagged AtUVR3, the 6 - 4 photoproduct specific photolyase., Results: Using transgenic Arabidopsis with different expression levels of AtUVR3, we confirmed a positive trend between these levels and the rate of 6 - 4 photoproduct removal under blue light. Measurements of 6 - 4 photoproduct levels in chloroplast and nuclear DNA of wild type, photolyase mutants, and transgenic plants overexpressing AtUVR3 showed that the photoreactivation is the main repair pathway responsible for the removal of these lesions in both organelles. The GFP-tagged AtUVR3 was predominantly located in nuclei with a small fraction present in chloroplasts and mitochondria of transgenic Arabidopsis thaliana and Nicotiana tabacum lines. In chloroplasts, this photolyase co-localized with the nucleoid marked by plastid envelope DNA binding protein., Conclusions: Photolyases are mainly localized in plant nuclei, with only a small fraction present in chloroplasts and mitochondria. Despite this unbalanced distribution, photoreactivation is the primary mechanism responsible for the removal of 6 - 4 photoproducts from nuclear and chloroplast DNA in adult leaves. The amount of the AtUVR3 photolyase is the limiting factor influencing the photoreactivation rate of 6 - 4 photoproducts. The efficient photoreactivation of 6 - 4 photoproducts in 35S: AtUVR3-GFP Arabidopsis and Nicotiana tabacum is a promising starting point to evaluate whether transgenic crops overproducing this photolyase are more tolerant to high UV irradiation and how they respond to other abiotic and biotic stresses under field conditions., (© 2024. The Author(s).)
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- 2024
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32. FAK, vinculin, and talin control mechanosensitive YAP nuclear localization.
- Author
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Holland EN, Fernández-Yagüe MA, Zhou DW, O'Neill EB, Woodfolk AU, Mora-Boza A, Fu J, Schlaepfer DD, and García AJ
- Subjects
- Humans, Adaptor Proteins, Signal Transducing metabolism, Transcription Factors metabolism, Mesenchymal Stem Cells metabolism, Mesenchymal Stem Cells cytology, Animals, Focal Adhesions metabolism, Mice, Fibroblasts metabolism, Focal Adhesion Kinase 1 metabolism, Focal Adhesion Protein-Tyrosine Kinases metabolism, Protein Binding, Talin metabolism, Vinculin metabolism, Cell Nucleus metabolism, YAP-Signaling Proteins metabolism, Mechanotransduction, Cellular
- Abstract
Focal adhesions (FAs) are nanoscale complexes containing clustered integrin receptors and intracellular structural and signaling proteins that function as principal sites of mechanotransduction in part via promoting the nuclear translocation and activation of the transcriptional coactivator yes-associated protein (YAP). Knockdown of FA proteins such as focal adhesion kinase (FAK), talin, and vinculin can prevent YAP nuclear localization. However, the mechanism(s) of action remain poorly understood. Herein, we investigated the role of different functional domains in vinculin, talin, and FAK in regulating YAP nuclear localization. Using genetic or pharmacological inhibition of fibroblasts and human mesenchymal stem cells (hMSCs) adhering to deformable substrates, we find that disruption of vinculin-talin binding versus talin-FAK binding reduces YAP nuclear localization and transcriptional activity via different mechanisms. Disruption of vinculin-talin binding or knockdown of talin-1 reduces nuclear size, traction forces, and YAP nuclear localization. In contrast, disruption of the talin binding site on FAK or elimination of FAK catalytic activity did not alter nuclear size yet still prevented YAP nuclear localization and activity. These data support both nuclear tension-dependent and independent models for matrix stiffness-regulated YAP nuclear localization. Our results highlight the importance of vinculin-talin-FAK interactions at FAs of adherent cells, controlling YAP nuclear localization and activity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
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- 2024
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33. Re-assessment of the subcellular localization of Bazooka/Par-3 in Drosophila: no evidence for localization to the nucleus and the neuromuscular junction.
- Author
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Kim S, Shahab J, Vogelsang E, and Wodarz A
- Subjects
- Animals, Protein Transport, Cell Nucleus metabolism, Drosophila Proteins metabolism, Drosophila Proteins genetics, Neuromuscular Junction metabolism, Drosophila melanogaster genetics, Drosophila melanogaster metabolism
- Abstract
Bazooka/Par-3 (Baz) is an evolutionarily conserved scaffold protein that functions as a master regulator for the establishment and maintenance of cell polarity in many different cell types. In the vast majority of published research papers Baz has been reported to localize at the cell cortex and at intercellular junctions. However, there have also been several reports showing localization and function of Baz at additional subcellular sites, in particular the nuclear envelope and the neuromuscular junction. In this study we have re-assessed the localization of Baz to these subcellular sites in a systematic manner. We used antibodies raised in different host animals against different epitopes of Baz for confocal imaging of Drosophila tissues. We tested the specificity of these antisera by mosaic analysis with null mutant baz alleles and tissue-specific RNAi against baz. In addition, we used a GFP-tagged gene trap line for Baz and a bacterial artificial chromosome (BAC) expressing GFP-tagged Baz under control of its endogenous promoter in a baz mutant background to compare the subcellular localization of the GFP-Baz fusion proteins to the staining with anti-Baz antisera. Together, these experiments did not provide evidence for specific localization of Baz to the nucleus or the neuromuscular junction., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)
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- 2024
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34. BoNuS: Boundary Mining for Nuclei Segmentation With Partial Point Labels.
- Author
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Lin Y, Wang Z, Zhang D, Cheng KT, and Chen H
- Subjects
- Humans, Image Processing, Computer-Assisted methods, Databases, Factual, Image Interpretation, Computer-Assisted methods, Cell Nucleus, Algorithms
- Abstract
Nuclei segmentation is a fundamental prerequisite in the digital pathology workflow. The development of automated methods for nuclei segmentation enables quantitative analysis of the wide existence and large variances in nuclei morphometry in histopathology images. However, manual annotation of tens of thousands of nuclei is tedious and time-consuming, which requires significant amount of human effort and domain-specific expertise. To alleviate this problem, in this paper, we propose a weakly-supervised nuclei segmentation method that only requires partial point labels of nuclei. Specifically, we propose a novel boundary mining framework for nuclei segmentation, named BoNuS, which simultaneously learns nuclei interior and boundary information from the point labels. To achieve this goal, we propose a novel boundary mining loss, which guides the model to learn the boundary information by exploring the pairwise pixel affinity in a multiple-instance learning manner. Then, we consider a more challenging problem, i.e., partial point label, where we propose a nuclei detection module with curriculum learning to detect the missing nuclei with prior morphological knowledge. The proposed method is validated on three public datasets, MoNuSeg, CPM, and CoNIC datasets. Experimental results demonstrate the superior performance of our method to the state-of-the-art weakly-supervised nuclei segmentation methods. Code: https://github.com/hust-linyi/bonus.
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- 2024
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35. Different rates of pollen and seed gene flow cause branch‐length and geographic cytonuclear discordance within Asian butternuts
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Bowen Zhang, Xin-Rui Lin, Lin-Lin Xu, Wei-Ning Bai, Rui-Min Yu, Kui Lin, Da-Yong Zhang, Nan Li, and CiiM, Zentrum für individualisierte Infektionsmedizin, Feodor-Lynen-Str.7, 30625 Hannover.
- Subjects
Gene Flow ,Nuclear gene ,Physiology ,Lineage (evolution) ,whole-genome resequencing ,introgression ,Introgression ,Plant Science ,whole‐genome resequencing ,Biology ,Genome ,Gene flow ,Coalescent theory ,Genome, Chloroplast ,Phylogeny ,Cell Nucleus ,Full Paper ,Research ,food and beverages ,Cline (biology) ,Full Papers ,branch-length discordance ,geographic discordance ,Evolutionary biology ,Seeds ,Pollen ,Biological dispersal ,branch‐length discordance ,gene flow - Abstract
Summary Topological cytonuclear discordance is commonly observed in plant phylogenetic and phylogeographic studies, yet few studies have attempted to detect two other forms of cytonuclear discordance (branch length and geographical) and to uncover the causes of the discordance.We used the whole nuclear and chloroplast genome data from 80 individual Asian butternuts to reveal the pattern and processes of cytonuclear discordance.Our findings indicate that the chloroplast genome had substantially deeper divergence (branch‐length discordance) and a steeper cline in the contact zone (geographic discordance) compared with the nuclear genome. After various hypothesis have been tested, the results suggest that incomplete lineage sorting, positive selection and cytonuclear incompatibility are probably insufficient to explain this pattern. However, isolation‐by‐distance analysis and gene flow estimation point to a much higher level of gene flow by pollen compared with by seeds, which may have slowed down lineage divergence and mediated wider contact for nuclear genome compared with the chloroplast genome.Altogether, this study highlights a critical role of sex‐biased dispersal in causing discordance between the nuclear and plastid genome of Asian butternuts. Given its ubiquity among plants, asymmetric gene flow should be given a high priority in future studies of cytonuclear discordance.
- Published
- 2021
36. The protective effects of Olmesartan against interleukin-29 (IL-29)-induced type 2 collagen degradation in human chondrocytes
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Yunlong Liu, Junyi Liu, Yan Ma, Yongyong Zhang, Qiong Chen, Xin Yang, and Yanchun Shang
- Subjects
Cell Survival ,extracellular matrix ,Anti-Inflammatory Agents ,Tetrazoles ,Bioengineering ,Applied Microbiology and Biotechnology ,Models, Biological ,Cell Line ,Chondrocytes ,Transforming Growth Factor beta ,Osteoarthritis ,Olmesartan ,Humans ,Collagen Type II ,IL-29 ,Cell Proliferation ,Cell Nucleus ,Interleukins ,Imidazoles ,General Medicine ,Gene Expression Regulation ,Proteolysis ,TP248.13-248.65 ,Biotechnology ,Research Article ,Research Paper - Abstract
Osteoarthritis (OA) is a cartilage degenerative disease commonly observed in the elderly population and is pathologically characterized by the degradation of the cartilage extracellular matrix (ECM). Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) are critical enzymes involved in the degradation of ECM. Olmesartan is an inhibitor of the angiotensin II receptor developed for the treatment of hypertension, and recent studies show that it exerts anti-inflammatory effects in arthritis. The present study aimed to investigate the mechanism of the protective effect of Olmesartan on cartilage ECM degradation. Interleukin-29 (IL-29) is a novel inflammatory mediator involved in the inflammation and degradation of cartilage in OA, and human T/C-28a2 cells treated with it were the inflammatory model in vitro. We found that the degradation of type 2 collagens and aggrecans was induced by IL-29, accompanied by the upregulation of MMPs and ADAMTSs, but the presence of Olmesartan significantly ameliorated these increases. In addition, Olmesartan abolished IL-29- induced oxidative stress and elevated the expression level of TNF receptor-associated factor 6 (TRAF-6). Mechanistically, we showed that Olmesartan suppressed IL-29- caused inhibitor kappa B α (IκBα) expression and nuclear translocation of nuclear factor kappa-B (NF-κB) p65, indicating it suppressed the activation of the NF-κB pathway. Collectively, our data reveal that Olmesartan exerted a protective function on IL-29- induced type 2 collagen degradation in human chondrocytes.
- Published
- 2022
37. Long non-coding RNA H19 aggravates keloid progression by upregulating SMAD family member 5 expression via miR-196b-5p
- Author
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Li, Zhichao, Gong, Cheng, and Wei, Huiming
- Subjects
Smad5 Protein ,Cytoplasm ,Cell Survival ,Primary Cell Culture ,Down-Regulation ,lncrna h19 ,Bioengineering ,Applied Microbiology and Biotechnology ,Cell Movement ,Humans ,smad5 ,skin and connective tissue diseases ,Cells, Cultured ,Cell Proliferation ,Cell Nucleus ,General Medicine ,Fibroblasts ,mir-196b-5p ,female genital diseases and pregnancy complications ,keloid ,MicroRNAs ,embryonic structures ,Disease Progression ,RNA, Long Noncoding ,TP248.13-248.65 ,Research Article ,Research Paper ,Biotechnology - Abstract
Accumulating evidence suggests that long non-coding RNAs (lncRNAs) participate in the formation and development of keloids, a benign tumor. In addition, lncRNA H19 has been shown to act on the biological processes of keloids. This study aimed to identify other important mechanisms of the effect of lncRNA H19 on keloid formation. The H19, miR-196b-5p, and SMAD family member 5 (SMAD5) expression levels were detected using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blotting. Subcellular localization of lncRNA H19 was detected using a nuclear–cytoplasmic separation assay. Cell viability and proliferation were measured using counting kit-8 and colony formation assays. Bax and Bcl-2 levels were examined using Western blot analysis. The interaction between H19 and miR-196b-5p or SMAD5 was verified using a dual-luciferase reporter assay. H19 and SMAD5 expression was upregulated in keloid tissue and fibroblasts, whereas miR-196b-5p expression was downregulated. Knockdown of H19, overexpression of miR-196b-5p, or knockdown of SMAD5 inhibited the viability and proliferation of keloid fibroblasts and promoted apoptosis. Overexpression of H19 or SMAD5 and knockdown of miR-196b-5p promoted viability and proliferation and inhibited apoptosis. miR-196b-5p was identified as a H19 sponge, and SMAD5 was identified as a miR-196b-5p target. The combination of lncRNA H19 and miR-196b-5p regulates SMAD5 expression and promotes keloid formation, thus providing a new direction for keloid treatment.
- Published
- 2022
38. Protective effect of dexmedetomidine in cecal ligation perforation-induced acute lung injury through HMGB1/RAGE pathway regulation and pyroptosis activation
- Author
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Huaqin Sun, Mingsun Fang, Hongyi Hu, Xiaoping Xu, Zhehao Liang, and Tao Tao
- Subjects
Male ,animal diseases ,Acute Lung Injury ,Receptor for Advanced Glycation End Products ,Perforation (oil well) ,Bioengineering ,Lung injury ,Pharmacology ,Protective Agents ,HMGB1 ,Applied Microbiology and Biotechnology ,NF-κB ,Cell Line ,RAGE (receptor) ,Intensive care ,polycyclic compounds ,Pyroptosis ,Animals ,Medicine ,RNA, Messenger ,HMGB1 Protein ,Cecum ,Ligation ,Lung ,Cell Nucleus ,biology ,business.industry ,Lentivirus ,RAGE ,General Medicine ,respiratory system ,respiratory tract diseases ,Mice, Inbred C57BL ,Disease Models, Animal ,Protein Transport ,Myeloperoxidase ,biology.protein ,Cytokines ,Tumor necrosis factor alpha ,Inflammation Mediators ,business ,TP248.13-248.65 ,hormones, hormone substitutes, and hormone antagonists ,Dexmedetomidine ,Research Article ,Research Paper ,Signal Transduction ,Biotechnology - Abstract
Dexmedetomidine (DEX) has been reported to attenuate cecal ligation perforation (CLP)-stimulated acute lung injury (ALI) by downregulating HMGB1 and RAGE. This study aimed to further investigate the specific mechanisms of RAGE and its potential-related mechanisms of DEX on ALI models in vitro and in vivo. The in vitro and in vivo ALI models were established by lipopolysaccharide treatment in MLE-12 cells and CLP in mice, respectively. The effect of DEX on pathological alteration was investigated by HE staining. Thereafter, the myeloperoxidase (MPO) activity and inflammatory cytokine levels were respectively detected to assess the lung injury of mice using commercial kits. The expression levels of HMGB1, RAGE, NF-κB, and pyroptosis-related molecules were detected by RT-qPCR and Western blot. HE staining showed that lung injury, increased inflammatory cell infiltration, and lung permeability was found in the ALI mice, and DEX treatment significantly attenuated lung tissue damage induced by CLP. The MPO activity and inflammatory cytokines (TNF-α, IL-1β, and NLRP3) levels were also significantly reduced after DEX treatment compared with those in the ALI mice. Moreover, DEX activated the HMGB1/RAGE/NF-κB pathway and upregulated the pyroptosis-related proteins. However, the protective DEX effect was impaired by RAGE overexpression in ALI mice and MLE-12 cells. Additionally, DEX treatment significantly suppressed HMGB1 translocation from the nucleus region to the cytoplasm, and this effect was reversed by RAGE overexpression. These findings suggested that DEX may be a useful ALI treatment, and the protective effects on ALI mice may be through the inhibition of HMGB1/RAGE/NF-κB pathway and cell pyroptosis., Graphical abstractDexmedetomidine (DEX) has protective effects on acute lung injury (ALI) in vitro and in vivo. The possible mechanisms may be closely associated with inflammatory response, caspase-1-mediated cell pyroptosis, and high-mobility group protein 1 (HMGB1)/receptor for advanced glycation end products (RAGE)/nuclear factor-κB pathway. Moreover, DEX could promote the HMGB1 translocation from the cytoplasm to the nucleus in lipopolysaccharide-activated MLE-12 cells, whereas the action of RAGE overexpression was opposite.
- Published
- 2021
39. Curcumin protection against ultraviolet-induced photo-damage in Hacat cells by regulating nuclear factor erythroid 2-related factor 2
- Author
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Runxiang Li, Huilan Zhu, Miaojian Wan, Huiyan Deng, Huaping Li, Quan Chen, and Bihua Liang
- Subjects
Keratinocytes ,skin ,Cell Survival ,NF-E2-Related Factor 2 ,Ultraviolet Rays ,Apoptosis ,Bioengineering ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Antioxidants ,Superoxide dismutase ,chemistry.chemical_compound ,ultraviolet ,medicine ,HaCaT Cells ,Humans ,oxidative stress ,curcumin ,Cell Proliferation ,Cell Nucleus ,biology ,integumentary system ,Cell growth ,Chemistry ,photo-damage ,General Medicine ,respiratory system ,Molecular biology ,Heme oxygenase ,HaCaT ,nuclear factor erythroid 2-related factor 2 ,Cytoprotection ,Catalase ,biology.protein ,Curcumin ,Oxidative stress ,TP248.13-248.65 ,Research Article ,Research Paper ,Biotechnology - Abstract
Curcumin suppressed ultraviolet (UV) induced skin carcinogenesis and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. However, whether curcumin protects skin injury caused by UV is still unknown. A vitro model was established and curcumin effects on Hacat cells were detected. Nrf2 was knocked down in Hacat cells to verify the Nrf2 role in the protective effect of curcumin. Results indicated that ultraviolet A (UVA) (or ultraviolet B (UVB)) irradiation would lead to decreased cell proliferation, increased cell apoptosis, decreased catalase, heme oxygenase 1, and superoxide dismutase expression, and increased levels of protein carbonylation and malondialdehyde (p
- Published
- 2021
40. Nucleo-cytoplasmic RNA distribution responsible for maintaining neuroinflammatory microenvironment
- Author
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Jianhua Peng, Xiancheng Qiu, Yuyan Liao, Chenghao Kuang, Long Gu, Lifang Zhang, Shigang Yin, Xi Kong, Yong Jiang, Ghosh Dipritu, Qianke Tao, Zheng Bao, and Yijing He
- Subjects
Cytoplasm ,Hemorrhage ,Biology ,RNA Transport ,Cell Line ,Mice ,medicine ,Animals ,Molecular Biology ,Gene ,Neuroinflammation ,Cell Nucleus ,Regulation of gene expression ,Microglia ,Gene Expression Profiling ,Computational Biology ,RNA ,Cell Biology ,Subcellular localization ,Antisense RNA ,Cell biology ,Disease Models, Animal ,Gene Ontology ,medicine.anatomical_structure ,Cellular Microenvironment ,Neuroinflammatory Diseases ,RNA, Long Noncoding ,Disease Susceptibility ,Research Paper - Abstract
Subcellular localization of transcripts is highly associated with regulation of gene expression, synthesis of protein, and also the development of the human brain cortex. Although many mechanisms are prevalent in the occurrence of neuroinflammation, the mechanisms based on differences in subcellular localization of transcripts have not been explored. To characterize the dynamic profile of nuclear and cytoplasmic transcripts during the progress of haemorrhage-induced neuroinflammation, we isolated nucleo-cytoplasmic RNA fractions of oxyhaemoglobin (oxy-Hb) treated microglia cells and sequenced both fractions. We discovered that cytoplasmic retained genes were the major forces to maintain the neuroinflammatory microenvironment with 10 hub genes and 40 conserved genes were identified. Moreover, antisense RNA Gm44096 and lincRNA Gm47270, which co-expressed with a crowd of inflammatory genes in the cytoplasm, were discovered as regulatory strategies for sustaining the neuroinflammatory microenvironment. Thus, our study provides a new perspective on understanding haemorrhage-induced neuroinflammation and also reveals a mechanism of lncRNA responsible for maintaining the neuroinflammatory microenvironment.
- Published
- 2021
41. The plant nuclear lamina proteins NMCP1 and NMCP2 form a filamentous network with lateral filament associations
- Author
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Kaien Fujino, Kiyoshi Masuda, and Riku Hikida
- Subjects
0106 biological sciences ,NMCP2 ,NMCP1 ,Physiology ,Plant Science ,macromolecular substances ,Immunofluorescence ,01 natural sciences ,Protein filament ,03 medical and health sciences ,Nuclear Matrix-Associated Proteins ,stimulated emission depletion microscopy ,super-resolution microscopy ,parasitic diseases ,medicine ,Coiled-coil protein ,natural sciences ,Intermediate filament ,030304 developmental biology ,Plant Proteins ,Cell Nucleus ,0303 health sciences ,filamentous network ,medicine.diagnostic_test ,Chemistry ,Super-resolution microscopy ,AcademicSubjects/SCI01210 ,technology, industry, and agriculture ,food and beverages ,Cell Biology ,self-assembly ,Nuclear matrix ,Research Papers ,Lamins ,Chromatin ,Biophysics ,Nuclear lamina ,Lamin ,nuclear lamina ,010606 plant biology & botany - Abstract
Super-resolution microscopy revealed that the plant nuclear lamina proteins NMCP1 and NMCP2 organize into filamentous networks with filament bundles., Plant genomes lack genes encoding intermediate filament proteins, including lamins; however, functional lamin analogues are presumed to exist in plants. Plant-specific coiled-coil proteins, that is, nuclear matrix constituent proteins (NMCPs), are the most likely candidates as the structural elements of the nuclear lamina because they exhibit a lamin-like domain arrangement. They are exclusively localized at the nuclear periphery and have functions that are analogous to those of lamins. However, their assembly into filamentous polymers has not yet been confirmed. In this study, we examined the higher-order structure of NMCP1 and NMCP2 in Apium graveolens cells by using stimulated emission depletion microscopy combined with immunofluorescence cell labelling. Our analyses revealed that NMCP1 and NMCP2 form intricate filamentous networks, which include thick segments consisting of filament bundles, forming a dense filamentous layer extending across the nuclear periphery. Furthermore, the outermost chromatin distribution was found to be in the nucleoplasm-facing region of the nuclear lamina. Recombinant Daucus carota NMCP1 with a His-tag produced in Escherichia coli refolded into dimers and self-assembled into filaments and filament bundles. These results suggest that NMCP1 and NMCP2 organize into the nuclear lamina by forming a filamentous network with filament bundles that localize at the nuclear periphery.
- Published
- 2021
42. Challenges of Using Expansion Microscopy for Super‐resolved Imaging of Cellular Organelles
- Author
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Christoffer Lagerholm, Christian Eggeling, Silvia Galiani, Dominic Waithe, Wolfgang Schliebs, Katharina Reglinski, Ralf Erdmann, and Maximilian Büttner
- Subjects
cell organelles ,Matrix (biology) ,010402 general chemistry ,01 natural sciences ,Biochemistry ,law.invention ,Very Important Paper ,STED microscopy ,Confocal microscopy ,law ,Microscopy ,Organelle ,Peroxisomes ,Humans ,bioorganic chemistry ,Molecular Biology ,Polyacrylamide gel electrophoresis ,Cellular compartment ,Cell Nucleus ,Microscopy, Confocal ,Full Paper ,010405 organic chemistry ,Chemistry ,Cell Membrane ,Organic Chemistry ,Full Papers ,Peroxisome ,Mitochondria ,Molecular Imaging ,0104 chemical sciences ,HEK293 Cells ,Microscopy, Fluorescence ,peptides ,Biophysics ,Molecular Medicine ,expansion microscopy - Abstract
Expansion microscopy (ExM) has been successfully used to improve the spatial resolution when imaging tissues by optical microscopy. In ExM, proteins of a fixed sample are crosslinked to a swellable acrylamide gel, which expands when incubated in water. Therefore, ExM allows enlarged subcellular structures to be resolved that would otherwise be hidden to standard confocal microscopy. Herein, we aim to validate ExM for the study of peroxisomes, mitochondria, nuclei and the plasma membrane. Upon comparison of the expansion factors of these cellular compartments in HEK293 cells within the same gel, we found significant differences, of a factor of above 2, in expansion factors. For peroxisomes, the expansion factor differed even between peroxisomal membrane and matrix marker; this underlines the need for a thorough validation of expansion factors of this powerful technique. We further give an overview of possible quantification methods for the determination of expansion factors of intracellular organelles, and we highlight some potentials and challenges., In Expansion Microscopy (ExM) subcellular structures are imaged in isotropically expanded fixed samples, consequently allowing to resolve enlarged subcellular structures, otherwise hidden to standard microscopy. Upon comparison of the expansion factors of different cellular compartments in cells within the same gel, we found significant differences in expansion factors of a factor of above 2.
- Published
- 2020
43. Oxidative stress and signaling through EGFR and PKA pathways converge on the nuclear transport factor RanBP1.
- Author
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Kodiha M, Azad N, Chu S, Crampton N, and Stochaj U
- Subjects
- Active Transport, Cell Nucleus, Cyclic AMP-Dependent Protein Kinases metabolism, Oxidative Stress, ErbB Receptors metabolism, Oxidants metabolism, Cell Nucleus metabolism, ran GTP-Binding Protein metabolism
- Abstract
Nuclear protein trafficking requires the soluble transport factor RanBP1. The subcellular distribution of RanBP1 is dynamic, as the protein shuttles between the nucleus and cytoplasm. To date, the signaling pathways regulating RanBP1 subcellular localization are poorly understood. During interphase, RanBP1 resides mostly in the cytoplasm. We show here that oxidative stress concentrates RanBP1 in the nucleus, and our study defines the underlying mechanisms. Specifically, RanBP1's cysteine residues are not essential for its oxidant-induced relocation. Furthermore, our pharmacological approaches uncover that signaling mediated by epidermal growth factor receptor (EGFR) and protein kinase A (PKA) control RanBP1 localization during stress. In particular, pharmacological inhibitors of EGFR or PKA diminish the oxidant-dependent relocation of RanBP1. Mutant analysis identified serine 60 and tyrosine 103 as regulators of RanBP1 nuclear accumulation during oxidant exposure. Taken together, our results define RanBP1 as a target of oxidative stress and a downstream effector of EGFR and PKA signaling routes. This positions RanBP1 at the intersection of important cellular signaling circuits., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier GmbH.. All rights reserved.)
- Published
- 2024
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44. Nucleocytoplasmic shuttling of the GPN-loop GTPase Gpn3 is regulated by serum and cell density in MCF-12A mammary cells.
- Author
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Peña-Gómez SG, Cristóbal-Mondragón GR, Vega-Palomo CR, Mora-García M, Félix-Pérez T, Rebolloso-Gómez Y, Calera MR, and Sánchez-Olea R
- Subjects
- Active Transport, Cell Nucleus, Proteasome Endopeptidase Complex metabolism, Cell Count, GTP Phosphohydrolases metabolism, Cell Nucleus metabolism
- Abstract
The best-known function of the essential GPN-loop GTPase Gpn3 is to contribute to RNA polymerase II assembly, a prerequisite for its nuclear targeting. Although this process occurs in the cytoplasm, we have previously shown that Gpn3 enters the cell nucleus before being polyubiquitinated. Here, we show that inhibiting Crm1-mediated nuclear export with leptomycin B, or the proteasome with MG132, caused the nuclear accumulation of recombinant and endogenous Gpn3 in MCF-12A cells. When added simultaneously, leptomycin B and MG132 had an additive effect. Analysis of Gpn3 primary sequence revealed the presence of at least five nuclear export sequence (NES) motifs, with some having a higher exposure to the solvent in the GTP-bound than GDP-bound state in a Gpn3 structural model. Inactivation of any of these NESes led to some degree of Gpn3 nuclear accumulation, although mutating NES1 or NES3 had the more robust effect. MCF-12A cells expressing exclusively a NES-deficient version of Gpn3R-Flag proliferated slower than cells expressing Gpn3R-Flag wt, indicating that nuclear export is important for Gpn3 function. Next, we searched for physiological conditions regulating Gpn3 nucleocytoplasmic shuttling. Interestingly, whereas Gpn3R-Flag was both nuclear and cytoplasmic in low-density growing MCF-12A cells, it was exclusively cytoplasmic in high-density areas. Furthermore, Gpn3R-Flag was cytoplasmic, mostly perinuclear, in sparse but starved MCF-12A cells, and serum-stimulation caused a rapid, although transient, Gpn3R-Flag nuclear accumulation. We conclude that Gpn3 nucleocytoplasmic shuttling is regulated by cell density and growth factors, and propose that Gpn3 has an unknown nuclear function positively linked to cell growth and/or proliferation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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45. Nuclear expression of VDR and AHR is mutually exclusive in glandular cells in endometriosis
- Author
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Livio Casarini, Viktoria von Schönfeldt, Francesco De Pascali, Manuela Simoni, Sven Mahner, Christina Kuhn, and Udo Jeschke
- Subjects
0301 basic medicine ,Histology ,AHR ,Response element ,Endometriosis ,Biology ,Endometrium ,Calcitriol receptor ,03 medical and health sciences ,Immunohistochemistry ,Nuclear receptors ,VDR ,0302 clinical medicine ,Basic Helix-Loop-Helix Transcription Factors ,medicine ,Humans ,Receptor ,Molecular Biology ,Cell Nucleus ,Original Paper ,030219 obstetrics & reproductive medicine ,Epithelial Cells ,Cell Biology ,medicine.disease ,Aryl hydrocarbon receptor ,Medical Laboratory Technology ,030104 developmental biology ,medicine.anatomical_structure ,Receptors, Aryl Hydrocarbon ,Nuclear receptor ,Cancer research ,biology.protein ,Receptors, Calcitriol ,Female - Abstract
The vitamin D receptor (VDR) and aryl hydrocarbon receptor (AHR) are two nuclear receptors that exert their effects by binding with ligands and forming a molecular complex. These complexes translocate to the nucleus and activate the expression of a series of genes which have a response element to VDR or AHR. Both receptors have been identified in the pathogenesis of endometriosis, a common disease characterized by the formation of endometrium-like tissue in ectopic zones. Despite numerous therapies, there is no definitive cure for endometriosis at the pharmacological level. Our study aims to describe the location and the expression of VDR and AHR at the protein level. For this purpose, an evaluation was performed using tissue from the three normal phases of the endometrium (proliferative, early, and late secretory) and in endometriosis by immunohistochemistry, using anti-VDR and anti-AHR antibodies. We demonstrate that in the nuclei of glandular cells in endometriosis, the expression of VDR and AHR is mutually exclusive—when the expression of one receptor is high, the other one is low—suggesting a possible target in the treatment of endometriosis. We also identify a significant change in the expression of glandular cytoplasmic AHR between the proliferative and late secretory endometrium. Supplementary Information The online version contains supplementary material available at 10.1007/s00418-021-02005-9.
- Published
- 2021
46. PTEN nuclear translocation enhances neuronal injury after hypoxia-ischemia via modulation of the nuclear factor-κB signaling pathway
- Author
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Chunyan Zhang, Jing Zhao, Li Hou, Lin Jiang, Linlin Yin, and Ling He
- Subjects
Aging ,MAP Kinase Signaling System ,Phosphatase ,Brain damage ,Rats, Sprague-Dawley ,Ischemia ,medicine ,PTEN ,Tensin ,Animals ,Phosphorylation ,Cells, Cultured ,Cell Nucleus ,Neurons ,biology ,ERK1/2 ,Kinase ,Chemistry ,oxygen and glucose deprivation ,NF-kappa B ,PTEN Phosphohydrolase ,Cell Biology ,brain damage ,Cell Hypoxia ,Cell biology ,Oxygen ,hypoxia-ischemia ,Protein Transport ,phosphatase and tensin homolog deletion from chromosome 10 ,Glucose ,nervous system ,Apoptosis ,biology.protein ,medicine.symptom ,Signal transduction ,Research Paper ,Signal Transduction - Abstract
The occurrence of hypoxia-ischemia (HI) in the developing brain is closely associated with neuronal injury and even death. However, the underlying molecular mechanism is not fully understood. This study was designed to investigate phosphatase and tensin homolog (PTEN) nuclear translocation and its possible role in rat cortical neuronal damage following oxygen-glucose deprivation (OGD) in vitro. An in vitro OGD model was established using primary cortical neurons dissected from newborn Sprague-Dawley rats to mimic HI conditions. The PTENK13R mutant plasmid, which contains a lysine-to-arginine mutation at the lysine 13 residue, was constructed. The nuclei and cytoplasm of neurons were separated. Neuronal injury following OGD was evidenced by increased lactate dehydrogenase (LDH) release and apoptotic cell counts. In addition, PTEN expression was increased and the phosphorylation of extracellular signal-regulated kinase 1/2 (p-ERK1/2) and activation of nuclear factor kappa B (NF-κB) were decreased following OGD. PTENK13R transfection prevented PTEN nuclear translocation; attenuated the effect of OGD on nuclear p-ERK1/2 and NF-κB, apoptosis, and LDH release; and increased the expression of several anti-apoptotic proteins. We conclude that PTEN nuclear translocation plays an essential role in neuronal injury following OGD via modulation of the p-ERK1/2 and NF-κB pathways. Prevention of PTEN nuclear translocation might be a candidate strategy for preventing brain injury following HI.
- Published
- 2021
47. Racemization in cataractous lens from diabetic and aging individuals: analysis of Asp 58 residue in αA-crystallin
- Author
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Jiao Qi, Wenwen He, Keke Zhang, Xiangjia Zhu, and Yi Lu
- Subjects
Male ,medicine.medical_specialty ,Aging ,genetic structures ,lens ,Cataract ,Lens protein ,Isomerism ,Crystallin ,Cortex (anatomy) ,Internal medicine ,Diabetes mellitus ,crystallin ,Lens, Crystalline ,medicine ,Humans ,aspartyl residue ,Racemization ,Aged ,Cell Nucleus ,Aspartic Acid ,Arc (protein) ,diabetes ,Chemistry ,Cell Biology ,medicine.disease ,Crystallins ,eye diseases ,medicine.anatomical_structure ,Endocrinology ,Solubility ,racemization ,Cataractous lens ,Female ,sense organs ,Nucleus ,Research Paper - Abstract
Cataract is the leading cause of visual impairment globally. Racemization of lens proteins may contribute to cataract formation in aging individuals. As a special type of age-related cataract (ARC), diabetic cataract (DC) is characterized by the early onset of cortical opacification and finally developed into a mixed type of cortical and nuclear opacification. We compared racemization of Asp 58 residue, a hotspot position in αA-crystallin, from the cortex and nucleus of diabetic and age-matched senile cataractous lenses, by identifying L-Asp/L-isoAsp/D-Asp/D-isoAsp by mass spectrometry. Compared to nondiabetic cataractous lenses, DC lenses showed a significantly increased cortex/nucleus ratio of D-Asp 58, which originated primarily from an increased percentage of D-Asp 58 in the lens cortex of DC. Moreover, patients diagnosed with diabetes for over 10 years showed a lower cortex/nucleus ratio of D-isoAsp 58 in the lens compared with those who had a shorter duration of diabetes, which originated mainly from an increased percentage of D-isoAsp 58 in the lens nucleus of DC with increasing time of hyperglycemia. Further analysis confirmed decreased protein solubility in diabetic cataractous lenses. The different racemization pattern in DC may be distinguished from ARC and influence its phenotype over the protracted duration of diabetes.
- Published
- 2021
48. Inhibition of CXCR2 plays a pivotal role in re-sensitizing ovarian cancer to cisplatin treatment
- Author
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Nayara G. Tessarollo, Raquel Maria da Silva Graça Almeida, Luísa Pereira, Diandra Zipinotti dos Santos, Ian Victor Silva, Patrícia Mesquita, Isabella dos Santos Guimarães, Diana Pádua, Paulo Cilas Morais Lyra-Junior, Leticia Batista Azevedo Rangel, Taciane B. Henriques, Ana Luísa Amaral, and Bruno Cavadas
- Subjects
Aging ,Epithelial-Mesenchymal Transition ,Cell Survival ,MAP Kinase Signaling System ,Chemokine CXCL2 ,Chick Embryo ,Receptors, Interleukin-8B ,Phosphatidylinositol 3-Kinases ,Chemokine receptor ,Cell Line, Tumor ,medicine ,Animals ,Humans ,tumor microenvironment ,Neoplasm Invasiveness ,Interleukin 8 ,CXC chemokine receptors ,Cell Proliferation ,Cell Nucleus ,Ovarian Neoplasms ,Cisplatin ,Tumor microenvironment ,CXCR2 ,Neovascularization, Pathologic ,Chemistry ,TOR Serine-Threonine Kinases ,chemoresistance ,Cell Biology ,medicine.disease ,Survival Analysis ,Neoplasm Proteins ,CXCL2 ,Drug Resistance, Neoplasm ,Tumor progression ,high grade serous ovarian cancer ,Cancer research ,Female ,Ovarian cancer ,Proto-Oncogene Proteins c-akt ,Research Paper ,medicine.drug - Abstract
cDNA microarray data conducted by our group revealed overexpression of CXCL2 and CXCL8 in ovarian cancer (OC) microenvironment. Herein, we have proven that the chemokine receptor, CXCR2, is a pivotal molecule in re-sensitizing OC to cisplatin, and its inhibition decreases cell proliferation, viability, tumor size in cisplatin-resistant cells, as well as reversed the overexpression of mesenchymal epithelium transition markers. Altogether, our study indicates a central effect of CXCR2 in preventing tumor progression, due to acquisition of cisplatin chemoresistant phenotype by tumor cells, and patients’ high lethality rate. We found that the overexpression of CXCR2 by OC cells is persistent and anomalously confined to the cellular nuclei, thus pointing to an urge in developing highly lipophilic molecules that promptly permeate cells, bind to and inhibit nuclear CXCR2 to fight OC, instead of relying on the high-cost genetic engineered cells.
- Published
- 2021
49. SARS-CoV-2 main protease suppresses type I interferon production by preventing nuclear translocation of phosphorylated IRF3
- Author
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Sin-Yee Fung, Dong-Yan Jin, Huayue Lin, Man Lung Yeung, and Kam-Leung Siu
- Subjects
medicine.medical_treatment ,viruses ,NSP5 ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,TANK-binding kinase 1 ,Interferon ,Chlorocebus aethiops ,medicine ,Animals ,Humans ,Phosphorylation ,skin and connective tissue diseases ,Molecular Biology ,Vero Cells ,Ecology, Evolution, Behavior and Systematics ,Coronavirus 3C Proteases ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,Protease ,Chemistry ,SARS-CoV-2 ,fungi ,virus diseases ,COVID-19 ,SARS-CoV ,Cell Biology ,biochemical phenomena, metabolism, and nutrition ,IRF3 ,Type I interferon production ,Cell biology ,Protein Transport ,type I interferons ,Interferon Type I ,Vero cell ,Interferon Regulatory Factor-3 ,3C-like protease ,Interferon type I ,Developmental Biology ,medicine.drug ,Research Paper - Abstract
Suppression of type I interferon (IFN) response is one pathological outcome of the infection of highly pathogenic human coronaviruses. To effect this, severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 encode multiple IFN antagonists. In this study, we reported on the IFN antagonism of SARS-CoV-2 main protease NSP5. NSP5 proteins of both SARS-CoV and SARS-CoV-2 counteracted Sendai virus-induced IFN production. NSP5 variants G15S and K90R commonly seen in circulating strains of SARS-CoV-2 retained the IFN-antagonizing property. The suppressive effect of NSP5 on IFN-β gene transcription induced by RIG-I, MAVS, TBK1 and IKKϵ suggested that NSP5 likely acts at a step downstream of IRF3 phosphorylation in the cytoplasm. NSP5 did not influence steady-state expression or phosphorylation of IRF3, suggesting that IRF3, regardless of its phosphorylation state, might not be the substrate of NSP5 protease. However, nuclear translocation of phosphorylated IRF3 was severely compromised in NSP5-expressing cells. Taken together, our work revealed a new mechanism by which NSP5 proteins encoded by SARS-CoV and SARS-CoV-2 antagonize IFN production by retaining phosphorylated IRF3 in the cytoplasm. Our findings have implications in rational design and development of antiviral agents against SARS-CoV-2.
- Published
- 2021
50. The functional impact of nuclear reorganization in cellular senescence
- Author
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Azucena Rocha, Audrey Dalgarno, and Nicola Neretti
- Subjects
Cell Nucleus ,AcademicSubjects/SCI01140 ,Review Paper ,0303 health sciences ,nuclear organization ,aging ,epigenome ,Cellular senescence ,Functional impact ,Genomics ,General Medicine ,Biology ,Biochemistry ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,cellular senescence ,chromatin ,Molecular Biology ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
Cellular senescence is the irreversible cell cycle arrest in response to DNA damage. Because senescent cells accumulate with age and contribute to chronic inflammation, they are promising therapeutic targets for healthspan extension. The senescent phenotype can vary depending on cell type and on the specific insults that induce senescence. This variability is also reflected in the extensive remodeling of the genome organization within the nucleus of senescent cells. Here, we give an overview of the nuclear changes that occur in different forms of senescence, including changes to chromatin state and composition and to the three-dimensional organization of the genome, as well as alterations to the nuclear envelope and to the accessibility of repetitive genomic regions. Many of these changes are shared across all forms of senescence, implicating nuclear organization as a fundamental driver of the senescent state and of how senescent cells interact with the surrounding tissue.
- Published
- 2021
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