HP1γ sets the biological age of the intestinal epithelium

ABSTRACTAltered RNA maturation and decay have well-documented effects on tissue longevity. Yet, RNA metabolism is poorly investigated in the gut epithelium, a constantly renewing tissue particularly challenged by ageing. We found that inactivation of the epigenetic regulator HP1γ in the mouse gut epithelium results in accelerated ageing associated with both ectopic expression of ribosomal RNAs and accumulation of miss-spliced messenger RNAs. A consequence of the latter is the production of progerin, a spliced product of the LMNA gene associated with the Hutchinson Gilford Syndrome. Production of progerin transcript increased naturally in the mouse ageing gut, in correlation with a reduced HP1γ expression. Thus, progerin is a candidate marker of aging of the gut epithelium, while HP1γ inactivation emerges as a new model for accelerated aging in this tissue.

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Effects of Accelerated Aging Period of Time at 180°C on Tensile Property of Plain Woven Fabric/Epoxy Resin Laminated Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.182-183.76 ◽

2012 ◽

Vol 182-183 ◽

pp. 76-79 ◽

Cited By ~ 1

Author(s):

Lei Lei Song ◽

Quan Rong Liu ◽

Jia Lu Li

Keyword(s):

Tensile Strength ◽

Carbon Fiber ◽

Epoxy Resin ◽

Laminated Composites ◽

Accelerated Aging ◽

Woven Fabric ◽

Accelerated Ageing ◽

Time Intervals ◽

Composite Samples

In this paper, carbon fiber reinforced resin matrix composites were produced by stacking eight pieces of carbon fiber woven plain fabric and subjected to accelerated ageing. Accelerated ageing was carried out in oven at 180°C for three different time intervals (60 hours, 120 hours and 180 hours). The influence of different ageing time intervals at 180°C on tensile properties of laminated composites was examined, compared with the composites without aging. The appearance and damage forms of these laminated composites were investigated. The results revealed that the tensile strength of the laminates declined significantly after long term accelerated aging at 180°C. The average tensile strengths of composite samples aged 60 hours, 120 hours, and 180 hours period of time at 180°C are 80.36%, 79.82%, 76.57% of average tensile strength of composite samples without aging, respectively. The high temperature accelerated aging makes the resin macromolecular structure in the composites changed, and then the adhesive force between fiber bundles and resin declines rapidly which result in the tensile strength of composites aged decrease. This research provides a useful reference for long term durability of laminated/epoxy resin composites.

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Differential localization of villin and fimbrin during development of the mouse visceral endoderm and intestinal epithelium

Development ◽

10.1242/dev.106.2.407 ◽

1989 ◽

Vol 106 (2) ◽

pp. 407-419 ◽

Cited By ~ 1

Author(s):

R.M. Ezzell ◽

M.M. Chafel ◽

P.T. Matsudaira

Keyword(s):

Intestinal Epithelium ◽

Actin Filaments ◽

Early Embryo ◽

Actin Binding ◽

Common Mechanism ◽

Apical Surface ◽

Visceral Endoderm ◽

Apical Cytoplasm ◽

Gut Epithelium ◽

Microfilament Bundles

The apical surface of transporting epithelia is specially modified to absorb nutrients efficiently by amplifying its surface area as microvilli. Each microvillus is supported by an underlying core of bundled actin filaments. Villin and fimbrin are two actin-binding proteins that bundle actin filaments in the intestine and kidney brush border epithelium. To better understand their function in the assembly of the cytoskeleton during epithelial differentiation, we examined the pattern of villin and fimbrin expression in the developing mouse using immunofluorescence and immunoelectron microscopy. Villin is first detected at day 5 in the primitive endoderm of the postimplantation embryo and is later restricted to the visceral endoderm. By day 8.5, villin becomes redistributed to the apical surface in the visceral endoderm, appearing in the gut at day 10 and concentrating in the apical cytoplasm of the differentiating intestinal epithelium 2–3 days later. In contrast, fimbrin is found in the oocyte and in all tissues of the early embryo. In both the visceral endoderm and gut epithelium, fimbrin concentrates at the apical surface 2–3 days after villin; this redistribution occurs when the visceral endoderm microvilli first contain organized microfilament bundles and when microvilli first begin to appear in the gut. These results suggest a common mechanism of assembly of the absorptive surface of two different tissues in the embryo and identify villin as a useful marker for the visceral endoderm.

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Crucial and Overlapping Roles of Six1 and Six2 in Craniofacial Development

Journal of Dental Research ◽

10.1177/0022034519835204 ◽

2019 ◽

Vol 98 (5) ◽

pp. 572-579 ◽

Cited By ~ 8

Author(s):

Z. Liu ◽

C. Li ◽

J. Xu ◽

Y. Lan ◽

H. Liu ◽

...

Keyword(s):

Neural Crest ◽

Ectopic Expression ◽

Mandibular Condyle ◽

Neural Crest Cell ◽

Messenger Rnas ◽

Developmental Defects ◽

Facial Cleft ◽

Frontonasal Dysplasia ◽

Morphogenetic Protein ◽

Crest Cell

SIX1 and SIX2 encode closely related transcription factors of which disruptions have been associated with distinct craniofacial syndromes, with mutations in SIX1 associated with branchiootic syndrome 3 (BOS3) and heterozygous deletions of SIX2 associated with frontonasal dysplasia defects. Whereas mice deficient in Six1 recapitulated most of the developmental defects associated with BOS3, mice lacking Six2 function had no obvious frontonasal defects. We show that Six1 and Six2 exhibit partly overlapping patterns of expression in the developing mouse embryonic frontonasal, maxillary, and mandibular processes. We found that Six1 –/– Six2 –/– double-mutant mice were born with severe craniofacial deformity not seen in the Six1 –/– or Six2 –/– single mutants, including skull bone agenesis, midline facial cleft, and syngnathia. Moreover, whereas Six1 –/– mice exhibited partial transformation of maxillary zygomatic bone into a mandibular condyle-like structure, Six1 –/–Six2 +/– mice exhibit significantly increased penetrance of the maxillary malformation. In addition to ectopic Dlx5 expression at the maxillary-mandibular junction as recently reported in E10.5 Six1 –/– embryos, the E10.5 Six1 –/– Six2 +/– embryos showed ectopic expression of Bmp4, Msx1, and Msx2 messenger RNAs in the maxillary-mandibular junction. Genetically inactivating 1 allele of either Ednra or Bmp4 significantly reduced the penetrance of maxillary malformation in both Six1 –/– and Six1 –/– Six2 +/– embryos, indicating that Six1 and Six2 regulate both endothelin and bone morphogenetic protein-4 signaling pathways to pattern the facial structures. Furthermore, we show that neural crest–specific inactivation of Six1 in Six2 –/– embryos resulted in midline facial cleft and frontal bone agenesis. We show that Six1 –/– Six2 –/– embryos exhibit significantly reduced expression of key frontonasal development genes Alx1 and Alx3 as well as increased apoptosis in the developing frontonasal mesenchyme. Together, these results indicate that Six1 and Six2 function partly redundantly to control multiple craniofacial developmental processes and play a crucial neural crest cell–autonomous role in frontonasal morphogenesis.

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A role for CdxA in gut closure and intestinal epithelia differentiation

Development ◽

10.1242/dev.120.2.253 ◽

1994 ◽

Vol 120 (2) ◽

pp. 253-263 ◽

Cited By ~ 2

Author(s):

A. Frumkin ◽

G. Pillemer ◽

R. Haffner ◽

N. Tarcic ◽

Y. Gruenbaum ◽

...

Keyword(s):

Protein Expression ◽

Intestinal Epithelium ◽

Alimentary Canal ◽

Gradual Increase ◽

Homeobox Gene ◽

Early Embryogenesis ◽

Main Site ◽

Intestinal Epithelia ◽

Gut Epithelium ◽

Tight Linkage

CdxA is a homeobox gene of the caudal type that was previously shown to be expressed in the endoderm-derived gut epithelium during early embryogenesis. Expression of the CDXA protein was studied during intestine morphogenesis from stage 11 (13 somites) to adulthood in the chicken. The CDXA protein can be detected during all stages of gut closure, from stage 11 to 5 days of incubation, and is mainly localized to the intestinal portals, the region where the splanchnopleure is undergoing closure. In this region, which represents the transition between the open and closed gut, the CDXA protein is restricted to the endoderm-derived epithelium. At about day 5 of incubation, the process of formation of the previllous ridges begins, which marks the beginning of the morphogenesis of the villi. From this stage to day 11 expression of CDXA is localized to the epithelial lining of the intestine. In parallel, a gradual increase in CDXA protein expression begins in the mesenchyme that is close in proximity to the CDXA-positive endoderm. Maximal CDXA levels in the mesenchyme are observed at day 9 of incubation. During days 10 and 11 CDXA levels in the mesenchyme remain constant, and by day 12 CDXA becomes undetectable in these cells and the epithelium again becomes the main site of expression. From day 12 of incubation until adulthood the CDXA protein is present in the intestinal epithelium. Until day 18 of incubation expression can be detected along the whole length of the villus with a stronger signal at the tip. With hatching the distribution along the villi changes so that the main site of CDXA protein expression is at the base of the villi and in the crypts. The transient expression of CDXA in the mesenchyme between days 5 and 11 may be related to the interactions taking place between the mesenchyme and the epithelium that ultimately result in the axial specification of the alimentary canal and the differentiation of its various epithelia. The main CDXA spatial distribution during morphogenesis suggests a tight linkage to the formation and differentiation of the intestinal epithelium itself. CDXA appears to play a role in the morphogenetic events leading to closure of the alimentary canal. During previllous ridge formation the CDXA protein is transiently expressed in the mesenchymal cells thought to provide instructive interactions for the regionalization and differentiation of the gut epithelium.(ABSTRACT TRUNCATED AT 400 WORDS)

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Seed Vigour Tests to Estimate Seedling Emergence in Cress (Lepidium sativum L.) Seed Lots

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha47311453 ◽

2019 ◽

Vol 47 (3) ◽

Author(s):

Ibrahim DEMIR ◽

Burcu B. KENANOGLU ◽

Eren ÖZDEN

Keyword(s):

Electrical Conductivity ◽

Seedling Emergence ◽

Accelerated Aging ◽

Lepidium Sativum ◽

Accelerated Ageing ◽

Digital Object Identifier ◽

Seed Vigour ◽

Significance Levels ◽

Radicle Emergence ◽

Lepidium Sativum L

This work was carried out to estimate field and controlled room seedling emergence potential through seed vigour tests in cress (Lepidium sativum L.) seeds. Early radicle emergence percentages after 12 (RE12h), 24 (RE24h) and 36 (RE36h) hours of germination test, mean germination time, accelerated aging (45 °C, 100% RH, 24 h), electrical conductivity (EC) of soaking water (40 ml, 50 seeds, 20 °C), after 16 hours (EC16h) and 24 hours (EC24h), and EC16h and EC24h after accelerated ageing (AA, 45 °C, 100% RH, 24h) were tested as vigour tests in ten commercial seed lots of cress. Standard laboratory germination ranged between 88 and 93%. Seeds were sown on two occasions in field and controlled room conditions, and seedling emergence percentages were determined after 30 days in the soil and 14 days in the controlled room. Seedling emergence ranged between 67 and 85% and 59 and 83% in the first and second sowings in the field. These values were 75 and 92% in controlled room sowing. Vigour tests were correlated to seedling emergence potential at various significance levels but RE24h and EC16h showed the highest correlation coefficient values (p < 0.001) in all three sowing conditions as r = 0.879-0.988 in RE24h, and r = 0.902-0.962 in EC16h. Results indicated that early radicle emergence percentages after 24 hours (RE24h) and electrical conductivity value after 16 hours (EC16h) can be successfully used to estimate the seedling emergence potential of cress seeds in field and controlled room conditions. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

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Moist Heat Accelerated Aging Test of Naturally Aged Paper by Suspension Method

Restaurator International Journal for the Preservation of Library and Archival Material ◽

10.1515/res-2013-0006 ◽

2013 ◽

Vol 34 (2) ◽

Cited By ~ 1

Author(s):

Kang Lee ◽

Masamitsu Inaba

Keyword(s):

Degradation Rate ◽

Accelerated Aging ◽

Accelerated Ageing ◽

Natural Ageing ◽

Cellulose Chain ◽

Accelerated Aging Test ◽

Tear Index ◽

Aging Test ◽

Degradation Rate Constant ◽

Physical And Chemical

AbstractThis research was planned to clarify the relationship between natural ageing and accelerated ageing of paper using naturally aged paper. First, samples of paper which had deteriorated over time for 130 to 80 years were artificially aged at 80°C, 65% RH, and their physical and chemical changes were investigated. Oxalic acid contained in the samples before accelerated ageing increased, while glycolic acid showed a tendency to decrease. This means that accelerated ageing test did not simulate the chemical processes occurring during natural ageing in a straight forward manner. On the other hand, paper in which many organic acids had accumulated by natural ageing showed larger degradation rate indicators of tear index and burst index i.e. initial degradation rate constant divided by initial tear index or initial burst index before accelerated ageing and discolouration rate. That of values of the degradation rate indicators of tear index and burst index and the discolouration rate showed good correlation with the number of cellulose chain breaks. However, the number of cellulose chain breaks is not simply correlated with the concentration of hydrogen ion which is an index of the acidic hydrolysis of paper. Oxidation contributes to the rate of cellulose chain breaks.

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Metode Pengusangan Cepat dengan Larutan Etanol untuk Pengujian Vigor Daya Simpan Benih Caisin (Brassica rapa L. cv. grup Caisin)

Jurnal Hortikultura Indonesia ◽

10.29244/jhi.7.3.165-175 ◽

2016 ◽

Vol 7 (3) ◽

pp. 165

Author(s):

Aisa Amanah ◽

Maryati Sari ◽

Abdul Qadir

Keyword(s):

Key Words ◽

Brassica Rapa ◽

Accelerated Aging ◽

Seed Storage ◽

Aluminum Foil ◽

Seed Vigor ◽

Coefficient Of Determination ◽

Accelerated Ageing ◽

Aluminium Foil ◽

Chemical Aging

ABSTRACT The objective of this study was to obtain effective duration in accelerated aging method with soaking the seed in 20% liquid ethanol which could estimate vigor related to storability of caisin seed during 3 and 6 months storage. There were five commercial caisin seed lots used in this study. The lots have different initial vigor. This research was conducted in two separate experiments. The first experiment was conducted to study deterioration of caisin seeds stored in aluminum foil pouches for 3 and 6 months at ambient room. The second experiment was conducted to study the effect of chemical aging duration, i.e 30, 60, 90, 120, 150, and 180 minutes moistened (12 hours imbibed) seed soaking in liquid ethanol 20%. Both of experiments were arranged in completely nested design. Germination of seeds after soaking in 20% liquid ethanol for 90 minutes was positively correlated with germination of seeds after storage for 3 and 6 months with coefficient of corellation = 0.87 and 0.88. Both coefficient of corellations were close to 1 which showed that the germination of seeds after accelerated ageing with soaking in 20% liquid ethanol could estimate seed vigor related to storability. Vigor related to storability of caisin seed after 3 months could be predicted by the equation y = 56.04+0.36x with the coefficient of determination 77.00%. While after 6 months it can be predicted by the equation y = 62.72+0.38x with the coefficient of determination 74.90%. Y variable indicates germination of caisin seed after storage while the x variable indicates germination of caisin seed after soaking in 20% liquid ethanol for 90 minutes. Key words: deterioration, devigoration, longevity, seed storage, viability ABSTRAK Penelitian ini dilakukan untuk mendapatkan waktu perendaman ke dalam etanol 20% yang tepat pada metode pengusangan cepat kimia yang dapat menduga vigor daya simpan benih caisin setelah penyimpanan 3 dan 6 bulan. Benih yang digunakan berasal dari lima lot benih komersial dengan vigor awal yang berbeda. Penelitian terdiri atas 2 percobaan terpisah. Percobaan 1 adalah penyimpanan benih caisin dalam kemasan aluminium foil selama 3 dan 6 bulan pada ruang suhu kamar. Percobaan 2 yaitu pengusangan cepat kimia dengan merendam benih caisin yang telah dilembabkan selama 12 jam ke dalam larutan etanol 20% selama 30, 60, 90, 120, 150, dan 180 menit. Kedua percobaan menggunakan rancangan acak lengkap tersarang. Daya berkecambah benih setelah pengusangan melalui perendaman etanol 20% selama 90 menit berkorelasi positif dengan daya berkecambah benih setelah penyimpanan selama 3 dan 6 bulan. Nilai koefisien korelasi pada 3 dan 6 bulan setelah simpan adalah 0.87 dan 0.88. Kedua koefisien korelasi tersebut mendekati 1 yang menunjukkan bahwa daya berkecambah benih setelah pengusangan cepat dengan etanol 20% dapat menduga vigor daya simpan. Vigor daya simpan benih caisin setelah 3 bulan simpan dapat diduga dengan persamaan y = 62.72+0.38x dengan nilai koefisien determinasi sebesar 77.00%, sementara setelah 6 bulan dapat diduga dengan persamaan y = 56.04+0.36x dengan nilai koefisien determinasi sebesar 74.90%. Peubah y menunjukkan daya berkecambah setelah penyimpanan sedangkan x menunjukkan daya berkecambah setelah pengusangan melalui perendaman etanol 20% selama 90 menit. Kata kunci: daya simpan, deteriorasi, devigorasi, penyimpanan benih, viabilitas

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Competition within Introns: Splicing Wins over Polyadenylation via a General Mechanism

Acta Naturae ◽

10.32607/20758251-2013-5-4-52-61 ◽

2013 ◽

Vol 5 (4) ◽

pp. 52-61 ◽

Cited By ~ 3

Author(s):

M. V. Tikhonov ◽

P. G. Georgiev ◽

O. G. Maksimenko

Keyword(s):

Rna Processing ◽

General Mechanism ◽

Messenger Rnas ◽

Genomic Context ◽

Reporter System ◽

Gene Overlapping ◽

A Chain ◽

Rna Maturation ◽

The Relationship ◽

Polyadenylation Signals

Most eukaryotic messenger RNAs are capped, spliced, and polyadenylated via co-transcriptional processes that are coupled to each other and to the transcription machinery. Coordination of these processes ensures correct RNA maturation and provides for the diversity of the transcribed isoforms. Thus, RNA processing is a chain of events in which the completion of one event is coupled to the initiation of the next one. In this context, the relationship between splicing and polyadenylation is an important aspect of gene regulation. We have found that cryptic polyadenylation signals are widely distributed over the intron sequences of Drosophila melanogaster. As shown by analyzing the distribution of genes arranged in a nested pattern, where one gene is fully located within an intron of another gene, overlapping of putative polyadenylation signals is a fairly common event affecting about 17% of all genes. Here we show that polyadenylation signals are silenced within introns: the poly(A) signal is utilized in the exonic but not in the intronic regions of the transcript. The transcription does not end within the introns, either in a transient reporter system or in the genomic context, while deletion of the 5'-splice site restores their functionality. According to a full Drosophila transcriptome analysis, utilization of intronic polyadenylation signals occurs very rarely and such events are likely to be inducible. These results confirm that the transcription apparatus ignores premature polyadenylation signals for as long as they are intronic.

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Accelerated ageing of paper: effect of lignin content and humidity on tensile properties

Heritage Science ◽

10.1186/s40494-021-00611-3 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Edyta Małachowska ◽

Marcin Dubowik ◽

Piotr Boruszewski ◽

Piotr Przybysz

Keyword(s):

Tensile Properties ◽

Ph Value ◽

Lignin Content ◽

Accelerated Aging ◽

Strength Properties ◽

Accelerated Ageing ◽

Hydrothermal Aging ◽

Paper Properties ◽

Factors Affecting ◽

Before And After

AbstractPaper degradation menaces the useful lifetime of books, manuscripts, and works on paper during storage, circulation, and display in libraries, archives, and museums. Severe damages such as embrittlement, decay, and mold often occur to the paper that might threaten to lose cultural heritage. However, the shelf life of papers stored in suitable conditions can be extended by hundreds of years. The most important external factors affecting the deterioration of paper-based materials include, in particular, changes in temperature and air humidity. In this study, the effects of accelerated aging under different conditions, including substantially different relative humidity, were considered relative to the strength properties of the paper sheets. These include the mechanical strength, such as breaking length, tear resistance, and bursting strength of the paper samples before and after dry heat aging and hydrothermal aging. Samples with various content of lignin produced in neutral pH were examined to exclude the adverse influence of acidity on paper properties. The results indicate that impact of moisture on tensile properties and pH-value of paper is much greater than the effect of increased temperature. The results of this work are intended to consolidate and expand the theoretical foundation and provide technical support for the conservators and library staff on the storage of paper cultural relics.

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