Abstract：
:The ascidian Ciona intestinalis has a short life span and powerful regeneration capacities. The regeneration of the oral siphon (OS) involves wound healing, blastema formation, cell proliferation, and replacement of 8 oral pigment organs (OPO), the latter via differentiation and migration of stem/precursor cells from localized niches in the siphon. The restoration of OPO pattern during OS regeneration occurs with a high degree of accuracy through three successive cycles of amputation. It is shown here that oral siphons of the largest and oldest members of a wild Ciona population do not completely regenerate their siphons after amputation. The loss of regeneration capacity was accompanied by reduced cell proliferation. In contrast to arrested OS outgrowth, the stem/precursor cells responsible for OPO replacement "over-differentiate" after OS amputation in the oldest animals, the typical number of OPO is increased from 8 to 12-16, and malformed OPO are produced. Also in contrast to younger animals, the oldest animals of the population show arrested OPO development after two consecutive cycles of amputation and regeneration. We conclude that there is a size and age threshold in Ciona after which the regenerative capacity of the OS is compromised due to effects of aging on cell proliferation.
journal_name
Mech Ageing Devjournal_title
Mechanisms of ageing and developmentauthors
Jeffery WRdoi
10.1016/j.mad.2012.08.003subject
Has Abstractpub_date
2012-09-01 00:00:00pages
629-36issue
9-10eissn
0047-6374issn
1872-6216pii
S0047-6374(12)00145-5journal_volume
133pub_type
杂志文章abstract：:The effect of aging on patterns of food intake and nutrient selection was investigated using a longitudinal study. Male (n = 10) and female (n = 10) Wistar-Lou rats from 4 to 28 months of age were repeatedly submitted to a macronutrient self-selection (S-S) regimen while controls were maintained under a standard chow ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(98)00013-x
更新日期：1998-07-15 00:00:00
abstract：:Detailed structural, mutational, and biochemical analyses of human FEN1/DNA complexes have revealed the mechanism for recognition of 5' flaps formed during lagging strand replication and DNA repair. FEN1 processes 5' flaps through a previously unknown, but structurally elegant double-stranded (ds) recognition/single s...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/j.mad.2011.11.009
更新日期：2012-04-01 00:00:00
abstract：:The various phases of homo- and heteroclonal encounters between stolons of Podocoryne carnea M. Sars have been studied with the light and electron microscope. The first clone-unspecific actions and reactions to an imminent encounter between the outgrowing tip of stolon and the subterminal part of an opposed homologous...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(83)90045-3
更新日期：1983-03-01 00:00:00
abstract：:The paper of Kitani cited in the title has raised an apparent contradiction regarding the validity of certain aspects of the membrane hypothesis of aging (MHA). He collected data showing that a number of detoxifying liver enzyme activities, although decline with age in male Fischer 344 rats, remain at an unchanged lev...
journal_title：Mechanisms of ageing and development
pub_type： 评论,杂志文章
doi：10.1016/s0047-6374(01)00237-8
更新日期：2001-06-01 00:00:00
abstract：:Food restriction is known to ameliorate many of the adverse physiologic effects of age. In this study, we have examined the effect of food restriction on the induction of the gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK) in liver and kidney following a 12-h fasting period in young (6 month) and old (...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(98)00075-x
更新日期：1998-09-01 00:00:00
abstract：:We have developed a cell model for loss of differentiated gene expression in cellular aging. Over long periods in culture, bovine adrenocortical cells lose expression of a specialized gene, steroid 17 alpha-hydroxylase. The decline in expression of 17 alpha-hydroxylase in mass cultures and clones of bovine adrenocorti...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(91)90115-g
更新日期：1991-04-01 00:00:00
abstract：:We have developed a novel method to examine the translational fidelity of mammalian ribosomes in vitro, where protamine mRNA was used as a template. This method enabled us to determine frequency of misrecognition of purine bases at the second position of arginine codons (AGR/AAR) in the mRNA. Using this method the fid...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(83)90002-7
更新日期：1983-05-01 00:00:00
abstract：:Longevity regulatory genes include the Forkhead transcription factor FOXO, in addition to NAD-dependent histone deacetylase silent information regulator 2 (Sir2). The FOXO/DAF-16 family of transcription factors constitute an evolutionarily conserved subgroup within a larger family known as winged helix or Forkhead tra...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2004.09.021
更新日期：2005-01-01 00:00:00
abstract：:Skeletal muscle ageing is characterized by faulty degenerative/regenerative processes that promote the decline of its mass, strength, and endurance. In this study, we used a transcriptional profiling method to better understand the molecular pathways and factors that contribute to these processes. To more appropriatel...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2009.11.001
更新日期：2010-01-01 00:00:00
abstract：INTRODUCTION:Our objective was to study the impact of an identical additional stress on male and female mortality with a quasi-experimental study design, using natural variations in summer mortality, including the massive heat wave that struck Europe in 2003. MATERIAL AND METHODS:The summer daily mortality rates of th...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2012.04.004
更新日期：2012-06-01 00:00:00
abstract：:The development and aging of the nucleolus and nucleus in layer V pyramidal cells in the hamster cerebrum were studied by light and electron microscopy. The nucleoli appeared in the newborn as occasional fibrillar masses adjacent to peripherally placed bodies of chromatin. By maturity, a single, generally central, nuc...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(81)90043-9
更新日期：1981-04-01 00:00:00
abstract：:The role of glucocorticosteroid and thyroid hormone and of glucagon and insulin in the pre- and postnatal developmental formation of carbamoyl-phosphate synthase, ornithine transcarbamoylase, arginase, glutamate dehydrogenase, tyrosine aminotransferase, glucose-6-phosphatase, hexokinase and glucokinase activities in r...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(81)90010-5
更新日期：1981-01-01 00:00:00
abstract：:We tested the hypothesis that Ca(2+)-activated myosin ATPase activity is lower in muscles of aged rats relative to muscles of young rats, independent of changes in myosin isoform expression. Myofibrils were prepared from permeabilized fibers of soleus, plantaris, and semimembranosus muscles of young (8-12 months) and ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2004.07.002
更新日期：2004-09-01 00:00:00
abstract：:Previous studies have suggested a possible relationship between the ubiquitin-proteasome pathway and some pathological manifestations of Alzheimer's disease (AD). This study investigated the possibility that the Abeta peptides interact with the ubiquitin-proteasome pathway inside neuronal cells. The ubiquitin-proteaso...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2005.07.006
更新日期：2005-12-01 00:00:00
abstract：:Motor neurons and ventral root motor fibres innervating extensor digitorum longus (EDL) muscle in rats of 0.5-3.5 months of age were studied by HRP-retrograde labelling and in vivo muscle tension recording, respectively. EDL nucleus size increased with age but motor neurons number and size did not change. Twitch and t...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(96)01839-8
更新日期：1996-12-20 00:00:00
abstract：:Thymic atrophy or thymus absence causes depressed thyroid-thymus axis (TTA) efficiency in old, young propyl-thiouracil (PTU) (experimental hypothyroidism) and in young-adult thymectomised (Tx) mice, respectively. Altered zinc turnover may be also involved in depressed TTA efficiency. Zinc turnover is under the control...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(01)00414-6
更新日期：2002-03-31 00:00:00
abstract：:In yeast, increasing the copy number of the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase Sir2 extends lifespan, which can be inhibited by nicotinamide (Nam), the end-product of Sir2-mediated NAD-breakdown. Furthermore, the yeast pyrazinamidase/nicotinamidase PNC-1 can extend yeast lifespan by converti...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2007.01.004
更新日期：2007-04-01 00:00:00
abstract：:The lifespan of the nematode, Caenorhabditis elegans, can be extended by mutations affecting components of the insulin-like growth factor (IGF) signaling cascade or by overexpression of SIR2, an NAD+-dependent protein deacetylase. The mammalian homologue of SIR2, Sirt1, has been shown to modulate the activity of FoxO,...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2005.04.006
更新日期：2005-10-01 00:00:00
abstract：:Morphometric comparison of freeze-fractured mitochondria in flight muscles of adult (37-day-old) and old (68-day-old) houseflies revealed a 28% decrease of cristae in the old flies. The major membrane change with age was an increase in the 90-120-A particles in the inner membrane external face concomitant with a loss ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(81)90095-6
更新日期：1981-06-01 00:00:00
abstract：:Many molecular chaperones are also known as heat shock proteins because they are synthesised in increased amounts after brief exposure of cells to elevated temperatures. They have many cellular functions and are involved in the folding of nascent proteins, the re-folding of denatured proteins, the prevention of protei...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2004.09.031
更新日期：2005-01-01 00:00:00
abstract：:We have previously reported that two or more different subpopulations of bone marrow stem cells exist in mice as determined by cycling status of day-8 and day-14 CFU-S in long term bromodeoxyuridine (BrdU) infusion studies. In the present report, comparisons between cycling of stem cell subpopulations in old and young...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(89)90069-9
更新日期：1989-07-01 00:00:00
abstract：:Chronic low-grade inflammation is involved in the pathogenesis of many disease conditions in humans and it is frequently quantified by measuring the blood concentration of C-reactive protein (CRP). Here we show that the CRP concentration in old people (nonagenarians) is, at least partially, genetically determined, and...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2007.07.004
更新日期：2007-10-01 00:00:00
abstract：:The mTOR deregulation has a role in chronic kidney disease including diabetic nephropathy. SIRT1 is an important participant in renal cytoprotective responses to aging and stress. However, whether both mTOR and SIRT1 are involved in high glucose-inducing mesangial cells (MCs) senescence still remains to be explored. H...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2012.04.005
更新日期：2012-06-01 00:00:00
abstract：:The bone marrow content, proliferative potential and proliferative activity of precursor cells for stromal fibroblast colony forming cells (CFC-F) were investigated in young and old CBA mice. The relationship between CFC-F and the number of bone marrow nucleated cells and granulocytic-macrophagal precursors (GM-CFC) w...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(90)90061-j
更新日期：1990-05-30 00:00:00
abstract：:In adult rats 3, 6 and 9 months post-orchidectomy performed at the age of 30 days the thymus weight, thymocyte yield and relative proportions of thymocyte subsets (delineated by expression of CD4/CD8 molecules and TCRalphabeta) were analyzed in order to elucidate a putative role of male gonadal hormones in the shaping...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(01)00399-2
更新日期：2002-02-01 00:00:00
abstract：:Caloric restriction has been extensively investigated as an intervention that both extends lifespan and delays age-related disease in mammals. In mice, much interest has centered on evaluating gene expression changes induced by caloric restriction (CR) in particular tissue types, but the overall systemic effect of CR ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2007.11.003
更新日期：2008-03-01 00:00:00
abstract：:We have developed a relatively rapid, safe and simple method for the quantification of sjTREC levels in samples of peripheral blood. The assay uses an image analysis package to measure the brightness of PCR product bands on an image of the standard agarose gel. Comparison of the brightness of the band with that obtain...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(00)00197-4
更新日期：2000-12-20 00:00:00
abstract：:Published data on age-related human biological functions are surveyed. For the many showing a linear decrease, regressions were calculated, or existing functions extrapolated, to yield an intercept on the abscissa. The values of chi(0), the age at which a function ceases, provide a tentative common means of comparison...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/0047-6374(93)90072-y
更新日期：1993-06-01 00:00:00
abstract：:Prostaglandin (PG) synthesis by human embryo lung fibroblasts in culture was determined with increasing population doubling. These cultures synthesized PGE2, PGF2 alpha, PGI2 (prostacyclin) and TXA2 (thromboxane A2) in response to fetal bovine serum or ascorbic acid. Changes in prostaglandin synthesis by these cells d...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(80)90063-9
更新日期：1980-04-01 00:00:00
abstract：:The general objective of this study was to examine the relationship between oxygen free radicals and the aging process. The rate of superoxide anion radical (O2.-) generation was measured in liver sub-mitochondrial particles from mouse, rat, rabbit, pig and cow, and in flight muscle sub-mitochondrial particles from th...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/0047-6374(89)90096-1
更新日期：1989-08-01 00:00:00
