SEARCH · PubMed Health

Results for “fate restriction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2025

Ovarian development is driven by early spatiotemporal priming of the coelomic epithelium.

Ovarian organogenesis requires the coordinated specification of supporting and steroidogenic cell lineages from multipotent coelomic epithelium (CE) progenitors. A longstanding question is whether the CE contains transcriptionally distinct, spatially organized progenitor subpopulations with predetermined lineage biases, or whether specification into supporting and steroidogenic lineages occurs only after delamination and integration into the bipotential gonad. The developmental origins of granulosa cells and the emergence of ovarian steroidogenic/stromal progenitors (SPs) also remain poorly defined. Here, we show that CE cells covering the fetal mouse ovary are transcriptionally heterogeneous and spatially organized into subdomains already primed toward supporting or steroidogenic fates. CE priming is dynamic, with transient coexistence of supporting- and steroidogenic-biased CE progenitors before resolving into a predominantly supporting-biased CE. Local delamination of these primed cells seeds intragonadal niches where pre-granulosa cells and SPs mirror the spatio-temporal arrangements of CE-primed progenitors. We further demonstrate a dual origin for the supporting lineage, with granulosa cells deriving from both the CE and supporting-like cells (SLCs). In parallel, we show that SPs arise from steroidogenic-primed CE cells, expand to represent 52% of ovarian somatic cells at birth, persist into adulthood and contribute to both theca and steroidogenic stromal cells. Together, these findings reveal transcriptionally and spatially distinct CE subpopulations that shape somatic lineage emergence with important implications for ovarian pathophysiology.

Ovarian development↗

PubMed2026

Transcription regulation of cell fate plasticity - from embryonic development to tissue regeneration.

Cell fate plasticity refers to the capacity of cells sharing the same genome to alter, reverse, or reconfigure their identity under physiological, pathological, or experimental conditions. This property underlies embryonic development, cellular reprogramming, and tissue regeneration, but becomes progressively restricted as lineage identity is stabilized. Embryonic development represents an intrinsic process of fate transitions, whereas reprogramming and regeneration reveal how differentiated cells can dedifferentiate or transdifferentiate under specific conditions. Across these contexts, plasticity is governed by multilayered regulatory networks involving transcription factors, epigenetic regulators, cofactors, and the core transcription machinery. Robust regulatory programs stabilize cell identity, whereas stochastic fluctuations in gene expression and chromatin state can prime cells for fate transitions, adding a tunable dimension to plasticity control. In this review, we synthesize recent advances in the regulation of cell fate plasticity across development, reprogramming, and regeneration, highlighting how transcription factors, epigenetic modifications, transcriptional cofactors, and core transcription machinery cooperate to control cell fate decisions and plasticity.

Animals↗

PubMed1978

Transduction of a bacterial gene into mammalian cells.

The transduction of an Escherichia coli gene into mammalian cells is described. A supressor tRNA gene was linked to a simian virus 40 (SV40) vector in vitro and the recombinant was used to transfect rat embryo cells and monkey kidney cells. The hybrid SV40 genome, SV40-su+ III, retained genetic information required for autonomous replication and cellular transformation and had a 1300-base-pair DNA segment in the late gene region (between the restriction endonuclease sits Hpa II at 0.735 and EcoRI at 0/1.0 on the SV40 genetic map) replaced by an 870-base-pair bacterial DNA segment containing the suppressor tRNA gene, su+ III (tRNATyrsu+III). The structure and fate of the SV40-su+III chimera were determined by DNA reassociation kinetic analysis and restriction enzyme cleavage of the total cellular DNA from transformed rat embryo cells and persistently infected monkey cells. Hybridization with radiolabeled probes specific for vector (SV40) or su+III DNA sequences revealed primarily nonintegrated or free hybrid genomes. In cloned lines of both cell types, the bacterial DNA segment was recovered intact, as judged by the length of the segment excised by restriction endonucleases and its ability to hybridize to the radiolabeled bacterial DNA probe and not to the SV40 probe.

Cell Line↗

PubMed2026

Measurable Residual Disease and the Unresolved Biology of Leukemic Stem Cells.

Measurable residual disease (MRD) testing has transformed the management of hematologic cancers by enabling detection of residual malignant cells after therapy. Current approaches rely on qPCR and next-generation sequencing to monitor leukemia-associated somatic mutations, while multiparameter flow cytometry identifies aberrant leukemic immunophenotypes. Although these methods provide valuable prognostic and therapeutic information, MRD negativity remains an imperfect surrogate for cure. Most MRD platforms evaluate CD45+, rapidly dividing leukemic populations and fail to detect quiescent cells that may survive cytotoxic therapies which efficiently target proliferating hematopoietic cells. Relapse frequently occurs despite deep molecular remission, suggesting persistence of rare leukemic stem cells (LSCs) that are intrinsically resistant to chemotherapy and targeted therapies. The paradox of relapse despite molecular remission could be explained by the presence of very small embryonic-like stem cells (VSELs) which are pluripotent, quiescent stem cells sitting at the top of cellular hierarchy in multiple adult tissues including bone marrow. A pluripotent VSEL divides through asymmetrical cell division to give rise to two cells of different sizes and fates, smaller cell is to self-renew while the bigger is lineage-restricted and tissue-committed progenitor which undergoes extensive epigenetic changes, divides rapidly and undergoes clonal expansion before further differentiation. Dysfunctions of VSELs initiate both solid and hematologic cancers. Based on this view, somatic mutations monitored during MRD assessment possibly represent downstream consequences of clonal expansion rather than the initiating drivers of disease persistence. Thus, exclusive monitoring of somatic mutations and CD45 + leukemic populations possibly overlook rare, small-sized, CD45- VSELs that contribute to therapeutic resistance and relapse.

Humans↗

PubMedDate not supplied

[A different interpretation of the Oedipus complex].

Is mans fate irrevocable predetermined or have we a certain amout of free will? We assume, that although restricted by his own developed character, and given circumstances, man has a choice and is capable to influence his destiny. According to Freud our actions and behaviour are often unconsciously motivated and frequently incomprehensible for ourselves. They are then independent of our "will" and capacity of decision--making. Freud observes rightly the ambivalence of seelings between father and son, mother and daughter and regards this as the essential factor for the character-formation of the developing child. However his interpretation that these feelings are always based on libidinous wishes and jealousy seems to the author too farfetched and not fully proved in all cases. In the author's opinion the basic problem of life must be an insolvable one and that is the problem of death. Seen from the father's point of view, the son, on one hand represents the only solution for continuation of his life, the only possibility of victory over death, on the other hand however, he will substitute him one day, make him superfluous and eventually take his place. A similar process takes place between mother and daughter who on one hand would like to enjoy the beauty and success of her daughter (whom she regards as her biological continuation)--by whom however she feels as well pushed aside and made older on the other hand. The Problem, how to vanquish death and the wish for continuation of our existance, the resistance against extinction and replacement by someone else, is of fundamental and inescapable importance. If we understand this, we will find a more profound explicaiton of ambivalent feelings between parents and children. The aim of human development should be, to find the right way, how to satisfy our justified urges in accepting the limits of our capacities and possibilities within the framework of reality.--In doing so, our creative capabilities and our desires for change and progress should not be inhibited. The acceptance of our Self, of the reality of life and of our limitations includes however also the acceptance of death. This inside therefore will have its positive effect also on the development of the ambivalent feelings between parents and children, which we could handle better, if we know and understand their meaning.

Aggression↗

PubMed1979

Role of methylation in the modification and restriction of chloroplast DNA in Chlamydomonas.

The different metabolic paths followed by homologous chloroplast DNAs of maternal and paternal origins in zygotes of Chlamydomonas were examined by prelabeling parental cells, before mating them, with [3H]adenine, [3H]thymidine, and [3H]deoxycytidine. Within 6 hr after mating, maternal chloroplast DNA was extensively methylated to 5-methylcytosine and its bouyant density decreased. Paternal chloroplast DNA was largely degraded. Some radioactivity from deoxycytidine of maternal origin reappeared in thymine, and residual paternal DNA contained radioactivity in a base tentatively identified as uracil. These results confirm and extend our previous findings and support our hypothesis that modification (methylation) and restriction enzymes determine maternal inheritance of chloroplast DNA and that the two parental DNAs have different metabolic fates within the zygote.

Adenine↗

PubMed1978

The transfer and stable integration of the HSV thymidine kinase gene into mouse cells.

Treatment of mutant mouse cells (Ltk-) deficient in thymidine kinase with Bam I restriction endonuclease-cleaved HSV-1 DNA results in the appearance of numerous surviving colonies which stably express thte tk+ phenotype. Through a series of electrophoretic fractionations in concert with transfection assays, we isolated a 3.4 kb fragment which contains the thymidine kinase gene and which alone is competent in the biochemical transformation of Ltk- cells. In this report, we have examined the distribution of tk sequences in the DNA of several transformed clones following stable gene transfer. A series of complementary experiments involving reassociation kinetics in solution and annealings with tk DNA to restriction-cleaved cellular DNA following electrophoresis and transfer to filters allow us to make the following general conclusions concerning the fate of the tk gene in all clones examined: the tk gene is present in all cells at a frequency of one copy per chromosomal complement; the tk gene is stably integrated in the DNA of all transformants; and integration is not site-specific and occurs at different loci in the DNA of all transformants examined. The existence of a single active tk gene in tk+ transformants now facilitates an analysis of the sequence organization of tk- mutant cells and provides a useful model system for studies on the transfer of cellular genes.

Cell Line↗

PubMed2024

TGF-β controls alveolar type 1 epithelial cell plasticity and alveolar matrisome gene transcription in mice.

Premature birth disrupts normal lung development and places infants at risk for bronchopulmonary dysplasia (BPD), a disease disrupting lung health throughout the life of an individual and that is increasing in incidence. The TGF-β superfamily has been implicated in BPD pathogenesis, however, what cell lineage it impacts remains unclear. We show that TGFbr2 is critical for alveolar epithelial (AT1) cell fate maintenance and function. Loss of TGFbr2 in AT1 cells during late lung development leads to AT1-AT2 cell reprogramming and altered pulmonary architecture, which persists into adulthood. Restriction of fetal lung stretch and associated AT1 cell spreading through a model of oligohydramnios enhances AT1-AT2 reprogramming. Transcriptomic and proteomic analyses reveal the necessity of TGFbr2 expression in AT1 cells for extracellular matrix production. Moreover, TGF-β signaling regulates integrin transcription to alter AT1 cell morphology, which further impacts ECM expression through changes in mechanotransduction. These data reveal the cell intrinsic necessity of TGF-β signaling in maintaining AT1 cell fate and reveal this cell lineage as a major orchestrator of the alveolar matrisome.

Humans↗

PubMedDate not supplied

The saccharin controversy.

Saccharin and its salts are the most extensively consumed artificial sweeteners in the United States today. The current controversy about the risks of their use to human health has surfaced from research findings that report an increased incidence of cancer, primarily of the urinary bladder, in certain animal species and man chronically exposed to these agents. The April 1977 proposal by the Food and Drug Administration to restrict use of saccharin was based on these investigations. The intense public response against any ban has led to Congressional deliberations over the fate of saccharin during the present moratorium and information-gathering period. Since diabetic patients are among the principal users of this compound, it appears timely to review the evidence for and against its carcinogenic potential.

Adolescent↗

PubMed1979

Truth from genetic illusion: the transference and the fate of the infantile neurosis.

I have attempted to show that the relative decline of genetic interpretation and reconstruction in modern analysis is a result of historical and methodological problems built into an enduring and developmentally restricted model of the infantile neurosis which has descended more or less intact into our time, a model still parochialized to the phallic-oedipal period and its prototypic oedipal conflict. Mounting direct evidences from both longitudinal developmental studies and child analyses, as well as from the more indirect evidences inferred from the genetic reconstructions of adult analyses, all argue for a developmental reconsideration of infantile neurosis to include preoedipal determinants. I have also asked that we include a measure of postoedipal determinancy as well in any such reconsideration, insofar as latency is the developmental condition for the usual resolution of the infantile neurosis. It must be emphasized that to argue for preoedipal determinancy is to say that problems with early object relatedness and early narcissistic pathology deform the oedipal conflict and its phase-adequate resolution. It does not suggest that narcissistic conflict can replace an oedipal one as the organizing conflict of the infantile neurosis during the phallic-oedipal period. The continuing parochialization of the infantile neurosis to the phallic-oedipal period has been perpetuated in great part by a technical legacy which has tended to restrict reconstructions of the infantile neurosis to the more discursively recoverable libidinal events of that period, and to exclude its preoedipal and aggressive determinants which are more apt to be expressed through the nondiscursive modes of the transference through its acts and self states.

Consciousness↗

PubMed1975

Metabolic fates of herbicides in animals.

Many general aspects of the subjects were covered by the two previous reviews. Important recent changes in handling harvested cereal grains include more bulk transportation--particularly containerisation,processing closer to the site of production, resistance topesticides in many granivorous insects and the alarmingly unpredictable cross-resistance spectra in some sppecies, and a hardening in the attitude of governments and the food industry to the use of pesticides. Pesticide manufacturers arecurrently restricting their involvement in the stored grain area. The market is small and unpredictable due to crossresistance. However, a number of interesting and potentially useful compounds have appeared, notable )(bio) resmethrin, pirimiphos-methyl, andDursban-methyl, which reflect attempts to provide somewhat morepersistent compounds under adverse storage conditionnnnns than ismalathion--currently the most widely-used control agent.Inevitably, there is interest also in alternative methods, of control, from the obvious physical methods (drying, cooling, air-tight storage)to use of pheromones, insect hormone anaogues, and larvicides, all of which may have some future potential...

Amides↗

PubMed2026

Target-Site Selection by Transcription Factors: Roles of DNA, Chromatin, and Cofactor-Mediated Regulation.

Transcription factors (TFs) are sequence-specific DNA-binding proteins that regulate gene-expression programs and cell fate. The ability of a defined combination of four TFs to reprogram differentiated cells into induced pluripotent stem cells illustrates the powerful role of TFs in determining cellular identity. However, TFs usually recognize short and degenerate DNA motifs of approximately 6-12 base pairs, generating thousands to millions of potential motif matches in mammalian genomes. In living cells, TFs occupy only a restricted subset of these sites, indicating that motif presence alone is insufficient for functional target selection. Several layers of regulation contribute to this selective occupancy, including DNA methylation, nucleosome organization, histone modifications, chromatin remodeling, TF oligomerization, TF availability and localization, and cofactors that regulate DNA-binding domains. This review outlines how DNA/chromatin features and TF-centered mechanisms contribute to target-site selection. The principal aim is to highlight DNA-binding domain-directed cofactor regulation as an underappreciated mechanism that modulates TF-DNA binding and may help explain selective genomic occupancy.

Target-site selection↗

PubMed1975

[Hormonal treatment of breast cancer from surgical point of view (author's transl)].

At present the best results in treating breast cancer of stage I and II appear to be achieved by surgery alone. As an alternative method preference should be given to the so-called classical radical mastectomy. Restriction or widening of operative management may be useful in some cases, but the indication is problematic. There is a high risk of applying appropriate procedures to inappropriate patients. In radical mastectomy the incidence of errors and complications comes within reasonable limits. On the contrary, in stage III additional treatment is well justified. At this stage, surgery alone gives poor results. The fate of stage III patients first of all depends on the presence or absence of metastases; therefore, preference should be given to systemic additional treatment, but on the basis of individualized tried measures. Polypragmasia and blind systemic treatment are to be avoided. The time schedule of such additional treatment are to be avoided. The time schedule of such additional treatment has to be established, by controlled clinical trials. From these considerations, the following requirements can be formulated: 1. improvement of the oncologic level 2. centralisation in oncologic treatment and diagnostics 3. enlargement of existing or creation of new facilities for bi-chemical and other testing, and for scientific investigation at the oneologic centers.

Breast Neoplasms↗

PubMed1979

Carbon tetrachloride induced proliferation of tight junctions in the rat liver as revealed by freeze-fracturing.

Application of carbon tetrachloride produced a progressive proliferation of tight junctions in the rat liver. This system proved to be rapid and highly reproducable and affords the opportunity for tracing the fate of tight junctions in freeze-fracture replicas, facilitating investigations on their formation and function. Beginning on day one carbon tetrachloride treatments resulted in the progressive loosening and fragmentation of the junctional meshwork. After three to four days the membrane outside the zonulae occludentes was extensively filled with proliferated discrete junctional elements often forming complex configurations. From the fifth day on the zonulae occludentes were restricted again predominantly around the bile canaliculus margins. But the junctional meshwork of the zonulae occludentes remained loosened in comparison to those in the control rats. It could be shown that tight junction proliferation on the lateral surface of the plasmalemma occurred both through de novo formation from discrete centers of growth by addition of intramembranous particles and through reorganization of preexistent junctional strands of the fragmented zonulae occludentes bodies. Whereas the large gap junctions close associated with the zonulae occludentes remained more or less unaffected during the experiments, small gap junctions increased in number after five days and were located at the margin or in the tight junction domain. It is assumed that the degeneration of the tight junctions served as a pool for intramembranous particles which form the gap junctions. The results of these observations are discussed in relation to those obtained in other systems.

Animals↗

PubMed1977

Fate and distribution of the herbicides 2,4-dichlor-phenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in the dogfish shark.

1. The urinary and biliary excretion, tissue distribution and metabolism of 14C-labelled 2,4-dichloro- or 2,4,5-trichloro-phenoxyacetic acids (2,4-D or 2,4,5-T) were measured in dogfish sharks, Squalus acanthias. 2. Both herbicides are extensively metabolized (greater than 90%) to the corresponding taurine conjugates, and are excreted predominantly via the urine, where ca. 70% of the administered dose appears within 4-6 days after treatment. 3. The highest tissue levels of 2,4-D or 2,4,5-T were found in liver and kidney. Penetration of both herbicides into the CNS was restricted. 4. Plasma elimination was rapid and the 0.5 for either phenoxyacetic acid was less than 45 min. Similarly, rapid clearance as seen from renal tissue. Final t0.5 values for muscle were about 2-3 days while the major organ showing 2,4-D or 2,4,5-T retention was the liver, where t0.5 values were about 5 days for both the herbicides. 5. The overall pharmacokinetics in the dogfish shark for these herbicides resembled those seen in some mammals.

2,4,5-Trichlorophenoxyacetic Acid↗

PubMed1975

The fate of N-dansyl-L-phenylalanine in the cerebrospinal fluid after intraventricular and intracisternal injection: a comparative fluorescence microscopic and analytical study.

Absorption, accumulation and release of N-Dansyl-L-phenylalanine (DPA) through the ependyma, plexus choriodei and brain parenchyma after intraventricular and intracisternal injection was examined at different postinjection intervals by fluorescence microscopy. The following results were obtained: 1. After intraventricular injection, DPA is rapidly absorbed from the ependyma and plexus choriodei in all ventricles and subsequently disappears from the various points of the ventricles at different times. DPA is no longer evident in the ependyma after 40 min and the plexus after 90 min. Aborption and storage occur primarily in the dopaminergic centers of the brain. This stage begins 5 min p.i. attains a maximum after 40 min and is maintained up to 180 min p.i. 2. If DPA is administered intracisternally, fluorescence is initially restricted to the ependyma and choroid plexus of the fourth ventricle and to the wall of the aquaeduct. Only at 5-10 min p.i. are rostral ventricular portions labelled. Passage of the amino acid out of the ventricle only occurs to a limited extent. 40 min after intracisternal injection, DPA is no longer demonstrable in the ependyma and plexus or brain parenchyma. 3. Intrathecally administered DPA appears in the periglomerular tubules of the kidney as well 2.5 min p.i. and is stored there for up to 40 min. The kidney medulla remains free of fluorescence. 4. DPA injected into the CSF is protein-bound.

Animals↗

PubMedDate not supplied

The fate of bacteria in frozen red cells.

Units of blood were intentionally contaiminated with suspensions of either Aerobacter aerogenes, Escherichia coli, Bacillus subtilis, Enterobacter cloacae, Pseudomonas aeruginosa, Sarcina lutea, Seratia marcesens, Staphylococcus epidermidis, Streptococcus faecalis, Paracolabacterum aerogenoides (Enterobacter hafriae), Mima polymorpha or Acinetobacter- calcoaceticus. When inoculation was made prior to glycerolization, the subsequent glycerolization, freezing, thawing, and deglycerolization resulted in roughly a two log reduction in the number of bacteria. When inoculation was made with a final concentration of between 10(1) and 10(5) organisms per milliliter, immediately following deglycerolization or following washing without glycerolization and freezing, no increase in the number of bacteria was seen after 72 hours storage at 4 C. Three of the 12 organisms studied decreased in number during 72 hours of storage. These data suggest that the current 24-hour limit on the post-thaw storage of frozen red blood cells may be unnecessarily restrictive.

Bacteria↗

PubMed2026

Distributed Clonal Deletion Prevents Autoimmune Disease Progression.

Self-reactive B cells are generated during normal development and can acquire increased pathogenicity through activation-induced cytidine deaminase (AID)-mediated diversification following activation. Clonal deletion is thought to eliminate these cells, yet how deletion is distributed across developmental and activation stages to prevent autoimmune disease remains unclear. Here, we show that clonal deletion is enforced through temporally distinct mitochondrial apoptosis (MOMP) checkpoints that differentially regulate autoreactive B cell fate and disease progression. Using conditional Bcl-2 expression to inhibit MOMP either before or after B cell activation, we find that early inhibition permits the survival and maturation of autoreactive B cells after peripheral egress, expanding the pool of cells available for activation. These cells subsequently undergo AID-dependent diversification, producing class-switched IgG autoantibodies with expanded antigen breadth that target a wider range of self-antigens and drive lethal, female-biased autoimmune disease characterized by complement activation and kidney pathology. In contrast, inhibition of MOMP only after activation allows the accumulation of germinal center, switched memory, and plasma cells and promotes autoantibody production, but results in more restricted IgG autoreactivity, limited complement activation and limited tissue damage, and normal survival. Notably, early MOMP inhibition does not expand immature bone marrow B cells, indicating that a major clonal deletion checkpoint operates in the periphery rather than during initial B cell generation. Together, these findings support a Distributed Clonal Deletion Model in which early checkpoints restrict the entry of autoreactive B cells into diversification pathways, while later checkpoints limit the persistence of diversified autoreactive clones, thereby constraining autoimmune disease progression.

Journal Article↗