-
IScience Jul 2023Although the formin-nucleated actomyosin cortex has been shown to drive the changes in cell shape that accompany animal cell division in both symmetric and asymmetric...
Although the formin-nucleated actomyosin cortex has been shown to drive the changes in cell shape that accompany animal cell division in both symmetric and asymmetric cell divisions, the mitotic role of cortical Arp2/3-nucleated actin networks remain unclear. Here using asymmetrically dividing neural stem cells as a model system, we identify a pool of membrane protrusions that form at the apical cortex of neuroblasts as they enter mitosis. Strikingly, these apically localized protrusions are enriched in SCAR, and depend on SCAR and Arp2/3 complexes for their formation. Because compromising SCAR or the Arp2/3 complex delays the apical clearance of Myosin II at the onset of anaphase and induces cortical instability at cytokinesis, these data point to a role for an apical branched actin filament network in fine-tuning the actomyosin cortex to enable the precise control of cell shape changes during an asymmetric cell division.
PubMed: 37434695
DOI: 10.1016/j.isci.2023.107129 -
Current Biology : CB Nov 2023Geometry is a fundamental attribute of biological systems, and it underlies cell and tissue dynamics. Cell geometry controls cell-cycle progression and mitosis and thus...
Geometry is a fundamental attribute of biological systems, and it underlies cell and tissue dynamics. Cell geometry controls cell-cycle progression and mitosis and thus modulates tissue development and homeostasis. In sharp contrast and despite the extensive characterization of the genetic mechanisms of caspase activation, we know little about whether and how cell geometry controls apoptosis commitment in developing tissues. Here, we combined multiscale time-lapse microscopy of developing Drosophila epithelium, quantitative characterization of cell behaviors, and genetic and mechanical perturbations to determine how apoptosis is controlled during epithelial tissue development. We found that early in cell lives and well before extrusion, apoptosis commitment is linked to two distinct geometric features: a small apical area compared with other cells within the tissue and a small relative apical area with respect to the immediate neighboring cells. We showed that these global and local geometric characteristics are sufficient to recapitulate the tissue-scale apoptotic pattern. Furthermore, we established that the coupling between these two geometric features and apoptotic cells is dependent on the Hippo/YAP and Notch pathways. Overall, by exploring the links between cell geometry and apoptosis commitment, our work provides important insights into the spatial regulation of cell death in tissues and improves our understanding of the mechanisms that control cell number and tissue size.
Topics: Animals; Epithelium; Drosophila; Apoptosis; Cell Death; Mitosis; Epithelial Cells
PubMed: 37827152
DOI: 10.1016/j.cub.2023.09.049 -
Scientific Reports Oct 2023Osteoimmune diseases, such as apical periodontitis, are prevalent, often painful, inflammatory conditions resulting in bone loss and reduced quality of life. There is...
Osteoimmune diseases, such as apical periodontitis, are prevalent, often painful, inflammatory conditions resulting in bone loss and reduced quality of life. There is growing evidence that the nociceptive fibers densely innervating affected tissues regulate disease progression; therefore, we hypothesized that nociceptors regulate the transcriptomic profile of the periapical osteolytic lesion in a mouse model of apical periodontitis. Male control and nociceptor-ablated mice underwent pulp exposures, and after 0, 7, or 14 days, total RNA from periapical tissues was submitted for sequencing and bioinformatic analysis. Pulp exposure triggers the differential expression of hundreds of genes over the course of infection. At 14 days post pulp exposure, 422 genes, including Tnf, Il1a, and Il1b, were differentially expressed between nociceptor-ablated and control mice with greater enrichment of biological processes related to inflammation in nociceptor-ablated mice. Nociceptor ablation regulates the transcriptomic profile of periapical lesions in a mouse model of apical periodontitis, shifting the gene expression profile to a greater enrichment of inflammatory genes, suggesting nociceptors play a role in the kinetics of the immune response. This newly uncovered neuro-immune axis and its mechanisms in apical periodontitis can be an important therapeutic target for the treatment of this prevalent disease.
Topics: Male; Mice; Animals; Transcriptome; Nociceptors; Quality of Life; Periapical Periodontitis; Periapical Tissue
PubMed: 37845223
DOI: 10.1038/s41598-023-44648-9 -
Current Research in Neurobiology 2024We argue that prediction success maximization is a basic objective of cognition and cortex, that it is compatible with but distinct from prediction error minimization,... (Review)
Review
We argue that prediction success maximization is a basic objective of cognition and cortex, that it is compatible with but distinct from prediction error minimization, that neither objective requires subtractive coding, that there is clear neurobiological evidence for the amplification of predicted signals, and that we are unconvinced by evidence proposed in support of subtractive coding. We outline recent discoveries showing that pyramidal cells on which our cognitive capabilities depend usually transmit information about input to their basal dendrites and amplify that transmission when input to their distal apical dendrites provides a context that agrees with the feedforward basal input in that both are depolarizing, i.e., both are excitatory rather than inhibitory. Though these intracellular discoveries require a level of technical expertise that is beyond the current abilities of most neuroscience labs, they are not controversial and acclaimed as groundbreaking. We note that this cellular cooperative context-sensitivity greatly enhances the cognitive capabilities of the mammalian neocortex, and that much remains to be discovered concerning its evolution, development, and pathology.
PubMed: 38665363
DOI: 10.1016/j.crneur.2024.100129 -
Cureus Jan 2024The close interrelationship between chronic oral and dental inflammatory diseases, such as periodontal and apical abscesses (AA), with the patient's systemic condition,... (Review)
Review
The close interrelationship between chronic oral and dental inflammatory diseases, such as periodontal and apical abscesses (AA), with the patient's systemic condition, is one of the most interesting topics of study common between dentists and the medical staff. Chronic apical periodontitis and periodontal diseases are chronic infections of the oral cavity in which similar Gram-negative anaerobic microbiota are found and in both infectious diseases increased local inflammatory mediators levels may influence overall systemic conditions. One of the most important systemic diseases linked to periodontal, as well as AA, is diabetes mellitus (DM); likewise, the prognosis of chronic apical periodontitis and endodontic treatment is also associated with how DM is controlled in the patient. periapical and periodontal diseases may also contribute to the quality of DM control. DM affects many systems in the body, the most important; cardiovascular and renal systems, and this necessitates obeying several keynotes to provide safe endodontic and periodontal disease control in these patients that is the aim of this article to clarify for clinicians.
PubMed: 38344477
DOI: 10.7759/cureus.52145 -
Proceedings of the National Academy of... Nov 2023In temperate and boreal regions, perennial plants adapt their annual growth cycle to the change of seasons. In natural forests, juvenile seedlings usually display longer...
In temperate and boreal regions, perennial plants adapt their annual growth cycle to the change of seasons. In natural forests, juvenile seedlings usually display longer growth seasons compared to adult trees to ensure their establishment and survival under canopy shade. However, how trees adjust their annual growth according to their age is not known. In this study, we show that age-dependent seasonal growth cessation is genetically controlled and found that the module, a key regulon of vegetative phase change (VPC), also triggers age-dependent growth cessation in trees. We show that promotes shoot elongation during vegetative growth, and its targets function in the same pathway but as repressors. We find that the regulon controls growth cessation in both leaves and shoot apices and through multiple pathways, but with a different mechanism compared to how the regulon controls VPC in annual plants. Taken together, our results reveal an age-dependent genetic network in mediating seasonal growth cessation, a key phenological process in the climate adaptation of perennial trees.
Topics: Seasons; Populus; Gene Regulatory Networks; Transcription Factors; Plant Leaves; Trees
PubMed: 37991940
DOI: 10.1073/pnas.2311226120 -
The American Journal of Cardiology Dec 2023Echocardiography-derived hemodynamic forces (HDF) allow calculation of intraventricular pressure gradients from routine transthoracic echocardiographic images. The...
Echocardiography-derived hemodynamic forces (HDF) allow calculation of intraventricular pressure gradients from routine transthoracic echocardiographic images. The evolution of HDF after cardiac resynchronization therapy (CRT) has not been investigated in large cohorts. The aim was to assess HDF in patients with heart failure implanted with CRT versus healthy controls. HDF were assessed before and 6 months after CRT. The following HDF parameters were calculated: (1) apical-basal strength, (2) lateral-septal strength, (3) the ratio of lateral-septal to apical-basal strength ratio, and (4) the force vector angle (1 and 2 representing the magnitude of HDF, 3 and 4 representing the orientation of HDF). In the propulsive phase of systole, the apical-basal impulse and the systolic force vector angle were measured. A total of 197 patients were included (age 64 ± 11 years, 62% male), with left ventricular ejection fraction ≤35%, QRS duration ≥130 ms and left bundle branch block. The magnitude of HDF was significantly lower and the orientation was significantly worse in patients with heart failure versus healthy controls. Immediately after CRT implantation, the apical-basal impulse and systolic force vector angle were significantly increased. Six months after CRT, improvement of apical-basal strength, lateral-septal to apical-basal strength ratio and the force vector angle occurred. When CRT was deactivated at 6 months, the increase in the magnitude of apical-basal HDF remained unchanged while the systolic force vector angle worsened significantly. In conclusion, HDF in CRT recipients reflect the acute effect of CRT and the effect of left ventricular reverse remodeling on intraventricular pressure gradients. Whether HDF analysis provides incremental value over established echocardiographic parameters, remains to be determined.
Topics: Humans; Male; Middle Aged; Aged; Female; Cardiac Resynchronization Therapy; Ventricular Function, Left; Stroke Volume; Treatment Outcome; Echocardiography; Heart Failure; Hemodynamics
PubMed: 37866395
DOI: 10.1016/j.amjcard.2023.09.098 -
Journal of Clinical and Experimental... Nov 2023The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment...
BACKGROUND
The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment failure. The limitations of currently available sealers necessitate the development of new materials to improve the success rate of endodontic treatment. Therefore, the objective of this study was to assess the apical microleakage of newly developed hydroxyapatite-based endodontic sealers, including one derived from eggshells, and compare them with other commercially available sealers.
MATERIAL AND METHODS
Eighty-five extracted human upper anterior teeth were selected for this study. The teeth were divided into 5 experimental groups and 2 control groups. The experimental groups were designated as follows: (1) HPSINT - obturated with gutta-percha cone and synthetic hydroxyapatite-based sealer, (2) BIOC - obturated with gutta-percha cone and Bio C-Sealer sealer, (3) AHPLUS-BC - obturated with gutta-percha cone and AHPLUS Bioceramic sealer, (4) AHP - obturated with gutta-percha cone and AHPLUS sealer, and (5) HPO - obturated with gutta-percha cone and sealer based on hydroxyapatite extracted from eggshells. Additionally, there were positive and negative control groups consisting of instrumented teeth filled with gutta-percha cones without any sealer and instrumented teeth without any filling, respectively. Methylene blue dye penetration was used to assess apical microleakage. Descriptive statistical analysis and Shapiro-Wilk normality test were applied to the observed results. As the samples followed a normal distribution, the ANOVA test was applied.
RESULTS
The control groups confirmed the validity of the experimental method, while the experimental groups showed varying degrees of dye penetration. The group obturated with Bio C-Sealer exhibited the highest mean apical microleakage, while AHPLUS Bioceramic sealer demonstrated lower mean than AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (<0.05). Finally, there was no difference between the synthetic hydroxyapatite-based sealer and AHPLUS Bioceramic sealer, AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (>0.05). No significant difference was observed between the hydroxyapatite-based sealers and the AHPLUS-BC sealer.
CONCLUSIONS
The results of this study suggest that the newly developed hydroxyapatite-based endodontic sealers, including the one derived from eggshells, may have a lower risk of apical microleakage compared to other commercially available sealers. These findings highlight the potential of hydroxyapatite-based sealers to improve the success rate of endodontic treatment. Further research and clinical studies are warranted to validate these results and explore the long-term effects of these novel sealers. Endodontic treatment, apical microleakage, endodontic sealer, hydroxyapatite, eggshell-derived sealer.
PubMed: 38074171
DOI: 10.4317/jced.60743 -
Computational and Structural... 2023Annexin A1 (ANXA1) is a multifunctional calcium-binding protein that can bind to membrane phospholipids. Under high-calcium condition, ANXA1 expression increases on...
Annexin A1 (ANXA1) is a multifunctional calcium-binding protein that can bind to membrane phospholipids. Under high-calcium condition, ANXA1 expression increases on renal epithelial cell surface, leading to enhanced adhesion of calcium oxalate (CaOx) crystal (stone material) onto the cells. To regulate various cellular processes, ANXA1 interacts with many other intracellular protein partners. However, components of the ANXA1-interacting protein complex remain unclear. Herein, we characterized the interacting complexes of apical membrane (ApANXA1) and cytosolic (cyANXA1) forms of ANXA1 in apical membrane and cytosolic compartments, respectively, of renal epithelial cells under high-calcium condition using proteomic and bioinformatic approaches. After fractionation, the ApANXA1- and CyANXA1-interacting partners were identified by immunoprecipitation followed by nanoLC‑ESI‑Qq-TOF tandem mass spectrometry (IP-MS/MS). The ANXA1-interacting partners that were common in both apical membrane and cytosolic compartments and those unique in each compartment were then analyzed for their physico-chemical properties (molecular weight, isoelectric point, amino acid contents, instability index, aliphatic index, and grand average of hydropathicity), secondary structure (α-helix, β-turn, random coil, and extended strand), molecular functions, biological processes, reactome pathways and KEGG pathways. The data demonstrated that each set of these interacting proteins exhibited common and unique characteristics and properties. The knowledge from this study may lead to better understanding of the ApANXA1 and CyAXNA1 biochemistry and functions as well as the pathophysiology of CaOx kidney stone formation induced by high-calcium condition.
PubMed: 37560129
DOI: 10.1016/j.csbj.2023.07.037