Read by QxMD icon Read

Oriented Cell Division

Simone Culurgioni, Sara Mari, Paola Bonetti, Sara Gallini, Greta Bonetto, Martha Brennich, Adam Round, Francesco Nicassio, Marina Mapelli
Asymmetric cell divisions balance stem cell proliferation and differentiation to sustain tissue morphogenesis and homeostasis. During asymmetric divisions, fate determinants and niche contacts segregate unequally between daughters, but little is known on how this is achieved mechanistically. In Drosophila neuroblasts and murine mammary stem cells, the association of the spindle orientation protein LGN with the stem cell adaptor Inscuteable has been connected to asymmetry. Here we report the crystal structure of Drosophila LGN in complex with the asymmetric domain of Inscuteable, which reveals a tetrameric arrangement of intertwined molecules...
March 9, 2018: Nature Communications
Mohammed Benadallah, Oualid Talhi, Fatiha Nouali, Nourredine Choukchou-Braham, Khaldoun Bachari, Artur M S Silva
The present review deals with the progress in medicinal chemistry of spirocyclic compounds, a wider class of natural and synthetic organic molecules, defined as a hybrid of two molecular entities covalently linked via a unique tetrahedral carbon. This spiro central carbon confers to the molecules a tridimensional structurally oriented framework, which is found in many medicinally relevant compounds, a well-known example is the anti-hypertensive spironolactone. Various bioactive natural products possess the privileged spiro linkage and different chemo-types thereof become synthetically accessible since the 20th century...
March 9, 2018: Current Medicinal Chemistry
Nader R Abdelsalam, Ahmed Abdel-Megeed, Hayssam M Ali, Mohamed Z M Salem, Muwafaq F A Al-Hayali, Mohamed S Elshikh
The distribution and use of nanoparticles have rapidly increased over recent years, but the available knowledge regarding their mode of action, ecological tolerance and biodegradability remains insufficient. Wheat (Triticum aestivum L.) is the most important crop worldwide. In the current study, the effects of silver nanoparticles (AgNPs) obtained from two different sources, namely, green and chemical syntheses, on chromosomal aberrations and cell division were investigated. Wheat root tips were treated with four different AgNP concentrations (10, 20, 40 and 50 ppm) for three different exposure durations (8, 16 and 24 h), and the different concentrations of the nanoparticles were added to the tested grains until the root lengths reached 1...
March 3, 2018: Ecotoxicology and Environmental Safety
Delphine Duteil, Yves Tourette, Adrien Eberlin, Dominica Willmann, Dharmeshkumar Patel, Nikolaus Friedrichs, Judith M Müller, Roland Schüle
Nir/ Noc2l is an inhibitor of histone acetyl-transferases (INHAT). In addition to its function on histone acetylation, Nir binds to p53 and TAp63 to regulate their activity. Here, we show that epidermis-specific ablation of Nir impairs epidermal stratification and barrier function, thereby causing perinatal lethality. Nir-deficient epidermis lacks appendages and remains single layered during embryogenesis. Cell proliferation is inhibited, whereas apoptosis and p53 acetylation is increased, indicating that Nir is controlling cell proliferation by limiting p53 acetylation...
February 28, 2018: Development
Thurston Lacalli
The axonal projection from the retina to the optic tectum maps visual information isomorphically from one to the other and serves as a model for the development of sensory maps more generally in the vertebrate brain. How or why this connection evolved is not known, nor why the midbrain is so important to the processing of visual information. Amphioxus is potentially informative here because its eye homolog, the frontal eye, also has a neural connection to a region of the brain now known to be homologous with the caudal diencephalon and midbrain...
2018: EvoDevo
Deepak Saini, Yojiro Yamanaka
During the first few days in the mouse preimplantation embryo, two types of cells, polar and apolar cells are generated from spherical totipotent blastomeres. Sequential morphogenetic events, polarization, compaction, and asymmetric division, are essential for the generation of the first distinct cell populations, polar and apolar cells, which establish the outer/inner configuration within the embryo. This leads to position-dependent activation of the Hippo signaling pathway and lineage-specific gene expression to form the trophectoderm and inner cell mass in a blastocyst...
2018: Current Topics in Developmental Biology
Annika K Weimer, Juliana L Matos, Nidhi Sharma, Farah Patell, James A H Murray, Walter Dewitte, Dominique C Bergmann
Plants, with cells fixed in place by rigid walls, often utilize spatial and temporally distinct cell division programs to organize and maintain organs. This leads to the question of how developmental regulators interact with the cell cycle machinery to link cell division events with particular developmental trajectories. In Arabidopsis leaves, the development of stomata, 2-celled epidermal valves that mediate plant-atmosphere gas exchange, relies on a series of oriented stem-cell-like asymmetric divisions followed by a single symmetric division...
February 21, 2018: Development
Jingchen Li, Hongyuan Jiang
Proper location of the mitotic spindle is critical for chromosome segregation and the selection of the cell division plane. However, how mitotic spindles sense cell size and shape to regulate their own position and orientation is still largely unclear. To investigate this question systematically, we used a general model by considering chromosomes, microtubule dynamics, and forces of various molecular motors. Our results show that in cells of various sizes and shapes, spindles can always be centered and oriented along the long axis robustly in the absence of other specified mechanisms...
January 2018: Physical Review. E
Florian Razy-Krajka, Basile Gravez, Nicole Kaplan, Claudia Racioppi, Wei Wang, Lionel Christiaen
In embryos, multipotent progenitors divide to produce distinct progeny and express their full potential. In vertebrates, multipotent cardiopharyngeal progenitors produce second-heart-field-derived cardiomyocytes, and branchiomeric skeletal head muscles. However, the mechanisms underlying these early fate choices remain largely elusive. The tunicate Ciona emerged as an attractive model to study early cardiopharyngeal development at high resolution: through two asymmetric and oriented divisions, defined cardiopharyngeal progenitors produce distinct first and second heart precursors, and pharyngeal muscle (aka atrial siphon muscle, ASM) precursors...
February 6, 2018: ELife
Mai Mochizuki, Taka Nakahara
BACKGROUND: Currently, ex-vivo handling of stem cells, including transport after harvest and therapeutic preparation, is generally done in culture media containing fetal bovine serum (FBS), which promotes cell attachment, proliferation, and differentiation. However, because of safety concerns associated with the use of FBS, including potential transmission of zoonotic agents and transplant rejection because of the incorporation of foreign proteins into the stem cells, there is a need for xenogeneic serum-free culture media for clinical handling of stem cells...
February 3, 2018: Stem Cell Research & Therapy
Bandan Chakrabortty, Ikram Blilou, Ben Scheres, Bela M Mulder
Plant morphogenesis is strongly dependent on the directional growth and the subsequent oriented division of individual cells. It has been shown that the plant cortical microtubule array plays a key role in controlling both these processes. This ordered structure emerges as the collective result of stochastic interactions between large numbers of dynamic microtubules. To elucidate this complex self-organization process a number of analytical and computational approaches to study the dynamics of cortical microtubules have been proposed...
February 2, 2018: PLoS Computational Biology
Che-Yang Liao, Dolf Weijers
Considerable progress had been made to understand the influence of physical and genetic factors on the patterns of cell division in various model systems. However, how each of these factors direct changes in subcellular structures has remained unclear. Generic machineries for the execution of cell expansion and division have been characterized, but how these are influenced by genetic regulators and physical cell properties remains an open question. To a large degree, the complexity of growing post-embryonic tissues, and the lack of precise predictability have prevented the extraction of rigid correlations between subcellular structures and future cell division orientation...
January 31, 2018: Plant Journal: for Cell and Molecular Biology
Jennifer K Heppert, Ariel M Pani, Allyson M Roberts, Daniel J Dickinson, Bob Goldstein
Oriented cell divisions are critical to establish and maintain cell fates and tissue organization. Diverse extracellular and intracellular cues have been shown to provide spatial information for mitotic spindle positioning, however, the molecular mechanisms by which extracellular signals communicate with cells to direct mitotic spindle positioning are largely unknown. In animal cells, oriented cell divisions are often achieved by the localization of force-generating, motor protein complexes to discrete cortical domains...
January 18, 2018: Genetics
Zan Tang, Yucheng Hu, Zheng Wang, Kewu Jiang, Cheng Zhan, Wallace F Marshall, Nan Tang
Oriented cell division plays a key role in controlling organogenesis. The mechanisms for regulating division orientation at the whole-organ level are only starting to become understood. By combining 3D time-lapse imaging, mouse genetics, and mathematical modeling, we find that global orientation of cell division is the result of a combination of two types of spindles with distinct spindle dynamic behaviors in the developing airway epithelium. Fixed spindles follow the classic long-axis rule and establish their division orientation before metaphase...
January 9, 2018: Developmental Cell
Xia He, Suya Du, Tiantian Lei, Xiang Li, Yilong Liu, Hailian Wang, Rongsheng Tong, Yi Wang
Tumor cell metabolism is characterized by abundant glucose consumption and aerobic glycolysis. And pyruvate kinase M2 (PKM2) plays a decisive role in glycolysis, significantly contributing to the Warburg effect, tumor growth, angiogenesis, cell division, metastasis and apoptosis. To date, researchers have unraveled the potential of pyruvate kinase M2 as an antitumor target, which suggests a new orientation for oncotherapy. Herein, we focus on the role of pyruvate kinase M2 in tumor cell development and its function as a potential new therapeutic target for tumor treatment...
December 15, 2017: Oncotarget
Matloob Khushi, Imraan M Dean, Erdahl T Teber, Megan Chircop, Jonathan W Arthur, Neftali Flores-Rodriguez
BACKGROUND: Cell division (mitosis) results in the equal segregation of chromosomes between two daughter cells. The mitotic spindle plays a pivotal role in chromosome alignment and segregation during metaphase and anaphase. Structural or functional errors of this spindle can cause aneuploidy, a hallmark of many cancers. To investigate if a given protein associates with the mitotic spindle and regulates its assembly, stability, or function, fluorescence microscopy can be performed to determine if disruption of that protein induces phenotypes indicative of spindle dysfunction...
December 28, 2017: BMC Bioinformatics
Antoine Vallot, Ioanna Leontiou, Damien Cladière, Warif El Yakoubi, Susanne Bolte, Eulalie Buffin, Katja Wassmann
Cell division with partitioning of the genetic material should take place only when paired chromosomes named bivalents (meiosis I) or sister chromatids (mitosis and meiosis II) are correctly attached to the bipolar spindle in a tension-generating manner. For this to happen, the spindle assembly checkpoint (SAC) checks whether unattached kinetochores are present, in which case anaphase onset is delayed to permit further establishment of attachments. Additionally, microtubules are stabilized when they are attached and under tension...
December 16, 2017: Current Biology: CB
Xin Xiang
Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division...
December 11, 2017: Seminars in Cell & Developmental Biology
Krzysztof Kucypera, Marcin Lipowczan, Anna Piekarska-Stachowiak, Jerzy Nakielski
Background: The development of cell pattern in the surface cell layer of the shoot apex can be investigated in vivo by use of a time-lapse confocal images, showing naked meristem in 3D in successive times. However, how this layer is originated from apical initials and develops as a result of growth and divisions of their descendants, remains unknown. This is an open area for computer modelling. A method to generate the surface cell layer is presented on the example of the 3D paraboloidal shoot apical dome...
2017: Plant Methods
Kaori Sugimura, Hiroshi Kori
Ordered polarity alignment of cell populations plays vital roles in biology, such as in hair follicle alignment and asymmetric cell division. Although cell polarity is uniformly oriented along a tissue axis in many tissues, its mechanism is not well understood. In this paper, we propose a theoretical framework to understand the generic dynamical properties of polarity alignment in interacting cellular units, where each cell is described by a reaction-diffusion system, and the cells further interact with one another through the contacting surfaces between them...
December 12, 2017: Scientific Reports
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"