Pancreas Cell Physiology and Pancreatitis Cell Biology

Pancreatology ◽  
2003 ◽  
Vol 3 (3) ◽  
pp. 207-208 ◽  
Author(s):  
Fred S. Gorelick
Keyword(s):  
Cell Biology ◽  
Cell Physiology ◽  
Pancreas Cell

scholarly journals A cellular endolysosome-modulating pore-forming protein from a toad is negatively regulated by its paralog under oxidizing conditions

2020 ◽  
Vol 295 (30) ◽  
pp. 10293-10306 ◽  
Author(s):  
Qiquan Wang ◽  
Xianling Bian ◽  
Lin Zeng ◽  
Fei Pan ◽  
Lingzhen Liu ◽  
...  
Keyword(s):  
Disulfide Bond ◽  
Cell Biology ◽  
Biochemical Properties ◽  
Bacterial Toxin ◽  
Cell Physiology ◽  
Dependent Manner ◽  
Membrane Pore ◽  
Intracellular Vesicles

Endolysosomes are key players in cell physiology, including molecular exchange, immunity, and environmental adaptation. They are the molecular targets of some pore-forming aerolysin-like proteins (ALPs) that are widely distributed in animals and plants and are functionally related to bacterial toxin aerolysins. βγ-CAT is a complex of an ALP (BmALP1) and a trefoil factor (BmTFF3) in the firebelly toad (Bombina maxima). It is the first example of a secreted endogenous pore-forming protein that modulates the biochemical properties of endolysosomes by inducing pore formation in these intracellular vesicles. Here, using a large array of biochemical and cell biology methods, we report the identification of BmALP3, a paralog of BmALP1 that lacks membrane pore-forming capacity. We noted that both BmALP3 and BmALP1 contain a conserved cysteine in their C-terminal regions. BmALP3 was readily oxidized to a disulfide bond-linked homodimer, and this homodimer then oxidized BmALP1 via disulfide bond exchange, resulting in the dissociation of βγ-CAT subunits and the elimination of biological activity. Consistent with its behavior in vitro, BmALP3 sensed environmental oxygen tension in vivo, leading to modulation of βγ-CAT activity. Interestingly, we found that this C-terminal cysteine site is well conserved in numerous vertebrate ALPs. These findings uncover the existence of a regulatory ALP (BmALP3) that modulates the activity of an active ALP (BmALP1) in a redox-dependent manner, a property that differs from those of bacterial toxin aerolysins.

scholarly journals Biological cell-based screening for scientific membranal and cytoplasmatic markers using dielectric spectroscopy

2008 ◽  
Vol 2 (2) ◽  
pp. 111-121
Author(s):  
Ragini Raj Singh ◽  
◽  
Amit Ron ◽  
Nick Fishelson ◽  
Irena Shur ◽  
...  
Keyword(s):  
Cell Lines ◽  
Dielectric Spectroscopy ◽  
Cell Biology ◽  
Screening Tool ◽  
Excitation Frequency ◽  
Cell Physiology ◽  
Biological Cell ◽  
Non Invasive ◽  
Native Cell ◽  
Biology Research

Dielectric spectroscopy (DS) of living biological cells is based on the analysis of cells suspended in a physiological medium. It provides knowledge of the polarization-relaxation response of the cells to external electric field as function of the excitation frequency. This response is strongly affected by both structural and molecular properties of the cells and, therefore, can reveal rare insights into cell physiology and behaviour. This study demonstrates the mapping potential of DS after cytoplasmic and membranal markers for cell-based screening analysis. The effect of membrane permittivity and cytoplasm conductivity was examined using tagged MBA and MDCK cell lines respectively. The comparison of the dielectric spectra of tagged and native cell lines reveals clear differences between the cells. In addition, the differences in the matching dielectric properties of the cells were discovered. Those findings support the high distinction resolution and sensitivity of DS after fine molecular and cellular changes, and hence, highlight the high potential of DS as non invasive screening tool in cell biology research.

scholarly journals J. Murdoch Mitchison. 11 June 1922—17 March 2011

2019 ◽  
Vol 67 ◽  
pp. 279-306
Author(s):  
Peter Fantes ◽  
Sally Mitchison
Keyword(s):  
Cell Biology ◽  
Sea Urchins ◽  
Growth Cycle ◽  
Cell Physiology ◽  
Time Work ◽  
University Of Edinburgh ◽  
Membrane Changes ◽  
Post War ◽  
The University ◽  
Zoology Department

John Murdoch Mitchison, known as Murdoch, was elected FRS in recognition of his work on the cell cycle. This emerged from a lifelong interest in the natural sciences, interrupted by war-time work in Operational Research which developed his critical appraisal of research technique. Post-war, he completed a PhD at Cambridge, then worked with Sir Michael Swann FRS (1962) on mitotic membrane changes in sea urchins. In 1953 Murdoch joined the University of Edinburgh Zoology Department and in time switched his interest to the fission yeast Schizosaccharomyces pombe . Over the next 30 years he investigated cell growth and division, employing a meticulous approach to experiments. He considered there to be a ‘growth cycle’ in cells, independent of the DNA-division cycle. There is experimental evidence to support this idea, but further investigations of it have been limited. Actively fostering a relaxed but industrious and enquiring ethos in the lab, Murdoch ran the department jointly with Aubrey Manning. The Mitchison group's work at Edinburgh attracted students including Paul Nurse (later Sir Paul Nurse; FRS 1989, PRS 2010–2015), Béla Novak, Kim Nasmyth (FRS 1989) and Peter Fantes as well as many visiting academics. Murdoch's work on S. pombe came to both national and international recognition, forming a foundation for the current thriving community of researchers in cell physiology, cell genetics and molecular biology. Murdoch is remembered for his single-minded commitment to cell biology research and his generous, fair-minded support of younger colleagues and students. He was, additionally, an expert landscape gardener, a convivial host and phenomenally well-informed on most subjects.

SEARCHING AND MINING VISUALLY OBSERVED PHENOTYPES OF MAIZE MUTANTS

2007 ◽  
Vol 05 (06) ◽  
pp. 1193-1213 ◽  
Author(s):  
CHI-REN SHYU ◽  
JATURON HARNSOMBURANA ◽  
JASON GREEN ◽  
ADRIAN S. BARB ◽  
TONI KAZIC ◽  
...  
Keyword(s):  
Cell Biology ◽  
Species Conservation ◽  
Genetic Maps ◽  
Cell Physiology ◽  
Complex Processes ◽  
Intimate Knowledge ◽  
Scientific Challenge ◽  
Underlying Mechanisms ◽  
Mutant Phenotypes ◽  
High Level

There are thousands of maize mutants, which are invaluable resources for plant research. Geneticists use them to study underlying mechanisms of biochemistry, cell biology, cell development, and cell physiology. To streamline the understanding of such complex processes, researchers need the most current versions of genetic and physical maps, tools with the ability to recognize novel phenotypes or classify known phenotypes, and an intimate knowledge of the biochemical processes generating physiological and phenotypic effects. They must also know how all of these factors change and differ among species, diverse alleles, germplasms, and environmental conditions. While there are robust databases, such as MaizeGDB, for some of these types of raw data, other crucial components are missing. Moreover, the management of visually observed mutant phenotypes is still in its infant stage, let alone the complex query methods that can draw upon high-level and aggregated information to answer the questions of geneticists. In this paper, we address the scientific challenge and propose to develop a robust framework for managing the knowledge of visually observed phenotypes, mining the correlation of visual characteristics with genetic maps, and discovering the knowledge relating to cross-species conservation of visual and genetic patterns. The ultimate goal of this research is to allow a geneticist to submit phenotypic and genomic information on a mutant to a knowledge base and ask, "What genes or environmental factors cause this visually observed phenotype?".

Cellular microbiology: can we learn cell physiology from microorganisms?

1999 ◽  
Vol 276 (4) ◽  
pp. C765-C776 ◽  
Author(s):  
Alessio Fasano
Keyword(s):  
Cell Biology ◽  
Molecular Basis ◽  
Bacterial Pathogenesis ◽  
Molecular Techniques ◽  
Microbial Pathogens ◽  
Cell Physiology ◽  
Diarrheal Diseases ◽  
Host Interaction ◽  
The Way

Cellular microbiology is a new discipline that is emerging at the interface between cell biology and microbiology. The application of molecular techniques to the study of bacterial pathogenesis has made possible discoveries that are changing the way scientists view the bacterium-host interaction. Today, research on the molecular basis of the pathogenesis of infective diarrheal diseases of necessity transcends established boundaries between cell biology, bacteriology, intestinal pathophysiology, and immunology. The use of microbial pathogens to address questions in cell physiology is just now yielding promising applications and striking results.

scholarly journals Increased expression of Polδ does not alter the canonical replication program in vivo

2021 ◽  
Vol 6 ◽  
pp. 44
Author(s):  
Róbert Zach ◽  
Antony M. Carr
Keyword(s):  
Cell Biology ◽  
Rare Event ◽  
Replication Initiation ◽  
Cell Physiology ◽  
Moderate Increase ◽  
Sequencing Analysis ◽  
Phase Duration ◽  
Leading Strand ◽  
The Impact

Background: In vitro experiments utilising the reconstituted Saccharomyces cerevisiae eukaryotic replisome indicated that the efficiency of the leading strand replication is impaired by a moderate increase in Polδ concentration. It was hypothesised that the slower rate of the leading strand synthesis characteristic for reactions containing two-fold and four-fold increased concentration of Polδ represented a consequence of a relatively rare event, during which Polδ stochastically outcompeted Polε and, in an inefficient manner, temporarily facilitated extension of the leading strand. Inspired by this observation, we aimed to determine whether similarly increased Polδ levels influence replication dynamics in vivo using the fission yeast Schizosaccharomyces pombe as a model system. Methods: To generate S. pombe strains over-expressing Polδ, we utilised Cre-Lox mediated cassette exchange and integrated one or three extra genomic copies of all four Polδ genes. To estimate expression of respective Polδ genes in Polδ-overexpressing mutants, we measured relative transcript levels of cdc1+, cdc6+ (or cdc6L591G), cdc27+ and cdm1+ by reverse transcription followed by quantitative PCR (RT-qPCR). To assess the impact of Polδ over-expression on cell physiology and replication dynamics, we used standard cell biology techniques and polymerase usage sequencing. Results: We provide an evidence that two-fold and four-fold over-production of Polδ does not significantly alter growth rate, cellular morphology and S-phase duration. Polymerase usage sequencing analysis further indicates that increased Polδ expression does not change activities of Polδ, Polε and Polα at replication initiation sites and across replication termination zones. Additionally, we show that mutants over-expressing Polδ preserve WT-like distribution of replication origin efficiencies. Conclusions: Our experiments do not disprove the existence of opportunistic polymerase switches; however, the data indicate that, if stochastic replacement of Polε for Polδ does occur in vivo, it represents a rare phenomenon that does not significantly influence canonical replication program.

scholarly journals Multiplex shRNA Screening of Germ Cell Development by in vivo Transfection of Mouse Testis

2016 ◽  
Author(s):  
Nicholas R. Y. Ho ◽  
Abul R. Usmani ◽  
Yan Yin ◽  
Liang Ma ◽  
Donald F. Conrad
Keyword(s):  
Germ Cell ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Gene Knockout ◽  
Mouse Testis ◽  
Separate Experiment ◽  
Great Promise ◽  
Cell Physiology ◽  
Functional Screening

AbstractSpermatozoa are one of the few mammalian cells types that cannot be fully derived in vitro, severely limiting the application of modern genomic techniques to study germ cell biology. The current gold standard approach of characterizing single gene knockout mice is slow as generation of each mutant line can take 6-9 months. Here, we describe an in vivo approach to rapid functional screening of germline genes based on a new non-surgical, non-viral in vivo transfection method to deliver nucleic acids into testicular germ cells. By coupling multiplex transfection of short hairpin RNA constructs with pooled amplicon sequencing as a readout, we were able to screen many genes for spermatogenesis function in a quick and inexpensive experiment. We transfected nine mouse testes with a pilot pool of RNAi against well-characterized genes to show that this system is highly reproducible and accurate. With a false negative rate of 18% and a false positive rate of 12%, this method has similar performance as other RNAi screens in the well-described Drosophila model system. In a separate experiment, we screened 26 uncharacterized genes computationally predicted to be essential for spermatogenesis and found numerous candidates for follow up studies. Further, by characterizing the effect of both libraries on neuronal N2a cells, we show that our screening results from testis are tissue-specific. Our calculations indicate that the current implementation of this approach could be used to screen thousands of protein-coding genes simultaneously in a single mouse testis. The experimental protocols and analysis scripts provided will enable other groups to use this procedure to study diverse aspects of germ cell biology ranging from epigenetics to cell physiology. This approach also has great promise as an applied tool for validating diagnoses made from medical genome sequencing, or designing synthetic biological sequences that act as potent and highly specific male contraceptives.

scholarly journals New food components and gastrointestinal health

2001 ◽  
Vol 60 (4) ◽  
pp. 481-488 ◽  
Author(s):  
Ian T. Johnson
Keyword(s):  
Cell Biology ◽  
Chemical Species ◽  
Muscular Activity ◽  
Biologically Active ◽  
Autonomous Nervous System ◽  
Cell Physiology ◽  
Processing Technologies ◽  
Food Ingredients ◽  
Gastrointestinal Health ◽  
Commensal Flora

Apart from its main functions of digestion, absorption and faecal processing, the human gastrointestinal tract has a complex pattern of muscular activity regulated by a largely autonomous nervous system, and its various organs contain large concentrations of immune and endocrine tissues. Any failure of these closely-integrated systems can lead to diseases ranging from the mildly irritating to the life threatening. Food contains a huge variety of chemical species, many of which are biologically active, and the distal regions of the gut are colonised by a rich and metabolically-active commensal flora that depend on nutrients derived ultimately from the host’s dietary residues. The present paper explores the evidence for significant effects of food ingredients on functional bowel disorders, intestinal infections, and aspects of epithelial cell physiology involved in the development of colo-rectal neoplasia. Various strategies, including the manipulation of the colo-rectal microflora with pre- and probiotics, and the development of new products and plant varieties containing biologically-active constituents, have the potential to underpin the development of novel functional food products. However, these products will need to be based on proven biological principles, and fully tested for efficacy and safety. The rapidly-developing fields of functional genomics and cell biology will open up new experimental strategies to explore these possibilities, and emerging processing technologies seem likely to provide novel methods for their exploitation.

scholarly journals Ribonuclease J-Mediated mRNA Turnover Modulates Cell Shape, Metabolism and Virulence in Corynebacterium diphtheriae

2021 ◽  
Vol 9 (2) ◽  
pp. 389
Author(s):  
Truc Thanh Luong ◽  
Minh Tan Nguyen ◽  
Yi-Wei Chen ◽  
Chungyu Chang ◽  
Ju Huck Lee ◽  
...  
Keyword(s):  
Cell Biology ◽  
Cell Shape ◽  
Type Strain ◽  
Wild Type Strain ◽  
Corynebacterium Diphtheriae ◽  
Rna Degradation ◽  
Mrna Turnover ◽  
Cell Physiology ◽  
Wild Type ◽  
Cell Width

Controlled RNA degradation is a crucial process in bacterial cell biology for maintaining proper transcriptome homeostasis and adaptation to changing environments. mRNA turnover in many Gram-positive bacteria involves a specialized ribonuclease called RNase J (RnJ). To date, however, nothing is known about this process in the diphtheria-causative pathogen Corynebacterium diphtheriae, nor is known the identity of this ribonuclease in this organism. Here, we report that C. diphtheriae DIP1463 encodes a predicted RnJ homolog, comprised of a conserved N-terminal β-lactamase domain, followed by β-CASP and C-terminal domains. A recombinant protein encompassing the β-lactamase domain alone displays 5′-exoribonuclease activity, which is abolished by alanine-substitution of the conserved catalytic residues His186 and His188. Intriguingly, deletion of DIP1463/rnj in C. diphtheriae reduces bacterial growth and generates cell shape abnormality with markedly augmented cell width. Comparative RNA-seq analysis revealed that RnJ controls a large regulon encoding many factors predicted to be involved in biosynthesis, regulation, transport, and iron acquisition. One upregulated gene in the ∆rnj mutant is ftsH, coding for a membrane protease (FtsH) involved in cell division, whose overexpression in the wild-type strain also caused cell-width augmentation. Critically, the ∆rnj mutant is severely attenuated in virulence in a Caenorhabditis elegans model of infection, while the FtsH-overexpressing and toxin-less strains exhibit full virulence as the wild-type strain. Evidently, RNase J is a key ribonuclease in C. diphtheriae that post-transcriptionally influences the expression of numerous factors vital to corynebacterial cell physiology and virulence. Our findings have significant implications for basic biological processes and mechanisms of corynebacterial pathogenesis.

scholarly journals The Literature Review of Electricity Effects on Cell Physiology and Related New Electrical Treatment Modalities

2019 ◽  
Author(s):  
Ertunc Simdi ◽  
Kader Ozcan
Keyword(s):  
Literature Review ◽  
Electric Fields ◽  
Cell Biology ◽  
Experimental Studies ◽  
Low Frequency ◽  
Pulsed Electric Fields ◽  
Treatment Modalities ◽  
Cell Physiology ◽  
Extremely Low Frequency ◽  
New Treatment

This paper is a mini literature review about electromagnetic field’s effects on cells, tissues and new treatment modalities. We have reviewed a papers which have been published in high quality journals in the last 5 years as two authors. This review’s aim is to be a resource for experimental studies about electricity’s effects on cell biology and pathophysiology. As a result of this literature review, we found that especially extremely low electric frequency and intermediate frequency fields have very important pathophysiological effects. We have mentioned four important expressions on this subject; electroporation, electrofusion, electrochemotherapy, gene electrotransference. Two different new treatment approaches have been developed by use of these two important electrical waves. First is tumor treating fields and the other is pulsed electric fields. Most studies in literature have been done with extremely low frequency and pulsed electric fields. In terms of diseases, most studies are about glioblastoma multiforme and malign melanoma.Most studies in literature have been done with extremely low frequency and pulsed electric fields. In terms of diseases, most studies are about glioblastoma and melanoma.

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