The role of the dehydration stage in the post-hypertonic hemolysis of mammalian erythrocytes

The aim of this study was to assess the level of damage to mammalian erythrocytes under post-hypertonic shock depending on the concentration of NaCl in the dehydration medium and to determine the effect of hypertonic NaCl solutions on the condition of mammalian erythrocytes by flow cytometry. To achieve this goal, spectrophotometric and cytometry research methods were used. The data obtained showed that post-hypertonic lysis of mammalian erythrocytes depends on the concentration of NaCl in the dehydration medium. The most sensitive to the effects of post-hypertonic shock are rat erythrocytes, the least sensitive are rabbit cells. Cytometry studies revealed significant changes in the histograms of the distribution of erythrocytes of all mammalian species with increasing salt concentration in the dehydration medium. These changes are species-specific and are probably related to changes in cell volume and morphology. The data revealed a relationship between the level of post-hypertonic hemolysis and the values of such indicators as the median distribution and the coefficient of variation. Thus, an increase in the sensitivity of mammalian erythrocytes to post-hypertonic shock with increasing salt concentration in dehydration medium was usually accompanied by a decrease in the median cell division, and higher values of the coefficient of variation are characteristic of mammalian erythrocytes resistant to post-hypertonic shock.

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Adult hippocampal neurogenesis of mammals: evolution and life history

Biology Letters ◽

10.1098/rsbl.2008.0511 ◽

2008 ◽

Vol 5 (1) ◽

pp. 141-144 ◽

Cited By ~ 50

Author(s):

Irmgard Amrein ◽

Hans-Peter Lipp

Keyword(s):

Hippocampal Formation ◽

Mammalian Species ◽

Critical Role ◽

Hippocampal Neurogenesis ◽

Adult Hippocampal Neurogenesis ◽

Mammalian Brain ◽

Spatial Learning And Memory ◽

Species Specific ◽

Species Being

Substantial production of new neurons in the adult mammalian brain is restricted to the olfactory system and the hippocampal formation. Its physiological and behavioural role is still debated. By comparing adult hippocampal neurogenesis (AHN) across many mammalian species, one might recognize a common function. AHN is most prominent in rodents, but shows considerable variability across species, being lowest or missing in primates and bats. The latter finding argues against a critical role of AHN in spatial learning and memory. The common functional denominator across all species investigated thus far is a strong decline of AHN from infancy to midlife. As predicted by Altman and colleagues in 1973, this implies a role in transforming juvenile unpredictable to predictable behaviour, typically characterizing mammalian behaviour once reproductive competence has been attained. However, as only a fraction of mammalian species has been investigated, further comparative studies are necessary in order to recognize whether AHN has a common unique function, or whether it mediates species-specific hippocampal functions.

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The function of slime from Physarum flavicomum in the control of cell division

Canadian Journal of Microbiology ◽

10.1139/m75-270 ◽

1975 ◽

Vol 21 (11) ◽

pp. 1866-1876 ◽

Cited By ~ 8

Author(s):

Henry R. Henney Jr. ◽

Mortaza Asgari

Keyword(s):

Cell Division ◽

Large Population ◽

Inhibitory Effect ◽

Haploid Cell ◽

Subsequent Growth ◽

Bacterium Bacillus Subtilis ◽

Bacterium Bacillus ◽

Species Specific ◽

Rna And Dna

A haploid cell of the myxomycete Physarum flavicomum undergoes cytokinesis, producing a large population of cells. However, after syngamy, cytokinesis no longer occurs but karyokinesis does and subsequent growth results in the formation of a diploid syncytial Plasmodium. Slime, which is produced by the Plasmodium but not the haploid cells, was aseptically isolated and purified, and tested for its effect as a cytokinetic regulator. Slime (a viscous, high molecular weight, acidic glycoprotein) affected cytokinesis of the haploid myxamoebae growing in pure culture in soluble media, and the effect was concentration dependent. In simple media, a slime concentration of about 6 × 10−5 μg protein per cell suppressed cytokinesis about 50%, unequally inhibited the synthesis of protein, RNA, and DNA, but stimulated respiration. The biological activity of slime was not species specific and it also affected the bacterium Bacillus subtilis by inhibiting cytokinesis, stimulating oxygen uptake, and producing an aberrant cell morphology. Slime was inactivated by heat, fragmentation, and incubation with dithiothreitol, mercaptoethanol, and the proteolytic enzyme papain (EC 3.4.22.2). The inhibitory effect of slime on cell division of haploid cells could not be achieved using mucin or various polyanions. The possible role of slime in the production of the diploid syncytium is discussed.

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Lipid droplets in mammalian eggs are utilized during embryonic diapause

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2018362118 ◽

2021 ◽

Vol 118 (10) ◽

pp. e2018362118

Author(s):

Roberta Arena ◽

Simona Bisogno ◽

Łukasz Gąsior ◽

Joanna Rudnicka ◽

Laura Bernhardt ◽

...

Keyword(s):

Lipid Droplets ◽

Mammalian Species ◽

Diagnostic Techniques ◽

Blastocyst Stage ◽

Embryonic Diapause ◽

Uterine Receptivity ◽

Preimplantation Embryo Development ◽

Mechanical Removal ◽

Species Specific

Embryonic diapause (ED) is a temporary arrest of an embryo at the blastocyst stage when it waits for the uterine receptivity signal to implant. ED used by over 100 species may also occur in normally “nondiapausing” mammals when the uterine receptivity signal is blocked or delayed. A large number of lipid droplets (LDs) are stored throughout the preimplantation embryo development, but the amount of lipids varies greatly across different mammalian species. Yet, the role of LDs in the mammalian egg and embryo remains unknown. Here, using a mouse model, we provide evidence that LDs play a crucial role in maintaining ED. By mechanical removal of LDs from zygotes, we demonstrated that delipidated embryos are unable to survive during ED. LDs are not essential for normal prompt implantation, without ED. We further demonstrated that with the progression of ED, the amount of intracellular lipid reduces, and composition changes. This decrease in lipid is caused by a switch from carbohydrate metabolism to lipid catabolism in diapausing blastocysts, which also exhibit increased release of exosomes reflecting elevated embryonic signaling to the mother. We have also shown that presence of LDs in the oocytes of various mammals positively corelates with their species-specific length of diapause. Our results reveal the functional role of LDs in embryonic development. These results can help to develop diagnostic techniques and treatment of recurrent implantation failure and will likely ignite further studies in developmental biology and reproductive medicine fields.

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Loss of the cleaved-protamine 2 domain leads to incomplete histone-to-protamine exchange and infertility in mice

10.1101/2021.09.29.462440 ◽

2021 ◽

Author(s):

Lena Arévalo ◽

Gina Esther Merges ◽

Simon Schneider ◽

Franka Enow Oben ◽

Isabelle Neumann ◽

...

Keyword(s):

Dna Damage ◽

Gene Editing ◽

Chromatin Condensation ◽

Mammalian Species ◽

Complete Removal ◽

Sperm Chromatin ◽

Male Mice ◽

Specific Proteins ◽

Species Specific

Protamines are unique sperm-specific proteins that package and protect paternal chromatin until fertilization. A subset of mammalian species expresses two protamines (PRM1 and PRM2), while in others PRM1 is sufficient for sperm chromatin packaging. Alterations of the species-specific ratio between PRM1 and PRM2 are associated with infertility. Unlike PRM1, PRM2 is generated as a precursor protein consisting of a highly conserved N-terminal domain, termed cleaved PRM2 (cP2), which is consecutively trimmed off during chromatin condensation. The carboxyterminal part, called mature PRM2 (mP2), interacts with DNA and mediates chromatin hyper-condensation, together with PRM1. The removal of the cP2 domain is believed to be imperative for proper chromatin condensation and the prevention of DNA damage. Yet, the role of cP2 is not yet understood. Using CRISPR-Cas9 mediated gene editing, we generated mice lacking the cP2 domain while the mP2 is still expressed. We show that deletion of one allele of the cP2 domain is sufficient to render male mice infertile. cP2 deficient sperm show incomplete PRM2 incorporation, retention of transition proteins and a severely altered protamine ratio. During epididymal transit, cP2 deficient sperm seem to undergo ROS mediated degradation leading to complete DNA fragmentation, inviability and immotility of mature sperm. The cP2 domain therefore seems to be necessary for the complex crosstalk leading to the successive and complete removal of transition proteins and complete protamination of sperm chromatin. Overall, we present the first step towards understanding the role of the cP2 domain in paternal chromatin packaging and open up avenues for further research.

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Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

10.26434/chemrxiv.6294941.v1 ◽

2018 ◽

Author(s):

Nicola Molinari ◽

Jonathan P. Mailoa ◽

Boris Kozinsky

Keyword(s):

Polymer Electrolyte ◽

Salt Concentration ◽

Rational Design ◽

Material System ◽

Ion Dynamics ◽

High Concentration ◽

Anion Clusters ◽

Poly Ethylene Oxide ◽

Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

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Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

10.26434/chemrxiv.6294941 ◽

2018 ◽

Author(s):

Nicola Molinari ◽

Jonathan P. Mailoa ◽

Boris Kozinsky

Keyword(s):

Polymer Electrolyte ◽

Salt Concentration ◽

Rational Design ◽

Material System ◽

Ion Dynamics ◽

High Concentration ◽

Anion Clusters ◽

Poly Ethylene Oxide ◽

Poly Ethylene

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Exosomes from human umbilical cord mesenchymal stem cells attenuate the inflammation of severe steroid-resistant asthma by reshaping macrophage polarization

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02244-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Bing Dong ◽

Chao Wang ◽

Jing Zhang ◽

Jinrong Zhang ◽

Yinuo Gu ◽

...

Keyword(s):

Flow Cytometry ◽

Stem Cell ◽

Mesenchymal Stem Cell ◽

Quantitative Proteomics ◽

Macrophage Polarization ◽

Human Umbilical Cord ◽

Raw 264.7 ◽

Steroid Resistant ◽

Central Protein

Abstract Background Severe, steroid-resistant asthma (SSRA) is a serious clinical problem in asthma management. Affected patients have severe clinical symptoms, worsened quality of life, and do not respond to steroid, a mainstay steroid treatment of asthma. Thus, effective therapies are urgently needed. Exosomes derived from mesenchymal stem cell (MSC-Exo) has become attractive candidates for the lung inflammatory diseases through its immunomodulatory effects. In this study, we explored the therapeutic effects of MSC-Exo in SSRA and identified the therapeutic mechanism of MSC-Exo. Method Exosomes from human umbilical cord mesenchymal stem cell (hUCMSC) were isolated and characterized by transmission electron microscopy, nanoparticle tracking analysis and flow cytometry analysis. Effects of MSC-Exo on airway hyper responsiveness (AHR), inflammation, histopathology, and macrophage polarization in SSRA in mice were evaluated. Systematic depletion of macrophages determined the role of macrophages in the therapeutic effect of SSRA in mice. LPS-stimulated RAW 264.7 cell model was constructed to determine the underlying mechanism of MSC-Exo on macrophage polarization. qRT-PCR, Western blotting, immunofluorescence, and flow cytometry were performed to evaluate the expression of M1 or M2 markers. Tandem mass tags (TMT)-labeled quantitative proteomics were applied to explore the central protein during the regulation effect of MSC-Exo on macrophage polarization. Knockdown and overexpression of TRAF1 were used to further clarify the role of the central protein on macrophage polarization. Result We successfully isolated and characterized exosomes from hUCMSCs. We verified that the intratracheal administration of MSC-Exo reversed AHR, histopathology changes, and inflammation in SSRA mice. Systematic depletion of macrophages weakened the therapeutic effect of MSC-Exo. We found that MSC-Exo treatment inhibited M1 polarization and promoted M2 polarization in LPS-stimulated RAW 264.7 cells. Subsequently, tumor necrosis factor receptor-associated factor 1 (TRAF1) was determined as the central protein which may be closely related to the regulation of macrophage polarization from TMT-labeled quantitative proteomics analysis. Knockdown and overexpression of TRAF1 demonstrated that the effect of MSC-Exo treatment on macrophage polarization, NF-κB and PI3K/AKT signaling was dependent on TRAF1. Conclusion MSC-Exo can ameliorate SSRA by moderating inflammation, which is achieved by reshaping macrophage polarization via inhibition of TRAF1.

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Pannexins and Connexins: Their Relevance for Oocyte Developmental Competence

International Journal of Molecular Sciences ◽

10.3390/ijms22115918 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5918

Author(s):

Paweł Kordowitzki ◽

Gabriela Sokołowska ◽

Marta Wasielak-Politowska ◽

Agnieszka Skowronska ◽

Mariusz T. Skowronski

Keyword(s):

Assisted Reproductive Technologies ◽

Mammalian Species ◽

Atp Release ◽

Reproductive Technologies ◽

High Energy ◽

Developmental Competence ◽

Physiological Processes ◽

Protein Group ◽

Multicellular Organisms

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.

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Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Cancers ◽

10.3390/cancers13092036 ◽

2021 ◽

Vol 13 (9) ◽

pp. 2036

Author(s):

Luigi Marongiu ◽

Markus Burkard ◽

Sascha Venturelli ◽

Heike Allgayer

Keyword(s):

Structural Damage ◽

Folk Medicine ◽

Gastrointestinal Diseases ◽

Potential Contribution ◽

Anticancer Properties ◽

Specific Phage ◽

Microbial Network ◽

Inflammatory Bowel ◽

Species Specific

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.

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Species-Specific Regulation of TRPM2 by PI(4,5)P2 via the Membrane Interfacial Cavity

International Journal of Molecular Sciences ◽

10.3390/ijms22094637 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4637

Author(s):

Daniel Barth ◽

Andreas Lückhoff ◽

Frank J. P. Kühn

Keyword(s):

Amino Acid Residues ◽

Hek 293 ◽

Complete Inactivation ◽

293 Cells ◽

Activation Mechanisms ◽

Specific Regulation ◽

Species Specific ◽

Inside Out ◽

Positively Charged

The human apoptosis channel TRPM2 is stimulated by intracellular ADR-ribose and calcium. Recent studies show pronounced species-specific activation mechanisms. Our aim was to analyse the functional effect of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), commonly referred to as PIP2, on different TRPM2 orthologues. Moreover, we wished to identify the interaction site between TRPM2 and PIP2. We demonstrate a crucial role of PIP2, in the activation of TRPM2 orthologues of man, zebrafish, and sea anemone. Utilizing inside-out patch clamp recordings of HEK-293 cells transfected with TRPM2, differential effects of PIP2 that were dependent on the species variant became apparent. While depletion of PIP2 via polylysine uniformly caused complete inactivation of TRPM2, restoration of channel activity by artificial PIP2 differed widely. Human TRPM2 was the least sensitive species variant, making it the most susceptible one for regulation by changes in intramembranous PIP2 content. Furthermore, mutations of highly conserved positively charged amino acid residues in the membrane interfacial cavity reduced the PIP2 sensitivity in all three TRPM2 orthologues to varying degrees. We conclude that the membrane interfacial cavity acts as a uniform PIP2 binding site of TRPM2, facilitating channel activation in the presence of ADPR and Ca2+ in a species-specific manner.

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