K+(Rb+) and Ca2+ fluxes in young winter wheat plants exposed to sub-zero temperatures

Ice crystal formation temperature was determined in the region of the crown in one group of 7-day-old intact unhardened high-salt plants of winter wheat (Triticum aestivum L. cv. Weibulls Starke II) with TA (Thermal Analysis) and DTA (Differential Thermal Analysis) methods. After exposure of another group of plants, grown for the first 7 days in the same way as the first group, to various sub-zero temperatures (-1 to 5°C), influx in roots of Rb⁺(⁸⁶Rb⁺) and Ca²⁺(⁴⁵Ca²⁺) and contents of K⁺ and Ca²⁺ were determined at intervals during 7 days of recovery. Ice crystal formation in the crown tissue was probably extracellular and took place at about -4°C. There was a large loss of K⁺ from the roots after treatment at sub-zero temperatures. This loss increased as the temperature of the sub-zero treatment decreased. During recovery, roots of plants exposed to -1, -2 and -3°C gradually reabsorbed K⁺. Reabsorption of K⁺ in roots of plants exposed to -4°C was greatly impaired. Rb⁺ influx decreased and Ca²⁺ influx increased after sub-zero temperature treatments of the plants. Active Rb⁺ influx mechanisms and active extrusion of Ca²⁺ were impaired or irreversibly damaged by the exposure. While Rb⁺ influx mechanisms were apparently repaired during recovery in plants exposed to temperatures down to -3°C, Ca²⁺ extrusion mechanisms were not. The temperature for ice crystal formation in the region of the crown tissue coincides with the temperature at which the plants lost the ability to reabsorb K⁺ and to repair Rb⁺ influx mechanisms during the recovery period. Plants were lethally damaged at temperatures below ?4°C.     

Gasdermin D maintains bone mass by rewiring the endo-lysosomal pathway of osteoclastic bone resorption

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ATM regulates Cdt1 stability during the unperturbed S phase to prevent re-replication

Ataxia-telangiectasia mutated (ATM) plays crucial roles in DNA damage responses, especially with regard to DNA double-strand breaks (DSBs). However, it appears that ATM can be activated not only by DSB, but also by some changes in chromatin architecture, suggesting potential ATM function in cell cycle control. Here, we found that ATM is involved in timely degradation of Cdt1, a critical replication licensing factor, during the unperturbed S phase. At least in certain cell types, degradation of p27^Kip1 was also impaired by ATM inhibition. The novel ATM function for Cdt1 regulation was dependent on its kinase activity and NBS1. Indeed, we found that ATM is moderately phosphorylated at Ser1981 during the S phase. ATM silencing induced partial reduction in levels of Skp2, a component of SCF^Skp2 ubiquitin ligase that controls Cdt1 degradation. Furthermore, Skp2 silencing resulted in Cdt1 stabilization like ATM inhibition. In addition, as reported previously, ATM silencing partially prevented Akt phosphorylation at Ser473, indicative of its activation, and Akt inhibition led to modest stabilization of Cdt1. Therefore, the ATM-Akt-SCF^Skp2 pathway may partly contribute to the novel ATM function. Finally, ATM inhibition rendered cells hypersensitive to induction of re-replication, indicating importance for maintenance of genome stability.     

Small Molecular Inhibitors Block TRPM4 Currents in Prostate Cancer Cells,with Limited Impact on Cancer Hallmark Functions

Transient receptor potential melastatin 4 (TRPM4) is a broadly expressed Ca²⁺ activated monovalent cation channel that contributes to the pathophysiology of several diseases.For this study, we generated stable CRISPR/Cas9 TRPM4 knockout (K.O.) cells from the human prostate cancer cell line DU145 and analyzed the cells for changes in cancer hallmark functions. Both TRPM4-K.O. clones demonstrated lower proliferation and viability compared to the parental cells. Migration was also impaired in the TRPM4-K.O. cells. Additionally, analysis of 210 prostate cancer patient tissues demonstrates a positive association between TRPM4 protein expression and local/metastatic progression. Moreover, a decreased adhesion rate was detected in the two K.O. clones compared to DU145 cells.Next, we tested three novel TRPM4 inhibitors with whole-cell patch clamp technique for their potential to block TRPM4 currents. CBA, NBA and LBA partially inhibited TRPM4 currents in DU145 cells. However, none of these inhibitors demonstrated any TRPM4-specific effect in the cellular assays.To evaluate if the observed effect of TRPM4 K.O. on migration, viability, and cell cycle is linked to TRPM4 ion conductivity, we transfected TRPM4-K.O. cells with either TRPM4 wild-type or a dominant-negative mutant, non-permeable to Na⁺. Our data showed a partial rescue of the viability of cells expressing functional TRPM4, while the pore mutant was not able to rescue this phenotype. For cell cycle distribution, TRPM4 ion conductivity was not essential since TRPM4 wild-type and the pore mutant rescued the phenotype.In conclusion, TRPM4 contributes to viability, migration, cell cycle shift, and adhesion; however, blocking TRPM4 ion conductivity is insufficient to prevent its role in cancer hallmark functions in prostate cancer cells.     

Evolutionary assembly of cooperating cell types in an animal chemical defense system

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Les Pseudholaster (Echinoidea,Holasteroida) du Crétacé de France

In the order of Holasteroida, the fossil record highlights a contradiction between the genus Pseudholaster that appears in the Aptian, whose plastron is prostostern close to the Jurassic ancestors and the genus Holaster, which appears in the Valanginian, whose meridostern plastron appears more derived. This inconsistency can be explained by the ignorance of the plastronal architecture on the part of the early authors. A review of the species of Pseudholaster from the Cretaceous period of France was therefore carried out. The objective was to statistically determine the discriminating morphological characters, and to study the modifications of the architecture of the interambulacrum 5 of the French species belonging to this genus, as well as to the species included in the genus Holaster incorrectly by earlier authors. This review of the species of the genus Pseudholaster begins with a study of the ontogeny of the species Holaster intermedius Münster in Goldfuss, 1826–1833, first representative of the genus Pseudholaster, which appears in the Hauterivian in the Parisian and Rhodano-vocontian basins. The modifications during growth concern the overall shape, but also the plastron architecture: the number of plastron plates increases while the number of plates located between the peristome and the periproct remains fixed. The plastron of this species is protosternal and not meridosternal as Lambert pointed out. The labrum is cupuliform in contact with the second sternal 5a2 by a narrow digitation. However, this arrangement differs from that observed on a protosternal breastplate. This apomorphism of the plastron plate pattern, called “labrotaxienne”, is found in all the Pseudholaster studied, and the study of the architecture of the interambulacrum 5 also reveals a gradual decrease in the number of preanal plates between the oldest (Hauterivian) and the younger (Cenomanian-Lower Turonian) species studied. Most of the French species have been revised, with some synonyms. A new species, P. neraudeaui, is the last known Pseudholaster dated from the upper Cenomanian and lower Turonian of southwestern France. Our study illustrates the evolution of the genus Pseudholaster between the Hauterivian and the early Turonian in France. The interest of the study is to show that the appearance of the genus Pseudholaster is older than that of the genus Holaster. Pseuholaster intermedius, of Hauterivian age, possesses a derived protostern plastron called here “labrotaxien” and not meridostern as defined historically by Lambert, and to reveal that the number of preanals decreases over geological time. This data is essential for future phylogenetic studies. On a palaeobiogeographical level, the study reveals the expansion of the genus Pseudholaster during early Cretaceous in western Europe, with diversification during the Albian, its disappearance during late Cenomanian in the Paris basin while it still persists in the Aquitain basin, its predilection for circalitoral environments.     

Effects of detergents on catalytic activity of human endometase/matrilysin 2, a putative cancer biomarker

Matrix metalloproteinases (MMPs) are a family of hydrolytic enzymes that play significant roles in development, morphogenesis, inflammation, and cancer invasion. Endometase (matrilysin 2 or MMP-26) is a putative early biomarker for human carcinomas. The effects of the ionic and nonionic detergents on catalytic activity of endometase were investigated. The hydrolytic activity of endometase was detergent concentration dependent, exhibiting a bell-shaped curve with its maximum activity near the critical micelle concentration (CMC) of nonionic detergents tested. The effect of Brij-35 on human gelatinase B (MMP-9), matrilysin (MMP-7), and membrane-type 1 MMP (MT1-MMP) was further explored. Their maximum catalysis was observed near the CMC of Brij-35 (∼ 90 μM). Their IC₅₀ values were above the CMC. The inhibition mechanism of MMP-7, MMP-9, and MT1-MMP by Brij-35 was a mixed type as determined by Dixon’s plot; however, the inhibition mechanism of endometase was noncompetitive with a K_i value of 240 μM. The catalytic activities of MMPs are influenced by detergents. Monomer of detergents may activate and stabilize MMPs to enhance catalysis, but micelle of detergents may sequester enzyme and block the substrate binding site to impede catalysis. Under physiological conditions, a lipid or membrane microenvironment may regulate enzymatic activity.     

Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets

Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources.     

Biotic and abiotic determinants of the formation of ant mosaics in primary Neotropical rainforests

1. Ants are widespread in tropical rainforests, including in the canopy where territorially dominant arboreal species represent the main part of the arthropod biomass. 2. By mapping the territories of dominant arboreal ant species and using a null model analysis and a pairwise approach this study was able to show the presence of an ant mosaic on the upper canopy of a primary Neotropical rainforest (c. 1 ha sampled; 157 tall trees from 28 families). Although Neotropical rainforest canopies are frequently irregular, with tree crowns at different heights breaking the continuity of the territories of dominant ants, the latter are preserved via underground galleries or trails laid on the ground. 3. The distribution of the trees influences the structure of the ant mosaic, something related to the attractiveness of tree taxa for certain arboreal ant species rather than others. 4. Small‐scale natural disturbances, most likely strong winds in the area studied (presence of canopy gaps), play a role by favouring the presence of two ant species typical of secondary formations: Camponotus femoratus and Crematogaster levior, which live in parabiosis (i.e. share territories and nests but lodge in different cavities) and build conspicuous ant gardens. In addition, pioneer Cecropia myrmecophytic trees were recorded.     

M(en)TORship lessons on life and death by the integrated stress response

Cells employ pro-survival and pro-adaptive pathways to cope with different forms of environmental stress. When stress is excessive, and the damage caused by it is unsustainable, cells engage pro-death pathways, which are in place to protect the host from the deleterious effects of harmed cells. Two important pathways that determine the balance between survival and death of stressed cells are the integrated stress response (ISR) and the mammalian target of rapamycin (mTOR), both of which converge at the level of mRNA translation. The two pathways have established avenues of communication to control their activity and determine the fate of stressed cells in a context-dependent manner. The functional interplay between the ISR and mTOR may have significant ramifications in the development and treatment of human diseases such as diabetes, neurodegeneration and cancer.