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Copyright of Journal of Soil Science & Plant Nutrition / Toprak Bilimi ve Bitki Besleme Dergisi is the property of Soil Science Society of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abnormal calcium homeostasis, activation of protease calpain, generation of p25 and hyperactivation of cyclin-dependent kinase 5 (Cdk5) have all been implicated in the pathogenesis of neurogenerative diseases including Alzheimer's disease. We have recently shown that extracellular cold-inducible RNA-binding protein (eCIRP) induces Cdk5 activation via p25. However, the precise molecular mechanism by which eCIRP regulates calcium signaling and calpain remains to be addressed. We hypothesized that eCIRP regulates p25 via Ca2+-dependent calpain activation. eCIRP increased calpain activity and decreased the endogenous calpain inhibitor calpastatin in Neuro 2a (N2a) cells. Calpain inhibition with calpeptin attenuated eCIRP-induced calpain activity and p25. eCIRP specifically upregulated cytosolic calpain 1, and calpain 1 silencing attenuated the eCIRP-induced increase in p25. eCIRP stimulation increased cytosolic free Ca2+, especially in hippocampal neuronal HT22 cells, which was attenuated by the eCIRP inhibitor Compound 23 (C23). Endoplasmic reticulum (ER) inositol 1,4,5-trisphosphate receptor (IP3R) inhibition using 2-aminoethoxy-diphenyl-borate or xestospongin-C (X-C), interleukin-6 receptor alpha (IL-6Rα)-neutralization, and phospholipase C (PLC) inhibition with U73122 attenuated eCIRP-induced Ca2+ increase, while Ca2+ influx across the plasma membrane remained unaffected by eCIRP. Finally, C23, IL-6Rα antibody, U73122 and X-C attenuated eCIRP-induced p25 in HT-22 cells. In conclusion, the current study uncovers eCIRP-triggered Ca2+ release from ER stores in an IL-6Rα/PLC/IP3-dependent manner as a novel molecular mechanism underlying eCIRP's induction of Cdk5 activity and potential involvement in neurodegeneration. [ABSTRACT FROM AUTHOR]

Jana Bacova,1 Petr Knotek,2 Katerina Kopecka,2 Ludek Hromadko,3 Jan Capek,1 Pavlina Nyvltova,1 Lenka Bruckova,1 Ladislava Schröterova,4 Blanka Sestakova,4 Jiri Palarcik,5 Martin Motola,3 Dana Cizkova,6 Ales Bezrouk,7 Jiri Handl,1 Zdenek Fiala,8 Emil Rudolf,4 Zuzana Bilkova,1 Jan M Macak,3,9 Tomas Rousar1 1Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic; 2Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic; 3Center of Materials and Nanotechnologies, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic; 4Department of Medical Biology and Genetics, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic; 5Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic; 6Department of Histology and Embryology, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic; 7Department of Medical Biophysics, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic; 8Department of Preventive Medicine, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic; 9Central European Institute of Technology, Brno University of Technology, Brno, Czech RepublicCorrespondence: Tomas Rousar, Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic, Tel +420 466 037 707, Fax +420 466 036 361, Email Tomas.Rousar@upce.czPurpose: Titanium dioxide nanoparticles, 25 nm in size of crystallites (TiO2 P25), are among the most produced nanomaterials worldwide. The broad use of TiO2 P25 in material science has implied a request to evaluate their biological effects, especially in the lungs. Hence, the pulmonary A549 cell line has been used to estimate the effects of TiO2 P25. However, the reports have provided dissimilar results on caused toxicity. Surprisingly, the physicochemical factors influencing TiO2 P25 action in biological models have not been evaluated in most reports. Thus, the objective of the present study is to characterize the preparation of TiO2 P25 for biological testing in A549 cells and to evaluate their biological effects.Methods: We determined the size and crystallinity of TiO2 P25. We used four techniques for TiO2 P25 dispersion. We estimated the colloid stability of TiO2 P25 in distilled water, isotonic NaCl solution, and cell culture medium. We applied the optimal dispersion conditions for testing the biological effects of TiO2 P25 (0– 100 μg.mL− 1) in A549 cells using biochemical assays (dehydrogenase activity, glutathione levels) and microscopy.Results: We found that the use of fetal bovine serum in culture medium is essential to maintain sufficient colloid stability of dispersed TiO2 P25. Under these conditions, TiO2 P25 were unable to induce a significant impairment of A549 cells according to the results of biochemical and microscopy evaluations. When the defined parameters for the use of TiO2 P25 in A549 cells were met, similar results on the biological effects of TiO2 P25 were obtained in two independent cell laboratories.Conclusion: We optimized the experimental conditions of TiO2 P25 preparation for toxicity testing in A549 cells. The results presented here on TiO2 P25-induced cellular effects are reproducible. Therefore, our results can be helpful for other researchers using TiO2 P25 as a reference material.Keywords: titanium dioxide, nanoparticles, P25, nanotoxicity, A549 cells, dispersion

This work deals with the preparation of TiO2 nanoparticulate layers of various mass (0.05 mg/cm2 to 2 mg/cm2) from three commercial nanopowder materials, P90, P25 and CG 300, their characterisation (profilometry, BET and SEM) and evaluation of their photocatalytic activity in the gaseous phase in a flow-through photoreactor according to the ISO standard (ISO 22197-2). Hexane was chosen as a single model pollutant and a mixture of four compounds, namely acetaldehyde, acetone, heptane and toluene was used for the evaluation of the efficiency of simultaneous removal of several pollutants. A linear dependence between the layer mass and the layer thickness for all materials was found. Up to a layer mass 0.5 mg/cm2, the immobilisation P90 and P25 powder did not result in a decrease in BET surface area, whereas with an increase in layer mass to 1 mg/cm2, a decrease of the BET surface was observed, being more significant in the case of P90. The photocatalytic conversion of hexane was comparable for all immobilised powders up to a layer mass of 0.5 mg/cm2. For higher layer mass, the photocatalytic conversion of hexane on P25 and P90 differ; the latter achieved about 30% higher conversion. In the case of the simultaneous degradation of four compounds, acetaldehyde was degraded best, followed by acetone and toluene; the least degraded compound was heptane. The measurement of released CO2 revealed that 90% of degraded hexane was mineralised to CO2 and water while for a mixture of 4 VOCs, the level of mineralisation was 83%. [ABSTRACT FROM AUTHOR]

Ghana is currently experiencing stagnant agricultural growth as a result of significant differences between actual and potential crop productivity. Village Savings and Loans Associations (VSLAs) are essential in bringing financial services to rural areas where access is scarce. The study investigates smallholder women groundnut farmers’ participation in Village Savings and Loans Association (VSLA) programme and its impact on farm productivity and income in Northern Ghana. The data was collected from 384 smallholder women groundnut farmers using multistage sampling technique and analyzed using descriptive statistics, Endogenous switching regression (ESR), Propensity Score Matching (PSM) and Kendall’s Coefficient of Concordance. The findings of the ESR showed that membership of Farmer Based Organization (FBO), radio ownership and dependency ratio positively influenced the probability of women groundnut farmers’ participation in the VSLA programme. However, extension services, years of living in the community, groundnut farming experience, farm size and input cost have negative influence on women farmers’ participation in the VSLA programme. In addition, the results of the ESR and PSM showed that VSLA programme participation significantly increased participants’ farm productivity and income. The small amount of available loans and short-term loan period were major challenges faced by the VSLA programmes and these limited investments in long-term activities. The study therefore suggests that VSLAs should tailor their savings and lending modalities to the needs of the farmers. To overcome the delivery challenges of VSLA credit, women groundnut farmers should use part of their loans from the VSLA programme to start off-farm income generating activities.

A reduced graphene oxide-P25 (rGO-P25) composite was synthesized by one-step hydrothermal method. The photocatalytic degradation of Rhodamine B (RhB) by the rGO-P25 composite and its settling performance was investigated with P25 as a control. The results showed that the rGO-P25 composite has a mesoporous structure, with the average particle size increased from 4.99 to 399.0 µm, and the specific surface area of the composite increased from 54.0 to 74.3 m2/g. The rGO-P25 composite has a much better photocatalytic and settling performance as compared to P25, which were 1.56 and 2.4 times higher. The increased photocatalytic performance by the rGO-P25 composite was mainly attributed to the increased adsorption capacity and charge transfer ability due to the introduction of rGO flakes in the composite. However, the improved settling performance mainly lies on the increase of the average particle size. The electron spin resonance (ESR) results shows that hydroxyl radical, superoxide radical and photogenerated hole were all generated in the degradation of RhB but the hydroxyl radicals are the leading reactive oxygen species. The as-synthesized rGO-P25 composite showed a good recycling ability as RhB degradation rate could still reach 98.6% after five times reuse. This study indicates that the rGO-P25 composite is a promising photocatalyst for practical wastewater treatment. [ABSTRACT FROM AUTHOR]

Aberrant expression of cyclin-dependent kinase 5 (Cdk5) has been reported in pituitary adenomas. However, the role of Cdk5 in the tumorigenesis remains unclear. We show that prenatal p25-activated Cdk5 phosphorylates minichromosome maintenance protein 2 (Mcm2), enhancing minichromosome maintenance (MCM) family proteins and driving intermediate lobe-located melanotrope-originated pituitary tumorigenesis. In a mouse model with CaMKII promoter-driven transgenic induction of p25, we observed intermediate lobe-originated pituitary adenoma producing non-functional proopiomelanocortin (POMC)-derived peptides under persistent p25 overexpression. Single-cell RNA sequencing revealed Mcm2 may play an important role during tumor progression. Subsequently, Mcm2 was identified as a potential phosphorylated substrate of Cdk5, mediating the tumorous proliferation of melanotrope cells. Silencing Cdk5 or Mcm2 suppressed cell proliferation and colony formation in the 293T cell lines. Therefore, our findings provide a new mouse model of intermediate lobe-originated pituitary adenoma induced by p25/Cdk5 and unveil a previously unappreciated role of Cdk5 and Mcm2 in pituitary adenoma tumorigenesis. Graphical abstract of Cdk5/p25 phosphorylation of Mcm2, promoting DNA replication and pituitary tumorigenesis in p25OE mice and human adenomas. [Display omitted] [ABSTRACT FROM AUTHOR]

The accumulation of proteins in filter membranes limits the efficiency of filtering technologies for cleaning wastewater. Efforts are ongoing to coat commercial filters with different materials (such as titanium dioxide, TiO2) to reduce the fouling of the membrane. Beyond monitoring the desired effect of the retention of biomolecules, it is necessary to understand what the biophysical changes are in water-soluble proteins caused by their interaction with the new coated filter membranes, an aspect that has received little attention so far. Using spin-label electron paramagnetic resonance (EPR), aided with native fluorescence spectroscopy and dynamic light scattering (DLS), here, we report the changes in the structure and dynamics of bovine serum albumin (BSA) exposed to TiO2 (P25) nanoparticles or passing through commercial polyvinylidene fluoride (PVDF) membranes coated with the same nanoparticles. We have found that the filtering process and prolonged exposure to TiO2 nanoparticles had significant effects on different regions of BSA, and denaturation of the protein was not observed, neither with the TiO2 nanoparticles nor when passing through the TiO2-coated filter membranes.