Normal Conditions Research Articles

Disruption of the OsWRKY71 transcription factor gene results in early rice seed germination under normal and cold stress conditions

Abstract Background Early seed germination in crops can confer a competitive advantage against weeds and reduce the time to maturation and harvest. WRKY transcription factors regulate many aspects of plant development including seed dormancy and germination. Both positive and negative regulators of seed germination have been reported in many plants such as rice and Arabidopsis. Using a transient expression system, we previously demonstrated that OsWRKY71 is a negative regulator of gibberellin (GA) signaling in aleurone cells and likely forms a “repressosome” complex with other transcriptional repressors. Hence, it has the potential to impact seed germination properties. Results In this study, we demonstrate that OsWRKY71, a Group IIa WRKY gene, appeared at the same time as seed-bearing plants. Rice mutants lacking OsWRKY71 have seeds and embryos that germinate earlier than wildtype controls. In oswrky71 aleurone layers, α-amylase activity was hypersensitive to stimulation by GA3 and hyposensitive to inhibition by abscisic acid (ABA). Early germination in oswrky71 intact seeds was also hyposensitive to ABA. Transcriptomic profiling during embryo germination and early post-germination growth demonstrates that OsWRKY71 influences the expression of 9–17% of genes in dry and imbibing embryos. Compared to wildtype embryos, the mutant transcriptomes have large temporal shifts at 4, 8 and 12 h after imbibition (HAI). Importantly, many genes involved in the ABA-dependent inhibition of seed germination were downregulated in oswrky71-1. This mutant also displayed altered expression of multiple ABA receptors (OsPYLs/RCARs) that control ABA signaling and the VP1-SDR4-DOG1L branch of ABA signaling that promotes seed dormancy. Association studies reveal an OsWRKY71-containing quantitative trait locus involved in low-temperature seed germinability, qLTG-2. Indeed, oswrky71 seeds germinated early at 15 °C. Conclusions Rice Group-IIa WRKY transcription factor OsWRKY71 is a master regulator of germination that influences the expression of 9–17% of genes in dry and imbibing embryos. It is also most likely the primary candidate of low-temperature seed germinability QTL, qLTG-2. We propose that knockouts of OsWRKY71 can generate rice varieties with improved germination properties under normal or low-temperature conditions.

Вплив червоного та синього електромагнітного випромінювання на каталазну активність зародків в’юна Misgurnus fossilis L.

Photobiomodulation therapy is widely used to treat various pathological conditions. This therapy is based on the use of monochromatic light radiation. The light of the visible spectrum induces different biological effects at the molecular and cellular levels, both therapeutic and toxic. The obtained effect depends on the length of radiation, exposure, etc. One of the possible mechanisms of such influence is the regulation of pro-oxidant-antioxidant homeostasis. In order to clarify the mechanism of action of electromagnetic radiation (EMR) of different spectral composition, catalase (CAT) activity was investigated in germ cells of loach Misgurnus fossilis L. during embryogenesis. Since, loach embryos are an adequate system that reflects the physiological state of the cell both under normal conditions and as a result of the influence of various pharmacological, physical and chemical agents. The resulting zygotes were irradiated (10 min) with blue and red LEDs (λ = 460 and 660 nm, respectively). The activity of CAT was determined by the ability of hydrogen peroxi­de to form a stable colored complex with molybdenum salts. It was established that EMR of the red spectrum has the most pronounced biological effects and caused significant changes in catalase activity during embryogenesis relative to control and blue light. The maximum increase of the indicator occurs at the stage of 16 blastomeres, and at the stage of 8 and 10 divisions, a gradual decrease in enzymatic activity is observed. Irradiation by the light of the blue spectrum lasting 10 min did not cause significant changes in catalase activi­ty relative to the control at the early stages of loach embryogenesis. The obtained results suggest that CAT, one of the key enzymes of the antioxidant defense system, undergoes photoactivation under the influence of red light.

Evolutionary conservation and metabolic significance of autophagy in algae.

Autophagy is a highly conserved 'self-digesting' mechanism used in eukaryotes to degrade and recycle cellular components by enclosing them in a double membrane compartment and delivering them to lytic organelles (lysosomes or vacuoles). Extensive studies in plants have revealed how autophagy is intricately linked to essential aspects of metabolism and growth, in both normal and stress conditions, including cellular and organelle homeostasis, nutrient recycling, development, responses to biotic and abiotic stresses, senescence and cell death. However, knowledge regarding autophagic processes in other photosynthetic organisms remains limited. In this review, we attempt to summarize the current understanding of autophagy in algae from a metabolic, molecular and evolutionary perspective. We focus on the composition and conservation of the autophagy molecular machinery in eukaryotes and discuss the role of autophagy in metabolic regulation, cellular homeostasis and stress adaptation in algae. This article is part of the theme issue 'The evolution of plant metabolism'.

Respiratory system mechanics during noninvasive proportional assist ventilation: A model study

AbstractPurposeTo assess the accuracies of airway resistance (Raw) and compliance (Crs) calculations using the expiratory time constant (RCexp) method as well as the accuracy of Pmus estimation in obstructive lung models.MethodsA Respironics V60 ventilator was connected to an active lung simulator. The driving pressure was maintained at 5–10 cmH2O and positive end-expiration pressure (PEEP) was 5 cmH2O. Maximal Pmus, estimated based on equations of motion and respiratory mechanical properties, was calculated by the RCexp method to derive respiratory system compliance (Crs) and inspiratory (Rinsp) and expiratory (Rexp) resistance.ResultsDuring PAV, the assist proportion was adjusted to 55% and 40% with Pmus of 5 and 10 cmH2O, respectively. Pmus measurement errors were <20% of the preset values in most lung conditions. In the active lung model with PAV, an overestimation of Raw was found in the normal resistance condition, and Rinsp was underestimated in the severe obstructive model (P < 0.01). Crs was overestimated significantly except in the severe obstructive model at a Pmus of 10 cmH2O (all P < 0.01). Using the RCexp method, the target of ≤20% between the calculated and preset values in airway resistance was achieved in most obstructive models at a Pmus of 5 cmH2O.ConclusionsThe RCexp method might provide real-time assessments of respiratory mechanics (elastance and resistance) in the PAV mode. With low inspiratory effort, the estimation error was acceptable (<20%) in most obstructive lung models.

LcASR enhances tolerance to abiotic stress in Leymus chinensis and Arabidopsis thaliana by improving photosynthetic performance

SUMMARYAs a crucial forage grass, Leymus chinensis plays significant roles in soil and water conservation owing to its robust stress resistance. However, the underlying molecular mechanisms of its stress tolerance remain unclear. In this study, a novel gene, designated as LcASR (Abiotic Stress Resistance in Leymus chinensis), imparting resilience to both high light and drought, was identified. Under normal growth conditions, heterologous overexpression of LcASR in Arabidopsis (HO lines) showed no significant difference in appearance compared to wild‐type. Nevertheless, HO lines accumulate significantly higher chlorophyll content during the dark‐to‐light transition compared to the wild‐type, indicating that the LcASR protein participates in chlorophyll synthesis during chloroplast development. Meanwhile, transgenic Arabidopsis and L. chinensis plants exhibited resistance to abiotic stresses such as high light and drought. Photosystem complexes analysis revealed that LHCII proteins remained stable within their respective complexes during high light stress. We hypothesize that LcASR may play a role in fine tuning of chlorophyll synthesis to enable plant adaptation to diverse stress conditions. Moreover, overexpression of LcASR in L. chinensis led to agronomically valuable traits such as deeper green color, higher biomass accumulation, prolonged withering period, and extended grazing durations. This study uncovers a novel gene in L. chinensis that enhances forage yield and provides valuable genetic resources for sheepgrass breeding.

Vasoactive Intestinal Peptide (VIP) and its Receptors in Adipose Tissue: Implications for Cold Stress Adaptation.

Adipose tissue represents an organ that is highly dynamic and contributes toward vital survival events such as immune responses, lactation, metabolism fuel, and thermogenesis. Data emerging from recent studies support the notion of adipose tissue being organized into a complex system characterized by a discrete anatomy, elevated physiological plasticity, and specific vascular and nerve supplies. Vasoactive intestinal peptide (VIP), along with its receptors, type 1 (VPAC1) and type 2 (VPAC2), has been implicated in various physiological and pathophysiological processes. However, studies on VIP and its receptors in adipose tissue are limited. To explore VIP's presence and activity, as well as its adipose tissue-based receptors, we conducted a study on isolated adipocytes and adipose tissue from inguinal white adipose tissue (WAT) and interscapular brown adipose tissue (BAT) in normal and cold-stressed rats. Our findings indicate the presence of the gene expression VIP and VPAC1 in both WAT and BAT under normal conditions, while VPAC2 was absent. In both WAT and BAT, cold exposure upregulated VIP gene expression. However, the response of VIP receptors to cold exposure is controversial. VPAC2 gene expression was induced in both WAT and BAT, while VPAC1 gene expression presented no change of significance in BAT and a slight reduction in WAT. Additionally, VIP, VPAC1, and VPAC2 proteins were identified from Western blot studies on white and brown adipocytes. After exposure to cold there was an increase of significance in the VIP, VPAC1, and VPAC2 protein levels. This study provides novel insights into how VIP and its receptors alter gene expression and protein levels in adipose tissue and adipocytes during cold stress, indicating their potential involvement in adipose tissue regulation. The findings propose VIP's potentially crucial role in adipose tissue's adaptation to cold stress by affecting the metabolic and biochemical functions of subcutaneous and interscapular adipocytes, with potentially significant implications in the context of developing therapies targeting metabolic disorders.

Soluble αβ-tubulins reversibly sequester TTC5 to regulate tubulin mRNA decay

AbstractMicrotubules, built from heterodimers of α- and β-tubulins, control cell shape, mediate intracellular transport, and power cell division. The concentration of αβ-tubulins is tightly controlled through a posttranscriptional mechanism involving selective and regulated degradation of tubulin-encoding mRNAs. Degradation is initiated by TTC5, which recognizes tubulin-synthesizing ribosomes and recruits downstream effectors to trigger mRNA deadenylation. Here, we investigate how cells regulate TTC5 activity. Biochemical and structural proteomic approaches reveal that under normal conditions, soluble αβ-tubulins bind to and sequester TTC5, preventing it from engaging nascent tubulins at translating ribosomes. We identify the flexible C-terminal tail of TTC5 as a molecular switch, toggling between soluble αβ-tubulin-bound and nascent tubulin-bound states. Loss of sequestration by soluble αβ-tubulins constitutively activates TTC5, leading to diminished tubulin mRNA levels and compromised microtubule-dependent chromosome segregation during cell division. Our findings provide a paradigm for how cells regulate the activity of a specificity factor to adapt posttranscriptional regulation of gene expression to cellular needs.

Evaluating Physiological and Yield Indices of Egyptian Barley Cultivars Under Drought Stress Conditions

Climate change significantly threatens crops, mainly through drought stress, affecting barley, which is essential for food and feed globally. Ten barley cultivars were evaluated under normal and drought stress conditions during the 2019/20 and 2020/21 seasons, focusing on traits such as days to heading and maturity, plant height, number of spikes m−2, spike length, 1000-kernel weight, and biological and grain yield. Drought stress significantly reduced most of these traits. The genotypes showed significant differences in their responses to irrigation treatments, with the interaction between seasons and cultivars also being significant for most traits. The grain yield and 1000-kernel weight were among the least affected traits under drought stress, respectively. Notably, Giza138 and Giza126 showed strong drought tolerance, suitable for drought-resilient breeding. In season one, Giza126, Giza134, and Giza138 yielded 13%, 9%, and 11%, respectively, while Giza135 and Giza129 showed higher reductions at 31% and 39%. In season two, Giza126, Giza134, and Giza138 had reductions of 14%, 10%, and 13%, respectively, while Giza135 and Giza129 again exhibited higher reductions at 31% and 38%. These cultivars also showed strong performance across various stress tolerance indices, including the MP, YSI, STI, GMP, and YI. Giza 134 demonstrated the lowest values for the SDI and TOL, indicating superior drought stress tolerance. On the other hand, Giza 129 and Giza 135 were the most sensitive to drought stress, experiencing significant reductions across critical traits, including 6.1% in days to heading, 18.37% in plant height, 28.21% in number of kernel spikes−1, 38.45% in grain yield, and 34.91% in biological yield. In contrast, Giza 138 and Giza 2000 showed better resilience, with lower reductions in the 1000-kernel weight (6.41%) and grain yield (10.61%), making them more suitable for drought-prone conditions. Giza 126 and Giza 132 also exhibited lower sensitivity, with minimal reductions in days to heading (2%) and maturity (2.4%), suggesting potential adaptability to water-limited environments. Giza 126 maintained the highest root lengths and had the highest stomatal conductance. Giza 138 consistently had the highest chlorophyll content, with SPAD values decreasing to 79% under drought. Despite leading in shoot length, Giza 135 decreased to 42.59% under drought stress. In conclusion, Giza 126 and Giza 138 showed adaptability to water-limited conditions with minimal impact on phenological traits. Giza 126 had the longest roots and highest stomatal conductance, while Giza 138 consistently maintained a high chlorophyll content. Together, they and Giza 134 are valuable for breeding programs to improve barley drought tolerance.

Development of Faba Bean Genotypes for Broomrape Tolerant and Foliar Diseases Resistance in F\(_2\) Factorial Crosses

Two field experiments were conducted at Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt. The first experiment was in a naturally Orobanche- free field and the second one was in a naturally Orobanche-infested field. In each experiment sixteen F2 crosses and their parents were sown. The sixteen F2 crosses were produced by a 4 x 4 factorial mating design in F1 and selfed to give F2-crosses. The data were then analyzed using a line x tester design. The main objective of this study was to develop new promising faba bean genotypes that are able to produce high yield, resistance to foliar diseases and broomrape tolerance. Significant differences among all genotypes mean square were observed for all studied traits under both growth conditions. The parents, crosses and their interaction mean squares were detected for all traits in the two environments. The mean squares of lines were significant and/or highly significant for flowering date and 100-seed weight under both conditions, while number of pods per plant was significant under normal condition, in addition to the number of seeds per plant and broomrape dry weight per plant under infested broomrape condition were significant and highly significant, respectively. Mean squares of testers were significant for chocolate spot at the two conditions; rust disease, plant height, number of pods and seeds, seed yield per plant and 100-seed weight under normal condition. Lines x testers mean squares were significant for all traits in both conditions, except for number of branches and 100-seed weight. L1 and L4 and the parental testers T4 were considered more resistance parents to foliar diseases under both environments. The crosses; L2 x T3, L2 xT4, L3 x T2, L3 x T4 and L4 x T4 were considered resistant to foliar disease and had an earlier flowering date. The testers, T3 and T4 showed significantly the highest values of number of seeds per plant, seed yield per plant and 100-seed weight under both conditions, while the crosses; L3 x T4 and L4 x T4 had the highest values for seed yield per plant and 100-seed weight under both conditions. The parental L2 and T4 were considered good combiners for chocolate spot and rust diseases under both environmental conditions, while L1 and T4 performed as good combiner parents for number of seeds and seed yield per plant. The cross; L2x T3 performed as good specific combiner cross for foliar diseases under both conditions. The crosses; L2x T3, L3xT4, L3 x T1and L4 x T4 had highly significant (sij) values for the No. of seeds and seed yield per plant under infested soil condition. The phenotypic coefficient of variation (PCV) values ranged from 5.52% to 84.01% and genotypic coefficient of variation (GCV) values ranged from 3.18% to 79.21%. Broad-sense heritability (H) ranged from 72.98% to 99.29%, and narrow sense heritability (h2) ranged from 2.3% to 21.38%. Expected genetic advance (Ga) ranged from 0.03 to 0.71, and predicted genetic advance (Ga%) ranged from 8.21% to 10.86%.

Innovative multi-trial breeding and genotype screening in triticale (x Triticosecale Wittmack) for enhanced stability under drought stress.

Triticale is a man-made crop produced by crossing wheat (Triticum aestivum) and rye (Secal cereal) with the aim of increasing the adaptability and potential production of its parental line (wheat) under environmental stresses and harsh conditions. Accordingly, the objectives of this study are as follow, a: compare different stability measurement methods regarding their suitability, b: identify most stable genotypes for cultivar release, and c: provide a freely available package in R programming language (named 'Stbidx') capable of exploiting all stability methods for similar studies. Accordingly, 30 triticale genotypes were evaluated for their stability and adaptability to changing environments during four consecutive years from 2016 to 2020 in different locations in Iran (one year in Zarghan, two years in Ghorveh, one year in Sanandaj) and under two different irrigation regimes (normal irrigation and water deficit stress conditions). All 30 triticale genotypes were cultivated in a randomized complete block design (RCBD) with three replications in each environment (12 environments: 6 trials in 2 conditions). Grain yield of triticale genotypes was measured and it applied to calculate all known stability indices (univariate methods) along with the meta-analysis models were evaluated in this study. Additionally, two novel techniques (Stability ID: SID and AMMI PC Value: APCV) were introduced and successfully tested for screening stable genotypes. These methods were introduced to improve and resolve the limitation of the previous stability methods. Meanwhile, heatmap analysis, as a proper data-mining technique, has been successfully applied for the first time to find stable genotypes in different environments in this study. The results clearly indicated a higher suitability of our introduced methods over previous multi-trials screening methods. Based on our methods and considering all environments, triticale genotypes ELTTCL21 (SID = 8.00; APCV = 28.12), ELTTCL25‌ (SID = 8.14; APCV = 30.02), ELTTCL30 (SID = 8.43; APCV = 17.00), ET-90-8 (SID = 14.00; APCV = 42.05), and Sanabad (SID = 10.57; APCV = 12.44) were among stable genotypes and they can be nominated as new cultivars. Additionally, for stress condition genotypes ELTTCL30 (stress: 380.6g/m2) and ELTTCL18 (stress: 360.79g/m2) and for normal condition genotypes ET-90-4 (normal: 849.4g/m2) and ELTTCL20 (normal:845g/m2) were respectively the most proper genotypes with the highest production to be considered for each condition separately.

Intermittent Hypoxia Impairs Cognitive Function and Promotes Mitophagy and Lysophagy in Obstructive Sleep Apnea-Hypopnea Syndrome Rat Model.

Autophagy regulates intermittent hypoxia (IH)-induced obstructive sleep apnea-hypopnea syndrome (OSAHS). We investigated the effects of IH and its withdrawal on cognitive function, autophagy, and lysophagy in OSAHS. An OSAHS rat model was established, and rats were divided into five groups: normoxia control, IH-4w (4-week IH), IH-6w (6-week IH), IH-8w (8-week IH), and IH-8w + 4w (8-week IH and 4-week normoxia). The cognitive behavior; mitochondrial and lysosomal morphology of the hippocampal tissue; mitochondrial respiratory function, permeability, and membrane potential; lysosomal function; autophagy- and lysophagy-related protein levels; and hypoxia-associated autophagy gene expression in rats were assessed. The cognitive function of rats in the IH-4w, IH-6w, and IH-8w groups was significantly impaired. In IH-8w cells, mitochondrial function was damaged with swollen morphology and decreased quantity, respiration, permeability, and membrane potential, along with significantly increased mitophagy-related protein ATG5 and LC3II/LC3 levels and decreased p62 levels. Expression of hypoxia-associated autophagy genes Becn1, Hif1, Bnip3, Bnip3l, and Fundc1 was significantly higher in the IH-8w group. Significantly increased LAMP2, CTSB, and ACP2 levels in IH-8w cells further indicated impaired lysosomal function. Lysophagy-related protein LAMP1, LC3II/LC3I, and TFEB levels were significantly increased in the IH-8w group, whereas p62 level was significantly decreased. The above listed evidence indicated damage to the mitochondria and lysosomes, as well as stimulation of mitophagy and lysophagy in IH-treatment OSAHS rat model. After withdrawing IH and culturing for 4weeks in normal conditions, the cognitive function of rats improved, and mitophagy and lysophagy decreased. Our findings indicate that IH impairs cognitive function and promotes mitophagy and lysophagy in an OSAHS rat model, and IH withdrawal recovered the above effects.

Low capacitor stress reconfigurable quadratic boost converter with fault tolerant capability for rooftop solar PV application.

Recently, many high-gain topologies have been derived. However, there is a need for a high-gain converter with fault-tolerant features. In this paper, a fault-tolerant reconfigurable quadratic boost converter is proposed for DC microgrid application. In this novel topology, 2-level redundancy is achieved by addressing the fault in the switch and capacitors. The operation of the converter in normal operating conditions and reconfiguration mode is discussed. The derived topology can achieve the same voltage gain even in the reconfiguration mode. The proposed topology exhibits better performance in the reconfiguration state. The voltage stress across the input and output capacitor is reduced in that state. The reliability analysis of capacitors in both states is carried out and compared with the aid of the reliability handbook. Finally, the topology operation in a normal and reconfiguration state is validated by building a 1-kW hardware setup. The results show that the quadratic boost converter in a reconfiguration state operates without altering the voltage gain of the converter and with reduced voltage stress across the capacitors.

The Role of Vitamin D3 Deficiency and Colonization of the Oral Mucosa by Candida Yeast-like Fungi in the Pathomechanism of Psoriasis

Psoriasis is a chronic inflammatory skin disease with complex pathogenesis and variable severity. Performed studies have indicated the impact of vitamin D3 deficiency on the pathogenesis of psoriasis and its severity. However, there is no clear evidence of the influence of the mucosal microbiome on the onset and progression of psoriasis. This review aims to present the current evidence on the role of vitamin D3 and colonization of the oral mucosa by Candida yeast-like fungi in the pathogenesis of psoriasis. Candida albicans is a common yeast that can colonize the skin and mucosal surfaces, particularly in individuals with weakened immune systems or compromised skin barriers. In psoriasis, the skin’s barrier function is disrupted, potentially making patients more susceptible to fungal infections such as Candida. Since patients with psoriasis are at increased risk of metabolic syndrome, they may experience the vicious circle effect in which chronic inflammation leads to obesity. Vitamin D3 deficiency is also associated with microbiological imbalance, which may promote excessive growth of Candida fungi. Under normal conditions, the intestinal and oral microflora support the immune system. Vitamin D3 deficiency, however, leads to disruption of this balance, which allows Candida to overgrow and develop infections.

Histomorphometric analysis of Wharton\'s jelly size in pregnancies with normal and pre-eclamptic conditions, and its relation to baby weight

Multiple factors affect fetal birth weight (FBW) and fetal well-being. This study aims to evaluate how hypertension affects FBW and the area of Wharton's jelly (WJ). It also seeks to explore the protective properties of WJ by analyzing its relationship with FBW in normal and pre-eclamptic (PreE) pregnancies.Eighty umbilical cords (UCs) were analyzed, with forty from normotensive pregnancies and forty from PreE pregnancies. The cross-sectional area of the UC and vessels was measured using a vernier scale and ocular micrometer. The WJ area was calculated by subtracting the vascular area from the UC area, and then compared with FBW.In this study, the normal group had an average FBW of 2547.25 ± 240.79 grams and WJ area of 35.28 ± 8.42 mm, while the PreE group had an average FBW of 2424.75 ± 234.36 grams and WJ area of 29.04 ± 8.09 mm. Both FBW and WJ area were significantly lower in the PreE group. There was a strong positive correlation between WJ area and FBW in both the normal group (r = 0.895, p<0.0001) and the PreE group (r = 0.850, p<0.0001).The findings indicated that both FBW and WJ area were notably lower in the PreE group compared to the normal group. Furthermore, a strong positive correlation between WJ area and FBW was observed in both groups. These results emphasize the importance of WJ in fetal growth and highlight the significance of its quantity in determining birth weight.

Ally or traitor: the dual role of p62 in caspase-2 regulation.

Caspase-2 is a unique and conserved cysteine protease that is involved in several cellular processes, including different forms of cell death, maintenance of genomic stability, and the response to reactive oxygen species. Despite advances in caspase-2 research in recent years, the mechanisms underlying its activation remain largely unclear. Although caspase-2 is activated in the PIDDosome complex, its processing could occur even in the absence of PIDD1 and/or RAIDD, suggesting the existence of an alternative platform for caspase-2 activation. Here, we show that caspase-2 undergoes ubiquitination and interacts with scaffolding protein p62/sequestosome-1 (SQSTM1) under normal conditions and in response to DNA damage. p62 promotes proteasomal but not autophagic caspase-2 degradation as well as its dimerization and activation that triggers the caspase cascade and, subsequently, cell death. Inhibition of p62 expression attenuates cisplatin-induced caspase-2 processing and apoptosis. Notably, the ZZ domain of p62 is critical for caspase-2 binding, whereas the UBA domain is seemingly required to stabilize the p62-caspase-2 complex. Thus, we have uncovered the dual role of p62 in regulating caspase-2 activity: it can foster the degradation of caspase-2 in the proteasome or facilitate its activation by acting as a scaffold platform.

Site-selectively Phosphorylated Hsp90 C-terminal Domain Variants Provide Access to Deciphering the Chaperone Code.

The ubiquitous molecular chaperone Heat shock protein 90 (Hsp90) is pivotal in many cellular processes through folding of client proteins under stressed and normal conditions. Despite intensive research on its function as a chaperone, the influence of posttranslational modifications on Hsp90 (the 'chaperone code'), and its interactions with co-chaperones and client proteins, still remains to be elucidated. The C-terminal domain (CTD) of Hsp90 is essential for formation of the active homodimer state of Hsp90 and contains recognition sites for co-chaperones and client proteins. Here we used expressed protein selenoester ligation to introduce site-selective phosphorylations in the Hsp90 CTD, while preserving the native amino acid sequence. The two phosphorylations do not affect the overall secondary structure, but in combination, slightly decrease the thermal stability of the CTD. The Hsp90 CTD functions as a chaperone in decreasing aggregation of model client proteins, but the C-terminal phosphorylations do not significantly alter the anti-aggregation activity for these clients. The optimization of expressed protein selenoester ligation to carry out several steps in one pot provides an efficient route to access site-specifically modified Hsp90 CTD variants, allowing the generation of Hsp90 variants with site-specific PTMs to decipher the chaperone code.

Cinnamaldehyde induces a TRPA1-mediated nociceptive behavior in planarians.

Nociception is defined as "the neural process of encoding noxious stimuli" by the International Association for the Study of Pain (IASP). Nociception relies on detecting noxious stimuli arising from a potentially or actually tissue-damaging event via specialized cells called nociceptors. In planarians, nociceptive behavior is often indicated by a 'scrunching' gait, in contrast to the usual gliding behavior displayed in normal conditions. The present study extends our previous study Reho et al. (2024) by testing a new potentially irritant molecule, Cinnamaldehyde (CA), which could induce scrunching gaits. We reproduced the nociceptive chemical tests from our previous study using CA instead of Allyl isothiocyanate (AITC) on Girardia dorotocephala (Gd) implementing an open field behavioral analysis. CA induced a dose-dependent increase in scrunching gait similar to the action of AITC and was expectedly partially suppressed by morphine and meloxicam. Knocking down the expression of the Gd-TRPA1 ion channel by RNA interference also suppressed the behavioral reaction to the molecule. In conclusion, we demonstrated that CA induced a nociceptive behavior in planarians through an action on the ion channel TRPA1. SIGNIFICANCE STATEMENT: In this article, we provide evidence that cinnamaldehyde induces a nociceptive behavior through a direct action in an invertebrate model (flatworm) much in the same way that in vertebrates.

Lactate dehydrogenase a-like 6B is not essential for spermatogenesis and male fertility in mice.

Lactate is recognized as a principal energy substrate for male germ cells. Lactate dehydrogenases (LDHs) catalyze the reversible conversion between pyruvate and lactate, which are required for male fertility. Among them, lactate dehydrogenase A-like 6B (Ldhal6b) has been identified as a testis-specific LDH gene. However, its precise roles in spermatogenesis remain to be elucidated. In this study, we used a Ldhal6b knockout mouse model to assess its impact on spermatogenesis. Our findings reveal that Ldhal6b knockout mice exhibit normal development and no significant alterations in male fertility. Further, LDHAL6B is localized to mitochondria and closely associated with germ granules. Nevertheless, its depletion does not result in significant abnormalities in mitochondria, germ granules or impact piRNA biogenesis. We also observed alterations in the abundance of proteins related to mitochondrial metabolism in sperm from Ldhal6b knockout mice, align with its specific localization to mitochondria. Overall, our results indicate that Ldhal6b is dispensable for both mouse development and spermatogenesis under normal laboratory conditions.

Numerical simulation of three-dimensional seepage field in a tailing pond under multiple operating conditions.

Establishing strong seepage stability for tailings dams is crucial for ensuring their safety and mitigating the risk of failure. This study developed a three-dimensional seepage numerical model using finite element numerical computation for four different elevation conditions (5070m, 5081m, 5159m, and 5213m) encompassing the pond area and dam body. Seepage calculations were conducted under normal and flooding conditions, and the tailings pond's seepage stability was assessed for various stacking scenarios. The spatial distribution pattern of the infiltration surface and the hydraulic stability of the tailings pond were evaluated, which provides insights into the three-dimensional infiltration stability. Examining the seepage stability under different accumulation conditions revealed distinct spatial distribution patterns of the infiltration surface and hydraulic ratio drop values. The findings indicated that the maximum permeability slope at 5070m elevation ranged from 0.66 to 0.75 at normal operation water level and maximum flood level. Most hydraulic ratio drop values at 5081m were below 0.2, while the anti-seepage lining sections at 5159m and 5213m showed larger values, and maintained the overall hydraulic ratio drop within safe limits. Consequently, the dam body's permeability was deemed secure, and no infiltration damage was anticipated with the proposed design of seepage control and drainage facilities. Moreover, sensitivity analysis of the tailing sand's permeability coefficient demonstrated that variations between 0.2 and 5 times the given parameter align with the seepage control requirements for the tailings dam. Additionally, local geomembrane breakage was found to have minimal impact on the tailing pond's seepage field and the dam body's permeability stability, which provides a scientific foundation for analyzing and designing the seismic static-dynamic stability of the tailings pond.

Bearing capacity of eco-friendly RC short piles exposed to groundwater salts

AbstractTwenty-eight piles were divided into four groups. Two groups were made of natural aggregate, while the other two were made of full replacement of recycled aggregate. In each group, the cement was replaced with 0, 5, 10, 15, 20, 25 and 30% of silica fume. Two groups were stored for 270 days under normal water conditions, while the other two were stored underground water conditions. Tests results have shown that it’s possible to improve the strength and the structural behavior of piles under sulfate attack considerably by using 20% of silica fume, while 15% is sufficient when the piles are under normal conditions. However, high levels of silica fume 25–30% in recycled aggregate concretes piles and 20–30% in normal aggregate concretes piles gave a clear decrease in ultimate load capacity.