Multiple Response Patterns Research Articles

Identification of the DcHsp20 gene family in carnation (Dianthus caryophyllus) and functional characterization of DcHsp17.8 in heat tolerance.

33 heat shock protein 20 (Hsp20) genes were identified from the carnation genome whose expression were altered by abiotic stresses. DcHsp17.8 may function to improve the heat resistance of Arabidopsis. Heat shock proteins 20 (Hsp20s) mainly function as molecular chaperones that play crucial roles in relieving abiotic stresses such as heat stress. In this study, we identified and characterized 33 DcHsp20 genes from the carnation genome that were classified into 9 subfamilies. Gene structure analysis showed that 25 DcHsp20 genes contained 1 intron whilst the remaining 8 DcHsp20 genes did not contain introns. Motif analysis found that DcHsp20 proteins were relatively conserved. Cis-regulatory elements analysis of the Hsp20 promoters revealed a number of cis-regulatory elements that regulate growth and development, hormone and stress responses. Gene expression analysis revealed that DcHsp20 genes had multiple response patterns to heat stress. The largest range of induction occurred in DcHsp17.8 after 1h of heat stress. Under cold stress, or treatment with saline or abscisic acid, the expression of most DcHsp20 genes was inhibited. To further understand the function of DcHsp20 genes in response to heat stress, we overexpressed DcHsp17.8 in Arabidopis and the plants showed improved heat tolerance, O2- and H2O2 activities and photosynthetic capacity with reduced relative electrolyte leakage and malondialdehyde content. Gene expression analysis revealed that DcHsp17.8 modulated the expression of genes involved in antioxidant enzyme synthesis. Our data provided a solid foundation for the further detailed study of DcHsp20 genes.

Regulating the wetting behaviors of hollow silica photonic crystals in detection and encryption applications

Regulating the wettability of photonic crystals (PCs) could manipulate the liquid flow, and thus, multiple response patterns were realized for information storage and sensing devices. In this paper, to realize solvent detection by response patterns with shapes and colors difference, several modified agents were introduced into hollow silica photonic crystals (HSPCs), obtaining the array sensors. The as-prepared array sensors exhibited superior sensitivity and wide detection range for organic solvents, which showed six response patterns in response to different organic solvents wiping due to surface tensions and reflective index difference of solvents. The array sensors could verify cyclohexane and N-hexane by their surface tensions differences, and verify the diiodomethane by reflective index difference with an 83 nm of reflection wavelength shift. Furthermore, information encryption and multilevel decryption were realized on modified HSPCs, different encrypted patterns and words would be revealed by ethanol solutions (5% and 15% concentration) wiping. Overall, based on the above-mentioned properties, this strategy by regulating wetting behaviours of HSPCs would pave a new route for self-reporting sensors fabrication and complex information encryption.

Bionic intelligent soft actuators: high-strength gradient intelligent hydrogels with diverse controllable deformations and movements.

A series of novel nanofibrillated cellulose (NFC) reinforced gradient intelligent hydrogels with high response rate, multiple response patterns and diversified self-driven functions were successfully prepared. Based on the effect of the hydroxide radical of NFC on the addition reaction, and on the dehydration synthesis, the variation of NFC significantly regulated the gradient structure of the intelligent hydrogels. In addition to the infiltration property of graphene oxide (GO), reinforcement of NFC enhanced the crosslinking density and Young's modulus, which built a relationship between material characteristics and near infrared laser response rate. Intelligent hydrogel actuators realized bending deformation, curling deformation, switching movements and obstacle avoidance movements. The hydrogels with high Young's modulus exhibited relatively low self-driven rates and efficiency. The self-driven mechanisms of NFC reinforced gradient intelligent hydrogels were revealed effectively by constructing the mathematical relationship curvature variation, bending degree, deformation displacement, material characteristics and incentive intensity. The investigation showed a new path for the combination of mechanical property, intelligent property and functional property of intelligent hydrogels in a bionic soft robot and health engineering.

Dynamics and diversity of heart rate responses to a disaster motion picture

Emotions are dynamic neuropsychophysiological processes that guide behavior and serve as crucial signals during social interactions. Measuring their highly individual temporal dynamics is an unresolved challenge, but the coupling of autonomic and central nervous processes offers a promising approach. We present a feasible approach to study changes in heart rate during emotions and demonstrate a link to empathy.We investigated the interindividual similarity and temporal dynamics of heart rate responses to an emotive motion picture. Forty healthy participants watched “The Impossible” (109 min; Hermida Muñiz et al., 2012) while their heart rate was recorded. Interindividual concordance of heart rate responses was analysed using agglomerative hierarchical clustering analyses to distinguish response patterns throughout the movie and during six highly emotive scenes. This revealed multiple response patterns during emotive scenes. Second, we analysed how changes in heart rate are linked to self-reported empathy. We found that the extent of changes in heart rate is positively linked to trait and state empathy. During specific scenes, this relationship was only visible when individuals with homogeneous heart rate response patterns were observed, but not across discordant response patterns.In conclusion, our results demonstrate that heart rate responses to complex social stimuli are not uniform. Therefore, research should favour statistical procedures with the potential to detect interindividual differences. The approach presented in our study allows us to depict interindividual similarity and diversity in emotional autonomic responses and emphasizes the key role of empathy in emotional experiences.

Evidence for deleterious hepatitis C virus quasispecies mutation loads that differentiate the response patterns in IFN-based antiviral therapy.

Viral quasispecies (QS) have long been considered to affect the efficiency of hepatitis C virus (HCV) antiviral therapy, but a correlation between QS diversity and treatment outcomes has not been established conclusively. We previously measured HCV QS diversity by genome-wide quantification of high-resolution mutation load in HCV genotype 1a patients achieving a sustained virological response (1a/SVR) or a null response (1a/null). The current study extended this work into HCV 1a patients experiencing relapse (1a/relapse, n = 19) and genotype 2b patients with SVR (2b/SVR, n = 10). The mean mutation load per patient in 2b/SVR and 1a/relapse was similar, respectively, to 1a/SVR (517.6 ± 174.3 vs 524 ± 278.8 mutations, P = 0.95) and 1a/null (829.2 ± 282.8 vs 805.6 ± 270.7 mutations, P = 0.78). Notably, a deleterious mutation load, as indicated by the percentage of non-synonymous mutations, was highest in 2b/SVR (33.2 ± 8.5%) as compared with 1a/SVR (23.6 ± 7.8%, P = 0.002), 1a/null (18.2 ± 5.1%, P = 1.9 × 10(-7)) or 1a/relapse (17.8 ± 5.3%, P = 1.8) × 10(-6). In the 1a/relapse group, continuous virus evolution was observed with excessive accumulation of a deleterious load (17.8 ± 5.3% vs 35.4 ± 12.9%, P = 3.5 × 10(-6)), supporting the functionality of Muller's ratchet in a treatment-induced population bottleneck. Taken together, the magnitude of HCV mutation load, particularly the deleterious mutation load, provides an evolutionary explanation for the emergence of multiple response patterns as well as an overall high SVR rate in HCV genotype 2 patients. Augmentation of Muller's ratchet represents a potential strategy to reduce or even eliminate viral relapse in HCV antiviral therapy.

Exploiting dependencies of pairwise comparison outcomes to predict patterns of gene response.

BackgroundThe analysis of gene expression has played an important role in medical and bioinformatics research. Although it is known that a large number of samples is needed to determine the patterns of gene expression accurately, practical designs of gene expression studies occasionally have insufficient numbers of samples, making it difficult to ascertain true response patterns of variantly expressed genes.ResultsWe describe an approach to cope with the challenge of predicting true orders of gene response to treatments. We show that true patterns of gene response must be orderable sets. In experiments with few samples, we modify the conventional pairwise comparison tests and increase the significance level α intelligently to deduce orderable patterns, which are most likely true orders of gene response. Additionally, motivated by the fact that a gene can be involved in multiple biological functions, our method further resamples experimental replicates and predicts multiple response patterns for each gene.Using a gene expression data set of Sprague-Dawley rats treated with chemopreventive chemical compounds and DAVID to annotate and validate gene sets, we showed that compared to the conventional method of fixing α, this method increased enrichment significantly. A comparison with hierarchical clustering showed that gene clusters labelled by response patterns produced by our method were much more enriched. One of the clusters contained 3 transcription factors, which hierarchical clustering failed to place into one cluster, that have been found to participate in multiple biological networks. One of the transcription factors is known to play an important role in pathways affected by the studied chemical compounds.ConclusionsThis method can be useful in designing cost-effective experiments with small sample sizes. Patterns of highly-variantly expressed genes can be predicted by varying α intelligently. Furthermore, clusters are labeled meaningfully with patterns that describe precisely how genes in such clusters respond to treatments.

Hemodynamic changes are encoded into distinct astrocyte and neuronal responses highlighting the importance of bidirectional communication at the neurovascular unit

To gain insights into the dynamic signaling events at the neurovascular unit, we evaluated if hemodynamic changes within parenchymal arterioles altered glial and/or neuronal activity in cortical brain slices. We hypothesize that astrocytes monitor brain hemodynamics and that changes in pressure and/or flow are rapidly sensed by these cells and tranduced to neighboring neurons adjusting, in this way, activity to blood flow supply. We used a novel in vitro approach which included pressure/flow changes in parenchymal arterioles while simultaneously measuring Ca2+ activity in perivascular astrocytes and firing activity from pyramidal or cortical interneurons. Our findings show that astrocytes rapidly sense increases in pressure (from 40 to 80 mmHg) resulting in a 124% increased in Ca2+ oscillation frequency. Moreover, an 80% reduction in neuronal firing activity was observed in the presence of the hymodynamic stimulus. A detailed characterization of astrocytic responses revealed the presence of multiple response patterns to the hemodynamic stimulus including: transient activation (21%), tonic/oscillatory activity (26%) and inhibition (52%). The present study support a complex form of vascular‐to‐glial‐to‐neuronal communication in which hemodynamic changes are encoded into distinct astrocyte/neuronal responses.

Using null model analysis of species co‐occurrences to deconstruct biodiversity patterns and select indicator species

AbstractAim Using total species richness to characterize biodiversity may mask multiple response patterns of species. We propose a null model analysis of species co‐occurrence‐based classification to identify sets of species that may have similar (within‐groups) and distinct (between groups) response patterns to their environment. The classification should also provide an explicit framework for selecting indicator species with characteristic co‐occurrence patterns to predict overall species richness.Location Côte‐Nord, Québec, Canada.Methods We combined null‐model of species co‐occurrence and cluster analysis to identify species groups within diverse assemblages of ground‐dwelling and flying beetles of stands in a boreal forest mosaic; we then examined their co‐occurrence and response patterns to habitat characteristics. Best subset regressions were used to select indicator species of richness within each group, from which indicators of total species richness were selected.Results The identified species groups appeared to display contrasting co‐occurrence and response patterns to at least one of the stand‐level habitat characteristics. Among flying beetles, for example, richness increased with stand‐level heterogeneity for two groups and decreased for two other groups, but the relationship was non‐significant for the total richness. We identified 28 indicator species that explained > 80% (validated by bootstrap analysis) of the variation in total species richness. Predictive performance of indicators was higher than when their co‐occurrence were reshuffled, even under a highly constrained null model, indicating that co‐occurrence patterns contributed to their predictive performance.Main conclusions Co‐occurrence‐based classification appears as a promising and effective tool for deconstructing biodiversity into species groups which reflect their ecological commonalities and differences, thus reducing the risk of making faulty inferences about the causes underlying overall diversity patterns. The method provides an explicit framework for selecting indicator species representing different species groups that may reflect the multiple responses of species co‐occurring with them. Indicator species can be effective for predicting overall species richness.

Differential responses of normal human coronary artery endothelial cells against multiple cytokines comparatively assessed by gene expression profiles

Endothelial cells play an important role in terms of biological functions by responding to a variety of stimuli in the blood. However, little is known about the molecular mechanism involved in rendering the variety in the cellular response. To investigate the variety of the cellular responses against exogenous stimuli at the gene expression level, we attempted to describe the cellular responses with comprehensive gene expression profiles, dissect them into multiple response patterns, and characterize the response patterns according to the information accumulated so far on the genes included in the patterns. We comparatively analyzed in parallel the gene expression profiles obtained with DNA microarrays from normal human coronary artery endothelial cells (HCAECs) stimulated with multiple cytokines, interleukin-1β, tumor necrosis factor-α, interferon-β, interferon-γ, and oncostatin M, which are profoundly involved in various functional responses of endothelial cells. These analyses revealed that the cellular responses of HCAECs against these cytokines included at least 15 response patterns specific to a single cytokine or common to multiple cytokines. Moreover, we statistically extracted genes contained within the individual response patterns and characterized the response patterns with the genes referring to the previously accumulated findings including the biological process defined by the Gene Ontology Consortium (GO). Out of the 15 response patterns in which at least one gene was successfully extracted through the statistical approach, 11 response patterns were differentially characterized by representing the number of genes contained in individual criteria of the biological process in the GO only. The approach to dissect cellular responses into response patterns and to characterize the pattern at the gene expression level may contribute to the gaining of insight for untangling the diversity of cellular functions.

Ca2+]i imaging in PC12 cells: multiple response patterns to receptor activation reveal new aspects of transmembrane signaling.

Fura-2 imaging microscopy was used to study [Ca2+]i in nerve growth factor-differentiated PC12 cells exposed to agonists (bradykinin, carbamylcholine, and ATP) binding to receptors coupled to polyphosphoinositide hydrolysis. With all the treatments employed, the response to an individual agonist was often incomplete, i.e., composed of either release from intracellular stores or influx only. In individual cells the responses were closely similar when only one and the same agonist was employed, and markedly heterogeneous, with considerable variation of the release/influx ratio, when different agonists were delivered in sequence. In a recently isolated PC12 cell clone, heterogeneity of the receptor-induced [Ca2+]i responses was markedly lower than in the overall population, although the release/influx ratio was still variable. We conclude that the large response heterogeneity observed in the overall PC12 cell population is due (a) to the coexistence of multiple clones; and (b) to the variable activation of intracellular transduction mechanisms.

Multiple response patterns to oestrogenic stimulation in the avian liver

The response patterns of vitellogenin, very low density lipoprotein-apoprotein B (apo VLDL-B), and serum albumin were examined following oestrogen administration to roosters. Vitellogenin synthesis was not detectable in the absence of hormone treatment, but increased to a maximum within 3–6 days following oestrogen treatment. The hormone-stimulated increase in vitellogenin synthesis was paralleled by the accumulation of vitellogenin mRNA. In contrast to the complete oestrogen-dependence of vitellogenin synthesis, an appreciable level of apo VLDL-B synthesis was seen in the absence of exogenous hormone treatment. Following oestrogen treatment, the hepatic synthesis of apo VLDL-B increased to an extent similar in magnitude to the increase in vitellogenin synthesis. In the case of apo VLDL-B, oestrogen appears to modulate the expression of a gene which is expressed to a significant extent in the absence of the hormone. In contrast to the positive effects of oestrogen on vitellogenin and apo VLDL-B, the hepatic content of serum albumin mRNA was seen to decrease following hormone treatment. Comparison of the response patterns of these proteins suggests that oestrogen may exhibit multiple modes of control over the expression of different genes within the same cell.