苔藓植物蓝光/紫外光-A 信号传导的研究

种子植物含有5个已分离的光受体和至少1个未鉴定的蓝光/紫外光-A受体。隐花色素(CRY1、CRY2和CRY3) 调节植物的生长发育,而向光蛋白(PHOT1和PHOT2) 调节植物对光的营养反应。黄素可以吸收蓝光和紫外光-A,是生色团。对这些光受体的结构和作用模式已了解很多。苔藓植物小立碗藓中含有2个已分离的隐花色素(CRY1a和CRY1b),负责调节侧枝形成和生长素代谢;有4个向光蛋白(PHOTA1,PHOTA2,PHOTB1,PHOTB2) 调节叶绿体的运动。苔藓细胞内蓝光/紫外光-A刺激引发的信号转导有Ca2+参与。     

The role of phytochrome in stress tolerance

It is well-documented that phytochromes can control plant growth and development from germination to flowering. Additionally, these photoreceptors have been shown to modulate both biotic and abiotic stress. This has led to a series of studies exploring the molecular and biochemical basis by which phytochromes modulate stresses, such as salinity, drought, high light or herbivory. Evidence for a role of phytrochromes in plant stress tolerance is explored and reviewed.     

Individual differences in emotion processing

Recent functional brain imaging studies of the neurobiology of emotion have investigated how individual differences among subjects modulate neural responses during emotion processing. Differences in personality, dispositional affect, biological sex, and genotype can all substantially modulate the neural bases of emotion processing in prefrontal, limbic, and other brain regions, across a variety of domains including emotional reactions, emotional memory, and emotion perception. Analysis of individual differences provides a new window into the neurobiology of emotion processing that complements traditional approaches.     

Economy of mate attraction in the Cassin's finch

Mate attraction can be costly. Thus, individuals should modulate it according to its probable benefits. Specifically, individuals should modulate mate-attraction efforts based on their need for, the probability of attracting, and the reproductive competence of prospective mates. We tested these predictions by monitoring song output in laboratory-housed male Cassin's finches (Carpodacus cassinii) before, during and after brief female exposure following variable periods of isolation from females. We inferred individual reproductive competence from the product of season and reproductive schedule, the latter estimated from moult progress. Males produced little song in the presence of a female but robustly elevated song output in response to female loss. However, mere absence of a female did not elevate song output in males unaccustomed to female proximity. Furthermore, song output in response to female loss increased with her reproductive competence. We suggest that individuals modulate mate-attraction effort based on the benefits such efforts are likely to yield.     

Role of membrane lipid fatty acids in cold adaptation.

Psychrophilic and psychrotolerant bacteria have evolved various strategies to adapt to low temperature. One important strategy, which is crucial to the survival of the cell at low temperature, relates to the ability of the cell to modulate the fluidity of the membrane. Bacteria in general modulate membrane fluidity by altering their fatty acid composition. But, bacteria could also achieve the same by various other strategies such as by altering the lipid head group, the protein content of the membrane, the type of carotenoids synthesized, the fatty acid chain length and the proportion of cis to trans fatty acids. In addition bacteria have a two-component signal transduction pathway consisting of a membrane-bound sensor and a soluble cytoplasmic response regulator involved in the perception and transduction of low temperature signals. This review on cold adaptation highlights the various strategies by which bacteria modulate the fluidity of the membrane and the process by which it senses and transduces the low temperature signal.     

Increased retinoid signaling in vascular smooth muscle cells by proinflammatory cytokines

Retinoids have been shown to modulate inflammation and the immune response in many cell types including macrophages, endothelial cells, and vascular smooth muscle cells. However, present knowledge of whether inflammatory mediators modulate vitamin A status in these cells is limited. To identify the role of inflammation on retinoid metabolism in vascular smooth muscle cells, the cells were exposed to a combination of proinflammatory cytokines: interleukin-1beta, interferon-gamma, and lipopolysaccharides. Without stimulation with proinflammatory cytokines, vascular smooth muscle cells expressed retinol dehydrogenases-2 and 5 mRNA detected by RT-PCR. Stimulation with the combination of cytokines induced a substantial increase of retinol dehydrogenase-5 mRNA. This was associated with increased production of ligands for retinoic acid receptors, when assayed in a retinoic acid receptor-dependent luciferase reporter system. Our results demonstrate that inflammatory mediators activate the retinoid metabolic pathway in vascular smooth muscle cells, which potentially may modulate the inflammatory response in the vascular wall.     

Emerging issues: nutritional awareness in environmental toxicology

Based on recent evidence, we hypothesize that nutrition can modulate the toxicity of environmental pollutants and thus modulate health and disease outcome associated with chemical insults. For example, certain dietary fats may increase the risk to environmental insult induced by polychlorinated biphenyls (PCBs), and fruits and vegetables, rich in antioxidant and anti-inflammatory nutrients or bioactive compounds, may provide protection. Nutritional awareness in environmental toxicology is critical, because of opportunities to develop dietary guidelines which specifically target exposed populations. Nutrition may provide the most sensible means to develop primary prevention strategies of diseases associated with environmental toxicology.     

The reward value of infant facial cuteness tracks within-subject changes in women's salivary testosterone

“Baby schema” refers to infant characteristics, such as facial cues, that positively influence cuteness perceptions and trigger caregiving and protective behaviors in adults. Current models of hormonal regulation of parenting behaviors address how hormones may modulate protective behaviors and nurturance, but not how hormones may modulate responses to infant cuteness. To explore this issue, we investigated possible relationships between the reward value of infant facial cuteness and within-woman changes in testosterone, estradiol, and progesterone levels. Multilevel modeling of these data showed that infant cuteness was more rewarding when women's salivary testosterone levels were high. Moreover, this within-woman effect of testosterone was independent of the possible effects of estradiol and progesterone and was not simply a consequence of changes in women's cuteness perceptions. These results suggest that testosterone may modulate differential responses to infant facial cuteness, potentially revealing a new route through which testosterone shapes selective allocation of parental resources.     

Does Huntingtin play a role in selective macroautophagy?

The accumulation of protein aggregates in neurons appears to be a basic feature of neurodegenerative disease. In Huntington's Disease, a progressive and ultimately fatal neurodegenerative disorder caused by an expansion of the polyglutamine repeat within the protein Huntingtin (Htt), the immediate proximal cause of disease is well understood. However, the cellular mechanisms which modulate the rate at which fragments of Htt containing polyglutamine accumulate in neurons is a central issue in the development of approaches to modulate the rate and extent of neuronal loss in this disease.     

Coexpressed D1- and D2-like dopamine receptors antagonistically modulate acetylcholine release in Caenorhabditis elegans

Dopamine acts through two classes of G protein-coupled receptor (D1-like and D2-like) to modulate neuron activity in the brain. While subtypes of D1- and D2-like receptors are coexpressed in many neurons of the mammalian brain, it is unclear how signaling by these coexpressed receptors interacts to modulate the activity of the neuron in which they are expressed. D1- and D2-like dopamine receptors are also coexpressed in the cholinergic ventral-cord motor neurons of Caenorhabditis elegans. To begin to understand how coexpressed dopamine receptors interact to modulate neuron activity, we performed a genetic screen in C. elegans and isolated mutants defective in dopamine response. These mutants were also defective in behaviors mediated by endogenous dopamine signaling, including basal slowing and swimming-induced paralysis. We used transgene rescue experiments to show that defects in these dopamine-specific behaviors were caused by abnormal signaling in the cholinergic motor neurons. To investigate the interaction between the D1- and D2-like receptors specifically in these cholinergic motor neurons, we measured the sensitivity of dopamine-signaling mutants and transgenic animals to the acetylcholinesterase inhibitor aldicarb. We found that D2 signaling inhibited acetylcholine release from the cholinergic motor neurons while D1 signaling stimulated release from these same cells. Thus, coexpressed D1- and D2-like dopamine receptors act antagonistically in vivo to modulate acetylcholine release from the cholinergic motor neurons of C. elegans.     

Regulation of stress granules in virus systems

Virus infection initiates a number of cellular stress responses that modulate gene regulation and compartmentalization of RNA. Viruses must control host gene expression and the localization of viral RNAs to be successful parasites. RNA granules such as stress granules and processing bodies (PBs) contain translationally silenced messenger ribonucleoproteins (mRNPs) and serve as extensions of translation regulation in cells, storing transiently repressed mRNAs. New reports show a growing number of virus families modulate RNA granule function to maximize replication efficiency. This review summarizes recent advances in understanding the relationship between viruses and mRNA stress granules in animal cells and will discuss important questions that remain in this emerging field.     

Molecular combination networks in medicinal plants: understanding synergy by network pharmacology in Indian traditional medicine

Phytochemistry Reviews - Translation of traditional medicine is moving away from the reductionist approach towards harnessing the synergy of poly-pharmacological phyto-combinations that modulate...     

GABAergic interneuron to astrocyte signalling: a neglected form of cell communication in the brain

GABAergic interneurons represent a minority of all cortical neurons and yet they efficiently control neural network activities in all brain areas. In parallel, glial cell astrocytes exert a broad control of brain tissue homeostasis and metabolism, modulate synaptic transmission and contribute to brain information processing in a dynamic interaction with neurons that is finely regulated in time and space. As most studies have focused on glutamatergic neurons and excitatory transmission, our knowledge of functional interactions between GABAergic interneurons and astrocytes is largely defective. Here, we critically discuss the currently available literature that hints at a potential relevance of this specific signalling in brain function. Astrocytes can respond to GABA through different mechanisms that include GABA receptors and transporters. GABA-activated astrocytes can, in turn, modulate local neuronal activity by releasing gliotransmitters including glutamate and ATP. In addition, astrocyte activation by different signals can modulate GABAergic neurotransmission. Full clarification of the reciprocal signalling between different GABAergic interneurons and astrocytes will improve our understanding of brain network complexity and has the potential to unveil novel therapeutic strategies for brain disorders.     

Dietary flavonoids: Role of (-)-epicatechin and related procyanidins in cell signaling

Plant polyphenols are among the most abundant phytochemicals present in human diets. Increasing evidence supports the health-promoting effects of certain polyphenols, including flavonoids. This review discusses current knowledge of the capacity of monomeric flavanols, i.e., (−)-epicatechin and (+)-catechin, and their derived procyanidins to modulate cell signaling and the associations of these actions with better health. Flavanols and procyanidins can regulate cell signaling through different mechanisms of action. Monomers and dimeric procyanidins can be transported inside cells and directly interact and modulate the activity of signaling proteins and/or prevent oxidation. Larger and nonabsorbable procyanidins can regulate cell signaling by interacting with cell membrane proteins and lipids, inducing changes in membrane biophysics, and by modulating oxidant production. All these actions would be limited by the bioavailability of flavanols at the target tissue. The protection from cardiac and vascular disease and from cancer that is associated with a high consumption of fruit and vegetables could be in part explained by the capacity of flavanols and related procyanidins to modulate proinflammatory and oncogenic signals.