scholarly journals The Imaging of Guard Cells of thioglucosidase (tgg) Mutants of Arabidopsis Further Links Plant Chemical Defence Systems with Physical Defence Barriers

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 227
Author(s):  
Ishita Ahuja ◽  
Ralph Kissen ◽  
Linh Hoang ◽  
Bjørnar Sporsheim ◽  
Kari K. Halle ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Imaging Techniques ◽  
Chemical Defence ◽  
Guard Cells ◽  
Physical Structure ◽  
Distinctive Features ◽  
Defence System ◽  
Plant Chemical ◽  
Novel Association ◽  
Physical Defence

The glucosinolate-myrosinase system is a well-known plant chemical defence system. Two functional myrosinase-encoding genes, THIOGLUCOSIDASE 1 (TGG1) and THIOGLUCOSIDASE 2 (TGG2), express in aerial tissues of Arabidopsis. TGG1 expresses in guard cells (GCs) and is also a highly abundant protein in GCs. Recently, by studying wild type (WT), tgg single, and double mutants, we showed a novel association between the glucosinolate-myrosinase system defence system, and a physical barrier, the cuticle. In the current study, using imaging techniques, we further analysed stomata and ultrastructure of GCs of WT, tgg1, tgg2 single, and tgg1 tgg2 double mutants. The tgg mutants showed distinctive features of GCs. The GCs of tgg1 and tgg1 tgg2 mutants showed vacuoles that had less electron-dense granular material. Both tgg single mutants had bigger stomata complexes. The WT and tgg mutants also showed variations for cell wall, chloroplasts, and starch grains of GCs. Abscisic acid (ABA)-treated stomata showed that the stomatal aperture was reduced in tgg1 single and tgg1 tgg2 double mutants. The data provides a basis to perform comprehensive further studies to find physiological and molecular mechanisms associated with ultrastructure differences in tgg mutants. We speculate that the absence of myrosinase alters the endogenous chemical composition, hence affecting the physical structure of plants and the plants’ physical defence barriers.

scholarly journals Degenerative Cervical Myelopathy: Insights into Its Pathobiology and Molecular Mechanisms

2021 ◽  
Vol 10 (6) ◽  
pp. 1214
Author(s):  
Ji Tu ◽  
Jose Vargas Castillo ◽  
Abhirup Das ◽  
Ashish D. Diwan
Keyword(s):  
Cervical Myelopathy ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Imaging Techniques ◽  
Disease Process ◽  
Classification Systems ◽  
Molecular Features ◽  
Formidable Challenge ◽  
Long Term Treatment ◽  
Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairment of motor function in the arms, fingers and hands. If left untreated, this can lead to significant and permanent nerve damage including paralysis and death. Despite recent advancements in understanding the DCM pathology, prognosis remains poor and little is known about the molecular mechanisms underlying its pathogenesis. Moreover, there is scant evidence for the best treatment suitable for DCM patients. Decompressive surgery remains the most effective long-term treatment for this pathology, although the decision of when to perform such a procedure remains challenging. Given the fact that the aged population in the world is continuously increasing, DCM is posing a formidable challenge that needs urgent attention. Here, in this comprehensive review, we discuss the current knowledge of DCM pathology, including epidemiology, diagnosis, natural history, pathophysiology, risk factors, molecular features and treatment options. In addition to describing different scoring and classification systems used by clinicians in diagnosing DCM, we also highlight how advanced imaging techniques are being used to study the disease process. Last but not the least, we discuss several molecular underpinnings of DCM aetiology, including the cells involved and the pathways and molecules that are hallmarks of this disease.

scholarly journals Imaging and Molecular Mechanisms of Alzheimer’s Disease: A Review

2018 ◽  
Vol 19 (12) ◽  
pp. 3702 ◽  
Author(s):  
Grazia Femminella ◽  
Tony Thayanandan ◽  
Valeria Calsolaro ◽  
Klara Komici ◽  
Giuseppe Rengo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Multimodal Imaging ◽  
Molecular Mechanisms ◽  
Imaging Techniques ◽  
Structural Mri ◽  
Imaging Biomarkers ◽  
Significant Burden ◽  
Made In

Alzheimer’s disease is the most common form of dementia and is a significant burden for affected patients, carers, and health systems. Great advances have been made in understanding its pathophysiology, to a point that we are moving from a purely clinical diagnosis to a biological one based on the use of biomarkers. Among those, imaging biomarkers are invaluable in Alzheimer’s, as they provide an in vivo window to the pathological processes occurring in Alzheimer’s brain. While some imaging techniques are still under evaluation in the research setting, some have reached widespread clinical use. In this review, we provide an overview of the most commonly used imaging biomarkers in Alzheimer’s disease, from molecular PET imaging to structural MRI, emphasising the concept that multimodal imaging would likely prove to be the optimal tool in the future of Alzheimer’s research and clinical practice.

scholarly journals Surface chemistry and morphology in single particle optical imaging

Nanophotonics ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 713-730 ◽  
Author(s):  
Fulya Ekiz-Kanik ◽  
Derin Deniz Sevenler ◽  
Neşe Lortlar Ünlü ◽  
Marcella Chiari ◽  
M. Selim Ünlü
Keyword(s):  
Optical Imaging ◽  
Imaging Techniques ◽  
High Specificity ◽  
Physical Structure ◽  
Dark Field ◽  
Imaging Systems ◽  
Label Free ◽  
Inhomogeneous Surface ◽  
Improve Measurement ◽  
Molecular Specificity

AbstractBiological nanoparticles such as viruses and exosomes are important biomarkers for a range of medical conditions, from infectious diseases to cancer. Biological sensors that detect whole viruses and exosomes with high specificity, yet without additional labeling, are promising because they reduce the complexity of sample preparation and may improve measurement quality by retaining information about nanoscale physical structure of the bio-nanoparticle (BNP). Towards this end, a variety of BNP biosensor technologies have been developed, several of which are capable of enumerating the precise number of detected viruses or exosomes and analyzing physical properties of each individual particle. Optical imaging techniques are promising candidates among broad range of label-free nanoparticle detectors. These imaging BNP sensors detect the binding of single nanoparticles on a flat surface functionalized with a specific capture molecule or an array of multiplexed capture probes. The functionalization step confers all molecular specificity for the sensor’s target but can introduce an unforeseen problem; a rough and inhomogeneous surface coating can be a source of noise, as these sensors detect small local changes in optical refractive index. In this paper, we review several optical technologies for label-free BNP detectors with a focus on imaging systems. We compare the surface-imaging methods including dark-field, surface plasmon resonance imaging and interference reflectance imaging. We discuss the importance of ensuring consistently uniform and smooth surface coatings of capture molecules for these types of biosensors and finally summarize several methods that have been developed towards addressing this challenge.

Constitutive and inducible Saccharomyces cerevisiae promoters: evidence for two distinct molecular mechanisms

1986 ◽  
Vol 6 (11) ◽  
pp. 3847-3853
Author(s):  
K Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Mechanisms ◽  
Normal Growth ◽  
Regulatory Elements ◽  
Growth Conditions ◽  
Physical Structure ◽  
Base Pairs ◽  
Inducible Promoters ◽  
Upstream Promoter ◽  
Selection Of

his3 and pet56 are adjacent Saccharomyces cerevisiae genes that are transcribed in opposite directions from initiation sites that are separated by 200 base pairs. Under normal growth conditions, in which his3 and pet56 are transcribed at similar basal levels, a poly(dA-dT) sequence located between the genes serves as the upstream promoter element for both. In contrast, his3 but not pet56 transcription is induced during conditions of amino acid starvation, even though the critical regulatory site is located upstream of both respective TATA regions. Moreover, only one of the two normal his3 initiation sites is subject to induction. From genetic and biochemical evidence, I suggest that the his3-pet56 intergenic region contains constitutive and inducible promoters with different properties. In particular, two classes of TATA elements, constitutive (Tc) and regulatory (Tr), can be distinguished by their ability to respond to upstream regulatory elements, by their effects on the selection of initiation sites, and by their physical structure in nuclear chromatin. Constitutive and inducible his3 transcription is mediated by distinct promoters representing each class, whereas pet56 transcription is mediated by a constitutive promoter. Molecular mechanisms for these different kinds of S. cerevisiae promoters are proposed.

scholarly journals Molecular and Imaging Biomarkers in Alzheimer’s Disease: A Focus on Recent Insights

2020 ◽  
Vol 10 (3) ◽  
pp. 61 ◽  
Author(s):  
Chiara Villa ◽  
Marialuisa Lavitrano ◽  
Elena Salvatore ◽  
Romina Combi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mechanisms ◽  
Biological Fluids ◽  
Imaging Techniques ◽  
Amyloid Β ◽  
The Elderly ◽  
Diagnostic Methods ◽  
Imaging Biomarkers ◽  
Attractive Alternative

Alzheimer’s disease (AD) is the most common neurodegenerative disease among the elderly, affecting millions of people worldwide and clinically characterized by a progressive and irreversible cognitive decline. The rapid increase in the incidence of AD highlights the need for an easy, efficient and accurate diagnosis of the disease in its initial stages in order to halt or delay the progression. The currently used diagnostic methods rely on measures of amyloid-β (Aβ), phosphorylated (p-tau) and total tau (t-tau) protein levels in the cerebrospinal fluid (CSF) aided by advanced neuroimaging techniques like positron emission tomography (PET) and magnetic resonance imaging (MRI). However, the invasiveness of these procedures and the high cost restrict their utilization. Hence, biomarkers from biological fluids obtained using non-invasive methods and novel neuroimaging approaches provide an attractive alternative for the early diagnosis of AD. Such biomarkers may also be helpful for better understanding of the molecular mechanisms underlying the disease, allowing differential diagnosis or at least prolonging the pre-symptomatic stage in patients suffering from AD. Herein, we discuss the advantages and limits of the conventional biomarkers as well as recent promising candidates from alternative body fluids and new imaging techniques.

scholarly journals Differentiation of Tracheary Elements in Sugarcane Suspension Cells Involves Changes in Secondary Wall Deposition and Extensive Transcriptional Reprogramming

2020 ◽  
Vol 11 ◽  
Author(s):  
Marcella Siqueira Simões ◽  
Sávio Siqueira Ferreira ◽  
Adriana Grandis ◽  
Jorge Rencoret ◽  
Staffan Persson ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Plant Biomass ◽  
Physical Structure ◽  
Grass Species ◽  
Phenylpropanoid Metabolism ◽  
Primary Metabolism ◽  
Tracheary Elements ◽  
Suspension Cells ◽  
Transcriptional Reprogramming

Plant lignocellulosic biomass, mostly composed of polysaccharide-rich secondary cell walls (SCWs), provides fermentable sugars that may be used to produce biofuels and biomaterials. However, the complex chemical composition and physical structure of SCWs hinder efficient processing of plant biomass. Understanding the molecular mechanisms underlying SCW deposition is, thus, essential to optimize bioenergy feedstocks. Here, we establish a xylogenic culture as a model system to study SCW deposition in sugarcane; the first of its kind in a C4 grass species. We used auxin and brassinolide to differentiate sugarcane suspension cells into tracheary elements, which showed metaxylem-like reticulate or pitted SCW patterning. The differentiation led to increased lignin levels, mainly caused by S-lignin units, and a rise in p-coumarate, leading to increased p-coumarate:ferulate ratios. RNAseq analysis revealed massive transcriptional reprogramming during differentiation, with upregulation of genes associated with cell wall biogenesis and phenylpropanoid metabolism and downregulation of genes related to cell division and primary metabolism. To better understand the differentiation process, we constructed regulatory networks of transcription factors and SCW-related genes based on co-expression analyses. Accordingly, we found multiple regulatory modules that may underpin SCW deposition in sugarcane. Our results provide important insights and resources to identify biotechnological strategies for sugarcane biomass optimization.

How insects overcome two-component plant chemical defence: plantβ-glucosidases as the main target for herbivore adaptation

2013 ◽  
Vol 89 (3) ◽  
pp. 531-551 ◽  
Author(s):  
Stefan Pentzold ◽  
Mika Zagrobelny ◽  
Fred Rook ◽  
Søren Bak
Keyword(s):  
Chemical Defence ◽  
Plant Chemical ◽  
Two Component ◽  
Main Target

scholarly journals Sugar Beet (Beta vulgaris) Guard Cells Responses to Salinity Stress: A Proteomic Analysis

2020 ◽  
Vol 21 (7) ◽  
pp. 2331
Author(s):  
Fatemeh Rasouli ◽  
Ali Kiani-Pouya ◽  
Leiting Li ◽  
Heng Zhang ◽  
Zhonghua Chen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sugar Beet ◽  
Molecular Mechanisms ◽  
Stress Proteins ◽  
Lipid Transfer Protein ◽  
Guard Cells ◽  
Ascorbate Oxidase ◽  
Carbon Gain ◽  
Inorganic Pyrophosphatase ◽  
Cell Wall Modification

Soil salinity is a major environmental constraint affecting crop growth and threatening global food security. Plants adapt to salinity by optimizing the performance of stomata. Stomata are formed by two guard cells (GCs) that are morphologically and functionally distinct from the other leaf cells. These microscopic sphincters inserted into the wax-covered epidermis of the shoot balance CO2 intake for photosynthetic carbon gain and concomitant water loss. In order to better understand the molecular mechanisms underlying stomatal function under saline conditions, we used proteomics approach to study isolated GCs from the salt-tolerant sugar beet species. Of the 2088 proteins identified in sugar beet GCs, 82 were differentially regulated by salt treatment. According to bioinformatics analysis (GO enrichment analysis and protein classification), these proteins were involved in lipid metabolism, cell wall modification, ATP biosynthesis, and signaling. Among the significant differentially abundant proteins, several proteins classified as “stress proteins” were upregulated, including non-specific lipid transfer protein, chaperone proteins, heat shock proteins, inorganic pyrophosphatase 2, responsible for energized vacuole membrane for ion transportation. Moreover, several antioxidant enzymes (peroxide, superoxidase dismutase) were highly upregulated. Furthermore, cell wall proteins detected in GCs provided some evidence that GC walls were more flexible in response to salt stress. Proteins such as L-ascorbate oxidase that were constitutively high under both control and high salinity conditions may contribute to the ability of sugar beet GCs to adapt to salinity by mitigating salinity-induced oxidative stress.

scholarly journals An Unusual ERAD-Like Complex Is Targeted to the Apicoplast of Plasmodium falciparum

2009 ◽  
Vol 8 (8) ◽  
pp. 1134-1145 ◽  
Author(s):  
Simone Spork ◽  
Jan A. Hiss ◽  
Katharina Mandel ◽  
Maik Sommer ◽  
Taco W. A. Kooij ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Mechanisms ◽  
Protein Transport ◽  
Fluorescent Protein ◽  
Imaging Techniques ◽  
Encoded Proteins ◽  
Red Algal ◽  
Endosymbiotic Event ◽  
Targeting Signal ◽  
Green Fluorescent

ABSTRACT Many apicomplexan parasites, including Plasmodium falciparum, harbor a so-called apicoplast, a complex plastid of red algal origin which was gained by a secondary endosymbiotic event. The exact molecular mechanisms directing the transport of nuclear-encoded proteins to the apicoplast of P. falciparum are not well understood. Recently, in silico analyses revealed a second copy of proteins homologous to components of the endoplasmic reticulum (ER)-associated protein degradation (ERAD) system in organisms with secondary plastids, including the malaria parasite P. falciparum. These proteins are predicted to be endowed with an apicoplast targeting signal and are suggested to play a role in the transport of nuclear-encoded proteins to the apicoplast. Here, we have studied components of this ERAD-derived putative preprotein translocon complex in malaria parasites. Using transfection technology coupled with fluorescence imaging techniques we can demonstrate that the N terminus of several ERAD-derived components targets green fluorescent protein to the apicoplast. Furthermore, we confirm that full-length PfsDer1-1 and PfsUba1 (homologues of yeast ERAD components) localize to the apicoplast, where PfsDer1-1 tightly associates with membranes. Conversely, PfhDer1-1 (a host-specific copy of the Der1-1 protein) localizes to the ER. Our data suggest that ERAD components have been “rewired” to provide a conduit for protein transport to the apicoplast. Our results are discussed in relation to the nature of the apicoplast protein transport machinery.

scholarly journals How I treat extramedullary myeloma

Blood ◽  
2016 ◽  
Vol 127 (8) ◽  
pp. 971-976 ◽  
Author(s):  
Cyrille Touzeau ◽  
Philippe Moreau
Keyword(s):  
Bone Marrow ◽  
High Risk ◽  
Median Overall Survival ◽  
Molecular Mechanisms ◽  
Plasma Cells ◽  
Imaging Techniques ◽  
Lactate Dehydrogenase Level ◽  
Altered Expression ◽  
Positron Emission ◽  
Extramedullary Relapse

Abstract Extramedullary myeloma (EMM) is defined by the presence of plasma cells (PCs) outside the bone marrow in a patient with multiple myeloma (MM). Using sensitive imaging techniques including magnetic resonance imaging and positron emission tomography/computed tomography, EMM may be found in up to 30% of MM patients across the overall disease course. The molecular mechanisms underlying the hematogenous spread of PCs outside the bone marrow are only partially known and involve hypoxia and an altered expression of adhesion molecules. Extramedullary disease is associated with adverse prognostic factors (ie, high lactate dehydrogenase level, 17p deletion, and high-risk gene expression profile). The prognosis of EMM is poor, and the median overall survival of patients who experience an extramedullary relapse is <6 months. The adverse prognosis is less pronounced in patients with bone-related plasmacytomas than in those with hematogenous EMM. EMM patients should be considered as having high-risk myeloma and treated accordingly. However, EMM clinical situations are extraordinarily heterogeneous, and their management is particularly challenging. In the present review, a case-and-comment format is used to describe our approach to the management of EMM.

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