Thermoplasmonic Scaffold Design for the Modulation of Neural Activity in Three-Dimensional Neuronal Cultures

Andrea Andolfi,장현수,Sergio Martinoia,남윤기 한국바이오칩학회 2022 BioChip Journal Vol.16 No.4

Neuromodulation has made great strides in recent years, but in vitro studies have been limited to two-dimensional cell cultures, far from in vivo conditions. In this study, we realized a novel thermoplasmonic platform for modulating the neural activity of three-dimensional cell cultures, providing a new tool to bring in vitro neuromodulation studies into a threedimensional environment. The photosensitive scaffold, obtained by covering soda-lime glass microbeads (diameter about 40 μm) with gold nanorods, integrates microbeads’ structural properties, intended to support the development of the neural network in three dimensions, with the photothermal properties of plasmonic nanoparticles. We demonstrate its efficiency in providing support for the construction of three-dimensional cell culture and how, under Near-infrared laser irradiation, their photothermal effect can precisely and non-invasively modulate the activity of the neural network. Our platform is expected to be a useful tool for improving neural network studies to better understand complex brain functions and neural disorders.

Functions of ABC transporters in plant growth and development

Do, Thanh Ha Thi,Martinoia, Enrico,Lee, Youngsook Elsevier 2018 Current opinion in plant biology Vol.41 No.-

<P>ABC transporters are essential for plant development, playing roles in processes such as gametogenesis, seed development, seed germination, organ formation, and secondary growth. ABC transporters are directly energized by ATP and can transport complex organic materials against concentration gradients; thus, they are uniquely suited to provide the complex building blocks required for the development of specialized plant cells. We review recent progress in our understanding of the contribution ABC transporters make to the growth and development of plants, including their roles in protective layer formation and in transporting phytohormones.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ABC transporters are critical for plant growth and development. </LI> <LI> New alleles of known ABC transporters have revealed novel physiological roles. </LI> <LI> Studies of ABC transporters with substrate biosynthesis enzymes were fruitful. </LI> </UL> </P>

Long-distance Transporters of Inorganic Nutrients in Plants

( Ji Young Park ),( Yu Young Kim ),( Enrico Martinoia ),( Young Sook Lee ) 한국식물학회 2008 Journal of Plant Biology Vol.51 No.4

In plants, long-distance transport of inorganic nutrients is important for mineral nutrition, ion homeostasis, nutrient recycling, and the detoxification of toxic or excess inorganic ions. Here, we review information on the transporters involved in the loading/unloading of inorganic nutrients to and from the vascular bundle. We also describe the methods used to obtain such information.

Cytokinin Transporters: GO and STOP in Signaling

Kang, Joohyun,Lee, Youngsook,Sakakibara, Hitoshi,Martinoia, Enrico Elsevier 2017 Trends in plant science Vol.22 No.6

<P>Cytokinins are phytohormones essential for cytokinesis and many other physiological and developmental processes <I>in planta</I>. Long-distance transport and intercellular transport have been postulated. For these processes, the existence of cytokinin transporters has been suggested. Recently, a transporter loading the xylem (AtABCG14) and another for cellular import (AtPUP14) have been discovered. AtABCG14 participates in the xylem loading process of cytokinins and contributes to the positive regulation of shoot growth. The cellular importer AtPUP14 is required to suppress cytokinin signaling. A role of a transporter as stop signal is a new paradigm for a hormone transporter.</P> <P><B>Trends</B></P> <P>Recently, two types of cytokinins transporters have been identified and shown to play key roles in plant development and many important physiology processes.</P> <P>ABCG14 contributes to the ‘GO’ signal regulating shoot growth by delivering cytokinins via the xylem. By contrast, the cytokinin uptake transporter PUP14 is in charge of ‘stopping’ the signal at the top of intracellular cytokinin signaling, by removing the ligand that activates the receptors.</P>

The ABC transporter AtPDR8 is a cadmium extrusion pump conferring heavy metal resistance

Kim, Do-Young,Bovet, Lucien,Maeshima, Masayoshi,Martinoia, Enrico,Lee, Youngsook Blackwell Publishing Ltd 2007 The Plant journal Vol.50 No.2

<P>Summary</P><P>Cadmium (Cd) and lead (Pb) are widespread pollutants that are toxic to plant growth. The expression of <I>AtPDR8</I> was upregulated in cadmium- or lead-treated <I>Arabidopsis thaliana.</I> To test whether AtPDR8 is involved in heavy metal resistance, we examined transgenic Arabidopsis that over-expressed AtPDR8 and RNAi plants that exhibited a severely reduced <I>AtPDR8</I> transcript level, as well as T-DNA insertion mutants of this ABC transporter. AtPDR8-over-expressing plants were more resistant to Cd<SUP>2+</SUP> or Pb<SUP>2+</SUP> than the wild-type and had lower Cd contents. In contrast, AtPDR8 RNAi transgenic plants and T-DNA insertion lines were more sensitive to Cd<SUP>2+</SUP> or Pb<SUP>2+</SUP> compared to wild-type plants and had higher Cd contents. The GFP–AtPDR8 protein was targeted to the plasma membrane, and GUS activity was present in most cells but strongest in the root hair and epidermal cells. Cd extrusion was higher in the AtPDR8-over-expressing plants in a flux assay using isolated protoplasts and radioactive <SUP>109</SUP>Cd, and was lower in the RNAi transgenic plants than in the wild-type. Together, these data strongly support a role for AtPDR8 as an efflux pump of Cd<SUP>2+</SUP> or Cd conjugates at the plasma membrane of Arabidopsis cells. As AtPDR8 has been suggested to be involved in the pathogen response and in the transport of chemicals that mediate pathogen resistance, this ABC protein is likely to transport a very broad range of substrates.</P>

Common Functions or Only Phylogenetically Related? The Large Family of PLAC8 Motif-Containing/PCR Genes

송원용,Stefan Hörtensteiner,Rie Tomioka,이영숙,Enrico Martinoia 한국분자세포생물학회 2011 Molecules and cells Vol.31 No.1

PLAC8 motif-containing proteins form a large family and members can be found in fungi, algae, higher plants and animals. They include the PCR proteins of plants. The name giving PLAC8 domain was originally found in a protein residing in the spongiotrophoblast layer of the placenta of mammals. A further motif found in a large number of these proteins including several PCR proteins is the CCXXXXCPC or CLXXXXCPC motif. Despite their wide distribution our knowledge about the function of these proteins is very limited. For most of them two membrane-spanning -helices are predicted, indicating that they are membrane associated or membrane intrinsic proteins. In plants PLAC8 motif-containing proteins have been described to be implicated in two very different functions. On one hand, it has been shown that they are involved in the determination of fruit size and cell number. On the other hand, two members of this family, AtPCR1 and AtPCR2 play an important role in transport of heavy metals such as cadmium or zinc. Transport experiments and approaches to model the 3_D structure of these proteins indicate that they could act as transporters for these divalent cations by forming homomultimers. In this minireview we discuss the present knowledge about this protein family and try to give an outlook on how to integrate the different proposed functions into a common picture about the role of PLAC8 motif-containing proteins.

Postmeiotic development of pollen surface layers requires two Arabidopsis ABCG-type transporters

Yim, S.,Khare, D.,Kang, J.,Hwang, J. U.,Liang, W.,Martinoia, E.,Zhang, D.,Kang, B.,Lee, Y. Springer International 2016 Plant cell reports Vol. No.

<P>Two Arabidopsis ABC transporters, ABCG1 and ABCG16, are expressed in the tapetal layer, specifically after postmeiotic microspore release, and play important roles in pollen surface development. The male gametophytic cells of terrestrial plants, the pollen grains, travel far before fertilization, and thus require strong protective layers, which take the form of a pollen coat and a pollen wall. The protective surface structures are generated by the tapetum, the tissue surrounding the developing gametophytes. Many ABC transporters, including Arabidopsis thaliana ABCG1 and ABCG16, have been shown to play essential roles in the development of such protective layers. However, the details of the mechanism of their function remain to be clarified. In this study, we show that ABCG1 and ABCG16 are localized at the plasma membrane of tapetal cells, specifically after postmeiotic microspore release, and play critical roles in the postmeiotic stages of male gametophyte development. Consistent with this stage-specific expression, the abcg1 abcg16 double knockout mutant exhibited defects in pollen development after postmeiotic microspore release; their microspores lacked intact nexine and intine layers, exhibited defects in pollen mitosis I, displayed ectopic deposits of arabinogalactan proteins, failed to complete cytokinesis, and lacked sperm cells. Interestingly, the double mutant exhibited abnormalities in the internal structures of tapetal cells, too; the storage organelles of tapetal cells, tapetosomes and elaioplasts, were morphologically altered. Thus, this work reveals that the lack of ABCG1 and ABCG16 at the tapetal cell membrane causes a broad range of defects in pollen, as well as in tapetal cells themselves. Furthermore, these results suggest that normal pollen surface development is necessary for normal development of the pollen cytoplasm.</P>

Identification of amino acid residues important for the arsenic resistance function of<i>Arabidopsis</i>ABCC1

Zhang, Jie,Hwang, Jae-Ung,Song, Won-Yong,Martinoia, Enrico,Lee, Youngsook Wiley (John WileySons) 2017 FEBS letters Vol.591 No.4

<P>The Arabidopsis ATP-Binding Cassette (ABC) transporter ABCC1 sequesters arsenic (As)-phytochelatin conjugates into the vacuole, thereby conferring As resistance. Here, we report the results of a screen for phosphorylation-dependent regulation sites of AtABCC1. Variants of AtABCC1 harboring mutations that replaced amino acid residues Tyr(682), Tyr(709), Tyr(822), Ser(846), Ser(1278), or Thr(1408) with alanine confer reduced resistance and decrease the intracellular As content relative to wild-type AtABCC1 when heterologously expressed in the SM7 yeast strain. This suggests that these mutations compromise the vacuolar sequestration of As by AtABCC1. Furthermore, through a phosphomimic mutant study, we found that phosphorylation of Ser(846) is required for the As resistance function of AtABCC1. Our analysis provides a first clue as to the phosphorylation-mediated regulation of AtABCC1 activity.</P>

Overexpression of AtABCG36 improves drought and salt stress resistance in <i>Arabidopsis</i>

Kim, Do-Young,Jin, Jun-Young,Alejandro, Santiago,Martinoia, Enrico,Lee, Youngsook Blackwell Publishing Ltd 2010 Physiologia Plantarum Vol.139 No.2

<P>Drought and salt are major abiotic stresses that adversely affect crop productivity. Thus, identification of factors that confer resistance to these stresses would pave way to increasing agricultural productivity. When grown on soil in green house longer than 5 weeks, transgenic <I>Arabidopsis</I> plants that overexpress an ATP-binding cassette (ABC) transporter, AtABCG36/AtPDR8, produced higher shoot biomass and less chlorotic leaves than the wild-type. We investigated whether the improved growth of AtABCG36-overexpressing plants was due to their improved resistance to abiotic stresses, and found that AtABCG36-overexpressing plants were more resistant to drought and salt stress and grew to higher shoot fresh weight (FW) than the wild-type. On the contrary, T-DNA insertional knockout lines were more sensitive to drought stress than wild-type and were reduced in shoot FW. To understand the mechanism of enhanced salt and drought resistance of the AtABCG36 overexpressing plants, we measured sodium contents and found that AtABCG36 overexpressing plants were lower in sodium content than the wild-type. Our data suggest that AtABCG36 contributes to drought and salt resistance in <I>Arabidopsis</I> by a mechanism that includes reduction of sodium content in plants.</P>

AtATM3 is involved in heavy metal resistance in Arabidopsis.

Kim, Do-Young,Bovet, Lucien,Kushnir, Sergei,Noh, Eun Woon,Martinoia, Enrico,Lee, Youngsook American Society of Plant Physiologists 2006 PLANT PHYSIOLOGY - Vol.140 No.3

<P>AtATM3, an ATP-binding cassette transporter of Arabidopsis (Arabidopsis thaliana), is a mitochondrial protein involved in the biogenesis of iron-sulfur clusters and iron homeostasis in plants. Our gene expression analysis showed that AtATM3 is up-regulated in roots of plants treated with cadmium [Cd(II)] or lead (II); hence, we investigated whether this gene is involved in heavy metal tolerance. We found that AtATM3-overexpressing plants were enhanced in resistance to Cd, whereas atatm3 mutant plants were more sensitive to Cd than their wild-type controls. Moreover, atatm3 mutant plants expressing 35S promoter-driven AtATM3 were more resistant to Cd than wild-type plants. Since previous reports often showed that the cytosolic glutathione level is positively correlated with heavy metal resistance, we measured nonprotein thiols (NPSH) in these mutant plants. Surprisingly, we found that atatm3 contained more NPSH than the wild type under normal conditions. AtATM3-overexpressing plants did not differ under normal conditions, but contained less NPSH than wild-type plants when exposed to Cd(II). These results suggest a role for AtATM3 in regulating cellular NPSH level, a hypothesis that was further supported by our gene expression study. Genetic or pharmacological inhibition of glutathione biosynthesis led to the elevated expression of AtATM3, whereas expression of the glutathione synthase gene GSH1 was increased under Cd(II) stress and in the atatm3 mutant. Because the closest homolog of AtATM3 in fission yeast (Schizosaccharomyces pombe), HMT1, is a vacuolar membrane-localized phytochelatin-Cd transporter, it is tempting to speculate that glutathione-Cd(II) complexes formed in the mitochondria are exported by AtATM3. In conclusion, our data show that AtATM3 contributes to Cd resistance and suggest that it may mediate transport of glutamine synthetase-conjugated Cd(II) across the mitochondrial membrane.</P>