scholarly journals Assessing Photosensitized Membrane Damage: Available Tools and Comprehensive Mechanisms

2021 ◽  
Author(s):  
Laura Gonçalves Rezende ◽  
Thiago Teixeira Tasso ◽  
Pedro Henrique Silva Candido ◽  
Mauricio S. Baptista
Keyword(s):  
Membrane Damage

IMPACT OF SORBITOL- INDUCED OSMOTIC STRESS ON SOME BIOCHEMICAL TRAITS OF POTATO IN VITRO

2020 ◽  
Vol 51 (4) ◽  
pp. 1038-1047
Author(s):  
Mawia & et al.
Keyword(s):  
Ascorbic Acid ◽  
Osmotic Stress ◽  
Cytoplasmic Membrane ◽  
Genotypic Variation ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Culture Collection ◽  
Nutritive Medium ◽  
Starting Point

This study had as principal objective identification of osmotic-tolerant potato genotypes by using "in vitro" tissue culture and sorbitol as a stimulating agent, to induce water stress, which was added to the  culture nutritive medium in different concentration (0,50, 110, 220, 330 and 440 mM).  The starting point was represented by plantlets culture collection, belonging to eleven potato genotypes: Barcelona, Nectar, Alison, Jelly, Malice, Nazca, Toronto, Farida, Fabulla, Colomba and Spunta. Plantlets were multiplied between two internodes to obtain microcuttings (in sterile condition), which were inoculated on medium. Sorbitol-induced osmotic stress caused a significant reduction in the ascorbic acid, while the concentration of proline, H2O2 and solutes leakage increased compared with the control. Increased the proline content prevented lipid peroxidation, which played a pivotal role in the maintenance of membrane integrity under osmotic stress conditions. The extent of the cytoplasmic membrane damage depends on osmotic stress severity and the genotypic variation in the maintenance of membranes stability was highly associated with the ability of producing more amounts of osmoprotectants (proline) and the non-enzymic antioxidant ascorbic acid in response to osmotic stress level. The results showed that the genotypes Jelly, Nectar, Allison, Toronto, and Colomba are classified as highly osmotic stress tolerant genotypes, while the genotypes Nazca and Farida are classified as osmotic stress susceptible ones.

Membrane Damage Induced by Amyloid Beta and a Potential Link with Neuroinflammation

2016 ◽  
Vol 22 (10) ◽  
pp. 1295-1304 ◽  
Author(s):  
Eduardo J. Fernandez-Perez ◽  
Christian Peters ◽  
Luis G. Aguayo
Keyword(s):  
Amyloid Beta ◽  
Membrane Damage ◽  
Potential Link

scholarly journals Regulation of divalent metal ions to the aggregation and membrane damage of human islet amyloid polypeptide oligomers

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12815-12825
Author(s):  
Yajie Wang ◽  
Feihong Meng ◽  
Tong Lu ◽  
Chunyun Wang ◽  
Fei Li
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Membrane Damage ◽  
Islet Amyloid Polypeptide ◽  
Divalent Metal ◽  
Human Islet ◽  
Divalent Metal Ions ◽  
Islet Amyloid ◽  
Induced Membrane ◽  
Human Islet Amyloid Polypeptide

Their is a counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the metal binding in the activity of hIAPP induced membrane damage.

scholarly journals Salinity Stress in Potato: Understanding Physiological, Biochemical and Molecular Responses

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 545
Author(s):  
Kumar Nishant Chourasia ◽  
Milan Kumar Lal ◽  
Rahul Kumar Tiwari ◽  
Devanshu Dev ◽  
Hemant Balasaheb Kardile ◽  
...  
Keyword(s):  
Salt Stress ◽  
Osmotic Stress ◽  
Salinity Stress ◽  
Crop Production ◽  
Antioxidant Activities ◽  
Water Status ◽  
Membrane Damage ◽  
Mitigation Strategies ◽  
Ammonium Compound ◽  
Molecular Responses

Among abiotic stresses, salinity is a major global threat to agriculture, causing severe damage to crop production and productivity. Potato (Solanum tuberosum) is regarded as a future food crop by FAO to ensure food security, which is severely affected by salinity. The growth of the potato plant is inhibited under salt stress due to osmotic stress-induced ion toxicity. Salinity-mediated osmotic stress leads to physiological changes in the plant, including nutrient imbalance, impairment in detoxifying reactive oxygen species (ROS), membrane damage, and reduced photosynthetic activities. Several physiological and biochemical phenomena, such as the maintenance of plant water status, transpiration, respiration, water use efficiency, hormonal balance, leaf area, germination, and antioxidants production are adversely affected. The ROS under salinity stress leads to the increased plasma membrane permeability and extravasations of substances, which causes water imbalance and plasmolysis. However, potato plants cope with salinity mediated oxidative stress conditions by enhancing both enzymatic and non-enzymatic antioxidant activities. The osmoprotectants, such as proline, polyols (sorbitol, mannitol, xylitol, lactitol, and maltitol), and quaternary ammonium compound (glycine betaine) are synthesized to overcome the adverse effect of salinity. The salinity response and tolerance include complex and multifaceted mechanisms that are controlled by multiple proteins and their interactions. This review aims to redraw the attention of researchers to explore the current physiological, biochemical and molecular responses and subsequently develop potential mitigation strategies against salt stress in potatoes.

scholarly journals A cryo–electron tomography workflow reveals protrusion-mediated shedding on injured plasma membrane

2021 ◽  
Vol 7 (13) ◽  
pp. eabc6345
Author(s):  
Shrawan Kumar Mageswaran ◽  
Wei Yuan Yang ◽  
Yogaditya Chakrabarty ◽  
Catherine M. Oikonomou ◽  
Grant J. Jensen
Keyword(s):  
Plasma Membrane ◽  
Molecular Mechanisms ◽  
Electron Tomography ◽  
Membrane Damage ◽  
Light And Electron Microscopy ◽  
Actin Dynamics ◽  
Endosomal Sorting ◽  
Plasma Membrane Damage ◽  
Cryo Electron Tomography ◽  
Vacuolar Protein

Cryo–electron tomography (cryo-ET) provides structural context to molecular mechanisms underlying biological processes. Although straightforward to implement for studying stable macromolecular complexes, using it to locate short-lived structures and events can be impractical. A combination of live-cell microscopy, correlative light and electron microscopy, and cryo-ET will alleviate this issue. We developed a workflow combining the three to study the ubiquitous and dynamic process of shedding in response to plasma membrane damage in HeLa cells. We found filopodia-like protrusions enriched at damage sites and acting as scaffolds for shedding, which involves F-actin dynamics, myosin-1a, and vacuolar protein sorting 4B (a component of the ‘endosomal sorting complex required for transport’ machinery). Overall, shedding is more complex than current models of vesiculation from flat membranes. Its similarities to constitutive shedding in enterocytes argue for a conserved mechanism. Our workflow can also be adapted to study other damage response pathways and dynamic cellular events.

scholarly journals Amphipathic Peptide Antibiotics with Potent Activity against Multidrug-Resistant Pathogens

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 438
Author(s):  
Jingru Shi ◽  
Chen Chen ◽  
Dejuan Wang ◽  
Ziwen Tong ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Membrane Damage ◽  
Multidrug Resistant ◽  
Peptide Antibiotics ◽  
Biofilm Inhibition ◽  
Amphipathic Peptide ◽  
Host Defense Peptides ◽  
Gram Negative ◽  
Wide Range ◽  
New Antibiotics ◽  
Low Toxicity

The emergence and prevalence of multidrug-resistant (MDR) bacteria have posed a serious threat to public health. Of particular concern are methicillin-resistant Staphylococcus aureus (MRSA) and blaNDM, mcr-1 and tet(X)-positive Gram-negative pathogens. The fact that few new antibiotics have been approved in recent years exacerbates this global crisis, thus, new alternatives are urgently needed. Antimicrobial peptides (AMPs) originated from host defense peptides with a wide range of sources and multiple functions, are less prone to achieve resistance. All these characteristics laid the foundation for AMPs to become potential antibiotic candidates. In this study, we revealed that peptide WW307 displayed potent antibacterial and bactericidal activity against MDR bacteria, including MRSA and Gram-negative bacteria carrying blaNDM-5, mcr-1 or tet(X4). In addition, WW307 exhibited great biofilm inhibition and eradication activity. Safety and stability experiments showed that WW307 had a strong resistance against various physiological conditions and displayed relatively low toxicity. Mechanistic experiments showed that WW307 resulted in membrane damage by selectively targeting bacterial membrane-specific components, including lipopolysaccharide (LPS), phosphatidylglycerol (PG), and cardiolipin (CL). Moreover, WW307 dissipated membrane potential and triggered the production of reactive oxygen species (ROS). Collectively, these results demonstrated that WW307 represents a promising candidate for combating MDR pathogens.

scholarly journals Diamond Nanoparticles-Porphyrin mTHPP Conjugate as Photosensitizing Platform: Cytotoxicity and Antibacterial Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1393
Author(s):  
Carolina Ramos Hurtado ◽  
Gabriela Ramos Hurtado ◽  
Gabrielle Lupeti de Cena ◽  
Rafaela Campos Queiroz ◽  
Alexandre Vieira Silva ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Aqueous Suspension ◽  
Membrane Damage ◽  
Covalent Bond ◽  
Bacterial Suspension ◽  
Hydrodynamic Diameter ◽  
Sem Images ◽  
Murine Embryonic Fibroblast ◽  
Diamond Nanoparticles ◽  
Bacterial Growth Inhibition

Conjugation of photosensitizers (PS) with nanoparticles has been largely used as a strategy to stabilize PS in the biological medium resulting in photosensitizing nanoparticles of enhanced photoactivity. Herein, (Meso-5, 10, 15, 20-tetrakis (3-hydroxyphenyl) phorphyryn (mTHPP) was conjugated with diamond nanoparticles (ND) by covalent bond. Nanoconjugate ND-mTHPP showed suitable stability in aqueous suspension with 58 nm of hydrodynamic diameter and Zeta potential of −23 mV. The antibacterial activity of ND-mTHPP was evaluated against Escherichia coli for different incubation times (0–24 h). The optimal activity was observed after 2 h of incubation and irradiation (660 nm; 51 J/cm2) performed right after the addition of ND-mTHPP (100 μg/mL) to the bacterial suspension. The inhibitory activity was 56% whereas ampicillin at the same conditions provided only 14% of bacterial growth inhibition. SEM images showed agglomerate of ND-mTHPP adsorbed on the bacterial cell wall, suggesting that the antimicrobial activity of ND-mTHPP was afforded by inducing membrane damage. Cytotoxicity against murine embryonic fibroblast cells (MEF) was also evaluated and ND-mTHPP was shown to be noncytotoxic since viability of cells cultured for 24 h in the presence of the nanoconjugate (100 μg/mL) was 78%. Considering the enhanced antibacterial activity and the absence of cytotoxic effect, it is possible to consider the ND-mTHPP nanoconjugate as promising platform for application in antimicrobial photodynamic therapy (aPDT).

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