scholarly journals Cytosolic delivery of proteins by cholesterol tagging

2020 ◽  
Vol 6 (25) ◽  
pp. eabb0310
Author(s):  
Wanyi Tai ◽  
Pengfei Zhao ◽  
Xiaohu Gao
Keyword(s):  
Cell Membrane ◽  
Small Molecules ◽  
Protein Delivery ◽  
Defense Mechanism ◽  
Fundamental Problem ◽  
Target Space ◽  
Cell Defense ◽  
Cytosolic Delivery ◽  
Biological Target ◽  
Basic Biology

Protein-based imaging agents and therapeutics are superior in structural and functional diversity compared to small molecules and are much easier to design or screen. Antibodies or antibody fragments can be easily raised against virtually any target. Despite these fundamental advantages, the power and impact of protein-based agents are substantially undermined, only acting on a limited number of extracellular targets because macrobiomolecules cannot spontaneously cross the cell membrane. Conventional protein delivery techniques fail to address this fundamental problem in that protein cargos are predominantly delivered inside cells via endocytosis, a remarkably effective cell defense mechanism developed by Mother Nature to prevent intact biomolecules from entering the cytoplasm. Here, we report a unique concept, noncovalent cholesterol tagging, enabling virtually any compact proteins to permeate through the cell membrane, completely bypassing endocytosis. This simple plug-and-play platform greatly expands the biological target space and has the potential to transform basic biology studies and drug discovery.

scholarly journals A boronic acid–rich dendrimer with robust and unprecedented efficiency for cytosolic protein delivery and CRISPR-Cas9 gene editing

2019 ◽  
Vol 5 (6) ◽  
pp. eaaw8922 ◽  
Author(s):  
Chongyi Liu ◽  
Tao Wan ◽  
Hui Wang ◽  
Song Zhang ◽  
Yuan Ping ◽  
...  
Keyword(s):  
Boronic Acid ◽  
Protein Delivery ◽  
High Efficiency ◽  
Intracellular Delivery ◽  
Cytosolic Protein ◽  
Native Proteins ◽  
Cytosolic Delivery ◽  
Cas9 Protein ◽  
Cargo Proteins ◽  
Positively Charged

Cytosolic protein delivery is of central importance for the development of protein-based biotechnologies and therapeutics; however, efficient intracellular delivery of native proteins remains a challenge. Here, we reported a boronic acid–rich dendrimer with unprecedented efficiency for cytosolic delivery of native proteins. The dendrimer could bind with both negatively and positively charged proteins and efficiently delivered 13 cargo proteins into the cytosol of living cells. All the delivered proteins kept their bioactivities after cytosolic delivery. The dendrimer ensures efficient intracellular delivery of Cas9 protein into various cell lines and showed high efficiency in CRISPR-Cas9 genome editing. The rationally designed boronic acid–rich dendrimer permits the development of an efficient platform with high generality for the delivery of native proteins.

scholarly journals Spatial, Temporal, and Functional Assessment of LC3-Dependent Autophagy inShigella flexneriDissemination

2018 ◽  
Vol 86 (8) ◽  
Author(s):  
Erin Weddle ◽  
Hervé Agaisse
Keyword(s):  
Colonic Mucosa ◽  
Defense Mechanism ◽  
Positive Impact ◽  
Shigella Flexneri ◽  
Wild Type ◽  
Content Type ◽  
Cell Defense ◽  
Membrane Protrusions ◽  
Cell Spread

ABSTRACTShigella flexneridisseminates within the colonic mucosa by displaying actin-based motility in the cytosol of epithelial cells. Motile bacteria form membrane protrusions that project into adjacent cells and resolve into double-membrane vacuoles (DMVs) from which the bacteria escape, thereby achieving cell-to-cell spread. During dissemination,S. flexneriis targeted by LC3-dependent autophagy, a host cell defense mechanism against intracellular pathogens. TheS. flexneritype III secretion system effector protein IcsB was initially proposed to counteract the recruitment of the LC3-dependent autophagy machinery to cytosolic bacteria. However, a recent study proposed that LC3 was recruited to bacteria in DMVs formed during cell-to-cell spread. To resolve the controversy and clarify the role of autophagy inS. flexneriinfection, we tracked dissemination using live confocal microscopy and determined the spatial and temporal recruitment of LC3 to bacteria. This approach demonstrated that (i) LC3 was exclusively recruited to wild-type oricsBbacteria located in DMVs and (ii) theicsBmutant was defective in cell-to-cell spread due to failure to escape LC3-positive as well as LC3-negative DMVs. Failure ofS. flexnerito escape DMVs correlated with late LC3 recruitment, suggesting that LC3 recruitment is the consequence and not the cause of DMV escape failure. Inhibition of autophagy had no positive impact on the spreading of wild-type oricsBmutant bacteria. Our results unambiguously demonstrate that IcsB is required for DMV escape during cell-to-cell spread, regardless of LC3 recruitment, and do not support the previously proposed notion that autophagy countersS. flexneridissemination.

scholarly journals Antioxidant Enzyme Activities and Secondary Metabolite Profiling of Oil Palm Seedlings Treated with Combination of NPK Fertilizers Infected with Ganoderma boninense

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Mahbod Sahebi ◽  
Mohamed M. Hanafi ◽  
Hasmah Mohidin ◽  
M. Y. Rafii ◽  
Parisa Azizi ◽  
...  
Keyword(s):  
Secondary Metabolite ◽  
Oil Palm ◽  
Defense Mechanism ◽  
Elaeis Guineensis ◽  
Growth And Yield ◽  
Stem Rot ◽  
Antioxidant Enzyme Activities ◽  
Npk Fertilizers ◽  
Basal Stem Rot ◽  
Cell Defense

Oil palm (Elaeis guineensis Jacq) is one of the major sources of edible oil. Reducing the effect of Ganoderma, main cause of basal stem rot (BSR) on oil palm, is the main propose of this study. Understanding the oil palm defense mechanism against Ganoderma infection through monitoring changes in the secondary metabolite compounds levels before/after infection by Ganoderma under different fertilizing treatment is required. Oil palm requires macro- and microelements for growth and yield. Manipulating the nutrient for oil palm is a method to control the disease. The 3-4-month-old oil palm seedlings were given different macronutrient treatments to evaluate induction of defense related enzymes and production of secondary metabolite compounds in response to G. boninense inoculation. The observed trend of changes in the infected and uninfected seedlings was a slightly higher activity for β-1,3-glucanases, chitinase, peroxidase, and phenylalanine ammonia-lyase during the process of pathogenesis. It was found that PR proteins gave positive response to the interaction between oil palm seedlings and Ganoderma infection. Although the responses were activated systematically, they were short-lasting as the changes in enzymes activities appeared before the occurrence of visible symptoms. Effect of different nutrients doses was obviously observed among the results of the secondary metabolite compounds. Many identified/unidentified metabolite compounds were presented, of which some were involved in plant cell defense mechanism against pathogens, mostly belonging to alkaloids with bitter-tasting nitrogenous-compounds, and some had the potential to be used as new markers to detect basal stem rot at the initial step of disease.

scholarly journals Σύνθεση και μελέτη μη φυσικών δομών που αλληλεπιδρούν με το ριβοσωμικό RNA

2014 ◽  
Author(s):  
Ιωάννης Μαυρίδης
Keyword(s):  
Protein Synthesis ◽  
Small Molecules ◽  
Binding Sites ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Bacterial Ribosome ◽  
Biological Target ◽  
Pharmaceutical Properties ◽  
A Site ◽  
New Generation

The bacterial ribosome represents the biological target for a variety of known antibiotics, aminoglycosides being the most characteristic example. The pharmaceutical properties of aminoglycosides are due to their ability to bind strongly to the bacterial A-site. This binding interferes with the mechanism of protein synthesis and eventually results in cell death. Nevertheless, despite their former universitality their effectiveness has been greatly diminished by the increasing appearance of resistant bacterial strains. In this thesis, aiming to a new generation of antibiotics based on the aminoglycoside structures, we have designed and synthesized a series of novel, spiro-bicyclic analogues. Selecting amongst the most promising analogues we proceeded to further derivatization by means of proper substitution. The resulting second generation products presented improved antibacterial properties. Furthermore we envisioned and tested a new protocol for indentifying the binding sites of small molecules within the RNA target. Being able to apply such a procedure to molecules with pharmaceutical significance would lead to better clarification of their mechanism of action and easier synthetic protocols of improved analogues.

scholarly journals The effects of quercetin on oxidative stress and fibrosis markers in chronic kidney disease rat model

2017 ◽  
Vol 26 (3) ◽  
pp. 169-77 ◽  
Author(s):  
Kamalia Layal ◽  
Ika S. Perdhana ◽  
Melva Louisa ◽  
Ari Estuningtyas ◽  
Vivian Soetikno
Keyword(s):  
Oxidative Stress ◽  
Fruits And Vegetables ◽  
Defense Mechanism ◽  
Plasma Creatinine ◽  
Control Group ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Sprague Dawley ◽  
Cell Defense ◽  
Gpx Activity

Background: Oxidative stress may play a role in the pathogenesis of (CKD), Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor involved in cell defense mechanism against oxidative stress. In this study, we examined the effect of quercetin, a polyphenplic antioxidant anti fibrosis compund in fruits and vegetables, on the 5/6 nephrectomy-induced CKD progression model rats through modulation of Nrf2 expression.Methods: Male Sprague-Dawley rats were randomly divided into normal control group (C), untreated 5/6 nephrectomy (Nx), quercetin-treated 5/6 nephrectomy (100 mg/kgBW/day orally) (NxQ), and captopril-treated 5/6 nephrectomy (10 mg/kgBW/day orally) (NxK) for 8 weeks. At the end of study, all animals were sacrified. Urine, blood, and kidney tissues were taken for examination of proteinuria, plasma creatinine, urea, malondialdehyde (MDA), glutathione peroxidase (GPx) activity, Nrf2, Keap1, heme oxygenase-1 (HO-1) expressions, and renal fibrosis.Results: Quercetin administration did not affect the level of protein in urine, plasma creatinine, and urea. However, it tended to reduce the level of MDA, increase GPx activity, Nrf2, Keap1, and HO-1 expression as well as the degree of fibrosis.Conclusion: In 5/6 nephrectomized rats, quercetin tended to ameliorate the level of MDA, GPx activity, Nrf2, Keap1, and HO-1 expression. In addition, quercetin tended to decrease the degree of fibrosis in the remnant kidney.

Hydrogel‐Induced Cell Membrane Disruptions Enable Direct Cytosolic Delivery of Membrane‐Impermeable Cargo

2021 ◽  
pp. 2008054
Author(s):  
Jelter Van Hoeck ◽  
Thijs Van de Vyver ◽  
Aranit Harizaj ◽  
Glenn Goetgeluk ◽  
Pieterjan Merckx ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Cytosolic Delivery

scholarly journals Leishmania: manipulation of signaling pathways to inhibit host cell apoptosis

2021 ◽  
Vol 8 ◽  
pp. 204993612110149
Author(s):  
Sandra-Georgina Solano-Gálvez ◽  
Diego-Abelardo Álvarez-Hernández ◽  
Laila Gutiérrez-Kobeh ◽  
Rosalino Vázquez-López
Keyword(s):  
Cell Death ◽  
Host Cell ◽  
Signaling Pathways ◽  
Defense Mechanism ◽  
Morphological Changes ◽  
Wide Spectrum ◽  
Chromatin Condensation ◽  
Mitogen Activated Protein Kinase ◽  
Type I ◽  
Cell Defense

The maintenance of homeostasis in living systems requires the elimination of unwanted cells which is performed, among other mechanisms, by type I cell death or apoptosis. This type of programmed cell death involves several morphological changes such as cytoplasm shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), and plasma membrane blebbing that culminate with the formation of apoptotic bodies. In addition to the maintenance of homeostasis, apoptosis also represents an important defense mechanism for cells against intracellular microorganisms. In counterpart, diverse intracellular pathogens have developed a wide array of strategies to evade apoptosis and persist inside cells. These strategies include the manipulation of signaling pathways involved in the inhibition of apoptosis where mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) play a key role. Leishmania is an intracellular protozoan parasite that causes a wide spectrum of diseases known as leishmaniasis. This parasite displays different strategies, including apoptosis inhibition, to down-regulate host cell defense mechanisms in order to perpetuate infection.

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