Chemical screens for particle-induced macrophage dying identifies kinase inhibitors of phagocytosis as targets for toxicity | Journal of Nanobiotechnology

Chemical screens for particle-induced macrophage dying identifies kinase inhibitors of phagocytosis as targets for toxicity | Journal of Nanobiotechnology


Reagents

The next particles have been bought from Sigma; aluminum oxide nanoparticles (Al2O3, 642991), cerium (IV) oxide nanopowder (CeO2, 700290), cobalt iron oxide nanopowder (CoFe2O4, 7733352), copper (II) oxide nanopowder (CuO, 544868), diamond nanopowder (C: 636428), iron oxide (II, III) nanoparticles (Fe3O4, 900062), nickel (II) oxide nanopowder (NiO, 637130), silicon dioxide (SiO2, S5631), silver nanopowder (Ag, 576832), titanium (IV) oxide anatase nanopowder (TiO2, 637254), uric acid sodium salt (C5H3N4O3Na, U2875), zinc oxide nanoparticles (ZnO, 721077). The next chemical compounds have been bought from Sigma; LOPAC 1280 library (LO4200), CA-074 methyl ester (ME) (C5857), cyclosporin A (30024), ferrostatin-1 (SML0583), necrostatin-1 (N9037), nigericin (N7143), PD173952 (PZ0113), PF431396 (PZ0185), PF562271 (PZ0387), rucaparib (PZ0036), wortmannin (W1628). The next chemical compounds have been bought from Cayman Chemical; AC-YVAD-CMK (10014), Bafilomycin A1 (11038), PF573228 (14924), Z-DEVD-FMK (14414). MCC950 (AG-CR1-3615) and Z-VAD-FMK (AG-CP3-0002) have been bought from AdipoGen. Different chemical compounds have been bought from following distributors; BAY61-3606 (Chemscene, CS-0235), Cytochalasin D (Enzo, BML-T109-0001), GSK143 (Tocris, 6362), Z-LEHD-FMK (R&D Methods, FMK008). poly(dA:dT)/LyoVec (tlrl-patc) was bought from InvivoGen. The next antibodies have been bought from Biolegend; IgG2a isotype management antibody (400516), anti-mouse Cd18 antibody (101410), IgG2b isotype management antibody (400644), anti-mouse/human Cd11b antibody (101248). Anti-Cd36 antibody (ab80080) was bought from Abcam and anti-mouse Cd16/Cd32 antibody was bought from BD Biosciences (553140). Chemical compounds have been ready in DMSO between 10 to 40 mM inventory concentrations apart from nigericin (5 mM in ethanol) and poly(dA:dT)/LyoVec (50 µg/mL in water).

Bone marrow derived macrophage (BMDM)

Bone marrow cell suspensions from femurs and tibias of C57BL/6 mice (6- to 10-week outdated) have been seeded at 5 × 106 cells per plate in non-treated sterile 10 cm plates and grown for 3 days in 10 mL of “BMDM media” consisting of DMEM/F-12 (Thermo, 10565–018), supplemented with 10% heat-inactivated outlined FBS (HyClone, SH30070.03), 1 × penicillin/streptomycin, 1 × non-essential amino acids (Thermo, 11140–050), and 20 ng/mL mouse M-CSF (BioLegend, 576406). On day three, 5 mL of BMDM media have been added on high of 10 mL media already current within the plate and grown till day seven. A step-by-step protocol for bone marrow isolation and culturing [64] have been adopted. Previous to nanoparticle or compound therapy, BMDM have been primed with 200 ng/mL of ultrapure E. coli K12 lipopolysaccharide (LPS) (InvivoGen, LPS-EK Ultrapure) for 3 h in BMDM media. All cells have been incubated in a 5% CO2 incubator at 37 °C. Information for every determine panel have been obtained from the identical batch of cells.

Particle preparation and addition

Particles have been ready as 20 mg/mL inventory answer by including particles to sterile distilled deionized water apart from Fe3O4 which got here as 5 mg/mL inventory. Inventory options have been sonicated for 10 min (200W, 15 s on/5 s off cycles) in ice-cold sonicator tub (Bioruptor UCD-200TM, Cosmo Bio) and added to OPTI-MEM media (Thermo, 31,985–070) at 400 µg/mL focus (2×). This 2× particle answer was blended with equal quantity of OPTI-MEM (both containing compound or antibody) to realize a ultimate focus of 200 µg/mL.

Particle characterization

Inventory options of particles have been sonicated as above and added to OPTI-MEM media at 200 µg/mL focus. The hydrodynamic diameter (dynamic gentle scattering (DLS) technique) and zeta potential have been measured utilizing Zeta-potential and particle dimension analyzer (Otsuka Electronics, ELSZ-2000).

Chemical display screen for particle toxicity (LDH assay) in BMDM

Bone marrow derived macrophage (BMDM) have been seeded at 50,000 cells per effectively in 96-well plates (Corning, 3596), in the future earlier than the display screen. On the day of the display screen, BMDM have been primed for 3 h with 200 ng/mL of LPS in BMDM media. Cells have been then washed as soon as with phosphate buffer saline (PBS) (Thermo, 10010023) and handled with 50 µL of OPTI-MEM containing 20 µM of the chemical compounds from LOPAC library and 200 µg/mL of particles. After 3 h incubation, ranges of lactate dehydrogenase (LDH) launched into supernatants have been measured utilizing a Cytotoxicity Detection Equipment (LDH) Plus (Roche, 04 744 934 001) in keeping with the producer’s protocol. Briefly, 100 µL of LDH assay reagent have been added to every effectively, incubated for five min at room temperature, and response was stopped by including 50 µL of cease answer. Absorbance was measured at 490 nm and 600 nm on Synergy HTX multi-mode reader. Background sign (600 nm) was subtracted from assay sign (490 nm) to acquire LDH assay worth. LDH assay values of all wells have been normalized to the in-plate basal (untreated; n = 4) and most (lysis buffer handled; n = 4) wells as; (goal LDH worth–basal LDH worth)/(most LDH worth–basal LDH worth) × 100%. The normalized LDH worth of compound handled wells have been normalized to in-plate particle-treated wells (n = 8) and expressed as; (Compound and nanoparticle handled LDH worth–Nanoparticle solely LDH worth)/(Nanoparticle solely LDH worth) × 100%. Particulars of screening together with workflow are described in Further file 1: Desk S1, Fig. S9.

Particle therapy in further cell sorts

C2C12 mouse myoblasts (CRL-1772) and Hepa1-6 mouse hepatocarcinoma cells (CRL-1830) have been bought from ATCC. Spinoff of HEK293T human embryonic kidney cells (632180) have been bought from Clontech. All cells have been grown in DMEM (Sigma, D6429) supplemented with 10% heat-inactivated outlined FBS and 1 × penicillin/streptomycin. HEK293T and Hepa1-6 have been seeded at 50,000 cells per effectively and C2C12 have been seeded at 20,000 cells per effectively at 100 μL quantity per effectively in 96-well plate in the future earlier than the display screen. Cells have been incubated with particles (200 μg/mL) in OPTI-MEM media for 3 h.

Immunoblotting

BMDM have been seeded at 5 × 105 cells per effectively in 1 mL of BMDM media in 12-well plates (Corning, 353043) the day earlier than therapy. Cells have been primed with 200 ng/mL LPS for 3 h adopted by particle and compound therapy in OPTI-MEM at 500 µL quantity.

OPTI-MEM have been collected as supernatant and centrifuged at 14,000 ×g for 1 min to eradicate cell particles. The remaining cells have been collected in 100 µL of RIPA buffer (Thermo, 89901) containing 1 × focus of protease/phosphatase inhibitors (Thermo, 78440). Proteins within the cell lysates have been quantified utilizing BCA assay package (Thermo, 23227) in keeping with producer’s protocol. Quantity of whole protein have been adjusted with RIPA buffer for equal loading and 1 quantity of 4 × Laemmli buffer (Bio-Rad, 1610747) containing 1.43 M β-mercaptoethanol (Sigma, M-3148) have been added to three quantity of adjusted protein lysate. To extract proteins from supernatant, 500 µL of methanol and 125 µL of chloroform have been added to 500 µL of supernatant (OPTI-MEM) and vortexed for 10 s. The combination have been centrifuged at 14,000 ×g for five min and higher part was eliminated. The center protein layer and backside layer have been washed by gently including 500 µL of methanol and centrifuged once more at 14,000 ×g for five min. The supernatant was eliminated and remaining protein pellet was dried at 50 °C for five min. Protein pellet was resuspended in 60 µL of 1 × Laemmli buffer containing 355 mM β-mercaptoethanol. All protein samples have been heated for five min at 95 °C for denaturation and have been separated by SDS-PAGE, transferred to PVDF membrane, and have been immunoblotted. The first antibodies have been mouse IL-1β (R&D, AF-401-NA; 1:1,000 (v/v) dilution), mouse caspase-1 (Santa Cruz, sc-514; 1:1,000 (v/v) dilution), human and mouse beta actin (Cell Signaling, 4970; 1:2,000 (v/v) dilution). Secondary antibodies have been HRP-conjugated anti-rabbit IgG (Cell Signaling, 7074) and anti-goat IgG (R&D, HAF019) at a 1:2,000 (v/v) dilution. Blocking and first antibody incubation have been carried out in 5% bovine serum albumin (BSA) (Sigma, A7906) in T-TBS (Tris-buffered saline (TBS) containing 0.1% Tween-20 (Sigma, P1379)). Secondary antibody incubation have been carried out in T-TBS with out BSA. Blocking was carried out for 1 h at room temperature, major antibody incubation for in a single day at 4 °C, and secondary antibody incubation for 1 h at room temperature.

Lysosomal membrane permeabilization

Lysosomal membrane permeabilization was detected by measuring cathepsin B launch into the cytosol following a broadcast protocol [65]. Briefly, 2.5 × 105 BMDM cells have been seeded in 24-well plates the day earlier than the assay and primed for 3 h with 200 ng/mL LPS on the day of the assay. BMDM have been then handled with particles at 200 µg/mL focus for 30 min in 250 µL of OPTI-MEM per effectively. BMDM have been washed as soon as with PBS. Plasma membrane permeabilization was carried out by including 200 µL of digitonin extraction buffer (250 mM sucrose, 10 mM KCl, 1.5 mM MgCl2, 1 mM EDTA, 1 mM EGTA, 20 mM HEPES, 0.5 mM Pefabloc (Roche, 11873601001), pH 7.5) containing 15 µg/mL of digitonin (Sigma, D141) and incubated on ice for 10 min with mild rocking. Permeabilization of each the plasma membrane and the lysosomal membrane have been carried out by including 200 µL of digitonin extraction buffer containing 200 µg/mL of digitonin and incubated on ice for 10 min with mild rocking. Cathepsin B exercise in digitonin extraction buffer have been measured by including 50 µL of samples extracted with digitonin extraction buffer with 50 µL of response buffer containing 50 mM sodium acetate, 4 mM EDTA, 8 mM DTT, 0.5 mM Pefabloc, 50 μM zFR-AFC (Enzo, ALX260-129-M005) in black-walled clear-bottom 96-well plates (BD Falcon, 353219). The response was monitored by measuring fluorescence (Ex 360 nm/Em 528 nm) as soon as each minute for 20 min at 30 °C temperature utilizing Synergy HTX multi-mode reader. The change in fluorescence over time was used to calculate enzyme exercise. To normalize for variation in plasma membrane permeabilization, LDH exercise within the digitonin extraction buffer have been assessed utilizing Cytotoxicity Detection Equipment (LDH) Plus. Cathepsin B exercise have been then divided by LDH launch worth to calculate normalized cathepsin B exercise. Normalized cathepsin B exercise for 15 μg/mL digitonin wells have been divided by normalized cathepsin B exercise from 200 μg/mL digitonin wells to calculate lysosomal membrane permeabilization, represented as p.c of most cathepsin B exercise.

MTT assay

BMDM have been seeded at 50,000 cells per effectively in clear 96-well plates at 100 µL quantity per effectively (Corning, 3596), in the future earlier than the assay. Following 3 h LPS priming and three h particle therapy in OPTI-MEM, cells have been incubated with phenol-free DMEM (Thermo, 31053028) containing 0.5 mg/mL of MTT (M6494) for 1 h in 37 °C CO2 incubator. Media containing MTT have been eliminated and 50 µL of DMSO have been added to every effectively to dissolve formazan crystal. Absorbance was recorded at 540 nm on Synergy HTX multi-mode reader. The info have been normalized to the typical worth of untreated detrimental management wells and represented as p.c of no particle management.

Intracellular ATP

BMDM have been seeded at 50,000 cells per effectively at 100 µL quantity per effectively in white-walled clear-bottom 96-well plates (BD Falcon, 353377). Intracellular ATP was measured utilizing CellTiter Glo (Promega, G7571) in keeping with the producer’s protocol. Briefly, 50 µL of reconstituted CellTiter Glo reagent was added to every effectively, incubated for 10 min at room temperature in darkish, and luminescence was measured utilizing Synergy HTX multi-mode reader. The info have been normalized to the typical worth of untreated detrimental management wells and represented as p.c of no particle management.

Intracellular potassium

BMDM have been seeded at 5 × 105 cells per effectively in 1 mL of BMDM media in 12-well plates (Corning, 353043). Following 3 h LPS priming and three h particle therapy, cells have been washed with PBS twice, and cell lysates have been collected in 2 mL 10% nitric acid (Wako, 149–06845). Intracellular potassium was measured utilizing a BWB-XP flame photometer (BWB Applied sciences) and KCl (Sigma, 24–5550) dilution sequence was used to generate commonplace curve. The info have been normalized to the typical worth of untreated detrimental management wells and represented as p.c of no particle management.

E. coli uptake assay

BMDM have been seeded at 50,000 cells per effectively in black-walled clear-bottom 96-well plates (BD Falcon, 353,219). Following 3 h LPS priming, cells have been handled with 5 µM of compounds and 0.5 mg/mL of pHrodo Crimson E. coli (Thermo, P35361) in OPTI-MEM at 100 µL quantity. After 1 h incubation in 37 °C CO2 incubator, cells have been washed twice with PBS and changed with 100 µL of PBS. Fluorescence sign (Ex 560 nm/Em 585 nm) was measured utilizing a Synergy HTX multi-mode reader. Fluorescent indicators have been normalized to the in-plate basal (with out pHrodo Crimson E. coli; n = 4) and most (with pHrodo E. coli; n = 4) wells as; (goal sign – basal sign)/(most sign – basal sign) × 100%.

Move cytometric evaluation

BMDM have been seeded at 5 × 105 cells per effectively in 1 mL media in 12-well tissue tradition handled plates. For reactive oxygen species (ROS) measurement, cells have been incubated with 500 µL OPTI-MEM containing 10 µM CM-H2DCFDA (Thermo, C6827) and incubated for 20 min at 37 °C in a CO2 incubator. Cells have been indifferent utilizing TrypLE (Thermo, 12604–021) and analyzed utilizing a FACS Calibur (BD Bioscience) with Ex 488 nm/Em 530 nm. Gating methods are described in Further file 1: Fig. S7. All FACS knowledge have been analyzed with FlowJo (v10.8).

Transmission electron microscopy (TEM)

BMDM have been mounted in 2% paraformaldehyde and a pair of% glutaraldehyde in 0.1 M phosphate buffer (pH 7.4) for 30 min at 4 °C. Cells have been then mounted in 2% glutaraldehyde in 0.1 M phosphate buffer in a single day at 4 °C. Cells have been washed 3 times in 0.1 M phosphate buffer and post-fixed with 2% osmium tetroxide in 0.1 M phosphate buffer for 1 h at 4 °C. Cells have been then dehydrated as follows; 50% ethanol (5 min, 4 °C), 70% ethanol (5 min, 4 °C), 90% ethanol (5 min, room temperature), 100% ethanol (5 min, room temperature, whole 3 instances). The cells have been then transferred to an EM embedding resin Quetol-812 (Nissin EM, 340-H) and polymerized for 48 h at 60 °C. The polymerized resins have been sectioned at 70 nm with a diamond knife utilizing Ultracut-UCT ultramicrotome (Leica), mounted on copper grids, and stained with 2% uranyl acetate at room temperature for 15 min. Samples have been then washed with distilled water adopted by secondary stain with Lead stain answer (Sigma, 18–0875-2-25ML-J) at room temperature for 3 min. The grids have been noticed on a transmission electron microscope (JEOL, JEM-1400Plus) at an accelerated voltage of 100 kV. Digital photos (3296 × 2472 pixels) have been taken with a CCD digital camera (JEOL, EM-14830RUBY2).

Information visualization

Heatmap view of assay knowledge have been generated utilizing matrix visualization and evaluation software program Morpheus (https://software program.broadinstitute.org/morpheus). Common linkage hierarchical clustering was carried out utilizing Euclidean distance for visualizing patterns within the inhibitory profiles.

Statistical evaluation

Statistical significance was assessed utilizing odd one-way and two-way ANOVA adopted by Bonferroni’s a number of comparability with Prism 8 (8.4.3). Spearman rank correlation values and four-parameter dose–response curves have been generated with Prism 8 (8.4.3). For chemical screens, Z values akin to the 50% lower, a threshold used to establish major hits, are indicated in Further file 1: Fig. S5.

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