Journal: Frontiers in Cell and Developmental Biology
Article Title: Multimodal regulation of the osteoclastogenesis process by secreted group IIA phospholipase A 2
doi: 10.3389/fcell.2022.966950
Figure Lengend Snippet: The LLKYK cyclic peptide inhibits RANKL-induced Mmp-9 transcription and osteoclast fusion of RAW264.7 macrophages. (A) Alignment of sPLA 2 -IIA sequences from mus musculus (UniProtKB - P31482), homo sapiens (UniProtKB - P14555), and C. durissus (UniProtKB - P24027). Consensus symbols indicate residue conservation, as calculated with the Clustal Omega program. The pentapeptide sequences are boxed in red, and the catalytic histidine residue in the human sPLA 2 -IIA sequence is shown in red-letter code. (B–D) RAW264.7 cells were treated without (w/o) or with 15–30 ng/mL RANKL for 72 h, in presence of the carriers (‒), or 10 nM BPB, or 250 μM of the indicated peptides (LLKYK from the murine sPLA 2 -IIA sequence, FLSYK from that of human sPLA 2 -IIA, WDIYR from that of C. durissus ). The differentiation markers were quantified by real-time qPCR analysis, and normalized using β2-microglobulin expression, as the housekeeping gene. Data are expressed as fold of RANKL, and are means ± SEM of at least three independent experiments. (E) RAW264.7 cells were treated without (w/o) or with of 15 ng/mL RANKL for 72 h, in presence of the indicated peptides (250 μM), or with PBS as carrier. Osteoclast syncytium formation was determined as number of nuclei/cell, by fluorescence microscopy. Data are means ± SE of six independent experiments. * p < 0.05; ** p < 0.01; *** p < 0.005 versus correspondent RANKL (paired Student’s t -tests).
Article Snippet: After 24 and 48 h, cells were double transfected with 125 pmol/well of small-interfering (si)RNAs against sPLA 2 -IIA (si–sPLA 2 -IIA) (murine group II sPLA 2 siRNA, sc-43818, from Santa Cruz Biotecnology, San Diego, CA, United States), or with non-targeting siRNAs (si–NT) (siGENOME non-targeting siRNA pool #2, cat. No. D-001206–14 from Dharmacon, Chicago, IL, United States), using Lipofectamine RNAiMAX reagent (Invitrogen, Carlsbad, CA, United States), according to the manufacturer instructions.
Techniques: Residue, Sequencing, Expressing, Fluorescence, Microscopy