human gas6 hgas6  (R&D Systems)

Journal: bioRxiv

Article Title: Efferocytosis Remodels Osteoclast Metabolism and Enhances Antibacterial Defense

doi: 10.64898/2026.10.13.759003

Figure Lengend Snippet: a , Schematic of the experimental design for Staphylococcus aureus -induced bone infection. b,c , Kinetic analysis of bone marrow neutrophil responses after infection, showing neutrophil frequency ( b ) and apoptotic neutrophil frequency ( c ) at the indicated time points. d,e , Representative immunofluorescence images of infected bone marrow ( d ) and quantification of apoptotic neutrophils and total apoptotic cells ( e ). Ly6G (red), TUNEL (green), and DAPI staining are shown. White arrows indicate apoptotic neutrophils, and yellow arrows indicate other apoptotic cells. Quantification shows the densities of apoptotic neutrophils and total apoptotic cells (cells/mm²), together with the proportion of apoptotic cells identified as neutrophils. Scale bars, 50 µm (main images) and 10 µm (insets). f,g , Immunoblot analysis of GAS6 expression in whole bone marrow lysates collected at the indicated time points after infection ( f ), with densitometric quantification normalized to β-actin ( g ). h , Quantification of osteoclast abundance at the indicated time points following bone infection, expressed as N.Mu.OC/B.Pm (number of multinucleated osteoclasts per bone perimeter). i , Representative TRAP-stained femoral sections from uninfected and infected mice, with quantification of osteoclasts containing apoptotic cell-associated signals. Arrows indicate osteoclasts undergoing efferocytosis. Scale bars, 50 µm. j , Representative bone sections from Ly6G-tdTomato reporter mice after infection showing CTSK⁺ osteoclasts (green), tdTomato⁺ neutrophil-derived signals (red), and DAPI staining (blue). Arrows indicate neutrophil-derived signals within osteoclast boundaries. Scale bars, 20 µm (main images) and 10 µm (insets). Data are presented as mean ± s.d. Statistical significance was assessed using one-way ANOVA with Tukey’s multiple comparisons test ( c,g,h,i ). n = 4 mice per group for control, day 1 and day 7 and n = 5 for day 3, day 10 and day 14 ( b,c ); n = 3 mice per time point ( e ), n = 4 ( g ), and n = 5 ( h,i ). Each point represents one mouse; linked points in e denote measurements from the same mouse.

Article Snippet: Membranes were blocked with 5% nonfat milk in TBST (TBS containing 0.1% Tween-20) for 1 h at room temperature and then incubated overnight at 4°C with the indicated primary antibodies against GAS6 (MedChemExpress; HY-P85881), MERTK (Proteintech; 27900-1-AP), AXL (MedChemExpress; HY-P81198), HIF-1α (Proteintech; 82989-4-RR), GLUT1 (Proteintech; 21829-1-AP), and OXPHOS Cocktail (Proteintech; PK30006).

Techniques: Infection, Analysis, Immunofluorescence, TUNEL Assay, Staining, Western Blot, Expressing, Derivative Assay, Control

Journal: Advanced Science

Article Title: Fc‐Dependent Targeting of the GAS6–MERTK Axis With Monoclonal and Bispecific Antibodies Overcomes Drug Resistance Across EGFR Mutations in Exons 19, 20, and 21

doi: 10.1002/advs.78290

Figure Lengend Snippet: GAS6 supports survival of TKI‐treated cells; blocking it delays resistance to osimertinib in an animal model. (A) Data were taken from a clinical trial, NCT03433469 (EGFR‐positive NSCLC patients). Patients were treated with osimertinib, and the cohort was segregated into Treatment Naïve (TN), Residual Disease (RD), and Progressive Disease (PD). The volcano plot presents delayed early genes that differ between patients with RD (4 samples) and PD (3 samples). MERTK, AXL, GAS6, and EGFR are highlighted in red. The average log2 of the fold change (FC) and the p ‐values are presented in a table. (B) GAS6 knockout (KO) and GAS6‐overexpressing (OX) PC9 cells were generated. Cells (500/well) were seeded in 96‐well plates and grown for 9 days. The cells were then fixed and stained with crystal violet to estimate cell numbers on specific days. *** , p < 0.001; **** , p < 0.0001. (C) The indicated derivatives of PC9 cells (1 × 10 3 , per well) were seeded in 96‐well plates. Next, cells were treated for 72 h with different concentrations of osimertinib. Cell viability was determined using a colorimetric assay. The histogram depicts cell viability under 10 n m osimertinib. (D‐F) PC9 cells (2.5 × 10 6 ) were injected subcutaneously in the flanks of CD1‐nu/nu mice. Once the tumor became palpable, 5–7 mice were randomized into the indicated 4 groups and treated for five weeks with either osimertinib (10 mg/kg) or/and a mAb197 against GAS6 (0.2 mg per injection; twice weekly). Individual tumor volumes (D) average tumor volumes per group, along with the average recorded on day 47 (E), and Kaplan‐Meier survival plots (F) are shown. Survival analysis was performed using Holm–Šídák's multiple comparisons test to assess statistical significance between treatment groups. The adjusted p ‐value for the comparison between osimertinib alone and osimertinib combined with mAb197 is 0.0044. All experiments were repeated at least twice.

Article Snippet: GAS6 , 67202 , Cell Signaling Technology (CST) , AB_2799720.

Techniques: Blocking Assay, Animal Model, Knock-Out, Generated, 96 Well Plates, Staining, Colorimetric Assay, Injection, Analysis, Comparison

Journal: Advanced Science

Article Title: Fc‐Dependent Targeting of the GAS6–MERTK Axis With Monoclonal and Bispecific Antibodies Overcomes Drug Resistance Across EGFR Mutations in Exons 19, 20, and 21

doi: 10.1002/advs.78290

Figure Lengend Snippet: Dual blockade of EGFR and MERTK using antibodies delays tumor relapses, likely due to the ability of EGFR to interact with MERTK within membrane microdomains. (A, B) CD1‐nu/nu mice were subcutaneously implanted with PC9 cells (2.5 × 10 6 ). Once tumors became palpable, animals (5–7 per group) were randomized and treated twice weekly for 4 weeks with the indicated mAbs (200 µg/injection, intraperitoneally), and/or daily with osimertinib (5 mg/kg; orally). Tumor volumes were measured twice weekly. Tumor volumes on day 47 are shown as mean ± SEM. Statistical significance was determined using an unpaired t ‐test; * , p < 0.05. Tumor volumes and animal survival are shown. The grey‐shaded area indicates the treatment period. Data are presented as tumor volume (mean ± SEM; A) and the corresponding Kaplan–Meier survival curves (B). (C and D) PC9 and H1975 cells (3 × 10 3 ) were seeded in 96‐well plates. The next day, cells were treated for 3 days with different concentrations of osimertinib and MRX‐2843 in pairwise combinations. Following fixation, cells were stained with crystal violet to identify viable cells. The synergy scores of the drugs were calculated based on the Bliss reference model, using SynergyFinder. The red color indicates high synergy scores, implying cooperative EGFR‐MERTK interactions. (E) PC9 cells (1 × 10 4 ) were seeded on coverslips and allowed to adhere overnight. The next day, cells were serum starved for 6 h and treated with either EGF (100 ng/mL) or GAS6 (250 ng/mL) in serum‐free medium. Thereafter, the cells were fixed, permeabilized, and then stained with a rabbit anti‐MERTK antibody, as well as with a murine anti‐human EGFR antibody. Subsequently, a proximity ligation assay was performed using anti‐Rabbit Plus and anti‐Mouse Minus. The amplified product of the PLA test was labeled using a red dye, and nuclei were stained with DAPI. Images were obtained using a Zeiss Spinning Disk confocal microscope, and the analysis was performed using ImageJ. MERTK knockout PC9 cells were used as a negative control. Scale bar, 10 µm. All experiments were repeated twice. (F) PC9 cells were seeded on glass coverslips and serum‐starved for 8 h, followed by stimulation for 60 min with either EGF (100 ng/mL) or Gas6 (250 ng/mL). Cells were then fixed and immunostained for EGFR (green) and nuclear DNA (DAPI; blue) and caveolin‐1 (red). Colocalization of EGFR with caveolin‐1 is indicated by white arrows. Scale bar, 5 µm.

Article Snippet: GAS6 , 67202 , Cell Signaling Technology (CST) , AB_2799720.

Techniques: Membrane, Injection, 96 Well Plates, Staining, Proximity Ligation Assay, Amplification, Labeling, Spinning Disk, Confocal, Microscopy, Analysis, Knock-Out, Negative Control, Glass

Journal: Advanced Science

Article Title: Fc‐Dependent Targeting of the GAS6–MERTK Axis With Monoclonal and Bispecific Antibodies Overcomes Drug Resistance Across EGFR Mutations in Exons 19, 20, and 21

doi: 10.1002/advs.78290

Figure Lengend Snippet:

Article Snippet: GAS6 , 67202 , Cell Signaling Technology (CST) , AB_2799720.

Techniques: Cell-Signaling