Journal: iScience

Article Title: Serum SOS1 as a prognostic biomarker and therapeutic target for progressive liver disease

doi: 10.1016/j.isci.2026.116430

Figure Lengend Snippet: SOS1 inhibition attenuates extracellular matrix deposition, stellate cell activation, and downstream signaling in LX2 hepatic stellate cells (A–D) Decellularized extracellular matrix (ECM) derived from activated LX2 cells treated with increasing concentrations of SOS1 inhibitor (SOS-I) and stained with NHS-Fluorescein, showing a progressive reduction in ECM deposition with SOS1 inhibition. (E) Representative immunoblot of fibrogenic markers (COL1A1, FN1, α-SMA, PDGFRB) with calnexin as loading control, demonstrating reduced protein expression following SOS-I treatment. (F–I) Quantitative analyses of fibrogenic and inflammatory readouts showing modulation of ECM-associated and signaling markers following SOS1 inhibition. (J–M) Immunofluorescence staining of extracellular matrix components, including collagen (green, J and K) and fibronectin (red, L and M), demonstrating reduced matrix deposition in SOS-I-treated cells. Nuclei are counterstained with DAPI (blue). (N and O) BODIPY staining of LX2 cells showing increased lipid droplet accumulation following SOS1 inhibition, consistent with partial reversion of stellate cell activation. (P and Q) Transwell migration assays demonstrating reduced migratory capacity of activated LX2 cells following SOS-I treatment. (R) Immunoblot analysis of pERK and total ERK in LX2 cells stimulated with PDGFB in the presence or absence of SOS-I, with calnexin as loading control, showing attenuation of PDGFB-induced ERK phosphorylation. (S) Immunoblot analysis of pERK and total ERK in LX2 cells treated with increasing concentrations of SOS-I, demonstrating dose-dependent reduction in ERK phosphorylation. (T) qRT-PCR confirmation of siRNA-mediated SOS1 knockdown using two independent siRNAs (13.1 and 13.2), with expression normalized to GAPDH. (U) Immunoblot analysis showing the effect of SOS1 knockdown on COL1A1 and IL-1β protein expression, with calnexin as loading control. Data are presented as mean ± SEM with individual data points shown. Statistical significance is indicated as ∗ p < 0.05, ∗∗ p < 0.01. Statistical analyses were performed using one-way ANOVA with Tukey’s post hoc test or two-tailed unpaired Student’s t test where appropriate. Data represent mean ± SEM from n = 3 independent experiments (LX-2 studies). Exact p values are shown in the graphs. Scale bars, 400 μm for ECM imaging in (A–D); 200 μm for extracellular collagen and fibronectin immunofluorescence images (J–M) and BODIPY staining (N and O); and 100 μm for transwell migration assay images (P and Q).

Article Snippet: NHS-Fluorescein , ThermoFisher , Catalog # 46409.

Techniques: Inhibition, Activation Assay, Derivative Assay, Staining, Western Blot, Control, Expressing, Immunofluorescence, Migration, Phospho-proteomics, Quantitative RT-PCR, Knockdown, Two Tailed Test, Imaging, Transwell Migration Assay