p38 mapk inhibitor sb203580  (MedChemExpress)

Journal: bioRxiv

Article Title: An APP-centered molecular gateway integrates innate immunity and retinoic acid signaling to drive irreversible metamorphic commitment

doi: 10.64898/2026.01.22.700939

Figure Lengend Snippet: (A) Settlement rate of inhibitor-treated larvae. The box plots with superimposed jitter plots display the larval settlement rate under various inhibitor treatments. The biofilm stimulus condition is used as the positive control. The concentration of each inhibitor is indicated on the horizontal axis. The data represent the settlement rate of larvae remaining attached out of 10 larvae across six independent biological replicates (total n = 60). Statistical significance among treatment groups was assessed using one-way ANOVA followed by Tukey’s HSD post hoc test, with grouping letters indicating significant differences ( p < 0.05); treatments sharing a letter are not significantly different. (B) Quantitative assessment of the functional hierarchy. The box plots with superimposed jitter plots show the Metamorphic Progression Scores (MPS) for larvae treated with various pharmacological inhibitors with or without all-trans retinoic acid (RA). The MPS was calculated based on the metamorphic stage reached by the larvae in the identical assays used for the settlement rate analysis in (A). The concentration of each inhibitor is indicated on the horizontal axis. The MPS represents the average metamorphic stage reached (0 = brachiolaria; 1 = early; 2 = middle; 3 = late; 4 = pre-juvenile; 5 = juvenile). Statistical significance among the treatment groups was assessed using one-way ANOVA followed by Tukey’s HSD post hoc test ( *p < 0.05; n.s., not significant). A significant RA-dependent rescue condition (a statistically significant increase in MPS compared with the inhibitor-alone condition) is highlighted in grey, establishing the functional hierarchy of the pathways relative to the RA commitment signal. (C) Representative image illustrating pathway functional hierarchy. Images show representative larval morphology under the control, inhibitor-only, and inhibitor + RA conditions. These images specifically represent the high-concentration inhibitor treatments (MyD88 inhibitor: 50 µM; MAPK inhibitors: 10 µM; IKKβ and HSP90AA1 inhibitors: 1 µM). MyD88 inhibition completely blocks the behavioral decision of settlement. JNK and p38 inhibition caused a distinct early-stage arrest (low MPS), and the effects of their inhibition were significantly rescued by RA co-treatment. In contrast, ERK inhibition arrested metamorphosis at the middle stage, and this block was not rescued by exogenous RA. Similarly, IKKβ and HSP90AA1 inhibition arrested metamorphosis at later stages, and this block was not rescued by exogenous RA, functionally placing all three pathways (ERK, IKKβ, and HSP90AA1) downstream of the RA commitment signal. Scale bar: 200 µm. Inhibitors used: T6167923 (MyD88 inhibitor), IKK-16 (IKKβ inhibitor), U0126 (ERK inhibitor), SP600125 (JNK inhibitor), SB202190 (p38 inhibitor), and Luminespib (HSP90AA1 inhibitor).

Article Snippet: The inhibitors were dissolved in DMSO and applied at the indicated concentrations: the MyD88 inhibitor T6167923 (5 or 50 μM; MedChemExpress), the IKKβ inhibitor IKK-16 (0.1 or 1 μM; MedChemExpress), and MAPK inhibitors SP600125 (JNK), SB202190 (p38), and U0126 (ERK) (1 or 10 μM; MedChemExpress or FUJIFILM Wako Pure Chemical Corporation), and the HSP90AA1 inhibitors luminespib (0.1 or 1 μM; Chemscene).

Techniques: Positive Control, Concentration Assay, Functional Assay, Control, Inhibition, Blocking Assay

Journal: bioRxiv

Article Title: An APP-centered molecular gateway integrates innate immunity and retinoic acid signaling to drive irreversible metamorphic commitment

doi: 10.64898/2026.01.22.700939

Figure Lengend Snippet: This model illustrates the proposed three-tiered molecular switch that translates external microbial cues into the irreversible developmental fate of sea star metamorphosis, based on Dynamic Network Module (DNM) analysis and comprehensive pharmacological functional assays. This cascade integrates innate immune and developmental signaling pathways across three functional layers: Signal Sensing, Commitment Conversion, and Irreversible Execution. The process is initiated in the Signal Sensing layer, where the environmental cue, microbial biofilms, activates the adapter protein MyD88, which serves as an obligatory first-tier hub. MyD88 transmits signals via the JNK/p38/ERK MAPK pathway to govern the initial settlement behavior. MyD88 exhibits a concentration-dependent dual output: high-dose inhibition abolishes settlement behavior (RA-non-rescuable), while low-dose inhibition permits settlement but causes a late-stage molecular arrest (RA-non-rescuable). Following sensing, the cascade enters the Commitment Conversion layer. JNK/p38 MAPK acts as an essential hybrid adapter that converts immune signals into a Retinoic Acid (RA) hormonal commitment signal (RA-rescuable phenotype). The Amyloid Precursor Protein (APP) functions as the irrevocable commitment gateway, integrating inputs from the upstream MAPK, IKKβ/NFκB, and RA signaling axes to make the final molecular decision. APP ensures irreversibility through “signal focusing,” maintaining its signal strength during the systemic “mass shutdown” of non-essential larval programs. The process culminates in an Irreversible Execution Tier, where the robust execution of the metamorphic program relies on the multi-layered convergence of signals onto the master transcription factor, TFAP2A. The APP commitment decision is translated into transcriptional output via the release of its intracellular domain (AICD), which acts as the final dedicated execution switch by converging to TFAP2A in complex with GSK3β/Src. TFAP2A receives parallel inputs from RA (for launching the program), IKKβ/NFκB (for sustained maintenance and transcriptional output; RA non-rescuable), and ERK (a crucial early execution factor for immediate morphogenesis and physical attachment maintenance; RA non-rescuable). Finally, the RA signal induces the HSP90AA1 chaperone, establishing a positive feedback loop that maintains the structural integrity and function of critical signaling complexes (including MyD88 and APP), thereby ensuring the stability of the executed program.

Article Snippet: The inhibitors were dissolved in DMSO and applied at the indicated concentrations: the MyD88 inhibitor T6167923 (5 or 50 μM; MedChemExpress), the IKKβ inhibitor IKK-16 (0.1 or 1 μM; MedChemExpress), and MAPK inhibitors SP600125 (JNK), SB202190 (p38), and U0126 (ERK) (1 or 10 μM; MedChemExpress or FUJIFILM Wako Pure Chemical Corporation), and the HSP90AA1 inhibitors luminespib (0.1 or 1 μM; Chemscene).

Techniques: Functional Assay, Protein-Protein interactions, Concentration Assay, Inhibition

Journal: Cellular and Molecular Gastroenterology and Hepatology

Article Title: Liver Sinusoidal Endothelial Cells Promote Metabolic Dysfunction-associated Steatohepatitis Progression via Interleukin-1R1-mediated Chemokine Production Induced by Macrophage-derived Interleukin-1β

doi: 10.1016/j.jcmgh.2025.101698

Figure Lengend Snippet: Increased IL-1β secretion by macrophages due to autophagy impairment enhances inflammatory chemokine expression in LSECs. ( A ) Protein expression in ATG7-KO macrophages and NC macrophages generated using the CRISPR-CAS9 system. ( B ) Evaluation of IL-1β and caspase-1 levels in the culture supernatant of THP-1 macrophages by ELISA following 24-hour stimulation with or without 25 ng/mL LPS (n = 3/group). ( C ) Experimental method using LPS-stimulated THP-1 macrophage conditioned medium. ( D ) Evaluation of NF-κB or MAP kinase-related proteins in TMNK-1 cells. ( E and F ) Inflammatory chemokine gene expression in TMNK-1 cells when treated with control medium or THP-1 macrophage conditioned medium (n = 4/group). SN50, NF-κB inhibitor; SP600125, JNK inhibitor; SB203580, p38 MAPK inhibitor. ( G ) Inflammatory chemokine gene expression measured 24 hours after treating TMNK-1 cells with varying concentrations of human recombinant IL-1β (n = 4/group). ( H ) Evaluation of inflammatory chemokine expression in TMNK-1 cells after 6 hours of stimulation with recombinant human IL-1β (5 ng/mL) in the presence of SP600125 and SB203580 (n = 4/group).

Article Snippet: The inhibitors used were as follows: the NF-κB inhibitor SN50 (HY-P0151; MedChemExpress), the JNK inhibitor SP600125 (HY-12041; MedChemExpress), the p38 MAPK inhibitor SB 203580 (HY-10256; MedChemExpress), and the IL-1R antagonist (IL-1Ra) (093-05991; FUJIFILM Wako Pure Chemical Corporation).

Techniques: Expressing, Generated, CRISPR, Enzyme-linked Immunosorbent Assay, Gene Expression, Control, Recombinant

Journal: Cellular and Molecular Gastroenterology and Hepatology

Article Title: Liver Sinusoidal Endothelial Cells Promote Metabolic Dysfunction-associated Steatohepatitis Progression via Interleukin-1R1-mediated Chemokine Production Induced by Macrophage-derived Interleukin-1β

doi: 10.1016/j.jcmgh.2025.101698

Figure Lengend Snippet: Macrophage-derived IL-1β increases CCL2 expression in HSCs via JNK activation. ( A ) Evaluation of the levels of NF-κB or MAPK-related proteins in LX-2 cells. ( B, C ) CCL2 gene expression in LX-2 cells treated with the control medium or THP-1 macrophage conditioned medium (n = 3/group). SN50, NF-κB inhibitor; SP600125, JNK inhibitor; SB203580, p38 MAPK inhibitor. ( D ) Evaluation of CCL2 expression in TMNK-1 cells after 48 hours of stimulation with recombinant human IL-1β (5 ng/mL) in the presence of SP600125 and SB203580 (n = 4/group).

Article Snippet: The inhibitors used were as follows: the NF-κB inhibitor SN50 (HY-P0151; MedChemExpress), the JNK inhibitor SP600125 (HY-12041; MedChemExpress), the p38 MAPK inhibitor SB 203580 (HY-10256; MedChemExpress), and the IL-1R antagonist (IL-1Ra) (093-05991; FUJIFILM Wako Pure Chemical Corporation).

Techniques: Derivative Assay, Expressing, Activation Assay, Gene Expression, Control, Recombinant

Journal: The FASEB Journal

Article Title: LncRNA DANCR Activates p38/ mTOR ‐Mediated Autophagy via ANXA2 to Exacerbate Oxygen‐Induced Retinal Neovascularization in Mice

doi: 10.1096/fj.202502408R

Figure Lengend Snippet: DANCR induced autophagy through the ANXA2‐mediated p38/mTOR axis, thereby enhancing the angiogenic potential of ECs. (A) The autophagy‐related protein expression of LC3B and P62 was quantified through a western blot assay ( n = 4). The normality of data distribution and variance homogeneity were assessed by the Shapiro–Wilk test, the corrected Bartlett's test, and the one‐way ANOVA test with Tukey's multiple comparisons test. (B) The protein expression of ANXA2 was quantified through a western blot assay ( n = 4). Kruskal–Wallis test followed by Dunn's multiple comparisons post hoc analysis. (C) VEGF secretion was measured by ELISA ( n = 6). One‐way ANOVA with Tukey's multiple comparisons post hoc analysis. (D) Tube‐formation ability was measured through a Matrigel angiogenesis assay in ECs. Quantifying the branch point (E) and tube length (F). One‐way ANOVA with Tukey's multiple comparisons post hoc analysis. Scale bar: 500 μm. Data are shown as means ± SD of 6 independent experiments. (G) The protein expression of p‐p38 MAPK and p‐mTOR was quantified through a western blot assay ( n = 3). One‐way ANOVA with Tukey's multiple comparisons post hoc analysis. (H–K) A western blot assay quantified the expression of p‐HSP27, HSP27, ANXA2, Beclin‐1, and P62 ( n = 4). One‐way ANOVA with Tukey's multiple comparisons post hoc analysis. (ns, p > 0.05; * p < 0.05; ** p < 0.01; *** p < 0.001).

Article Snippet: For the inhibition experiment, the autophagy inhibitor 3‐methyladenine (3‐MA, 5 mM, MCE, USA) and the p38 pathway inhibitor SB203580 (SB, 10 μM, MCE, USA) were applied, along with hypoxia exposure.

Techniques: Expressing, Western Blot, Enzyme-linked Immunosorbent Assay, Angiogenesis Assay

Journal: The FASEB Journal

Article Title: LncRNA DANCR Activates p38/ mTOR ‐Mediated Autophagy via ANXA2 to Exacerbate Oxygen‐Induced Retinal Neovascularization in Mice

doi: 10.1096/fj.202502408R

Figure Lengend Snippet: Schematic illustration of molecular mechanisms. The DANCR/ANXA2/p38 MAPK axis promotes ECs' tube formation ability by activating autophagy (the diagram was drawn by Figdraw).

Article Snippet: For the inhibition experiment, the autophagy inhibitor 3‐methyladenine (3‐MA, 5 mM, MCE, USA) and the p38 pathway inhibitor SB203580 (SB, 10 μM, MCE, USA) were applied, along with hypoxia exposure.

Techniques: