Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A) Plasma substance P levels in SCD patients were higher during hospitalization for VOC (n=71) than at steady sate (n=132) with further increase during ACS (n=30). Horizontal line is the 99 th percentile in the general population. (B-C) Plasma substance P levels were increased in SS mice but not in AA mice after hypoxia/reoxygenation (H/R) or hemin injection (70 µmol/kg i.v.). *** P <0.001. ** P <0.01.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Clinical Proteomics, Injection

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A) Substance P injection (40 mg/kg i.v.) caused painful crises in all SS mice (n=7) but no AA mice (n=7), leading to death in the majority of SS mice (n=6/7). (B) Lethality induced by substance P was dose dependent. (C) Substance P injection was responsible for acute lung injuries with congestion, edema, alveolar wall thickening and hemorrhage. (D) Lung injury score was significantly higher in SS mice than in AA mice, with further increase after substance P injection. *** P <0.001. ** P <0.01.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Injection

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: MAR-1 (anti-Fc ε R1 α ) induces lethal crises and acute lung injuries in SS mice whereas cromolyn prevents lung injuries induced by substance P. (A) MAR-1 injection (10 µg/kg i.p.) caused painful crises in all SS mice (n=7) but no AA mice (n=7), leading to death in the majority of SS mice (n=5/7). (B) Lung injuries induced by MAR-1 were similar to those induced by substance P, with increased congestion, edema, alveolar wall thickening and hemorrhage. (C-D) Lung injuries induced by substance P (12 mg/kg i.v.) in SS mice (n=4) were significantly reduced by pretreatment with cromolyn (10 mg/kg/d i.p., n=4) for four days. ** P <0.01. * P <0.05.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Injection

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A-C) Blood basophil counts from SS mice were higher compared to AA mice and decreased during VOC/ACS induced by H/R, hemin or substance P. (D) fluorescent immunohistochemistry on the lungs of SS and AA mice injected with substance P (12 mg/kg i.v.) revealed the presence of FcεR1α + cells (stained in red; nuclei stained in blue by DAPI) at baseline in the lungs of SS mice but not AA mice, with further increase after substance P injection in SS mice. This effect was abrogated in mice that were pretreated with cromolyn, suggesting a role for mast cell/basophil degranulation in promoting basophil recruitment to the lungs. *** P <0.001. ** P <0.01.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Immunohistochemistry, Injection, Staining

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A) Immunohistochemistry revealed a high number of both mast cells (stained by anti-FcεRIα (MAR-1) and anti-c-kit primary antibodies) and basophils (stained by anti-FcεRIα (MAR-1) and anti-Mcpt-8 primary antibodies) in the lungs of SS mice, but not in AA mice. (B-C) In vitro, incubation of murine bone marrow derived mast cells (B) and basophils (C) with avidin (5µg/ml) and substance P (10 -6 M) was responsible for a significant increase in avidin+ cells measured by flow cytometry, reflecting increased degranulation. *** P <0.001. * P <0.05.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Immunohistochemistry, Staining, In Vitro, Incubation, Derivative Assay, Avidin-Biotin Assay, Flow Cytometry

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A-B) Substance P levels, and to a lesser degree histamine levels, were higher in the sputum from SCD patients during ACS (n=7) than in the sputum from SCD patients (n=4) and age-matched controls (n=6) during pneumonia. (C) In vitro, substance P had a chemoattractant effect on murine bone marrow-derived basophils, which was abrogated by NK1R antagonist. LPS was used as a positive control and histamine was also confirmed to be a potent chemoattractant for basophils. *** P <0.001. ** P <0.01. * P <0.05.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: In Vitro, Derivative Assay, Positive Control

Journal: medRxiv

Article Title: Substance P, mast cells and basophils are involved in acute chest syndrome in sickle cell disease

doi: 10.64898/2026.03.02.26347450

Figure Lengend Snippet: (A-C) Gene expression of CCR2, CCR3 and FPR1 was increased in blood basophils from SCD patients isolated by flow cytometry sorting (at steady state (n=5), during a MET program (n=5), during a VOC (n=5) or at the end of a VOC (n=5)) compared to age-matched healthy controls (n=5). (D-F) Subsequently, spectral flow cytometry on blood samples from off-crisis SCD patients (n=10) and age-matched healthy controls (n=5) revealed increased basophil surface expression of CCR3 and FPR1 compared to controls. (G-H) The two substance P receptors, NK1R and MRGPRX2 were also overexpressed. (I) Basophil count was higher in SCD patients than in controls. ** P <0.01. * P <0.05.

Article Snippet: Substance P (Tocris Bioscience) was prepared by dissolving in PBS and was used immediately.

Techniques: Gene Expression, Isolation, Flow Cytometry, Expressing