Inflammatory factors associated with stress and old age are not observed in steady-state MA female mice. (A) GSEA of a hallmark inflammatory response signature in young and MA MSC-Adipo-1, MSC-Adipo-2, MSC-Osteo, EC-Arteriolar, and EC-Sinusoidal (SEC) cell clusters. (B) Differential expression of Il1b, Ccl6, Ccl5, Il6, Tnf, C4b, Cfb, and C3 in MA vs young MSC-Adipo-1, MSC-Adipo-2, MSC-Osteo, EC-Sinusoidal (SEC), and EC-Arteriolar (AEC) cell clusters, old (2 years) vs young MSC (CARc) and SECs∗, and young LPS-treated or polyI:C (pI:C)-treated vs young MSC (CARc) and SECs∗. ∗Derived from published data.⁴⁸ (C) Heat map representing differential expression of Il1b, Ccl6, Ccl5, Il6, Tnf, Ifng, C4b, Cfb, and C3 in all MA vs young cell clusters. (D) Relative protein level of IL-1α, RANTES, IL-6, TNF, IFN-γ, IL-2, IL-3, IL-4, and IL-7 in BM fluid from young (2 months) and MA (12-14 months) mice. Bars represent mean ± standard error of the mean of n = 5-8 per condition. P values were calculated using 2-way analysis of variance with Sidak multiple comparisons test. ∗∗∗∗P < .0001. (E) Experimental design to analyze CM from Igf1^–/– and control MSCs. (F) Concentration of IL-1α, IL-1β, IL-6, IFN-γ, and IL-7 in CM from young control (2 months) and Igf1^–/– MSCs. Each dot represents 1 biological replicate. (G) Correlation between Il1b, Ccl5, Il6, and Tnf expression in Adipo-MSC-1 and differentiation-inactive HSC signature in individual MA mice. Each dot represents 1 mouse. (H) Correlation between Il1b, Ccl5, Il6, and Tnf expression in Adipo-MSC-1 and lymphoid progenitor signatures and genes in HSCs in individual MA mice. Each dot represents 1 mouse. WT, wild type.