Toniolo, Alice (2014) Polarization in patterns of human monocyte-derived macrophages in relation to estrogen treatment and menopausal status. [Tesi di dottorato]
Full text disponibile come:
Mononuclear phagocytes respond to environmental cues with the acquisition of distinct functional phenotypes, M1 (classical) or M2 (alternative), which in turn are involved in different pathological conditions. 17β-estradiol (E2), the major female sex hormone, is known to mediate profound effects on monocyte and macrophage immune function acting through estrogen receptors (ER). We hypothesized that estrogen-dependent effects on the monocyte/macrophage system protect postmenopausal women from cardiovascular disease. To test our hypothesis, we first investigated the effects of E2 on human monocyte-derived macrophage subsets in resting state (M0) and after M1 or M2 polarized activation. Human monocytes were isolated from buffy coats by density gradient centrifugation and monocyte-to-macrophage differentiation occurred within 7 days in the absence of any stimulating factors other than serum. We demonstrated that spontaneously differentiated human macrophages polarized to M1/M2 phenotypes by 48h-stimulation with LPS/IFN-γ or IL-4/IL-13, respectively. Polarized macrophages showed specific gene expression profiles different cytokine production (TNFα, IL-1β, IL-10, CCL22) and surface markers. In particular, the M1 phenotype was characterized by flow cytometry as percentage of CD68+, CD68+/CCR2+, CD14+/CD16-/CD68+ or CD80+ cells and the M2 phenotype was identified as CD163+, CD206+, CX3CR1+ cells. We also demonstrated that M1 activation with LPS/IFN-γ down-regulated the M2 immunophenotype. Similarly to dexamethasone, used as a reference drug, E2 promoted a M2 macrophage signature counteracting the negative regulation by pro-inflammatory stimuli of both M2 surface marker expression and cytokine production. Overall, these data suggest that differences in the functional status of macrophages are critical to investigate pharmacological macrophage targeting. Given that the pro-inflammatory activity of monocyte-macrophages plays a role in the development and progression of CVD, we subsequently investigated if an imbalance in the M1/M2 ratio of macrophages derived from peripheral blood monocytes menopausal women could be detected in relation to menopausal status. In the resting state, macrophages from post-menopausal women displayed similar M1/M2 phenotype with respect to macrophages from pre-menopausal women. However, among post-menopausal women, the M2 phenotype was enhanced and M1 was attenuated by ongoing statin therapy with respect to non statin-treated patients. Moreover, macrophages from post-menopausal women after polarized activation displayed similar M1 response but impaired alternative activation (M2) with respect to those from pre-menopausal women. In the attempt to identify a biomarker linking menopause to cardiovascular risk, the M1/M2 ratio in circulating monocytes from pre- and post-menopausal women was measured and found unchanged. In conclusion, estrogenic pathways modulate the phenotypes and function of human macrophages and represent a possible pharmacological intervention in inflammatory disease. Future perspectives include investigating monocyte-macrophage polarization in women in relation to menstrual cycle and endocrine disease such as polycystic ovary syndrome.
Statistiche Download - Aggiungi a RefWorks
I fagociti mononucleari rispondono a stimoli ambientali acquisendo distinti fenotipi funzionali, definiti M1 (classico) o M2 (alternativo), che caratterizzano a loro volta differenti condizioni patologiche. Il 17β-estradiolo (E2), il principale ormone del sistema riproduttivo femminile, media molteplici effetti sulla funzione immunitaria di monociti e macrofagi, agendo attraverso i recettori per gli estrogeni (ER). Ipotizziamo, dunque, che gli effetti dipendenti dagli estrogeni a carico del sistema monocito-macrofagico proteggano la donna in post-menopausa da disturbi cardiovascolari, ed, in particolare, che l’aggravarsi del rischio cardiometabolico nelle donne in post-menopausa sia associato ad uno shift della popolazione monocito-macrofagica verso un fenotipo infiammatorio. Pertanto, in questa tesi abbiamo investigato gli effetti dell’E2 su macrofagi derivanti da monociti umani in condizioni basali (M0) ed in seguito ad attivazione polarizzata classica/M1 o alternativa/M2.
Solo per lo Staff dell Archivio: Modifica questo record