Sex and strain-specific changes of macrophage cytokine profile in female rats during reproductive aging

Starenje se povezuje sa razvojem sistemskog, sterilnog hroničnog zapaljenja (engl. „inflammaging”). Malo je podataka o uticaju genetskih faktora i pola na sposobnost makrofaga (Mϕ), kao ključnih ćelija urođenog imunskog odgovora, da tokom starenja “kontrolišu” rezoluciju akutnog zapaljenja i time razvoj hroničnog zapaljenja. Ciljevi ove disertacije su bili da se ispita 1) uticaj rane faze reproduktivnog starenja na fenotipske osobine (ekspresija markera povezanih sa aktivacijom i poreklom/funkcijom) i funkcijska svojstva (fagocitoza, sinteza inflamatornih medijatora) Mϕ “mirne” i inflamirane (delovanjem tioglikolata) peritonealne duplje ženki Albino Oxford (AO) pacova, 2) značaj genetskih faktora za reproduktivnim starenjem uslovljene promene peritonealnih Mϕ od značaja za uspešnu rezoluciju akutnog zapaljenja i 3) uloga polnih steroida u nastanku ovih promena uporednom analizom promena kod mužjaka i ženki AO pacova, njihovom analizom kod ženki AO pacova kojima su na kraju reproduktivnog perioda uklonjeni jajnici i ispitivanjem delovanja estradiola na Mϕ mladih i sredovečnih ženki AO pacova in vitro. Rezultati su pokazali da: 1) se sposobnost Mϕ ženki AO pacova da “kontrolišu” rezoluciju akutnog zapaljenja menja već tokom rane faze reproduktivnog starenja, kao i da su ove promene sojno specifične (Mϕ sredovečnih ženki AO pacova koje “uspešnije” stare od ženki Dark Agouti pacova pokazuju svojstva koja se mogu povezati sa boljom “kontrolom” inflamacije); 2) su ove promene polno specifične (Mϕ sredovečnih ženki imaju svojstva koja ukazuju na veći kapacitet da “kontrolišu” inflamaciju od Mϕ mužjaka istog uzrasta) i 3) u nastanku promena relevantnih za sposobnost Mϕ ženki AO pacova da “kontrolišu” akutnu inflamaciju važnu ulogu imaju promene u delovanju i estradiola i progesterona. Dodatno, ispitavanja in vitro su ukazala da su za uzrasno zavisne promene u sposobnosti Mϕ da “kontrolišu” inflamaciju pored promene u koncentraciji estradiola važne i one u samim Mϕ, koje menjaju njihov odgovor na delovanje estradiola.Aging is associated with the development of systemic, sterile chronic inflammation ("inflammaging"). Little is known about the influence of genetic factors and sex on the ability of macrophages (Mϕ), as key innate immune cells, to "control" the resolution of acute inflammation and thus the development of chronic inflammation during aging. The objectives of this dissertation were to examine 1) the influence of the early phase of reproductive aging on phenotypic characteristics (expression of markers associated with activation and origin/function) and functional characteristics (phagocytosis, synthesis of inflammatory mediators) of Mϕ isolated from “naive” and inflamed (thioglycollate-induced) peritoneal cavity of females Albino Oxford (AO) rats; 2) the significance of genetic factors for reproductive aging-related changes of peritoneal Mϕ, especially those important for successful resolution of acute inflammation and 3) the role of sex steroids in the occurrence of these changes by comparative analysis in males and females of AO rats, their analysis in female AO rats whose ovaries were removed at the end of the reproductive period and by examining in vitro effect of estradiol on Mϕ from young and middle-aged female AO rats. The results showed that: 1) the ability of Mϕ from AO females to “control” the resolution of acute inflammation changes during the early phase of reproductive aging, and these changes are strain-specific (Mϕ from middle-aged AO females that “age more successful” than Dark Agouti females, show properties which may be associated with better "control" of inflammation); 2) these changes are sex-specific (Mϕ from middle-aged females have a greater capacity to “control” inflammation than Mϕ from males of the same age group) and 3) both estradiol and progesterone play important roles in the ability of Mϕ from AO females to “control” acute inflammation. In vitro studies revealed that, in addition to changes in estradiol concentration, intrinsic changes in Mϕ that regulate their response to estradiol action are important for agedependent changes in Mϕ ability to „control“ inflammation

Aging affects the responsiveness of rat peritoneal macrophages to GM-CSF and IL-4

Macrophages undergo significant functional alterations during aging. The aim of the present study was to investigate changes of rat macrophage functions and response to M1/M2 polarization signals with age. Therefore, resident and thioglycollate-elicited peritoneal macrophages from young (3-month-old) and aged (18-19-month-old) rats were tested for phagocytic capacity and ability to secrete inflammatory mediators following in vitro stimulation with LPS and GM-CSF, and IL-4, prototypic stimulators for classically (M1) and alternatively activated (M2) macrophages, respectively. Aging increased the frequency of monocyte-derived (CCR7+ CD68+) and the most mature (CD163+ CD68+) macrophages within resident and thioglycollate-elicited peritoneal macrophages, respectively. The ability to phagocyte zymosan of none of these two cell subsets was affected by either LPS and GM-CSF or IL-4. The upregulated production of IL-1 beta, IL-6 and IL-10 and downregulated that of TGF-beta was observed in response to LPS in resident and thioglycollate-elicited macrophages from rats of both ages. GM-CSF elevated production of IL-1 beta and IL-6 in resident macrophages from aged rats and in thioglycollate-elicited macrophages from young rats. Unexpectedly, IL-4 augmented production of proinflammatory mediators, IL-1 beta and IL-6, in resident macrophages from aged rats. In both resident and thioglycollate-elicited macrophages aging decreased NO/urea ratio, whereas LPS but not GM-SCF, shifted this ratio toward NO in the macrophages from animals of both ages. Conversely, IL-4 reduced NO/urea ratio in resident and thioglycollate-elicited macrophages from young rats only. In conclusion, our study showed that aging diminished GM-CSF-triggered polarization of elicited macrophages and caused paradoxical IL-4-driven polarization of resident macrophages toward proinflammatory M1 phenotype. This age-related deregulation of macrophage inflammatory mediator secretion and phagocytosis in response to M1/M2 activators may lead to the deficient control of infectious and/or inflammatory diseases in advanced age