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The systemic and extra- gonadal levels of 17 beta-estradiol (E2) change during aging, and affect the expression of estrogen receptors (ERs) in the immune cells of both females and males. The age-related cessation of ovarian function in females, as well as the tissue-specific expression of enzyme aromatase (estrogen synthase which significantly rises with the advancing age) in both males and females, both determine the concentration of E2 to which immune cells may be exposed. The present study was set up to investigate the direct influence of E2 in vitro on the secretory profile of peritoneal macrophages from young and naturally menopausal female rats, and from young and middle-aged male rats. The involvement of receptor(s) responsible for mediating the effects of E2 in vitro was examined by use of antagonists specific for ERa or ER beta. Whereas in macrophages from young female rats E2 treatment diminished interleukin (IL)-1 beta secretion, it increased it in young males, and the middleaged females. The in vitro E2 treatment increased tumor necrosis factor (TNF)-alpha release by macrophages from young rats of both sexes, while it increased macrophage IL-6 release independently of both sex and age. At the same time, E2 decreased hydrogen peroxide (H2O2) production in macrophages from females, and increased it in male rats of both ages, whereas it diminished nitric oxide (NO) release in all experimental groups. Inspite of the sex-and age-specific effects of E2 on macrophage urea release, E2 did not affect the NO/urea ratio in macrophages from female rats, and diminished it in macrophages from both young and middle-aged male rats. Independently of the sex and age, E2 stimulated the release of inflammatory cytokines predominantly via macrophage ER alpha, and inhibited the IL-1 beta release in young females via ER beta. In contrast, E2 increased macrophage H2O2 and urea production by activating ER beta, but diminished their release via ER alpha. Our study may contribute

Cilj rada bio je da se ispita uticaj starenja na aktivnost makrofaga aktivisanih M1/M2 polarizujućim faktorima. Peritonealne rezidentne makrofage (rMf) i tioglikolatom“ indukovane makrofage (pMf) mladih (3 mesoca) im starih (18-19 meseci) pocova su kultivisane u prisustvu stimulatora klasične (M1) - lipopolisaharida (LPS) i faktora stimulacije kolonija granulocita i makrofaga (GM-CSF), i alternativis (M2) aktivacije makrofaga - ingerleukina-4 (IL-4), ili u odsustvu poznatih stimulatora. Ispitivana je sposobnost fagocitoze zimozana i sekrecije inflamatornih medijlora. Starsnjem se povećavala učestalost makrofaga monoci:nog porekla (SSK7'S068' ćelije) u okviru populacije rMf, dok je u okviru populacije tMf nađena povećana učestalost makrofaga najzrelijeg fenotipa (CD163'°CD68" ćelije). Nijedan od ispitivanih stimulatora nije uticao na fagocitnu sposobnost rMf i ztimf Povećana sekrecija IL-1D, 1:-6 i #10 i smanjena sekrecija IGF-D u odgovoru na stimulaciju LPS-om je nađena kod rMf i Md pacova obe starosti. GM-CSF je povećao sekreciju IL-1B i IL-6 kod rMf starih pacova i tMf mladih pacova. Paradoksalno, IL-4 je povećao sekreciju pro-inflamatornih citokina, IL-16 i IL-6, kod rMf starih pacova. Starenjem se metabolizam arginina i u rMf i u tgMf usmeravao ka sintezi ypee LPS je, za razliku od GM-CSF, favorizovao sintezu azot monoksida u rMf i pMf pacova obe starosti. Nasuprot tome, kod rRMf i pMf mladih pacova IL-4 je usmerio metabolizam arginina prema sintezi uree. Rezultati su pokazali da sa starenjem nM gube sposobnost polarizacije pod uticajem GM-CSF, i da rMf pod uticajom IL-4 polarizuju prema pro-inflamatornom Mi sekretornom fenotipu. Gubitak kontrole sekrecije inflamatornih medijatora iz makrofaga u odgovoru na M1/M2 aktivatore mogao bi da doprinese povećanom riziku od oboljevanja od infektivnih i inflamatornih bolesti u starosti.

Smanjena imunološka funkcija kod žena u menopauzi je uglavnom posledica nedostatka hormona ovarijuma u cirkulaciji. Supstituciona hormonska terapija najčešće podrazumeva nadoknadu estrogena, zli ne i progesterona. U ovom radu kao eksperimentalni model izolovane _ deficijencije _ progesterona _ korišćeni su pacovi stari 20 meseci ovarijektomisani na kraju reproduktivnog perioda (starosti 10 meseci) kod kojih je koncentracija estradiola (usled ekstragonadne sinteze) u nivou estradiola kod lažno ovarijektomisanih pacova iste starosti. Ispitivana je intraćelijska ekspresija receptora za estrogene (ER) i progesteron (PR) i sekrecija pro- i anti-inflamatornih citokina i krajnjih produkata metabolozma arginina u slezinskim i peritonealnim makrofagama, u bazalnim uslovima i nakon /" vitro stimulacije sa lipopolisaharidom (LPS). Pokazano je da i peritonealne i slezinske makrofage ispoljavaju ERa i ERV, kao i da oparijsktomija ne utiče na ekspresiju ER-a. Većina peritonealnih i slezinskih makrofaga je ispoljavala PR, a ovarijektomija je dovela do povećanja skspresije PR samo u slezinskim makrofagama. Ovarijektomija je smanjila sekreciju citokina iz slezinskih (IL-18) i peritonealnih makrofaga (TNF-a, [1-18, IL-10) i povećala sekreciju ||-10 iz slezinskih i TGE-B iz peritonealnih makrofaga u bazalnim uslovima. Nakon stimulacije LPS-om, slezinske makrofage ovarijektomisanih pacova su sekretovale manje TME-a i više IL-10, dok su peritoneale makrofage sekretovale manje IL-1B i TBR- nego ćelije istog porekla iz lažno. ovarijektomisanih pacova. Ovarijsktomija je smanjila sintezu uree i u slezinskim i u peritonealnih makrofagama stimulisanim LPS-om. Dugotrajna izolovana Doficijencija progesterona u post"reproduktivnom periodu narušava ravnotežu u produkciji pro-/anti- | inflamatornih citokina slezinskih i peritonsalnih makrofaga.

Rats of Albino Oxford (AO) strain in our animal facility exhibit a longer average healthy life span than rats of Dark Agouit (DA) strain. Since chronic activation of macrophages contributes to chronic low level inflammation common in older age, elucidation of the changes in middle-aged rats could be useful in prevention of unbalanced inflammatory response in advanced age. We have analysed the phenotype of unelicited and thioglycollate-elicited peritoneal macrophages from young and middle-aged DA and AO rats and tested functions of these cells following stimulation with lipopolysaccharide (LPS) in vitro. Unelicited cells from middle-aged DA rats produced higher amounts of proinflammatory mediators interleukin-6 (IL-6) and nitric oxide (NO), but have a diminished response to LPS stimulation then cells from young rats, in spite of increased frequency of TLR4- and CD14-expressing mature macrophages. Injection of thioglycollate robustly increased overall cytokine production in young rats' macrophages, while diminishing their response to LPS stimulation. In middle-aged DA rats injection of thioglycollate diminished IL-6 production, but increased it in response to LPS stimulation. Quite the contrary to DA rats, the macrophages from middle-aged AO rats have released diminished levels of TNF-alpha, and NO, whereas urea production was strongly increased, when compared to the macrophages from young rats. Although the thioglycollate injection has increased the proportion of CD86(+)MHCII(+) mature macrophages in young rats, and percentages of activated TLR4(+) macrophages in both age groups of AO rats, it has not affected the cytokine production in young rats' macrophages, and the TNF-alpha production in middle-aged rats' macrophages. Moreover, the injection of thioglycollate has robustly increased the production of urea in macrophages derived from both age groups of AO rats. Although middle-aged rats of both strains were healthy during experiment, differences between the inflam

Background: Aging influences immune response and susceptibility to EAE in a strain specific manner. The study was designed to examine influence of aging on EAE induction in Albino Oxford (AO) rats. Results: Differently from 3-month-old (young) rats, which were resistant to EAE induction, the majority of aged (24-26-month-old) rats developed mild chronic form of EAE. On 16th day post-immunization, when in aged rats the neurological deficit reached plateau, more mononuclear cells, including CD4+ T lymphocytes was retrieved from spinal cord of aged than young rats. The frequencies of IL-17+ and GM-CSF+ cells within spinal cord infiltrating CD4+ lymphocytes were greater in aged rats. To their increased frequency contributed the expansion of GM-CSF + IL-17 + IFN-gamma+ cells, which are highly pathogenic in mice. The expression of the cytokines (IL-1 beta and IL-23/p19) driving GM-CSF + IL-17 + IFN-gamma + cell differentiation in mice was also augmented in aged rat spinal cord mononuclear cells. Additionally, in aged rat spinal cord the expansion of GM-CSF + IL-17-IFN-gamma- CD4+ T lymphocytes was found. Consistently, the expression of mRNAs for IL-3, the cytokine exhibiting the same expression pattern as GM-CSF, and IL-7, the cytokine driving differentiation of GM-CSF + IL-17-IFN-gamma- CD4 + lymphocytes in mice, was upregulated in aged rat spinal cord mononuclear cells, and the tissue, respectively. This was in accordance with the enhanced generation of the brain antigen-specific GM-CSF+ CD4+ lymphocytes in aged rat draining lymph nodes, as suggested by (i) the higher frequency of GM-CSF+ cells (reflecting the expansion of IL-17-IFN-gamma- cells) within their CD4+ lymphocytes and (ii) the upregulated GM-CSF and IL-3 mRNA expression in fresh CD4+ lymphocytes and MBP-stimulated draining lymph node cells and IL-7 mRNA in lymph node tissue from aged rats. In agreement with the upregulated GM-CSF expression in aged rats, strikingly more CD11b + CD45(int) (activated microglia

The influence of aging on phagocytic, antigen presenting and secretory capacity of resident Albino Oxford rat peritoneal macrophages cultured for 24 hours in medium alone and in the presence of either LPS or IL-4 was examined. The frequencies of CD68+, CD169+ and CCR7+ cells were comparable among fresh peritoneal cells from young (3-months-old) and aged (i8-months-old) rats, whereas those of CD163+, MHCII+ and CD86+ cells were lower within the same cell population in aged relative to young rats. Congruent with the latter findings, aged rat macrophages cultured in medium alone exhibited impaired allostimulatory properties. Additionally, their zymosan phagocytizing ability was reduced. Differently from young rat macrophages, aged rat macrophages changed neither allostimulatory nor zymosan phagocytizing ability upon in vitro treatment with either LPS or IL-4. In the presence of LPS, NO production comparably increased in macrophages from young and aged rats. However, in the presence of either LPS or IL-4 urea production increased only in macrophages from aged rats. Differently from LPS, which increased the prototypic proinflamrnatory cytokine production in macrophages from rats of both ages, the diminishing effect of IL-4 on their production was evident only in macrophages from young rats. Collectively, our results suggest that aging, besides diminishing influence on macrophage allostimulatory and zymosan phagocytizing ability, may impair their responsiveness to IL-4 in vitro. Consequently, an altered efficacy of inflammatory/immune responses in aged rats may be expected.

In aquatic and surrounding terrestrial ecosystems, snakes of the genus Natrix are among the top predators, feeding predominantly on fishes and amphibians, but also on other reptiles and small mammals. In the diets of Natrix natrix and N. tessellata, preferred food items vary geographically and during ontogeny. To understand these variations, we collected data on their diet composition in several habitats (river, wetlands, and two types of lakes), some of which are under severe anthropogenic pressures. Both Natrix species were able to quickly adapt to changes in available prey, and to feed even on non-indigenous, invasive, and potentially hazardous fish. Disturbed ecosystems are particularly susceptible to invasions. Therefore, if alien fishes become dominant, they may threaten populations of native snakes. On the other hand, semi-aquatic snakes can contribute to natural regulation of alien fish species abundance. The preliminary results presented herein emphasize the urgent need for integrative studies of natricine snakes and their prey ecology under various and/or dynamic circumstances. Better understanding of the functioning of different aquatic ecosystems may enable proper conservation and restoration for these snake species and their habitats.