Effect Of Peritoneal Macrophages Research Articles

β-Sitosterol Alleviates Inflammatory Response via Inhibiting the Activation of ERK/p38 and NF-κB Pathways in LPS-Exposed BV2 Cells.

Neurodegenerative disease is a disease state in which neurons in the spinal cord and brain are lost. Studies show that sustained neuroinflammatory reactions release toxic factors, damage neurons, and lead to neurodegenerative diseases. Therefore, inhibiting neuroinflammation may be an effective measure to alleviate neurodegenerative diseases. Microglia is an important participant in the neuroinflammatory response. β-Sitosterol (BS) is widely found in various vegetable oils, nuts, and other plant seeds. Studies have found that BS has a wide range of anti-inflammatory effects in peritoneal macrophages and other peripheral tissues. However, no studies have reported the effect of BS that impacts microglia activity. Herein, we further study the effect of BS on impacts microglia activity. Firstly, BV2, a murine microglial cell, was treated with different concentrations of BS prior to stimulation of LPS, and then the inflammatory mediators and the expression of related signaling molecules were tested. The inflammatory response results illustrated that BS treatment can reduce the LPS-induced expression of inflammatory mediators (interleukin-6 (IL-6), inducible nitric oxide (iNOS), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2(COX-2)). The related signaling pathway analysis demonstrated that BS treatment can inhibit the LPS-induced activation of p38, ERK, and NF-κB pathways. To sum up, the results demonstrated that BS impacts microglia activity via repressing the activation of p38, ERK, and NF-κB pathways.

Abstract 1552: Resveratrol increases sensitivity of human peritoneal cancer cells to macrophage-mediated cytolysis

Abstract The peritoneal cavity contains numerous cells of the immune system capable of mediating antitumor effects. The persistence of cancer in this environment is thought to be due, in part, to the capacity of these cells to circumvent immunologic detection and destruction. Nevertheless, the presence of an immune system within the peritoneal cavity provides the opportunity to elicit tumor cytolysis by resident and/or circulating immune cells mobilized from the peripheral blood. One strategy that may be applicable in this setting is the introduction of compounds into the peritoneal cavity that enhance the sensitivity of malignant cells to activated immune cells. Ideally, these compounds would be tolerated by normal tissues while exerting clinical effects on tumor tissues. In the current investigation, we explored the capacity of the natural product, resveratrol, to modulate sensitivity of human peritoneal cancer cells to the lytic effects of activated human peripheral blood monocytes (PBM). PBM were primed with gamma interferon (IFN) followed by lipopolysaccharide (LPS) as a second signal. Target cells consisted of newly established cells lines from surgical specimens of patients with peritoneal carcinaomatosis (PC) or metastatic colorectal cancer (CRC). Cytolysis was determined following activation with a 24 hour 51Chromium release assay. Control activation of PBM with medium elicted 25 lytic units (LU) and < 5 LU against untreated CRC and PC cells respectively. These values were not changed significantly when resveratrol-pretreated tumor cells were used as targets. In contrast, PBM fully activated with IFN/LPS elicted 224 and 118 LU against untreated CRC and PC respectively and 316 and 199 LU against resveratrol-pretreated CRC and PC respectively. These results were investigated further to determine the effects of resveratrol pretreatment on expression of genes associated with immunologic sensitivity. A real time PCR assay indicated significantly increased expression of death receptors of the TNF superfamily as a consequence of resveratrol pretreatment. Subsequent studies demonstrated that recombinant TNF and TRAIL ligands could significantly inhibit proliferation of resveratrol-pretreated CRC and PC greater than media-pretreated cells. The results of this study demonstrate that human peritoneal cancer cells can be rendered significantly more sensitive to the cytolytic effects of activated human monocytes and macrophages when exposed to the natural product, resveratrol. Given the substantial quantity of macrophages in the peritoneal cavitry of humans, and the influence of malignant tissues on increasing these numbers further, modalities designed to exploit the tumor cytolytic effects of peritoneal macrophages for the treatment of human peritoneal cancers should be explored. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1552. doi:1538-7445.AM2012-1552

Endometrium from women with endometriosis shows increased proliferation activity

Examination of 631 infertile women, including 434 women with endometriosis and 197 without endometriosis, revealed an increasing incidence of endometrial polyps, especially in the test subjects with endometriosis, and advanced stages of endometriosis. Expression of Ki-67 and Bcl-2 proteins and MTT assay results were significantly higher in endometrium of patients with endometriosis than in patients without endometriosis. These showed increased proliferation activity and cell proliferation markers not only clinically but also pathologically.

Beryllium fluoride-induced cell proliferation: a process requiring P21ras-dependent activated signal transduction and NF-κB-dependent gene regulation

We studied the effect of beryllium fluoride on murine peritoneal macrophages and determined its effects on signal transduction and genetic regulation. At low concentration (1-5 nM), BeF(2) caused an approximate twofold increase in [(3)H]thymidine uptake and cell number, but above 5 nM, it showed cytotoxic effects. BeF(2) increased cellular inositol (1,4,5)trisphosphate (IP(3)) and [Ca(2)(+)](i) about twofold. The rise in [Ca(2)(+)](i) occurred consequent to release from IP(3)-sensitive Ca(2)(+) stores and from influx, mainly via L-type channels. A significant increase in the levels of MEK1, ERK1, p38 MAPK, and JNK phosphorylation was observed in BeF(2)-exposed macrophages. The levels of NF-kappaB and CREB transcription factors and the proto-oncogenes c-fos and c-myc were also elevated significantly. Intracellular Ca(2)(+) chelation blocked the effect of BeF(2). We conclude that BeF(2) at low concentration exerts its mitogenic effects in peritoneal macrophages by elevating [Ca(2)(+)](i), which triggers the activation of p21(ras)-dependent MAPK signaling cascades.

Preserved solid lipid nanoparticles (SLN) at low concentrations do cause neither direct nor indirect cytotoxic effects in peritoneal macrophages

In order to investigate the interaction of preserved solid lipid nanoparticles (SLN) with murine peritoneal macrophages (MØ), cytotoxicity and proinflammatory effects of two different solid lipid nanoparticles (SLN) preparations consisting of either compritol (CO) or cetyl palmitate (CP) preserved with thiomersal were analyzed. Concentration-dependent cytotoxic effects were observed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Secretion of interleukin-6 by MØ following incubation with CO and CP SLN did not differ from secretion by untreated cells; proinflammatory cytokines interleukin-12 and tumor-necrosis-factor-α as further indicators of immunomodulatory effects were not detectable. These findings paralleled our previous findings that unpreserved CO and CP SLN did not induce immunomodulatory effects but cytotoxicity at higher concentrations. There were no synergistic cytotoxic effects of preservative and SLN. Thus, preservation of SLN using thiomersal does not appear to cause increased cytotoxicity and immunomodulatory effects following incubation with MØ.

In-vitro enhancement of mouse embryonic development by co-culture with peritoneal macrophages.

The effects of peritoneal macrophages on mouse fertilization and embryonic development in vitro were examined by a co-culture method. In experiment 1, oocytes from F1 strain mice were inseminated and cultured with a monolayer of peritoneal macrophages to determine the effects of the macrophages on fertilization. In experiment 2, 1-cell embryos, fertilized in vivo from either a non-blocking or a blocking strain, were also incubated with peritoneal macrophages to determine whether these cells overcame the developmental arrest. Although the peritoneal macrophages had an adverse effect on fertilization in the F1 strain, embryonic development was significantly improved by the co-culture. This beneficial effect on embryonic development was also observed in the embryos fertilized in vivo from the strain that exhibited a 2-cell block. These results suggest that peritoneal macrophages provide an effective co-culture system for the in-vitro development of mouse embryos.

Effects of peritoneal macrophages from patients with endometriosis on the proliferation of endometrial carcinoma cell line ECC-1

Endometriosis has been shown to be associated with increased number and activity of peritoneal macrophages. The peritoneal macrophage-conditioned media from 33 women with or without endometriosis were studied for their effects on an endometrial carcinoma cell line, ECC-1. The media from six of six stage III/IV cases demonstrated a mitogenic effect, which was blocked by an antibody to epidermal growth factor receptor. However, the conditioned media from seven of nine stage I/II cases and 14 of 18 normal women did not show a mitogenic effect. The difference between stage III/IV and the other two groups was significant (p less than 0.01). The incorporation of tritium-thymidine was three times higher with the media from stage III/IV cases, as compared with that of controls. When purified cytokines were tested in the tritium-thymidine uptake assay, only epidermal growth factor-transforming growth factor-alpha was mitogenic on ECC-1, whereas tumor necrosis factor, interleukin-1, and platelet-derived growth factor had no effect. Thus peritoneal macrophages in patients with endometriosis may play an important role in the progression of endometriosis, and the noted effects could be mediated by epidermal growth factor or a related growth factor.

Effect of Peritoneal Macrophages from Intermittent Peritoneal Dialysis Patients on Lymphocytes in Culture

To investigate the biological activity of peritoneal macrophages, cells isolated from dialysate of 30 patients with end-stage kidney disease treated by intermittent peritoneal dialysis and from ascites of 6 patients with cardiac insufficiency (relative control group) were added to autologous, phytohemagglutinin (PHA)-stimulated lymphocyte cultures. Macrophages of dialyzed patients induced a dose-dependent increase in autologous lymphocyte proliferation, whereas macrophages obtained from control subjects exerted a suppressive effect on those cultures. The enhanced lymphocyte proliferation by macrophages from dialyzed patients was corroborated by the increased metabolic activity of macrophages as evaluated by the increased nitro blue tetrazolium (NBT) reduction test and increased functional expression of Fc receptors (FcR). The subpopulation of macrophages from patients with HLA-DR antigens as determined by HB55 monoclonal antibody, inhibited lymphoproliferation in vitro. We conclude that peritoneal macrophages from dialyzed patients represent a heterogenous population of cells with different phenotypic and functional characteristics.

Effects of peritoneal macrophages from patients with endometriosis on the proliferation of endometrial carcinoma cell line ECC-1

Endometriosis has been shown to be associated with increased number and activity of peritoneal macrophages. The peritoneal macrophage-conditioned media from 33 women with or without endometriosis were studied for their effects on an endometrial carcinoma cell line, ECC-1. The media from six of six stage III/IV cases demonstrated a mitogenic effect, which was blocked by an antibody to epidermal growth factor receptor. However, the conditioned media from seven of nine stage 1/11 cases and 14 of 18 normal women did not show a mitogenic effect. The difference between stage III/IV and the other two groups was significant (p < 0.01 ). The incorporation of tritium-thymidine was three times higher with the media from stage III/IV cases, as compared with that of controls. When purified cytokines were tested in the tritium-thymidine uptake assay, only epidermal growth factor-transforming growth factor-α was mitogenic on ECC-1, whereas tumor necrosis factor, interleukin-1, and platelet-derived growth factor had no effect. Thus peritoneal macrophages in patients with endometriosis may play an important role in the progression of endometriosis, and the noted effects could be mediated by epidermal growth factor or a related growth factor. (AM J OBSTET GYNECOL 1991;165:1842-6.)

Effects on in Vitro Growth of Babesia Microti by Cells and Serum from B. Microti and Schistosoma Mansoni Infected Mice

The effect of peritoneal macrophages and serum from mice infected with Babesia microti, Schistosoma mansoni and B. microti plus S. mansoni on the growth of B. microti was assessed in short term in vitro cultures using the criterium of rate of incorporation of (3H)Hypoxan-thine. In the absence of serum, macrophages and supernatants from macrophage cultures failed to affect the in vitro growth of B. microti. In contrast, in the absen-de of macrophages, serum from mice infected with B. microti and with B. microti plus S. mansoni induced a marked inhibition of the in vitro growth of B. Microti. The level of inhibition induced by serum from mice infected with both S. mansoni and B. microti exceeded consistently that induced by serum from mice infected with B. microti only. Serum from mice only infected with S. mansoni induced a marked increase in the in vitro growth of B. microti. These findings suggest a suppression of B. microti in concurrently S. mansoni-infected mice induced by an immunological specific anti-2?. microti factor potentiated by the concurrent S. mansoni infection. The results do not indicate that activation of the mononuclear phagocytic system is of primary importance in suppression of B. microti in-concurrently S. mansoni infected mice.

The effects of peritoneal macrophages on monolayered luteal cell progestin secretion in the rat.

Functionally active or regressing luteal cells were obtained from pseudo-pregnant (psp) rats between days 5-8 of psp or on day 15 of psp, respectively. They were monolayer-cultured (10(6)/dish) in the presence of 0.2 micrograms/ml LH 2.0 micrograms/ml PRL and 10 micrograms/ml pregnenolone for 4 days with or without macrophages, although functionally active luteal cells secreted progesterone dominantly during day 1 of culture (Day 1), the amounts of progesterone and 20 alpha-OH-P secreted were inverted on Day 2, and the dominance of 20 alpha-OH-P continued from Day 2 to Day 4. In the functionally regressing luteal cell culture, more 20 alpha-OH-P than progesterone was secreted throughout the culture period. The addition of peritoneal macrophages (2.5 X 10(6] to the active luteal cell monolayer lengthened the dominance of progesterone secretion for an additional day and the inversion occurred on Day 3. The progestin ratio (progesterone/20 alpha-OH-P) on Day 2 was maintained significantly higher. The daily addition of macrophages maintained the progesterone dominance throughout the culture period. On the other hand, macrophages had no effect on luteal cells already functionally regressing. These results indicate that macrophages are effective in maintaining the progesterone secreting activity of luteal cells in vitro.

The effect of peritoneal macrophages from mice injected with Leishmania braziliensis on the in vitro growth of tumor cells.

Leishmania braziliensis reportedly is capable of producing a reduction in the growth of solid and ascites murine leukemia and lymphomas. The possibility that the inhibitory effect on the ascites tumor was produced by the activation of the macrophage peritoneal cell population was explored. It was observed that adherent cells from the peritoneal cavity of L. braziliensis injected mice caused a marked inhibitory effect on the in vitro growth of the 6C3HED lymphoma and EL-4 leukemia cells. This effect was dependent on the degree of the macrophage activation, was not produced by supernatants from cultures of activated macrophages, and it seems that contact cell between target and effector cells is necessary. In addition to being cytostatic, this effect was also cytotoxic. The L. braziliensis activated macrophages were also capable of suppressing the multiplication of normal cells induced by mitogen, but this was not observed if the cells were already undergoing multiplication. A similar cytostatic effect on the tumor cells was observed to be produced by the peritoneal non-adherent cell population of the L. braziliensis injected mice.