Macrophage Chemotactic Factor Research Articles

Salivary macrophage chemokines as potential biomarkers of gingivitis

ObjectiveThe present study aimed to analyze the salivary levels of macrophage-activating factor (MAF), macrophage-chemotactic factor (MCF), and macrophage migration inhibitory factor (MIF) in healthy and gingivitis patients, and to correlate between the concentrations of these chemo attractants with the intensity of gingival inflammation clinically.MethodsSixty saliva specimens were collected from periodontally healthy (n = 30), and gingivitis patients (n = 30). Bleeding on probing (BOP), Visible Plaque Index (VPI), and Simplified Modified Gingival Index (SMGI) were recorded through clinical examination. Salivary MAF, MCF, and MIF concentrations were assayed using enzyme-linked immunosorbent assays (ELISA). Statistical analysis was performed using SPSS (version 28). Total mean score for each biomarker was determined, and descriptive bivariate statistics were conducted to characterize the levels of biomarkers among the study groups. The difference in the biomarker levels among the study groups were analyzed by independent sample t test and one-way ANOVA. The diagnostic ability of the biomarkers was further tested by ROC curve analysis.ResultsSalivary levels of MAF was not significantly different between periodontally healthy individuals and gingivitis patients. The difference in MCF and MIF levels between patients with gingivitis and those with healthy periodontium was statistically significant (p 0.05 and p 0.001, respectively). When examined across the various stages of disease progression, MIF showed statistically significant difference among the three biomarkers (p 0.05). ROC curve analysis further revealed that area under the curve (AUC) for MIF has a better diagnostic capacity than MCF (AUC 0.981 vs. 0.673).ConclusionsOur results suggest that MIF could be considered as a potential salivary biomarker for gingivitis.

Repurposing bortezomib for choroidal neovascularization treatment via antagonizing VEGF-A and PDGF-D mediated signaling

Neovascular age-related macular degeneration (neoAMD) is the leading cause of blindness in AMD and manifests as choroidal neovascularization (CNV). Anti-vascular endothelial growth factor (VEGF) therapies are the mainstay treatments but with limited efficacy and cause detrimental effects on the retina after long-term application. These disadvantages warrant alternative strategy. Herein, we examined the effect on CNV by intravitreal injection of bortezomib, a reversible proteasome inhibitor, and further dissected the mechanism. Krypton red Laser was used to create CNV model in mice. The angiogenesis volume was assessed in choroidal flat-mount with isolectin GS-IB4 labeling and the leakage was examined with fluorescein fundus angiography. Injection of Borsub inhibited angiogenesis in the CNV model which was dose-dependent; the injection significantly inhibited leakage as well. Furthermore, Borsub injection reduced the contents of VEGF-A, macrophage chemotactic factor 1 (MCP-1), and platelet-derived growth factor (PDGF)-D but not PDGF-B, examined by enzyme-linked immunosorbent assay, in choroid/retinal pigment epithelium (RPE) tissue. These injections also reduced phospho-VEGFR-2 and phospho-PDGFRβ in choroid/RPE tissue examined by immunoblotting. Moreover, Borsub inhibited the recruitment of mural cells or macrophages to laser-injured spots. Injection of Borsub indicated negative effect on scotopic and photopic responses recorded by electroretinogram. Altogether, intravitreal injection of Borsub significantly reduced CNV by antagonizing VEGF-A/Flk-1 and PDGF-D/PDGFRβ pathways without impacting electroretinography parameters. Thus, Borsub may offer an invaluable therapy for the prevention and treatment of neoAMD.

Abstract P2-02-08: Slit2 induced anti-tumor activity may be mediated through metabolism driven immunomodulation

Abstract Metabolism of immune cells plays an important role in regulating tumor growth by modulating the anti-tumor M1 phenotype or pro-tumor M2 phenotype in macrophages. However, the role of bone marrow derived macrophages (BMDM) and their metabolic profile in promoting tumor growth is unknown. Slit2 is an anti-tumor molecule that is suppressed in breast cancer; however, the mechanism by which Slit2 mediates its function is not fully elucidated. We hypothesize that Slit2 mediated metabolic reprogramming of BMDMs favors anti-tumor M1 phenotype in these macrophages, which in turn reduces tumor growth. Here we assessed cellular metabolism in BMDMs from the MMTV-PyMT mouse, a model showing spontaneous tumor development. Shortly, age matched female mice with palpable tumors and control mice without tumors were treated with recombinant Slit2 (Slit2) or PBS intraperitoneally every third for 2 weeks (n=4 mice per group). Tumor volume was measured in each mouse before and at the end of treatment. Next, mice were euthanized and bone marrow was flushed from both the tibia and femor for culturing in vitro in the presence of macrophage chemotactic factor rich conditioned media. Rate of glycolysis was described based on extracellular acidification rate (ECAR) as measured by the Seahorse Bioanalyzer® under glycostress conditions. Lactate dehydrogenase (LDH) activity, which is linked with breast cancer progression and pro-tumor macrophage phenotype in experimental models, was also assayed using a commercially available kit. Finally, to elucidate potential pathways involved in Slit2 induced metabolic change, we assessed the expression of several proteins and factors involved in cellular metabolism. Firstly, we observed that PyMT mice treated with Slit2 showed lower tumor volume compared to mice treated with PBS confirming Slit2 anti-tumor activity. Hematoxylin & Eosin staining of tumor sections from these mice also showed better tissue structure, with a higher cytoplasm to nuclear ratio in Slit2 treated PyMT mice compared to PBS treated mice. Furthermore, BMDMs from PyMT mice show lower aerobic glycolysis with higher lactate dehydrogenase activity (LDH) compared to control mice. Moreover, treatment with Slit2 appeared to lower LDH activity and trended to increase glycolysis in the BMDMs isolated from Slit2 treated PyMT compared to PBS treated PyMT. Expression analyses using quantitative PCR showed a 2-4 fold decrease in PGC-1α and CPT-2 in Slit2 treated BMDMs, indicating a reduction in fatty acid oxidation in these cells. This coupled with a 3 fold increase in IL-6 expression, and 2-3 fold decrease in arginase and IL-10 expression in tumor tissue suggest a potential shift from pro-tumor M2 to anti-tumor M1 phenotype. In spite of these preliminary trends, changes in metabolism and associated signals may be clearer in isolated, enriched populations of macrophages alone. Nevertheless, our findings suggest that Slit2 reduces tumor growth by affecting immune cell metabolism. Furthermore, these studies provide novel evidence of the potential immunomodulatory effects of Slit2 on macrophages. This may lead to development of Slit2 as a novel non-invasive therapeutic strategy against highly aggressive and metastatic cancers associated with high mortality and low quality of life. Citation Format: Kaul K, Ahirwar DK, Benej M, Denko N, Ganju R. Slit2 induced anti-tumor activity may be mediated through metabolism driven immunomodulation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-08.

Metastasis Suppressors Regulate the Tumor Microenvironment by Blocking Recruitment of Prometastatic Tumor-Associated Macrophages.

Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. TNBC is characterized by reduced expression of metastasis suppressors such as Raf kinase inhibitory protein (RKIP), which inhibits tumor invasiveness. Mechanisms by which metastasis suppressors alter tumor cells are well characterized; however, their ability to regulate the tumor microenvironment and the importance of such regulation to metastasis suppression are incompletely understood. Here, we use species-specific RNA sequencing to show that RKIP expression in tumors markedly reduces the number and metastatic potential of infiltrating tumor-associated macrophages (TAM). TAMs isolated from nonmetastatic RKIP(+) tumors, relative to metastatic RKIP(-) tumors, exhibit a reduced ability to drive tumor cell invasion and decreased secretion of prometastatic factors, including PRGN, and shed TNFR2. RKIP regulates TAM recruitment by blocking HMGA2, resulting in reduced expression of numerous macrophage chemotactic factors, including CCL5. CCL5 overexpression in RKIP(+) tumors restores recruitment of prometastatic TAMs and intravasation, whereas treatment with the CCL5 receptor antagonist Maraviroc reduces TAM infiltration. These results highlight the importance of RKIP as a regulator of TAM recruitment through chemokines such as CCL5. The clinical significance of these interactions is underscored by our demonstration that a signature comprised of RKIP signaling and prometastatic TAM factors strikingly separates TNBC patients based on survival outcome. Collectively, our findings identify TAMs as a previously unsuspected mechanism by which the metastasis-suppressor RKIP regulates tumor invasiveness, and further suggest that TNBC patients with decreased RKIP activity and increased TAM infiltration may respond to macrophage-based therapeutics.

Depletion of tumor-associated macrophages slows the growth of chemically induced mouse lung adenocarcinomas.

Chronic inflammation is a risk factor for lung cancer, and low-dose aspirin intake reduces lung cancer risk. However, the roles that specific inflammatory cells and their products play in lung carcinogenesis have yet to be fully elucidated. In mice, alveolar macrophage numbers increase as lung tumors progress, and pulmonary macrophage programing changes within 2 weeks of carcinogen exposure. To examine how macrophages specifically affect lung tumor progression, they were depleted in mice bearing urethane-induced lung tumors using clodronate-encapsulated liposomes. Alveolar macrophage populations decreased to ≤50% of control levels after 4–6 weeks of liposomal clodronate treatment. Tumor burden decreased by 50% compared to vehicle treated mice, and tumor cell proliferation, as measured by Ki67 staining, was also attenuated. Pulmonary fluid levels of insulin-like growth factor-I, CXCL1, IL-6, and CCL2 diminished with clodronate liposome treatment. Tumor-associated macrophages expressed markers of both M1 and M2 programing in vehicle and clodronate liposome-treated mice. Mice lacking CCR2 (the receptor for macrophage chemotactic factor CCL2) had comparable numbers of alveolar macrophages and showed no difference in tumor growth rates when compared to similarly treated wild-type mice suggesting that while CCL2 may recruit macrophages to lung tumor microenvironments, redundant pathways can compensate when CCL2/CCR2 signaling is inactivated. Depletion of pulmonary macrophages rather than inhibition of their recruitment may be an advantageous strategy for attenuating lung cancer progression.

Two faces of Schwann cell dedifferentiation in peripheral neurodegenerative diseases: pro-demyelinating and axon-preservative functions.

In vertebrates, Schwann cells are glial cells that form a myelin sheath, which produces the saltatory conduction of neural impulses in the peripheral nervous system (Sherman and Brophy, 2005). In the case of abnormal myelin sheath generation due to genetic mutations or myelin sheath destruction by acquired nerve damage induced by inflammation or drugs, problems arise in the peripheral nervous system, leading to muscle atrophy or sensory disorders (Sherman and Brophy, 2005; Jessen and Mirsky, 2008). During the embryonic period, the neural crest cells migrate along with growing peripheral axons. A Schwann cell precursor that has finished migrating and has attached to a growing nerve may wrap around a few or as many as dozens of axons, but ultimately only target a single axon that requires a myelin sheath in response to a certain stimulus (Sherman and Brophy, 2005; Jessen and Mirsky, 2008). In the period of Schwann cell generation, the cell is called Schwann cell progenitor or immature Schwann cell. Subsequently, the Schwann cell begins the process of myelin-related gene expression and wraps the axon with the elongated Schwann cell membrane, which continues throughout the postnatal period to complete the myelin sheath formation (Sherman and Brophy, 2005; Jessen and Mirsky, 2008). The mature myelin sheath will last a lifetime, except when damage, such as nerve injury, occurs. Acute and chronic demyelinating peripheral neuropathies are primary diseases that cause myelin destruction in adults (Jessen and Mirsky, 2008). When a peripheral nerve is physically severed, distal axons are completely degenerated, and the Schwann cells wrapped around the axons directly participate in the degeneration of the myelin sheath, which leads to demyelination (Jessen and Mirsky, 2008). Afterwards, macrophages that migrate from the blood assist in completely removing the degenerated axon and the myelin sheath (Martini et al., 2008). Meanwhile, in inflammatory demyelinating diseases, acute or chronic form of demyelination may occur regardless of axonal damage, and it is considered that demyelination occurs due to local inflammation caused by autoimmune mechanisms, which may attack components of the myelin sheath or junctional regions (Pollard and Armati, 2011).

CXCL17 is a novel macrophage recruitment factor (P6215)

Abstract Chemokines chemotactic molecules that regulate the development of immune responses, There are 48 members of this human gene superfamily and for most we have a good understanding of their biology. Some, however, remain poorly characterized including CXCL17 which was the last ligand of this superfamily to be described. Recently, we reported that CXCL17 is an important mucosal chemokine that exhibits antimicrobial activity and is elevated in the bronchoalveolar lavage fluid (BALf) of patients with idiopathic pulmonary fibrosis. We have now explored the chemotactic properties of CXCL17. In vitro, CXCL17 induces chemotactic responses in monocytic cell lines and in macrophages. We also analyzed CXCL17 effects in vivo and observed that it recruits F4/80+ macrophages to the peritoneal cavity. We have obtained a Cxcl17 (-/-) mouse and observed that it exhibits decreased numbers of macrophages is several mucosal tissues when compared to wild type mice. We conclude that CXCL17 is an important macrophage chemotactic factor. In addition, this information indicates that CXCL17 is likely involved in macrophage recruitment both under homeostatic conditions and also during inflammatory responses. Importantly, CXCL17 is likely to participate in human disease as we have already observed high levels of this chemokine in IPF. Taken together, our data strongly suggests that CXCL17 may be involved in human inflammatory diseases that affect the mucosa.

Cavin1; a regulator of lung function and macrophage phenotype.

Caveolae are cell membrane invaginations that are highly abundant in adipose tissue, endothelial cells and the lung. The formation of caveolae is dependent on the expression of various structural proteins that serve as scaffolding for these membrane invaginations. Cavin1 is a newly identified structural protein whose deficiency in mice leads to loss of caveolae formation and to development of a lipodystrophic phenotype. In this study, we sought to investigate the functional role of Cavin1 in the lung. Cavin1 deficient mice possessed dramatically altered distal lung morphology and exhibited significant physiological alterations, notably, increased lung elastance. The changes in distal lung architecture were associated with hypercellularity and the accumulation of lung macrophages. The increases in lung macrophages occurred without changes to circulating numbers of mononuclear cells and without evidence for increased proliferation. However, the increases in lung macrophages were associated with higher levels of macrophage chemotactic factors CXCL2 and CCL2 in BAL fluid from Cavin1−/− mice suggesting a possible mechanism by which these cells accumulate. In addition, lung macrophages from Cavin1−/− mice were larger and displayed measurable differences in gene expression when compared to macrophages from wild-type mice. Interestingly, macrophages were also increased in adipose tissue but not in liver, kidney or skeletal muscle from Cavin1−/− mice, and similar tissue specificity for macrophage accumulation was observed in lungs and adipose tissue from Caveolin1−/− mice. In conclusion, this study demonstrates an important role for Cavin1 in lung homeostasis and suggests that caveolae structural proteins are necessary for regulating macrophage number and phenotype in the lung.

Both Tissue-Derived and Bone Marrow-Derived Host IL-17 Producing Cells Are Required for Preventing Acute Graft-Versus-Host Disease

Abstract 2970Th17 is a newly identified T cell lineage, which secretes the proinflammatory cytokine IL-17. Th17 have been shown to play a crucial role in some immune-mediated diseases. We have reported that host-derived IL-17 has a protective effect against acute graft-versus-host disease (GVHD). In contrast, donor-derived IL-17 exacerbates chronic GVHD in rodent models. Briefly, in acute GVHD model, lethally irradiated IL-17 knockout (KO) recipient mice receiving allogeneic BM with low dose splenocytes developed more severe acute gut GVHD compared to wild type (WT) host mice and finally half of them died (p<0.05). To demonstrate the mechanisms of protective role of host derived IL-17 against acute GVHD in further detail, first we determined in vivo gut epithelial permeability by using FITC-dextran. No significant difference was observed between WT mice and IL-17KO mice, even in GVHD induced mice. Next, to exclude the possibility that alloreactivity of host IL-17KO derived mature dendritic cells (DCs) could be much more than that of WT DCs, mixed leukocyte reaction (MLR) was performed using stimulators from WT or IL-17KO mature DCs and responders from WT allogeneic splenocytes. There was no significant difference between WT mature DCs and IL-17KO mature DCs in thymidine uptake and percentage of responder cells producing IFN-γ or TNF-α. However, when DCs were cultured from BM cells with GM-CSF, co-stimulatory molecules such as CD80 and CD86 were expressed much stronger and from earlier time point on IL-17KO DCs compared with WT DCs. This suggested that DCs from IL-17KO tend to be activated much easier, resulting in much severe GVHD. In addition, when recombinant IL-17 was added into MLR mixture (Stimulator: Balb/c IL-17KO mature DCs, Responder: B6 IL-17KO splenocytes), proliferation was significantly decreased, demonstrating that IL-17 has inhibitory effect on alloreaciton. Next, much higher number of infiltrated monocyte/macrophage cluster was observed in spleen and gut in IL-17KO host mice. Residual host-typed peritoneal macrophages in IL-17KO host mice were highly activated with the expression of TNF-α, while activation of donor-typed macrophages was much less with the production of anti-inflammatory cytokine IL-10. Activated monocytes/macrophages in IL-17KO recipients might migrate into inflamed tissue much easier, partially because lack of IL-17 dose not block some macrophage chemotactic factors such as IP-10, RANTES. Finally to explore which host IL-17 producing cells are necessary for protection from acute GVHD, that is, BM-derived IL-17 producing cells or tissue derived IL-17 producing cells such as Paneth cells in the gut, [IL-17KO→WT], [WT→IL-17KO], [WT→WT], and [IL-17KO→IL-17KO] chimeric mice (Balb/c background) were created by reconstituting lethally irradiated WT or IL-17 KO Balb/c (H-2d) with BM cells from WT or IL-17 KO Balb/c mice. Four months later, chimeras were re-irradiated with 8Gy TBI and injected with WT C57BL/6(H-2b) BM plus low dose splenocytes to induce acute GVHD. Although [WT→WT] chimeric recipients were all alive, all [IL-17KO→IL-17KO] chimeric mice died of severe GVHD. In both [WT→IL-17KO] and [IL-17KO→WT] chimeras, half of them died with less GVHD compared to [IL-17KO→IL-17KO] recipients as shown below. This result indicated that as well as tissue derived IL-17, host BM derived IL-17 is necessary for protection from acute GVHD. In conclusion, host-derived IL-17 has a protective effect against acute GVHD due to in part by regulating APCs (monocytes/macrophages/DCs) activation and migration into GVHD target tissues. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Extracellular Matrix from Porcine Small Intestinal Submucosa (SIS) as Immune Adjuvants

Porcine small intestinal submucosa (SIS) of Cook Biotech is licensed and widely used for tissue remodeling in humans. SIS was shown to be highly effective as an adjuvant in model studies with prostate and ovarian cancer vaccines. However, SIS adjuvanticity relative to alum, another important human-licensed adjuvant, has not yet been delineated in terms of activation of innate immunity via inflammasomes and boosting of antibody responses to soluble proteins and hapten-protein conjugates. We used ovalbumin, and a hapten-protein conjugate, phthalate-keyhole limpet hemocyanin. The evaluation of SIS was conducted in BALB/c and C57BL/6 mice using both intraperitoneal and subcutaneous routes. Inflammatory responses were studied by microarray profiling of chemokines and cytokines and by qPCR of inflammasomes-related genes. Results showed that SIS affected cytokine and chemokines microenvironments such as up-regulation of IL-4 and CD30-ligand and activation of chemotactic factors LIX and KC (neutrophil chemotactic factors), MCP-1 (monocytes chemotactic factors), MIP 1-α (macrophage chemotactic factor) and lymphotactin, as well as, growth factors like M-CSF. SIS also promoted gene expression of Nod-like receptors (NLR) and associated downstream effectors. However, in contrast to alum, SIS had no effects on pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) or NLRP3, but it appeared to promote both Th1 and Th2 responses under different conditions. Lastly, it was as effective as alum in engendering a lasting and specific antibody response, primarily of IgG1 type.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Extracellular matrix from porcine small intestinal submucosa as immune adjuvants (52.21)

Abstract Porcine small intestinal submucosa (SIS) of Cook Biotech is widely used in tissue remodeling. It also proved safe and effective in enhancing efficacy of a prostate cancer vaccine. In this study, we compared SIS-adjuvanticity with alum’s in mobilizing innate immunity via inflammasomes, and in boosting antibody response to soluble proteins, ovalbumin, and a hapten-protein conjugate, phthalate-KLH. This evaluation carried out in BALB/c, C57Bl/6 and lupus-prone NZB/WF1 mice was done by both Intraperitoneal and subcutaneous routes of immunization. Methods involved determination of antibody titer, isotyping, microarray profiling of cytokines and chemokines and qPCR of inflammasomes-related genes. Results clearly highlighted the difference between SIS and alum. SIS provoked neither pro-inflammatory cytokines (IL-6, IL-1β, and TNFα) nor NLRP3 inflammasomes as alum did, but it did up-regulate IL4 and CD30-ligand. SIS also activated chemotactic factors LIX and KC (neutrophil chemotactic factors), MCP 1 (monocyte chemotactic factors), MCSF and MIP 1-α (macrophage chemotactic factor) and Lympotactin, albeit a little less than Alum. SIS, however, was as effective as alum in engendering lasting and specific antibody responses, primarily of IgG1 type, but proved inconsequential in induction of anti-DNA response or renal pathology. In conclusion, although both alum and SIS induced Th2 type immune response, SIS was much less inflammatory than alum.

Glutathione peroxidase-1 protects against cigarette smoke-induced lung inflammation in mice

Reactive oxygen species (ROS) produced from cigarette smoke cause oxidative lung damage including protein denaturation, lipid peroxidation, and DNA damage. Glutathione peroxidase-1 (gpx-1) is a detoxifying enzyme that may protect lungs from such damage. The aim of this study was to determine whether gpx-1 protects the lung against oxidative stress-induced lung inflammation in vivo. Male wild-type (WT) or gpx-1(-/-) mice were exposed to cigarette smoke generated from nine cigarettes per day for 4 days to induce oxidative stress and lung inflammation. The effect of the gpx mimetic ebselen on cigarette smoke-induced lung inflammation was evaluated when given prophylactically and therapeutically, i.e., during established inflammation. Mice were killed, and the lungs were lavaged with PBS and then harvested for genomic and proteomic analysis. Gpx-1(-/-) mice exposed to cigarette smoke had enhanced BALF neutrophils, macrophages, proteolytic burden, whole lung IL-17A, and MIP1alpha mRNA compared with WT mice. The gpx mimetic ebselen (10 and 100 microM) inhibited cigarette smoke extract-induced oxidation of MH-S cells in vitro and inhibited cigarette smoke-induced increases in BALF macrophages, neutrophils, proteolytic burden, and macrophage and neutrophil chemotactic factor gene expression when administered prophylactically. In addition, ebselen inhibited established BALF inflammation when administered therapeutically. These data show that gpx-1 protects against cigarette smoke-induced lung inflammation, and agents that mimic the actions of gpx-1 may have therapeutic utility in inflammatory lung diseases where cigarette smoke plays a role.

Delayed accumulation of activated macrophages and inhibition of remyelination after spinal cord injury in an adult rodent model

Inhibition of remyelination is part of the complex problem of persistent dysfunction after spinal cord injury (SCI), and residual myelin debris may be a factor that inhibits remyelination. Phagocytosis by microglial cells and by macrophages that migrate from blood vessels plays a major role in the clearance of myelin debris. The object of this study was to investigate the mechanisms underlying the failure of significant remyelination after SCI. The authors investigated macrophage recruitment and related factors in rats by comparing a contusion model (representing contusive SCI with residual myelin debris and failure of remyelination) with a model consisting of chemical demyelination by lysophosphatidylcholine (representing multiple sclerosis with early clearance of myelin debris and remyelination). The origin of infiltrating macrophages was investigated using mice transplanted with bone marrow cells from green fluorescent protein-transfected mice. The changes in levels of residual myelin debris and the infiltration of activated macrophages in demyelinated lesions were investigated by immunostaining at 2, 4, and 7 days postinjury. To investigate various factors that might be involved, the authors also investigated gene expression of macrophage chemotactic factors and adhesion factors. Activated macrophages coexpressing green fluorescent protein constituted the major cell population in the lesions, indicating that the macrophages in both models were mainly derived from the bone marrow, and that very few were derived from the intrinsic microglia. Immunostaining showed that in the contusion model, myelin debris persisted for a long period, and the infiltration of macrophages was significantly delayed. Among the chemotactic factors, the levels of monocyte chemoattractant protein-1 and granulocyte-macrophage colony-stimulating factor were lower in the contusion model at 2 and 4 days postinjury. The results suggest that the delayed infiltration of activated macrophages is related to persistence of myelin debris after contusive SCI, resulting in the inhibition of remyelination.

Acute but not chronic macrophage recruitment in filarial infections in mice is dependent on C‐C chemokine ligand 2

Macrophages play an important role in the formation of granulomas and the clearance of Brugia pahangi infections in mice. However, the factors responsible for the recruitment of these cells to the site of infection are not known. In this study we examined the role of the C-C chemokine ligand 2 (CCL2; also known as macrophage chemotactic factor - MCP1) in macrophage recruitment in intraperitoneal infections with B. pahangi. We observed that CCL2 was expressed by peritoneal exudate cells and was present in the sera of wild-type mice. Serum levels of CCL2 peaked twice during the immune response, once during the early, acute phase and again during the late, chronic phase. To further elucidate the role of this chemokine in the anti-filarial immune response, we compared CCL2 deficient (CCL2(-/-)) mice to wild-type mice. We observed that macrophage recruitment was impaired only during the acute phase in the former. While macrophage recruitment was unaffected during the chronic phase, increased accumulation of B and T lymphocytes was seen in these mice. We further report that larval clearance and the in vitro adhesion of PECs to larvae were unimpaired in these mice.

MCP-1 deficiency causes altered inflammation with impaired skeletal muscle regeneration

We examined the role of MCP-1, a potent chemotactic and activating factor for macrophages, in perfusion, inflammation, and skeletal muscle regeneration post-ischemic injury. MCP-1-/- or C57Bl/6J control mice [wild-type (WT)] underwent femoral artery excision (FAE). Muscles were collected for histology, assessment of tissue chemokines, and activity measurements of lactate dehydrogenase (LDH) and myeloperoxidase. In MCP-1-/- mice, restoration of perfusion was delayed, and LDH and fiber size, indicators of muscle regeneration, were decreased. Altered inflammation was observed with increased neutrophil accumulation in MCP-1-/- versus WT mice at Days 1 and 3 (P< or =0.003), whereas fewer macrophages were present in MCP-1-/- mice at Day 3. As necrotic tissue was removed in WT mice, macrophages decreased (Day 7). In contrast, macrophage accumulation in MCP-1-/- was increased in association with residual necrotic tissue and impaired muscle regeneration. Consistent with altered inflammation, neutrophil chemotactic factors (keratinocyte-derived chemokine and macrophage inflammatory protein-2) were increased at Day 1 post-FAE. The macrophage chemotactic factor MCP-5 was increased significantly in WT mice at Day 3 compared with MCP-1-/- mice. However, at post-FAE Day 7, MCP-5 was significantly elevated in MCP-1-/- mice versus WT mice. Addition of exogenous MCP-1 did not induce proliferation in murine myoblasts (C2C12 cells) in vitro. MCP-1 is essential for reperfusion and the successful completion of normal skeletal muscle regeneration after ischemic tissue injury. Impaired muscle regeneration in MCP-1-/- mice suggests an important role for macrophages and MCP-1 in tissue reparative processes.

Metabolic Response to Stress in the Neonate Who Has Surgery

After completing this article, readers should be able to: 1. Describe the basic metabolic pathways involved in neonatal nutrition. 2. Describe the effect of stress on nutrition and metabolism in the neonate undergoing surgery. 3. Describe the differences in the metabolic response to stress between an adult and a neonate. Over the past 4 decades, there have been remarkable improvements in our ability to care for critically ill infants. Progress in surgical and critical care of neonates has led to improved survival rates. Our understanding of the nutritional requirements of infants continues to advance. In contrast to years past, practitioners caring for critically ill infants undergoing surgery today have various nutritional options, including specialized parenteral and enteral formulations. Although our understanding of host defense and nutritional support continues to evolve, the interplay between the immune system and metabolism is being investigated. Hence, we are improving the match between the infant’s energy expenditure and nutritional requirements. Critical to further progress is additional understanding of the metabolic response of a neonate to surgical stress. All living organisms require energy to survive. Fuel sources enter into complex metabolic cascades to form the ultimate energy substrate, adenosine triphosphate (ATP), a fuel needed to drive and maintain all physiologic systems. Under stressful conditions, intrinsic substrate mobilizes to synthesize additional energy substrate. In essence, host substrate is mobilized for the promotion of healing after injury. Cytokines, released in response to injury, drive the catabolic response to stress, but in abundance, as with the systemic inflammatory response syndrome (SIRS), cytokines are detrimental to the organism. The nutritional requirements of a neonate are significantly greater than those of an adult because not only are there requirements for substrate intake to fulfill basic metabolic needs, but there are metabolic needs to maintain rapid and continued growth and development. Furthermore, the metabolic response …

Vascular endothelial growth factor serum concentrations in hypercholesterolemic patients

Objective. Vascular endothelial growth factor (VEGF) promotes normal and pathological angiogenesis. VEGF is a chemotactic factor for macrophages and vascular smooth muscle cells, and induces synthesis of metalloproteinases and adhesion molecules. VEGF expression is regulated by hypoxia, cytokines, oncogenes, and oxidized low‐density lipoprotein (LDL). The purpose of this study was to determine the relationship between levels of lipid parameters and VEGF, to investigate whether pravastatin treatment influences VEGF serum concentrations, and to examine the relationship between VEGF and the variations in post‐treatment lipid and inflammatory parameters. Material and methods. Eighteen patients aged 48±6.8 years with total cholesterol (TC) >6.1 mmol/L comprised the hypercholesterolemic group. The controls included 12 individuals aged 50±7.4 years with TC <5.1 mmol/L. TC, high‐density lipoprotein cholesterol (HDLC), triglycerides, LDLC, C‐reactive protein (CRP), and VEGF were determined in both groups at baseline, and in the hypercholesterolemic group after 4 months of treatment with 20 mg/day pravastatin. Results. A significant correlation was observed between concentrations of VEGF and TC, LDLC and TG, and a significant difference in VEGF concentration was observed between the control group (mean 142 ng/L) and the hypercholesterolemic group (mean 272.9 ng/L). A significant decrease was observed in TC (14.7 %), LDLC (21.5 %), CRP (22.7 %), and VEGF (14.8 %) after 4 months of treatment with pravastatin. Conclusions. A relationship was found between serum levels of VEGF and most atherogenic lipoproteins. In patients with hypercholesterolemia treated with pravastatin, a reduction in VEGF and CRP was seen in addition to lipid decreases.

Ginger extract components suppress induction of chemokine expression in human synoviocytes.

Ginger has a long history of medicinal use, particularly as an anti-inflammatory agent for a wide variety of diseases such as arthritis. Suppression of inflammation in arthritis is attributed to suppression of proinflammatory cytokines and chemokines produced by synoviocytes, chondrocytes, and leukocytes. This study aimed to elucidate the effect of a combination ginger extract and its individual components on chemokine expression in human synoviocytes. Human synoviocytes were incubated with 100 microg/mL combination ginger extract (GE) of Alpinia galanga (AG) and Zingiber officinale (ZO); AG extract alone; ZO extract alone; or control media, for 1 hour at 37 degrees C, 5% CO2. Cells were next activated with 1 ng/mL of tumor necrosis factor alpha (TNF-alpha) for 1 hour to determine macrophage chemotactic factor (MCP-1) and interferon-gamma activated protein (IP-10) mRNA levels using reverse transcriptase polymerase chain reaction (RT-PCR). Secreted MCP-1 and IP-10 were quantified by enzyme-linked immunosorbent assay (ELISA) following a 24 hour incubation period. The GE combination was consistently more effective in decreasing chemokine mRNA and chemokine secreted protein levels than its individual components ZO or AG. In comparison, ZO was more effective than AG in suppressing chemokine expression. The present study demonstrates that GE inhibits chemokine expression, and that the combination of ZO and AG components acts synergistically. This ginger formulation may be useful for suppressing inflammation due to arthritis.

Serum exposed to nanoparticle carbon black displays increased potential to induce macrophage migration

Objective: To assess whether fine and ultrafine particles (nanoparticles) have the capacity to activate factors in serum that would induce macrophage migration. This is a model previously reported to investigate complement activation by other respirable particles and fibres. Method: Foetal bovine serum was exposed to varying doses of fine and nanoparticle carbon black as well as the oxidant tert-butyl hydroperoxide ( tBHP). The subsequent potential of the serum to induce macrophage migration was measured using a macrophage chemotaxis assay. Results: Treatment of serum with 10 mg/ml of nanoparticle carbon black generated substances that induced a 1.8-fold increase in macrophage migration ( P < 0.001) compared with untreated serum. This effect was partially inhibited by antioxidant intervention. Serum treated with an equivalent mass of fine carbon black did not display any chemotactic potential. tBHP treatment of the serum did not result in the generation of macrophage chemotactic factors. Conclusions: High doses of nanoparticle carbon black have the capacity to cause chemotactic factor generation in serum, by a mechanism involving ROS generation, although ROS alone, in the form of tBHP are not adequate to generate chemotactic factors in serum.