Inhibition Of Macrophage Infiltration Research Articles

Brazilin Ameliorates Diabetic Nephropathy and Inflammation in db/db Mice.

Hyperglycemia and inflammation play important roles in the pathogenesis of diabetic nephropathy (DN). Brazilin might be an effective pharmacological agent against hyperglycemia and inflammation. In our present study, we explored whether brazilin mitigated pathological progression, inflammation, and extracellular matrix (ECM) accumulation in a mouse model of diabetic nephropathy. Brazilin reduced aggravated biochemical indices of DN (proteinuria and the serum glucose level) and renal hypertrophy. Brazilin also improved renal morphology and inhibited macrophage infiltration, as manifested by different pathological staining methods. Brazilin reduced the levels of pro-inflammatory cytokines and CD68, a macrophage marker, in the kidney cortex, as revealed by both RT-PCR and western blotting experiments. Furthermore, brazilin significantly downregulated the serum levels of pro-inflammatory cytokines and chemokines. Interestingly, brazilin significantly upregulated the levels of the anti-inflammatory factor IL-10, and prevented ECM accumulation. Brazilin reduced nuclear translocation of the NF-κB p65 subunit both in vitro and in vivo. Thus, brazilin might be a useful treatment for DN, through mitigating hypoglycemia, inflammation, and ECM accumulation.

Pirfenidone ameliorates murine chronic GVHD through inhibition of macrophage infiltration and TGF-β production

AbstractAllogeneic hematopoietic stem cell transplantation is hampered by chronic graft-versus-host disease (cGVHD), resulting in multiorgan fibrosis and diminished function. Fibrosis in lung and skin leads to progressive bronchiolitis obliterans (BO) and scleroderma, respectively, for which new treatments are needed. We evaluated pirfenidone, a Food and Drug Administration (FDA)-approved drug for idiopathic pulmonary fibrosis, for its therapeutic effect in cGVHD mouse models with distinct pathophysiology. In a full major histocompatibility complex (MHC)-mismatched, multiorgan system model with BO, donor T-cell responses that support pathogenic antibody production are required for cGVHD development. Pirfenidone treatment beginning one month post-transplant restored pulmonary function and reversed lung fibrosis, which was associated with reduced macrophage infiltration and transforming growth factor-β production. Pirfenidone dampened splenic germinal center B-cell and T-follicular helper cell frequencies that collaborate to produce antibody. In both a minor histocompatibility antigen–mismatched as well as a MHC-haploidentical model of sclerodermatous cGVHD, pirfenidone significantly reduced macrophages in the skin, although clinical improvement of scleroderma was only seen in one model. In vitro chemotaxis assays demonstrated that pirfenidone impaired macrophage migration to monocyte chemoattractant protein-1 (MCP-1) as well as IL-17A, which has been linked to cGVHD generation. Taken together, our data suggest that pirfenidone is a potential therapeutic agent to ameliorate fibrosis in cGVHD.

Berberine alleviates dextran sodium sulfate-induced colitis by improving intestinal barrier function and reducing inflammation and oxidative stress.

Berberine has demonstrated efficacy in alleviating experimental colitis in vivo and in vitro. However, the anti-colitis mechanisms of berberine that enable it to promote intestinal barrier function in vivo remain unclear. The present study aimed to evaluate the effect of berberine on intestinal epithelial barrier function, expression of tight junction proteins and the levels of inflammatory and oxidative stress factors in the intestinal mucosa of dextran sulfate sodium (DSS)-induced colitis mice. Berberine (100 mg/kg) was administered for five days to mice with established colitis, induced by administration of DSS (3% w/v) for six days. Intestinal barrier function and the presence of proinflammatory factors, oxidative stress and active signaling pathways in the colon were determined principally by western blotting and reverse transcription-quantitative polymerase chain reaction. It was observed that berberine reduced weight loss, shortening of the colon and colon damage in DSS-colitis mice. In addition, berberine significantly inhibited the increase of fluorescein isothiocyanate-dextran in serum and the decrease of zonula occluden-1 (also known as tight junction protein-1), occludin and epithelial cadherin expression in colonic tissue, relative to a DSS-treated control group. Berberine also significantly inhibited the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α mRNA and phosphorylation of signal transducer and activator of transcription 3. Furthermore, berberine reduced the levels of myeloperoxidase and increased the levels of superoxide dismutase and catalase in colon and serum samples relative to the control group. The expression of cluster of differentiation 68 in the colon of colitis mice was also reduced by berberine. Collectively, these data suggest that berberine alleviates colitis principally by improving intestinal barrier function and promoting anti-inflammatory and antioxidative stress responses. In turn these effects inhibit macrophage infiltration into the colon and thus may be central to the anti-colitis activity of berberine.

Endothelial Specific Molecule 1 (Esm‐1) Inhibits Macrophage Infiltration in a Mouse Model of Goodpasture's Syndrome

Goodpasture's syndrome is an autoimmune disorder caused by pathogenic antibodies to kidney and lung basement membranes causing acute kidney and lung injury, respectively. We modeled this syndrome by treatment with anti‐GBM (Glomerular Basement Membrane) antibodies leading to glomerular and tubulointerstitial inflammation in mice. Endothelial Specific Molecule1 (Esm‐1)/endocan is a secreted glycoprotein highly expressed in kidney glomeruli and lung endothelium and is proposed to disrupt molecular interactions that mediate leukocyte infiltration and anti‐GBM nephritis. To discover the in vivo functional role of Esm‐1 in leukocyte infiltration in anti‐GBM mice, we delivered Esm‐1 plasmid for stable integration to anti‐GBM mice and controls by hydrodynamic tail vein injection. We quantified kidney leukocyte infiltration by separating glomerular and tubulointerstitial compartments, dissociating into single cells, and measuring leukocyte subtypes by flow cytometry. In contrast to i.p. administration of recombinant Esm‐1 which has an abbreviated half‐life in mouse serum (less than 2 hours), we induced ~12‐fold increase in circulating Esm‐1 that persists for 2 weeks compared to control injected mice, by hydrodynamic injection of an Esm‐1‐expressing plasmid (11242 +/− 3324 vs. 958 +/− 188 pg/mL, p<0.05, N=3–5/group). We demonstrate that by flow cytometry, anti‐GBM mice show significantly increased glomerular (3.4 +/− 0.47% vs. 1.1 +/− 0.33%, p < 0.01, N=8/group) and tubulointerstitial (1.4 +/− 0.14% vs. 0.1+/− 0.032%, p < 0.01, N=8/group) CD45+ leukocytes seven days post treatment with anti‐GBM antisera. The increase in CD45+ cells includes increased glomerular (3.4 +/− 0.47% vs. 1.1 +/− 0.33%, p < 0.01) and tubular (1.2 +/− 0.14% vs. 0.1+/− 0.025%, p < 0.01) macrophages. By increasing circulating Esm‐1, we significantly decreased macrophage infiltration in the tubulointerstitium (4.2 ± 1.3% vs. 1.6 ± 0.4%, P < 0.01), but did not influence glomerular macrophage infiltration (2.3 ± 1.2% vs. 1.5 ± 0.2%, P = 0.13). Furthermore, Esm‐1 does not alter kidney neutrophils (glomerular: 0.013 ± 0.007% vs. 0.010 ± 0.006%, p = 0.61; tubulointerstitial: 0.19 ± 0.02% vs. 0.27 ± 0.07%, p = 0.085) or lymphocytes(glomerular: 1.7 ± 0.8% vs. 1.9 ± 0.9%, p = 0.89; tubulointerstitial: 1.9 ± 0.70% vs. 2.2 ± 0.71%, p = 0.64). We also found that inhibition of macrophage infiltration was dependent on glycosylation of Esm‐1. Furthermore, we have generated Esm‐1 knockout mice for complementary studies. We conclude that in contrast to deletion of the inflammatory mediator ICAM‐1, Esm‐1 inhibits inflammation in a tissue and cell‐specific manner. Esm‐1 provides a natural biologic inhibitor of inflammation, and based on its expression pattern, may be a key therapeutic target in pulmonary‐renal syndromes.Support or Funding Information1. Larry L. Hillblom Foundation2. Holmgren Family3. NIDDK

Macrophages and tumor progression: on the way to macrophage-specific therapy

According to the current paradigm proposed by Piter Novell [1], carcinogenesis is a process of clonal evolution in which consequent cycles of clonal selection in the adaptive tissue microenvironment give rise to tumors with a variety of genetic and other molecular changes determining the biological behavior of each individual tumor. Selection of clones with different properties provides heterogeneity of cancer cells within one tumor and thus results in a low effectiveness of chemotherapy. On the average, only 40–60% of cancer patients respond to chemotherapy, and even in the case of complete regression, there is a high probability of tumor recurrence [2, 3]. Increasing the effectiveness of solid tumor therapy and reducing the possibility of recurrence requires not only the use of optimal individual schemes of therapy for each patient, but also the development of combined approaches aimed at both the destruction of tumor cells and antitumor programming of the microenvironment, where immune cells plays a prominent regulatory role. The key cells of the immune system that determine the relationship between tumor cells and the microenvironment, from early stages of tumor growth, including the regulation of neoangiogenesis, and to terminal stage of dissemination of malignant process, are tumor-associated macrophages (TAM) [4– 6]. Identification of the pathways responsible for the tumor-supporting function of macrophages makes it possible to develop therapeutic approaches combining chemotherapy with the macrophage blocking strategy. Inhibition of macrophage infiltration into tumor, their removal with anti-macrophagal agents, and switching off the function of the macrophage colony-stimulating factor can be the macrophage blocking tools. Approaches of simultaneous alteration of cancer stem cells and TAM to abolish chemoresistance and inhibit tumor progression are promising. Strategies for reprogramming of macrophages to switch off towards the antitumor phenotype are developing. Thus, an extremely wide range of regulatory and effector activity and high functional plasticity of macrophages promise the development of macrophage-targeted therapeutic agents to modulate relationships between tumor and microenvironment to prevent the tumor progression.

Paeoniflorin prevents TLR2/4-mediated inflammation in type 2 diabetic nephropathy

Paeoniflorin is an effective Chinese traditional medicine with anti-inflammatory and immune-regulatory effects. The aim of this study was to investigate the underlying renoprotective mechanism of Paeoniflorin. In vivo, db/db mice were intraperitoneally injected with Paeoniflorin at a dose of 15, 30, or 60 mg/kg respectively. The immunostaining of TLR2, TLR4, CD68, NF-kB p65 and the mRNA level of inflammatory factors, together with the protein expression of TLR2/4 signaling were evaluated. Our data demonstrated that Paeoniflorin could decrease the urinary albumin excretion rate and inhibit macrophage infiltration and activation through blockage of the TLR2/4 signaling pathway compared with the db/db group in vivo. In vitro, RAW264.7 cells were categorized into control, bovin serum albumin (BSA)-stimulated, advanced glycation end products (AGEs)-stimulated, Paeoniflorin intervention and oxidized phospholipid (OxPAPC)-inhibited groups. The cell viability, the optimal stimulated time and concentration were measured as well as the TLR2/4 signaling activation determined by RT-PCR, Western blot and ELISA. Our data demonstrated that Paeoniflorin reduced the AGEs-induced TLR2/4 activation and inflammatory responses, which was consistent with the TLR2/4 inhibitor group. These findings indicate that Paeoniflorin prevents macrophage activation via inhibition of TLR2/4 signaling expression in type 2 diabetic nephropathy.

Flavonoid-enriched extract from Hippophae rhamnoides seed reduces high fat diet induced obesity, hypertriglyceridemia, and hepatic triglyceride accumulation in C57BL/6 mice

Context: Flavonoid-enriched extract from Hippophae rhamnoides L. (Elaeagnaceae) seed (FSH) has shown beneficial effects in anti-hypertension and lowering cholesterol level. However, evidence for its efficacy in treating obesity is limited. Objective: We sought to determine if FSH can reduce body weight and regulate lipid metabolism disorder in high fat diet (HFD)-induced obese mouse model, and to investigate potential molecular targets involved. Materials and methods: C57BL/6 mice were fed with HFD for 8 weeks to induce obesity. The modeled mice were divided into four groups and treated with vehicle, rosiglitazone (2 mg/kg), low (100 mg/kg) and high (300 mg/kg) dose of FSH, respectively. Normal control was also used. The treatments were administered orally for 9 weeks. We measured the effect of FSH on regulating body weight, various liver and serum parameters, and molecular targets that are key to lipid metabolism. Results: FSH administration at 100 and 300 mg/kg significantly reduced body weight gain by 33.06 and 43.51%, respectively. Additionally, triglyceride concentration in serum and liver were decreased by 15.67 and 49.56%, individually, after FSH (300 mg/kg) treatment. Upon FSH (100 and 300 mg/kg) treatment, PPARα mRNA expression was upregulated in liver (1.24- and 1.42-fold) and in adipose tissue (1.66- and 1.72-fold). Furthermore, FSH downregulated PPARγ protein level both in liver and adipose tissue. Moreover, FSH inhibited macrophage infiltration into adipose tissues, and downregulated TNFα mRNA expression in adipose tissue (38.01–47.70%). Conclusion: This effect was mediated via regulation of PPARγ and PPARα gene expression, and suppression of adipose tissue inflammation.

Combination of metformin and VSL#3 additively suppresses western-style diet induced colon cancer in mice

Western-style diet (WD) and dysbiosis are known to be associated with colonic inflammation, which contributes to carcinogenesis. Metformin (Met) exerts anti-inflammatory effects to induce AMP-activated protein kinase (AMPK), resulting in suppressed protein synthesis and reduced cell proliferation. Probiotic VSL#3 (V) modifies microbial composition. We investigated the chemopreventive mechanisms of Met and V in WD-induced colitis-associated colon carcinogenesis. Male BALB/c mice were randomly divided into five groups: a control diet (CD) group, WD group, WD+ Met (250mg/kg/day) group, WD+V (1.3 million bacteria/day) group, and WD+Met+V group. All mice were exposed to azoxymethane (10mg/kg) followed by 2% dextran sodium sulfate (DSS) for 7 days. Using HCT-116 human colon cancer cell line, expression of AMPK, extracellular signal-regulated kinase (ERK), cyclin D1, and Bcl-2 was investigated and cell cycle arrest was assessed. WD enhanced the severity of colitis and tumor growth compared with CD. The combination of Met and V significantly ameliorated colitis and tumor growth by inhibiting macrophage infiltration and maintaining epithelial integrity. In vitro assays showed that the combination therapy promoted late apoptosis by inhibiting cyclin D1 and Bcl-2 and activating pro-apoptotic ERK. A combination therapy with Met and V attenuates tumor growth in a mouse model of WD-induced colitic cancer, suggesting that this strategy could be useful for the chemoprevention of colon cancer.

Macrophage/monocyte-specific deletion of Ras homolog gene family member A (RhoA) downregulates fractalkine receptor and inhibits chronic rejection of mouse cardiac allografts

The cellular and molecular mechanisms of chronic rejection of transplanted organs remain obscure; however, macrophages are known to play a critical role in the injury and repair of allografts. Among multiple factors influencing macrophage infiltration to allografts, the fractalkine chemokine (C-X3-C motif) ligand 1(CX3CL1)/chemokine (C-X3-C motif) receptor 1 (CX3CR1) signaling pathway and actin cytoskeleton, which is regulated by a small guanosine-5׳-triphosphatase Ras homolog gene family member A (RhoA), are of the utmost importance. To define the role of macrophage/RhoA pathway involvement in chronic rejection, we generated mice with monocyte/macrophage-specific deletion of RhoA. Hearts from BALB/c (H-2d) donors were transplanted into RhoAflox/flox (no Cre) and heterozygous Lyz2Cre+/-RhoAflox/flox recipients treated with cytotoxic T-lymphocyte-associated protein 4 immunoglobulin to inhibit early T-cell response. Allografts were assessed for chronic rejection and monocyte/macrophage functions. The deletion of RhoA inhibited macrophage infiltration, neointimal hyperplasia of vasculature, and abrogated chronic rejection of the allografts. The RhoA deletion downregulated G protein-coupled fractalkine receptor CX3CR1, which activates the RhoA pathway and controls monocyte/macrophage trafficking into the vascular endothelium. This in turn promotes, through overproliferation and differentiation of smooth muscle cells in the arterial walls, neointimal hyperplasia. Our finding of codependence of chronic rejection on monocyte/macrophage CX3CR1/CX3CL1 and RhoA signaling pathways may lead to the development of novel anti-chronic rejection therapies.

Patchouli alcohol attenuates experimental atherosclerosis via inhibiting macrophage infiltration and its inflammatory responses.

Patchouli alcohol (PA) is a tricyclic sesquiterpene extracted from a traditional Chinese herb pogostemonis herba. Literatures have proven that PA could inhibit inflammatory responses in various inflammatory disease models. However, whether PA could protect against atherosclerosis, a chronic vascular inflammation, is unknown. In this study, we sought to explore this issue in atherosclerosis-prone apolipoprotein E knockout mice fed an atherogenic diet, with or without daily PA intragastrical administration (40mg/kg). Our results showed that PA administration did not change plasma lipids metabolism, however, it significantly attenuated atherosclerotic plaque burdens in both the aorta and the aortic root. The lesional macrophage content, shown as Mac2 positive areas, was reduced, while the lesional smooth muscle cell and collagen content, shown as α-SMA positive areas and by Sirius red staining, respectively, was not affected in PA-treated mice, compared with non-treated controls. Aortic mRNA expression of macrophage inflammatory cytokines, including MCP-1, iNOS, IL-1β, IL-6, CXCL9 and CXCL11, was also reduced in PA-treated mice. Therefore, we demonstrated that PA could attenuate atherosclerosis, possibly by inhibiting macrophage infiltration and its inflammatory responses.

Emodin Inhibits Breast Cancer Growth by Blocking the Tumor-Promoting Feedforward Loop between Cancer Cells and Macrophages.

Macrophage infiltration correlates with severity in many types of cancer. Tumor cells recruit macrophages and educate them to adopt an M2-like phenotype through the secretion of chemokines and growth factors, such as MCP1 and CSF1. Macrophages in turn promote tumor growth through supporting angiogenesis, suppressing antitumor immunity, modulating extracellular matrix remodeling, and promoting tumor cell migration. Thus, tumor cells and macrophages interact to create a feedforward loop supporting tumor growth and metastasis. In this study, we tested the ability of emodin, a Chinese herb-derived compound, to inhibit breast cancer growth in mice and examined the underlying mechanisms. Emodin was used to treat mice bearing EO771 or 4T1 breast tumors. It was shown that emodin attenuated tumor growth by inhibiting macrophage infiltration and M2-like polarization, accompanied by increased T-cell activation and reduced angiogenesis in tumors. The tumor inhibitory effects of emodin were lost in tumor-bearing mice with macrophage depletion. Emodin inhibited IRF4, STAT6, and C/EBPβ signaling and increased inhibitory histone H3 lysine 27 tri-methylation (H3K27m3) on the promoters of M2-related genes in tumor-associated macrophages. In addition, emodin inhibited tumor cell secretion of MCP1 and CSF1, as well as expression of surface anchoring molecule Thy-1, thus suppressing macrophage migration toward and adhesion to tumor cells. These results suggest that emodin acts on both breast cancer cells and macrophages and effectively blocks the tumor-promoting feedforward loop between the two cell types, thereby inhibiting breast cancer growth and metastasis. Mol Cancer Ther; 15(8); 1931-42. ©2016 AACR.

NF-κB decoy oligodeoxynucleotide mitigates wear particle-associated bone loss in the murine continuous infusion model

Total joint replacement is a cost-effective surgical procedure for patients with end-stage arthritis. Wear particle-induced chronic inflammation is associated with the development of periprosthetic osteolysis. Modulation of NF-κB signaling in macrophages, osteoclasts, and mesenchymal stem cells could potentially mitigate this disease. In the current study, we examined the effects of local delivery of decoy NF-κB oligo-deoxynucleotide (ODN) on wear particle-induced bone loss in a murine continuous femoral particle infusion model. Ultra-high molecular weight polyethylene particles (UHMWPE) with or without lipopolysaccharide (LPS) were infused via osmotic pumps into hollow titanium rods placed in the distal femur of mice for 4weeks. Particle-induced bone loss was evaluated by μCT, and immunohistochemical analysis of sections from the femur. Particle infusion alone resulted in reduced bone mineral density and trabecular bone volume fraction in the distal femur. The decoy ODN reversed the particle-associated bone volume fraction loss around the implant, irrespective of the presence of LPS. Particle-infusion with LPS increased bone mineral density in the distal femur compared with particle-infusion alone. NF-κB decoy ODN reversed or further increased the bone mineral density in the femur (3–6mm from the distal end) exposed to particles alone or particles plus LPS. NF-κB decoy ODN also inhibited macrophage infiltration and osteoclast number, but had no significant effects on osteoblast numbers in femurs exposed to wear particles and LPS. Our study suggests that targeting NF-κB activity via local delivery of decoy ODN has great potential to mitigate wear particle-induced osteolysis. Statement of SignificanceTotal joint replacement is a cost-effective surgical procedure for patients with end-stage arthritis. Chronic inflammation is crucial for the development of wear particle-associated bone loss. Modulation of NF-κB signaling in macrophages (pro-inflammatory cells), osteoclasts (bone-resorbing cells), and osteoblasts (bone-forming cells) could potentially mitigate this disease. Here we demonstrated that local delivery of decoy NF-κB oligo-deoxynucleotide (ODN) mitigated ultra-high molecular weight polyethylene (UHMWPE) wear particle induced bone loss in a clinically relevant murine model. The protective effects of decoy ODN was associated with reduced macrophage infiltration and osteoclast activation, but had no significant effects on osteoblast numbers. Our study suggests that targeting NF-κB activity via local delivery of decoy ODN has great potential to mitigate wear particle-induced bone loss.

Ninjurin1 inhibits colitis-mediated colon cancer development and growth by suppression of macrophage infiltration through repression of FAK signaling.

Macrophage infiltration promotes tumorigenesis. However, the macrophage infiltration regulatory molecules have not been fully determined. Nerve injury-induced protein 1 (ninjurin1) is a homophilic cell surface adhesion molecule that plays an important role in cell migration and attachment. Although ninjurin1 is believed to play a role in several malignancies, it is unclear whether ninjurin1 expression contributes to cancer progression. We used transgenic mice (tg mice) that overexpressed ninjurin1 on macrophages. We subjected ninjurin1 tg mice to a well-known mouse model of colitis-associated colon cancer in which animals are treated with azoxymethane (AOM) and dextran sulfate sodium (DSS). After AOM and DSS treatment, ninjurin1 tg mice developed fewer and smaller tumors compared with wild-type (wt) mice. Ninjurin1 tg mice also showed reduced infiltration of macrophages and suppressed angiogenesis in the tumor mass. We therefore explored whether ninjurin1 decreases macrophage migration into the tumor sites. After adoptive transfer to tumor-bearing recipients, wild type and ninjurin1 tg mice's peritoneal macrophages were freshly isolated and labeled with carboxyfluorescein succinimidyl ester (CFSE). As expected, compared with that of wt type macrophages, tumor infiltration of ninjurin1-overexpressing macrophages was significantly decreased. We also found that ninjurin1 overexpression suppressed FAK activity. In addition, knockdown of ninjurin1 enhanced FAK activity and migration activity of RAW264.7 cells. Ninjurin1 overexpression on macrophage inhibits tumor growth by suppression of macrophage infiltration through repression of FAK signaling. Ninjurin1 is a key regulator molecule for macrophage migration and Tumor-associated macrophages (TAM) mediated tumorigenesis in vivo.

Hydroxycinnamic acid derivatives: a potential class of natural compounds for the management of lipid metabolism and obesity.

Hydroxycinnamic acid derivatives are important class of polyphenolic compounds originated from the Mavolanate-Shikimate biosynthesis pathways in plants. Several simple phenolic compounds such as cinnamic acid, p-coumaric acid, ferulic acid, caffeic acid, chlorgenic acid, and rosmarinic acid belong to this class. These phenolic compounds possess potent antioxidant and anti-inflammatory properties. These compounds were also showed potential therapeutic benefit in experimental diabetes and hyperlipidemia. Recent evidences also suggest that they may serve as valuable molecule for the treatment of obesity related health complications. In adipose tissues, hydroxycinnamic acid derivatives inhibit macrophage infiltration and nuclear factor κB (NF-κB) activation in obese animals. Hydroxycinnamic acid derivatives also reduce the expression of the potent proinflammatory adipokines tumor necrosis factor-α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor type-1 (PAI-1), and they increase the secretion of an anti-inflammatory agent adiponectin from adipocytes. Furthermore, hydroxycinnamic acid derivatives also prevent adipocyte differentiation and lower lipid profile in experimental animals. Through these diverse mechanisms hydroxycinnamic acid derivatives reduce obesity and curtail associated adverse health complications.

Dorsal Root Ganglion Infiltration by Macrophages Contributes toPaclitaxel Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a disruptive and persistent side effect of cancer treatment with paclitaxel. Recent reports showed that paclitaxel treatment results in the activation of Toll-like receptor 4 (TLR4) signaling and increased expression of monocyte chemoattractant protein 1 (MCP-1) in dorsal root ganglion cells. In this study, we sought to determine whether an important consequence of this signaling and also a key step in the CIPN phenotype was the recruitment and infiltration of macrophages into dorsal root ganglia (DRG). Here, we show that macrophage infiltration does occur in a time course that matches the onset of the behavioral CIPN phenotype in Sprague-Dawley rats. Moreover, depletion of macrophages by systemic administration of liposome-encapsulated clodronate (clophosome) partially reversed behavioral signs of paclitaxel-induced CIPN as well as reduced tumor necrosius factor α expression in DRG. Intrathecal injection of MCP-1 neutralizing antibodies reduced paclitaxel-induced macrophage recruitment into the DRG and also blocked the behavioral signs of CIPN. Intrathecal treatment with the TLR4 antagonist lipopolysaccharide-RS (LPS-RS) blocked mechanical hypersensitivity, reduced MCP-1 expression, and blocked the infiltration of macrophages into the DRG in paclitaxel-treated rats. The inhibition of macrophage infiltration into DRG after paclitaxel treatment with clodronate or LPS-RS prevented the loss of intraepidermal nerve fibers (IENFs) observed after paclitaxel treatment alone. These results are the first to indicate a mechanistic link such that activation of TLR4 by paclitaxel leads to increased expression of MCP-1 by DRG neurons resulting in macrophage infiltration to the DRG that express inflammatory cytokines and the combination of these events results in IENF loss and the development of behavioral signs of CIPN. This paper shows that activation of innate immunity by paclitaxel results in a sequence of signaling events that results in the infiltration of the dorsal root ganglia by activated macrophages. Macrophages appear to drive the development of behavioral hypersensitivity and the loss of distal epidermal nerve fibers, and hence play an important role in the mechanism of paclitaxel-related neuropathy.

99Tc-MDP treatment for the therapy of rheumatoid arthritis, choroidal neovascularisation and Graves' ophthalmopathy.

Technetium 99 conjugated with methylene diphosphonate, which is an anti-inflammatory drug, can inhibit macrophage infiltration and downregulate a number of proinflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β. Recently, numerous studies have indicated that it could improve rheumatoid arthritis (RA) activity by upregulating the frequency of peripheral γδ T cells and cluster of differentiation CD4+CD25+Foxp3+ Tregs, affecting the serum cytokine environment, inhibiting osteoclast formation and reducing the concentrations of rheumatoid factor-immunoglobulin M (IgM)/IgG/IgA. As well, it may have a therapeutic role for choroidal neovascularisation (CNV) and Graves' ophthalmopathy (GO). Therefore, it will be a valuable choice in the treatment of RA, CNV and GO.

Priming with erythropoietin enhances cell survival and angiogenic effect of mesenchymal stem cell implantation in rat limb ischemia

IntroductionBone marrow mesenchymal stem cells (BMMSCs) ameliorate tissue damage after ischemic injury. Erythropoietin (Epo) has pleiotropic effects in addition to hematopoietic activity. The aim of this study was to investigate whether Epo enhanced cell survival and angiogenic effect of BMMSC implantation in rat limb ischemia model.Methods and resultsMSCs were isolated from BM in GFP-transgenic rats. In a culture study, Epo promoted BMMSC proliferation in normoxia and enhanced cell survival under the culture condition mimicking ischemia (1% oxygen and nutrient deprivation). BMMSCs with and without 48 h of pretreatment by Epo (80 IU/ml) were locally administered to rat hindlimb ischemia models in vivo. At 3 days after implantation, BMMSC engraftment in the perivascular area of the injured muscle was significantly higher in the cells preconditioned with Epo than in the cells without preconditioning. Stromal derived factor-1α and fibroblast growth factor-2 expressions were detected in the engrafted BMMSCs. At 14 days after implantation, the Epo-preconditioned BMMSCs significantly promoted blood perfusion and capillary growth compared to the controls in laser Doppler and histological studies. In addition to promoting neovascularization, the Epo-preconditioned BMMSCs significantly inhibited macrophage infiltration in the perivascular area.ConclusionEpo elicited pro-survival potential in the BMMSCs. Pharmacological cell modification with Epo before implantation may become a feasible and promising strategy for improving current therapeutic angiogenesis with BMMSCs.

OXYGEN MITIGATES THE INFLAMMATORY RESPONSE IN A MODEL OF HEMORRHAGE AND ZYMOSAN-INDUCED INFLAMMATION.

Sequential insults (hits) may change the inflammatory reaction that develops in response to separate single hits (e.g., injury, infection); however, their effects on the long-term clinical outcome are still only partially elucidated. Double-hit models are typically severe and fatal. We characterized in C57BL/6 mice a moderate double-hit model of hemorrhage (35%-40% of total blood volume) and resuscitation, followed by peritoneal injection of zymosan A that induced local and systemic inflammation with 58% mortality. This model allowed exploration of the inflammatory response over time in the surviving mice. We show that after 2 days, mice subjected to the double-hit model had elevated proinflammatory systemic and local peritoneal cytokine response (interleukin [IL]-1β, tumor necrosis factor-α, IL-6) and moderately elevated anti-inflammatory cytokines (IL-10, transforming growth factor-β), compared with the single-hit and sham mice. However, this dynamically changed, and by day 7, proinflammatory cytokines were reduced, and anti-inflammatory cytokines were markedly (P < 0.05) elevated in the double-hit group. Mice in the double-hit group that inhaled 100% oxygen intermittently for 6 h every day exhibited markedly reduced serum proinflammatory cytokines as early as day 2 (P < 0.05), inhibited macrophage infiltration into the peritoneum (by 13-fold; P < 0.05), and substantially increased survival rates of 85% (P = 0.00144). Oxygen mitigates the inflammatory response and exerts a beneficial effect on survival in a double-hit model of hemorrhage and zymosan-induced inflammation.

Sorafenib Inhibits Renal Fibrosis Induced by Unilateral Ureteral Obstruction via Inhibition of Macrophage Infiltration

Aims: Sorafenib, which has been used extensively for the treatment of renal cell cancer and advanced hepatocellular carcinoma (HCC), has also been shown to have antifibrotic effects in liver fibrosis. However, the effects of sorafenib on renal fibrosis are unknown. Therefore, we investigated whether sorafenib inhibited renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO) and further explored the potential mechanism. Methods: Mice underwent UUO followed by vehicle or sorafenib treatment. The expression of CD68, a macrophage marker, and the pro-inflammatory cytokines, MCP1 and CXCR3, were immunohistochemically analyzed. The involvement of macrophages in the formation of renal fibrosis was studied using confocal microscopy. Results: Renal histopathology improved in the UUO-sorafenib mice. Sorafenib notably suppressed TGF-β1-mediated renal fibrogenic effects. The mRNA and protein expressions of CD68, MCP1, and CXCR3 in the obstructed kidney were significantly decreased by sorafenib. Immunohistochemistry showed that CD68 and CXCR3 had a similar distribution, whereas MCP1 was observed predominantly in the tubular epithelial cells. Double immunofluorescence demonstrated that CD68-positive macrophages could co-localize with CXCR3. It also revealed that CXCR3 interacted with CXCL11 in the UUO mouse kidneys. Widespread adhesion of macrophages to myofibroblasts was markedly inhibited in UUO-sorafenib mouse kidneys. Conclusions: Taken together, the results indicated that sorafenib had protective effects against renal fibrosis; its mechanism of action was associated with inhibition of macrophage infiltration via the CXCR3/CXCL11 pathway. These data suggest the clinical potential of sorafenib for treatment of renal fibrosis and illustrate the immunological mechanisms underlying the protective effects of sorafenib.

Preventive Effect of Salicylate and Pyridoxamine on Diabetic Nephropathy

Objective. Diabetic nephropathy is a life-threatening complication in patients with long-standing diabetes. Hemodynamic, inflammatory, and metabolic factors are considered as developmental factors for diabetic nephropathy. In this study, we evaluated whether pharmacological interventions with salicylate, compared to pyridoxamine, could prevent diabetic nephropathy in mice. Methods. Male mice overexpressing inducible nitric oxide synthase in pancreatic β-cells were employed as a diabetic model. Salicylate (3 g/kg diet) or pyridoxamine (1 g/L drinking water; ~200 mg/kg/day) was given for 16 weeks to assess the development of diabetic nephropathy. Treatment with long-acting insulin (Levemir 2 units/kg twice a day) was used as a control. Results. Although higher blood glucose levels were not significantly affected by pyridoxamine, early to late stage indices of nephropathy were attenuated, including kidney enlargement, albuminuria, and increased serum creatinine, glomerulosclerosis, and inflammatory and profibrotic gene expressions. Salicylate showed beneficial effects on diabetic nephropathy similar to those of pyridoxamine, which include lowering blood glucose levels and inhibiting macrophage infiltration into the kidneys. Attenuation of macrophage infiltration into the kidneys and upregulation of antiglycating enzyme glyoxalase 1 gene expression were found only in the salicylate treatment group. Conclusions. Treatment with salicylate and pyridoxamine could prevent the development of diabetic nephropathy in mice and, therefore, would be a potentially useful therapeutic strategy against kidney problems in patients with diabetes.