Induced Macrophage Infiltration Research Articles

E2F-mediated POLA2 upregulation is correlated with macrophage infiltration and poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the major histological type of primary liver cancer with a relatively poor prognosis, because most HCC cases are usually diagnosed at an advanced stage. Thus, it is essential to explore novel candidate biomarkers for early diagnosis and prognosis predication of HCC. HCC transcription sequencing data were downloaded and analyzed. POLA2 expression pattern was characterized in tumor development process. POLA2 expression was evaluated by western blotting. Kaplan-Meier plot was utilized to evaluate POLA2's ability for prognosis predication. Correlation analysis and enrichment analysis were performed to explore the functional role of POLA2 in HCC development. Knockdown of E2F1 or E2F4 was used to evaluate their ability in regulating POLA2 expression. CYBERSORT (https://cibersortx.stanford.edu/) was used to estimate the infiltration levels of immune cells. POLA2 was overexpressed in HCC. Moreover, western blotting results showed that POLA2 was upregulated by transcription factors E2F1 rather than E2F4 in HCC. POLA2 facilitated cell cycle progression, DNA replication and DNA repair. High POLA2 expression was correlated with poor overall survival in HCC patients. POLA2 induced macrophage infiltration in the tumor microenvironment by upregulating the expression CSF1 and VEGFA expression. POLA2 is a novel diagnostic and prognostic biomarker of HCC with potential clinical value.

Trimethylamine N-oxide promotes abdominal aortic aneurysm by inducing vascular inflammation and vascular smooth muscle cell phenotypic switching

ObjectiveInflammation and vascular smooth muscle cell (VSMC) phenotypic switching are implicated in the pathogenesis of abdominal aortic aneurysm (AAA). Trimethylamine N-oxide (TMAO) has emerged as a crucial risk factor in cardiovascular diseases, inducing vascular inflammation and calcification. We aimed to evaluate the effect of TMAO on the formation of AAA. Approach and resultsHere, we showed that TMAO was elevated in plasma from AAA patients compared with nonaneurysmal subjects by liquid chromatography‒mass spectrometry (LC‒MS) detection. Functional studies revealed that increased TMAO induced by feeding a choline-supplemented diet promoted Ang II-induced AAA formation. Immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and Western blot analyses revealed that TMAO induced macrophage infiltration and inflammatory factor release. Conversely, inhibition of TMAO by supplementation with DMB suppressed AAA formation and the inflammatory response. Molecular studies revealed that TMAO regulated VSMC phenotypic switching. Flow cytometry analyses showed that TMAO induces macrophage M1-type polarization. Furthermore, pharmacological intervention experiments suggested that the nuclear factor-κB (NF-κB) signaling pathway was critical for TMAO to trigger AAA formation. ConclusionsTMAO promotes AAA formation by inducing vascular inflammation and VSMC phenotypic switching through activation of the NF-κB signaling pathway. Thus, TMAO is a prospective therapeutic AAA target.

Tumor-associated macrophages: an effective player of the tumor microenvironment.

Cancer progression is primarily caused by interactions between transformed cells and the components of the tumor microenvironment (TME). TAMs (tumor-associated macrophages) make up the majority of the invading immune components, which are further categorized as anti-tumor M1 and pro-tumor M2 subtypes. While M1 is known to have anti-cancer properties, M2 is recognized to extend a protective role to the tumor. As a result, the tumor manipulates the TME in such a way that it induces macrophage infiltration and M1 to M2 switching bias to secure its survival. This M2-TAM bias in the TME promotes cancer cell proliferation, neoangiogenesis, lymphangiogenesis, epithelial-to-mesenchymal transition, matrix remodeling for metastatic support, and TME manipulation to an immunosuppressive state. TAMs additionally promote the emergence of cancer stem cells (CSCs), which are known for their ability to originate, metastasize, and relapse into tumors. CSCs also help M2-TAM by revealing immune escape and survival strategies during the initiation and relapse phases. This review describes the reasons for immunotherapy failure and, thereby, devises better strategies to impair the tumor-TAM crosstalk. This study will shed light on the understudied TAM-mediated tumor progression and address the much-needed holistic approach to anti-cancer therapy, which encompasses targeting cancer cells, CSCs, and TAMs all at the same time.

Risk factors for fatty pancreas and effects of fatty infiltration on pancreatic cancer.

Objective: This study clarified the risk factors and pathophysiology of pancreatic cancer by examining the factors associated with fatty pancreas. Methods: The degree of fatty pancreas, background factors, and incidence of pancreatic cancer were examined among nonalcoholic fatty liver disease (NAFLD) patients (n = 281) and intraductal papillary mucinous neoplasm (IPMN) patients with a family history of pancreatic cancer (n = 38). The presence of fatty pancreas was confirmed by the pancreatic CT value/splenic CT value ratio (P/S ratio). Immunohistochemical staining was performed on 10 cases with fatty pancreas, confirmed via postoperative pathology. Results: Fatty pancreas occurred in 126 patients (44.8%) in the NAFLD group who were older (p = 0.0002) and more likely to have hypertension (p < 0.0001). The IPMN group had 18 patients (47.4%) with fatty pancreas, included more men than women (p = 0.0056), and was more likely to have patients with hypertension (p = 0.0010). On histological examination, a significant infiltration of adipocytes into the acini from the pancreatic interstitium induced atrophy of the pancreatic parenchyma, and both M1 and M2 macrophages were detected in the area where adipocytes invaded the pancreatic parenchyma. Accumulation of p62 and increased positive staining of NQO1 molecules related to autophagy dysfunction were detected in pancreatic acinar cells in the fatty area, acinar-ductal metaplasia, and pancreatic cancer cells. The rate of p62-positive cell area and that of NQO1-positive cell area were significantly higher in the fatty pancreatic region than those in the control lesion (pancreatic region with few adipocyte infiltration). Furthermore, the rate of p62-positive cell area or that of NQO1-positive cell area showed strong positive correlations with the rate of fatty pancreatic lesion. These results suggest that adipocyte invasion into the pancreatic parenthyme induced macrophage infiltration and autophagy substrate p62 accumulation. High levels of NQO1 expression in the fatty area may be dependent on p62 accumulation. Conclusion: Hypertension was a significant risk factor for fatty pancreas in patients with NAFLD and IPMN. In fatty pancreas, fatty infiltration into the pancreatic parenchyme might induce autophagy dysfunction, resulting in activation of antioxidant proteins NQO1. Thus, patients with fatty pancreas require careful follow-up.

Zika Virus Infection Induces Interleukin-1β-Mediated Inflammatory Responses by Macrophages in the Brain of an Adult Mouse Model.

During the 2015-2016 Zika virus (ZIKV) epidemic, ZIKV-associated neurological diseases were reported in adults, including microcephaly, Guillain-Barre syndrome, myelitis, meningoencephalitis, and fatal encephalitis. However, the mechanisms underlying the neuropathogenesis of ZIKV infection are not yet fully understood. In this study, we used an adult ZIKV infection mouse model (Ifnar1-/-) to investigate the mechanisms underlying neuroinflammation and neuropathogenesis. ZIKV infection induced the expression of proinflammatory cytokines, including interleukin-1β (IL-1β), IL-6, gamma interferon, and tumor necrosis factor alpha, in the brains of Ifnar1-/- mice. RNA-seq analysis of the infected mouse brain also revealed that genes involved in innate immune responses and cytokine-mediated signaling pathways were significantly upregulated at 6 days postinfection. Furthermore, ZIKV infection induced macrophage infiltration and activation and augmented IL-1β expression, whereas microgliosis was not observed in the brain. Using human monocyte THP-1 cells, we confirmed that ZIKV infection promotes inflammatory cell death and increases IL-1β secretion. In addition, expression of the complement component C3, which is associated with neurodegenerative diseases and known to be upregulated by proinflammatory cytokines, was induced by ZIKV infection through the IL-1β-mediated pathway. An increase in C5a produced by complement activation in the brains of ZIKV-infected mice was also verified. Taken together, our results suggest that ZIKV infection in the brain of this animal model augments IL-1β expression in infiltrating macrophages and elicits IL-1β-mediated inflammation, which can lead to the destructive consequences of neuroinflammation. IMPORTANCE Zika virus (ZIKV) associated neurological impairments are an important global health problem. Our results suggest that ZIKV infection in the mouse brain can induce IL-1β-mediated inflammation and complement activation, thereby contributing to the development of neurological disorders. Thus, our findings reveal a mechanism by which ZIKV induces neuroinflammation in the mouse brain. Although we used adult type I interferon receptor IFNAR knockout (Ifnar1-/-) mice owing to the limited mouse models of ZIKV pathogenesis, our conclusions contributed to the understanding ZIKV-associated neurological diseases to develop treatment strategies for patients with ZIKV infection based on these findings.

Abstract 553: SKP2 knockout induces macrophage infiltration in p53/Rb1 null transgenic mouse models of osteosarcoma and drives gene expression correlated with improved survival in patients

Abstract Background: Osteosarcoma (OS) is an aggressive cancer of the bone with a poor prognosis. OS often involve mutations of tumor suppressors RB1 and TP53. One putative proto-oncogene in OS is SKP2, which codes for a substrate-recognition factor of the SCF E3 ubiquitin ligase. We have demonstrated that germline knockout of SKP2 in a pre-clinical transgenic mouse model of OS doubly deficient in Rb1 and Trp53 improved survival, delayed tumorigenesis, reduced malignant cell proliferation, slowed tumor growth, diminished stemness, and induced apoptosis. However, the role that SKP2 plays in OS progression remains unclear. Method: We performed bulk RNA-sequencing on pre-clinical transgenic mouse models of OS. To model OS in mice, we generated a conditional double-knockout line of Trp53 and Rb1 mutations induced in cells of the bone-forming osteoblast lineage via Cre-Lox recombination (“DKO”: Osx1-Cre;Rb1lox/lox;p53lox/lox). We compared this with a triple-knockout model, which additionally features a germline Skp2 knockout (“TKO”: Osx1-Cre;Rb1lox/lox;p53lox/lox;SKP2-/-). We compared tumors from the TKO and DKO models via bulk RNA-sequencing (n=3 per group) to study differential expression and immune infiltration. We used immunohistochemistry (IHC) and quantification to validate differences in immune markers between genotypes. Using the transcriptomic results from the mouse models, we analyzed a human OS patient cohort of 83 participants (NCI TARGET OS) with RNA-seq and clinical data via survival analysis to infer the impact of modulating SKP2 in OS patients. Result: We found a large difference in gene expression between the TKO and DKO models. Surprisingly, we observed a dramatic increase in the expression of genes related to immune microenvironment infiltration in TKO tumors compared to DKO. Macrophage transcriptomic signatures were the strongest signal detected (P&amp;lt;0.001), but significant increases in B cells, endothelial cells and T cell signatures were also observed. IHC also showed macrophage markers were higher in TKO (P = 0.08). In the NCI TARGET OS cohort, high expression of genes up-regulated in TKO was significantly correlated with 5-year overall survival (p=0.02). This effect was driven by macrophage transcriptomic signatures. This finding was supported by an immune microenvironment deconvolution analysis, which showed that macrophages and T cells were associated with improved overall survival in the patient cohort (p=0.01). We are currently performing single-cell RNA-sequencing analysis to study immune infiltration and cellular heterogeneity in more detail. Conclusion: Taken together, our new findings indicate that SKP2 modulation in OS may induce a vigorous anti-tumor immune activation especially in the form of macrophage and lymphocyte infiltration into the tumor microenvironment. Citation Format: Alexander Ferrena, Jichuan Wang, Ranxin Zhang, Rui Yang, David Geller, Bang Hoang, Deyou Zheng. SKP2 knockout induces macrophage infiltration in p53/Rb1 null transgenic mouse models of osteosarcoma and drives gene expression correlated with improved survival in patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 553.

CCL3 aggravates intestinal damage in NEC by promoting macrophage chemotaxis and M1 macrophage polarization.

NEC is a life-threatening gastrointestinal disease in neonates, the pathogenesis of which remains poorly understood. CCL3 levels in intestinal tissue of mice were measured and analyzed. HE staining was used to assess pathological changes in intestinal tissue. FCM was used to detect the proportion and phenotype of macrophages. RNA-seq and RT-PCR were used to evaluate the effect of CCL3 on macrophages. CCL3 was highly expressed in the intestinal tissues of mice with NEC and induced macrophage infiltration. Transcriptome data showed that CCL3 strongly induced a transition in the phenotype of macrophages into a proinflammatory one. Mechanistically, in vivo experiments confirmed that CCL3 induced M1 macrophage polarization in NEC intestinal tissue, thereby aggravating inflammatory injury of intestinal tissue, which was alleviated by anti-CCL3 treatment. In addition, in vitro experiments showed that CCL3 significantly enhances the expression of M1-related genes in both PMφ and BMDM while inhibiting the expression of M2-related genes, which was also alleviated by anti-CCl3 treatment. Our data elucidated the involvement of CCL3 in the pathogenesis of NEC, in which upregulated CCL3 expression exacerbated inflammatory intestinal damage by regulating macrophage chemotaxis and M1 phenotype polarization, suggesting that blocking CCL3 may be a potential strategy for effective intervention in NEC. Our study represents an important conceptual advancement that CCL3 may be one of the key culprits of intestinal tissue damage in patients with NEC. CCL3 aggravates inflammatory intestinal injury and intestinal mucosal barrier imbalance by regulating the chemotaxis, polarization, and function of macrophages. Blocking CCL3 significantly reduced NEC-mediated intestinal injury, suggesting a new potential therapeutic strategy.

Dietary exposure to polystyrene nanoplastics impairs fasting-induced lipolysis in adipose tissue from high-fat diet fed mice

The health concerns of microplastics (MPs) and nanoplastics (NPs) surge, but the key indicators to evaluate the adverse risks of MPs/NPs are elusive. Recently, MPs/Ps were found to disturb glucose and lipid metabolism in rodents, suggesting that MPs/NPs may play a role in obesity progression. In this study, we firstly demonstrated that the distribution of fluorescent polystyrene nanoplastics (nPS, 60 nm) white adipose tissue (WAT) of mice. Furthermore, nPS could traffic across adipocytes in vitro and reduced lipolysis under β-adrenergic stimulation in adipocytes in vitro and ex vivo. Consistently, chronic oral exposure to nPS at the dietary exposure relevant concentrations (3 and 223 μg/kg body weight) impaired fasting-induced lipid mobilization in obese mice and subsequently contributed to larger adipocyte size in the subcutaneous WAT. In addition, the chronic exposure of nPS induced macrophage infiltration in the small intestine and increased lipid accumulation in the liver, accelerating the disruption of systemic metabolism. Collectively, our findings highlight the potential obesogenic role of nPS via diminishing lipid mobilization in WAT of obese mice and suggest that lipolysis relevant parameters may be used for evaluating the adverse effect of MPs/NPs in clinics.

Acinar Cell-Derived Extracellular Vesicle MiRNA-183-5p Aggravates Acute Pancreatitis by Promoting M1 Macrophage Polarization Through Downregulation of FoxO1.

Acute pancreatitis (AP) is a common cause of a clinically acute abdomen. Crosstalk between acinar cells and leukocytes (especially macrophages) plays an important role in the development of AP. However, the mechanism mediating the interaction between acinar cells and macrophages is still unclear. This study was performed to explore the role of acinar cell extracellular vesicles (EVs) in the crosstalk between acinar cells and macrophages involved in the pathogenesis of AP. EVs derived from caerulein-treated acinar cells induced macrophage infiltration and aggravated pancreatitis in an AP rat model. Further research showed that acinar cell-derived EV miR-183-5p led to M1 macrophage polarization by downregulating forkhead box protein O1 (FoxO1), and a dual-luciferase reporter assay confirmed that FoxO1 was directly inhibited by miR-183-5p. In addition, acinar cell-derived EV miR-183-5p reduced macrophage phagocytosis. Acinar cell-derived EV miR-183-5p promoted the pancreatic infiltration of M1 macrophages and increased local and systemic damage in vivo. Subsequently, miR-183-5p overexpression in macrophages induced acinar cell damage and trypsin activation, thus further exacerbating the disease. In clinical samples, elevated miR-183-5p levels were detected in serum EVs and positively correlated with the severity of AP. EV miR-183-5p might play an important role in the development of AP by facilitating M1 macrophage polarization, providing a new insight into the diagnosis and targeted management of pancreatitis.Graphical abstract of the present study. In our caerulein-induced AP model, miR-183-5p was upregulated in injured acinar cells and transported by EVs to macrophages. miR-183-5p could induce M1 macrophage polarization through downregulation of FoxO1 and the release of inflammatory cytokines, which could aggravate AP-related injuries. Therefore, a vicious cycle might exist between injured ACs and M1 macrophage polarization, which is fulfilled by EV-transported miR-183-5p, leading to sustainable and progressive AP-related injuries.

The effect of hyperglycaemia on the macrophages in the cell culture.

The availability of glucose in tissue has a role in macrophages polarisation into an inflammatory phenotype. The overnutrition condition such as hyperglycaemia induces macrophage infiltration especially the inflammatory macrophages. The aim of this study was to analyse the effect of hyperglycaemia condition on cytokines production by human monocytes-derived macrophages. Monocyte cells obtained from peripheral blood mononuclear cells isolation from donors were incubated for 6 days in 37°C, 5% CO2. On day 4, the stimulating factors such as lipopolysaccharide (LPS) and interferon gamma were added to activate monocytes into macrophages. Then, on day 6, two doses of glucose; either normal or high doses along with low or high dose of LPS were given for 24 h, followed by collecting the culture media and cells then stored at -80°C until assayed. There was a significant difference in tumour necrosis factor alpha (TNF-a) levels among groups, with highest level found in group with high-dose glucose plus high-dose LPS. However, the concentration of interleukin-6 (IL-6) among groups was not significantly different. Macrophages treated with high-dose glucose plus high-dose LPS significantly increased production of TNF-a, but not of IL-6.

Injectable sericin based nanocomposite hydrogel for multi-modal imaging-guided immunomodulatory bone regeneration

• An injectable alginate/sericin/graphene oxide (Alg/Ser/GO) hydrogel was fabricated. • The released sericin of Alg/Ser/GO hydrogel promoted macrophage M2 polarization. • Synergistic effects on bone regeneration between sericin and GO were demonstrated. • The injected Alg/Ser/GO hydrogels with BMSCs promptly repaired bone defect in rats. Irregular bone defects, where the inflammation and immune microenvironment confronted with implanted biomaterials, remain a prominent challenge for bone regeneration. In this study, we fabricated an injectable alginate/sericin/graphene oxide (Alg/Ser/GO) hydrogel based on the Alg–Tyramine framework with HRP/H 2 O 2 enzymatic crosslinking. This hydrogel exhibited bioimaging property and controlled degradation behavior upon releasing sericin and GO. Importantly, synergistic effects on bone regeneration between sericin and GO were demonstrated. GO significantly enhanced the spreading, osteogenic differentiation, and mineralization of encapsulated rat BMSCs, whereas the released sericin promoted M2 polarization and migration via the NF-κB and MAPK pathways. The M2 polarization of macrophages induced osteogenic differentiation of BMSCs via several secreted cytokines. Both in vivo and in vitro experiments showed that the Alg/Ser/GO hydrogel induced macrophage infiltration into the surrounding tissues and inhibited inflammation and fibrous capsule thickening. Last, the injected Alg/Ser/GO hydrogels with BMSCs promptly repaired established distal femoral defects in rats. Therefore, the fabricated Alg/Ser/GO hydrogel, along with macrophages and BMSCs, is a promising biomaterial for bone healing, especially the irregular bone defects.

Preclinical Verification of the Efficacy and Safety of Aqueous Plasma for Ovarian Cancer Therapy.

Simple SummaryOvarian cancer is among the most malignant gynecologic cancers, in part because intraperitoneal recurrence occurs with high frequency due to occult metastasis. We have demonstrated a metastasis-inhibitory effect of plasma-activated medium (PAM) in ovarian cancer cells. Here, we investigated whether PAM inhibits intraperitoneal metastasis. We observed that PAM induced macrophages’ infiltration into the disseminated lesion, which was co-localized with inducible nitric oxide synthase (iNOS)-positive signal, indicating that PAM might induce M1-type macrophages. We also observed that intraperitoneal washing with plasma-activated lactate Ringer’s solution (PAL) significantly improved the overall survival rate in an ovarian cancer mouse model. Intraperitoneal washing therapy might be effective to improve clinical outcomes of ovarian cancer.Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. The major cause of EOC’s lethality is that intraperitoneal recurrence occurs with high frequency due to occult metastasis. We had demonstrated that plasma-activated medium (PAM) exerts a metastasis-inhibitory effect on ovarian cancer in vitro and in vivo. Here we investigated how PAM inhibits intraperitoneal metastasis. We studied PAM’s inhibition of micro-dissemination onto the omentum by performing in vivo imaging in combination with a sequential histological analysis. The results revealed that PAM induced macrophage infiltration into the disseminated lesion. The iNOS-positive signal was co-localized at the macrophages in the existing lesion, indicating that PAM might induce M1-type macrophages. This may be another mechanism of the antitumor effect through a PAM-evoked immune response. Intraperitoneal lavage with plasma-activated lactate Ringer’s solution (PAL) significantly improved the overall survival rate in an ovarian cancer mouse model. Our results demonstrated the efficiency and practicality of aqueous plasma for clinical applications.

Study on the state of macrophage infiltration in the progression of non-alcoholic fatty liver disease induced by high-fat diet in mice

Objective: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. Macrophages are an important cell-mediated immune response in the pathogenesis of NAFLD. However, the dynamic changes of intrahepatic infiltration during the pathogenesis of NAFLD remains unclear. Therefore, this study intends to investigate the changes and their correlations with morphological indicators, hepatic histopathological index, and intrahepatic macrophage infiltration in the progression of NAFLD induced by high-fat diet in mice. Methods: C57BL/6J mice were fed with 42% high-fat diet, and the morphological data and liver tissue were obtained at 1, 2, 4, 8 and 12 months, respectively. Hepatic histopathological characteristics were evaluated by HE stain. Immunohistochemical staining was used to detect the number of F4/80 positive cells in liver tissue at different stages to evaluate the degree of intrahepatic macrophage infiltration. Results: (1) The body weight, liver weight, and liver weight/body weight of mice fed with high-fat diet had gradually increased. (2) HE staining results showed that mice fed with high-fat diet had mainly developed simple steatosis within 1 to 2 months. In addition, a balloon-like hepatocyte degeneration and intralobular inflammation had begun to appear at 4 months, indicating that non-alcoholic steatohepatitis had started, and can be seen very clearly at 8 to 12 months. (3) Immunohistochemical staining results suggested that in the simple steatosis stage of NAFLD, the intrahepatic macrophage infiltration was not significant. However, after NAFLD activity score > 3, a large amount of infiltration had appeared and cluster-like changes in the later stage. (4) Correlation analysis results indicated that the degree of macrophage infiltration was not related to the mice morphological indicators (body weight, liver weight and liver weight/body weight) and pathological indicators (percentage of hepatic steatotic change, and degree of hepatocyte ballooning and intralobular inflammation), but was significantly related to the NAFLD activity score. Conclusion: High-fat diet can successfully induce NAFLD in mice and progress to the stage of non-alcoholic steatohepatitis. At the same time, high-fat diet can induce macrophage infiltration in liver tissue of mice and the changing trend of infiltration is related to NAFLD activity score.

INTERLEUKIN-6 PLAYS CRITICAL ROLE ON ALDOSTERONE INDUCED MACROPHAGE INFILTRATION IN MYOCARDIUM

Objective: An excess of aldosterone results in cardiac remodelling and fibrosis. The key step of aldosterone-induced cardiac fibrosis is macrophage infiltration. In our previous studies, Interleukin-6 (IL-6) is a key mediator in the aldosterone-induced fibrotic process, however the effect of aldosterone on macrophage remains unclear. We investigated whether aldosterone induces the expression of IL-6 and thereby contributes to the macrophage infiltration in myocardium.Design and method: In cell studies, we investigated the possible molecular mechanism how aldosterone induced IL-6 secretion in macrophage and the further effects of macrophage migration and infiltration. Results: Aldosterone significantly induced IL-6 production in THP-1 cells. Intracellular signalling occurred through the mineralocorticoid receptor->PI3K/Akt/p38->NF-kB/NFIL-6 pathway. In macrophage migration and infiltration (RAW 264.7 cells), IL-6 blockage abolished the effect of aldosterone-induced macrophage migration and infiltration. In addition, aldosterone induced macrophage to produce MMP-1 and mmp-9 which through IL-6->JAK/Cox-2->PGE2->EP2/EP4 pathway. To further investigate the role of IL-6 signalling in aldosterone-induced macrophage infiltration, we measured the severity of macrophage infiltration in myocardium in aldosterone infusion mice models including an IL-6 chemical inhibitor and Sgp130 Knockin Transgenic Mice. Mice receiving IL-6 antibody and Sgp130 Knockin Transgenic Mice prevented increased macrophage infiltration in myocardium by aldosterone infusion. Conclusions: IL-6 plays critical role on aldosterone induced macrophage infiltration in myocardium

Inhibitory Effects of Sodium Alginate on Hepatic Steatosis in Mice Induced by a Methionine- and Choline-deficient Diet.

Nonalcoholic steatohepatitis (NASH) progresses from nonalcoholic fatty liver disease (NAFLD); however, efficacious drugs for NASH treatment are lacking. Sodium alginate (SA), a soluble dietary fiber extracted from brown algae, could protect the small intestine from enterobacterial invasion. NASH pathogenesis has been suggested to be associated with enterobacterial invasion, so we examined the effect of SA on methionine- and choline-deficient (MCD) diet-induced steatohepatitis in mice (the most widely-used model of NASH). The mice (n = 31) were divided into three groups (mice fed with regular chow, MCD diet, and MCD diet premixed with 5% SA) for 4 and 8 weeks. The MCD diet increased lipid accumulation and inflammation in the liver, the NAFLD Activity Score and hepatic mRNA expression of tumor necrosis factor-α and collagen 1α1, and induced macrophage infiltration. Villus shortening, disruption of zonula occludens-1 localization and depletion of mucus production were observed in the small intestine of the MCD-group mice. SA administration improved lipid accumulation and inflammation in the liver, and impaired barrier function in the small intestine. Collectively, these results suggest that SA is useful for NASH treatment because it can prevent hepatic inflammation and fatty degeneration by maintaining intestinal barrier function.

The association between local arteriosclerosis of the prostatic arteries and chronic inflammation in human benign prostatic enlargement.

To elucidate the pathogenesis of benign prostatic enlargement (BPE) in humans due to chronic inflammation caused by arteriosclerosis, the relationships between prostate size and the degree of chronic inflammation induced by local arteriosclerosis were investigated. The present cohort included 50 subjects who underwent robot-assisted radical prostatectomy (RARP) in a prospective study. The presence or absence of local arteriosclerosis in the prostatic arteries removed during RARP was evaluated by microscopic assessment. Chronic inflammation in the prostate was judged according to both the density and the extent of inflammatory cells. The expression of lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and the infiltration of macrophages in the prostate, which are high in arteriosclerosis, were investigated by immunohistochemistry. Local arteriosclerosis was observed in 28% (14/50). Prostate size and the inflammation score were significantly increased in the presence of arteriosclerosis (P = 0.006, P < 0.001, respectively). There was also a significant increase of LOX-1 in the epithelial and stromal cells of the prostate in the presence of arteriosclerosis (all, P < 0.001). Concerning the presence of macrophages, subjects with arteriosclerosis had significantly more positive expression of ionized calcium-binding adapter molecule-1 (IBA-1), a marker of macrophages, than subjects without arteriosclerosis (P < 0.001). In human surgical specimens, chronic inflammation owing to local arteriosclerosis of the prostatic arteries was significantly related to prostatic enlargement. Given the immunohistochemical analyses, the putative pathogenesis for this relationship is that LOX-1 induces macrophage infiltration, leading to BPE.

EGFR Cooperates with EGFRvIII to Recruit Macrophages in Glioblastoma.

: Amplification of the EGFR gene and its truncation mutant EGFRvIII are hallmarks of glioblastoma. Although coexpression of EGFR and EGFRvIII confers a growth advantage, how EGFR and EGFRvIII influence the tumor microenvironment remains incompletely understood. Here, we show that EGFR and EGFRvIII cooperate to induce macrophage infiltration via upregulation of the chemokine CCL2. EGFRvIII was significantly enriched in glioblastoma patient samples with high CCL2, and knockout of CCL2 in tumors coexpressing EGFR and EGFRvIII led to decreased infiltration of macrophages. KRAS was a critical signaling intermediate for EGFR- and EGFRvIII-induced expression of CCL2. Our results illustrate how EGFR and EGFRvIII direct the microenvironment in glioblastoma. SIGNIFICANCE: Full-length EGFR and truncated EGFRvIII work through KRAS to upregulate the chemokine CCL2 and drive macrophage infiltration in glioblastoma.

Inhibition of stromal cell-derived factor-1α/CXCR4 signaling restores the blood-retina barrier in pericyte-deficient mouse retinas.

In diabetic retinopathy (DR), pericyte dropout from capillary walls is believed to cause the breakdown of the blood-retina barrier (BRB), which subsequently leads to vision-threatening retinal edema. While various proinflammatory cytokines and chemokines are upregulated in eyes with DR, their distinct contributions to disease progression remain elusive. Here, we evaluated roles of stromal cell-derived factor-1α (SDF-1α) and its receptor CXCR4 in the BRB breakdown initiated by pericyte deficiency. After inhibition of pericyte recruitment to developing retinal vessels in neonatal mice, endothelial cells (ECs) upregulated the expression of SDF-1α. Administration of CXCR4 antagonists, or EC-specific disruption of the CXCR4 gene, similarly restored the BRB integrity, even in the absence of pericyte coverage. Furthermore, CXCR4 inhibition significantly decreased both the expression levels of proinflammatory genes (P < 0.05) and the infiltration of macrophages (P < 0.05) into pericyte-deficient retinas. Taken together, EC-derived SDF-1α induced by pericyte deficiency exacerbated inflammation through CXCR4 in an autocrine or paracrine manner and thereby induced macrophage infiltration and BRB breakdown. These findings suggest that the SDF-1α/CXCR4 signaling pathway may be a potential therapeutic target in DR.

Macrophages mediate corticotomy-accelerated orthodontic tooth movement

Clinical evidence has suggested that surgical corticotomy of the alveolar bone can accelerate local orthodontic tooth movement (OTM), but the underlying cell and molecular mechanisms remain largely unclear. The present study examined the role of macrophages played in corticotomy-assisted OTM. Orthodontic nickel-titanium springs were applied to the left maxillary first molars of rats or mice to induce OTM with or without corticotomy. Corticotomy enhanced OTM distance by accelerating movement through induction of local osteoclastogenesis and macrophage infiltration during OTM. Further analysis showed that macrophages were polarized toward an M1-like phenotype immediately after corticotomy and then switched to an M2-like phenotype during OTM. The microenvironment of corticotomy induced macrophage infiltration and polarization through the production of TNF-α. More importantly, the amount of OTM induced by corticotomy was significantly decreased after mice were depleted of monocyte/macrophages by injection of liposome-encapsulated clodronate. Further experiments by incubating cultured macrophages with fresh tissue suspension obtained from post-corticotomy gingiva switched the cells to an M1 phenotype through activation of the nuclear factor-κB (NF-κB) signaling pathway, and to an M2 phenotype through activation of the JAK/STAT3 signaling pathway. Our results suggest that corticotomy induces macrophage polarization first by activating the NF-κB signaling pathway and later by activating the JAK/STAT3 signaling pathway, and that these processes contribute to OTM by triggering production of inflammatory cytokines and osteoclastogenesis.

Pirfenidone inhibits cryoablation induced local macrophage infiltration along with its associated TGFb1 expression and serum cytokine level in a mouse model

PurposeTo investigate the effects of pirfenidone (PFD) on post-cryoablation inflammation in a mouse model. Materials and methodsIn this IACUC-approved study, eighty Balb/c mice were randomly divided into four groups (20/group): sham + vehicle, sham + PFD, cryoablation + vehicle, and cryoablation + PFD. For cryoablation groups, a 20% freeze rate cryoablation (20 s to less than −100 °C) was used to ablate normal muscle in the right flank. For sham groups, the cryoprobe was advanced into the flank and maintained for 20 s without ablation. PFD or vehicle solution was intraperitoneally injected (5 mg/kg) at days 0, 1, 2, 3, and then every other day until day 13 after cryoablation. Mice were euthanized at days 1, 3, 7, and 14. Blood samples were used for serum IL-6, IL-10, and TGFβ1 analysis using electrochemiluminescence and ELISA assays, respectively. Immunohistochemistry-stained ablated tissues were used to analyze macrophage infiltration and local TGFβ1 expression in the border region surrounding the cryoablation-induced coagulation zone. ResultsCryoablation induced macrophage infiltration and increased TGFβ1 expression in the border of the necrotic zone, and high levels of serum IL-6, peaking at days 7 (70.5 ± 8.46/HPF), 14 (228 ± 18.36/HPF), and 7 (298.67 ± 92.63), respectively. Animals receiving PFD showed reduced macrophage infiltration (35.5 ± 16.93/HPF at day 7, p < 0.01) and cytokine levels (60.2 ± 7.6/HPF at day 14, p < 0.01). PFD also significantly reduced serum IL-6 levels (p < 0.001 vs. all non-PFD groups). ConclusionsPFD mitigates cryoablation induced muscle tissue macrophage infiltration, increased IL-6 levels, and local TGFβ1 expression in a small animal model.