Enhanced Macrophage Recruitment Research Articles

Possible Role of Netrin-1/Deleted in Colorectal Cancer/Vascular Endothelial Growth Factor Signaling Pathway in the Pathogenesis of Placenta Accreta Spectrum: A Case-control Study.

Netrin-1, an epithelial-secreted protein, plays a key role in placental formation through the promotion of cytotrophoblast proliferation and placental vascular development. These effects are mediated through several receptors, including the deleted in colorectal cancer (DCC) receptor. Placenta accreta spectrum (PAS) is an exaggerated trophoblastic invasion into the uterine myometrium. The exact etiology is unknown, but it is believed that increased trophoblastic invasion, defect decidualization, and/or abnormal angiogenesis might play a role. Our study aimed to investigate the suggested role of macrophage-induced netrin-1/DCC/vascular endothelial growth factor (VEGF) signaling in PAS pathogenesis. A total of 29 women with PAS (as cases) and 29 women with normal pregnancies (as controls) were enrolled in the study. At delivery, placental tissues of both groups were collected and processed for the evaluation of placental netrin-1 level by enzyme-linked immunoassay technique and immunohistochemical analysis of tissue DCC receptor. Placental tissue netrin-1 level of PAS cases showed a statistically significantly higher value than those in the normal group. Significant overexpression of DCC receptors, VEGF, and enhanced macrophage recruitment was noted in PAS cases in comparison to the normal placenta. Macrophage-induced netrin-1/DCC/VEGF signaling might be involved in PAS pathogenesis through the enhancement of trophoblastic angiogenesis.

FNIP1 abrogation promotes functional revascularization of ischemic skeletal muscle by driving macrophage recruitment

Ischaemia of the heart and limbs attributable to compromised blood supply is a major cause of mortality and morbidity. The mechanisms of functional angiogenesis remain poorly understood, however. Here we show that FNIP1 plays a critical role in controlling skeletal muscle functional angiogenesis, a process pivotal for muscle revascularization during ischemia. Muscle FNIP1 expression is down-regulated by exercise. Genetic overexpression of FNIP1 in myofiber causes limited angiogenesis in mice, whereas its myofiber-specific ablation markedly promotes the formation of functional blood vessels. Interestingly, the increased muscle angiogenesis is independent of AMPK but due to enhanced macrophage recruitment in FNIP1-depleted muscles. Mechanistically, myofiber FNIP1 deficiency induces PGC-1α to activate chemokine gene transcription, thereby driving macrophage recruitment and muscle angiogenesis program. Furthermore, in a mouse hindlimb ischemia model of peripheral artery disease, the loss of myofiber FNIP1 significantly improved the recovery of blood flow. Thus, these results reveal a pivotal role of FNIP1 as a negative regulator of functional angiogenesis in muscle, offering insight into potential therapeutic strategies for ischemic diseases.

CXCL17 Attenuates Diesel Exhaust Emissions Exposure-Induced Lung Damage by Regulating Macrophage Function.

Exposure to diesel exhaust emissions (DEE) is strongly linked to innate immune injury and lung injury, but the role of macrophage chemoattractant CXCL17 in the lung damage caused by DEE exposure remains unclear. In this study, whole-body plethysmography (WBP), inflammatory cell differential count, and histopathological analysis were performed to assess respiratory parameters, airway inflammation, and airway injury in C57BL/6 male mice exposed to DEE for 3 months. qRT-PCR, IHC (immunohistochemistry), and ELISA were performed to measure the CXCL17 expression in airway epithelium or BALF (bronchoalveolar lavage fluid) following DEE/Diesel exhaust particle (DEP) exposure. Respiratory parameters, airway inflammation, and airway injury were assessed in CXCL17-overexpressing mice through adeno-associated virus vector Type 5 (AAV5) infection. Additionally, an in vitro THP-1 and HBE co-culture system was constructed. Transwell assay was carried out to evaluate the effect of rh-CXCL17 (recombinant human protein-CXCL17) on THP-1 cell migration. Flow cytometry and qRT-PCR were conducted to assess the impacts of rh-CXCL17 on apoptosis and inflammation/remodeling of HBE cells. We found that the mice exposed to DEE showed abnormal respiratory parameters, accompanied by airway injury and remodeling (ciliary injury in airway epithelium, airway smooth muscle hyperplasia, and increased collagen deposition). Carbon content in airway macrophages (CCAM), but not the number of macrophages in BALF, increased significantly. CXCL17 expression significantly decreased in mice airways and HBE after DEE/DEP exposure. AAV5-CXCL17 enhanced macrophage recruitment and clearance of DEE in the lungs of mice, and it improved respiratory parameters, airway injury, and airway remodeling. In the THP-1/HBE co-culture system, rh-CXCL17 increased THP-1 cell migration while attenuating HBE cell apoptosis and inflammation/remodeling. Therefore, CXCL17 might attenuate DEE-induced lung damage by recruiting and activating pulmonary macrophages, which is expected to be a novel therapeutic target for DEE-associated lung diseases.

Cyclodextrin-mediated conjugation of macrophage and liposomes for treatment of atherosclerosis.

Current pharmacological treatments of atherosclerosis often target either cholesterol control or inflammation management, to inhibit atherosclerotic progression, but cannot lead to direct plaque lysis and atherosclerotic regression, partly due to the poor accumulation of medicine in the atherosclerotic plaques. Due to enhanced macrophage recruitment during atheromatous plaque progression, a macrophage-liposome conjugate was facilely constructed for targeted anti-atherosclerosis therapy via synergistic plaque lysis and inflammation alleviation. Endogenous macrophage is utilized as drug-transporting cell, upon membrane-modification with a β-cyclodextrin (β-CD) derivative to form β-CD decorated macrophage (CD-MP). Adamantane (ADA) modified quercetin (QT)-loaded liposome (QT-NP), can be conjugated to CD-MP via host-guest interactions between β-CD and ADA to form macrophage-liposome conjugate (MP-QT-NP). Thus, macrophage carries liposome "hand-in-hand" to significantly increase the accumulation of anchored QT-NP in the aorta plaque in response to the plaque inflammation. In addition to anti-inflammation effects of QT, MP-QT-NP efficiently regresses atherosclerotic plaques from both murine aorta and human carotid arteries via CD-MP mediated cholesterol efflux, due to the binding of cholesterol by excess membrane β-CD. Transcriptome analysis of atherosclerotic murine aorta and human carotid tissues reveal that MP-QT-NP may activate NRF2 pathway to inhibit plaque inflammation, and simultaneously upregulate liver X receptor to promote cholesterol efflux.

Matrix metalloproteinase-21 promotes metastasis via increasing the recruitment and M2 polarization of macrophages in HCC.

MMP-21 is a newly identified member of the matrix metalloproteinase family and has been reported to regulate both embryonic development and tumor progression. However, the roles of MMP-21 in hemofiltrate C-C chemokine (HCC) remain largely unclear. In this study, we used western blot, qPCR and immunohistochemistry (IHC) to determine the upregulation of MMP-21 in HCC tissues, and showed that the increase in MMP-21 was associated with vascular invasion and poor prognosis. Although changing levels of MMP-21 in HCC cell lines had no significant effect on cell migration or invasion abilities in in vitro transwell tests, both IHC analysis and in vivo mouse models proved that upregulated MMP-21 promoted metastasis. Functional enrichments of MMP-21 using The Cancer Genome Atlas (TCGA) data suggested that MMP-21might regulate metastasis via macrophages. Further experiments proved that MMP-21 enhanced macrophage recruitment by increasing CCL-14levels and promoted M2-type polarization of macrophage by elevating the expression of CSF-1 and FGF-1. Taken together, this study revealed that MMP-21 controlled the tumor microenvironment remodeling and functional regulation of macrophages to regulate HCC metastasis.

Autophagy and Exosome Coordinately Enhance Macrophage M1 Polarization and Recruitment in Influenza A Virus Infection.

BackgroundInfluenza A virus infection results in viral pneumonia, which is often accompanied by the infiltration and recruitment of macrophages, overactivation of inflammatory responses, and obvious cell autophagy and exosome production. However, little is known about the roles of autophagy and exosome production in these inflammatory responses.MethodsIn this study, multiple methods, such as flow cytometry, real-time quantitative reverse transcription-polymerase chain reaction, immune–fluorescence technology, and western blot, were applied to explore the possible effects of autophagy and exosome production by H1N1-infected host cells.ResultsIt was observed that a high number of polarized macrophages (CD11b+/F4/80+/CD86+) were recruited to the lung tissues of infected mice, which could be mimicked by tracking the movement of macrophages to H1N1-infected cells in vitro (transwell assays). Furthermore, there was some coordinated upregulation of M1 polarization signs (iNOS/Arg-1 bias) as well as autophagy (LC3) and exosome (CD63) biomarkers in the infected macrophages and epithelial cells. Moreover, exosomes extracted from the supernatant of virus-infected cells were shown to promote the recruitment and polarization of more peritoneal macrophages than the normal group. The fluorescence colocalization of LC3-CD63 and the inhibition of autophagy and exosome signaling pathway further revealed that H1N1 infection seemed to sequentially activate the M1 polarization and recruitment of macrophages via autophagy–exosome dependent pathway.ConclusionAutophagy and exosome production coordinately enhance the M1 polarization and recruitment of macrophages in influenza virus infection, which also provides potential therapeutic targets.

Long Noncoding RNA SLC20A1-1 Induces Nucleus Pulposus Apoptosis by Sponging miR-146a-5p

Background: Intervertebral disc degeneration (IDD) is a common cause of lower back pain and is characterized by cellular apoptosis, senescence, and extracellular matrix degradation. In the current study, we aimed to identify the effect of the long noncoding RNA SLC20A1-1 on tumor necrosis factor α (TNF-α)-induced apoptosis of nuclear pulposus cells (NPCs). Materials and Methods: NPCs were induced by TNF-α and used as an in vitro model. The mRNA expression of SLC20A1-1 was detected by quantitative real-time PCR (qPCR) both in clinical samples and in vitro. The scratch assay, Transwell invasion assay, CCK-8 assay, and flow cytometry were used to measure cell migration, growth, and apoptosis. The binding site between SLC20A1-1 and miR-146a-5p was assessed by a dual-luciferase reporter assay. Results: The expression of SLC20A1-1 was significantly upregulated in herniated lumbar discs, and TNF-α induced SLC20A1-1 expression in NPCs. Overexpression of SLC20A1-1 inhibited NPC growth, promoted NPC apoptosis, and enhanced macrophage recruitment and migration. The effect of SLC20A1-1 on NPCs and macrophages could be reversed by etanercept treatment. Moreover, we found that SLC20A1-1 could suppress miR-146a-5p to induce TRAF6 and caspase 3 expression. Conclusion: Overall, SLC20A1-1, an IDD regulator, is involved in TNF-α-induced NPC apoptosis by sponging miR-146a-5p. Clinical Trial Registration number: NMU20210325.

The Effect of Fluence on Neutrophil Kinetics in Zebrafish Wounds Using Real-time In Vivo Imaging

Background: Neutrophils participate in a cooperative defense strategy with macrophages following tissue injury. Application of low dose electromagnetic radiation via 635 nm wavelength can enhance macrophage recruitment to the wound, decrease tissue levels of ROS and speed healing. The impact of this wavelength on neutrophil activity in vivo is not well-described. Given that wound healing can be enhanced if collateral damage by neutrophils within the wound is decreased, we investigated how neutrophil kinetics changed during these accelerated reparative responses. Methods: Zebrafish, transgenic for the fluorescent neutrophil marker, mpx-dendra2, underwent defined fin tissue injury, and were randomized to one of two laser treatment groups, 3 J/cm2 (n=57), or 18 J/cm2 (n=69) or to the control group, 0 J/cm2 (n=164). Electromagnetic wave exposures were administered by a 635-nm continuous 5mW He:Ne laser with recipients randomized by dose delivered. Fish were three-dimensionally time-lapse imaged 30-120 minutes post injury (mpi) and wound healing documented at 24 hours post-injury. Individual neutrophil movement was tracked according to distance from wound center. Results: The lower treatment fluence, 3 J/cm2, significantly decreased neutrophil migration speed into the wound, increased reverse migration, and promoted stasis outside the adjacent wound area when compared to control and higher energy doses. The 3 J/cm2 treatment groups also exhibited more rapid wound closure when compared to control or higher fluence. Conclusions: Unlike our previous work in macrophages in which low fluence treatment enhanced the speed of forward directed migration into the wound, the response of neutrophils was decreased speed into the wound, increased reverse migration, and stasis outside the areas of the wound edges. These findings advance the notion that low fluence treatments reduce neutrophil inflammatory responses within the wound by their reduced presence within the wound. Reduced neutrophil-mediated collateral damage may work in concert with enhanced macrophage wound activity to promote faster wound healing.

Treatment of glioblastoma with current oHSV variants reveals differences in efficacy and immune cell recruitment

Oncolytic herpes simplex viruses (oHSVs) have demonstrated efficient lytic replication in human glioblastoma tumors using immunodeficient mouse models, but early-phase clinical trials have reported few complete responses. Potential reasons for the lack of efficacy are limited vector potency and the suppressive glioma tumor microenvironment (TME). Here we compare the oncolytic activity of two HSV-1 vectors, a KOS-strain derivative KG4:T124 and an F-strain derivative rQNestin34.5v.1, in the CT2A and GL261N4 murine syngeneic glioma models. rQNestin34.5v1 generally demonstrated a greater in vivo viral burden compared to KG4:T124. However, both vectors were rapidly cleared from CT2A tumors, while virus remained ensconced in GL261N4 tumors. Immunological evaluation revealed that the two vectors induced similar changes in immune cell recruitment to either tumor type at 2 days after infection. However, at 7 days after infection, the CT2A microenvironment displayed the phenotype of an untreated tumor, while GL261N4 tumors exhibited macrophage and CD4+/CD8+ T cell accumulation. Furthermore, the CT2A model was completely resistant to virus therapy, while in the GL261N4 model rQNestin34.5v1 treatment resulted in enhanced macrophage recruitment, impaired tumor progression, and long-term survival of a few animals. We conclude that prolonged intratumoral viral presence correlates with immune cell recruitment, and both are needed to enhance anti-tumor immunity.

Ascorbic acid accelerates Wallerian degeneration after peripheral nerve injury

Wallerian degeneration occurs after peripheral nerve injury and provides a beneficial microenvironment for nerve regeneration. Our previous study demonstrated that ascorbic acid promotes peripheral nerve regeneration, possibly through promoting Schwann cell proliferation and phagocytosis and enhancing macrophage proliferation, migration, and phagocytosis. Because Schwann cells and macrophages are the main cells involved in Wallerian degeneration, we speculated that ascorbic acid may accelerate this degenerative process. To test this hypothesis, 400 mg/kg ascorbic acid was administered intragastrically immediately after sciatic nerve transection, and 200 mg/kg ascorbic acid was then administered intragastrically every day. In addition, rat sciatic nerve explants were treated with 200 μM ascorbic acid. Ascorbic acid significantly accelerated the degradation of myelin basic protein-positive myelin and neurofilament 200-positive axons in both the transected nerves and nerve explants. Furthermore, ascorbic acid inhibited myelin-associated glycoprotein expression, increased c-Jun expression in Schwann cells, and increased both the number of macrophages and the amount of myelin fragments in the macrophages. These findings suggest that ascorbic acid accelerates Wallerian degeneration by accelerating the degeneration of axons and myelin in the injured nerve, promoting the dedifferentiation of Schwann cells, and enhancing macrophage recruitment and phagocytosis. The study was approved by the Southern Medical University Animal Care and Use Committee (approval No. SMU-L2015081) on October 15, 2015.

MiR-1207-5p Can Contribute to Dysregulation of Inflammatory Response in COVID-19 via Targeting SARS-CoV-2 RNA.

The present study focuses on the role of human miRNAs in SARS-CoV-2 infection. An extensive analysis of human miRNA binding sites on the viral genome led to the identification of miR-1207-5p as potential regulator of the viral Spike protein. It is known that exogenous RNA can compete for miRNA targets of endogenous mRNAs leading to their overexpression. Our results suggest that SARS-CoV-2 virus can act as an exogenous competing RNA, facilitating the over-expression of its endogenous targets. Transcriptomic analysis of human alveolar and bronchial epithelial cells confirmed that the CSF1 gene, a known target of miR-1207-5p, is over-expressed following SARS-CoV-2 infection. CSF1 enhances macrophage recruitment and activation and its overexpression may contribute to the acute inflammatory response observed in severe COVID-19. In summary, our results indicate that dysregulation of miR-1207-5p-target genes during SARS-CoV-2 infection may contribute to uncontrolled inflammation in most severe COVID-19 cases.

Macrophage-specific deletion of BACE1 does not enhance macrophage recruitment to the injured peripheral nerve

Following peripheral nerve injury, macrophages are recruited to the injury site from circulation to clear cellular debris. Injured β-secretase 1 (BACE1) knockout mice have enhanced macrophage recruitment and debris clearance, which may be due to BACE1 activity in macrophages or the hypomyelination observed in BACE1 knockout mice. To assess if BACE1 expression by macrophages mediates enhanced macrophage recruitment we utilized mice with macrophage specific deletion of BACE1 and saw no increase in macrophage recruitment following injury. This study suggests that expression of BACE1 by macrophages may not be essential for increased recruitment observed previously in global BACE1 KO mice.

Self-assembling multidomain peptide hydrogels accelerate peripheral nerve regeneration after crush injury

Multidomain peptide (MDP) hydrogels are a class of self-assembling materials that have been shown to elicit beneficial responses for soft tissue regeneration. However, their capacity to promote nervous system regeneration remains unknown. The peripheral nervous system (PNS) substantially recovers after injury, partly due to the abundance of extracellular matrix (ECM) components in its basal lamina. However, severe peripheral nerve injuries that significantly damage the ECM continue to be a major clinical challenge as they occur at a high rate and can be extremely detrimental to patients’ quality of life. In this study, a panel of eight MDPs were designed to contain various motifs mimicking extracellular matrix components and growth factors and successfully self-assembled into injectable, nanofibrous hydrogels. Using an in vitro screening system, various lysine based MDPs were found to enhance neurite outgrowth. To test their capacity to promote nerve regeneration in vivo, rat sciatic nerve crush injury was performed with MDP hydrogels injected directly into the injury sites. MDP hydrogels were found to enhance macrophage recruitment to the injury site and degrade efficiently over time. Rats that were injected with the MDP hydrogel K2 and laminin motif-containing MDPs K2-IIKDI and K2-IKVAV were found to have significantly accelerated functional recovery and remyelination compared to those injected with HBSS or other MDPs. These results demonstrate that MDPs enhance neurite outgrowth and promote a multicellular pro-regenerative response in peripheral nerve injury. This study provides important insights into the potential of MDPs as biomaterials for nerve regeneration and other clinical applications.

A High Docosahexaenoic Acid Diet Alters the Lung Inflammatory Response to Acute Dust Exposure.

Agricultural workers are at risk for the development of acute and chronic lung diseases due to their exposure to organic agricultural dusts. A diet intervention using the omega-3 fatty acid docosahexaenoic acid (DHA) has been shown to be an effective therapeutic approach for alleviating a dust-induced inflammatory response. We thus hypothesized a high-DHA diet would alter the dust-induced inflammatory response through the increased production of specialized pro-resolving mediators (SPMs). Mice were pre-treated with a DHA-rich diet 4 weeks before being intranasally challenged with a single dose of an extract made from dust collected from a concentrated swine feeding operation (HDE). This omega-3-fatty-acid-rich diet led to reduced arachidonic acid levels in the blood, enhanced macrophage recruitment, and increased the production of the DHA-derived SPM Resolvin D1 (RvD1) in the lung following HDE exposure. An assessment of transcript-level changes in the immune response demonstrated significant differences in immune pathway activation and alterations of numerous macrophage-associated genes among HDE-challenged mice fed a high DHA diet. Our data indicate that consuming a DHA-rich diet leads to the enhanced production of SPMs during an acute inflammatory challenge to dust, supporting a role for dietary DHA supplementation as a potential therapeutic strategy for reducing dust-induced lung inflammation.

Fe3O4@TiO2-Laden Neutrophils Activate Innate Immunity via Photosensitive Reactive Oxygen Species Release.

Although a variety of advanced sterilization materials and treatments have emerged, the complete elimination of bacterial infection, especially drug-resistant bacterial infection, remains an immense challenge. Here, we demonstrate the use of neutrophils loaded with photocatalytic nanoparticles to reduce bacterial infection. This method activates the immune system to achieve an anti-infection response. We prepared the photocatalytic nanoparticle-laden neutrophils in vivo through neutrophil phagocytosis. The resulting loaded cells retained the cell membrane functionality of the source cell, as well as the complete immune cell function of neutrophils, particularly the ability to recruit macrophages to the target area. Photocatalytic nanoparticle-laden neutrophils can target infection sites and release reactive oxygen species to induce the secretion of chemokines, leading to the targeted recruitment of macrophages and enhancing a powerful immune cascade. In a severe mouse infection model induced by pathogenic bacteria, small doses of photocatalytic nanoparticle-laden neutrophils showed a remarkable therapeutic effect by enhancing macrophage recruitment and the immune cascade.

CTHRC1 promotes M2-like macrophage recruitment and myometrial invasion in endometrial carcinoma by integrin-Akt signaling pathway.

The infiltration of tumor-associated macrophages (TAMs) is associated with tumor progression and poor prognosis in endometrial cancer (EC). Collagen triple helix repeat containing 1 (CTHRC1), a secreted ECM protein, has been reported to have important roles in promoting cancer invasion and metastasis, but the functional role of CTHRC1 and its association with TAMs in EC remain unclear. Here we report that, in EC patients, CTHRC1 expression was up-regulated in endometrial cancer tissues compared with normal endometrium (P < 0.0001), and is positively correlated with tumor grade and depth of myometrial invasion (P = 0.024 and P = 0.0002, respectively). Meanwhile, CTHRC1 expression was positively correlated with an increased number of infiltrating TAMs, especially M2-like TAMs (P = 0.003, P = 0.001). In the tumor microenvironment of EC, CTHRC1 not only promoted myometrial invasion by interacting with Integrin β3-Akt signaling pathway, but also promoted infiltration of M2-like TAMs by upregulating Fractalkine chemokine receptor (CX3CR1) expression in macrophages. Changing levels of recombinant CTHRC1 protein (rCTHRC1) promoted tumor migration and invasion via enhancing macrophage recruitment in vitro. In summary, our findings eventually provided a novel role for CTHRC1 in remodeling the tumor immune microenvironment to promote tumor metastasis in EC patients.

Correction: A functional variant of SMAD4 enhances macrophage recruitment and inflammatory response via TGF-β signal activation in Thoracic aortic aneurysm and dissection.

Thoracic aortic aneurysm and dissection (TAAD) is the most fatal macro vascular disease. The mortality of 48h after diagnosis of dissection is up to approximately 50-68%. However, the genetic factors and potential mechanism underlying sporadic TAAD remain largely unknown. Our previous study suggested rs12455792 variant of SMAD4 gene significantly contributed to the increased risk and might participated the pathological progression of TAAD. This investigation aims to test (1) the associations between rs12455792 and MO recruitment, inflammatory response in aggressiveness of TAAD, and (2) the molecular mechanism accounting for their effects. In TGF-β signaling molecular detection, rs12455792 C>T variant activated the canonical and non-canonical TGF-β mediators. It also increased the secretion of chemotactic factors of HASMCs. To confirm the impact of this change, we detected MO recruitment and infiltration in HASMCs and aortic tissues of TAAD patients. We found that MO recruitment in cells and tissues with rs12455792 variant genotypes was increased than that in wild type groups. Moreover, rs12455792 variant increased M1 type inflammatory response, which might contribute much to TAAD progression. To mimic the SMAD4 suppression effect of rs12455792 in vivo, we constructed the SMAD4 KD mouse. After induction with Ang II for 4w, the thoracic aorta dilatation and vascular remodeling were more serious than that of wild type group. In conclusion, rs12455792 increased MO recruitment, M1 type inflammatory response via activated TGF-β signaling, and further promoted vascular remodeling and pathological progress of TAAD.

A functional variant of SMAD4 enhances macrophage recruitment and inflammatory response via TGF-β signal activation in Thoracic aortic aneurysm and dissection.

Thoracic aortic aneurysm and dissection (TAAD) is the most fatal macro vascular disease. The mortality of 48h after diagnosis of dissection is up to approximately 50-68%. However, the genetic factors and potential mechanism underlying sporadic TAAD remain largely unknown. Our previous study suggested rs12455792 variant of SMAD4 gene significantly contributed to the increased risk and might participated the pathological progression of TAAD. This investigation aims to test (1) the associations between rs12455792 and MØ recruitment, inflammatory response in aggressiveness of TAAD, and (2) the molecular mechanism accounting for their effects. In TGF-β signaling molecular detection, rs12455792 C>T variant activated the canonical and non-canonical TGF-β mediators. It also increased the secretion of chemotactic factors of HASMCs. To confirm the impact of this change, we detected MØ recruitment and infiltration in HASMCs and aortic tissues of TAAD patients. We found that MØ recruitment in cells and tissues with rs12455792 variant genotypes was increased than that in wild type groups. Moreover, rs12455792 variant increased M1 type inflammatory response, which might contribute much to TAAD progression. To mimic the SMAD4 suppression effect of rs12455792 in vivo, we constructed the SMAD4 KD mouse. After induction with Ang II for 4w, the thoracic aorta dilatation and vascular remodeling were more serious than that of wild type group. In conclusion, rs12455792 increased MØ recruitment, M1 type inflammatory response via activated TGF-β signaling, and further promoted vascular remodeling and pathological progress of TAAD.

Downregulation of ASPP2 promotes gallbladder cancer metastasis and macrophage recruitment via aPKC-\u03b9/GLI1 pathway

Gallbladder cancer (GBC) is a highly malignant bile duct cancer with poor prognosis due to early invasion and metastasis. However, the molecular mechanisms through which GBC cells interact with the tumor microenvironment (TME) remain poorly understood. Here, we examined the role of the tumor suppressor apoptosis-stimulating of p53 protein 2 (ASPP2) in regulating GBC invasion and metastasis and macrophage recruitment. The clinicopathological significance of ASPP2 expression was measured by immunohistochemical analysis in 72 patients with GBC. Lentivirus-mediated knockdown or overexpression of ASPP2 was used to investigate the biological functions and molecular mechanisms of ASPP2 in GBC cells. Our data showed that downregulation of ASPP2 in patients with GBC was linked to poor prognosis. Knockdown of ASPP2 induced epithelial–mesenchymal transition (EMT) in GBC cells and influenced the TME. Mechanistically, we further confirmed that ASPP2 affected the expression and protein binding between atypical protein kinase C (aPKC)-ι and glioma-associated oncogene homolog 1 (GLI1). ASPP2 also induced C−C motif chemokine ligand (CCL) 2, CCL5, and tumor necrosis factor-α secretion by cancer cells, thereby promoting macrophage recruitment. The latter also induced EMT-like changes in GBC. Furthermore, ASPP2 deficiency regulated GLI1 transcriptional activity via the noncanonical Hedgehog (Hh) pathway and aPKC-ι/GLI1 signaling loop and promoted GLI1 nuclear localization and binding to the promoters of target genes. Our findings revealed that downregulation of ASPP2 promoted GBC invasion and metastasis through the aPKC-ι/GLI1 pathway and enhanced macrophage recruitment. Thus, ASPP2/aPKC-ι/GLI1 pathway may be a potential therapeutic target for the treatment of GBC.

Increased B3GALNT2 in hepatocellular carcinoma promotes macrophage recruitment via reducing acetoacetate secretion and elevating MIF activity

BackgroundHepatocellular carcinoma (HCC) ranks as the sixth most prevalent cancer and the third leading cause of tumor-related death, so it is urgently needed to discover efficient markers and targets for therapy. β-1,3-N-acetylgalactosaminyltransferase II (B3GALNT2) belongs to the β-1,3-glycosyltransferases (b3GT) family and has been reported to regulate development of both normal and tumor tissues. However, studies on the functions of B3GALNT2 in cancer are quite limited. Here we investigated the potential role of B3GALNT2 in HCC progression.MethodsWestern blot, qPCR, and immunohistochemistry assays were performed to quantify the relative expression of B3GALNT2 in HCC. The functions of B3GALNT2 in tumor progression were evaluated in HCC cell lines and nude mice. Metabolomics analysis was applied to detect alternatively expressed small molecules. Enzyme activity assays were employed to determine the tautomerase activity of macrophage inhibitory factor (MIF).ResultsFor expression analysis, higher levels of B3GALNT2 were observed in tumor tissues compared with adjacent normal tissues, and upregulation of B3GALNT2 correlated with increased tumor size and worse overall survival. Changing levels of B3GALNT2 did not influence cell viability in vitro but promoted tumor growth via enhancing macrophage recruitment in vivo. Furthermore, acetoacetate was identified as a key molecule in B3GALNT2-mediated macrophage recruitment. Mechanistically, B3GALNT2 downregulated expression of enzymes involved in acetoacetate-related metabolism, and reduction of acetoacetate revived MIF activity, thus promoting macrophage recruitment.ConclusionsThis study evaluated B3GALNT2 as a tumor marker in HCC and revealed functions of B3GALNT2 in metabolic transformation and microenvironmental remodeling in HCC. Mechanistically, B3GALNT2 reduced expression of some metabolic enzymes and thus downregulated levels of secreted acetoacetate. This relieved the activity of MIF and enhanced macrophage recruitment to promote tumor growth.