Response gene to complement 32 expression in macrophages augments paracrine stimulation-mediated colon cancer progression.
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ABSTRACT:
SUBMITTER: Zhao P
PROVIDER: S-EPMC6786990 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The majority of glioma-associated microglia/macrophages have been identified as M2-type macrophages with immune suppressive and tumor supportive action. Recently, the extracellular adenosine deaminase protein Cat Eye Syndrome Critical Region Protein 1 (CECR1) was shown to regulate macrophage maturation. In this study, we investigate the role of CECR1 in the regulation of the glioma-associated macrophage response.Expression of CECR1 was assessed in human glioma samples. CECR1-mediated macrophage response was studied in vitro, using donor derived CD14+ monocytes and the THP-1 monocytic cell line. The response of the human glioma cell line U87 to conditioned medium of macrophages preconditioned with recombinant human CECR1 or CECR1 silencing was also assessed.CECR1 was strongly expressed in high-grade gliomas (P < .001) and correlated positively with the M2 phenotype markers in tumor-associated microglia/macrophages (TAMs) (overall, P < .05). In vitro studies confirmed the presence of a significantly higher level of CECR1 expression in M2-like macrophages exposed to U87 conditioned medium (P < .001). CECR1 knockdown or stimulation of macrophages affected differentiation toward the M2-like phenotype. Stimulation of U87 cells with conditioned medium of CECR1 knockdown or stimulated macrophages affected tumor cell proliferation and migration, coinciding with altered intracellular signaling of mitogen-activated protein kinase (MAPK). In glioma tissue samples, CECR1 expression correlated with Ki67 and MAPK signaling protein.CECR1 is a potent regulator of TAM polarization and is consistently highly expressed by M2-type TAMs, particularly in high-grade glioma. Paracrine effects induced by CECR1 in M2-like TAMs activate MAPK signaling and stimulate the proliferation and migration of glioma cells.
| S-EPMC5464467 | biostudies-literature
Project description:OBJECTIVE:The objectives of this study were to determine the role of response gene to complement 32 (RGC-32) in vascular lesion formation after experimental angioplasty and to explore the underlying mechanisms. METHODS AND RESULTS:Using a rat carotid artery balloon-injury model, we documented for the first time that neointima formation was closely associated with a significantly increased expression of RGC-32 protein. Short hairpin RNA knockdown of RGC-32 via adenovirus-mediated gene delivery dramatically inhibited the lesion formation by 62% as compared with control groups 14 days after injury. Conversely, RGC-32 overexpression significantly promoted the neointima formation by 33%. Gain- and loss-of-function studies in primary culture of rat aortic smooth muscle cells (RASMCs) indicated that RGC-32 is essential for both the proliferation and migration of RASMCs. RGC-32 induced RASMC proliferation by enhancing p34(CDC2) activity. RGC-32 stimulated the migration of RASMC by inducing focal adhesion contact and stress fiber formation. These effects were caused by the enhanced rho kinase II-? activity due to RGC-32-induced downregulation of Rad GTPase. CONCLUSIONS:RGC-32 plays an important role in vascular lesion formation following vascular injury. Increased RGC-32 expression in vascular injury appears to be a novel mechanism underlying the migration and proliferation of vascular smooth muscle cells. Therefore, targeting RGC-32 is a potential therapeutic strategy for the prevention of vascular remodeling in proliferative vascular diseases.
| S-EPMC3146015 | biostudies-literature
Project description:Response gene to complement 32 (RGC-32) is a cell cycle regulator involved in the proliferation, differentiation and migration of cells and has also been implicated in angiogenesis. Here we show that RGC-32 expression in macrophages is induced by IL-4 and reduced by LPS, indicating a link between RGC-32 expression and M2 polarization. We demonstrated that the increased expression of RGC-32 is characteristic of alternatively activated macrophages, in which this protein suppresses the production of pro-inflammatory cytokine IL-6 and promotes the production of the anti-inflammatory mediator TGF-?. Consistent with in vitro data, tumor-associated macrophages (TAMs) express high levels of RGC-32, and this expression is induced by tumor-derived ascitic fluid in an M-CSF- and/or IL-4-dependent manner. Collectively, these results establish RGC-32 as a marker for M2 macrophage polarization and indicate that this protein is a potential target for cancer immunotherapy, targeting tumor-associated macrophages.
| S-EPMC4716617 | biostudies-literature
Project description:ObjectiveThe objective of this study is to determine the role and underlying mechanisms of RGC-32 (response gene to complement 32 protein) in atherogenesis.Approach and resultsRGC-32 was mainly expressed in endothelial cells of atherosclerotic lesions in both ApoE-/- (apolipoprotein E deficient) mice and human patients. Rgc-32 deficiency (Rgc32-/-) attenuated the high-fat diet-induced and spontaneously developed atherosclerotic lesions in ApoE-/- mice without affecting serum cholesterol concentration. Rgc32-/- seemed to decrease the macrophage content without altering collagen and smooth muscle contents or lesional macrophage proliferation in the lesions. Transplantation of WT (wild type) mouse bone marrow to lethally irradiated Rgc32-/- mice did not alter Rgc32-/--caused reduction of lesion formation and macrophage accumulation, suggesting that RGC-32 in resident vascular cells, but not the macrophages, plays a critical role in the atherogenesis. Of importance, Rgc32-/- decreased the expression of ICAM-1 (intercellular adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1) in endothelial cells both in vivo and in vitro, resulting in a decrease in TNF-α (tumor necrosis factor-α)-induced monocyte-endothelial cell interaction. Mechanistically, RGC-32 mediated the ICAM-1 and VCAM-1 expression, at least partially, through NF (nuclear factor)-κB signaling pathway. RGC-32 directly interacted with NF-κB and facilitated its nuclear translocation and enhanced TNF-α-induced NF-κB binding to ICAM-1 and VCAM-1 promoters.ConclusionsRGC-32 mediates atherogenesis by facilitating monocyte-endothelial cell interaction via the induction of endothelial ICAM-1 and VCAM-1 expression, at least partially, through NF-κB signaling pathway.
| S-EPMC5864544 | biostudies-literature
Project description:Response gene to complement 32 (RGC-32) is induced by activation of complement and regulates cell proliferation. To determine the mechanism of RGC-32 in angiogenesis, we examined the role of RGC-32 in hypoxia-related endothelial cell function.Hypoxia/ischemia is able to stimulate both angiogenesis and apoptosis. Hypoxia-inducible factor-1/vascular endothelial growth factor is a key transcriptional regulatory pathway for angiogenesis during hypoxia. We demonstrated that the increased RGC-32 expression by hypoxia was via hypoxia-inducible factor-1/vascular endothelial growth factor induction in cultured endothelial cells. However, overexpression of RGC-32 reduced the proliferation and migration and destabilized vascular structure formation in vitro and inhibited angiogenesis in Matrigel assays in vivo. Silencing RGC-32 had an opposing, stimulatory effect. RGC-32 also stimulated apoptosis as shown by the increased apoptotic cells and caspase-3 cleavage. Mechanistic studies revealed that the effect of RGC-32 on the antiangiogenic response was via attenuating fibroblast growth factor 2 expression and further inhibiting expression of cyclin E without affecting vascular endothelial growth factor and fibroblast growth factor 2 signaling in endothelial cells. In the mouse hind-limb ischemia model, RGC-32 inhibited capillary density with a significant attenuation in blood flow. Additionally, treatment with RGC-32 in the xenograft tumor model resulted in reduced growth of blood vessels that is consistent with reduced colon tumor size.We provide the first direct evidence for RGC-32 as a hypoxia-inducible gene and antiangiogenic factor in endothelial cells. These data suggest that RGC-32 plays an important homeostatic role in that it contributes to differentiating the pathways for vascular endothelial growth factor and fibroblast growth factor 2 in angiogenesis and provides a new target for ischemic disorder and tumor therapies.
| S-EPMC2837511 | biostudies-literature
Project description:AimsThe objectives of this study are to determine the role of response gene to complement 32 (RGC-32) in the placental angiogenesis during pregnancy and explore the underlying mechanisms.Methods and resultsRGC-32-deficient (RGC32(-/-)) mice were generated from C57BL/6 embryonic stem cells with deletion of exon 2 and 3 of the RGC-32 gene. Most of the RGC32(-/-) mice can survive. However, their body sizes were much smaller compared with their wild-type littermates when they were born. By examining the embryo development and placentas at 16.5 days post-coitum, we found that RGC32(-/-) embryos and foetal placentas were significantly smaller than the wild-type. Further analysis showed that the labyrinth zone of RGC32(-/-) placenta was smaller with defective angiogenesis. Mechanistically, vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) and placental growth factor (PlGF) were significantly down-regulated in RGC32(-/-) placentas, suggesting that VEGFR2 and PlGF may mediate RGC-32 function in placental angiogenesis. Indeed, knockdown of RGC-32 by shRNA inhibited VEGF-induced endothelial cell proliferation, migration, and tube formation while blocking VEGFR2 expression. RGC-32 appeared to regulate VEGFR2 expression via activation of NF-kB. Moreover, RGC-32 regulated trophoblasts proliferation via control of PlGF expression.ConclusionAbsence of RGC-32 caused foetal growth restriction through interrupting the placental angiogenesis, which was due to the decrease in VEGFR2 expression through the NF-kB-dependent pathway in endothelial cells and PlGF expression in trophoblasts.
| S-EPMC3746951 | biostudies-literature
Project description:The contribution of epithelial-mesenchymal transition (EMT) to human lung fibrogenesis is controversial. Here we provide evidence that ZEB1-mediated EMT in human alveolar epithelial type II (ATII) cells contributes to the development of lung fibrosis by paracrine signalling to underlying fibroblasts. Activation of EGFR-RAS-ERK signalling in ATII cells induced EMT via ZEB1. ATII cells had extremely low extracellular matrix gene expression even after induction of EMT, however conditioned media from ATII cells undergoing RAS-induced EMT augmented TGFβ-induced profibrogenic responses in lung fibroblasts. This epithelial-mesenchymal crosstalk was controlled by ZEB1 via the expression of tissue plasminogen activator (tPA). In human fibrotic lung tissue, nuclear ZEB1 expression was detected in alveolar epithelium adjacent to sites of extracellular matrix (ECM) deposition, suggesting that ZEB1-mediated paracrine signalling has the potential to contribute to early fibrotic changes in the lung interstitium. Targeting this novel ZEB1 regulatory axis may be a viable strategy for the treatment of pulmonary fibrosis.
| S-EPMC6252080 | biostudies-literature
Project description:RATIONALE:Hypertension prevalence is much higher among children and adolescents with low birth weight and greater postnatal weight gain than in individuals with normal birth weight. However, the cause and molecular mechanisms underlying this complication remain largely unknown. Our previous studies have shown that RGC-32 (response gene to complement 32)-deficient (RGC-32-/-) mice are born significantly smaller but grow faster than their WT (wild type) controls, which allows adult RGC-32-/- mice to attain body weights similar to those of control mice. OBJECTIVE:The objective of this study is to determine whether RGC-32-/- mice develop hypertension, and if so, to elucidate the underlying mechanisms. METHODS AND RESULTS:By using a radiotelemetry system, we found that RGC-32-/- mice exhibit higher mean arterial pressure than WT mice (101±4 versus 119±5 mm?Hg), which enabled us to use RGC-32-/- mice to study the mechanisms underlying low birth weight-related hypertension. The increased blood pressure in RGC-32-/- mice was associated with increased vascular tone and decreased distensibility of small resistance arteries. The increased vascular tone was because of an increase in the relative contribution of sympathetic versus parasympathetic activity and was linked to increased expression of AT1R (angiotensin II type I receptor) and ?1-AdR (?1-adrenergic receptor) in arterial smooth muscles. Mechanistically, RGC-32 regulated AT1R gene transcription by interacting with Sp1 (specificity protein 1) transcription factor and further blocking its binding to the AT1R promoter, leading to suppression of AT1R expression. The attenuation of AT1R leads to reduction in ?1-AdR expression, which was critical for the balance of sympathetic versus parasympathetic control of vascular tone. Of importance, downregulation of RGC-32 in arterial smooth muscles was also associated with low birth weight and hypertension in humans. CONCLUSIONS:Our results indicate that RGC-32 is a novel protein factor vital for maintaining blood pressure homeostasis, especially in individuals with low birth weight.
| S-EPMC6214659 | biostudies-literature
Project description:Background. Methicillin-resistant Staphylococcus aureus (MRSA) can stimulate massive cytokine release. Ketamine suppresses tumor necrosis factor (TNF) secretion by MRSA-stimulated RAW264.7 macrophages, and the mechanism likely involves N-methyl-D-aspartic acid (NMDA) receptor antagonism. The downstream effects of NMDA-mediated TNF suppression, specifically the PI3K/Akt and mTOR modulation, have not been described. Methods. RAW264.7 cells were stimulated for 18?hrs with 10(5) to 10(7)?CFU/mL inocula of either of two prototypical community-acquired- (CA-) MRSA isolates, USA300 strain LAC and USA400 strain MW2. Then we added the NMDA inhibitors ketamine or 2R-amino-5-phosphonopentanoate (AP5), NMDA substrate, LY294002, and rapamycin in various combinations. Results. NMDA inhibition suppressed TNF secretion by almost a third compared to the no-ketamine control. When NMDA substrate was added, the TNF secretion increased by 10%. Addition of LY294002 suppressed TNF production by macrophages by 20%. Rapamycin exhibited a concentration-dependent TNF induction-suppression response: induction at doses of 0.1 and 1?ng/mL and suppression at 10 and 100?ng/mL. Induction of TNF was abolished when LY294002 was added and the suppression became uniform. Ketamine-induced suppression of TNF secretion was intensified 10-15% when rapamycin was added, but not when LY294002 was added. Conclusion. These findings suggest that NMDA-induced TNF suppression can be augmented by concurrent mTOR inhibition.
| S-EPMC3474976 | biostudies-literature
Project description:Trauma associated with infection may directly trigger a neuroendocrine reaction in vivo while the hormone epinephrine is known to mediate immune responses to inflammation after injury. However, the role of epinephrine during the earliest stage of trauma still remains unclear. We therefore explored the role of epinephrine on activated macrophages under LPS stimulation in vitro as well as the mechanisms underlying its effect. Dose- and time-dependent effects of epinephrine on macrophage immune function were assessed after LPS activation. We also employed CD14 siRNA interference to investigate whether CD14 played a role in the mechanism underlying the effect of epinephrine on LPS-induced macrophage responses. Our results showed that epinephrine pretreatment (10 ng/mL) significantly promoted immune responses from LPS stimulated macrophages, including phagocytic rate, phagocytic index, TNFα/IL-1β/IL-10 secretion, and CD14 expression (P < 0.05). Moreover, TNFα/IL-1β/IL-10 levels attained their peak value 1 hour after incubation with 10 ng/mL epinephrine (P < 0.05), and CD14 siRNA transfection dramatically decreased phagocytosis and cytokine secretion by LPS-activated macrophages (P < 0.05). We therefore conclude that 10 ng/mL epinephrine enhances immune responses from macrophages under LPS stimulation and that the underlying mechanism may relate to CD14 upregulation on the surface of macrophages.
| S-EPMC4160625 | biostudies-literature