关键词： alcohol   monocyte   macrophage   LPS   inflammation  

摘要： Discussion on the role of ATF3 in LPS tolerance during binge drinking, and its interaction with cofactor HDAC1.

关键词： innate immunity   binge drinking   TLR4 tolerance   HDAC1  

摘要： Acute ethanol exposure decreases the production of LPS-induced TNF-, and the migration of monocytes and macrophages via ATF3. Binge drinking represses host innate immunity and leads to a high risk of infection. Acute EtOH-pretreated macrophages exhibit a decreased production of proinflammatory mediators in response to LPS. ATF3 is induced and counter-regulates the LPS/TLR4 inflammatory cascade. Here, we investigated the potential role of ATF3 in LPS tolerance in acute ethanol-pretreated macrophages. We found that there was an inverse correlation between ATF3 and LPS-induced TNF- production in acute ethanol-pretreated murine monocytes and macrophages. The knockdown of ATF3 attenuated the inhibitory effects of acute ethanol treatment on LPS-induced TNF- production. Furthermore, ChIP assays and co-IP demonstrated that ATF3, together with HDAC1, negatively modulated the transcription of TNF-. In binge-drinking mice challenged with LPS, an up-regulation of ATF3 and HDAC1 and a concomitant decrease in TNF- were observed. Given that HDAC1 was concomitantly induced in acute ethanol-exposed monocytes and macrophages, we used the HDACi TSA or silenced HDAC1 to explore the role of HDAC1 in acute ethanol-treated macrophages. Our results revealed that TSA treatment and HDAC1 knockdown prevented acute ethanol-induced ATF3 expression and the inhibition of TNF- transcription. These data indicated a dual role for HDAC1 in acute ethanol-induced LPS tolerance. Furthermore, we showed that the induction of ATF3 led to the impaired migration of BM monocytes and macrophages. Overall, we present a novel role for ATF3 in the inhibition of LPS-induced TNF- and in the impairment of monocyte and macrophage migration.

关键词： ATF3   inflammatory   lipopolysaccharide   rHDL  

摘要： Activating transcription factor 3 (ATF3) is a TLR-induced repressor that plays an important role in the inhibition of specific inflammatory signals. We previously constructed recombinant high density lipoproteins (rHDL) (including rHDL(WT), rHDL(M), rHDL(228) and rHDL(74)) and found that rHDL(74) had a strong anti-inflammatory ability. In the present study, we investigate the roles of recombinant apolipoprotein A-I (ApoA-I) (rHDL(WT)) and its cysteine mutant HDLs (rHDL(M), rHDL(228) and rHDL(74)) on ATF3 function in RAW264.7 cells stimulated by lipopolysaccharide. Our results showed that compared with the LPS group, rHDL(74) can decrease the level of TNF-alpha and IL-6, whereas rHDL(228) increases their expression levels. RT-PCR and Western blotting results showed that compared with the LPS group, rHDL(74), rHDL(WT) and rHDL(M) can markedly increase the expression level of ATF3, whereas the level of ATF3 decreases in the rHDL(228) group. In summary, the different anti-inflammatory mechanisms of the ApoA-I cysteine mutants might be associated with the regulation of ATF3 level.

关键词： ATF3   alpha(2)delta-1 subunit   Chronic pain   Formalin test   Neuropathic pain  

摘要： The purpose of this study was to investigate whether 1%, 2% or 5% formalin injection produce hypersensitivity with characteristics of the neuropathic pain induced by spinal nerve injury. Formalin injection (1%, 2% and 5%) produced concentration-dependent long-lasting (at least 14 days) mechanical allodynia and hyperalgesia in both paws. Likewise, L5/L6 spinal nerve ligation induced allodynia and hyperalgesia in both paws. The intensity of hypersensitivity was greater in the ipsilateral than in the contralateral paw in all models. Systemic gabapentin or morphine completely reduced 1% formalin-induced hypersensitivity. In contrast, both drugs were not able to fully diminish 2-5% formalin- and nerve injury-induced hypersensitivity. Indomethacin produced a significant effect in the chronic 1% formalin test. Conversely, this drug did not modify 2 or 5% formalin- and nerve injury induced hypersensitivity. Spinal nerve injury and 2-5%, but not 1%, formalin injection enhanced ATF3 protein expression and immunofluorescence in dorsal root ganglia (DRG) in a time-dependent manner. Furthermore, 2-5%, but not 1%, formalin injection or spinal nerve injury also enhanced alpha(2)delta-1 subunit protein levels in DRG. Our results suggest that 5% and, at lesser extent, 2% formalin injection produces long-lasting hypersensitivity with a pharmacological and molecular pattern that resembles neuropathic pain induced by spinal nerve ligation.

关键词： AP1 transcription factor (AP-1)   arthritis   cell signaling   chondrocyte   inflammation   matrix metalloproteinase (MMP)  

摘要： Irreversible breakdown of cartilage extracellular matrix (ECM) by the collagenase matrix metalloproteinase 13 (MMP13) represents a key event in osteoarthritis (OA) progression. Although inflammation is most commonly associated with inflammatory joint diseases, it also occurs in OA and is thus relevant to the prevalent tissue destruction. Here, inflammation generates a cFOS AP-1 early response that indirectly affects MMP13 gene expression. To ascertain a more direct effect on prolonged MMP13 production we examined the potential molecular events occurring between the rapid, transient expression of cFOS and the subsequent MMP13 induction. Importantly, we show MMP13 mRNA expression is mirrored by nascent hnRNA transcription. Employing ChIP assays, cFOS recruitment to the MMP13 promoter occurs at an early stage prior to gene transcription and that recruitment of transcriptional initiation markers also correlated with MMP13 expression. Moreover, protein synthesis inhibition following early FOS expression resulted in a significant decrease in MMP13 expression thus indicating a role for different regulatory factors modulating expression of the gene. Subsequent mRNA transcriptome analyses highlighted several genes induced soon after FOS that could contribute to MMP13 expression. Specific small interfering RNA-mediated silencing highlighted that ATF3 was as highly selective for MMP13 as cFOS. Moreover, ATF3 expression was AP-1(cFOS/cJUN)-dependent and expression levels were maintained after the early transient cFOS response. Furthermore, ATF3 bound the proximal MMP13 AP-1 motif in stimulated chondrocytes at time points that no longer supported binding of FOS. Consequently, these findings support roles for both cFOS (indirect) and ATF3 (direct) in effecting MMP13 transcription in human chondrocytes.

关键词： 慢性阻塞性肺疾病   活化转录因子3   活化转录因子4   γ-谷氨酰半胱氨酸合成酶  

摘要： 目的探讨慢性阻塞性肺疾病(简称慢阻肺)患者肺组织中活化转录因子3(ATF3)、活化转录因子4(ATF4)的表达变化,以及ATF3和ATF4对γ-谷氨酰半胱氨酸合成酶(γ-GCS)表达的影响,探讨其在慢阻肺发病中的作用。方法收集伴或不伴慢阻肺并行肺叶切除的肺癌患者临床肺组织标本40例(慢阻肺组和对照组各20例),取材标本均为远离原发肺癌病灶5 cm以上、肉眼观察无肺癌浸润的外周肺组织。所有患者术前均详细询问病史,进行体格检查、胸部X线片或肺部CT以及肺功能检测。应用原位杂交及免疫组化检测患者肺组织中ATF3、ATF4、γ-GCS重链亚基(γ-GCS-HS)m RNA及蛋白的表达,应用免疫共沉淀法(CO-IP)检测ATF3、ATF4与γ-GCS-HS蛋白之间的相互作用,并对ATF3、ATF4 m RNA及蛋白与γ-GCS-HS m RNA及蛋白进行相关分析。结果慢阻肺患者肺组织中ATF3、ATF4、γ-GCS-HS m RNA及蛋白呈强阳性表达,较对照组显著升高(P<0.01)。在γ-GCS-HS抗体捕获的免疫沉淀中,ATF3、ATF4抗体均可杂交出明显的蛋白条带,且慢阻肺组较对照组明显增强(P<0.01)。相关分析显示肺组织中ATF3、ATF4蛋白表达与γ-GCS-HS m RNA及蛋白表达均呈明显正相关(P<0.01);ATF3、ATF4、γ-GCS-HS蛋白表达与FEV1%pred、FEV1/FVC均呈明显正相关(P<0.01)。结论在慢阻肺患者发病过程中,氧化应激诱导转录因子ATF3和ATF4过表达,ATF3和ATF4可能通过影响γ-GCS m RNA和蛋白的表达而发挥抗氧化保护作用。

关键词： 转录激活因子3   急性肺损伤   趋化因子CXCL1   趋化因子CXCL2   巨噬细胞,肺泡   化脓性链球菌M1蛋白  

摘要： 目的探讨转录激活因子3(ATF3)在化脓性链球菌M1蛋白血清型诱导的急性肺损伤小鼠中的作用。方法 20只雌性C57/B6小鼠随机分为对照组(A组)和急性肺损伤组(B组),每组10只。20只雌性ATF3敲基因小鼠(ATF3^(-/-))随机分为对照组(C组)和急性肺损伤组(D组)。应用化脓性链球菌M1蛋白建立小鼠急性肺损伤模型,观察4组小鼠肺组织病理改变,计算肺组织湿重与干重比值,计数支气管肺泡灌洗液(BALF)中中性粒细胞数量,实时PCR方法检测小鼠肺泡巨噬细胞CXC趋化因子(CXCL1和CXCL2)mR NA的表达,ELISA法测定小鼠肺组织中CXCL1和CXCL2的浓度。结果与A组小鼠比较,B组小鼠肺组织病理改变加重、肺组织湿重与干重比值、BALF中中性粒细胞数量、肺泡巨噬细胞中CXCL1和CXCL2 mR NA表达量、肺组织CXCL1、CXCL2浓度均增加(P<0.05);与B组小鼠比较,D组小鼠肺组织病理改变加重、肺组织湿重与干重比值、BALF中中性粒细胞数量、肺泡巨噬细胞中CXCL1和CXCL2 m RNA表达量、肺组织CXCL1、CXCL2浓度均明显增加(P<0.05)。结论 ATF3对化脓性链球菌M1蛋白诱导的急性肺损伤小鼠有保护作用,可能与ATF3减少CXC趋化因子的产生、减轻中性粒细胞肺内聚集有关。

关键词： Cardiac remodeling   Pressure overload   Phenylephrine   ATF3   Macrophages   Cardiomyocytes  

摘要： Rational: Pressure overload induces adaptive and maladaptive cardiac remodeling processes in the heart. Part of the maladaptive process is the cross-talk between cardiomyocytes and macrophages which is dependent on the function of the Activating Transcription Factor 3, ATF3. Yet, the molecular mechanism involved in cardiomyocytes-macrophages communication leading tomacrophages recruitment to the heart and cardiac maladaptive remodeling is currently unknown. Methods and results: Isolated peritoneal macrophages from either wild type or ATF3-KO mice were cultured in serum free medium to collect conditioned medium (CM). CM was used to probe an antibody cytokine/chemokine array. The interferon. induced protein 10 kDa, CXCL10, was found to be enriched in wild type macrophages CM. Wild type cardiomyocytes treated with CXCL10 in vitro, resulted in significant increase in cell volume as compared to ATF3-KO cardiomyocytes. In vivo, pressure overload was induced by phenylephrine (PE) infusion using micro-osmotic pumps. Consistently, CXCL11 (CXCL10 competitive agonist) and CXCL10 receptor antagonist (AMG487) attenuated PE-dependent maladaptive cardiac remodeling. Significantly, we show that the expression of the CXCL10 receptor, CXCR3, is suppressed in cardiomyocytes andmacrophages derived from ATF3-KO mice. CXCR3 is positively regulated by ATF3 through an ATF3 transcription response element found in its proximal promoter. Finally, mice lacking CXCR3 display a significant reduction of cardiac remodeling processes following PE infusion. Conclusions: Chronic PE infusion results in a unique cardiomyocytes-macrophages cross-talk that is mediated by IFN gamma. Subsequently, macrophages that are recruited to the heart secrete CXCL10 resulting in maladaptive cardiac remodeling mediated by the CXCR3 receptor. ATF3-KO mice escape from PE-dependent maladaptive cardiac remodeling by suppressing the IFN gamma-CXCL10-CXCR3 axis at multiple levels. (C) 2016 Elsevier Ireland Ltd. All rights r

关键词： Type 2 diabetes   Cardiac remodeling   Cytokines   High fat diet   ATF3  

摘要： Aims Obesity and type 2 diabetes (T2D) trigger a harmful stress-induced cardiac remodeling process known as cardiomyopathy. These diseases represent a serious and widespread health problem in the Western world;however the underlying molecular basis is not clear. ATF3 is an ` immediate early' gene whose expression is highly and transiently induced in response to multiple stressors such as metabolic, oxidative, endoplasmic reticulum and inflammation, stressors that are involved in T2D cardiomyopathy. The role of ATF3 in diabetic cardiomyopathy is currently unknown. Our research has aimed to study the effect of ATF3 expression on cardiomyocytes, heart function and glucose homeostasis in an obesity-induced T2D mouse model. Methods and results We used wild type mice (WT) as well as mutant mice with a cardiac-specific ATF3 deficiency (ATF3-cKO). Mice were fed a high-fat diet (HFD) for 15 weeks. HFD induced high ATF3 expression in cardiomyocytes. Mice were examined for cardiac remodeling processes and the diabetic state was assessed. HFD-fed ATF3-cKO mice exhibited severe cardiac fibrosis, higher levels of heart hypertrophic markers, increased inflammation and worse cardiac function, as compared to WT mice. Interestingly, HFD-fed ATF3-cKO mice display increased hyperglycemia and reduced glucose tolerance, despite higher blood insulin levels, as compared to HFD-fed WT mice. Elevated levels of the cardiac inflammatory cytokines IL-6 and TNFa leading to impaired insulin signalling may partially explain the peripheral glucose intolerance. Conclusions Cardiac ATF3 has a protective role in dampening the HFD-induced cardiac remodeling processes. ATF3 exerts both local and systemic effects related to T2D-induced cardiomyopathy. This study provides a strong relationship between heart remodeling processes and blood glucose homeostasis.

关键词： Osteoclasts   RANKL   Activating transcription factor 3   Calcium signaling  

摘要： Activating transcription factor 3 (ATF3), a member of the ATF/cAMP response element-binding protein family of transcription factors, has been implicated in the regulation of cell proliferation and differentiation. However, whether ATF3 is involved in osteoclast differentiation and activity has not been well-studied. In the present study, we examined the role of ATF3 in osteoclast differentiation and function. ATF3 expression was down regulated during RANKL-induced osteoclast differentiation. Overexpression of ATF3 in bone marrow-derived monocyte/macrophage lineage cells (BMMs) promoted osteoclast differentiation and activity and strongly induced the expression of osteoclast genes encoding nuclear factor of activated T-cells cl (NFATc1) and tartrate-resistant acid phosphatase (TRAP) compared to that in the control group. In contrast, small interfering RNA mediated knockdown of ATF3 prevented the formation of multinucleated osteoclasts and markedly abrogated the expression of osteoclast marker genes. Mechanistically, ATF3 synergistically enhanced c-Fos- or NFAT-mediated transcriptional activity of the NFATc1 or TRAP promoter, respectively. Furthermore, ATF3 physically interacted with c-Fos and NFATc1 and enhanced the binding affinity of c-Fos and NFATc1 to the promoters. Interestingly, ATF3 is involved in calcium signaling during osteoclastogenesis. Taken together, these results suggest that ATF3 is a new co-factor of c-Fos and NFATc1 to activate osteoclast differentiation and activity. (C) 2016 Elsevier Inc. All rights reserved.