OBJECTIVE: To distinguish whether idiopathic intracranial hypertension (IIH) is a condition predisposing to multiple sclerosis (MS) or an isolated disease, the current gene transcription factor Activator Protein-1 (AP-1) was evaluated with its potential to differentiate both diseases.
BACKGROUND: The aim of this study was to investigate the use of AP-1 as biomarkers for the discrimination of IIH and MS.
METHODS: AP-1, TNF-α, and IL-6 protein values in the CSF of the cases were evaluated by the ELISA method. The numerical measures of the groups and the ability of AP-1 to distinguish the groups were analyzed with the ROC curve.
RESULTS: There was no difference between the groups in CSF TNF-α, IL-6, CSF, and serum biochemistry analyses. However, it was determined that the AP-1 concentration (pg/ml) was significantly higher in the IIH group, the sensitivity of AP-1 in separating those with IIH was 75%, and the specificity in separating those with MS was 60% in those with an AP-1 concentration of 606.5 and above.
CONCLUSIONS: According to our results, the fact that CSF TNF-α and IL-6 values did not differ in IIH compared to MS revealed that IIH could not methodologically control MS, and AP-1 was a supportive parameter in differentiating both diseases (Tab. 2, Fig. 1, Ref. 31).

Overwhelming macrophage M1 polarization induced by malfunction of the renin-angiotensin-aldosterone system (RAAS) initiates inflammatory responses, which play a crucial role in various cardiovascular diseases. However, the underlying regulatory mechanism remains elusive. Here, we identified adaptor protein HIP-55 as a critical regulator of macrophage M1 polarization. The expression of HIP-55 was upregulated in M1 macrophage induced by Ang II. Overexpression of HIP-55 significantly promoted Ang II-induced macrophage M1 polarization, whereas genetic deletion of HIP-55 inhibited the Ang II-induced macrophage M1 polarization. Mechanistically, HIP-55 facilitated activator protein-1 (AP-1) complex activation induced by Ang II via promoting ERK1/2 and JNK phosphorylation. Moreover, blocking AP-1 complex activation can attenuate the function of HIP-55 in macrophage polarization. Collectively, our results reveal the role of HIP-55 in macrophage polarization and provide potential therapeutic insights for cardiovascular diseases associated with RAAS dysfunction.

Active vitamin D derivatives (VDDs)-1α,25-dihydroxyvitamin D3/D2 and their synthetic analogs-are well-known inducers of cell maturation with the potential for differentiation therapy of acute myeloid leukemia (AML). However, their dose-limiting calcemic activity is a significant obstacle to using VDDs as an anticancer treatment. We have shown that different activators of the NF-E2-related factor-2/Antioxidant Response Element (Nrf2/ARE) signaling pathway, such as the phenolic antioxidant carnosic acid (CA) or the multiple sclerosis drug monomethyl fumarate (MMF), synergistically enhance the antileukemic effects of various VDDs applied at low concentrations in vitro and in vivo. This study aimed to investigate whether glutathione, the major cellular antioxidant and the product of the Nrf2/ARE pathway, can mediate the Nrf2-dependent differentiation-enhancing activity of CA and MMF in HL60 human AML cells. We report that glutathione depletion using L-buthionine sulfoximine attenuated the enhancing effects of both Nrf2 activators concomitant with downregulating vitamin D receptor (VDR) target genes and the activator protein-1 (AP-1) family protein c-Jun levels and phosphorylation. On the other hand, adding reduced glutathione ethyl ester to dominant negative Nrf2-expressing cells restored both the suppressed differentiation responses and the downregulated expression of VDR protein, VDR target genes, as well as c-Jun and P-c-Jun levels. Finally, using the transcription factor decoy strategy, we demonstrated that AP-1 is necessary for the enhancement by CA and MMF of 1α,25-dihydroxyvitamin D3-induced VDR and RXRα protein expression, transactivation of the vitamin D response element, and cell differentiation. Collectively, our findings suggest that glutathione mediates, at least in part, the potentiating effect of Nrf2 activators on VDDs-induced differentiation of AML cells, likely through the positive regulation of AP-1.

The immunomodulatory drug lenalidomide, which is now widely used for the treatment of multiple myeloma (MM), exerts pharmacological action through the ubiquitin-dependent degradation of IKZF1 and subsequent down-regulation of interferon regulatory factor 4 (IRF4), a critical factor for the survival of MM cells. IKZF1 acts principally as a tumour suppressor via transcriptional repression of oncogenes in normal lymphoid lineages. In contrast, IKZF1 activates IRF4 and other oncogenes in MM cells, suggesting the involvement of unknown co-factors in switching the IKZF1 complex from a transcriptional repressor to an activator. The transactivating components of the IKZF1 complex might promote lenalidomide resistance by residing on regulatory regions of the IRF4 gene to maintain its transcription after IKZF1 degradation.
To identify unknown components of the IKZF1 complex, we analyzed the genome-wide binding of IKZF1 in MM cells using chromatin immunoprecipitation-sequencing (ChIP-seq) and screened for the co-occupancy of IKZF1 with other DNA-binding factors on the myeloma genome using the ChIP-Atlas platform.
We found that c-FOS, a member of the activator protein-1 (AP-1) family, is an integral component of the IKZF1 complex and is primarily responsible for the activator function of the complex in MM cells. The genome-wide screening revealed the co-occupancy of c-FOS with IKZF1 on the regulatory regions of IKZF1-target genes, including IRF4 and SLAMF7, in MM cells but not normal bone marrow progenitors, pre-B cells or mature T-lymphocytes. c-FOS and IKZF1 bound to the same consensus sequence as the IKZF1 complex through direct protein-protein interactions. The complex also includes c-JUN and IKZF3 but not IRF4. Treatment of MM cells with short-hairpin RNA against FOS or a selective AP-1 inhibitor significantly enhanced the anti-MM activity of lenalidomide in vitro and in two murine MM models. Furthermore, an AP-1 inhibitor mitigated the lenalidomide resistance of MM cells.
C-FOS determines lenalidomide sensitivity and mediates drug resistance in MM cells as a co-factor of IKZF1 and thus, could be a novel therapeutic target for further improvement of the prognosis of MM patients.

Chronic kidney disease (CKD) is a major health problem. Kidney fibrosis is a hallmark and final common pathway of CKD. The Hippo/yes-associated protein (YAP) pathway regulates organ size, inflammation, and tumorigenesis. Our previous study demonstrated tubular YAP activation by tubule-specific double knockout of mammalian STE20-like protein kinase 1/2 (Mst1/2) induced CKD in mice, but the underlying mechanisms remain to be fully elucidated. Activator protein (AP)-1 activation was found to promote tubular atrophy and tubulointerstitial fibrosis. Therefore, we studied whether YAP regulates AP-1 expression in the kidney. We found that expression of various AP-1 components was induced in kidneys subjected to unilateral ureteric obstruction and in Mst1/2 double knockout kidneys, and these inductions were blocked by deletion of Yap in tubular cells, with Fosl1 being most affected compared with other AP-1 genes. Inhibition of Yap also most highly suppressed Fosl1 expression among AP-1 genes in HK-2 and IMCD3 renal tubular cells. YAP bound to the Fosl1 promoter and promoted Fosl1 promoter-luciferase activity. Our results suggest that YAP controls AP-1 expression and that Fosl1 is the primary target of YAP in renal tubular cells.NEW & NOTEWORTHY Yes-associated protein (YAP) activation leads to tubular injury, renal inflammation, and fibrosis, but the underlying mechanisms are not fully understood. We now provide genetic evidence that YAP promotes activator protein-1 expression and that Fosl1 is the primary target of YAP in renal tubular cells.

Nuclear factor of activated T cells (NFAT) is a transcription factor essential for immunological and other biological responses. To develop analyzing system for NFAT activity in vitro and in vivo, we generated reporter mouse lines introduced with NFAT-driven enhanced green fluorescent protein (EGFP) expressing gene construct. Six tandem repeats of -286 to -265 of the human IL2 gene to which NFAT binds in association with its co-transcription factor, activator protein (AP)-1, was conjunct with thymidine kinase minimum promoter and following EGFP coding sequence. Upon introduction of the resulting reporter cassette into C57BL/6 fertilized eggs, the transgenic mice were obtained. Among 7 transgene-positive mice in 110 mice bone, 2 mice showed the designated reporter mouse character. Thus, the EGFP fluorescence of CD4+ and CD8+ T cells in these mice was enhanced by stimulation through CD3 and CD28. Each of phorbol 12-myristate 13-acetate (PMA) and ionomycin (IOM) stimulation weakly but their combined stimulation strongly enhanced EGFP expression. The stimulation-induced EGFP upregulation was also observed following T cell subset differentiation in a different manner. The EGFP induction by PMA + IOM stimulation was more potent than that by CD3/CD28 stimulation in helper T (Th)1, Th2, Th9, and regulatory T cells, while both stimulation conditions displayed the equivalent EGFP induction in Th17 cells. Our NFAT reporter mouse lines are useful for analyzing stimulation-induced transcriptional activation mediated by NFAT in cooperation with AP-1 in T cells.

Objective: To investigate the effect of ubiquitin mutation at position 331 of tumor necrosis factor receptor related factor 6 (TRAF6) on the biological characteristics of colorectal cancer cells and its mechanism. Methods: lentivirus wild type (pCDH-3×FLAG-TRAF6) and mutation (pCDH-3×FLAG-TRAF6-331mut) of TRAF6 gene expression plasmid with green fluorescent protein tag were used to infect colorectal cancer cells SW480 and HCT116, respectively. The infection was observed by fluorescence microscope, and the expressions of TRAF6 and TRAF6-331mut in cells was detected by western blot. Cell counting kit-8 (CCK-8) and plate cloning test were used to detect the proliferation ability of colorectal cancer cells in TRAF6 group and TRAF6-331mut group, cell scratch test to detect cell migration, Transwell chamber test to detect cell migration and invasion, immunoprecipitation to detect the ubiquitination of TRAF6 and TRAF6-331mut with ubiquitinof lysine binding sites K48 and K63. Western blot was used to detect the effects of TRAF6 and TRAF6-331mut over expression on the nuclear factor kappa-B (NF-κB) and mitogen activated protein kinase mitogen-activated protein kinase (MAPK)/activating protein-1(AP-1) signal pathway. Results: The successful infection of colorectal cancer cells was observed under fluorescence microscope. Western blot detection showed that TRAF6 and TRAF6-331mut were successfully expressed in colorectal cancer cells. The results of CCK-8 assay showed that on the fourth day, the absorbance values of HCT116 and SW480 cells in TRAF6-331mut group were 1.89±0.39 and 1.88±0.24 respectively, which were lower than those in TRAF6 group (2.09±0.12 and 2.17±0.45, P=0.036 and P=0.011, respectively). The results of plate colony formation assay showed that the number of clones of HCT116 and SW480 cells in TRAF6-331mut group was 120±14 and 85±14 respectively, which was lower than those in TRAF6 group (190±21 and 125±13, P=0.001 and P=0.002, respectively). The results of cell scratch test showed that after 48 hours, the percentage of wound healing distance of HCT116 and SW480 cells in TRAF6-331mut group was (31±12)% and (33±14)%, respectively, which was lower than those in TRAF6 group [(43±13)% and (43±7)%, P=0.005 and 0.009, respectively]. The results of Transwell migration assay showed that the migration numbers of HCT116 and SW480 cells in TRAF6-331mut group were significantly lower than those in TRAF6 group (P<0.001 and P<0.002, respectively). The results of Transwell invasion assay showed that the number of membrane penetration of HCT116 and SW480 cells in TRAF6-331mut group was significantly lower than those in TRAF6 group (P=0.008 and P=0.009, respectively). The results of immunoprecipitation detection showed that the ubiquitin protein of K48 chain pulled by TRAF6-331mut was lower than that of wild type TRAF6 in 293T cells co-transfected with K48 (0.57±0.19), and the ubiquitin protein of K63 chain pulled down by TRAF6-331mut in 293T cells co-transfected with K63 was lower than that of wild type TRAF6 (0.89±0.08, P<0.001). Western blot assay showed that the protein expression levels of NF-κB, p-NF-κB and p-AP-1 in TRAF6-331mut-HCT116 cells were 0.63±0.08, 0.42±0.08 and 0.60±0.07 respectively, which were lower than those in TRAF6-HCT116 cells (P=0.002, P<0.001 and P<0.001, respectively). The expression level of AP-1 protein in TRAF6-HCT116 cells was 0.89±0.06, compared with that in TRAF6-HCT116 cells. The difference was not statistically significant (P>0.05). The protein expression levels of NF-κB, p-NF-κB and p-AP-1 in TRAF6-331mut-SW480 cells were 0.50±0.06, 0.51±0.04, 0.48±0.02, respectively, which were lower than those in TRAF6-SW480 cells (all P<0.001). There was no significant difference in AP-1 protein expression between TRAF6-331mut-SW480 cells and TRAF6-SW480 cells. Conclusion: The ubiquitin site mutation of TRAF6 gene at 331 may prevent the binding of TRAF6 and ubiquitin lysine sites K48 and K63, and then affect the expressions of proteins related to downstream NF-κB and MAPK/AP-1 signal pathways, and inhibit the proliferation, migration and invasion of colorectal cancer cells.
目的： 探讨肿瘤坏死因子受体相关因子6(TRAF6)第331位泛素化位点突变对结直肠癌细胞生物学特征的影响及其相关机制。 方法： 将带有绿色荧光蛋白标签的TRAF6基因表达质粒的慢病毒(pCDH－3×FLAG－TRAF6)和突变质粒慢病毒(pCDH－3×FLAG －TRAF6－331mut)分别感染结直肠癌细胞SW480和HCT116，荧光显微镜观察细胞感染情况，Western blot检测TRAF6和TRAF6－331mut在细胞中的表达。采用细胞计数试剂盒8法和平板克隆实验检测TRAF6组和TRAF6－331mut组结直肠癌细胞的增殖能力，细胞划痕实验检测细胞的迁移能力，Transwell小室实验检测细胞的迁移和侵袭能力，免疫共沉淀方法检测TRAF6和TRAF6－331mut与泛素的赖氨酸结合位点K48和K63的泛素化作用，Western blot检测过表达TRAF6和TRAF6－331mut对核因子κB(NF－κB)和丝裂原活化蛋白激酶(MAPK)/激活蛋白1(AP－1)信号通路的影响。 结果： 荧光显微镜下观察到病毒成功感染结直肠癌细胞。Western blot检测显示，TRAF6和TRAF6－331mut在结直肠癌细胞中成功表达。CCK－8法检测结果显示，到第4天，TRAF6－331mut组HCT116和SW480细胞的A值分别为1.89±0.39和1.88±0.24，均低于TRAF6组(分别为2.09±0.12和2.17±0.45，P值分别为0.036和0.011)。平板克隆形成实验结果显示，TRAF6－331mut组HCT116和SW480细胞的克隆数分别为(120±14)个和(85±14)个，均低于TRAF6组[分别为(190±21)个和(125±13)个，P值分别为0.001和0.002]。细胞划痕实验结果显示，48 h后，TRAF6－331mut组HCT116和SW480细胞的伤口愈合距离百分比分别为(31±12)%和(33±14)%，均低于TRAF6组[分别为(43±13)%和(43±7)%，P值分别为0.005和0.009]。Transwell迁移实验结果显示，TRAF6－331mut组HCT116和SW480细胞的迁移数分别为(104±13)个和(107±12)个，均低于TRAF6组[分别为(172±19)个和(138±16)个，P值分别为<0.001和0.002]。Transwell侵袭实验结果显示，TRAF6－331mut组HCT116和SW480细胞的穿膜数分别为(103±17)个和(92±13)个，均低于TRAF6组[分别为(177±20)个和(127±18)个，P值分别为0.008和0.009]。免疫共沉淀法检测结果显示，在与K48共转染的293T细胞中，被TRAF6－331mut下拉的K48链泛素蛋白的表达量为0.57±0.19，低于野生型TRAF6下拉的K48链泛素蛋白的表达量(0.84±0.04，P＝0.014)；在与K63共转染的293T细胞中，被TRAF6－331mut下拉的K63链泛素蛋白的表达量为0.31±0.13，低于野生型TRAF6下拉的K63链泛素蛋白的表达量(0.89±0.08，P<0.001)。Western blot检测显示，TRAF6－331mut－HCT116细胞中NF－κB、p－NF－κB和p－AP－1蛋白表达水平分别为0.63±0.08、0.42±0.08和0.60±0.07，低于TRAF6－HCT116细胞(均为1.00±0.00，P值分别为0.002、<0.001和<0.001)，AP－1蛋白表达水平为0.89±0.06，与TRAF6－HCT116细胞(1.00±0.00)比较，差异无统计学意义(P＝0.051)；TRAF6－331mut－SW480细胞中NF－κB、p－NF－κB和p－AP－1蛋白表达水平分别为0.50±0.06、0.51±0.04和0.48±0.02，低于TRAF6－SW480细胞(均为1.00±0.00，均P<0.001)，AP－1蛋白表达水平为0.90±0.06，与TRAF6－ SW480细胞(1.00±0.00)比较，差异无统计学意义(P＝0.087)。 结论： TRAF6基因第331泛素化位点突变可能阻止了TRAF6与泛素赖氨酸位点K48和K63的结合，进而影响下游NF－κB和MAPKs/AP－1信号通路相关蛋白的表达，抑制结直肠癌细胞的增殖、迁移和侵袭能力。.

Ultraviolet B (UVB) exposure causes a breakdown of collagen, oxidative stress, and inflammation. UVB activates mitogen-activated protein kinase (MAPK), activator protein-1 (AP-1), and matrix metalloproteinases (MMPs). In this study, we evaluated 2,2\'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radical scavenging activity and the photoprotective effect of lactic acid bacteria LAB strains, including Lactobacillus, Bifidobacterium, and Streptococcus genera in UVB-exposed skin fibroblasts. Nine LAB strains displayed antioxidant activity by regulating superoxide dismutase in UVB-exposed skin fibroblasts. Four LAB strains (MG4684, MG5368, MG4511, and MG5140) recovered type I procollagen level by inhibiting MMPs, MAPK, and AP-1 protein expression. Additionally, these four strains reduced the expression of proinflammatory cytokines by inhibiting oxidative stress. Therefore, L. fermentum MG4684, MG5368, L. rhamnosus MG4511, and S. thermophilus MG5140 are potentially photoprotective.

Understanding the neuro-molecular mechanisms that mediate the quantity of daily physical activity (PA) level is of medical significance, given the tremendous health benefits associated with greater physical activity. Here, we examined the effects of intra-nucleus accumbens (NAc) inhibition of activator protein-1 (AP-1), an important transcriptional factor downstream of cAMP response element binding protein (CREB; a reward-related transcriptional regulator), on voluntary wheel running behavior in wild-type (WT) and low voluntary running (LVR) female rats. Transcriptome analysis of the nucleus accumbens (NAc; a brain region critical for PA reward and motivation) was performed to further determine molecular responses to intra-NAc AP-1 inhibition in these rat lines. Within WT rats, intra-NAc AP-1 inhibition caused a significant decrease in overnight running distance in comparison to control rats (p = 0.009). Transcriptomic and bioinformatic analysis in WT rats identified involvement of gene products that regulate cellular proliferation and development, which were cellular processes regulated by AP-1. In contrast to above decreased WT distances, intra-NAc AP-1 inhibition in LVR rats increased nightly running distance in comparison to LVR control rats (p = 0.0008). Further analysis identified gene products that are associated with regulating intracellular Ca2+ homeostasis, calcium ion binding and neuronal excitability. In short, our study aims to gain a comprehensive understanding of transcriptional profile that was due to AP-1 inhibition in NAc, in which it could not only enhance the knowledge regarding molecular regulatory loops within NAc for modulating voluntary running behavior, but also provide further insights into molecular targets for future investigations.

Aluminum (Al) is a neurotoxin that gradually accumulates in the brain in human life, resulting in oxidative brain injury related to Alzheimer\'s disease (AD) and other diseases. In this study, the learning and memory of rats exposed to different aluminum concentrations (0.0 g/L, 2.0 g/L, 4.0 g/L, and 8.0 g/L) were studied, and the learning and memory of rats were observed by shuttle box experiment. With hematoxylin and eosin staining, Western blot, immunofluorescence, and RT-PCR, the morphology of nerve cells in the hippocampus of rat brain were observed, and the levels of activator protein-1 (AP-1) gene and protein, nerve growth factor (NGF), neurotrophin-3 (NT3), glial cell line-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF) gene and protein level, etc. The experimental results showed that subchronic aluminum exposure damaged learning and memory in rats. The cognitive function damage in rats was more evident after increasing the aluminum intake dose. The more aluminum intake, the more pronounced the histological changes in the hippocampus will be. The expression level and protein content of neurotrophic factors in the hippocampus of rats showed a negative correlation with aluminum intake. In this experiment, we explored the mechanism of aluminum exposure in learning and memory disorders, and provided some data reference for further elucidation of the damage mechanism of aluminum on the nervous system and subsequent preventive measures.