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Interplay between metabolism and chromatin signaling have been implicated in cancer initiation and progression. However, whether and how metabolic reprogramming in tumors generates specific epigenetic vulnerabilities remain unclear. Lung adenocarcinoma (LUAD) tumors frequently harbor mutations that cause aberrant activation of the NRF2 antioxidant pathway and drive aggressive and chemo-resistant disease. We performed a chromatin-focused CRISPR screen and report that NRF2 activation sensitized LUAD cells to genetic and chemical inhibition of class I histone deacetylases (HDAC). This association was consistently observed across cultured cells, syngeneic mouse models and patient-derived xenografts. HDAC inhibition causes widespread increases in histone H4 acetylation (H4ac) at intergenic regions, but also drives re-targeting of H4ac reader protein BRD4 away from promoters with high H4ac levels and transcriptional downregulation of corresponding genes. Integrative epigenomic, transcriptomic and metabolomic analysis demonstrates that these chromatin changes are associated with reduced flux into amino acid metabolism andde novonucleotide synthesis pathways that are preferentially required for the survival of NRF2-active cancer cells. Together, our findings suggest that metabolic alterations such as NRF2 activation could serve as biomarkers for effective repurposing of HDAC inhibitors to treat solid tumors.

The transcription factor Nrf2 activates transcription of cytoprotective genes during oxidative and electrophilic insults. Nrf2 activity is regulated by Keap1 in a stress-dependent manner in normal cells, and somatic loss-of-function mutations of Keap1 are known to induce constitutive Nrf2 activation, especially in lung adenocarcinomas, conferring survival and proliferative benefits to tumors. Therefore, several therapeutic strategies that aim to inhibit Nrf2 in tumors have been developed for the treatment of Nrf2-activated cancers. Here we addressed whether targeting Nrf2 activation in the microenvironment can suppress the progression of Nrf2-activated tumors. We combined two types of Keap1-flox mice expressing variable levels of Keap1 with a Kras-driven adenocarcinoma model to generate Keap1-deficient lung tumors surrounded by normal or Keap1-knockdown host cells. In this model system, activation of Nrf2 in the microenvironment prolonged the survival of Nrf2-activated tumor-bearing mice. The Nrf2-activated microenvironment suppressed tumor burden; in particular, preinvasive lesion formation was significantly suppressed. Notably, loss of Nrf2 in bone marrow–derived cells in Nrf2-activated host cells appeared to counteract the suppression of Nrf2-activated cancer progression. Thus, these results demonstrate that microenvironmental Nrf2 activation suppresses the progression of malignant Nrf2-activated tumors and that Nrf2 activation in immune cells at least partially contributes to these suppressive effects.Significance:This study clarifies the importance of Nrf2 activation in the tumor microenvironment and in the host for the suppression of malignant Nrf2-activated cancers and proposes new cancer therapies utilizing inducers of Nrf2.

Figure S1: Expression of Keap1 and Nqo1 in Keap1WT/WT, Keap1FB/FB and Keap1FA/FA mouse tissues; Figure S2: Analyses of tumor-bearing mouse cohorts; Figure S3: Origins of tumor cells in Kras::Keap1WT/WT, Kras::Keap1FB/FB and Kras::Keap1FA/FA lungs; Figure S4. Analyses of tumor-bearing Kras::Keap1FA/FA mouse cohorts that received Keap1FA/FA, Keap1WT/WT or Nrf2-/- bone marrows; Table S1: Primers and probes for qRT-PCR analyses; Table S2: Primers for analyses of recombination efficiency; Supplementary Materials and Methods (Establishment of mouse embryonic fibroblasts (MEFs), Validation of the recombination efficiency, Immunoblot analyses, Histology and Immunohistochemistry, Flow cytometry, and isolation of CD8+ T cells in tumor-bearing lungs)

We herein report an unusual case of granulomatosis with polyangiitis (GPA) in a 65-year-old man in whom relapsed disease manifested as an anterior cheek nodule. Magnetic resonance imaging indicated the differential diagnoses of the subcutaneous nodule in the patient's anterior cheek to be inflammatory granulomatous lesions with GPA, malignancy, or infectious disease. A histopathological examination ruled out malignancy and infectious diseases, and necrotizing vasculitis was suspected. The subcutaneous nodule was successfully treated using rituximab, suggesting that it was associated with GPA, secondary to vasculitis. Clinicians should be aware of the possibility of such a rare manifestation of GPA.

Multiple cancers regulate oxidative stress by activating the transcription factor NRF2 through mutation of its negative regulator KEAP1. NRF2 has been studied extensively in KEAP1-mutant cancers, however the role of this pathway in cancers with wildtype KEAP1 remains poorly understood. To answer this question, we induced NRF2 via pharmacological inactivation of KEAP1 in a panel of 50+ non-small lung cancer cell lines. Unexpectedly, marked decreases in viability were observed in >13% of the cell lines—an effect that was completely rescued by NRF2 ablation. Genome-wide and targeted CRISPR screens revealed that NRF2 induces NADH-reductive stress, through the upregulation of the NAD+-consuming enzyme ALDH3A1. Leveraging these findings, we show that cells treated with KEAP1 inhibitors or those with endogenous KEAP1 mutations are selectively vulnerable to Complex I inhibition, which impairs NADH oxidation capacity and potentiates reductive stress. Thus, we identify reductive stress as a metabolic vulnerability in NRF2-activated lung cancers.

The Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2–related factor 2 (NRF2) pathway plays a physiologic protective role against xenobiotics and reactive oxygen species. However, activation of NRF2 provides a powerful selective advantage for tumors by rewiring metabolism to enhance proliferation, suppress various forms of stress, and promote immune evasion. Genetic, epigenetic, and posttranslational alterations that activate the KEAP1/NRF2 pathway are found in multiple solid tumors. Emerging clinical data highlight that alterations in this pathway result in resistance to multiple therapies. Here, we provide an overview of how dysregulation of the KEAP1/NRF2 pathway in cancer contributes to several hallmarks of cancer that promote tumorigenesis and lead to treatment resistance. Significance: Alterations in the KEAP1/NRF2 pathway are found in multiple cancer types. Activation of NRF2 leads to metabolic rewiring of tumors that promote tumor initiation and progression. Here we present the known alterations that lead to NRF2 activation in cancer, the mechanisms in which NRF2 activation promotes tumors, and the therapeutic implications of NRF2 activation.

Summary: Aortic dissection (AD) is the acute destruction of aortic wall and is reportedly induced by inflammatory response. Here we investigated the role of smooth muscle Socs3 (a negative regulator of Janus kinases/signal transducer and activator of transcription signaling) in AD pathogenesis using a mouse model generated via β-aminopropionitrile and angiotensin II infusion. Socs3 deletion specifically in smooth muscle cells yielded a chronic inflammatory response of the aortic wall, which was associated with increased fibroblasts, reinforced aortic tensile strength, and less-severe tissue destruction. Although an acute inflammatory response is detrimental in AD, smooth muscle-regulated inflammatory response seemed protective against AD. Key Words: aortic dissection, inflammation, Jak/Stat, smooth muscle cells

Background: Aortic dissection (AD) is a catastrophic disease that occurs suddenly. The acute mortality is high and those who survived frequently suffer from serious complications. Currently, pathogenesis of AD is largely unknown, which hampers the development of effective approaches to predict the prognosis and to alleviate the progression of AD. Previous studies revealed the importance of inflammation in AD pathogenesis. Recently we found that cell proliferation occurs during the development and the progression of AD. Because cell proliferation triggers cellular senescence, which is associated with secretion of proinflammatory cytokines, we hypothesized that cellular senescence might be involved in AD pathogenesis. Objective: We investigated if cellular senescence contributes to AD development and progression in a mouse AD model. Methods and Results: A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII), where AD starts to develop in 3 days and occurs in most of the mice within 14 days. Infusion of BAPN+AngII resulted in the appearance of senescent cells that are positive for senescence-associated beta-galactosidase, and expression of senescence markers Arf and Ink4a in the aortic walls. Cellular senescence occurred in one day of BAPN+AngII infusion and was sustained throughout the observational period of 14 days. We examined the role of cellular senescence in AD pathogenesis by oral administration of ABT263 which is known as "senolytics" that eliminates senescent cells. ABT263 treatment reduced the expression of the senescence markers. In the vehicle-treated group, the mortality was 66.7% (12/18), whereas that of ABT263-treated group was 35% (14/20, P < 0.05 by log-rank test). The severity of AD, as assessed by the lesion length in vehicle group was 16.6±6.9mm, whereas that in ABT263 group was 12.2±4.2 mm (P < 0.05). Conclusions: These findings demonstrated that cellular senescence precedes AD development, and elimination of senescent cells effectively prevented AD progression and death, indicating the involvement of cellular senescence in AD pathogenesis. Therefore, cellular senescence represents a potential predictor and a therapeutic target for AD.

Background Aortic dissection (AD) is a catastrophic disease that occurs suddenly. The acute mortality is high and those who survived frequently suffer from serious complications such as aneurysm formation and distal ischemia due to progressive destruction of the aortic walls. Currently, no predictor of AD onset is available nor therapeutic intervention to specifically prevent the progressive destruction in AD, because the molecular pathogenesis is largely unknown. Clinical and experimental studies highlighted the importance of inflammation in AD, although the regulatory mechanism of inflammation remains unclear. Recently, we found that cell proliferation precedes the inflammatory response in AD. Because cell proliferation causes cellular senescence that can induce inflammatory response, we hypothesized that cellular senescence participates in AD pathogenesis. Objective We investigated if cellular senescence contributes to AD development and progression in mouse AD model. Methods and results A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII), where AD starts to develop in 3 days and occurs to most of the mice in 14 days accompanied by frequent AD rupture and death. Infusion of BAPN+AngII resulted in the induction of senescence markers Ink4a from day 3 before AD onset and persisted for the 14 days of the observational period. Cellular senescence, as demonstrated by the expression of senescence-associated beta-galactosidase, was evident in intimal endothelial cells, medial smooth muscle cells, adventitial macrophages and fibroblasts. We examined the role of cellular senescence in AD pathogenesis by oral administration of ABT263 which is known as “senolytics” that eliminates senescent cells. ABT263 treatment reduced the expression of the senescence marker, prevented the death by AD rupture, and ameliorated the severity of AD lesion compared to the vehicle treatment. Transcriptome analysis revealed that ABT treatment suppressed the immune and inflammatory response in AD. Quantitative RT-PCR confirmed that ABT treatment prevented the induction of p21Cip1, interleukin-6, several chemokines and their receptors by 3-day infusion of BAPN+AngII. Conclusions These findings demonstrated that senescence of multiple cell types precedes AD development, which is likely to induce the inflammatory response. Elimination of senescent cells effectively prevented AD progression and death. Therefore, cellular senescence represents a potential predictor and a therapeutic target for AD. Funding Acknowledgement Type of funding sources: None.

This article provides the background to the special issue by reviewing the status of traffic problems in South East Asian countries, and in particular, the case of Cambodia. The “Make Roads Safe” report by the Commission for Global Road Safety (2011) confirms traffic accidents as the primary cause of youth mortality worldwide. Thus, the United Nations declared the decade from 2011 to 2020 as the “UN Decade of Action for Road Safety 2011-2020”, promoting road safety and to reduce the number of deaths in road accidents by 2020. Furthermore, the “Sustainable Development Goals” adopted in 2015 highlight the important role of sustainable transport in tackling the exclusion of vulnerable groups. On the other hand, the World Health Organization in 2015 indicate an increase in the death rate due to traffic accidents in low-income countries since 2000. Traffic accidents were already recognized as a social problem before the 2000s in countries such as Thailand and the Philippines. At the same time, other ASEAN member states such as Vietnam and Cambodia which have experienced rapid economic growth since the 2000s are now experiencing the seriousness of traffic problems. It is said that 70% of road accidents in Thailand, Cambodia and Laos involve motorcycles and three-wheelers, but despite this situation, the regulatory framework for motorcycles remains undeveloped. In the case of Cambodia, speeding by young people remains the major cause of road deaths and this can be explained by the fact that people can now travel at a higher speed because of road developments but remaining challenges related to underdeveloped traffic legislation, and limited public awareness and knowledge of road safety are overlooked. In 2010, the Cambodian National Road Safety Action Plan 2010–2020 was drafted, aiming to halve the number of deaths in traffic accidents in 2020. However, in reality, the number of road deaths did not decrease to the level anticipated in the action plan until 2016. In this article, the authors emphasize the importance of implementing the “three Es” namely Engineering, Enforcement and Education in developing countries such as Cambodia. In particular, the authors claim that the role of education to increase people's road safety awareness is neglected compared to the other two dimensions and thus, it is highly important to raise people's road safety awareness through education among the young people. Keywords: Traffic accidents, Motorcycle, Youth, Cambodia, Developing countries, Southeast Asia

Background Aortic dissection (AD) is a serious clinical condition that frequently results in fatal outcome. Although recent studies indicate the critical role of inflammation in AD, the molecular pathogenesis of AD is still unclear. Syk is a tyrosine kinase that regulates multiple types of inflammatory cells. Syk is also reported to regulate the function of smooth muscle cells (SMCs), the major component of aortic walls. It is unknown whether and how Syk is involved in AD pathogenesis. Objective In the current study, we investigated the role of Syk in AD. Methods and results A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII) that caused progressive development of AD from day 7, reaching approximately 80% of AD incidence at day 14. Western blot analysis for activated (phosphorylated) Syk (pSyk) revealed Syk activation at day 3 of BAPN+AngII infusion, followed by transient suppression at day 7, and reactivation at day 14. Double immunofluorescence staining for pSyk and smooth muscle alpha actin showed that Syk was active not only in the infiltrating inflammatory cells, but also in SMCs in AD. Treatment of mice with fostamatinib, a specific Syk inhibitor, resulted in more severe AD compared to the vehicle treatment. The AD lesion length was 3.80±0.86 mm in the vehicle group and 8.87±1.69 mm in the fostamatinib group (P Conclusions These findings uncovered the previously unrecognized role of Syk for protecting the aortic tissue in AD pathogenesis, possibly by activating the protective mechanism of aortic walls including Stat3 in SMCs. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant from Japan Society for the Promotion of Science

Aortic dissection (AD) is a fatal disease due to the sudden destruction of the aortic medial layer. Currently, Molecular pathogenesis of AD is unknown. We investigated the role of focal adhesion kinase (FAK), a mechanosensitive signal transducer, in AD pathogenesis. We created a mouse model of AD with a continuous infusion of beta-aminopropionitrile (150 mg/kg/day), a collagen crosslink inhibitor, and angiotensin II (1,000 ng/kg/min) (BAPN + Ang II) by osmotic pumps. This AD model showed about 60% mortality within 2 weeks due to AD rupture. Immunohistochemical staining for activated FAK revealed that FAK was inactive in normal mouse aorta, but was strongly activated in the aortic walls after BAPN + Ang II infusion. Immunofluorescence staining showed that FAK was activated mainly in smooth muscle cells after the BAPN + Ang II challenge. Western blot analysis revealed that FAK was activated in 3 days after BAPN + Ang II infusion before AD development, followed by transient reduction at day 7, and re-activation after AD development at day 14. We examined the effect of PND-1186, an orally available FAK inhibitor, on the severity as determined by the AD lesion length and the mortality of AD. Mice were administered with either vehicle or PND-1186 (150 mg/kg twice daily by oral gavage) during the BAPN + Ang II challenge (n=20 for each group). Administration of PND-1186 resulted in significant reduction in the lesion length of AD (vehicle; 12.5 ± 1.65 mm, PND; 7.46 ± 1.88 mm, P

PURPOSE Cancer treatment can alter patient appearance, leading to psychological, social, and behavioral issues. This study aimed to investigate distress and difficulties related to appearance concerns in Japanese cancer patients and to identify information and support needs among them. METHODS We conducted a questionnaire survey using the Derriford Appearance Scale 59 (DAS59) among cancer patients with a prior history of chemotherapy, molecular targeted therapy, or immunotherapy, who were recruited from the Departments of Medical Oncology and Psychosomatic Medicine, Kindai University Hospital. RESULTS Participants were 114 patients with a mean age of 62.9 years; 70.2% were female, 86.0% had metastatic or locally advanced unresectable cancer, and 78.1% had concerns about some aspect of their appearance. Mean DAS59 full-scale score was 77.7 ± 36.4. Younger and female participants were found to have higher full-scale scores in univariate analysis (P

The transcription factor NF-E2-related factor 2 (Nrf2) is a key regulator of cellular defense mechanisms against oxidative stress. Multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system, is characterized by progressive demyelination and neurodegeneration induced by inflammation and oxidative stress. The induction of Nrf2 signaling has been shown to inhibit disease development and progression in the experimental autoimmune encephalomyelitis (EAE) model of MS in mice. In the present study, we performed a high-throughput screening assay using a chimeric construct of the N-terminal portion of Nrf2 fused to LacZ. Using this approach, we identified the novel Nrf2 inducer TFM-735. Using human primary cell profiling systems, we found that TFM-735 inhibited T cell proliferation and exerted immuno-modulatory effects by inhibiting the production of IL-6 and IL-17. TFM-735 also inhibited IL-17 secretion from human peripheral blood mononuclear cells stimulated with anti-CD3 and anti-CD28. In EAE mice treated with TFM-735, the expression of the Nrf2 target gene Nqo1 increased in the brain and spleen, disease severity was ameliorated, and plasma IL-17 levels decreased. Furthermore, TFM-735 inhibited luciferase activity in Wim-6 transgenic EAE mice expressing the human interleukin 6-luciferase (hIL6-BAC-Luc) reporter. Therefore, these findings indicate that TFM-735 is a potent Nrf2 inducer that inhibits inflammatory cytokine production and disease progression in mice with EAE and that TFM-735 is a promising therapeutic agent for MS.

Background Aortic dissection (AD) is a serious clinical condition with unknown etiology that frequently results in fatal outcome. Recent studies showed essential role of inflammatory response both in promoting AD and aortic aneurysm (AA). However, the difference of the molecular pathogenesis between AD and AA is unclear. Previously, we reported that Syk, a tyrosine kinase that regulates differentiation and activation of inflammatory cells, promotes AA formation in a mouse model. Objective In the current study, we investigated the role of Syk in AD. Methods and results A mouse AD model was created by continuous infusion of beta-aminopropionitrile (125 mg/kg/day) and angiotensin II (1,000 ng/min/kg) (BAPN+AngII), which caused AD in approximately 80% of mice within 14 days. Immunohistochemical staining for activated (phosphorylated) Syk (pSyk) revealed that Syk was inactive in normal mouse aorta, but was activated in the aortic walls after AD development. Double immunofluorescence staining for pSyk and smooth muscle alpha actin showed that Syk was active not only in the infiltrating inflammatory cells, but also in smooth muscle cells in AD tissue. Western blot analysis revealed that BAPN+AngII treatment caused Syk activation at 3 days before AD development, followed by transient suppression, and reactivation at 14 days after AD development. We examined the significance of Syk activation in AD by treating mice with fostamatinib, a specific Syk inhibitor, before and during BAPN+AngII infusion. Notably, fostamatinib-treated group developed more severe AD compared to the vehicle-treated group. The AD lesion length was 3.80±0.86 mm for vehicle group and 8.87±1.69 mm for fostamatinib group (P Conclusions These findings uncovered the previously unrecognized role of Syk for protecting the aortic tissue in AD pathogenesis, and suggested fundamentally different disease mechanisms of AD and AA.

Background Aortic dissection (AD) is a fatal disease where the media of the aorta suddenly fail. Currently, Molecular pathogenesis of AD is unknown. Recently, we discovered that the activity of MRTF-A, a mechanosensitive transcriptional regulator, promotes AD development. The activity of MRTF-A is regulated by mechanical stress to cells, which is transduced through focal adhesion and actin dynamics. However, it is currently unknown whether the mechanotransduction mechanism is involved in AD pathogenesis. Purpose We investigated the role of focal adhesion kinase (FAK), a signaling molecule that transduces mechanostress from focal adhesion to actin dynamics, in AD pathogenesis. Methods We created a mouse model of AD with a continuous infusion of beta-aminopropionitrile (150 mg/kg/day), a collagen crosslink inhibitor, and angiotensin II (1,000 ng/kg/min) (BAPN + AngII) by an osmotic pump. This model caused about 60% death in all mice due to AD rupture within 2 weeks. In this model, we examined the severity and mortality rate of aortic dissection after 2 weeks in mice administered with PND-1186, an orally available FAK inhibitor, and in those treated with vehicle (n=20 for each group). We performed immunochemical staining, immunofluorescence staining and Western blot for activated (phosphorylated) FAK (pFAK) to evaluate the activation status of FAK in the aortic tissue. We also performed transcriptome analysis of the aortic tissue in with and without PND-1186 with BAPN + AngII stimulation before AD development. Results Immunochemical staining revealed that FAK was inactive in normal mouse aorta, but was strongly activated in the aortic walls after AD development. Immunofluorescence staining showed that FAK was activated mainly in smooth muscle cells after AD development. Western blot analysis also revealed that FAK was activated in 3 days after BAPN + AngII infusion before AD development, followed by transient reduction at day 7, and re-activation after AD at day 14. Significantly, administration of PND-1186 resulted in a significant reduction in the severity of AD in the aortic arch (1.96±0.41 mm in vehicle group, 0.66±0.29 mm in PND group, P Conclusions These findings proved that FAK plays a central role in the pathogenesis of AD probably by transmitting pathological stress to the aortic wall to cause tissue destruction. We propose that FAK is a potential therapeutic target for limiting the fatal destruction of the aortic wall of AD.

The transcription factor Nrf2 activates transcription of cytoprotective genes during oxidative and electrophilic insults. Nrf2 activity is regulated by Keap1 in a stress-dependent manner in normal cells, and somatic loss-of-function mutations of Keap1 are known to induce constitutive Nrf2 activation, especially in lung adenocarcinomas, conferring survival and proliferative benefits to tumors. Therefore, several therapeutic strategies that aim to inhibit Nrf2 in tumors have been developed for the treatment of Nrf2-activated cancers. Here we addressed whether targeting Nrf2 activation in the microenvironment can suppress the progression of Nrf2-activated tumors. We combined two types of Keap1-flox mice expressing variable levels of Keap1 with a Kras-driven adenocarcinoma model to generate Keap1-deficient lung tumors surrounded by normal or Keap1-knockdown host cells. In this model system, activation of Nrf2 in the microenvironment prolonged the survival of Nrf2-activated tumor-bearing mice. The Nrf2-activated microenvironment suppressed tumor burden; in particular, preinvasive lesion formation was significantly suppressed. Notably, loss of Nrf2 in bone marrow–derived cells in Nrf2-activated host cells appeared to counteract the suppression of Nrf2-activated cancer progression. Thus, these results demonstrate that microenvironmental Nrf2 activation suppresses the progression of malignant Nrf2-activated tumors and that Nrf2 activation in immune cells at least partially contributes to these suppressive effects. Significance: This study clarifies the importance of Nrf2 activation in the tumor microenvironment and in the host for the suppression of malignant Nrf2-activated cancers and proposes new cancer therapies utilizing inducers of Nrf2.

Aortic dissection (AD) is a serious clinical condition that is unpredictable and frequently results in fatal outcome. Although rapamycin, an inhibitor of mechanistic target of rapamycin (mTOR), has been reported to be effective in preventing aortopathies in mouse models, its mode of action has yet to be clarified. A mouse AD model that was created by the simultaneous administration of β-aminopropionitrile (BAPN) and angiotensin II (AngII) for 14 days. Rapamycin treatment was started either at day 1 or at day 7 of BAPN+AngII challenge, and continued throughout the observational period. Rapamycin was effective both in preventing AD development and in suppressing AD progression. On the other hand, gefitinib, an inhibitor of growth factor signaling, did not show such a beneficial effect, even though both rapamycin and gefitinib suppressed cell cycle activation in AD. Rapamycin suppressed cell cycle-related genes and induced muscle development-related genes in an AD-related gene expression network without a major impact on inflammation-related genes. Rapamycin augmented the activation of Akt1, Akt2, and Stat3, and maintained the contractile phenotype of aortic smooth muscle cells. These findings indicate that rapamycin was effective both in preventing the development and in suppressing the progression of AD, indicating the importance of the mTOR pathway in AD pathogenesis.

Aortic dissection (AD) is a major cause of acute aortic syndrome with high mortality due to the destruction of aortic walls. Although recent studies indicate the critical role of inflammation in the disease mechanism of AD, it is unclear how inflammatory response is initiated. Here, we demonstrate that myocardin-related transcription factor A (MRTF-A), a signal transducer of humoral and mechanical stress, plays an important role in pathogenesis of AD in a mouse model. A mouse model of AD was created by continuous infusion of angiotensin II (AngII) that induced MRTF-A expression and caused AD in 4 days. Systemic deletion of Mrtfa gene resulted in a marked suppression of AD development. Transcriptome and gene annotation enrichment analyses revealed that AngII infusion for 1 day caused pro-inflammatory and pro-apoptotic responses before AD development, which were suppressed by Mrtfa deletion. AngII infusion for 1 day induced pro-inflammatory response, as demonstrated by expressions of Il6, Tnf, and Ccl2, and apoptosis of aortic wall cells, as detected by TUNEL staining, in an MRTF-A-dependent manner. Pharmacological inhibition of MRTF-A by CCG-203971 during AngII infusion partially suppressed AD phenotype, indicating that acute suppression of MRTF-A is effective in preventing the aortic wall destruction. These results indicate that MRTF-A transduces the stress of AngII challenge to the pro-inflammatory and pro-apoptotic responses, ultimately leading to AD development. Intervening this pathway may represent a potential therapeutic strategy.

Background Abdominal aortic aneurysm ( AAA ) is a potentially life‐threatening disease that is common in older individuals. Currently, therapeutic options are limited to surgical interventions. Although it has long been known that AAA tissue is enriched in B cells and immunoglobulins, their involvement in AAA pathogenesis remains controversial. Methods and Results We investigated the role of B cells and immunoglobulins in a murine model of AAA , induced with a periaortic application of CaCl 2 , and in human AAA . Both human and mouse AAA tissue showed B‐cell infiltration. Mouse AAA tissue showed deposition of IgG and activation of Syk, a key molecule in B‐cell activation and immunoglobulin function, which were localized to infiltrating cells including B cells and macrophages. B‐cell–deficient mu MT mice showed suppression of AAA development that was associated with reduced activation of Syk and less expression of matrix metalloproteinase‐9. Administration of exogenous immunoglobulins restored the blunted Syk activation and AAA development in mu MT mice. Additionally, exogenous immunoglobulins induced interleukin‐6 and metalloproteinase‐9 secretions in human AAA tissue cultures. Furthermore, administration of R788, a specific Syk inhibitor, suppressed AAA expansion, reduced inflammatory response, and reduced immunoglobulin deposition in AAA tissue. Conclusions From these results, we concluded that B cells and immunoglobulins participated in AAA pathogenesis by promoting inflammatory and tissue‐destructive activities. Finally, we identified Syk as a potential therapeutic target.

Background Aortic dissection ( AD ) is a life‐threatening medical emergency caused by the abrupt destruction of the intimomedial layer of the aortic walls. Given that previous studies have reported the involvement of proinflammatory cytokine interleukin‐6 in AD pathogenesis, we investigated the role of signal transduction and activator of transcription 3 signaling, a downstream pathway of interleukin‐6 in macrophages in pathogenesis of AD . Methods and Results We characterized the pathological and molecular events triggered by aortic stress, which can lead to AD . Aortic stress on the suprarenal aorta because of infrarenal aorta stiffening and angiotensin II infusion for 1 week caused focal medial rupture at the branching point of the celiac trunk and superior mesenteric artery. This focal medial rupture healed in 6 weeks in wild‐type ( WT ) mice, but progressed to AD in mice with macrophage‐specific deletion of Socs3 gene ( mS ocs3‐ KO ). mS ocs3‐ KO mice showed premature activation of cell proliferation, an inflammatory response, and skewed differentiation of macrophages toward the tissue‐destructive phenotype. Concomitantly, they showed aberrant phenotypic modulation of smooth muscle cells and transforming growth factor beta signaling, which are likely to participate in tissue repair. Human AD samples revealed signal transduction and activator of transcription 3 activation in adventitial macrophages adjacent to the site of tissue destruction. Conclusions These findings suggest that AD development is preceded by focal medial rupture, in which macrophage Socs3 maintains proper inflammatory response and differentiation of SMC s, thus promoting fibrotic healing to prevent tissue destruction and AD development. Understanding the sequence of the pathological and molecular events preceding AD development will help predict and prevent AD development and progression.

Chronic inflammation underlies the pathological progression of various diseases, and thus many efforts have been made to quantitatively evaluate the inflammatory status of the diseases. In this study, we generated a highly sensitive inflammation-monitoring mouse system using a bacterial artificial chromosome (BAC) clone containing extended flanking sequences of the human interleukin 6 gene (hIL6) locus, in which the luciferase (Luc) reporter gene is integrated (hIL6-BAC-Luc). We successfully monitored lipopolysaccharide-induced systemic inflammation in various tissues of the hIL6-BAC-Luc mice using an in vivo bioluminescence imaging system. When two chronic inflammatory disease models, i.e., a genetic model of atopic dermatitis and a model of experimental autoimmune encephalomyelitis (EAE), were applied to the hIL6-BAC-Luc mice, luciferase bioluminescence was specifically detected in the atopic skin lesion and central nervous system, respectively. Moreover, the Luc activities correlated well with the disease severity. Nrf2 is a master transcription factor that regulates antioxidative and detoxification enzyme genes. Upon EAE induction, the Nrf2-deficient mice crossed with the hIL6-BAC-Luc mice exhibited enhanced neurological symptoms concomitantly with robust luciferase luminescence in the neuronal tissue. Thus, whole-body in vivo monitoring using the hIL6-BAC-Luc transgenic system (WIM-6 system) provides a new and powerful diagnostic tool for real-time in vivo monitoring of inflammatory status in multiple different disease models.

Sickle cell disease (SCD) is an inherited disorder caused by a point mutation in the β-globin gene, leading to the production of abnormally shaped red blood cells. Sickle cells are prone to hemolysis and thereby release free heme into plasma, causing oxidative stress and inflammation that in turn result in damage to multiple organs. The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is a master regulator of the antioxidant cell-defense system. Here we show that constitutive Nrf2 activation by ablation of its negative regulator Keap1 (kelch-like ECH-associated protein 1) significantly improves symptoms in SCD model mice. SCD mice exhibit severe liver damage and lung inflammation associated with high expression levels of proinflammatory cytokines and adhesion molecules compared with normal mice. Importantly, these symptoms subsided after Nrf2 activation. Although hemolysis and stress erythropoiesis did not change substantially in the Nrf2-activated SCD mice, Nrf2 promoted the elimination of plasma heme released by sickle cells' hemolysis and thereby reduced oxidative stress and inflammation, demonstrating that Nrf2 activation reduces organ damage and segregates inflammation from prevention of hemolysis in SCD mice. Furthermore, administration of the Nrf2 inducer CDDO-Im (2-cyano-3, 12 dioxooleana-1, 9 diene-28-imidazolide) also relieved inflammation and organ failure in SCD mice. These results support the contention that Nrf2 induction may be an important means to protect organs from the pathophysiology of sickle cell-induced damage.

Acute kidney injury (AKI) is a leading cause of chronic kidney disease. Proximal tubules are considered to be the primary origin of pathogenic inflammatory cytokines in AKI. However, it remains unclear whether other cell types, including collecting duct (CD) cells, participate in inflammatory processes. The transcription factor GATA2 is specifically expressed in CD cells and maintains their cellular identity. To explore the pathophysiological function of GATA2 in AKI, we generated renal tubular cell-specific Gata2 deletion (G2CKO) mice and examined their susceptibility to ischemia reperfusion injury (IRI). Notably, G2CKO mice exhibited less severe kidney damage, with reduced granulomacrophagic infiltration upon IRI. Transcriptome analysis revealed that a series of inflammatory cytokine genes were downregulated in GATA2-deficient CD cells, suggesting that GATA2 induces inflammatory cytokine expression in diseased kidney CD cells. Through high-throughput chemical library screening, we identified a potent GATA inhibitor. The chemical reduces cytokine production in CD cells and protects the mouse kidney from IRI. These results revealed a novel pathological mechanism of renal IRI, namely, that CD cells produce inflammatory cytokines and promote IRI progression. In injured kidney CD cells, GATA2 exerts a proinflammatory function by upregulating inflammatory cytokine gene expression. GATA2 can therefore be considered a therapeutic target for AKI.

Although the pathogenesis of abdominal aortic aneurysm (AAA) remains unclear, evidence is accumulating to support a central role for inflammation. Inflammatory responses are coordinated by various soluble cytokines of which IL-6 is one of the major proinflammatory cytokines. In this study we examined the role of IL-6 in the pathogenesis of experimental AAA induced by a periaortic exposure to CaCl2 in mice. We now report that the administration of MR16-1, a neutralizing monoclonal antibody specific for the mouse IL-6 receptor, mildly suppressed the development of AAA. The inhibition of IL-6 signaling provoked by MR16-1 also resulted in a suppression of Stat3 activity. Conversely, no significant changes in either NFκB activity, Jnk activity or the expression of matrix metalloproteinases (Mmp) -2 and -9 were identified. Transcriptome analyses revealed that MR16-1-sensitive genes encode chemokines and their receptors, as well as factors that regulate vascular permeability and cell migration. Imaging cytometric analyses then consistently demonstrated reduced cellular infiltration for MR16-1-treated AAA. These results suggest that IL-6 plays an important but limited role in AAA pathogenesis, and primarily regulates cell migration and infiltration. These data would also suggest that IL-6 activity may play an important role in scenarios of continuous cellular infiltration, possibly including human AAA.

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy characterized by clinical and genetic heterogeneity. Although more than 30 loci harboring CMT-causing mutations have been identified, many other genes still remain to be discovered for many affected individuals. For two consanguineous families with CMT (axonal and mixed phenotypes), a parametric linkage analysis using genome-wide SNP chip identified a 4.3 Mb region on 12q24 showing a maximum multipoint LOD score of 4.23. Subsequent whole-genome sequencing study in one of the probands, followed by mutation screening in the two families, revealed a disease-specific 5 bp deletion (c.247−10_247−6delCACTC) in a splicing element (pyrimidine tract) of intron 2 adjacent to the third exon of cytochrome c oxidase subunit VIa polypeptide 1 (COX6A1), which is a component of mitochondrial respiratory complex IV (cytochrome c oxidase [COX]), within the autozygous linkage region. Functional analysis showed that expression of COX6A1 in peripheral white blood cells from the affected individuals and COX activity in their EB-virus-transformed lymphoblastoid cell lines were significantly reduced. In addition, Cox6a1-null mice showed significantly reduced COX activity and neurogenic muscular atrophy leading to a difficulty in walking. Those data indicated that COX6A1 mutation causes the autosomal-recessive axonal or mixed CMT.