Publications

Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia

T-cell acute lymphoblastic leukaemia (T-ALL) is a haematological malignancy with a poor prognosis and no available targeted therapies; now two histone H3 lysine 27 demethylases, JMJD3 and UTX, are shown to have contrasting roles in human T-ALL cells and a mouse model of the disease, and a small molecule demethylase inhibitor is found to inhibit the growth of T-ALL cell lines, introducing a potential therapeutic avenue for acute leukaemia. Two histone H3 lysine 27 demethylases, JMJD3 and UTX, are shown here to have contrasting roles in human T-cell acute lymphoblastic leukaemia (T-ALL) cells and a mouse model of the disease. JMJD3 is overexpressed in T-ALL and essential for initiation and maintenance of disease, whereas UTX is a target of inactivating mutations in human T-ALL and acts a tumour suppressor. A small-molecule demethylase inhibitor inhibits the growth of T-ALL cell lines, introducing a potential therapeutic avenue for an acute leukemia that has a poor prognosis and no currently available targeted therapies. T-cell acute lymphoblastic leukaemia (T-ALL) is a haematological malignancy with a dismal overall prognosis, including a relapse rate of up to 25%, mainly because of the lack of non-cytotoxic targeted therapy options. Drugs that target the function of key epigenetic factors have been approved in the context of haematopoietic disorders1, and mutations that affect chromatin modulators in a variety of leukaemias have recently been identified2,3; however, ‘epigenetic’ drugs are not currently used for T-ALL treatment. Recently, we described that the polycomb repressive complex 2 (PRC2) has a tumour-suppressor role in T-ALL4. Here we delineated the role of the histone 3 lysine 27 (H3K27) demethylases JMJD3 and UTX in T-ALL. We show that JMJD3 is essential for the initiation and maintenance of T-ALL, as it controls important oncogenic gene targets by modulating H3K27 methylation. By contrast, we found that UTX functions as a tumour suppressor and is frequently genetically inactivated in T-ALL. Moreover, we demonstrated that the small molecule inhibitor GSKJ4 (ref. 5) affects T-ALL growth, by targeting JMJD3 activity. These findings show that two proteins with a similar enzymatic function can have opposing roles in the context of the same disease, paving the way for treating haematopoietic malignancies with a new category of epigenetic inhibitors.

The kinase domain of death-associated protein kinase is inhibitory for tubulointerstitial fibrosis in chronic obstructive nephropathy

Death-associated protein kinase (DAPK) is a Ca2+/calmodulin-dependent serine/threonine kinase that is thought to mediate apoptosis. We have shown that the kinase domain of DAPK is crucial for the induction of renal tubular cell apoptosis in chronic obstructive uropathy (COU) created by unilateral ureteral ligation. DAPK-mutant mice, generated by deletion of 74 amino acids from the catalytic kinase domain, were used to investigate the role of the DAPK kinase domain in renal fibrosis following COU. Interstitial collagen and alpha-smooth muscle actin (alpha-SMA) expressions in situ were compared between obstructed kidneys in wild-type and mutant mice. As a result, tubulointerstitial fibrosis, as quantified by interstitial collagen expression, was significantly augmented in mutant kidneys compared with wild-type kidneys following COU. Furthermore, deletion of the kinase domain from DAPK significantly increased the appearance of alpha-SMA-positive myofibroblasts in the renal interstitium during COU. Thus, our results suggest that the kinase domain deleted by gene targeting plays a suppressive role for the development of renal fibrosis through inhibition of the tubular epithelial-to-mesenchymal transition in a mouse model of COU.

Role of MyD88 and Toll-Like Receptors 2 and 4 in the Sensing of<i>Parachlamydia acanthamoebae</i>

Parachlamydia acanthamoebae is a Chlamydia-related organism whose pathogenic role in pneumonia is supported by serological and molecular clinical studies and an experimental mouse model of lung infection. Toll-like receptors (TLRs) play a seminal role in sensing microbial products and initiating innate immune responses. The aim of this study was to investigate the roles of MyD88, TLR2, and TLR4 in the interaction of Parachlamydia with macrophages. Here, we showed that Parachlamydia entered bone-marrow derived macrophages (BMDMs) in a TLR-independent manner but did not multiply intracellularly. Interestingly, compared to live bacteria, heat-inactivated Parachlamydia induced the production of substantial amounts of tumor necrosis factor alpha (TNF), interleukin-6 (IL-6), and IL-12p40 by BMDMs and of TNF and IL-6 by peritoneal macrophages as well as RAW 264.7 and J774 macrophage cell lines. Cytokine production by BMDMs, which was partially inhibited upon trypsin treatment of Parachlamydia, was dependent on MyD88, TLR4, and, to a lesser extent, TLR2. Finally, MyD88(-/-), TLR4(-/-), and TLR2(-/-) mice were as resistant as wild-type mice to lung infection following the intratracheal instillation of Parachlamydia. Thus, in contrast to Chlamydia pneumoniae, Parachlamydia acanthamoebae weakly stimulates macrophages, potentially compensating for its low replication capacity in macrophages by escaping the innate immune surveillance.

Class-switching from mu to gamma 3 or gamma 2b production at pre-B cell stage.

An Abelson virus-transformed murine pre-B cell line class-switched from mu to gamma 3 or gamma 2b at the pre-B stage during culture. A class-switch was mediated by the deletion mechanism of the intervening CH genes on the active chromosome. This study showed for the first time that class-switching at the pre-B cell stage was not always confined to gamma 2b production.

recognizes bacterial DNA

No abstract is provided for this article.

Faculty Opinions recommendation of Caspase-12 controls West Nile virus infection via the viral RNA receptor RIG-I.

Pathogenic role of B cells in the development of diffuse alveolar hemorrhage induced by pristane

Diffuse alveolar hemorrhage is an uncommon, yet often fatal, complication of systemic lupus erythematosus (SLE). Advances in the treatment of alveolar hemorrhage have been hampered because of the heterogeneity of clinical findings and the lack of suitable animal models. A single intraperitoneal injection of pristane induces a lupus-like syndrome characterized by lupus-related autoantibodies and glomerulonephritis in non-autoimmune-prone strains of mice. In addition, C57BL/6 (B6) mice frequently develop alveolar hemorrhage within a few weeks of pristane injection. Immunopathogenesis of pristane-induced alveolar hemorrhage was investigated in the present study. Early (2–4 weeks after injection) mortality due to hemorrhage was unique to C57BL/6 and C57BL/10 strains of mice. Recruitment of the macrophages and neutrophils preceded the hemorrhage by several days, and hemorrhage started 3–7 days after pristane injection in some mice, peaked at 2 weeks (84% in B6) and then resolved by 4 weeks in a majority of mice. Alveolar hemorrhage was independent of MyD88 (myeloid differentiation factor 88), or TLR7 pathways, in contrast to autoantibody production and glomerulonephritis, and was also independent of FcγR or Fas. Rag1−/− mice had a reduced prevalence of alveolar hemorrhage compared with B6 (P=0.01) congenics. However, T-cell receptor-deficient mice developed alveolar hemorrhage at a rate comparable to wild-type controls, whereas B6 Igμ −/− mice surprisingly had a strikingly reduced prevalence (7% vs 84% in B6, P<0.0001). Reconstitution of B6 Igμ −/− mice with wild-type B cells increased the prevalence to 50% (P=0.028). Pristane-induced alveolar hemorrhage is a useful model to study the pathogenesis and develop new therapy for this underappreciated and often life-threatening complication of SLE.

Hematopoietic IKBKE limits the chronicity of inflammasome priming and metaflammation

Obesity increases the risk of developing life-threatening metabolic diseases including cardiovascular disease, fatty liver disease, diabetes, and cancer. Efforts to curb the global obesity epidemic and its impact have proven unsuccessful in part by a limited understanding of these chronic progressive diseases. It is clear that low-grade chronic inflammation, or metaflammation, underlies the pathogenesis of obesity-associated type 2 diabetes and atherosclerosis. However, the mechanisms that maintain chronicity and prevent inflammatory resolution are poorly understood. Here, we show that inhibitor of κB kinase epsilon (IKBKE) is a novel regulator that limits chronic inflammation during metabolic disease and atherosclerosis. The pathogenic relevance of IKBKE was indicated by the colocalization with macrophages in human and murine tissues and in atherosclerotic plaques. Genetic ablation of IKBKE resulted in enhanced and prolonged priming of the NLRP3 inflammasome in cultured macrophages, in hypertrophic adipose tissue, and in livers of hypercholesterolemic mice. This altered profile associated with enhanced acute phase response, deregulated cholesterol metabolism, and steatoheptatitis. Restoring IKBKE only in hematopoietic cells was sufficient to reverse elevated inflammasome priming and these metabolic features. In advanced atherosclerotic plaques, loss of IKBKE and hematopoietic cell restoration altered plaque composition. These studies reveal a new role for hematopoietic IKBKE: to limit inflammasome priming and metaflammation.

Two Beclin 1-binding proteins, Atg14L and Rubicon, reciprocally regulate autophagy at different stages

No abstract is provided for this article.

RAE1 Ligands for the NKG2D Receptor Are Regulated by STING-Dependent DNA Sensor Pathways in Lymphoma

The immunoreceptor NKG2D originally identified in natural killer (NK) cells recognizes ligands that are upregulated on tumor cells. Expression of NKG2D ligands (NKG2DL) is induced by the DNA damage response (DDR), which is often activated constitutively in cancer cells, revealing them to NK cells as a mechanism of immunosurveillance. Here, we report that the induction of retinoic acid early transcript 1 (RAE1) ligands for NKG2D by the DDR relies on a STING-dependent DNA sensor pathway involving the effector molecules TBK1 and IRF3. Cytosolic DNA was detected in lymphoma cell lines that express RAE1 and its occurrence required activation of the DDR. Transfection of DNA into ligand-negative cells was sufficient to induce RAE1 expression. Irf3(+/-);Eμ-Myc mice expressed lower levels of RAE1 on tumor cells and showed a reduced survival rate compared with Irf3(+/+);Eμ-Myc mice. Taken together, our results suggest that genomic damage in tumor cells leads to activation of STING-dependent DNA sensor pathways, thereby activating RAE1 and enabling tumor immunosurveillance.

Toll-like receptor 9 controls anti-DNA autoantibody production in murine lupus

Systemic autoimmune disease in humans and mice is characterized by loss of immunologic tolerance to a restricted set of self-nuclear antigens. Autoantigens, such as double-stranded (ds) DNA and the RNA-containing Smith antigen (Sm), may be selectively targeted in systemic lupus erythematosus because of their ability to activate a putative common receptor. Toll-like receptor 9 (TLR9), a receptor for CpG DNA, has been implicated in the activation of autoreactive B cells in vitro, but its role in promoting autoantibody production and disease in vivo has not been determined. We show that in TLR9-deficient lupus-prone mice, the generation of anti-dsDNA and antichromatin autoantibodies is specifically inhibited. Other autoantibodies, such as anti-Sm, are maintained and even increased in TLR9-deficient mice. In contrast, ablation of TLR3, a receptor for dsRNA, did not inhibit the formation of autoantibodies to either RNA- or DNA-containing antigens. Surprisingly, we found that despite the lack of anti-dsDNA autoantibodies in TLR9-deficient mice, there was no effect on the development of clinical autoimmune disease or nephritis. These results demonstrate a specific requirement for TLR9 in autoantibody formation in vivo and indicate a critical role for innate immune activation in autoimmunity.

TLR13 Recognizes Bacterial 23 <i>S</i> rRNA Devoid of Erythromycin Resistance–Forming Modification

A Double Escapee Toll-like receptors (TLRs)—TLR2 and TLR7—are thought to contribute to the sensing of Gram-positive bacteria like Staphylococcus aureus and Streptococcus pneumoniae by the immune system. Mice deficient in these receptors, however, are still sensitive to infection with these bacteria. Oldenburg et al. (p. 1111 , published online 19 July) demonstrate that TLR13 also plays a role in detecting Gram-positive bacteria. TLR13 recognized a conserved region in the peptidyl transferase loop of bacterial 23S ribosomal RNA. Intriguingly, this same sequence is modified by specific methyltransferases that confer resistance to erythromycin. Indeed, erythromycin-resistant bacteria were no longer detectible by TLR13.

Release and innate detection of host cell DNA mediates the adjuvant effects of aluminum salts

No abstract is provided for this article.

USP15はウイルスRNA翻訳と脂質滴形成の調節を介してC型肝炎ウイルス伝播に関与する【JST・京大機械翻訳】

No abstract is provided for this article.

SPATIAL TRANSCRIPTOMICS IDENTIFIES SPARC AS A PROGNOSTIC BIOMARKER IN UNCLASSIFIABLE INTERSTITIAL LUNG DISEASES

Regulation of dsDNA-induced innate immune responses by membrane trafficking

Microbial nucleic acids are potent inducers of innate immune responses; the first line of host defense against microbes. It is known that double-stranded (ds) DNA triggers the expression of type I interferons (IFNs) and IFN-inducible genes resulting in the establishment of an antimicrobial environment. However, the regulatory mechanisms underlying the signaling pathways responsible for the induction of innate immune responses by dsDNA are still not fully understood. Recently, we showed that the translocation and subsequent assembly of the multi-spanning membrane protein, stimulator of interferon genes (STING), is critical for dsDNA-triggered innate immune responses. Following stimulation by dsDNA, STING translocates from the endoplasmic reticulum (ER) to the Golgi apparatus where it associates with TANK-binding kinase 1 (TBK1) on cytoplasmic punctate structures to induce the interferon regulatory factor 3 (IRF3)-dependent transcription of type I IFNs and IFN-inducible genes. We have also shown that dsDNA stimulation induces the colocalization of STING with the autophagy-related proteins Atg9a and microtubule-associated protein 1 light chain 3 (LC3). The targeted disruption of Atg9a, a multi-spanning membrane protein essential for autophagy, greatly promotes the dsDNA-driven assembly of STING and TBK1 leading to the aberrant activation of the innate immune response. However, the loss of Atg7, another essential component for autophagosome formation, does not affect the dsDNA-stimulated translocation of STING. Hence, Atg9a is a regulator of STING-mediated innate immune response as well as an essential autophagy protein. These findings indicate that dynamic membrane trafficking is triggered by dsDNA stimulation and plays a pivotal role in the signal transduction required for optimal activation of the innate immune response.This article refers to:

BATF2 activates DUSP2 gene expression and up-regulates NF-κB activity via phospho-STAT3 dephosphorylation

Growing evidence has revealed that the transcription factor basic leucine zipper transcription factor ATF-like 2 (BATF2) has unique transcriptional activities, including regulating cytokines via TLR signals in macrophages, which affect mortality due to infection and cancer. On the basis of genome-wide analyses using the chromatin immunoprecipitation-sequencing technique, we found that dual-specificity phosphatase 2 (Dusp2) had a significantly lower acetyl-histone status in Batf2−/− bone marrow-derived macrophages (BMDMs) compared with wild-type (WT) BMDMs. The phosphatase DUSP2 has been reported to play a critical role in inflammatory responses. Therefore, we evaluated the BATF2 transcriptional activities on the Dusp2 promoter. We found that the DUSP2 and IL-12 p40 expression levels were significantly lower in Batf2−/− BMDMs than in WT controls following their stimulation with TLR7 ligands. Further in vitro studies revealed that phospho-STAT3 was up-regulated and NF-κB p50/p65 were down-regulated in Batf2−/− BMDMs compared with their levels in WT controls. Additionally, Th1 immunity was impaired in Batf2−/− mice following their stimulation with TLR7 ligands. We also found that BATF2 interacts with NF-κB p65 and promotes DUSP2 expression through the NF-κB-binding site in the Dusp2 promoter at −203 to −121. Collectively, our findings suggest that BATF2 activates DUSP2 gene expression and up-regulates NF-κB activity via phospho-STAT3 dephosphorylation.

KLB is associated with alcohol drinking, and its gene product beta-Klotho is necessary for FGF21 regulation of alcohol preference

No abstract is provided for this article.