Research Article
Abstract
Liver metastasis represents one of the most frequent malignant diseases with no effective treatment. Functional reprogramming of Kupffer cells (KCs), the largest population of hepatic macrophages, holds promise for treating liver cancer, but remains seldom exploited. Taking advantage of the superior capacity of KCs to capture circulating bacteria, we report that a single administration of attenuated Escherichia coli producing clustered regularly interspersed short palindromic repeats CasΦ (CRISPR/CasΦ) machinery enables efficient editing of genes of interest in KCs. Using intravital microscopy, we observed a failure of tumor control by KCs at the late stage of liver metastasis due to KC loss preferentially in the tumor core and periphery, resulting in inaccessibility of these highly phagocytic macrophages to cancer cells. Simultaneous disruption of MafB and c-Maf expression using the aforementioned engineered bacteria could overcome KC dysfunction and elicit remarkable curative effects against several types of metastatic liver cancer in mice. Mechanistically, bacterial treatment induced massive proliferation and functional reprogramming of KCs. These cells infiltrated into the tumor, dismantled macrometastases by nibbling cancer cells, and skewed toward proinflammatory macrophages to unleash antitumor T cell responses. These findings provide an immunotherapy strategy that could be applicable for treating liver metastasis and highlight the therapeutic potential of targeting tissue-resident macrophages in cancer.
Authors
Wei Liu, Xia Zhou, Qi Yao, Chen Chen, Qing Zhang, Keshuo Ding, Lu Li, Zhutian Zeng
Abstract
The spatiotemporal pattern of the spread of pathologically modified tau through brain regions in Alzheimer’s disease (AD) can be explained by prion-like cell-to-cell seeding and propagation of misfolded tau aggregates. Hence, to develop targeted therapeutic antibodies, it is important to identify the seeding- and propagation-competent tau species. The hexapeptide 275VQIINK280 of tau is a critical region for tau aggregation, and K280 is acetylated in various tauopathies, including AD. However, the mechanism that links tau acetylated on lysine 280 (tau-acK280) to subsequent progression to neurodegenerative disease remains unclear. Here, we demonstrate that tau-acK280 is critical for tau propagation processes including secretion, aggregation, and seeding. We developed an antibody, Y01, that specifically targets tau-acK280 and solved the crystal structure of Y01 in complex with an acK280 peptide. The structure confirmed that Y01 directly recognizes acK280 and the surrounding residues. Strikingly, upon interaction with acetylated tau aggregates, Y01 prevented tauopathy progression and increased neuronal viability in neuron cultures and in tau-Tg mice through antibody-mediated neutralization and phagocytosis, respectively. Based on our observations that tau-acK280 is a core species involved in seeding and propagation activities, the Y01 antibody that specifically recognizes acK280 represents a promising therapeutic candidate for AD and other neurodegenerative diseases associated with tauopathy.
Authors
Ha-Lim Song, Na-Young Kim, Jaewan Park, Meong Il Kim, Yu-Na Jeon, Se-Jong Lee, Kwangmin Cho, Young-Lim Shim, Kyoung-Hye Lee, Yeon-Seon Mun, Jung-A Song, Min-Seok Kim, Chan-Gi Pack, Minkyo Jung, Hyemin Jang, Duk L. Na, Minsun Hong, Dong-Hou Kim, Seung-Yong Yoon
Abstract
Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.
Authors
Nafisa Nuzhat, Kristof Van Schil, Sandra Liakopoulos, Miriam Bauwens, Alfredo Dueñas Rey, Stephan Käseberg, Melanie Jäger, Jason R. Willer, Jennifer Winter, Hanh M. Truong, Nuria Gruartmoner, Mattias Van Heetvelde, Joachim Wolf, Robert Merget, Sabine Grasshoff-Derr, Jo Van Dorpe, Anne Hoorens, Heidi Stöhr, Luke Mansard, Anne-Françoise Roux, Thomas Langmann, Katharina Dannhausen, David Rosenkranz, Karl M. Wissing, Michel Van Lint, Heidi Rossmann, Friederike Häuser, Peter Nürnberg, Holger Thiele, Ulrich Zechner, Jillian N. Pearring, Elfride De Baere, Hanno J. Bolz
Abstract
Genetic defects of GNAS, the imprinted gene encoding the stimulatory G protein α-subunit, are responsible for multiple diseases. Abnormal GNAS imprinting causes pseudohypoparathyroidism type 1B (PHP1B), a prototype of mammalian end-organ hormone resistance. Hypomethylation at the maternally methylated GNAS A/B region is the only shared defect in patients with PHP1B. In autosomal dominant (AD) PHP1B kindreds, A/B hypomethylation is associated with maternal microdeletions at either the GNAS NESP55 differentially methylated region or the STX16 gene located approximately 170 kb upstream. Functional evidence is meager regarding the causality of these microdeletions. Moreover, the mechanisms linking A/B methylation and the putative imprinting control regions (ICRs) NESP-ICR and STX16-ICR remain unknown. Here, we generated a human embryonic stem cell model of AD-PHP1B by introducing ICR deletions using CRISPR/Cas9. With this model, we showed that the NESP-ICR is required for methylation and transcriptional silencing of A/B on the maternal allele. We also found that the SXT16-ICR is a long-range enhancer of NESP55 transcription, which originates from the maternal NESP-ICR. Furthermore, we demonstrated that the STX16-ICR is an embryonic stage–specific enhancer enabled by the direct binding of pluripotency factors. Our findings uncover an essential GNAS imprinting control mechanism and advance the molecular understanding of PHP1B pathogenesis.
Authors
Yorihiro Iwasaki, Cagri Aksu, Monica Reyes, Birol Ay, Qing He, Murat Bastepe
Abstract
IL-17A (IL-17), a driver of the inflammatory phase of fracture repair, is produced locally by several cell lineages including γδ T cells and Th17 cells. However, the origin of these T cells and their relevance for fracture repair are unknown. Here, we show that fractures rapidly expanded callus γδ T cells, which led to increased gut permeability by promoting systemic inflammation. When the microbiota contained the Th17 cell–inducing taxon segmented filamentous bacteria (SFB), activation of γδ T cells was followed by expansion of intestinal Th17 cells, their migration to the callus, and improved fracture repair. Mechanistically, fractures increased the S1P receptor 1–mediated (S1PR1-mediated) egress of Th17 cells from the intestine and enhanced their homing to the callus through a CCL20-mediated mechanism. Fracture repair was impaired by deletion of γδ T cells, depletion of the microbiome by antibiotics (Abx), blockade of Th17 cell egress from the gut, or Ab neutralization of Th17 cell influx into the callus. These findings demonstrate the relevance of the microbiome and T cell trafficking for fracture repair. Modifications of microbiome composition via Th17 cell–inducing bacteriotherapy and avoidance of broad-spectrum Abx may represent novel therapeutic strategies to optimize fracture healing.
Authors
Hamid Y. Dar, Daniel S. Perrien, Subhashis Pal, Andreea Stoica, Sasidhar Uppuganti, Jeffry S. Nyman, Rheinallt M. Jones, M. Neale Weitzmann, Roberto Pacifici
Abstract
Rhythmic intraorgan communication coordinates environmental signals and the cell-intrinsic clock to maintain organ homeostasis. Hepatocyte-specific KO of core components of the molecular clock Rev-erbα and -β (Reverb-hDKO) alters cholesterol and lipid metabolism in hepatocytes as well as rhythmic gene expression in nonparenchymal cells (NPCs) of the liver. Here, we report that in fatty liver caused by diet-induced obesity (DIO), hepatocyte SREBP cleavage–activating protein (SCAP) was required for Reverb-hDKO–induced diurnal rhythmic remodeling and epigenomic reprogramming in liver macrophages (LMs). Integrative analyses of isolated hepatocytes and LMs revealed that SCAP-dependent lipidomic changes in REV-ERB–depleted hepatocytes led to the enhancement of LM metabolic rhythms. Hepatocytic loss of REV-ERBα and β (REV-ERBs) also attenuated LM rhythms via SCAP-independent polypeptide secretion. These results shed light on the signaling mechanisms by which hepatocytes regulate diurnal rhythms in NPCs in fatty liver disease caused by DIO.
Authors
Dongyin Guan, Hosung Bae, Dishu Zhou, Ying Chen, Chunjie Jiang, Cam Mong La, Yang Xiao, Kun Zhu, Wenxiang Hu, Trang Minh Trinh, Panpan Liu, Ying Xiong, Bishuang Cai, Cholsoon Jang, Mitchell A. Lazar
Abstract
Ferritin, a key regulator of iron homeostasis in macrophages, has been reported to confer host defenses against Mycobacterium tuberculosis (Mtb) infection. Nuclear receptor coactivator 4 (NCOA4) was recently identified as a cargo receptor in ferritin degradation. Here, we show that Mtb infection enhanced NCOA4-mediated ferritin degradation in macrophages, which in turn increased the bioavailability of iron to intracellular Mtb and therefore promoted bacterial growth. Of clinical relevance, the upregulation of FTH1 in macrophages was associated with tuberculosis (TB) disease progression in humans. Mechanistically, Mtb infection enhanced NCOA4-mediated ferritin degradation through p38/AKT1- and TRIM21-mediated proteasomal degradation of HERC2, an E3 ligase of NCOA4. Finally, we confirmed that NCOA4 deficiency in myeloid cells expedites the clearance of Mtb infection in a murine model. Together, our findings revealed a strategy by which Mtb hijacks host ferritin metabolism for its own intracellular survival. Therefore, this represents a potential target for host-directed therapy against tuberculosis.
Authors
Youchao Dai, Chuanzhi Zhu, Wei Xiao, Kaisong Huang, Xin Wang, Chenyan Shi, Dachuan Lin, Huihua Zhang, Xiaoqian Liu, Bin Peng, Yi Gao, Cui Hua Liu, Baoxue Ge, Stefan H.E. Kaufmann, Carl G. Feng, Xinchun Chen, Yi Cai
Abstract
Sepsis pathogenesis is complex and heterogeneous; hence, a precision-medicine strategy is needed. Acute kidney injury (AKI) following sepsis portends higher mortality. Overproduction of mitochondrial ROS (mtROS) is a potential mediator of sepsis and sepsis-induced AKI. BAM15, a chemical uncoupler, dissipates mitochondrial proton gradients without generating mtROS. We injected BAM15 into mice at 0, 6, or 12 hours after cecal ligation and puncture (CLP), and these mice were treated with fluids and antibiotics. BAM15 reduced mortality, even after 12 hours, when mice were ill, and BAM15 reduced kidney damage and splenic apoptosis. Serial plasma and urinary mitochondrial DNA (mtDNA) levels increased after CLP and decreased after BAM15 administration (at 0 or 6 hours). In vitro septic serum proportionately increased mtROS overproduction and mtDNA release from kidney tubule cells, which BAM15 prevented. BAM15 decreased neutrophil apoptosis and mtDNA release; neutrophil depletion counteracted BAM15 benefits. Further, mtDNA injection in vivo replicated inflammation and kidney injury, which was prevented by BAM15. A large dose of exogenous mtDNA reversed protection by BAM15. We conclude that BAM15 is an effective preventive and therapeutic candidate in experimental sepsis and that BAM15 and mtDNA, a potential drug-companion diagnostic/drug-efficacy pair for clinical sepsis, are mechanistically linked via mtROS.
Authors
Naoko Tsuji, Takayuki Tsuji, Tetsushi Yamashita, Naoki Hayase, Xuzhen Hu, Peter S.T. Yuen, Robert A. Star
Abstract
Multiple sclerosis (MS) is a progressive inflammatory demyelinating disease of the CNS. Increasing evidence suggests that vulnerable neurons in MS exhibit fatal metabolic exhaustion over time, a phenomenon hypothesized to be caused by chronic hyperexcitability. Axonal Kv7 (outward-rectifying) and oligodendroglial Kir4.1 (inward-rectifying) potassium channels have important roles in regulating neuronal excitability at and around the nodes of Ranvier. Here, we studied the spatial and functional relationship between neuronal Kv7 and oligodendroglial Kir4.1 channels and assessed the transcriptional and functional signatures of cortical and retinal projection neurons under physiological and inflammatory demyelinating conditions. We found that both channels became dysregulated in MS and experimental autoimmune encephalomyelitis (EAE), with Kir4.1 channels being chronically downregulated and Kv7 channel subunits being transiently upregulated during inflammatory demyelination. Further, we observed that pharmacological Kv7 channel opening with retigabine reduced neuronal hyperexcitability in human and EAE neurons, improved clinical EAE signs, and rescued neuronal pathology in oligodendrocyte–Kir4.1–deficient (OL-Kir4.1–deficient) mice. In summary, our findings indicate that neuron-OL compensatory interactions promoted resilience through Kv7 and Kir4.1 channels and identify pharmacological activation of nodal Kv7 channels as a neuroprotective strategy against inflammatory demyelination.
Authors
Hannah Kapell, Luca Fazio, Julia Dyckow, Sophia Schwarz, Andrés Cruz-Herranz, Christina Mayer, Joaquin Campos, Elisa D’Este, Wiebke Möbius, Christian Cordano, Anne-Katrin Pröbstel, Marjan Gharagozloo, Amel Zulji, Venu Narayanan Naik, Anna Delank, Manuela Cerina, Thomas Müntefering, Celia Lerma-Martin, Jana K. Sonner, Jung Hyung Sin, Paul Disse, Nicole Rychlik, Khalida Sabeur, Manideep Chavali, Rajneesh Srivastava, Matthias Heidenreich, Kathryn C. Fitzgerald, Guiscard Seebohm, Christine Stadelmann, Bernhard Hemmer, Michael Platten, Thomas J. Jentsch, Maren Engelhardt, Thomas Budde, Klaus-Armin Nave, Peter A. Calabresi, Manuel A. Friese, Ari J. Green, Claudio Acuna, David H. Rowitch, Sven G. Meuth, Lucas Schirmer
Abstract
Although protein hydroxylation is a relatively poorly characterized posttranslational modification, it has received significant recent attention following seminal work uncovering its role in oxygen sensing and hypoxia biology. Although the fundamental importance of protein hydroxylases in biology is becoming clear, the biochemical targets and cellular functions often remain enigmatic. JMJD5 is a “JmjC-only” protein hydroxylase that is essential for murine embryonic development and viability. However, no germline variants in JmjC-only hydroxylases, including JMJD5, have yet been described that are associated with any human pathology. Here we demonstrate that biallelic germline JMJD5 pathogenic variants are deleterious to JMJD5 mRNA splicing, protein stability, and hydroxylase activity, resulting in a human developmental disorder characterized by severe failure to thrive, intellectual disability, and facial dysmorphism. We show that the underlying cellular phenotype is associated with increased DNA replication stress and that this is critically dependent on the protein hydroxylase activity of JMJD5. This work contributes to our growing understanding of the role and importance of protein hydroxylases in human development and disease.
Authors
Sally C. Fletcher, Charlotte Hall, Tristan J. Kennedy, Sander Pajusalu, Monica H. Wojcik, Uncaar Boora, Chan Li, Kaisa Teele Oja, Eline Hendrix, Christian A.E. Westrip, Regina Andrijes, Sonia K. Piasecka, Mansi Singh, Mohammed E. El-Asrag, Anetta Ptasinska, Vallo Tillmann, Martin R. Higgs, Deanna A. Carere, Andrew D. Beggs, John Pappas, Rachel Rabin, Stephen J. Smerdon, Grant S. Stewart, Katrin Õunap, Mathew L. Coleman
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ISSN: 0021-9738 (print), 1558-8238 (online)