Rakova et al. and Kitada et al. report that glucocorticoid-driven responses to changes in salt alter sodium and water handling and metabolism in mice and in cosmonauts participating in long-term space-flight simulations. The cover shows an image of autophagy in murine skeletal muscle overlaid on an outer space–inspired background. Image credit: Dominic Doyle.
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Despite the prevalence of viral infections in the American population, we still have a limited understanding of how they affect pregnancy and fetal development. Viruses can gain access to the decidua and placenta by ascending from the lower reproductive tract or via hematogenous transmission. Viral tropism for the decidua and placenta is then dependent on viral entry receptor expression in these tissues as well as on the maternal immune response to the virus. These factors vary by cell type and gestational age and can be affected by changes to the in utero environment and maternal immunity. Some viruses can directly infect the fetus at specific times during gestation, while some only infect the placenta. Both scenarios can result in severe birth defects or pregnancy loss. Systemic maternal viral infections can also affect the pregnancy, and these can be especially dangerous, because pregnant women suffer higher virus-associated morbidity and mortality than do nonpregnant counterparts. In this Review, we discuss the potential contributions of maternal, placental, and fetal viral infection to pregnancy outcome, fetal development, and maternal well-being.
Karen Racicot, Gil Mor
The cardiac extracellular matrix (ECM) not only provides mechanical support, but also transduces essential molecular signals in health and disease. Following myocardial infarction, dynamic ECM changes drive inflammation and repair. Early generation of bioactive matrix fragments activates proinflammatory signaling. The formation of a highly plastic provisional matrix facilitates leukocyte infiltration and activates infarct myofibroblasts. Deposition of matricellular proteins modulates growth factor signaling and contributes to the spatial and temporal regulation of the reparative response. Mechanical stress due to pressure and volume overload and metabolic dysfunction also induce profound changes in ECM composition that contribute to the pathogenesis of heart failure. This manuscript reviews the role of the ECM in cardiac repair and remodeling and discusses matrix-based therapies that may attenuate remodeling while promoting repair and regeneration.
Nikolaos G. Frangogiannis
In the mid-1990s, my research group began to devise a method to establish endothelial cell cultures from human peripheral blood, with an ultimate goal of examining interindividual heterogeneity of endothelial biology. The initial work, published in the
Robert P. Hebbel
Patients who present with unique immunological phenotypes provide an opportunity to better understand defect-driving mutations. In this issue of the
It is increasingly evident that there is a genetic contribution to autism spectrum disorders (ASDs) and other neural disorders involving excessive repetition of action sequences. Among the implicated genes in these disorders are those encoding postsynaptic scaffolding proteins with roles in synaptic transmission and plasticity. Several mouse models harboring synonymous mutations have shown alterations in synaptic transmission within the striatum, which has key roles in controlling actions and action sequences. In this issue of the
David M. Lovinger
In this issue of the
It has long been viewed that the maintenance of osmotic balance in response to high salt intake is a passive process that is mediated largely by increased water consumption to balance the salt load. Two studies in this issue of the
Mark L. Zeidel
Allogeneic hematopoietic cell transplantation (HCT) represents a potentially curative treatment for a variety of hematologic malignancies due to the well-recognized graft-versus-leukemia/lymphoma (GVL) effect that is mediated by donor-derived alloreactive T cells. However, graft-versus-host disease (GVHD) is mediated by the same T cells and remains a significant clinical problem associated with substantial morbidity and mortality. In this issue of the
Todd V. Brennan, Yiping Yang
Many cancer-associated mutations that deregulate cellular metabolic responses to hypoxia also reprogram carbon metabolism to promote utilization of glutamine. In renal cell carcinoma (RCC), cells deficient in the von Hippel–Lindau (
Arimichi Okazaki, Paulo A. Gameiro, Danos Christodoulou, Laura Laviollette, Meike Schneider, Frances Chaves, Anat Stemmer-Rachamimov, Stephanie A. Yazinski, Richard Lee, Gregory Stephanopoulos, Lee Zou, Othon Iliopoulos
Accumulation of amyloid-β (Aβ) protein may cause synapse degeneration and cognitive impairment in Alzheimer’s disease (AD) by reactivating expression of the developmental synapse repressor protein Ephexin5 (also known as ARHGEF15). Here, we have reported that Aβ is sufficient to acutely promote the production of Ephexin5 in mature hippocampal neurons and in mice expressing human amyloid precursor protein (hAPP mice), a model for familial AD that produces high brain levels of Aβ. Ephexin5 expression was highly elevated in the hippocampi of human AD patients, indicating its potential relevance to AD. We also observed elevated Ephexin5 expression in the hippocampi of hAPP mice. Removal of Ephexin5 expression eliminated hippocampal dendritic spine loss and rescued AD-associated behavioral deficits in the hAPP mice. Furthermore, selective reduction of Ephexin5 expression using shRNA in the dentate gyrus of presymptomatic adolescent hAPP mice was sufficient to protect these mice from developing cognitive impairment. Thus, pathological elevation of Ephexin5 expression critically drives Aβ-induced memory impairment, and strategies aimed at reducing Ephexin5 levels may represent an effective approach to treating AD.
Gabrielle L. Sell, Thomas B. Schaffer, Seth S. Margolis
Mature B cell pools retain a substantial proportion of polyreactive and self-reactive clonotypes, suggesting that activation checkpoints exist to reduce the initiation of autoreactive B cell responses. Here, we have described a relationship among the B cell receptor (BCR), TLR9, and cytokine signals that regulate B cell responses to DNA-containing antigens. In both mouse and human B cells, BCR ligands that deliver a TLR9 agonist induce an initial proliferative burst that is followed by apoptotic death. The latter mechanism involves p38-dependent G1 cell-cycle arrest and subsequent intrinsic mitochondrial apoptosis and is shared by all preimmune murine B cell subsets and CD27– human B cells. Survival or costimulatory signals rescue B cells from this fate, but the outcome varies depending on the signals involved. B lymphocyte stimulator (BLyS) engenders survival and antibody secretion, whereas CD40 costimulation with IL-21 or IFN-γ promotes a T-bet+ B cell phenotype. Finally, in vivo immunization studies revealed that when protein antigens are conjugated with DNA, the humoral immune response is blunted and acquires features associated with T-bet+ B cell differentiation. We propose that this mechanism integrating BCR, TLR9, and cytokine signals provides a peripheral checkpoint for DNA-containing antigens that, if circumvented by survival and differentiative cues, yields B cells with the autoimmune-associated T-bet+ phenotype.
Vishal J. Sindhava, Michael A. Oropallo, Krishna Moody, Martin Naradikian, Lauren E. Higdon, Lin Zhou, Arpita Myles, Nathaniel Green, Kerstin Nündel, William Stohl, Amanda M. Schmidt, Wei Cao, Stephanie Dorta-Estremera, Taku Kambayashi, Ann Marshak-Rothstein, Michael P. Cancro
Duane retraction syndrome (DRS) is the most common form of congenital paralytic strabismus in humans and can result from α2-chimaerin (
Alicia A. Nugent, Jong G. Park, Yan Wei, Alan P. Tenney, Nicole M. Gilette, Michelle M. DeLisle, Wai-Man Chan, Long Cheng, Elizabeth C. Engle
Diseases caused by gene haploinsufficiency in humans commonly lack a phenotype in mice that are heterozygous for the orthologous factor, impeding the study of complex phenotypes and critically limiting the discovery of therapeutics. Laboratory mice have longer telomeres relative to humans, potentially protecting against age-related disease caused by haploinsufficiency. Here, we demonstrate that telomere shortening in NOTCH1-haploinsufficient mice is sufficient to elicit age-dependent cardiovascular disease involving premature calcification of the aortic valve, a phenotype that closely mimics human disease caused by NOTCH1 haploinsufficiency. Furthermore, progressive telomere shortening correlated with severity of disease, causing cardiac valve and septal disease in the neonate that was similar to the range of valve disease observed within human families. Genes that were dysregulated due to NOTCH1 haploinsufficiency in mice with shortened telomeres were concordant with proosteoblast and proinflammatory gene network alterations in human NOTCH1 heterozygous endothelial cells. These dysregulated genes were enriched for telomere-contacting promoters, suggesting a potential mechanism for telomere-dependent regulation of homeostatic gene expression. These findings reveal a critical role for telomere length in a mouse model of age-dependent human disease and provide an in vivo model in which to test therapeutic candidates targeting the progression of aortic valve disease.
Christina V. Theodoris, Foteini Mourkioti, Yu Huang, Sanjeev S. Ranade, Lei Liu, Helen M. Blau, Deepak Srivastava
Kit L. Shaw, Elizabeth Garabedian, Suparna Mishra, Provaboti Barman, Alejandra Davila, Denise Carbonaro, Sally Shupien, Christopher Silvin, Sabine Geiger, Barbara Nowicki, E. Monika Smogorzewska, Berkley Brown, Xiaoyan Wang, Satiro de Oliveira, Yeong Choi, Alan Ikeda, Dayna Terrazas, Pei-Yu Fu, Allen Yu, Beatriz Campo Fernandez, Aaron R. Cooper, Barbara Engel, Greg Podsakoff, Arumugam Balamurugan, Stacie Anderson, Linda Muul, G. Jayashree Jagadeesh, Neena Kapoor, John Tse, Theodore B. Moore, Ken Purdy, Radha Rishi, Kathey Mohan, Suzanne Skoda-Smith, David Buchbinder, Roshini S. Abraham, Andrew Scharenberg, Otto O. Yang, Kenneth Cornetta, David Gjertson, Michael Hershfield, Rob Sokolic, Fabio Candotti, Donald B. Kohn
It is well established that somatic genomic changes can influence phenotypes in cancer, but the role of adaptive changes in developmental disorders is less well understood. Here we have used next-generation sequencing approaches to identify de novo heterozygous mutations in sterile α motif domain–containing protein 9 (
Federica Buonocore, Peter Kühnen, Jenifer P. Suntharalingham, Ignacio Del Valle, Martin Digweed, Harald Stachelscheid, Noushafarin Khajavi, Mohammed Didi, Angela F. Brady, Oliver Blankenstein, Annie M. Procter, Paul Dimitri, Jerry K.H. Wales, Paolo Ghirri, Dieter Knöbl, Brigitte Strahm, Miriam Erlacher, Marcin W. Wlodarski, Wei Chen, George K. Kokai, Glenn Anderson, Deborah Morrogh, Dale A. Moulding, Shane A. McKee, Charlotte M. Niemeyer, Annette Grüters, John C. Achermann
The growth factor receptor Kit is involved in hematopoietic and nonhematopoietic development. Mice bearing
Pierre Cunin, Loka R. Penke, Jonathan N. Thon, Paul A. Monach, Tatiana Jones, Margaret H. Chang, Mary M. Chen, Imene Melki, Steve Lacroix, Yoichiro Iwakura, Jerry Ware, Michael F. Gurish, Joseph E. Italiano, Eric Boilard, Peter A. Nigrovic
Paradoxically, during early tumor development in many cancer types, TGF-β acts as a tumor suppressor, whereas in the advanced stages of these cancers, increased TGF-β expression is linked to high metastasis and poor prognosis. These findings suggest that unidentified mechanisms may function to rewire TGF-β signaling toward its prometastatic role in cancer cells. Our current study using non–small-cell lung carcinoma (NSCLC) cell lines, animal models, and clinical specimens demonstrates that suppression of SMAD2, with SMAD3 function intact, switches TGF-β–induced transcriptional responses to a prometastatic state. Importantly, we identified chaperonin containing TCP1 subunit 6A (CCT6A) as an inhibitor and direct binding protein of SMAD2 and found that CCT6A suppresses SMAD2 function in NSCLC cells and promotes metastasis. Furthermore, selective inhibition of SMAD3 or CCT6A efficiently suppresses TGF-β–mediated metastasis. Our findings provide a mechanism that directs TGF-β signaling toward its prometastatic arm and may contribute to the development of therapeutic strategies targeting TGF-β for NSCLC.
Zhe Ying, Han Tian, Yun Li, Rong Lian, Wei Li, Shanshan Wu, Hui-Zhong Zhang, Jueheng Wu, Lei Liu, Junwei Song, Hongyu Guan, Junchao Cai, Xun Zhu, Jun Li, Mengfeng Li
The integration of somatosensory information is generally assumed to be a function of the central nervous system (CNS). Here we describe fully functional GABAergic communication within rodent peripheral sensory ganglia and show that it can modulate transmission of pain-related signals from the peripheral sensory nerves to the CNS. We found that sensory neurons express major proteins necessary for GABA synthesis and release and that sensory neurons released GABA in response to depolarization. In vivo focal infusion of GABA or GABA reuptake inhibitor to sensory ganglia dramatically reduced acute peripherally induced nociception and alleviated neuropathic and inflammatory pain. In addition, focal application of GABA receptor antagonists to sensory ganglia triggered or exacerbated peripherally induced nociception. We also demonstrated that chemogenetic or optogenetic depolarization of GABAergic dorsal root ganglion neurons in vivo reduced acute and chronic peripherally induced nociception. Mechanistically, GABA depolarized the majority of sensory neuron somata, yet produced a net inhibitory effect on the nociceptive transmission due to the filtering effect at nociceptive fiber T-junctions. Our findings indicate that peripheral somatosensory ganglia represent a hitherto underappreciated site of somatosensory signal integration and offer a potential target for therapeutic intervention.
Xiaona Du, Han Hao, Yuehui Yang, Sha Huang, Caixue Wang, Sylvain Gigout, Rosmaliza Ramli, Xinmeng Li, Ewa Jaworska, Ian Edwards, Jim Deuchars, Yuchio Yanagawa, Jinlong Qi, Bingcai Guan, David B. Jaffe, Hailin Zhang, Nikita Gamper
Despite the benefit of insulin, blockade of autoimmune attack and regeneration of pancreatic islets are ultimate goals for the complete cure of type 1 diabetes (T1D). Long-term consumption of ω-3 polyunsaturated fatty acids (PUFAs) is known to suppress inflammatory processes, making these fatty acids candidates for the prevention and amelioration of autoimmune diseases. Here, we explored the preventative and therapeutic effects of ω-3 PUFAs on T1D. In NOD mice, dietary intervention with ω-3 PUFAs sharply reduced the incidence of T1D, modulated the differentiation of Th cells and Tregs, and decreased the levels of IFN-γ, IL-17, IL-6, and TNF-α. ω-3 PUFAs exerted similar effects on the differentiation of CD4+ T cells isolated from human peripheral blood mononuclear cells. The regulation of CD4+ T cell differentiation was mediated at least in part through ω-3 PUFA eicosanoid derivatives and by mTOR complex 1 (mTORC1) inhibition. Importantly, therapeutic intervention in NOD mice through nutritional supplementation or lentivirus-mediated expression of an ω-3 fatty acid desaturase, m
Xinyun Bi, Fanghong Li, Shanshan Liu, Yan Jin, Xin Zhang, Tao Yang, Yifan Dai, Xiaoxi Li, Allan Zijian Zhao
Dominantly inherited isolated polycystic liver disease (PCLD) consists of liver cysts that are radiologically and pathologically identical to those seen in autosomal dominant polycystic kidney disease, but without clinically relevant kidney cysts. The causative genes are known for fewer than 40% of PCLD index cases. Here, we have used whole exome sequencing in a discovery cohort of 102 unrelated patients who were excluded for mutations in the 2 most common PCLD genes,
Whitney Besse, Ke Dong, Jungmin Choi, Sohan Punia, Sorin V. Fedeles, Murim Choi, Anna-Rachel Gallagher, Emily B. Huang, Ashima Gulati, James Knight, Shrikant Mane, Esa Tahvanainen, Pia Tahvanainen, Simone Sanna-Cherchi, Richard P. Lifton, Terry Watnick, York P. Pei, Vicente E. Torres, Stefan Somlo
Developing erythrocytes take up exceptionally large amounts of iron, which must be transferred to mitochondria for incorporation into heme. This massive iron flux must be precisely controlled to permit the coordinated synthesis of heme and hemoglobin while avoiding the toxic effects of chemically reactive iron. In cultured animal cells, iron chaperones
Moon-Suhn Ryu, Deliang Zhang, Olga Protchenko, Minoo Shakoury-Elizeh, Caroline C. Philpott
Philipp S. Wild, Janine F. Felix, Arne Schillert, Alexander Teumer, Ming-Huei Chen, Maarten J.G. Leening, Uwe Völker, Vera Großmann, Jennifer A. Brody, Marguerite R. Irvin, Sanjiv J. Shah, Setia Pramana, Wolfgang Lieb, Reinhold Schmidt, Alice V. Stanton, Dörthe Malzahn, Albert Vernon Smith, Johan Sundström, Cosetta Minelli, Daniela Ruggiero, Leo-Pekka Lyytikäinen, Daniel Tiller, J. Gustav Smith, Claire Monnereau, Marco R. Di Tullio, Solomon K. Musani, Alanna C. Morrison, Tune H. Pers, Michael Morley, Marcus E. Kleber, AortaGen Consortium, Jayashri Aragam, Emelia J. Benjamin, Joshua C. Bis, Egbert Bisping, Ulrich Broeckel, CHARGE-Heart Failure Consortium, Susan Cheng, Jaap W. Deckers, Fabiola Del Greco M, Frank Edelmann, Myriam Fornage, Lude Franke, Nele Friedrich, Tamara B. Harris, Edith Hofer, Albert Hofman, Jie Huang, Alun D. Hughes, Mika Kähönen, KNHI investigators, Jochen Kruppa, Karl J. Lackner, Lars Lannfelt, Rafael Laskowski, Lenore J. Launer, Margrét Leosdottir, Honghuang Lin, Cecilia M. Lindgren, Christina Loley, Calum A. MacRae, Deborah Mascalzoni, Jamil Mayet, Daniel Medenwald, Andrew P. Morris, Christian Müller, Martina Müller-Nurasyid, Stefania Nappo, Peter M. Nilsson, Sebastian Nuding, Teresa Nutile, Annette Peters, Arne Pfeufer, Diana Pietzner, Peter P. Pramstaller, Olli T. Raitakari, Kenneth M. Rice, Fernando Rivadeneira, Jerome I. Rotter, Saku T. Ruohonen, Ralph L. Sacco, Tandaw E. Samdarshi, Helena Schmidt, Andrew S.P. Sharp, Denis C. Shields, Rossella Sorice, Nona Sotoodehnia, Bruno H. Stricker, Praveen Surendran, Simon Thom, Anna M. Töglhofer, André G. Uitterlinden, Rolf Wachter, Henry Völzke, Andreas Ziegler, Thomas Münzel, Winfried März, Thomas P. Cappola, Joel N. Hirschhorn, Gary F. Mitchell, Nicholas L. Smith, Ervin R. Fox, Nicole D. Dueker, Vincent W.V. Jaddoe, Olle Melander, Martin Russ, Terho Lehtimäki, Marina Ciullo, Andrew A. Hicks, Lars Lind, Vilmundur Gudnason, Burkert Pieske, Anthony J. Barron, Robert Zweiker, Heribert Schunkert, Erik Ingelsson, Kiang Liu, Donna K. Arnett, Bruce M. Psaty, Stefan Blankenberg, Martin G. Larson, Stephan B. Felix, Oscar H. Franco, Tanja Zeller, Ramachandran S. Vasan, Marcus Dörr
Acute graft-versus-host disease (aGVHD) is the most common complication for patients undergoing allogeneic stem cell transplantation. Despite extremely aggressive therapy targeting donor T cells, patients with grade III or greater aGVHD of the lower GI tract, who do not respond to therapy with corticosteroids, have a dismal prognosis. Thus, efforts to improve understanding of the function of local immune and non-immune cells in regulating the inflammatory process in the GI tract during aGVHD are needed. Here, we demonstrate, using murine models of allogeneic BMT, that type 2 innate lymphoid cells (ILC2s) in the lower GI tract are sensitive to conditioning therapy and show very limited ability to repopulate from donor bone marrow. Infusion of donor ILC2s was effective in reducing the lethality of aGVHD and in treating lower GI tract disease. ILC2 infusion was associated with reduced donor proinflammatory Th1 and Th17 cells, accumulation of donor myeloid-derived suppressor cells (MDSCs) mediated by ILC2 production of IL-13, improved GI tract barrier function, and a preserved graft-versus-leukemia (GVL) response. Collectively, these findings suggest that infusion of donor ILC2s to restore gastrointestinal tract homeostasis may improve treatment of severe lower GI tract aGVHD.
Danny W. Bruce, Heather E. Stefanski, Benjamin G. Vincent, Trisha A. Dant, Shannon Reisdorf, Hemamalini Bommiasamy, David A. Serody, Justin E. Wilson, Karen P. McKinnon, Warren D. Shlomchik, Paul M. Armistead, Jenny P.Y. Ting, John T. Woosley, Bruce R. Blazar, Dietmar M.W. Zaiss, Andrew N.J. McKenzie, James M. Coghill, Jonathan S. Serody
Tumors are capable of coopting hematopoietic cells to create a suitable microenvironment to support malignant growth. Here, we have demonstrated that upregulation of kinase insert domain receptor (KDR), also known as VEGFR2, in a myeloid cell sublineage is necessary for malignant progression of gliomas in transgenic murine models and is associated with high-grade tumors in patients. KDR expression increased in myeloid cells as myeloid-derived suppressor cells (MDSCs) accumulated, which was associated with the transformation and progression of low-grade fibrillary astrocytoma to high-grade anaplastic gliomas. KDR deficiency in murine BM-derived cells (BMDCs) suppressed the differentiation of myeloid lineages and reduced granulocytic/monocytic populations. The depletion of myeloid-derived KDR compromised its proangiogenic function, which inhibited the angiogenic switch necessary for malignant progression of low-grade to high-grade tumors. We also identified inhibitor of DNA binding protein 2 (ID2) as a key upstream regulator of KDR activation during myeloid differentiation. Deficiency of ID2 in BMDCs led to downregulation of KDR, suppression of proangiogenic myeloid cells, and prevention of low-grade to high-grade transition. Tumor-secreted TGF-β and granulocyte-macrophage CSF (GM-CSF) enhanced the KDR/ID2 signaling axis in BMDCs. Our results suggest that modulation of KDR/ID2 signaling may restrict tumor-associated myeloid cells and could potentially be a therapeutic strategy for preventing transformation of premalignant gliomas.
Yujie Huang, Prajwal Rajappa, Wenhuo Hu, Caitlin Hoffman, Babacar Cisse, Joon-Hyung Kim, Emilie Gorge, Rachel Yanowitch, William Cope, Emma Vartanian, Raymond Xu, Tuo Zhang, David Pisapia, Jenny Xiang, Jason Huse, Irina Matei, Hector Peinado, Jacqueline Bromberg, Eric Holland, Bi-sen Ding, Shahin Rafii, David Lyden, Jeffrey Greenfield
Gain-of-function (GOF) p53 mutations are observed frequently in most intractable human cancers and establish dependency for tumor maintenance and progression. While some of the genes induced by GOF p53 have been implicated in more rapid cell proliferation compared with p53-null cancer cells, the mechanism for dependency of tumor growth on mutant p53 is unknown. This report reveals a therapeutically targetable mechanism for GOF p53 dependency. We have shown that GOF p53 increases DNA replication origin firing, stabilizes replication forks, and promotes micronuclei formation, thus facilitating the proliferation of cells with genomic abnormalities. In contrast, absence or depletion of GOF p53 leads to decreased origin firing and a higher frequency of fork collapse in isogenic cells, explaining their poorer proliferation rate. Following genome-wide analyses utilizing ChIP-Seq and RNA-Seq, GOF p53–induced origin firing, micronuclei formation, and fork protection were traced to the ability of GOF p53 to transactivate cyclin A and CHK1. Highlighting the therapeutic potential of CHK1’s role in GOF p53 dependency, experiments in cell culture and mouse xenografts demonstrated that inhibition of CHK1 selectively blocked proliferation of cells and tumors expressing GOF p53. Our data suggest the possibility that checkpoint inhibitors could efficiently and selectively target cancers expressing GOF p53 alleles.
Shilpa Singh, Catherine A. Vaughan, Rebecca A. Frum, Steven R. Grossman, Sumitra Deb, Swati Palit Deb
Cancer cells preferentially utilize glucose and glutamine, which provide macromolecules and antioxidants that sustain rapid cell division. Metabolic reprogramming in cancer drives an increased glycolytic rate that supports maximal production of these nutrients. The folate cycle, through transfer of a carbon unit between tetrahydrofolate and its derivatives in the cytoplasmic and mitochondrial compartments, produces other metabolites that are essential for cell growth, including nucleotides, methionine, and the antioxidant NADPH. Here, using hepatocellular carcinoma (HCC) as a cancer model, we have observed a reduction in growth rate upon withdrawal of folate. We found that an enzyme in the folate cycle, methylenetetrahydrofolate dehydrogenase 1–like (MTHFD1L), plays an essential role in support of cancer growth. We determined that MTHFD1L is transcriptionally activated by NRF2, a master regulator of redox homeostasis. Our observations further suggest that MTHFD1L contributes to the production and accumulation of NADPH to levels that are sufficient to combat oxidative stress in cancer cells. The elevation of oxidative stress through MTHFD1L knockdown or the use of methotrexate, an antifolate drug, sensitizes cancer cells to sorafenib, a targeted therapy for HCC. Taken together, our study identifies MTHFD1L in the folate cycle as an important metabolic pathway in cancer cells with the potential for therapeutic targeting.
Derek Lee, Iris Ming-Jing Xu, David Kung-Chun Chiu, Robin Kit-Ho Lai, Aki Pui-Wah Tse, Lynna Lan Li, Cheuk-Ting Law, Felice Ho-Ching Tsang, Larry Lai Wei, Cerise Yuen-Ki Chan, Chun-Ming Wong, Irene Oi-Lin Ng, Carmen Chak-Lui Wong
Worldwide epidemics of metabolic diseases, including liver steatosis, are associated with an increased frequency of malignancies, showing the highest positive correlation for liver cancer. The heterogeneity of liver cancer represents a clinical challenge. In liver, the transcription factor PPARγ promotes metabolic adaptations of lipogenesis and aerobic glycolysis under the control of Akt2 activity, but the role of PPARγ in liver tumorigenesis is unknown. Here we have combined preclinical mouse models of liver cancer and genetic studies of a human liver biopsy atlas with the aim of identifying putative therapeutic targets in the context of liver steatosis and cancer. We have revealed a protumoral interaction of Akt2 signaling with hepatocyte nuclear factor 1α (HNF1α) and PPARγ, transcription factors that are master regulators of hepatocyte and adipocyte differentiation, respectively. Akt2 phosphorylates and inhibits HNF1α, thus relieving the suppression of hepatic PPARγ expression and promoting tumorigenesis. Finally, we observed that pharmacological inhibition of PPARγ is therapeutically effective in a preclinical murine model of steatosis-associated liver cancer. Taken together, our studies in humans and mice reveal that Akt2 controls hepatic tumorigenesis through crosstalk between HNF1α and PPARγ.
Cecilia Patitucci, Gabrielle Couchy, Alessia Bagattin, Tatiana Cañeque, Aurélien de Reyniès, Jean-Yves Scoazec, Raphaël Rodriguez, Marco Pontoglio, Jessica Zucman-Rossi, Mario Pende, Ganna Panasyuk
Mutations in the X-linked gene encoding methyl-CpG–binding protein 2 (MeCP2) cause Rett syndrome (RTT), a neurological disorder affecting cognitive development, respiration, and motor function. Genetic restoration of MeCP2 expression reverses RTT-like phenotypes in mice, highlighting the need to search for therapeutic approaches. Here, we have developed knockin mice recapitulating the most common RTT-associated missense mutation, MeCP2 T158M. We found that the T158M mutation impaired MECP2 binding to methylated DNA and destabilized MeCP2 protein in an age-dependent manner, leading to the development of RTT-like phenotypes in these mice. Genetic elevation of MeCP2 T158M expression ameliorated multiple RTT-like features, including motor dysfunction and breathing irregularities, in both male and female mice. These improvements were accompanied by increased binding of MeCP2 T158M to DNA. Further, we found that the ubiquitin/proteasome pathway was responsible for MeCP2 T158M degradation and that proteasome inhibition increased MeCP2 T158M levels. Together, these findings demonstrate that increasing MeCP2 T158M protein expression is sufficient to mitigate RTT-like phenotypes and support the targeting of MeCP2 T158M expression or stability as an alternative therapeutic approach.
Janine M. Lamonica, Deborah Y. Kwon, Darren Goffin, Polina Fenik, Brian S. Johnson, Yue Cui, Hengyi Guo, Sigrid Veasey, Zhaolan Zhou
Proinflammatory cytokine overproduction and excessive cell death, coupled with impaired clearance of apoptotic cells, have been implicated as causes of failure to resolve gut inflammation in inflammatory bowel diseases. Here we have found that dendritic cells expressing the apoptotic cell–recognizing receptor CD300f play a crucial role in regulating gut inflammatory responses in a murine model of colonic inflammation. CD300f-deficient mice failed to resolve dextran sulfate sodium–induced colonic inflammation as a result of defects in dendritic cell function that were associated with abnormal accumulation of apoptotic cells in the gut. CD300f-deficient dendritic cells displayed hyperactive phagocytosis of apoptotic cells, which stimulated excessive TNF-α secretion predominantly from dendritic cells. This, in turn, induced secondary IFN-γ overproduction by colonic T cells, leading to prolonged gut inflammation. Our data highlight a previously unappreciated role for dendritic cells in controlling gut homeostasis and show that CD300f-dependent regulation of apoptotic cell uptake is essential for suppressing overactive dendritic cell–mediated inflammatory responses, thereby controlling the development of chronic gut inflammation.
Ha-Na Lee, Linjie Tian, Nicolas Bouladoux, Jacquice Davis, Mariam Quinones, Yasmine Belkaid, John E. Coligan, Konrad Krzewski
The eleven-nineteen leukemia (ENL) protein family, composed of ENL and AF9, is a common component of 3 transcriptional modulators: AF4–ENL–P-TEFb complex (AEP), DOT1L-AF10-ENL complex (referred to as the DOT1L complex) and polycomb-repressive complex 1 (PRC1). Each complex associates with chromatin via distinct mechanisms, conferring different transcriptional properties including activation, maintenance, and repression. The mixed-lineage leukemia (
Hiroshi Okuda, Boban Stanojevic, Akinori Kanai, Takeshi Kawamura, Satoshi Takahashi, Hirotaka Matsui, Akifumi Takaori-Kondo, Akihiko Yokoyama
Natalia Rakova, Kento Kitada, Kathrin Lerchl, Anke Dahlmann, Anna Birukov, Steffen Daub, Christoph Kopp, Tetyana Pedchenko, Yahua Zhang, Luis Beck, Bernd Johannes, Adriana Marton, Dominik N. Müller, Manfred Rauh, Friedrich C. Luft, Jens Titze
Natriuretic regulation of extracellular fluid volume homeostasis includes suppression of the renin-angiotensin-aldosterone system, pressure natriuresis, and reduced renal nerve activity, actions that concomitantly increase urinary Na+ excretion and lead to increased urine volume. The resulting natriuresis-driven diuretic water loss is assumed to control the extracellular volume. Here, we have demonstrated that urine concentration, and therefore regulation of water conservation, is an important control system for urine formation and extracellular volume homeostasis in mice and humans across various levels of salt intake. We observed that the renal concentration mechanism couples natriuresis with correspondent renal water reabsorption, limits natriuretic osmotic diuresis, and results in concurrent extracellular volume conservation and concentration of salt excreted into urine. This water-conserving mechanism of dietary salt excretion relies on urea transporter–driven urea recycling by the kidneys and on urea production by liver and skeletal muscle. The energy-intense nature of hepatic and extrahepatic urea osmolyte production for renal water conservation requires reprioritization of energy and substrate metabolism in liver and skeletal muscle, resulting in hepatic ketogenesis and glucocorticoid-driven muscle catabolism, which are prevented by increasing food intake. This natriuretic-ureotelic, water-conserving principle relies on metabolism-driven extracellular volume control and is regulated by concerted liver, muscle, and renal actions.
Kento Kitada, Steffen Daub, Yahua Zhang, Janet D. Klein, Daisuke Nakano, Tetyana Pedchenko, Louise Lantier, Lauren M. LaRocque, Adriana Marton, Patrick Neubert, Agnes Schröder, Natalia Rakova, Jonathan Jantsch, Anna E. Dikalova, Sergey I. Dikalov, David G. Harrison, Dominik N. Müller, Akira Nishiyama, Manfred Rauh, Raymond C. Harris, Friedrich C. Luft, David H. Wasserman, Jeff M. Sands, Jens Titze
Programmed death ligand-1 (PD-L1) interacts with programmed death-1 (PD-1) and the immunostimulatory molecule CD80 and functions as a checkpoint to regulate immune responses. The interaction of PD-L1 with CD80 alone has been shown to exacerbate the severity of graft-versus-host disease (GVHD), whereas costimulation of CD80 and PD-1 ameliorates GVHD. Here we have demonstrated that temporary depletion of donor CD4+ T cells early after hematopoietic cell transplantation effectively prevents GVHD while preserving strong graft-versus-leukemia (GVL) effects in allogeneic and xenogeneic murine GVHD models. Depletion of donor CD4+ T cells increased serum IFN-γ but reduced IL-2 concentrations, leading to upregulation of PD-L1 expression by recipient tissues and donor CD8+ T cells. In GVHD target tissues, the interactions of PD-L1 with PD-1 on donor CD8+ T cells cause anergy, exhaustion, and apoptosis, thereby preventing GVHD. In lymphoid tissues, the interactions of PD-L1 with CD80 augment CD8+ T cell expansion without increasing anergy, exhaustion, or apoptosis, resulting in strong GVL effects. These results indicate that the outcome of PD-L1–mediated signaling in CD8+ T cells depends on the presence or absence of CD4+ T cells, the nature of the interacting receptor expressed by CD8+ T cells, and the tissue environment in which the signaling occurs.
Xiong Ni, Qingxiao Song, Kaniel Cassady, Ruishu Deng, Hua Jin, Mingfeng Zhang, Haidong Dong, Stephen Forman, Paul J. Martin, Yuan-Zhong Chen, Jianmin Wang, Defu Zeng
The postsynaptic scaffolding protein SH3 and multiple ankyrin repeat domains 3 (SHANK3) is critical for the development and function of glutamatergic synapses. Disruption of the SHANK3-encoding gene has been strongly implicated as a monogenic cause of autism, and
Wenting Wang, Chenchen Li, Qian Chen, Marie-Sophie van der Goes, James Hawrot, Annie Y. Yao, Xian Gao, Congyi Lu, Ying Zang, Qiangge Zhang, Katherine Lyman, Dongqing Wang, Baolin Guo, Shengxi Wu, Charles R. Gerfen, Zhanyan Fu, Guoping Feng
Inborn errors of DNA repair or replication underlie a variety of clinical phenotypes. We studied 5 patients from 4 kindreds, all of whom displayed intrauterine growth retardation, chronic neutropenia, and NK cell deficiency. Four of the 5 patients also had postnatal growth retardation. The association of neutropenia and NK cell deficiency, which is unusual among primary immunodeficiencies and bone marrow failures, was due to a blockade in the bone marrow and was mildly symptomatic. We discovered compound heterozygous rare mutations in Go-Ichi-Ni-San (GINS) complex subunit 1 (
Julien Cottineau, Molly C. Kottemann, Francis P. Lach, Young-Hoon Kang, Frédéric Vély, Elissa K. Deenick, Tomi Lazarov, Laure Gineau, Yi Wang, Andrea Farina, Marie Chansel, Lazaro Lorenzo, Christelle Piperoglou, Cindy S. Ma, Patrick Nitschke, Aziz Belkadi, Yuval Itan, Bertrand Boisson, Fabienne Jabot-Hanin, Capucine Picard, Jacinta Bustamante, Céline Eidenschenk, Soraya Boucherit, Nathalie Aladjidi, Didier Lacombe, Pascal Barat, Waseem Qasim, Jane A. Hurst, Andrew J. Pollard, Holm H. Uhlig, Claire Fieschi, Jean Michon, Vladimir P. Bermudez, Laurent Abel, Jean-Pierre de Villartay, Frédéric Geissmann, Stuart G. Tangye, Jerard Hurwitz, Eric Vivier, Jean-Laurent Casanova, Agata Smogorzewska, Emmanuelle Jouanguy
Pancreatic ductal adenocarcinoma (PDAC) is almost uniformly fatal; however, some improvement in overall survival has been achieved with the introduction of nanocarriers that deliver irinotecan or paclitaxel. Although it is generally assumed that nanocarriers rely principally on abnormal leaky vasculature for tumor access, a transcytosis transport pathway that is regulated by neuropilin-1 (NRP-1) has recently been reported. NRP-1–mediated transport can be triggered by the cyclic tumor-penetrating peptide iRGD. In a KRAS-induced orthotopic PDAC model, coadministration of iRGD enhanced the uptake of an irinotecan-loaded silicasome carrier that comprises lipid bilayer–coated mesoporous silica nanoparticles (MSNPs); this uptake resulted in enhanced survival and markedly reduced metastasis. Further, ultrastructural imaging of the treated tumors revealed that iRGD coadministration induced a vesicular transport pathway that carried Au-labeled silicacomes from the blood vessel lumen to a perinuclear site within cancer cells. iRGD-mediated enhancement of silicasome uptake was also observed in patient-derived xenografts, commensurate with the level of NRP-1 expression on tumor blood vessels. These results demonstrate that iRGD enhances the efficacy of irinotecan-loaded silicasome–based therapy and may be a suitable adjuvant in nanoparticle-based treatments for PDAC.
Xiangsheng Liu, Paulina Lin, Ian Perrett, Joshua Lin, Yu-Pei Liao, Chong Hyun Chang, Jinhong Jiang, Nanping Wu, Timothy Donahue, Zev Wainberg, Andre E. Nel, Huan Meng