Issue published June 3, 2019 Previous issue | Next issue
On the cover: Bariatric surgery’s effects on bone and marrow niche
In this issue of the JCI, Li et al. examined bone loss in a mouse model of bariatric surgery, reporting that impaired bone mineralization and formation correlated with an expansion of myeloid cells in the bone marrow and increased circulating neutrophils, which were mediated by the neutrophil-stimulating factor G-CSF. This issue’s cover conceptualizes VSG’s effects on bone, the bone marrow niche, and circulating cells. Image credit: Ziru Li, Devika P. Bagchi, Callie A. Corsa, and other members of the MacDougald lab.
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Commentaries
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Abstract
Chimeric antigen receptor (CAR) T cells have been shown to successfully treat some hematopoietic malignancies. Recognition of a relevant target on malignant cells and the proper costimulatory molecule are essential for CAR T cell efficacy. In this issue of the JCI, Cohen et al. conducted an early phase trial to evaluate B cell maturation antigen–targeting (BCMA-targeting) CAR T cells in patients with refractory multiple myeloma. Patients who received the highest dose of BCMA-targeting CAR T cells in combination with lymphodepletion had the greatest response. The results of the study provide further support for the use of BCMA-targeting CAR T cells for myeloma, and reiterate the importance of space and cell dose for CAR T cell success.
Authors
Ivan Borrello, Philip H. Imus
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Glucocorticoids (GCs) are essential for proper glycemic control, but in excess, can lead to hyperglycemia and diabetes. In this issue of the JCI, Cui et al. elucidate a mechanism by which GCs regulate gluconeogenesis utilizing the transcription factor Krüppel-like factor 9 (KLF9) in physiology and disease settings. They report that KLF9 is a GC-inducible factor that ultimately increases the transcription of proliferator-activated receptor γ coactivator 1 α (PGC1α), resulting in gluconeogenesis. Given the high incidence of GC-induced diabetes, identification of this signaling axis provides, not only critical scientific insight, but also a foundation for preventative therapies for patients receiving chronic GC treatment.
Authors
David R. Sweet, Liyan Fan, Mukesh K. Jain
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White adipose tissue (WAT) dysfunction is generally thought to promote the development of alcoholic liver disease (ALD) in alcoholics by releasing free fatty acids and inflammatory mediators. This explains, at least in part, the synergistic or additive effects of alcohol and obesity on liver disease progression. In this issue of the JCI, Shen et al. establish a previously unrecognized concept that brain alcohol sensing enhances thermogenesis of brown adipose tissue (BAT) through sympathetic nerve activation. BAT functions as hepatoprotective machinery to counteract the development of ALD, implying a therapeutic potential of BAT activity modulation for the treatment of ALD.
Authors
Seonghwan Hwang, Bin Gao
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Vertical sleeve gastrectomy (VSG) is an effective therapeutic approach for obesity and type 2 diabetes but is associated with osteoporosis. In this issue of the JCI, Li et al. report that VSG rapidly reduces bone mass, as observed in humans, via rapid demineralization and decreased bone formation, independent of weight loss or Ca2+/vitamin D deficiency. VSG also reduces bone marrow adipose tissue, in part via increased granulocyte–colony stimulating factor (G-CSF). The interplay between VSG-mediated effects on systemic metabolism and bone biology remain to be investigated. These findings suggest novel mechanisms and therapeutic targets for bariatric surgery–induced osteoporosis.
Authors
Soravis Osataphan, Mary Elizabeth Patti
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African Americans are at increased risk of cancer and associated mortalities compared with European American populations. Socioeconomic, cultural, and biological factors have been implicated in this discrepancy. In this issue of the JCI, Piyarathna et al. identify a set of genes that are upregulated in a number of tumor types in African American cancer patients as compared with European American patients. These genes were associated with enhanced oxidative phosphorylation and upregulation of transcription factors that promote mitochondrial biogenesis, resulting in greater numbers of mitochondria in tumor samples from African American subjects. Together, these results indicate that mitochondria dysfunction may underlie the increased cancer incidence and poor outcomes observed in African American patients.
Authors
Jennifer L. Beebe-Dimmer, Kathleen A. Cooney
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For high-risk and refractory hematological malignancies, allogeneic hematopoietic stem cell transplantation (alloHSCT) is the only available curative therapy, with benefits derived from the antigenic disparity between recipient cancer and the incoming immune system. This immunologic mismatch can also lead to lethal graft-versus-host disease (GVHD), and immunosuppression strategies, including high-dose posttransplantation cyclophosphamide (PTCy), have been developed to allow for safe alloHSCT delivery. In this issue of JCI, Wachsmuth et al. present the results of preclinical studies designed to evaluate the mechanisms that underlie efficacy of PTCy after alloHSCT. The results of this study challenge previous reports indicating that alloreactive T cell elimination and thymic clonal deletion are primary mediators of PTCy efficacy and provide strong evidence to support FoxP3+CD4+ Tregs as important effectors of PTCy benefits.
Authors
Vedran Radojcic, Leo Luznik
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Acute kidney injury (AKI) is one of the most important risk factors for chronic and progressive kidney disease, leading to end-stage kidney failure. Tubule epithelial regeneration leads to the resolution of renal failure in AKI. Failure of tubule epithelial regeneration leads to concomitant hypoxia from loss of microcirculation, which serves as a critical factor leading to chronic kidney disease. In this issue of the JCI, Li et al. show that hypoxia activates the stress-responsive transcription factor FoxO3. Increased FoxO3 protein abundance leads to alterations in tubular epithelial autophagy and metabolism, highlighting an important mechanism causing permanent renal damage even after an acute injury.
Authors
Xiangchen Gu, Archana Raman, Katalin Susztak
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The T cell receptor (TCR) repertoire is diverse, thus allowing recognition of a wide range of pathogens by T cells. In humans, the study of the formation of TCR repertoires is problematic because of the difficulty in performing investigations in vivo. In this issue of the JCI, Khosravi-Maharlooei and colleagues describe a new humanized mouse model that allows direct investigations on this topic. Using high-throughput and single-cell TCR–complementarity-determining region 3 β (TCR-CDR3β) sequencing, the authors were able to demonstrate that human thymic selection is a major driver of TCR sequence sharing, also implicating a preferential selection of shared cross-reactive CDR3βs during repertoire formation.
Authors
Antonio La Cava
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The study of beige adipose tissue (BeAT) has recently gained popularity because of its potential as a therapeutic target for the treatment of obesity and other metabolic disorders. While BeAT regulation is well understood in adults, the critical signals regulating BeAT during infant development need to be better defined. The bioactive components in breast milk have been primarily studied in the context of immunity. In this issue of the JCI, Yu and Dilbaz et al. identify how a class of breast milk–specific lipid mediators referred to as alkylglycerols (AKGs) maintain BeAT in infants and prevent the transdifferentiation of BeAT into lipid-storing white adipose tissue (WAT).
Authors
Christy M. Gliniak, Philipp E. Scherer
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Excessive excretion of oxalate in the urine results in the formation of calcium oxalate crystals and subsequent kidney stone formation. Severe forms of hyperoxaluria, including genetic forms and those that result from ethylene glycol poisoning, can result in end-stage renal disease. Therapeutic interventions are limited and often rely on dietary intervention. In this issue of the JCI, Le Dudal and colleagues demonstrate that the lactate dehydrogenase 5 inhibitor (LDH5) stiripentol reduces urinary oxalate excretion. Importantly, stiripentol treatment of a single individual with primary hyperoxaluria reduced the urinary oxalate excretion. Together, these results support further evaluation of LDH5 as a therapeutic target for hyperoxaluria.
Authors
Jacob S. Stevens, Qais Al-Awqati
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In this issue of the JCI, Capitano et al. demonstrate that the secreted form of the DNA-binding chromatin factor DEK regulates hematopoiesis. It is known that DEK can be secreted by macrophages and other cells, but no function has been attached to secreted DEK. Capitano et al. showed that extracellular DEK activates signaling through the CXCL2 receptor, which in turn enhances the proliferation of hematopoietic stem cells and decreases hematopoietic progenitor cell numbers both in vivo and in vitro. These results offer the opportunity to expand transplantable stem cells to improve outcomes in patients undergoing bone marrow transplant.
Authors
David M. Bodine
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Growing evidence implicates altered mTORC1 signaling cascades in the pathophysiology of depression, suggesting that direct modulation of mTORC1 signaling may offer novel therapeutic potential. In this issue of the JCI, Kato and colleagues reported that administration of NV-5138, a recently developed synthetic leucine analog, has a rapid and sustained antidepressant action in rat models via activation of mTORC1 signaling. The investigators also found that the antidepressant effect of NV-5138 is mediated by upregulation of brain-derived neurotrophic factor (BDNF) signaling and that NV-5138 treatment produces rapid synaptic responses in the medial prefrontal cortex. These findings highlight the direct activation of mTORC1 signaling as a potential pharmacological intervention for the treatment of depression.
Authors
Yuto Hasegawa, Xiaolei Zhu, Atsushi Kamiya
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Research Articles
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Abstract
BACKGROUND. CAR T cells are a promising therapy for hematologic malignancies. B cell maturation antigen (BCMA) is a rational target in multiple myeloma (MM). METHODS. We conducted a phase I study of autologous T cells lentivirally transduced with a fully human, BCMA-specific CAR containing CD3ζ and 4-1BB signaling domains (CART-BCMA), in subjects with relapsed/refractory MM. Twenty-five subjects were treated in 3 cohorts as follows: cohort 1, 1 × 108 to 5 × 108 CART-BCMA cells alone; cohort 2, cyclophosphamide (Cy) 1.5 g/m2 plus 1 × 107 to 5 × 107 CART-BCMA cells; cohort 3, Cy 1.5 g/m2 plus 1 × 108 to 5 × 108 CART-BCMA cells. No prespecified BCMA expression level was required. RESULTS. CART-BCMA cells were manufactured and expanded in all subjects. Toxicities included cytokine release syndrome and neurotoxicity, which were grade 3–4 in 8 (32%) and 3 (12%) subjects, respectively, and reversible. One subject died at day 24 from candidemia and progressive myeloma, following treatment for severe cytokine release syndrome and encephalopathy. Responses (based on treated subjects) were seen in 4 of 9 (44%) in cohort 1, 1 of 5 (20%) in cohort 2, and 7 of 11 (64%) in cohort 3, including 5 partial, 5 very good partial, and 2 complete responses, 3 of which were ongoing at 11, 14, and 32 months. Decreased BCMA expression on residual MM cells was noted in responders; expression increased at progression in most. Responses and CART-BCMA expansion were associated with CD4/CD8 T cell ratio and frequency of CD45RO–CD27+CD8+ T cells in the premanufacturing leukapheresis product. CONCLUSION. CART-BCMA infusions with or without lymphodepleting chemotherapy are clinically active in heavily pretreated patients with MM. TRIAL REGISTRATION. NCT02546167. FUNDING. University of Pennsylvania-Novartis Alliance and NIH.
Authors
Adam D. Cohen, Alfred L. Garfall, Edward A. Stadtmauer, J. Joseph Melenhorst, Simon F. Lacey, Eric Lancaster, Dan T. Vogl, Brendan M. Weiss, Karen Dengel, Annemarie Nelson, Gabriela Plesa, Fang Chen, Megan M. Davis, Wei-Ting Hwang, Regina M. Young, Jennifer L. Brogdon, Randi Isaacs, Iulian Pruteanu-Malinici, Don L. Siegel, Bruce L. Levine, Carl H. June, Michael C. Milone
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Neurofascin-155 (Nfasc155) is an essential glial cell adhesion molecule expressed in paranodal septate-like junctions of peripheral and central myelinated axons. The genetic deletion of Nfasc155 results in the loss of septate-like junctions and in conduction slowing. In humans, IgG4 antibodies against Nfasc155 are implicated in the pathogenesis of chronic inflammatory demyelinating polyneuropathy (CIDP). These antibodies are associated with an aggressive onset, a refractoriness to intravenous immunoglobulin, and tremor of possible cerebellar origin. Here, we examined the pathogenic effects of patient-derived anti-Nfasc155 IgG4. These antibodies did not inhibit the ability of Nfasc155 to complex with its axonal partners contactin-1 and CASPR1 or induce target internalization. Passive transfer experiments revealed that IgG4 antibodies targeted Nfasc155 on Schwann cell surfaces, and diminished Nfasc155 protein levels and prevented paranodal complex formation in neonatal animals. In adult animals, chronic intrathecal infusions of antibodies also induced the loss of Nfasc155 and of paranodal specialization and resulted in conduction alterations in motor nerves. These results indicate that anti-Nfasc155 IgG4 antibodies perturb conduction in the absence of demyelination, validating the existence of paranodopathy. These results also shed light on the mechanisms regulating protein insertion at paranodes.
Authors
Constance Manso, Luis Querol, Cinta Lleixà, Mallory Poncelet, Mourad Mekaouche, Jean-Michel Vallat, Isabel Illa, Jérôme J. Devaux
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Exosomes, as functional paracrine units of therapeutic cells, can partially reproduce the reparative properties of their parental cells. The constitution of exosomes, as well as their biological activity, largely depends on the cells that secrete them. We isolated exosomes from explant-derived cardiac stromal cells from patients with heart failure (FEXO) or from normal donor hearts (NEXO) and compared their regenerative activities in vitro and in vivo. Patients in the FEXO group exhibited an impaired ability to promote endothelial tube formation and cardiomyocyte proliferation in vitro. Intramyocardial injection of NEXO resulted in structural and functional improvements in a murine model of acute myocardial infarction. In contrast, FEXO therapy exacerbated cardiac function and left ventricular remodeling. microRNA array and PCR analysis revealed dysregulation of miR-21-5p in FEXO. Restoring miR-21-5p expression rescued FEXO’s reparative function, whereas blunting miR-21-5p expression in NEXO diminished its therapeutic benefits. Further mechanistic studies revealed that miR-21-5p augmented Akt kinase activity through the inhibition of phosphatase and tensin homolog. Taken together, the heart failure pathological condition altered the miR cargos of cardiac-derived exosomes and impaired their regenerative activities. miR-21-5p contributes to exosome-mediated heart repair by enhancing angiogenesis and cardiomyocyte survival through the phosphatase and tensin homolog/Akt pathway.
Authors
Li Qiao, Shiqi Hu, Suyun Liu, Hui Zhang, Hong Ma, Ke Huang, Zhenhua Li, Teng Su, Adam Vandergriff, Junnan Tang, Tyler Allen, Phuong-Uyen Dinh, Jhon Cores, Qi Yin, Yongjun Li, Ke Cheng
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Systemic lupus erythematosus (SLE) is a complex autoimmune disease with genetic and environmental contributions. Hallmarks of the disease are the appearance of immune complexes (IC) containing autoreactive Abs and TLR-activating nucleic acids, whose deposition in kidney glomeruli is suspected to promote tissue injury and glomerulonephritis (GN). Here, using a mouse model based on the human SLE susceptibility locus TNFAIP3-interacting protein 1 (TNIP1, also known as ABIN1), we investigated the pathogenesis of GN. We found that GN was driven by TLRs but, remarkably, proceeded independently of ICs. Rather, disease in 3 different mouse models and patients with SLE was characterized by glomerular accumulation of patrolling monocytes (PMos), a cell type with an emerging key function in vascular inflammation. Consistent with such function in GN, monocyte-specific deletion of ABIN1 promoted kidney disease, whereas selective elimination of PMos provided protection. In contrast to GN, PMo elimination did not protect from reduced survival or disease symptoms such as IC generation and splenomegaly, suggesting that GN and other inflammatory processes are governed by distinct pathogenic mechanisms. These data identify TLR-activated PMos as the principal component of an intravascular process that contributes to glomerular inflammation and kidney injury.
Authors
Jeeba Kuriakose, Vanessa Redecke, Cliff Guy, Jingran Zhou, Ruiqiong Wu, Sirish K. Ippagunta, Heather Tillman, Patrick D. Walker, Peter Vogel, Hans Häcker
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Chronic glucocorticoid therapy has serious side effects, including diabetes and fatty liver. However, the molecular mechanisms responsible for steroid-induced diabetes remain largely enigmatic. Here, we show that hepatic Krüppel-like factor 9 (Klf9) gene expression is induced by dexamethasone and fasting. The overexpression of Klf9 in primary hepatocytes strongly stimulated Pgc1a gene expression through direct binding to its promoter, thereby activating the gluconeogenic program. However, Klf9 mutation abolished the stimulatory effect of dexamethasone on cellular glucose output. Adenovirus-mediated overexpression of KLF9 in the mouse liver markedly increased blood glucose levels and impaired glucose tolerance. Conversely, both global Klf9-mutant mice and liver-specific Klf9-deleted mice displayed fasting hypoglycemia. Moreover, the knockdown of Klf9 in the liver in diabetic mouse models, including ob/ob and db/db mice, markedly lowered fasting blood glucose levels. Notably, hepatic Klf9 deficiency in mice alleviated hyperglycemia induced by chronic dexamethasone treatment. These results suggest a critical role for KLF9 in the regulation of hepatic glucose metabolism and identify hepatic induction of KLF9 as a mechanism underlying glucocorticoid therapy–induced diabetes.
Authors
Anfang Cui, Heng Fan, Yinliang Zhang, Yujie Zhang, Dong Niu, Shuainan Liu, Quan Liu, Wei Ma, Zhufang Shen, Lian Shen, Yanling Liu, Huabing Zhang, Yuan Xue, Ying Cui, Qinghua Wang, Xinhua Xiao, Fude Fang, Jichun Yang, Qinghua Cui, Yongsheng Chang
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Oncolytic virotherapy has been proposed as an ablative and immunostimulatory treatment strategy for solid tumors that are resistant to immunotherapy alone; however, there is a need to optimize host immune activation using preclinical immunocompetent models in previously untested common adult tumors. We studied a modified oncolytic myxoma virus (MYXV) that shows high efficiency for tumor-specific cytotoxicity in small-cell lung cancer (SCLC), a neuroendocrine carcinoma with high mortality and modest response rates to immune checkpoint inhibitors. Using an immunocompetent SCLC mouse model, we demonstrated the safety of intrapulmonary MYXV delivery with efficient tumor-specific viral replication and cytotoxicity associated with induction of immune cell infiltration. We observed increased SCLC survival following intrapulmonary MYXV that was enhanced by combined low-dose cisplatin. We also tested intratumoral MYXV delivery and observed immune cell infiltration associated with tumor necrosis and growth inhibition in syngeneic murine allograft tumors. Freshly collected primary human SCLC tumor cells were permissive to MYXV and intratumoral delivery into patient-derived xenografts resulted in extensive tumor necrosis. We confirmed MYXV cytotoxicity in classic and variant SCLC subtypes as well as cisplatin-resistant cells. Data from 26 SCLC human patients showed negligible immune cell infiltration, supporting testing MYXV as an ablative and immune-enhancing therapy.
Authors
Patrick Kellish, Daniil Shabashvili, Masmudur M. Rahman, Akbar Nawab, Maria V. Guijarro, Min Zhang, Chunxia Cao, Nissin Moussatche, Theresa Boyle, Scott Antonia, Mary Reinhard, Connor Hartzell, Michael Jantz, Hiren J. Mehta, Grant McFadden, Frederic J. Kaye, Maria Zajac-Kaye
×Abstract
Nonapoptotic forms of cell death can trigger sterile inflammation through the release of damage-associated molecular patterns, which are recognized by innate immune receptors. However, despite years of investigation, the mechanisms that initiate inflammatory responses after heart transplantation remain elusive. Here, we demonstrate that ferrostatin-1 (Fer-1), a specific inhibitor of ferroptosis, decreases the levels of pro-ferroptotic hydroperoxy-arachidonoyl-phosphatidylethanolamine, reduces cardiomyocyte cell death, and blocks neutrophil recruitment following heart transplantation. Inhibition of necroptosis had no effect on neutrophil trafficking in cardiac grafts. We extend these observations to a model of coronary artery ligation–induced myocardial ischemia reperfusion injury (IRI), in which inhibition of ferroptosis resulted in reduced infarct size, improved left ventricular (LV) systolic function, and reduced LV remodeling. Using intravital imaging of cardiac transplants, we show that ferroptosis orchestrates neutrophil recruitment to injured myocardium by promoting adhesion of neutrophils to coronary vascular endothelial cells through a TLR4/Trif/type I IFN signaling pathway. Thus, we have discovered that inflammatory responses after cardiac transplantation are initiated through ferroptotic cell death and TLR4/Trif-dependent signaling in graft endothelial cells. These findings provide a platform for the development of therapeutic strategies for heart transplant recipients and patients who are vulnerable to IRI following restoration of coronary blood flow.
Authors
Wenjun Li, Guoshuai Feng, Jason M. Gauthier, Inessa Lokshina, Ryuji Higashikubo, Sarah Evans, Xinping Liu, Adil Hassan, Satona Tanaka, Markus Cicka, Hsi-Min Hsiao, Daniel Ruiz-Perez, Andrea Bredemeyer, Richard W. Gross, Douglas L. Mann, Yulia Y. Tyurina, Andrew E. Gelman, Valerian E. Kagan, Andreas Linkermann, Kory J. Lavine, Daniel Kreisel
×Abstract
Chronic alcohol consumption causes liver injury, inflammation, and fibrosis, thereby increasing morbidity and mortality. Paradoxically, modest drinking is believed to confer metabolic improvement, but the underlying mechanism remains elusive. Here, we have identified a hepatoprotective brain/brown adipose tissue (BAT)/liver axis. Alcohol consumption or direct alcohol administration into the brain stimulated hypothalamic neural circuits and sympathetic nerves innervating BAT and dramatically increased BAT uncoupling protein 1 (Ucp1) expression and activity in a BAT-sympathetic nerve-dependent manner. BAT and beige fat oxidized fatty acids to fuel Ucp1-mediated thermogenesis, thereby inhibiting lipid trafficking into the liver. BAT also secreted several adipokines, including adiponectin, which suppressed hepatocyte injury and death. Genetic deletion of Ucp1 profoundly augmented alcohol-induced liver steatosis, injury, inflammation, and fibrosis in male and female mice. Conversely, activation of BAT and beige fat through cold exposure suppressed alcoholic liver disease development. Our results unravel an unrecognized brain alcohol-sensing/sympathetic nerve/BAT/liver axis that counteracts liver steatosis and injury.
Authors
Hong Shen, Lin Jiang, Jiandie D. Lin, M. Bishr Omary, Liangyou Rui
×Abstract
Mice selectively expressing a PPARγ dominant-negative mutation in vascular smooth muscle exhibit RhoBTB1 deficiency and hypertension. Our rationale was to use genetic complementation to uncover the mechanism of action of RhoBTB1 in vascular smooth muscle. Inducible smooth muscle–specific restoration of RhoBTB1 fully corrected hypertension and arterial stiffness by improving vasodilator function. Notably, the cardiovascular protection occurred despite the preservation of increased agonist-mediated contraction and RhoA and Rho kinase activity, suggesting that RhoBTB1 selectively controls vasodilation. RhoBTB1 augmented the cyclic 3′,5′-monophosphate (cGMP) response to NO by restraining the activity of phosphodiesterase 5 (PDE5) through its action as a substrate adaptor delivering PDE5 to the Cullin-3 E3 ring ubiquitin ligase complex for ubiquitination, thereby inhibiting PDE5. Angiotensin II infusion also caused RhoBTB1 deficiency and hypertension, which were prevented by smooth muscle–specific RhoBTB1 restoration. We conclude that RhoBTB1 protected against hypertension, vascular smooth muscle dysfunction, and arterial stiffness in at least 2 models of hypertension.
Authors
Masashi Mukohda, Shi Fang, Jing Wu, Larry N. Agbor, Anand R. Nair, Stella-Rita C. Ibeawuchi, Chunyan Hu, Xuebo Liu, Ko-Ting Lu, Deng-Fu Guo, Deborah R. Davis, Henry L. Keen, Frederick W. Quelle, Curt D. Sigmund
×Abstract
Hormone therapy (HT) is reported to be deficient in improving learning and memory in older postmenopausal women according to recent clinical studies; however, the reason for failure is unknown. A “window of opportunity” for estrogen treatment is proposed to explain this deficiency. Here, we found that facilitation of memory extinction and long-term depression by 17β-estradiol (E2) was normal in mice 1 week after ovariectomy (OVXST), but it was impaired in mice 3 months after ovariectomy (OVXLT). High-throughput sequencing revealed a decrease of miR-221-5p, which promoted cannabinoid receptor 1 (CB1) ubiquitination by upregulation of Neurl1a/b in E2-treated OVXLT mice. Blood samples from postmenopausal women aged 56–65 indicated decreases of miR-221-5p and 2-arachidonoylglycerol compared with samples from perimenopausal women aged 46–55. Replenishing of miR-221-5p or treatment with a CB1 agonist rescued the impairment of fear extinction in E2-treated OVXLT mice. The present study demonstrates that an HT time window in mice can be prolonged by cotreatment with a CB1 agonist, implying a potential strategy for HT in long-term menopausal women.
Authors
Kun Zhang, Qi Yang, Le Yang, Yan-jiao Li, Xin-shang Wang, Yu-jiao Li, Rui-li Dang, Shao-yu Guan, Yan-yan Guo, Ting Sun, Yu-mei Wu, An Liu, Yan Zhang, Shui-bing Liu, Ming-gao Zhao
×Abstract
BACKGROUND African American patients have higher cancer mortality rates and shorter survival times compared with European American patients. Despite a significant focus on socioeconomic factors, recent findings strongly argue the existence of biological factors driving this disparity. Most of these factors have been described in a cancer-type specific context rather than a pan-cancer setting.METHODS A novel in silico approach based on Gene Set Enrichment Analysis (GSEA) coupled to transcription factor enrichment was carried out to identify common biological drivers of pan-cancer racial disparity using The Cancer Genome Atlas data set. Mitochondrial content in patient tissues was examined using a multi-cancer tissue microarray approach (TMA).RESULTS Mitochondrial oxidative phosphorylation was uniquely enriched in tumors from African American patients compared with tumors of various cancer types from European American patients. Tumors from African American patients also showed strong enrichment for the ERR1-PGC1α–mediated transcriptional program, which has been implicated in mitochondrial biogenesis. TMA analysis revealed that cancers from African American patients harbor significantly more mitochondria compared with the same cancers from European American patients.CONCLUSION These findings highlight changes in mitochondria as a common distinguishing feature among tumors from African American versus European American patients in a pan-cancer setting, and provide the rationale for the repurposing of mitochondrial inhibitors to treat cancers from African American patients.FUNDING This research was partially supported by National Institutes of Health grants NIH U01 CA167234, NIH 1 U01 CA179674-01A1, 5R01GM11402903, 1U01CA23548701, U01 CA167234, R01CA220297, and R01CA216426; pilot and shared resources support from Dan L. Duncan Cancer Center grant P30 CA125123; and NCI SPORE pilot grant NIH P50 CA186784. It was also partially supported by the Diana Helis Henry Medical Research Foundation; the Brockman Foundation; Agilent Technologies; Department of Defense grants W81XWH-12-1-0130 and W81XWH-12-1-0046; Cancer Prevention Research Institute of Texas grant RP120092; a Prostate Cancer Foundation Challenge Award; National Science Foundation grant DMS-1545277; and American Cancer Society grant 127430-RSG-15-105-01-CNE.
Authors
Danthasinghe Waduge Badrajee Piyarathna, Akhila Balasubramanian, James M. Arnold, Stacy M. Lloyd, Balasubramanyam Karanam, Patricia Castro, Michael M. Ittmann, Nagireddy Putluri, Nora Navone, Jeffrey A. Jones, Wendong Yu, Vlad C. Sandulache, Andrew G. Sikora, George Michailidis, Arun Sreekumar
×Abstract
Posttransplantation cyclophosphamide (PTCy) recently has had a marked impact on human allogeneic hematopoietic cell transplantation (HCT). Yet our understanding of how PTCy prevents graft-versus-host disease (GVHD) largely has been extrapolated from MHC-matched murine skin-allografting models that were highly contextual in their efficacy. Herein, we developed a T cell–replete, MHC-haploidentical, murine HCT model (B6C3F1→B6D2F1) to test the putative underlying mechanisms: alloreactive T cell elimination, alloreactive T cell intrathymic clonal deletion, and suppressor T cell induction. In this model and as confirmed in four others, PTCy did not eliminate alloreactive T cells identified using either specific Vβs or the 2C or 4C T cell receptors. Furthermore, the thymus was not necessary for PTCy’s efficacy. Rather, PTCy induced alloreactive T cell functional impairment, which was supported by highly active suppressive mechanisms established within one day after PTCy that were sufficient to prevent new donor T cells from causing GVHD. These suppressive mechanisms included the rapid, preferential recovery of CD4+CD25+Foxp3+ regulatory T cells, including those that were alloantigen specific, which served an increasingly critical function over time. Our results prompt a paradigm shift in our mechanistic understanding of PTCy. These results have direct clinical implications for understanding tolerance induction and for rationally developing novel strategies to improve patient outcomes.
Authors
Lucas P. Wachsmuth, Michael T. Patterson, Michael A. Eckhaus, David J. Venzon, Ronald E. Gress, Christopher G. Kanakry
×Abstract
Acute kidney injury (AKI) can lead to chronic kidney disease (CKD) if injury is severe and/or repair is incomplete. However, the pathogenesis of CKD following renal ischemic injury is not fully understood. Capillary rarefaction and tubular hypoxia are common findings during the AKI-to-CKD transition. We investigated the tubular stress response to hypoxia and demonstrated that a stress-responsive transcription factor, FoxO3, was regulated by prolyl hydroxylase (PHD). Hypoxia inhibited FoxO3 prolyl hydroxylation and FoxO3 degradation, leading to FoxO3 accumulation and activation in tubular cells. Hypoxia-activated HIF-1α contributed to FoxO3 activation and functioned to protect kidneys, as tubular deletion of HIF-1α decreased hypoxia-induced FoxO3 activation and resulted in more severe tubular injury and interstitial fibrosis following ischemic injury. Strikingly, tubular deletion of FoxO3 during the AKI-to-CKD transition aggravated renal structural and functional damage, leading to a much more profound CKD phenotype. We show that tubular deletion of FoxO3 resulted in decreased autophagic response and increased oxidative injury, which may explain renal protection by FoxO3. Our study indicates that in the hypoxic kidney, stress-responsive transcription factors can be activated for adaptions to counteract hypoxic insults, thus attenuating CKD development.
Authors
Ling Li, Huimin Kang, Qing Zhang, Vivette D. D’Agati, Qais Al-Awqati, Fangming Lin
×Abstract
A disintegrine and metalloproteinase 10 (ADAM10) is implicated in synaptic function through its interaction with postsynaptic receptors and adhesion molecules. Here, we report that levels of active ADAM10 are increased in Huntington’s disease (HD) mouse cortices and striata and in human postmortem caudate. We show that, in the presence of polyglutamine-expanded (polyQ-expanded) huntingtin (HTT), ADAM10 accumulates at the postsynaptic densities (PSDs) and causes excessive cleavage of the synaptic protein N-cadherin (N-CAD). This aberrant phenotype is also detected in neurons from HD patients where it can be reverted by selective silencing of mutant HTT. Consistently, ex vivo delivery of an ADAM10 synthetic inhibitor reduces N-CAD proteolysis and corrects electrophysiological alterations in striatal medium-sized spiny neurons (MSNs) of 2 HD mouse models. Moreover, we show that heterozygous conditional deletion of ADAM10 or delivery of a competitive TAT-Pro-ADAM10709–729 peptide in R6/2 mice prevents N-CAD proteolysis and ameliorates cognitive deficits in the mice. Reduction in synapse loss was also found in R6/2 mice conditionally deleted for ADAM10. Taken together, these results point to a detrimental role of hyperactive ADAM10 at the HD synapse and provide preclinical evidence of the therapeutic potential of ADAM10 inhibition in HD.
Authors
Elena Vezzoli, Ilaria Caron, Francesca Talpo, Dario Besusso, Paola Conforti, Elisa Battaglia, Elisa Sogne, Andrea Falqui, Lara Petricca, Margherita Verani, Paola Martufi, Andrea Caricasole, Alberto Bresciani, Ottavia Cecchetti, Pia Rivetti di Val Cervo, Giulio Sancini, Olaf Riess, Hoa Nguyen, Lisa Seipold, Paul Saftig, Gerardo Biella, Elena Cattaneo, Chiara Zuccato
×Abstract
Bariatric surgeries are integral to the management of obesity and its metabolic complications. However, these surgeries cause bone loss and increase fracture risk through poorly understood mechanisms. In a mouse model, vertical sleeve gastrectomy (VSG) caused trabecular and cortical bone loss that was independent of sex, body weight, and diet, and this loss was characterized by impaired osteoid mineralization and bone formation. VSG had a profound effect on the bone marrow niche, with rapid loss of marrow adipose tissue, and expansion of myeloid cellularity, leading to increased circulating neutrophils. Following VSG, circulating granulocyte–colony stimulating factor (G-CSF) was increased in mice, and was transiently elevated in a longitudinal study of humans. Elevation of G-CSF was found to recapitulate many effects of VSG on bone and the marrow niche. In addition to stimulatory effects of G-CSF on myelopoiesis, endogenous G-CSF suppressed development of marrow adipocytes and hindered accrual of peak cortical and trabecular bone. Effects of VSG on induction of neutrophils and depletion of marrow adiposity were reduced in mice deficient for G-CSF; however, bone mass was not influenced. Although not a primary mechanism for bone loss with VSG, G-CSF plays an intermediary role for effects of VSG on the bone marrow niche.
Authors
Ziru Li, Julie Hardij, Simon S. Evers, Chelsea R. Hutch, Sarah M. Choi, Yikai Shao, Brian S. Learman, Kenneth T. Lewis, Rebecca L. Schill, Hiroyuki Mori, Devika P. Bagchi, Steven M. Romanelli, Ki-Suk Kim, Emily Bowers, Cameron Griffin, Randy J. Seeley, Kanakadurga Singer, Darleen A. Sandoval, Clifford J. Rosen, Ormond A. MacDougald
×Abstract
Glial cells have emerged as key players in the central control of energy balance and etiology of obesity. Astrocytes play a central role in neural communication via the release of gliotransmitters. Acyl-CoA–binding protein–derived (ACBP-derived) endozepines are secreted peptides that modulate the GABAA receptor. In the hypothalamus, ACBP is enriched in arcuate nucleus (ARC) astrocytes, ependymocytes, and tanycytes. Central administration of the endozepine octadecaneuropeptide (ODN) reduces feeding and improves glucose tolerance, yet the contribution of endogenous ACBP in energy homeostasis is unknown. We demonstrated that ACBP deletion in GFAP+ astrocytes, but not in Nkx2.1-lineage neural cells, promoted diet-induced hyperphagia and obesity in both male and female mice, an effect prevented by viral rescue of ACBP in ARC astrocytes. ACBP+ astrocytes were observed in apposition with proopiomelanocortin (POMC) neurons, and ODN selectively activated POMC neurons through the ODN GPCR but not GABAA, and suppressed feeding while increasing carbohydrate utilization via the melanocortin system. Similarly, ACBP overexpression in ARC astrocytes reduced feeding and weight gain. Finally, the ODN GPCR agonist decreased feeding and promoted weight loss in ob/ob mice. These findings uncover ACBP as an ARC gliopeptide playing a key role in energy balance control and exerting strong anorectic effects via the central melanocortin system.
Authors
Khalil Bouyakdan, Hugo Martin, Fabienne Liénard, Lionel Budry, Bouchra Taib, Demetra Rodaros, Chloé Chrétien, Éric Biron, Zoé Husson, Daniela Cota, Luc Pénicaud, Stephanie Fulton, Xavier Fioramonti, Thierry Alquier
×Abstract
How altered metabolism contributes to chemotherapy resistance in cancer cells remains unclear. Through a metabolism-related kinome RNAi screen, we identified inositol-trisphosphate 3-kinase B (ITPKB) as a critical enzyme that contributes to cisplatin-resistant tumor growth. We demonstrated that inositol 1,3,4,5-tetrakisphosphate (IP4), the product of ITPKB, plays a critical role in redox homeostasis upon cisplatin exposure by reducing cisplatin-induced ROS through inhibition of a ROS-generating enzyme, NADPH oxidase 4 (NOX4), which promotes cisplatin-resistant tumor growth. Mechanistically, we identified that IP4 competes with the NOX4 cofactor NADPH for binding and consequently inhibits NOX4. Targeting ITPKB with shRNA or its small-molecule inhibitor resulted in attenuation of NOX4 activity, imbalanced redox status, and sensitized cancer cells to cisplatin treatment in patient-derived xenografts. Our findings provide insight into the crosstalk between kinase-mediated metabolic regulation and platinum-based chemotherapy resistance in human cancers. Our study also suggests a distinctive signaling function of IP4 that regulates NOX4. Furthermore, pharmaceutical inhibition of ITPKB displayed synergistic attenuation of tumor growth with cisplatin, suggesting ITPKB as a promising synthetic lethal target for cancer therapeutic intervention to overcome cisplatin resistance.
Authors
Chaoyun Pan, Lingtao Jin, Xu Wang, Yuancheng Li, Jaemoo Chun, Austin C. Boese, Dan Li, Hee-Bum Kang, Guojing Zhang, Lu Zhou, Georgia Z. Chen, Nabil F. Saba, Dong M. Shin, Kelly R. Magliocca, Taofeek K. Owonikoko, Hui Mao, Sagar Lonial, Sumin Kang
×Abstract
We studied human T cell repertoire formation using high-throughput T cell receptor β (TCRβ) complementarity-determining region 3 (CDR3) sequencing in immunodeficient mice receiving human hematopoietic stem cells (HSCs) and human thymus grafts. Replicate humanized mice generated diverse and highly divergent repertoires. We observed repertoire narrowing and increased CDR3β sharing during thymocyte selection. Whereas hydrophobicity analysis implicated self-peptides in positive selection of the overall repertoire, positive selection favored shorter shared sequences that had reduced hydrophobicity at positions 6 and 7 of CDR3βs, suggesting weaker interactions with self-peptides than were observed with unshared sequences, possibly allowing escape from negative selection. Sharing was similar between autologous and allogeneic thymi and occurred between different cell subsets. Shared sequences were enriched for allo–cross-reactive CDR3βs and for type 1 diabetes–associated autoreactive CDR3βs. Single-cell TCR sequencing showed increased sharing of CDR3αs compared with CDR3βs between mice. Our data collectively implicate preferential positive selection for shared human CDR3βs that are highly cross-reactive. Although previous studies suggested a role for recombination bias in producing “public” sequences in mice, our study is the first to our knowledge to demonstrate a role for thymic selection. Our results implicate positive selection for promiscuous TCRβ sequences that probably evade negative selection, given their low affinity for self-ligands, in the abundance of “public” human TCRβ sequences.
Authors
Mohsen Khosravi-Maharlooei, Aleksandar Obradovic, Aditya Misra, Keshav Motwani, Markus Holzl, Howard R. Seay, Susan DeWolf, Grace Nauman, Nichole Danzl, Haowei Li, Siu-hong Ho, Robert Winchester, Yufeng Shen, Todd M. Brusko, Megan Sykes
×Abstract
Tumor-infiltrating lymphocytes (TILs) are widely associated with positive outcomes, yet carry key indicators of a systemic failed immune response against unresolved cancer. Cancer immunotherapies can reverse their tolerance phenotypes while preserving tumor reactivity and neoantigen specificity shared with circulating immune cells. We performed comprehensive transcriptomic analyses to identify gene signatures common to circulating and TILs in the context of clear cell renal cell carcinoma. Modulated genes also associated with disease outcome were validated in other cancer types. Through comprehensive bioinformatics analyses, we identified practical diagnostic markers and actionable targets of the failed immune response. On circulating lymphocytes, 3 genes (LEF1, FASLG, and MMP9) could efficiently stratify patients from healthy control donors. From their associations with resistance to cancer immunotherapies and microbial infections, we uncovered not only pan-cancer, but pan-pathology, failed immune response profiles. A prominent lymphocytic matrix metallopeptidase cell migration pathway is central to a panoply of diseases and tumor immunogenicity, correlates with multi-cancer recurrence, and identifies a feasible noninvasive approach to pan-pathology diagnoses. The differentially expressed genes we have identified warrant future investigation into the development of their potential in noninvasive precision diagnostics and precision pan-disease immunotherapeutics.
Authors
Anne Monette, Antigoni Morou, Nadia A. Al-Banna, Louise Rousseau, Jean-Baptiste Lattouf, Sara Rahmati, Tomas Tokar, Jean-Pierre Routy, Jean-François Cailhier, Daniel E. Kaufmann, Igor Jurisica, Réjean Lapointe
×Abstract
Opioid use disorder is associated with the emergence of persistent negative emotional states during drug abstinence that drive compulsive drug taking and seeking. Functional magnetic resonance imaging (fMRI) in rats identified neurocircuits that were activated by stimuli that were previously paired with heroin withdrawal. The activation of amygdala and hypothalamic circuits was related to the degree of heroin dependence, supporting the significance of conditioned negative affect in sustaining compulsive-like heroin seeking and taking and providing neurobiological insights into the drivers of the current opioid crisis.
Authors
Stephanie A. Carmack, Robin J. Keeley, Janaina C. M. Vendruscolo, Emily G. Lowery-Gionta, Hanbing Lu, George F. Koob, Elliot A. Stein, Leandro F. Vendruscolo
×Abstract
Prevalence of obesity among infants and children below 5 years of age is rising dramatically, and early childhood obesity is a forerunner of obesity and obesity-associated diseases in adulthood. Childhood obesity is hence one of the most serious public health challenges today. Here, we have identified a mother-to-child lipid signaling that protects from obesity. We have found that breast milk–specific lipid species, so-called alkylglycerol-type (AKG-type) ether lipids, which are absent from infant formula and adult-type diets, maintain beige adipose tissue (BeAT) in the infant and impede the transformation of BeAT into lipid-storing white adipose tissue (WAT). Breast milk AKGs are metabolized by adipose tissue macrophages (ATMs) to platelet-activating factor (PAF), which ultimately activates IL-6/STAT3 signaling in adipocytes and triggers BeAT development in the infant. Accordingly, lack of AKG intake in infancy leads to a premature loss of BeAT and increases fat accumulation. AKG signaling is specific for infants and is inactivated in adulthood. However, in obese adipose tissue, ATMs regain their ability to metabolize AKGs, which reduces obesity. In summary, AKGs are specific lipid signals of breast milk that are essential for healthy adipose tissue development.
Authors
Haidong Yu, Sedat Dilbaz, Jonas Coßmann, Anh Cuong Hoang, Victoria Diedrich, Annika Herwig, Akiko Harauma, Yukino Hoshi, Toru Moriguchi, Kathrin Landgraf, Antje Körner, Christina Lucas, Susanne Brodesser, Lajos Balogh, Julianna Thuróczy, Gopal Karemore, Michael Scott Kuefner, Edwards A. Park, Christine Rapp, Jeffrey Bryant Travers, Tamás Röszer
×Ligand-based design identifies a potent NUPR1 inhibitor exerting anticancer activity via necroptosis
Abstract
Intrinsically disordered proteins (IDPs) are emerging as attractive drug targets by virtue of their prevalence in various diseases including cancer. Drug development targeting IDPs is challenging because IDPs have dynamic structure features and conventional drug design is not applicable. NUPR1 is an IDP that plays an important role in pancreatic cancer. We previously reported that trifluoperazine (TFP), an antipsychotic agent, was capable of binding to NUPR1 and inhibiting tumor growth. Unfortunately, TFP showed strong central nervous system side effects. In the present work, we undertook a multidisciplinary approach to optimize TFP based on the synergy of computer modeling, chemical synthesis, and a variety of biophysical, biochemical, and biological evaluations. A family of TFP-derived compounds was produced and the most active one, ZZW-115, showed a dose-dependent tumor regression with no neurological effects and an ability to induce cell death mainly by necroptosis. This study opens a new perspective for drug development against IDPs, demonstrating the possibility of successful ligand-based drug design for such challenging targets.
Authors
Patricia Santofimia-Castaño, Yi Xia, Wenjun Lan, Zhengwei Zhou, Can Huang, Ling Peng, Philippe Soubeyran, Adrián Velázquez-Campoy, Olga Abián, Bruno Rizzuti, José L. Neira, Juan Iovanna
×Abstract
The lung is a specialized barrier organ that must tightly regulate interstitial fluid clearance and prevent infection in order to maintain effective gas exchange. Lymphatic vessels are important for these functions in other organs, but their roles in the lung have not been fully defined. In the present study, we evaluated how the lymphatic vasculature participates in lung homeostasis. Studies using mice carrying a lymphatic reporter allele revealed that, in contrast to other organs, lung lymphatic collecting vessels lack smooth muscle cells entirely, suggesting that forward lymph flow is highly dependent on movement and changes in pressure associated with respiration. Functional studies using C-type lectin domain family 2–deficient (CLEC2-deficient) mice in which lymph flow is impaired because of loss of lympho-venous hemostasis, or using inducible lung-specific ablation of lymphatic endothelial cells in a lung transplant model revealed that loss of lymphatic function leads to an inflammatory state characterized by the formation of tertiary lymphoid organs (TLOs). In addition, impaired lymphatic flow in mice resulted in hypoxia and features of lung injury that resembled emphysema. These findings reveal both a lung-specific mechanism of lymphatic physiology and a lung-specific consequence of lymphatic dysfunction that may contribute to chronic lung diseases that arise in association with TLO formation.
Authors
Hasina Outtz Reed, Liqing Wang, Jarrod Sonett, Mei Chen, Jisheng Yang, Larry Li, Petra Aradi, Zoltan Jakus, Jeanine D’Armiento, Wayne W. Hancock, Mark L. Kahn
×Protein tyrosine phosphatase non-receptor type 22 modulates colitis in a microbiota-dependent manner
Abstract
The gut microbiota is crucial for our health, and well-balanced interactions between the host’s immune system and the microbiota are essential to prevent chronic intestinal inflammation, as observed in inflammatory bowel diseases (IBD). A variant in protein tyrosine phosphatase non-receptor type 22 (PTPN22) is associated with reduced risk of developing IBD, but promotes the onset of autoimmune disorders. While the role of PTPN22 in modulating molecular pathways involved in IBD pathogenesis is well studied, its impact on shaping the intestinal microbiota has not been addressed in depth. Here, we demonstrate that mice carrying the PTPN22 variant (619W mice) were protected from acute dextran sulfate sodium (DSS) colitis, but suffered from pronounced inflammation upon chronic DSS treatment. The basal microbiota composition was distinct between genotypes, and DSS-induced dysbiosis was milder in 619W mice than in WT littermates. Transfer of microbiota from 619W mice after the first DSS cycle into treatment-naive 619W mice promoted colitis, indicating that changes in microbial composition enhanced chronic colitis in those animals. This indicates that presence of the PTPN22 variant affects intestinal inflammation by modulating the host’s response to the intestinal microbiota.
Authors
Marianne R. Spalinger, Thomas S.B. Schmidt, Marlene Schwarzfischer, Larissa Hering, Kirstin Atrott, Silvia Lang, Claudia Gottier, Annelies Geirnaert, Christophe Lacroix, Xuezhi Dai, David J. Rawlings, Andrew C. Chan, Christian von Mering, Gerhard Rogler, Michael Scharl
×Abstract
Preclinical studies demonstrate that rapid-acting antidepressants, including ketamine, require stimulation of mTORC1 signaling. This pathway is regulated by neuronal activity and endocrine and metabolic signals, notably including the amino acid leucine, which activates mTORC1 signaling via binding to the upstream regulator sestrin. Here, we examined the antidepressant actions of NV-5138, a highly selective small molecule modulator of sestrin that penetrates the blood-brain barrier. The results demonstrate that a single dose of NV-5138 produced rapid and long-lasting antidepressant effects and rapidly reversed anhedonia caused by chronic stress exposure. The antidepressant actions of NV-5138 required brain-derived neurotrophic factor (BDNF) release, as the behavioral responses were blocked by infusion of a BDNF-neutralizing Ab into the medial prefrontal cortex (mPFC) or, in mice, with a knockin of a BDNF polymorphism that blocked activity-dependent BDNF release. NV-5138 administration also rapidly increased synapse number and function in the mPFC and reversed the synaptic deficits caused by chronic stress. Together, the results demonstrate that NV-5138 produces rapid synaptic and antidepressant behavioral responses via activation of the mTORC1 pathway and BDNF signaling, indicating that pharmacological modulation of sestrin may be an attractive approach for the development of rapid-acting antidepressants.
Authors
Taro Kato, Santosh Pothula, Rong-Jian Liu, Catharine H. Duman, Rosemarie Terwilliger, George P. Vlasuk, Eddine Saiah, Seung Hahm, Ronald S. Duman
×Abstract
The nuclear protein DEK is an endogenous DNA-binding chromatin factor regulating hematopoiesis. DEK is one of only 2 known secreted nuclear chromatin factors, but whether and how extracellular DEK regulates hematopoiesis is not known. We demonstrated that extracellular DEK greatly enhanced ex vivo expansion of cytokine-stimulated human and mouse hematopoietic stem cells (HSCs) and regulated HSC and hematopoietic progenitor cell (HPC) numbers in vivo and in vitro as determined both phenotypically (by flow cytometry) and functionally (through transplantation and colony formation assays). Recombinant DEK increased long-term HSC numbers and decreased HPC numbers through a mechanism mediated by the CXC chemokine receptor CXCR2 and heparan sulfate proteoglycans (HSPGs) (as determined utilizing Cxcr2–/– mice, blocking CXCR2 antibodies, and 3 different HSPG inhibitors) that was associated with enhanced phosphorylation of ERK1/2, AKT, and p38 MAPK. To determine whether extracellular DEK required nuclear function to regulate hematopoiesis, we utilized 2 mutant forms of DEK: one that lacked its nuclear translocation signal and one that lacked DNA-binding ability. Both altered HSC and HPC numbers in vivo or in vitro, suggesting the nuclear function of DEK is not required. Thus, DEK acts as a hematopoietic cytokine, with the potential for clinical applicability.
Authors
Maegan L. Capitano, Nirit Mor-Vaknin, Anjan K. Saha, Scott Cooper, Maureen Legendre, Haihong Guo, Rafael Contreras-Galindo, Ferdinand Kappes, Maureen A. Sartor, Christopher T. Lee, Xinxin Huang, David M. Markovitz, Hal E. Broxmeyer
×Abstract
Increased urinary oxalate excretion (hyperoxaluria) promotes the formation of calcium oxalate crystals. Monogenic diseases due to hepatic enzyme deficiency result in chronic hyperoxaluria, promoting end-stage renal disease in children and young adults. Ethylene glycol poisoning also results in hyperoxaluria, promoting acute renal failure and frequently death. Stiripentol is an antiepileptic drug used to treat children affected by Dravet syndrome. It has been shown to inhibit neuronal lactate dehydrogenase 5 enzyme. As this isoenzyme is also the last step of hepatic oxalate production, we hypothesized that stiripentol would potentially reduce hepatic oxalate production and urine oxalate excretion. In vitro, stiripentol decreased the synthesis of oxalate by hepatocytes in a dose-dependent manner. In vivo, oral administration of stiripentol significantly reduced urine oxalate excretion in rats. Stiripentol protected the kidneys against calcium oxalate crystal deposits in acute ethylene glycol intoxication and chronic calcium oxalate nephropathy models. In both models, stiripentol significantly improved renal function. Patients affected by Dravet syndrome and treated with stiripentol had a lower urine oxalate excretion than control patients. A young girl affected by severe type I hyperoxaluria received stiripentol for several weeks, and urine oxalate excretion decreased by two-thirds. Stiripentol is a promising potential therapy against genetic hyperoxaluria and ethylene glycol poisoning.
Authors
Marine Le Dudal, Léa Huguet, Joëlle Perez, Sophie Vandermeersch, Elise Bouderlique, Ellie Tang, Carole Martori, Nicole Chemaly, Rima Nabbout, Jean-Philippe Haymann, Vincent Frochot, Laurent Baud, Georges Deschênes, Michel Daudon, Emmanuel Letavernier
×Abstract
Cortical bones account for more than 80% of human bone mass. The periosteum, a thin tissue that covers almost the entire bone surface, is essential for bone formation and regeneration. However, its osteogenic and bone regenerative abilities are not well studied. In this study, we found that macrophage-lineage cells recruit periosteum-derived cells (PDCs) for cortical bone formation. Knockout of colony-stimulating factor-1 eliminated macrophage-lineage cells and resulted in loss of PDCs with impaired periosteal bone formation. Moreover, macrophage-lineage tartrate-resistant acid phosphatase–positive (TRAP+) cells induced transcriptional expression of periostin and recruitment of PDCs to the periosteal surface through secretion of PDGF-BB, where the recruited PDCs underwent osteoblast differentiation coupled with type H vessel formation. We also found that subsets of Nestin+ and LepR+CD45–Ter119–CD31– cells (LepR+ PDCs) possess multipotent and self-renewal abilities and contribute to cortical bone formation. Nestin+ PDCs are found primarily during bone development, whereas LepR+ PDCs are essential for bone homeostasis in adult mice. Importantly, conditional knockout of Pdgfr-β in LepR+ cells impaired periosteal bone formation and regeneration. These findings uncover the essential role of periosteal macrophage-lineage cells in regulating periosteum homeostasis and regeneration.
Authors
Bo Gao, Ruoxian Deng, Yu Chai, Hao Chen, Bo Hu, Xiao Wang, Shouan Zhu, Yong Cao, Shuangfei Ni, Mei Wan, Liu Yang, Zhuojing Luo, Xu Cao
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)