In this issue of JCI Insight, Xiang et al. investigate the role of human T cell leukemia virus type 1 (HTLV-1) oncogenes in driving bone loss in adult T cell leukemia/lymphoma. They find that the viral oncogene HBZ played only a minor role in the lymphoproliferative disorder, but was required for disease-induced bone loss. The cover image shows tartrate-resistant acid phosphatase (TRAP, pink) staining of osteoclasts in the tibia of a humanized mouse infected with HTLV-1 lacking HBZ.
Immune checkpoint blockade has revolutionized cancer treatment. Patients developing immune mediated adverse events, such as colitis, appear to particularly benefit from immune checkpoint inhibition. Yet, the contributing mechanisms are largely unknown. We identified a systemic LPS signature in melanoma patients with colitis following anti–cytotoxic T lymphocyte–associated antigen 4 (anti–CTLA-4) checkpoint inhibitor treatment and hypothesized that intestinal microbiota–derived LPS contributes to therapeutic efficacy. Because activation of immune cells within the tumor microenvironment is considered most promising to effectively control cancer, we analyzed human and murine melanoma for known sentinels of LPS. We identified mast cells (MCs) accumulating in and around melanomas and showed that effective melanoma immune control was dependent on LPS-activated MCs recruiting tumor-infiltrating effector T cells by secretion of CXCL10. Importantly, CXCL10 was also upregulated in human melanomas with immune regression and in patients with colitis induced by anti–CTLA-4 antibody. Furthermore, we demonstrate that CXCL10 upregulation and an MC signature at the site of melanomas are biomarkers for better patient survival. These findings provide conclusive evidence for a “Trojan horse treatment strategy” in which the plasticity of cancer-resident immune cells, such as MCs, is used as a target to boost tumor immune defense.
Susanne Kaesler, Florian Wölbing, Wolfgang Eberhard Kempf, Yuliya Skabytska, Martin Köberle, Thomas Volz, Tobias Sinnberg, Teresa Amaral, Sigrid Möckel, Amir Yazdi, Gisela Metzler, Martin Schaller, Karin Hartmann, Benjamin Weide, Claus Garbe, Hans-Georg Rammensee, Martin Röcken, Tilo Biedermann
Perturbations in biomechanical stimuli during cardiac development contribute to congenital cardiac defects such as hypoplastic left heart syndrome (HLHS). This study sought to identify stretch-responsive pathways involved in cardiac development. miRNA-Seq identified miR-486 as being increased in cardiomyocytes exposed to cyclic stretch in vitro. The right ventricles (RVs) of patients with HLHS experienced increased stretch and had a trend toward higher miR-486 levels. Sheep RVs dilated from excessive pulmonary blood flow had 60% more miR-486 compared with control RVs. The left ventricles of newborn mice treated with miR-486 mimic were 16.9%–24.6% larger and displayed a 2.48-fold increase in cardiomyocyte proliferation. miR-486 treatment decreased FoxO1 and Smad signaling while increasing the protein levels of Stat1. Stat1 associated with Gata-4 and serum response factor (Srf), 2 key cardiac transcription factors with protein levels that increase in response to miR-486. This is the first report to our knowledge of a stretch-responsive miRNA that increases the growth of the ventricle in vivo.
Stephan Lange, Indroneal Banerjee, Katrina Carrion, Ricardo Serrano, Louisa Habich, Rebecca Kameny, Luisa Lengenfelder, Nancy Dalton, Rudolph Meili, Emma Börgeson, Kirk Peterson, Marco Ricci, Joy Lincoln, Majid Ghassemian, Jeffery Fineman, Juan C. del Álamo, Vishal Nigam
Aberrant accumulation and activation of eosinophils and potentially mast cells (MCs) contribute to the pathogenesis of eosinophilic gastrointestinal diseases (EGIDs), including eosinophilic esophagitis (EoE), gastritis (EG), and gastroenteritis (EGE). Current treatment options, such as diet restriction and corticosteroids, have limited efficacy and are often inappropriate for chronic use. One promising new approach is to deplete eosinophils and inhibit MCs with a monoclonal antibody (mAb) against sialic acid–binding immunoglobulin-like lectin 8 (Siglec-8), an inhibitory receptor selectively expressed on MCs and eosinophils. Here, we characterize MCs and eosinophils from human EG and EoE biopsies using flow cytometry and evaluate the effects of an anti–Siglec-8 mAb using a potentially novel Siglec-8–transgenic mouse model in which EG/EGE was induced by ovalbumin sensitization and intragastric challenge. MCs and eosinophils were significantly increased and activated in human EG and EoE biopsies compared with healthy controls. Similar observations were made in EG/EGE mice. In Siglec-8–transgenic mice, anti–Siglec-8 mAb administration significantly reduced eosinophils and MCs in the stomach, small intestine, and mesenteric lymph nodes and decreased levels of inflammatory mediators. In summary, these findings suggest a role for both MCs and eosinophils in EGID pathogenesis and support the evaluation of anti–Siglec-8 as a therapeutic approach that targets both eosinophils and MCs.
Bradford A. Youngblood, Emily C. Brock, John Leung, Rustom Falahati, Bruce S. Bochner, Henrik S. Rasmussen, Kathryn Peterson, Christopher Bebbington, Nenad Tomasevic
Oxidative stress is a major contributor to chronic lung diseases. Antioxidants such as N-acetylcysteine (NAC) are broadly viewed as protective molecules that prevent the mutagenic effects of reactive oxygen species. Antioxidants may, however, increase the risk of some forms of cancer and accelerate lung cancer progression in murine models. Here, we investigated chronic NAC treatment in aging mice displaying lung oxidative stress and cell senescence due to inactivation of the transcription factor JunD, which is downregulated in diseased human lungs. NAC treatment decreased lung oxidative damage and cell senescence and protected from lung emphysema but concomitantly induced the development of lung adenocarcinoma in 50% of JunD-deficient mice and 10% of aged control mice. This finding constitutes the first evidence to our knowledge of a carcinogenic effect of antioxidant therapy in the lungs of aged mice with chronic lung oxidative stress and warrants the utmost caution when considering the therapeutic use of antioxidants.
Marielle Breau, Amal Houssaini, Larissa Lipskaia, Shariq Abid, Emmanuelle Born, Elisabeth Marcos, Gabor Czibik, Aya Attwe, Delphine Beaulieu, Alberta Palazzo, Jean-Michel Flaman, Brigitte Bourachot, Guillaume Collin, Jeanne Tran Van Nhieu, David Bernard, Fatima Mechta-Grigoriou, Serge Adnot
B7-H4 is a negative regulatory B7 family member. We investigated the role of host and donor B7-H4 in regulating acute graft-versus-host disease (GVHD). Allogeneic donor T cells infused into B7-H4–/– versus WT recipients markedly accelerated GVHD-induced lethality. Chimera studies pointed toward B7-H4 expression on host hematopoietic cells as more critical than parenchymal cells in controlling GVHD. Rapid mortality in B7-H4–/– recipients was associated with increased donor T cell expansion, gut T cell homing and loss of intestinal epithelial integrity, increased T effector function (proliferation, proinflammatory cytokines, cytolytic molecules), and reduced apoptosis. Higher metabolic demands of rapidly proliferating donor T cells in B7-H4–/– versus WT recipients required multiple metabolic pathways, increased extracellular acidification rates (ECARs) and oxygen consumption rates (OCRs), and increased expression of fuel substrate transporters. During GVHD, B7-H4 expression was upregulated on allogeneic WT donor T cells. B7-H4–/– donor T cells given to WT recipients increased GVHD mortality and had function and biological properties similar to WT T cells from allogeneic B7-H4–/– recipients. Graft-versus-leukemia responses were intact regardless as to whether B7-H4–/– mice were used as hosts or donors. Taken together, these data provide new insights into the negative regulatory processes that control GVHD and provide support for developing therapeutic strategies directed toward the B7-H4 pathway.
Asim Saha, Patricia A. Taylor, Christopher J. Lees, Angela Panoskaltsis-Mortari, Mark J. Osborn, Colby J. Feser, Govindarajan Thangavelu, Wolfgang Melchinger, Yosef Refaeli, Geoffrey R. Hill, David H. Munn, William J. Murphy, Jonathan S. Serody, Ivan Maillard, Katharina Kreymborg, Marcel van den Brink, Chen Dong, Shuyu Huang, Xingxing Zang, James P. Allison, Robert Zeiser, Bruce R. Blazar
Previous studies have demonstrated the presence of microbial DNA in the fetal environment. However, it remains unclear whether this DNA represents viable bacteria and how it relates to the maternal microbiota across body sites. We studied the microbiota of human and mouse dyads to understand these relationships, localize bacteria in the fetus, and demonstrate bacterial viability. In human preterm and full-term mother-infant dyads at the time of cesarean delivery, the oral cavity and meconium of newborn infants born as early as 24 weeks of gestation contained a microbiota that was predicted to originate from in utero sources, including the placenta. Using operative deliveries of pregnant mice under highly controlled, sterile conditions in the laboratory, composition, visualization, and viability of bacteria in the in utero compartment and fetal intestine were demonstrated by 16S rRNA gene sequencing, fluorescence in situ hybridization, and bacterial culture. The composition and predicted source of the fetal gut microbiota shifted between mid- and late gestation. Cultivatable bacteria in the fetal intestine were found during mid-gestation but not late gestation. Our results demonstrate a dynamic, viable mammalian fetal microbiota during in utero development.
Noelle Younge, Jessica R. McCann, Julie Ballard, Catherine Plunkett, Suhail Akhtar, Félix Araújo-Pérez, Amy Murtha, Debra Brandon, Patrick C. Seed
Excessive vascular remodeling is characteristic of hemophilic arthropathy (HA) and may contribute to joint bleeding and the progression of HA. Mechanisms for pathological vascular remodeling after hemophilic joint bleeding are unknown. In hemophilia, activation of thrombin-activatable fibrinolysis inhibitor (TAFI) is impaired, which contributes to joint bleeding and may also underlie the aberrant vascular remodeling. Here, hemophilia A (factor VIII–deficient; FVIII-deficient) mice or TAFI-deficient mice with transient (antibody-induced) hemophilia A were used to determine the role of FVIII and TAFI in vascular remodeling after joint bleeding. Excessive vascular remodeling and vessel enlargement persisted in FVIII-deficient and TAFI-deficient mice, but not in transient hemophilia WT mice, after similar joint bleeding. TAFI-overexpression in FVIII-deficient mice prevented abnormal vessel enlargement and vascular leakage. Age-related vascular changes were observed with FVIII or TAFI deficiency and correlated positively with bleeding severity after injury, supporting increased vascularity as a major contributor to joint bleeding. Antibody-mediated inhibition of uPA also prevented abnormal vascular remodeling, suggesting that TAFI’s protective effects include inhibition of uPA-mediated plasminogen activation. In conclusion, the functional TAFI deficiency in hemophilia drives maladaptive vascular remodeling in the joints after bleeding. These mechanistic insights allow targeted development of potentially new strategies to normalize vascularity and control rebleeding in HA.
Tine Wyseure, Tingyi Yang, Jenny Y. Zhou, Esther J. Cooke, Bettina Wanko, Merissa Olmer, Ruchi Agashe, Yosuke Morodomi, Niels Behrendt, Martin Lotz, John Morser, Annette von Drygalski, Laurent O. Mosnier
Osteolytic bone lesions and hypercalcemia are common, serious complications in adult T cell leukemia/lymphoma (ATL), an aggressive T cell malignancy associated with human T cell leukemia virus type 1 (HTLV-1) infection. The HTLV-1 viral oncogene HBZ has been implicated in ATL tumorigenesis and bone loss. In this study, we evaluated the role of HBZ on ATL-associated bone destruction using HTLV-1 infection and disease progression mouse models. Humanized mice infected with HTLV-1 developed lymphoproliferative disease and continuous, progressive osteolytic bone lesions. HTLV-1 lacking HBZ displayed only modest delays to lymphoproliferative disease but significantly decreased disease-associated bone loss compared with HTLV-1–infected mice. Gene expression array of acute ATL patient samples demonstrated increased expression of RANKL, a critical regulator of osteoclasts. We found that HBZ regulated RANKL in a c-Fos–dependent manner. Treatment of HTLV-1–infected humanized mice with denosumab, a monoclonal antibody against human RANKL, alleviated bone loss. Using patient-derived xenografts from primary human ATL cells to induce lymphoproliferative disease, we also observed profound tumor-induced bone destruction and increased c-Fos and RANKL gene expression. Together, these data show the critical role of HBZ in driving ATL-associated bone loss through RANKL and identify denosumab as a potential treatment to prevent bone complications in ATL patients.
Jingyu Xiang, Daniel A. Rauch, Devra D. Huey, Amanda R. Panfil, Xiaogang Cheng, Alison K. Esser, Xinming Su, John C. Harding, Yalin Xu, Gregory C. Fox, Francesca Fontana, Takayuki Kobayashi, Junyi Su, Hemalatha Sundaramoorthi, Wing Hing Wong, Yizhen Jia, Thomas J. Rosol, Deborah J. Veis, Patrick L. Green, Stefan Niewiesk, Lee Ratner, Katherine N. Weilbaecher
Alcohol withdrawal (AW) after chronic alcohol exposure produces a series of symptoms, with AW-associated seizures being among the most serious and dangerous. However, the mechanism underlying AW seizures has yet to be established. In our mouse model, a sudden AW produced 2 waves of seizures: the first wave includes a surge of multiple seizures that occurs within hours to days of AW, and the second wave consists of sustained expression of epileptiform spikes and wave discharges (SWDs) during a protracted period of abstinence. We revealed that the structural and functional adaptations in newborn dentate granule cells (DGCs) in the hippocampus underlie the second wave of seizures but not the first wave. While the general morphology of newborn DGCs remained unchanged, AW increased the dendritic spine density of newborn DGCs, suggesting that AW induced synaptic connectivity of newborn DGCs with excitatory afferent neurons and enhanced excitability of newborn DGCs. Indeed, specific activation and suppression of newborn DGCs by the chemogenetic DREADD method increased and decreased the expression of epileptiform SWDs, respectively, during abstinence. Thus, our study unveiled that the pathological plasticity of hippocampal newborn DGCs underlies AW seizures during a protracted period of abstinence, providing critical insight into hippocampal neural circuits as a foundation to understand and treat AW seizures.
Daehoon Lee, Balu Krishnan, Hai Zhang, Hee Ra Park, Eun Jeoung Ro, Yu-Na Jung, Hoonkyo Suh
Dysregulated proinflammatory cytokine release has been implicated in the pathogenesis of several life-threatening acute lung illnesses such as pneumonia, sepsis, and acute respiratory distress syndrome. Suppressors of cytokine signaling proteins, particularly SOCS2, have recently been described as antiinflammatory mediators. However, the regulation of SOCS2 protein has not been described. Here we describe a mechanism of SOCS2 regulation by the action of the ubiquitin E3 ligase KIAA0317. KIAA0317-mediated degradation of SOCS2 exacerbated inflammation in vitro, and depletion of KIAA0317 in vivo ameliorated pulmonary inflammation. KIAA0317-knockout mice exhibited resistance to LPS-induced pulmonary inflammation, while KIAA03017 reexpression mitigated this effect. We uncovered a small molecule inhibitor of KIAA0317 protein (BC-1365) that prevented SOCS2 degradation and attenuated LPS- and P. aeruginosa–induced lung inflammation in vivo. These studies show KIAA0317 to be a critical mediator of pulmonary inflammation through its degradation of SOCS2 and a potential candidate target for therapeutic inhibition.
Travis B. Lear, Alison C. McKelvey, John W. Evankovich, Shristi Rajbhandari, Tiffany A. Coon, Sarah R. Dunn, James D. Londino, Bryan J. McVerry, Yingze Zhang, Eleanor Valenzi, Christine L. Burton, Rachael Gordon, Sebastien Gingras, Karina C. Lockwood, Michael J. Jurczak, Robert Lafyatis, Mark J. Shlomchik, Yuan Liu, Bill B. Chen
Nitric oxide regulates BP by binding the reduced heme iron (Fe2+) in soluble guanylyl cyclase (sGC) and relaxing vascular smooth muscle cells (SMCs). We previously showed that sGC heme iron reduction (Fe3+ → Fe2+) is modulated by cytochrome b5 reductase 3 (CYB5R3). However, the in vivo role of SMC CYB5R3 in BP regulation remains elusive. Here, we generated conditional smooth muscle cell–specific Cyb5r3 KO mice (SMC CYB5R3–KO) to test if SMC CYB5R3 loss affects systemic BP in normotension and hypertension via regulation of the sGC redox state. SMC CYB5R3–KO mice exhibited a 5.84-mmHg increase in BP and impaired acetylcholine-induced vasodilation in mesenteric arteries compared with controls. To drive sGC oxidation and elevate BP, we infused mice with angiotensin II. We found that SMC CYB5R3–KO mice exhibited a 14.75-mmHg BP increase, and mesenteric arteries had diminished nitric oxide–dependent vasodilation but increased responsiveness to sGC heme-independent activator BAY 58-2667 over controls. Furthermore, acute injection of BAY 58-2667 in angiotensin II–treated SMC CYB5R3–KO mice showed greater BP reduction compared with controls. Together, these data provide the first in vivo evidence to our knowledge that SMC CYB5R3 is an sGC heme reductase in resistance arteries and provides resilience against systemic hypertension development.
Brittany G. Durgin, Scott A. Hahn, Heidi M. Schmidt, Megan P. Miller, Neha Hafeez, Ilka Mathar, Daniel Freitag, Peter Sandner, Adam C. Straub
Clinical trials of high-dose androgen (HDA) therapy for prostate cancer (PC) have shown promising efficacy but are limited by lack of criteria to identify likely responders. To elucidate factors that govern the growth-repressive effects of HDAs, we applied an unbiased integrative approach using genetic screens and transcriptional profiling of PC cells with or without demonstrated phenotypic sensitivity to androgen-mediated growth repression. Through this comprehensive analysis, we identified genetic events and related signaling networks that determine the response to both HDA and androgen withdrawal. We applied these findings to develop a gene signature that may serve as an early indicator of treatment response and identify men with tumors that are amenable to HDA therapy.
Michael D. Nyquist, Alexandra Corella, Osama Mohamad, Ilsa Coleman, Arja Kaipainen, Daniel A. Kuppers, Jared M. Lucas, Patrick J. Paddison, Stephen R. Plymate, Peter S. Nelson, Elahe A. Mostaghel
CD8+ tumor-infiltrating lymphocytes (TILs) correlate with relapse-free survival (RFS) in most cancer types, including breast cancer. However, subset composition, functional status, and spatial location of CD8+ TILs in relation to RFS in human breast tumors remain unclear. Spatial tissue analysis via quantitative immunofluorescence showed that infiltration of CD8+ T cells into cancer islands was more significantly associated with RFS than CD8+ T cell infiltration into either tumor stroma or total tumor. Localization into cancer islands within tumors is mediated by expression of the integrin CD103, which is a marker for tissue-resident memory T cells (TRMs). Analysis of fresh tumor samples revealed that CD8+ TRMs are functionally similar to other CD8+ TILs, suggesting that the basis of their protective effect is their spatial distribution rather than functional differences. Indeed, CD103+ TRMs, as compared with CD103–CD8+ TILs, are enriched within cancer islands, and CD8+ TRM proximity to cancer cells drives the association of CD8+ TIL densities with RFS. Together, these findings reveal the importance of cancer island–localized CD8+ TRMs in surveillance of the breast tumor microenvironment and as a critical determinant of RFS in patients with breast cancer.
Colt A. Egelston, Christian Avalos, Travis Y. Tu, Anthony Rosario, Roger Wang, Shawn Solomon, Gayathri Srinivasan, Michael S. Nelson, Yinghui Huang, Min Hui Lim, Diana L. Simons, Ting-Fang He, John H. Yim, Laura Kruper, Joanne Mortimer, Susan Yost, Weihua Guo, Christopher Ruel, Paul H. Frankel, Yuan Yuan, Peter P. Lee
We hypothesized that HIV-1 with dual-class but not single-class drug resistance mutations linked on the same viral genome, present in the virus population before initiation of antiretroviral therapy (ART), would be associated with failure of ART to suppress viremia. To test this hypothesis, we utilized an ultrasensitive single-genome sequencing assay that detects rare HIV-1 variants with linked drug resistance mutations (DRMs). A case (ART failure) control (nonfailure) study was designed to assess whether linkage of DRMs in pre-ART plasma samples was associated with treatment outcome in the nevirapine/tenofovir/emtricitabine arm of the AIDS Clinical Trials Group A5208/Optimal Combined Therapy After Nevirapine Exposure (OCTANE) Trial 1 among women who had received prior single-dose nevirapine. Ultrasensitive single-genome sequencing revealed a significant association between pre-ART HIV variants with DRMs to 2 drug classes linked on the same genome (dual class) and failure of combination ART with 3 drugs to suppress viremia. In contrast, linked, single-class DRMs were not associated with ART failure. We conclude that linked dual-class DRMs present before the initiation of ART are associated with ART failure, whereas linked single-class DRMs are not.
Valerie F. Boltz, Wei Shao, Michael J. Bale, Elias K. Halvas, Brian Luke, James A. McIntyre, Robert T. Schooley, Shahin Lockman, Judith S. Currier, Fred Sawe, Evelyn Hogg, Michael D. Hughes, Mary F. Kearney, John M. Coffin, John W. Mellors
BACKGROUND Recessive dystrophic epidermolysis bullosa (RDEB) patients have mutations in the COL7A1 gene and thus lack functional type VII collagen (C7) protein; they have marked skin fragility and blistering. This single-center phase 1/2a open-label study evaluated the long-term efficacy, safety, and patient-reported outcomes in RDEB patients treated with gene-corrected autologous cell therapy.METHODS Autologous keratinocytes were isolated from participant skin biopsies. Epidermal sheets were prepared from cells transduced with a retrovirus carrying the full-length human COL7A1 gene. These gene-corrected autologous epidermal sheets measured 5 × 7 cm (35 cm2) and were transplanted onto 6 wound sites in each of 7 adult participants (n = 42 sites total) from 2013 to 2017. Participants were followed for 2 to 5 years.RESULTS No participants experienced any serious related adverse events. Wound healing of 50% or greater by Investigator Global Assessment was present in 95% (36 of 38) of treated wounds versus 0% (0 of 6) of untreated control wounds at 6 months (P < 0.0001). At year 1, 68% (26 of 38) of treated wounds had 50% or greater healing compared with 17% (1 of 6) of control wounds (P = 0.025). At year 2, 71% (27 of 38) of treated wounds had 50% or greater healing compared with 17% (1 of 6) of control wounds (P = 0.019).CONCLUSION C7 expression persisted up to 2 years after treatment in 2 participants. Treated wounds with 50% or greater healing demonstrated improvement in patient-reported pain, itch, and wound durability. This study provides additional data to support the clinically meaningful benefit of treating chronic RDEB wounds with ex vivo, C7 gene–corrected autologous cell therapy. This approach was safe and promoted wound healing that was associated with improved patient-reported outcomes.TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01263379.FUNDING Epidermolysis Bullosa Research Partnership, Epidermolysis Bullosa Medical Research Foundation, NIH R01 AR055914, Office of Research and Development at the Palo Alto Veteran’s Affairs Medical Center, and the Dermatology Foundation.
Shaundra Eichstadt, Melissa Barriga, Anusha Ponakala, Claudia Teng, Ngon T. Nguyen, Zurab Siprashvili, Jaron Nazaroff, Emily S. Gorell, Albert S. Chiou, Lisa Taylor, Phuong Khuu, Douglas R. Keene, Kerri Rieger, Rohit K. Khosla, Louise K. Furukawa, H. Peter Lorenz, M. Peter Marinkovich, Jean Y. Tang
BACKGROUND Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridioides difficile infection (rCDI) in adults and children, but donor stool samples are currently screened for only a limited number of potential pathogens. We sought to determine whether putative procarcinogenic bacteria (enterotoxigenic Bacteroides fragilis, Fusobacterium nucleatum, and Escherichia coli harboring the colibactin toxin) could be durably transmitted from donors to patients during FMT.METHODS Stool samples were collected from 11 pediatric rCDI patients and their respective FMT donors prior to FMT as well as from the patients at 2–10 weeks, 10–20 weeks, and 6 months after FMT. Bacterial virulence factors in stool DNA extracts and stool cultures were measured by quantitative PCR: Bacteroides fragilis toxin (bft), Fusobacterium adhesin A (fadA), and Escherichia coli colibactin (clbB).RESULTS Four of 11 patients demonstrated sustained acquisition of a procarcinogenic bacteria. Whole genome sequencing was performed on colony isolates from one of these donor/recipient pairs and demonstrated that clbB+ E. coli strains present in the recipient after FMT were identical to a strain present in the donor, confirming strain transmission. Conversely, 2 patients exhibited clearance of procarcinogenic bacteria following FMT from a negative donor.CONCLUSION Both durable transmission and clearance of procarcinogenic bacteria occurred following FMT, suggesting that additional studies on appropriate screening measures for FMT donors and the long-term consequences and/or benefits of FMT are warranted.FUNDING Crohn’s & Colitis Foundation, the Bloomberg~Kimmel Institute for Cancer Immunotherapy at Johns Hopkins University School of Medicine, the National Cancer Institute, and the Canadian Institutes of Health Research.
Julia L. Drewes, Alina Corona, Uriel Sanchez, Yunfan Fan, Suchitra K. Hourigan, Melissa Weidner, Sarah D. Sidhu, Patricia J. Simner, Hao Wang, Winston Timp, Maria Oliva-Hemker, Cynthia L. Sears
Aberrant activation of the NF-κB transcription factors underlies chemoresistance in various cancer types, including colorectal cancer (CRC). Targeting the activating mechanisms, particularly with inhibitors to the upstream IκB kinase (IKK) complex, is a promising strategy to augment the effect of chemotherapy. However, clinical success has been limited, largely because of low specificity and toxicities of tested compounds. In solid cancers, the IKKs are driven predominantly by the Toll-like receptor (TLR)/IL-1 receptor family members, which signal through the IL-1 receptor–associated kinases (IRAKs), with isoform 4 (IRAK4) being the most critical. The pathogenic role and therapeutic value of IRAK4 in CRC have not been investigated. We found that IRAK4 inhibition significantly abrogates colitis-induced neoplasm in APCMin/+ mice, and bone marrow transplant experiments showed an essential role of IRAK4 in immune cells during neoplastic progression. Chemotherapy significantly enhances IRAK4 and NF-κB activity in CRC cells through upregulating TLR9 expression, which can in turn be suppressed by IRAK4 and IKK inhibitors, suggesting a feed-forward pathway that protects CRC cells from chemotherapy. Lastly, increased tumor phospho-IRAK4 staining or IRAK4 mRNA expression is associated with significantly worse survival in CRC patients. Our results support targeting IRAK4 to improve the effects of chemotherapy and outcomes in CRC.
Qiong Li, Yali Chen, Daoxiang Zhang, Julie Grossman, Lin Li, Namrata Khurana, Hongmei Jiang, Patrick M. Grierson, John Herndon, David G. DeNardo, Grant A. Challen, Jingxia Liu, Marianna B. Ruzinova, Ryan C. Fields, Kian-Huat Lim
The cardiac hormone atrial natriuretic peptide (ANP) is a central regulator of blood volume and a therapeutic target in hypertension and heart failure. Enhanced ANP activity in such conditions through inhibition of the degradative enzyme neprilysin has shown clinical efficacy but is complicated by consequences of simultaneous accumulation of a heterogeneous array of other hormones. Targets for specific ANP enhancement have not been available. Here, we describe a cis-acting antisense transcript (NPPA-AS1), which negatively regulates ANP expression in human cardiomyocytes. We show that NPPA-AS1 regulates ANP expression via facilitating NPPA repressor RE1-silencing transcription factor (REST) binding to its promoter, rather than forming an RNA duplex with ANP mRNA. Expression of ANP mRNA and NPPA-AS1 was increased and correlated in isolated strained human cardiomyocytes and in hearts from patients with advanced heart failure. Further, inhibition of NPPA-AS1 in vitro and in vivo resulted in increased myocardial expression of ANP, increased circulating ANP, increased renal cGMP, and lower blood pressure. The effects of NPPA-AS1 inhibition on NPPA expression in human cardiomyocytes were further marked under cell-strain conditions. Collectively, these results implicate the antisense transcript NPPA-AS1 as part of a physiologic self-regulatory ANP circuit and a viable target for specific ANP augmentation.
Selvi Celik, Mardjaneh Karbalaei Sadegh, Michael Morley, Carolina Roselli, Patrick T. Ellinor, Thomas Cappola, J. Gustav Smith, Olof Gidlöf
There is increased interest in whether bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) achieve their profound weight-lowering effects in morbidly obese individuals through the brain. Hypothalamic inflammation is a well-recognized etiologic factor in obesity pathogenesis and so represents a potential target of RYGB, but clinical evidence in support of this is limited. We therefore assessed hypothalamic T2-weighted signal intensities (T2W SI) and fractional anisotropy (FA) values, 2 validated radiologic measures of brain inflammation, in relation to BMI and fat mass, as well as circulating inflammatory (C-reactive protein; CrP) and metabolic markers in a cohort of 27 RYGB patients at baseline and 6 and 12 months after surgery. We found that RYGB progressively increased hypothalamic T2W SI values, while it progressively decreased hypothalamic FA values. Regression analyses further revealed that this could be most strongly linked to plasma CrP levels, which independently predicted hypothalamic FA values when adjusting for age, sex, fat mass, and diabetes diagnosis. These findings suggest that RYGB has a major time-dependent impact on hypothalamic inflammation status, possibly by attenuating peripheral inflammation. They also suggest that hypothalamic FA values may provide a more specific radiologic measure of hypothalamic inflammation than more commonly used T2W SI values.
Mohammed K. Hankir, Michael Rullmann, Florian Seyfried, Sven Preusser, Sindy Poppitz, Stefanie Heba, Konstantinos Gousias, Jana Hoyer, Tatjana Schütz, Arne Dietrich, Karsten Müller, Burkhard Pleger
Cetuximab, an EGFR-blocking antibody, is currently approved for treatment of metastatic head and neck squamous cell carcinoma (HNSCC), but its response rate is limited. In addition to blocking EGFR-stimulated cell signaling, cetuximab can induce endocytosis of ASCT2, a glutamine transporter associated with EGFR in a complex, leading to glutathione biosynthesis inhibition and cellular sensitization to ROS. Pyruvate dehydrogenase kinase-1 (PDK1), a key mitochondrial enzyme overexpressed in cancer cells, redirects glucose metabolism from oxidative phosphorylation toward aerobic glycolysis. In this study, we tested the hypothesis that targeting PDK1 is a rational approach to synergize with cetuximab through ROS overproduction. We found that combination of PDK1 knockdown or inhibition by dichloroacetic acid (DCA) with ASCT2 knockdown or with cetuximab treatment induced ROS overproduction and apoptosis in HNSCC cells, and this effect was independent of effective inhibition of EGFR downstream pathways but could be lessened by N-acetyl cysteine, an anti-oxidative agent. In several cetuximab-resistant HNSCC xenograft models, DCA plus cetuximab induced marked tumor regression, whereas either agent alone failed to induce tumor regression. Our findings call for potentially novel clinical trials of combining cetuximab and DCA in patients with cetuximab-sensitive EGFR-overexpressing tumors and patients with cetuximab-resistant EGFR-overexpressing tumors.
Haiquan Lu, Yang Lu, Yangyiran Xie, Songbo Qiu, Xinqun Li, Zhen Fan
MD-PhD programs were established in the 1950s as a new curriculum for training physician-scientists. Since then, the number of programs has grown considerably; however, concerns about the health of the US physician-scientist workforce have grown, as well. The largest attempt to date to assess whether MD-PhD programs are fulfilling their mission was the national MD-PhD program outcomes study, which was released as an American Association of Medical Colleges report in 2018. That study gathered information on 10,591 graduates of 80 MD-PhD programs over 50 years and concluded that most graduates have followed careers consistent with their training. Here, we provide additional analysis, drawing on survey data provided by 64.1% of alumni (75.9% of alumni with valid email addresses), plus program-supplied current workplace data for survey nonresponders to examine the relationships between medical specialty choices, training duration, research effort, and success in obtaining research funding. The results show that residency choices affect critical aspects of the physician-scientist career path, including where graduates work, how long it takes them to obtain an independent appointment in academia, and the amount of their professional time that is devoted to research. Entrants into MD-PhD programs are older, on average, now than when the programs were first established and are taking longer to graduate and complete postgraduate training. Although we found a positive relationship between professional effort devoted to research and the likelihood of having research funding, we found little evidence that the increase in training duration produces an increase in subsequent research effort. These data should provide both guidance for anyone considering this career path and insights for those who train and hire the next generation of physician-scientists.
Lawrence F. Brass, Myles H. Akabas
In 2015, a nation-wide effort was launched to track the careers of over 10,000 MD-PhD program graduates. Data were obtained by surveys sent to alumni, inquiries sent to program directors, and searches in American Association of Medical Colleges (AAMC) databases. Here, we present an analysis of the data, focusing on the impact of sex, race, and ethnicity on career outcomes. The results show that diversity among trainees has increased since the earliest MD-PhD programs, although it still lags considerably behind the US population. Training duration, which includes time to graduation as well as time to first independent position, was similar for men and women and for minority and nonminority alumni, as were most choices of medical specialties. Regardless of minority status and sex, most survey responders reported that they are working in academia, research institutes, federal agencies, or industry. These similarities were, however, accompanied by several noteworthy differences: (a) Based on AAMC Faculty Roster data rather than survey responses, women were less likely than men to have had a full-time faculty appointment, (b) minorities who graduated after 1985 had a longer average time to degree than nonminorities, (c) fewer women and minorities have NIH grants, (d) fewer women reported success in moving from a mentored to an independent NIH award, and (e) women in the most recent graduation cohort reported spending less time on research than men. Collectively, these results suggest that additional efforts need to be made to recruit women and minorities into MD-PhD programs and, once recruited, to understand the drivers behind the differences that have emerged in their career paths.
Myles H. Akabas, Lawrence F. Brass