Issue published October 15, 2024 Previous issue

On the cover: Regenerative inflammation in skeletal muscle repair

Patsalos et al. report on diverse myeloid cell subsets that organize in functional multilayered tissue zones, crucial for effective muscle repair. The cover shows a generative AI depiction of macrophage subtypes navigating through a regenerating muscle, highlighting their pivotal role in the healing process. Image credit: Andreas Patsalos/Adobe Firefly.

Letters to the Editor
Conversations with Giants in Medicine
Abstract

Authors

Ushma S. Neill

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Review Series
Abstract

Substance use disorders (SUDs) are highly prevalent and associated with excess morbidity, mortality, and economic costs. Thus, there is considerable interest in the early identification of individuals who may be more susceptible to developing SUDs and in improving personalized treatment decisions for those who have SUDs. SUDs are known to be influenced by both genetic and environmental factors. Polygenic scores (PGSs) provide a single measure of genetic liability that could be used as a biomarker in predicting disease development, progression, and treatment response. Although PGSs are rapidly being integrated into clinical practice, there is little information to guide clinicians in their responsible use and interpretation. In this Review, we discuss the potential benefits and pitfalls of the use of PGSs in the clinical care of SUDs, highlighting current research. We also provide suggestions for important considerations prior to implementing the clinical use of PGSs and recommend future directions for research.

Authors

Rachel L. Kember, Christal N. Davis, Kyra L. Feuer, Henry R. Kranzler

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Abstract

Opioid misuse, addiction, and associated overdose deaths remain global public health crises. Despite the tremendous need for pharmacological treatments, current options are limited in number, use, and effectiveness. Fundamental leaps forward in our understanding of the biology driving opioid addiction are needed to guide development of more effective medication-assisted therapies. This Review focuses on the omics-identified biological features associated with opioid addiction. Recent GWAS have begun to identify robust genetic associations, including variants in OPRM1, FURIN, and the gene cluster SCAI/PPP6C/RABEPK. An increasing number of omics studies of postmortem human brain tissue examining biological features (e.g., histone modification and gene expression) across different brain regions have identified broad gene dysregulation associated with overdose death among opioid misusers. Drawn together by meta-analysis and multi-omic systems biology, and informed by model organism studies, key biological pathways enriched for opioid addiction–associated genes are emerging, which include specific receptors (e.g., GABAB receptors, GPCR, and Trk) linked to signaling pathways (e.g., Trk, ERK/MAPK, orexin) that are associated with synaptic plasticity and neuronal signaling. Studies leveraging the agnostic discovery power of omics and placing it within the context of functional neurobiology will propel us toward much-needed, field-changing breakthroughs, including identification of actionable targets for drug development to treat this devastating brain disease.

Authors

Eric O. Johnson, Heidi S. Fisher, Kyle A. Sullivan, Olivia Corradin, Sandra Sanchez-Roige, Nathan C. Gaddis, Yasmine N. Sami, Alice Townsend, Erica Teixeira Prates, Mirko Pavicic, Peter Kruse, Elissa J. Chesler, Abraham A. Palmer, Vanessa Troiani, Jason A. Bubier, Daniel A. Jacobson, Brion S. Maher

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Abstract

Cannabis has been legalized for medical and recreational purposes in multiple countries. A large number of people are using cannabis and some will develop cannabis use disorder (CUD). There is a growing recognition that CUD requires specific interventions. This Review will cover this topic from a variety of perspectives, with a particular emphasis on neurobiological findings and innovative treatment approaches that are being pursued. We will first describe the epidemiology and burden of disease of CUD, including risk factors associated with CUD (both in terms of general risk and genetic risk variants). Neurobiological alterations identified in brain imaging studies will be presented. Several psychosocial interventions that are useful for the management of CUD, including motivational enhancement therapy, behavioral and cognitive therapy, and contingency management, will be covered. Although no pharmacological interventions are yet approved for CUD, we present the most promising pharmacological interventions being tested.

Authors

Bernard Le Foll, Victor M. Tang, Sergio Rueda, Leanne V. Trick, Isabelle Boileau

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Review
Abstract

As epigenetic therapies continue to gain ground as potential treatment strategies for cancer and other diseases, compounds that target histone lysine methylation and the enzyme complexes represent a major frontier for therapeutic development. Clinically viable therapies targeting the activities of histone lysine methyltransferases (HKMT) and demethylases (HKDMs) have only recently begun to emerge following FDA approval of the EZH2 inhibitor tazemetostat in 2020 and remain limited to compounds targeting the well-studied SET domain–containing HKMTs and their opposing HKDMs. These include the H3K27 methyltransferases EZH2/EZH1, the singular H3K79 methyltransferase DOT1L, and the H3K4 methyltransferase MLL1/COMPASS as well as H3K9 and H3K36 methyltransferases. They additionally include the H3K4/9-preferential demethylase LSD1 and the H3K4-, H3K27-, and H3K36-preferential KDM5, KDM6, and KDM2 demethylase subfamilies, respectively. This Review discusses the results of recent clinical and preclinical studies relevant to all of these existing and potential therapies. It provides an update on advancements in therapeutic development, as well as more basic molecular understanding, within the past 5 years approximately. It also offers a perspective on histone lysine methylation that departs from the long-predominant “histone code” metaphor, emphasizing complex-disrupting inhibitors and proximity-based approaches rather than catalytic domain inhibitors in the outlook for future therapeutic development.

Authors

Sarah Gold, Ali Shilatifard

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Commentaries
Abstract

The precise conditions by which cytokines drive cancer is relevant to improving immune checkpoint inhibition (ICI) responses while decreasing toxicity. In this issue of the JCI, Kao et al. investigated T helper cell pathways in patients with solid tumors receiving ICI. The authors evaluated T cell populations, cytokine signatures, immune related adverse events (irAEs), and survival outcomes. Patients with a history of autoimmune disorders were more likely to develop irAEs. Notably, blood samples from patients on treatment showed that elevations in IL-5, IL-6, IL-17f, and TNF-α were associated with an increased risk for grade 2 or higher irAEs. Moreover, IL-6 was associated with decreased objective response rate and worse cancer-specific and all-cause mortality. These findings may help guide decisions for optimizing ICI efficacy while minimizing toxicity and suggest that IL-6 blockade may improve response and decrease toxicity in solid tumors.

Authors

Alexandra M. Haugh, Adil I. Daud

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Abstract

Kidney transplantation from donors with HIV to recipients with HIV (HIV D+/R+) is an emerging practice that has shown substantial clinical benefit. Sustained HIV superinfection, whereby a transplant recipient acquires a new strain of HIV from their organ donor, is a theoretical risk, which might increase chances of viral failure. In this issue of the JCI, Travieso, Stadtler, and colleagues present phylogenetic analysis of HIV from kidney tissue, urine, plasma, and cells from 12 HIV D+/R+ kidney transplants out to five years of follow-up. Early after transplant, donor HIV was transiently detected in five of 12 recipients, primarily from donors with untreated HIV and high-level viremia, consistent with a viral inoculum. Long-term, donor HIV was not detected in any recipients, demonstrating no sustained HIV superinfection. These reassuring data support earlier findings from South Africa and the United States and further confirm the safety of HIV D+/R+ transplantation.

Authors

Christine M. Durand, Andrew D. Redd

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Abstract

Expression of tissue-restricted antigens (TRAs) within the thymus is critical for the establishment of self-tolerance; however, exact mechanisms regulating the expression of TRAs has proven more complex than previously appreciated. In this issue of the JCI, Muro et al. identify a central role for protein arginine methyltransferase 5 (PRMT5) in posttranscriptional regulation of TRAs and thereby central tolerance. Using conditional KO mice, the authors showed that thymic deficiency of Prmt5 predisposed mice to developing autoimmune diseases while enhancing antitumor efficacy. These studies provide insight into the role of PRMT5 in shaping the T cell repertoire with implications for the development of therapies.

Authors

Rathan Kumar, Parvathi Ranganathan

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Research Letters
Abstract

Authors

Maegan R. Manning, Jana Blazkova, Jesse S. Justement, Victoria Shi, Brooke D. Kennedy, M. Ali Rai, Catherine A. Seamon, Kathleen Gittens, Michael C. Sneller, Susan Moir, Tae-Wook Chun

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Research Articles
Abstract

Chronic low back pain (LBP) can severely affect daily physical activity. Aberrant osteoclast-mediated resorption leads to porous endplates, which allow the sensory innervation that causes LBP. Here, we report that expression of the proton-activated chloride (PAC) channel was induced during osteoclast differentiation in the porous endplates via a RANKL/NFATc1 signaling pathway. Extracellular acidosis evoked robust PAC currents in osteoclasts. An acidic environment of porous endplates and elevated PAC activation–enhanced osteoclast fusion provoked LBP. Furthermore, we found that genetic knockout of the PAC gene Pacc1 significantly reduced endplate porosity and spinal pain in a mouse LBP model, but it did not affect bone development or homeostasis of bone mass in adult mice. Moreover, both the osteoclast bone-resorptive compartment environment and PAC traffic from the plasma membrane to endosomes to form an intracellular organelle Cl channel had a low pH of approximately 5.0. The low pH environment activated the PAC channel to increase sialyltransferase St3gal1 expression and sialylation of TLR2 in the initiation of osteoclast fusion. Aberrant osteoclast-mediated resorption is also found in most skeletal disorders, including osteoarthritis, ankylosing spondylitis, rheumatoid arthritis, heterotopic ossification, and enthesopathy. Thus, elevated Pacc1 expression and PAC activity could be a potential therapeutic target for the treatment of LBP and osteoclast-associated pain.

Authors

Peng Xue, Weixin Zhang, Mengxi Shen, Junhua Yang, Jiachen Chu, Shenyu Wang, Mei Wan, Junying Zheng, Zhaozhu Qiu, Xu Cao

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Abstract

Tissue regeneration is orchestrated by macrophages that clear damaged cells and promote regenerative inflammation. How macrophages spatially adapt and diversify their functions to support the architectural requirements of actively regenerating tissue remains unknown. In this study, we reconstructed the dynamic trajectories of myeloid cells isolated from acutely injured and early stage dystrophic muscles. We identified divergent subsets of monocytes/macrophages and DCs and validated markers (e.g., glycoprotein NMB [GPNMB]) and transcriptional regulators associated with defined functional states. In dystrophic muscle, specialized repair-associated subsets exhibited distinct macrophage diversity and reduced DC heterogeneity. Integrating spatial transcriptomics analyses with immunofluorescence uncovered the ordered distribution of subpopulations and multilayered regenerative inflammation zones (RIZs) where distinct macrophage subsets are organized in functional zones around damaged myofibers supporting all phases of regeneration. Importantly, intermittent glucocorticoid treatment disrupted the RIZs. Our findings suggest that macrophage subtypes mediated the development of the highly ordered architecture of regenerative tissues, unveiling the principles of the structured yet dynamic nature of regenerative inflammation supporting effective tissue repair.

Authors

Andreas Patsalos, Laszlo Halasz, Darby Oleksak, Xiaoyan Wei, Gergely Nagy, Petros Tzerpos, Thomas Conrad, David W. Hammers, H. Lee Sweeney, Laszlo Nagy

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Abstract

Current research reports that lactate affects Treg metabolism, although the precise mechanism has only been partially elucidated. In this study, we presented evidence demonstrating that elevated lactate levels enhanced cell proliferation, suppressive capabilities, and oxidative phosphorylation (OXPHOS) in human Tregs. The expression levels of Monocarboxylate Transporters 1/2/4 (MCT1/2/4) regulate intracellular lactate concentration, thereby influencing the varying responses observed in naive Tregs and memory Tregs. Through mitochondrial isolation, sequencing, and analysis of human Tregs, we determined that α-1,3-Mannosyl-Glycoprotein 2-β-N-Acetylglucosaminyltransferase (MGAT1) served as the pivotal driver initiating downstream N-glycosylation events involving progranulin (GRN) and hypoxia-upregulated 1 (HYOU1), consequently enhancing Treg OXPHOS. The mechanism by which MGAT1 was upregulated in mitochondria depended on elevated intracellular lactate that promoted the activation of XBP1s. This, in turn, supported MGAT1 transcription as well as the interaction of lactate with the translocase of the mitochondrial outer membrane 70 (TOM70) import receptor, facilitating MGAT1 translocation into mitochondria. Pretreatment of Tregs with lactate reduced mortality in a xenogeneic graft-versus-host disease (GvHD) model. Together, these findings underscored the active regulatory role of lactate in human Treg metabolism through the upregulation of MGAT1 transcription and its facilitated translocation into the mitochondria.

Authors

Jinren Zhou, Jian Gu, Qufei Qian, Yigang Zhang, Tianning Huang, Xiangyu Li, Zhuoqun Liu, Qing Shao, Yuan Liang, Lei Qiao, Xiaozhang Xu, Qiuyang Chen, Zibo Xu, Yu Li, Ji Gao, Yufeng Pan, Yiming Wang, Roderick O’Connor, Keli L. Hippen, Ling Lu, Bruce R. Blazar

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Abstract

BACKGROUND Immune-related adverse events (irAEs) and their associated morbidity/mortality are a key concern for patients receiving immune checkpoint inhibitors (ICIs). Prospective evaluation of the drivers of irAEs in a diverse pan-tumor cohort is needed to identify patients at greatest risk and to develop rational treatment and interception strategies.METHODS In an observational study, we prospectively collected blood samples and performed regular clinical evaluations for irAEs in patients receiving ICI therapy as standard of care for solid tumors. We performed in-parallel analysis of cytokines by Luminex immunoassay and circulating immune cells by cytometry by time-of-flight (CyTOF) at baseline and on treatment to investigate mechanisms of irAEs.RESULTS We enrolled 111 patients, of whom 40.5% developed a symptomatic irAE (grade ≥ 2). Development of a grade ≥ 2 irAE was positively associated with the use of combination ICI and a history of an autoimmune disorder. Early changes in T helper 17 (Th17) (IL-6, IL-17f), type 2 (IL-5, IL-13, IL-25), and type 1 (TNF-α) cytokine signatures and congruent on-treatment expansions of Th17 and Th2 effector memory (Th2EM) T cell populations in peripheral blood were positively associated with the development of grade ≥2 irAEs. IL-6 levels were also associated with inferior cancer-specific survival and overall survival.CONCLUSIONS In a diverse, prospective pan-tumor cohort, Th17 and Th2 skewing during early ICI treatment was associated with the development of clinically relevant irAEs but not antitumor responses, providing possible targets for monitoring and therapeutic interventions.FUNDING Johns Hopkins Bloomberg-Kimmel Institute for Cancer Immunotherapy, the NCI SPORE in Gastrointestinal Cancers (P50 CA062924), NCI grant (R50CA243627 to LD), the NIH Center Core Grant (P30 CA006973), Swim Across America (to MY), NIAMS (K23AR075872 to LC), and imCORE-Genentech grant 137515 (to Johns Hopkins Medicine on behalf of MY).

Authors

Chester J. Kao, Soren Charmsaz, Stephanie L. Alden, Madelena Brancati, Howard L. Li, Aanika Balaji, Kabeer Munjal, Kathryn Howe, Sarah Mitchell, James Leatherman, Ervin Griffin, Mari Nakazawa, Hua-Ling Tsai, Ludmila Danilova, Chris Thoburn, Jennifer Gizzi, Nicole E. Gross, Alexei Hernandez, Erin M. Coyne, Sarah M. Shin, Jayalaxmi Suresh Babu, George W. Apostol, Jennifer Durham, Brian J. Christmas, Maximilian F. Konig, Evan J. Lipson, Jarushka Naidoo, Laura C. Cappelli, Aliyah Pabani, Yasser Ged, Marina Baretti, Julie Brahmer, Jean Hoffman-Censits, Tanguy Y. Seiwert, Rachel Garonce-Hediger, Aditi Guha, Sanjay Bansal, Laura Tang, Elizabeth M. Jaffee, G. Scott Chandler, Rajat Mohindra, Won Jin Ho, Mark Yarchoan

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Abstract

Translation of mRNA to protein is tightly regulated by transfer RNAs (tRNAs), which are subject to various chemical modifications that maintain structure, stability, and function. Deficiency of tRNA N7-methylguanosine (m7G) modification in patients causes a type of primordial dwarfism, but the underlying mechanism remains unknown. Here we report that the loss of m7G rewires cellular metabolism, leading to the pathogenesis of primordial dwarfism. Conditional deletion of the catalytic enzyme Mettl1 or missense mutation of the scaffold protein Wdr4 severely impaired endochondral bone formation and bone mass accrual. Mechanistically, Mettl1 knockout decreased abundance of m7G-modified tRNAs and inhibited translation of mRNAs relating to cytoskeleton and Rho GTPase signaling. Meanwhile, Mettl1 knockout enhanced cellular energy metabolism despite incompetent proliferation and osteogenic commitment. Further exploration revealed that impairment of Rho GTPase signaling upregulated the level of branched-chain amino acid transaminase 1 (BCAT1) that rewired cell metabolism and restricted intracellular α-ketoglutarate (αKG). Supplementation of αKG ameliorated the skeletal defect of Mettl1-deficient mice. In addition to the selective translation of metabolism-related mRNAs, we further revealed that Mettl1 knockout globally regulated translation via integrated stress response (ISR) and mammalian target of rapamycin complex 1 (mTORC1) signaling. Restoring translation by targeting either ISR or mTORC1 aggravated bone defects of Mettl1-deficient mice. Overall, our study unveils a critical role of m7G tRNA modification in bone development by regulation of cellular metabolism and indicates suspension of translation initiation as a quality control mechanism in response to tRNA dysregulation.

Authors

Qiwen Li, Shuang Jiang, Kexin Lei, Hui Han, Yaqian Chen, Weimin Lin, Qiuchan Xiong, Xingying Qi, Xinyan Gan, Rui Sheng, Yuan Wang, Yarong Zhang, Jieyi Ma, Tao Li, Shuibin Lin, Chenchen Zhou, Demeng Chen, Quan Yuan

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Abstract

Glioblastoma (GBM) is a highly aggressive and malignant brain tumor with limited therapeutic options and a poor prognosis. Despite current treatments, the invasive nature of GBM often leads to recurrence. A promising alternative strategy is to harness the potential of the immune system against tumor cells. Our previous data showed that the BVax (B cell–based vaccine) can induce therapeutic responses in preclinical models of GBM. In this study, we aimed to characterize the antigenic reactivity of BVax-derived Abs and evaluate their therapeutic potential. We performed immunoproteomics and functional assays in murine models and samples from patients with GBM. Our investigations revealed that BVax distributed throughout the GBM tumor microenvironment and then differentiated into Ab-producing plasmablasts. Proteomics analyses indicated that the Abs produced by BVax had unique reactivity, predominantly targeting factors associated with cell motility and the extracellular matrix. Crucially, these Abs inhibited critical processes such as GBM cell migration and invasion. These findings provide valuable insights into the therapeutic potential of BVax-derived Abs for patients with GBM, pointing toward a novel direction for GBM immunotherapy.

Authors

Si Wang, Brandyn A. Castro, Joshua L. Katz, Victor Arrieta, Hinda Najem, Gustavo I. Vazquez-Cervantes, Hanxiao Wan, Ian E. Olson, David Hou, Mark Dapash, Leah K. Billingham, Tzu-yi Chia, Chao Wei, Aida Rashidi, Leonidas C. Platanias, Kathleen McCortney, Craig M. Horbinski, Roger Stupp, Peng Zhang, Atique U. Ahmed, Adam M. Sonabend, Amy B. Heimberger, Maciej S. Lesniak, Cécile Riviere-Cazaux, Terry Burns, Jason Miska, Mariafausta Fischietti, Catalina Lee-Chang

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Abstract

Immunological self-tolerance is established in the thymus by the expression of virtually all self-antigens, including tissue-restricted antigens (TRAs) and cell-type–restricted antigens (CRAs). Despite a wealth of knowledge about the transcriptional regulation of TRA genes, posttranscriptional regulation remains poorly understood. Here, we show that protein arginine methylation plays an essential role in central immune tolerance by maximizing the self-antigen repertoire in medullary thymic epithelial cells (mTECs). Protein arginine methyltransferase-5 (Prmt5) was required for pre-mRNA splicing of certain key genes in tolerance induction, including Aire as well as various genes encoding TRAs. Mice lacking Prmt5 specifically in thymic epithelial cells exhibited an altered thymic T cell selection, leading to the breakdown of immune tolerance accompanied by both autoimmune responses and enhanced antitumor immunity. Thus, arginine methylation and transcript splicing are essential for establishing immune tolerance and may serve as a therapeutic target in autoimmune diseases as well as cancer immunotherapy.

Authors

Ryunosuke Muro, Takeshi Nitta, Sachiko Nitta, Masayuki Tsukasaki, Tatsuo Asano, Kenta Nakano, Tadashi Okamura, Tomoki Nakashima, Kazuo Okamoto, Hiroshi Takayanagi

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Abstract

Parkinson’s disease (PD) is characterized by age-dependent neurodegeneration and the accumulation of toxic phosphorylated α-synuclein (pS129-α-syn). The mechanisms underlying these crucial pathological changes remain unclear. Mutations in parkin RBR E3 ubiquitin protein ligase (PARK2), the gene encoding parkin that is phosphorylated by PTEN-induced putative kinase 1 (PINK1) to participate in mitophagy, cause early onset PD. However, current parkin-KO mouse and pig models do not exhibit neurodegeneration. In the current study, we utilized CRISPR/Cas9 technology to establish parkin-deficient monkey models at different ages. We found that parkin deficiency leads to substantia nigra neurodegeneration in adult monkey brains and that parkin phosphorylation decreases with aging, primarily due to increased insolubility of parkin. Phosphorylated parkin is important for neuroprotection and the reduction of pS129-α-syn. Consistently, overexpression of WT parkin, but not a mutant form that cannot be phosphorylated by PINK1, reduced the accumulation of pS129-α-syn. These findings identify parkin phosphorylation as a key factor in PD pathogenesis and suggest it as a promising target for therapeutic interventions.

Authors

Rui Han, Qi Wang, Xin Xiong, Xiusheng Chen, Zhuchi Tu, Bang Li, Fei Zhang, Chunyu Chen, Mingtian Pan, Ting Xu, Laiqiang Chen, Zhifu Wang, Yanting Liu, Dajian He, Xiangyu Guo, Feng He, Peng Wu, Peng Yin, Yunbo Liu, Xiaoxin Yan, Shihua Li, Xiao-Jiang Li, Weili Yang

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Abstract

BACKGROUND Donor cell engraftment is a prerequisite of successful allogeneic hematopoietic stem cell transplantation. Based on peripheral blood analyses, it is characterized by early myeloid recovery and T and B cell lymphopenia. However, cellular networks associated with bone marrow engraftment of allogeneic human cells have been poorly described.METHODS Mass cytometry and CITE-Seq analyses were performed on bone marrow cells 3 months after transplantation in patients with acute myelogenous leukemia.RESULTS Mass cytometric analyses in 26 patients and 20 healthy controls disclosed profound alterations in myeloid and B cell progenitors, with a shift toward terminal myeloid differentiation and decreased B cell progenitors. Unsupervised analysis separated recipients into 2 groups, one of them being driven by previous graft-versus-host disease (R2 patients). We then used single-cell CITE-Seq to decipher engraftment, which resolved 36 clusters, encompassing all bone marrow cellular components. Hematopoiesis in transplant recipients was sustained by committed myeloid and erythroid progenitors in a setting of monocyte-, NK cell–, and T cell–mediated inflammation. Gene expression revealed major pathways in transplant recipients, namely, TNF-α signaling via NF-κB and the IFN-γ response. The hallmark of allograft rejection was consistently found in clusters from transplant recipients, especially in R2 recipients.CONCLUSION Bone marrow cell engraftment of allogeneic donor cells is characterized by a state of emergency hematopoiesis in the setting of an allogeneic response driving inflammation.FUNDING This study was supported by the French National Cancer Institute (Institut National du Cancer; PLBIO19-239) and by an unrestricted research grant by Alexion Pharmaceuticals.

Authors

Jennifer Bordenave, Dorota Gajda, David Michonneau, Nicolas Vallet, Mathieu Chevalier, Emmanuelle Clappier, Pierre Lemaire, Stéphanie Mathis, Marie Robin, Aliénor Xhaard, Flore Sicre de Fontbrune, Aurélien Corneau, Sophie Caillat-Zucman, Regis Peffault de Latour, Emmanuel Curis, Gérard Socié

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Abstract

BACKGROUND Most humans have been infected with cytomegalovirus (CMV) by midlife without clinical signs of disease. However, in settings in which the immune system is undeveloped or compromised, the virus is not adequately controlled and consequently presents a major infectious cause of both congenital disease during pregnancy as well as opportunistic infection in children and adults. With clear evidence that risk to the fetus varies with gestational age at the time of primary maternal infection, further research on humoral responses to primary CMV infection during pregnancy is needed.METHODS Here, systems serology tools were applied to characterize antibody responses to CMV infection in pregnant and nonpregnant women experiencing either primary or chronic infection.RESULTS Whereas strikingly different antibody profiles were observed depending on infection status, limited differences were associated with pregnancy status. Beyond known differences in IgM responses used clinically for identification of primary infection, distinctions observed in IgA and FcγR-binding antibodies and among antigen specificities accurately predicted infection status. Machine learning was used to define the transition from primary to chronic states and predict time since infection with high accuracy. Humoral responses diverged over time in an antigen-specific manner, with IgG3 responses toward tegument decreasing over time as typical of viral infections, while those directed to pentamer and glycoprotein B were lower during acute and greatest during chronic infection.CONCLUSION In sum, this work provides insights into the antibody response associated with CMV infection status in the context of pregnancy, revealing aspects of humoral immunity that have the potential to improve CMV diagnostics.FUNDING CYMAF consortium and NIH NIAID.

Authors

Andrew P. Hederman, Christopher A.L. Remmel, Shilpee Sharma, Harini Natarajan, Joshua A. Weiner, Daniel Wrapp, Catherine Donner, Marie-Luce Delforge, Piera d’Angelo, Milena Furione, Chiara Fornara, Jason S. McLellan, Daniele Lilleri, Arnaud Marchant, Margaret E. Ackerman

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Abstract

The blood-retina barrier (BRB), which is disrupted in diabetic retinopathy (DR) and uveitis, is an important anatomical characteristic of the retina, regulating nutrient, waste, water, protein, and immune cell flux. The BRB is composed of endothelial cell tight junctions, pericytes, astrocyte end feet, a collagen basement membrane, and perivascular macrophages. Despite the importance of the BRB, retinal perivascular macrophage function remains unknown. We found that retinal perivascular macrophages resided on postcapillary venules in the superficial vascular plexus and expressed MHC class II. Using single-cell RNA-Seq, we found that perivascular macrophages expressed a prochemotactic transcriptome and identified platelet factor 4 (Pf4, also known as CXCL4) as a perivascular macrophage marker. We used Pf4Cre mice to specifically deplete perivascular macrophages. To model retinal inflammation, we performed intraocular CCL2 injections. Ly6C+ monocytes crossed the BRB proximal to perivascular macrophages. Depletion of perivascular macrophages severely hampered Ly6C+ monocyte infiltration. These data suggest that retinal perivascular macrophages orchestrate immune cell migration across the BRB, with implications for inflammatory ocular diseases including DR and uveitis.

Authors

Jacob K. Sterling, Amrita Rajesh, Steven Droho, Joyce Gong, Andrew L. Wang, Andrew P. Voigt, C. Elysse Brookins, Jeremy A. Lavine

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Abstract

BACKGROUND The HIV Organ Policy Equity (HOPE) Act allows individuals living with HIV to accept organs from donors with HIV. This practice widens the pool of available organs, but also presents important virological issues, including the potential for HIV superinfection of the recipient, viral persistence in the kidney, and loss of virological control.METHODS We addressed these issues by performing in-depth longitudinal viral sequence analyses on urine, blood, and urine-derived renal epithelial cells from 12 recipients of HIV+ kidney allografts.RESULTS We amplified donor-derived HIV-1 env sequences in 5 out of 12 recipients after transplant. These donor-derived env sequences were amplified from recipient urine, urine-derived renal epithelial cells, and plasma between 12 and 96 hours after transplant and remained detectable up to 16 days after transplant. Env sequences were also detected in kidney biopsies taken from the allografts before implantation in 6 out of the 12 transplant cases, indicating the presence of donor virus within the organ. One recipient had a viremic episode 3.5 years after transplantation as a result of antiretroviral therapy (ART) interruption. Only recipient strain viral sequences were detected in blood, suggesting that the donor virus, if still present, was not reactivated during the temporary ART withdrawal.CONCLUSIONS This study demonstrates that the HIV env sequences in a donor kidney can be amplified from biopsies taken from the allograft before implantation and can be detected transiently in blood and urine samples collected from the organ recipients after transplantation.FUNDING National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) grant number R01DK131497.

Authors

Tatianna Travieso, Hannah Stadtler, Naseem Alavian, Feng Gao, Mary Klotman, Cameron Robert Wolfe, Maria Blasi

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Abstract

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Authors

Jonathan Bohlen, Ivan Bagarić, Taja Vatovec, Masato Ogishi, Syed F. Ahmed, Axel Cederholm, Lori Buetow, Steicy Sobrino, Corentin Le Floc’h, Carlos A. Arango-Franco, Luis Seabra, Marine Michelet, Federica Barzaghi, Davide Leardini, Francesco Saettini, Francesca Vendemini, Francesco Baccelli, Albert Catala, Eleonora Gambineri, Marinella Veltroni, Yurena Aguilar de la Red, Gillian I. Rice, Filippo Consonni, Laureline Berteloot, Laetitia Largeaud, Francesca Conti, Cécile Roullion, Cécile Masson, Boris Bessot, Yoann Seeleuthner, Tom Le Voyer, Darawan Rinchai, Jérémie Rosain, Anna-Lena Neehus, Lucia Erazo-Borrás, Hailun Li, Zarah Janda, En-Jui Cho, Edoardo Muratore, Camille Soudée, Candice Lainé, Eric Delabesse, Claire Goulvestre, Cindy S. Ma, Anne Puel, Stuart G. Tangye, Isabelle André, Christine Bole-Feysot, Laurent Abel, Miriam Erlacher, Shen-Ying Zhang, Vivien Béziat, Chantal Lagresle-Peyrou, Emmanuelle Six, Marlène Pasquet, Laia Alsina, Alessandro Aiuti, Peng Zhang, Yanick J. Crow, Nils Landegren, Riccardo Masetti, Danny T. Huang, Jean-Laurent Casanova, Jacinta Bustamante

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Abstract

The most common mutation in surfactant protein C gene (SFTPC), SFTPCI73T, causes interstitial lung disease with few therapeutic options. We previously demonstrated that EMC3, an important component of the multiprotein endoplasmic reticulum membrane complex (EMC), is required for surfactant homeostasis in alveolar type 2 epithelial (AT2) cells at birth. In the present study, we investigated the role of EMC3 in the control of SFTPCI73T metabolism and its associated alveolar dysfunction. Using a knock-in mouse model phenocopying the I73T mutation, we demonstrated that conditional deletion of Emc3 in AT2 cells rescued alveolar remodeling/simplification defects in neonatal and adult mice. Proteomic analysis revealed that Emc3 depletion reversed the disruption of vesicle trafficking pathways and rescued the mitochondrial dysfunction associated with I73T mutation. Affinity purification-mass spectrometry analysis identified potential EMC3 interacting proteins in lung AT2 cells, including Valosin Containing Protein (VCP) and its interactors. Treatment of SftpcI73T knock-in mice and SFTPCI73T expressing iAT2 cells derived from SFTPCI73T patient-specific iPSCs with the specific VCP inhibitor CB5083 restored alveolar structure and SFTPCI73T trafficking respectively. Taken together, the present work identifies the EMC complex and VCP in the metabolism of the disease-associated SFTPCI73T mutant, providing novel therapeutical targets for SFTPCI73T-associated interstitial lung disease.

Authors

Xiaofang Tang, Wei Wei, Yuqing Sun, Timothy E. Weaver, Ernesto S. Nakayasu, Geremy Clair, John M. Snowball, Cheng-Lun Na, Karen S. Apsley, Emily P. Martin, Darrell N. Kotton, Konstantinos-Dionysios Alysandratos, Jiuzhou Huo, Jeffery D. Molkentin, William A. Gower, Xinhua Lin, Jeffrey A. Whitsett

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Abstract

Impaired fatty acid oxidation (FAO) and the therapeutic benefits of FAO restoration have been revealed in sepsis. However, the regulatory factors contributing to FAO dysfunction during sepsis remain inadequately clarified. In this study, we identified a subset of lipid-associated macrophages characterized by high expression of trigger receptor expressed on myeloid cells 2 (TREM2) and demonstrated that TREM2 acted as a suppressor of FAO to increase the susceptibility to sepsis. TREM2 expression was markedly up-regulated in sepsis patients and correlated with the severity of sepsis. Knock out of TREM2 in macrophages improved the survival rate and reduced inflammation and organ injuries of sepsis mice. Notably, TREM2-deficient mice exhibited decreased triglyceride accumulation and an enhanced FAO rate. Further observations showed that the blockade of FAO substantially abolished the alleviated symptoms observed in TREM2 knockout mice. Mechanically, we demonstrated that TREM2 interacted with the phosphatase SHP1 to inhibit Bruton tyrosine kinas (BTK)-mediated FAO in sepsis. Our findings expand the understanding of FAO dysfunction in sepsis and reveal TREM2 as a critical regulator of FAO, which may provide a promising target for the clinical treatment of sepsis.

Authors

Siqi Ming, Xingyu Li, Qiang Xiao, Siying Qu, Qiaohua Wang, Qiongyan Fang, Pingping Liang, Yating Xu, Jingwen Yang, Yongqiang Yang, Xi Huang, Yongjian Wu

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Abstract

Nonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease and highly prevalent worldwide. NASH is characterized by hepatic steatosis, inflammation, fibrosis and liver damage, which eventually results in liver dysfunction due to cirrhosis or hepatocellular carcinoma. However, the cellular and molecular mechanisms underlying NASH progression remain largely unknown. Here, we found an increase of Nr4a family of orphan nuclear receptors expression in intrahepatic T cells from mice with diet-induced NASH. Loss of Nr4a1 and Nr4a2 in T cell (dKO) ameliorated liver cell death and fibrosis, thereby mitigating liver dysfunction in NASH mice. dKO resulted in reduction of infiltrated macrophages and Th1/Th17 cells, whereas massive accumulation of T regulatory (Treg) cells in the liver of NASH mice. Combined single-cell RNA transcriptomic and TCR sequencing analysis revealed that intrahepatic dKO Tregs exhibited enhanced TIGIT and IL10 expression and were clonally expanded during NASH progression. Mechanistically, we found that dKO Tregs expressed high levels of Batf which promotes Treg cell proliferation and function upon TCR stimulation. Collectively, our findings not only provide an insight into the impact of intrahepatic Treg cells on NASH pathogenesis, but also suggest a therapeutic potential of targeting of Nr4a family to treat the disease.

Authors

Daisuke Aki, Taeko Hayakawa, Tanakorn Srirat, Shigeyuki Shichino, Minako Ito, Shin-Ichiroh Saitoh, Setsuko Mise-Omata, Akihiko Yoshimura

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Abstract

Dysfunctional adipose tissue is believed to promote the development of hepatic steatosis and systemic insulin resistance, but many of the mechanisms involved are still unclear. Lipin 1 catalyzes the conversion of phosphatidic acid to diacylglycerol (DAG), the penultimate step of triglyceride synthesis, which is essential for lipid storage. Herein we found that adipose tissue LPIN1 expression is decreased in people with obesity compared to lean subjects, and low LPIN1 expression correlated with multi-tissue insulin resistance and increased rates of hepatic de novo lipogenesis. Comprehensive metabolic and multi-omic phenotyping demonstrated that adipocyte-specific Lpin1–/– mice had a metabolically-unhealthy phenotype, including liver and skeletal muscle insulin resistance, hepatic steatosis, increased hepatic de novo lipogenesis, and transcriptomic signatures of metabolically associated steatohepatitis that was exacerbated by high-fat diets. We conclude that adipocyte lipin 1-mediated lipid storage is vital for preserving adipose tissue and systemic metabolic health, and its loss predisposes mice to metabolically associated steatohepatitis.

Authors

Andrew LaPoint, Jason M. Singer, Daniel Ferguson, Trevor M. Shew, M. Katie Renkemeyer, Hector H. Palacios, Rachael L. Field, Sireeesha Yerrathota, Roshan Kumari, Mahalakshmi Shankaran, Gordon I. Smith, Jun Yoshino, Mai He, Gary J. Patti, Marc K. Hellerstein, Samuel Klein, E. Matthew Morris, Jonathan R. Brestoff, Brian N. Finck, Andrew Lutkewitte

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Abstract

Epidermal stem cells control homeostasis and regeneration of skin and hair. In the hair follicle (HF) bulge of mammals, populations of slow-cycling stem cells regenerate the HF during cyclical rounds of anagen (growth), telogen (quiescence), and catagen (regression). Multipotent epidermal cells are also present in the HF above the bulge area, contributing to the formation and maintenance of sebaceous gland and upper and middle portions of the HF. Here, we report that the transcription factor Krox20 is enriched in an epidermal stem cell population located in the upper/ middle HF. Expression analyses and lineage tracing using inducible Krox20-CreERT showed that Krox20-lineage cells migrate out of this HF region and contribute to the formation of bulge in the HF, serving as ancestors of bulge stem cells. In vivo depletion of these cells arrests HF morphogenesis. This study identifies a novel marker for an epidermal stem cell population that is indispensable for hair homeostasis.

Authors

Elnaz Ghotbi, Edem Tchegnon, Zhiguo Chen, Stephen Li, Tracey Shipman, Yong Wang, Jenny Raman, Yumeng Zhang, Renee M. McKay, Chung-Ping Liao, Lu Q. Le

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Review Series - More

Substance Use Disorders

Series edited by Henry R. Kranzler

Substance use disorders are characterized by heavy, regular use of one or more psychoactive substances, such as alcohol, nicotine, opioids, cannabis, and stimulants, as well as the development of tolerance and loss of control over use, risk-taking behavior, and physiological dependence. Misuse of psychoactive substances constitutes a growing worldwide burden with broad-ranging health consequences. In this review series, curated by Dr. Henry R. Kranzler, reviews will provide detailed updates on studies of the genetics, biology, and evolving treatment of substance use disorders.

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