Issue published August 1, 2022 Previous issue
- Volume 132, Issue 15
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On the cover: VEGF-C and Ang signaling pathway crosstalk in lymphangiogenesis
Korhonen et al. explore the mechanistic basis of Ang2 activity in lymphangiogenesis and report that Ang2/Tie/PI3K signaling is required for cell-surface expression of VEGFR3. The cover image shows overgrowth of dermal lymphatic vessels in a mouse model of oncogenic PI3K–driven lymphatic malformation, with immunofluorescent staining of VEGFR3 (purple), LYVE1 (lymphatic vessels, green), and PECAM-1 (blood vessels, gray). Image credit: Yan Zhang.
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Review Series
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Abstract
Cellular senescence is a hallmark of aging defined by stable exit from the cell cycle in response to cellular damage and stress. Senescent cells (SnCs) can develop a characteristic pathogenic senescence-associated secretory phenotype (SASP) that drives secondary senescence and disrupts tissue homeostasis, resulting in loss of tissue repair and regeneration. The use of transgenic mouse models in which SnCs can be genetically ablated has established a key role for SnCs in driving aging and age-related disease. Importantly, senotherapeutics have been developed to pharmacologically eliminate SnCs, termed senolytics, or suppress the SASP and other markers of senescence, termed senomorphics. Based on extensive preclinical studies as well as small clinical trials demonstrating the benefits of senotherapeutics, multiple clinical trials are under way. This Review discusses the role of SnCs in aging and age-related diseases, strategies to target SnCs, approaches to discover and develop senotherapeutics, and preclinical and clinical advances of senolytics.
Authors
Lei Zhang, Louise E. Pitcher, Matthew J. Yousefzadeh, Laura J. Niedernhofer, Paul D. Robbins, Yi Zhu
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Review
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Abstract
SARS-CoV-2–infected individuals may suffer a multi–organ system disorder known as “long COVID” or post-acute sequelae of SARS-CoV-2 infection (PASC). There are no standard treatments, the pathophysiology is unknown, and incidence varies by clinical phenotype. Acute COVID-19 correlates with biomarkers of systemic inflammation, hypercoagulability, and comorbidities that are less prominent in PASC. Macrovessel thrombosis, a hallmark of acute COVID-19, is less frequent in PASC. Female sex at birth is associated with reduced risk for acute COVID-19 progression, but with increased risk of PASC. Persistent microvascular endotheliopathy associated with cryptic SARS-CoV-2 tissue reservoirs has been implicated in PASC pathology. Autoantibodies, localized inflammation, and reactivation of latent pathogens may also be involved, potentially leading to microvascular thrombosis, as documented in multiple PASC tissues. Diagnostic assays illuminating possible therapeutic targets are discussed.
Authors
Jasimuddin Ahamed, Jeffrey Laurence
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Commentaries
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Abstract
Current paradigms of bone marrow failure (BMF) pathophysiology suggest that immune-mediated destruction of hematopoietic stem and progenitor cells (HSPCs) drives acquired aplastic anemia. In contrast, loss of HSPCs due to senescence and/or apoptosis causes BMF in inherited BMF syndromes. In this issue of the JCI, Casado and colleagues challenge this dichotomous conception by demonstrating that NK cell–dependent, immune-mediated hematopoietic suppression and HSPC clearance drive BMF in Fanconi anemia (FA). They show that genotoxic stress upregulates natural killer group 2 member D ligands (NKG2D-L) on FA HSPCs leading to NK cell cytotoxicity through NKG2D receptor activation. Inhibition of NKG2D–NKG2D-L interactions enhanced FA HSPC clonogenic potential and improved cytopenias in vivo. These results provide alternative targets for the development of immunosuppressive therapies to reduce HSPC loss and mitigate the risk of hematologic malignancies in FA.
Authors
Brian M. Dulmovits, Timothy S. Olson
×Abstract
Stroke is a leading cause of death and long-term disability. T cells have been extensively studied for their dual role in regulating immunity and inflammation following stroke. In this issue of the JCI, Cai, Shi, et al. demonstrated that CD8+ regulatory-like T cells (CD8+ TRLs) are one of the earliest lymphocyte subtypes to enter the brain after experimental ischemic stroke. Using a mouse model of stroke and comprehensive experimental approaches, the authors found that CD8+ TRLs reduced both brain damage and functional deficits in both young and aged mice. These unique early responding regulatory T cells may also play a role in a wide array of other T cell–mediated neurological disorders.
Authors
Juneyoung Lee, Louise D. McCullough
×Abstract
Hepatitis C virus (HCV) infection remains a worldwide public health issue despite direct-acting antivirals. A substantial proportion of infected individuals (15%–45%) spontaneously clear repeated HCV infections with genetically different viruses by generating broadly neutralizing antibodies (bNAbs). However, translating this response into an effective vaccine strategy has been unsuccessful. In this issue of the JCI, Frumento and colleagues report on their study of bNAb evolution longitudinally in convalescent individuals with repeated infections. Using pseudotyped viruses, well-characterized monoclonal antibodies, and complex modeling, the authors show that multiple exposures to antigenically related, antibody-sensitive viral envelope proteins induced potent bNAbs. This work provides valuable insight into the best strategies for developing HCV vaccines in the future that may successfully reproduce the immunity induced during natural exposures.
Authors
Bharath K. Sreekumar, Taha Y. Taha, Melanie Ott
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Research Articles
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Abstract
Fanconi anemia (FA) is the most prevalent inherited bone marrow failure (BMF) syndrome. Nevertheless, the pathophysiological mechanisms of BMF in FA have not been fully elucidated. Since FA cells are defective in DNA repair, we hypothesized that FA hematopoietic stem and progenitor cells (HSPCs) might express DNA damage–associated stress molecules such as natural killer group 2 member D ligands (NKG2D-Ls). These ligands could then interact with the activating NKG2D receptor expressed in cytotoxic NK or CD8+ T cells, which may result in progressive HSPC depletion. Our results indeed demonstrated upregulated levels of NKG2D-Ls in cultured FA fibroblasts and T cells, and these levels were further exacerbated by mitomycin C or formaldehyde. Notably, a high proportion of BM CD34+ HSPCs from patients with FA also expressed increased levels of NKG2D-Ls, which correlated inversely with the percentage of CD34+ cells in BM. Remarkably, the reduced clonogenic potential characteristic of FA HSPCs was improved by blocking NKG2D–NKG2D-L interactions. Moreover, the in vivo blockage of these interactions in a BMF FA mouse model ameliorated the anemia in these animals. Our study demonstrates the involvement of NKG2D–NKG2D-L interactions in FA HSPC functionality, suggesting an unexpected role of the immune system in the progressive BMF that is characteristic of FA.
Authors
José A. Casado, Antonio Valeri, Rebeca Sanchez-Domínguez, Paula Vela, Andrea López, Susana Navarro, Omaira Alberquilla, Helmut Hanenberg, Roser Pujol, José-Carlos Segovia, Jordi Minguillón, Jordi Surrallés, Cristina Díaz de Heredia, Julián Sevilla, Paula Rio, Juan A. Bueren
×Abstract
Acquired resistance is inevitable in non–small cell lung cancers (NSCLCs) treated with osimertinib (OSI), and the mechanisms are not well defined. The MERTK ligand GAS6 promoted downstream oncogenic signaling in EGFR-mutated (EGFRMT) NSCLC cells treated with OSI, suggesting a role for MERTK activation in OSI resistance. Indeed, treatment with MRX-2843, a first-in-class MERTK kinase inhibitor, resensitized GAS6-treated NSCLC cells to OSI. Both GAS6 and EGF stimulated downstream PI3K/AKT and MAPK/ERK signaling in parental cells, but only GAS6 activated these pathways in OSI-resistant (OSIR) derivative cell lines. Functionally, OSIR cells were more sensitive to MRX-2843 than parental cells, suggesting acquired dependence on MERTK signaling. Furthermore, MERTK and/or its ligands were dramatically upregulated in EGFRMT tumors after treatment with OSI in both xenograft models and patient samples, consistent with induction of autocrine/paracrine MERTK activation. Moreover, treatment with MRX-2843 in combination with OSI, but not OSI alone, provided durable suppression of tumor growth in vivo, even after treatment was stopped. These data identify MERTK as a driver of bypass signaling in treatment-naive and EGFRMT-OSIR NSCLC cells and predict that MRX-2843 and OSI combination therapy will provide clinical benefit in patients with EGFRMT NSCLC.
Authors
Dan Yan, Justus M. Huelse, Dmitri Kireev, Zikang Tan, Luxiao Chen, Subir Goyal, Xiaodong Wang, Stephen V. Frye, Madhusmita Behera, Frank Schneider, Suresh S. Ramalingam, Taofeek Owonikoko, H. Shelton Earp, Deborah DeRyckere, Douglas K. Graham
×Abstract
The encoding of noxious stimuli into action potential firing is largely mediated by nociceptive free nerve endings. Tissue inflammation, by changing the intrinsic properties of the nociceptive endings, leads to nociceptive hyperexcitability and thus to the development of inflammatory pain. Here, we showed that tissue inflammation–induced activation of the mammalian target of rapamycin complex 2 (mTORC2) triggers changes in the architecture of nociceptive terminals and leads to inflammatory pain. Pharmacological activation of mTORC2 induced elongation and branching of nociceptor peripheral endings and caused long-lasting pain hypersensitivity. Conversely, nociceptor-specific deletion of the mTORC2 regulatory protein rapamycin-insensitive companion of mTOR (Rictor) prevented inflammation-induced elongation and branching of cutaneous nociceptive fibers and attenuated inflammatory pain hypersensitivity. Computational modeling demonstrated that mTORC2-mediated structural changes in the nociceptive terminal tree are sufficient to increase the excitability of nociceptors. Targeting mTORC2 using a single injection of antisense oligonucleotide against Rictor provided long-lasting alleviation of inflammatory pain hypersensitivity. Collectively, we showed that tissue inflammation–induced activation of mTORC2 causes structural plasticity of nociceptive free nerve endings in the epidermis and inflammatory hyperalgesia, representing a therapeutic target for inflammatory pain.
Authors
Calvin Wong, Omer Barkai, Feng Wang, Carolina Thörn Perez, Shaya Lev, Weihua Cai, Shannon Tansley, Noosha Yousefpour, Mehdi Hooshmandi, Kevin C. Lister, Mariam Latif, A. Claudio Cuello, Masha Prager-Khoutorsky, Jeffrey S. Mogil, Philippe Séguéla, Yves De Koninck, Alfredo Ribeiro-da-Silva, Alexander M. Binshtok, Arkady Khoutorsky
×Abstract
Vascular endothelial growth factor C (VEGF-C) induces lymphangiogenesis via VEGF receptor 3 (VEGFR3), which is encoded by the most frequently mutated gene in human primary lymphedema. Angiopoietins (Angs) and their Tie receptors regulate lymphatic vessel development, and mutations of the ANGPT2 gene were recently found in human primary lymphedema. However, the mechanistic basis of Ang2 activity in lymphangiogenesis is not fully understood. Here, we used gene deletion, blocking Abs, transgene induction, and gene transfer to study how Ang2, its Tie2 receptor, and Tie1 regulate lymphatic vessels. We discovered that VEGF-C–induced Ang2 secretion from lymphatic endothelial cells (LECs) was involved in full Akt activation downstream of phosphoinositide 3 kinase (PI3K). Neonatal deletion of genes encoding the Tie receptors or Ang2 in LECs, or administration of an Ang2-blocking Ab decreased VEGFR3 presentation on LECs and inhibited lymphangiogenesis. A similar effect was observed in LECs upon deletion of the PI3K catalytic p110α subunit or with small-molecule inhibition of a constitutively active PI3K located downstream of Ang2. Deletion of Tie receptors or blockade of Ang2 decreased VEGF-C–induced lymphangiogenesis also in adult mice. Our results reveal an important crosstalk between the VEGF-C and Ang signaling pathways and suggest new avenues for therapeutic manipulation of lymphangiogenesis by targeting Ang2/Tie/PI3K signaling.
Authors
Emilia A. Korhonen, Aino Murtomäki, Sawan Kumar Jha, Andrey Anisimov, Anne Pink, Yan Zhang, Simon Stritt, Inam Liaqat, Lukas Stanczuk, Laura Alderfer, Zhiliang Sun, Emmi Kapiainen, Abhishek Singh, Ibrahim Sultan, Anni Lantta, Veli-Matti Leppänen, Lauri Eklund, Yulong He, Hellmut G. Augustin, Kari Vaahtomeri, Pipsa Saharinen, Taija Mäkinen, Kari Alitalo
×Abstract
Resistance to regeneration of insulin-producing pancreatic β cells is a fundamental challenge for type 1 and type 2 diabetes. Recently, small molecule inhibitors of the kinase DYRK1A have proven effective in inducing adult human β cells to proliferate, but their detailed mechanism of action is incompletely understood. We interrogated our human insulinoma and β cell transcriptomic databases seeking to understand why β cells in insulinomas proliferate, while normal β cells do not. This search reveals the DREAM complex as a central regulator of quiescence in human β cells. The DREAM complex consists of a module of transcriptionally repressive proteins that assemble in response to DYRK1A kinase activity, thereby inducing and maintaining cellular quiescence. In the absence of DYRK1A, DREAM subunits reassemble into the pro-proliferative MMB complex. Here, we demonstrate that small molecule DYRK1A inhibitors induce human β cells to replicate by converting the repressive DREAM complex to its pro-proliferative MMB conformation.
Authors
Peng Wang, Esra Karakose, Carmen Argmann, Huan Wang, Metodi Balev, Rachel I. Brody, Hembly G. Rivas, Xinyue Liu, Olivia Wood, Hongtao Liu, Lauryn Choleva, Dan Hasson, Emily Bernstein, Joao A. Paulo, Donald K. Scott, Luca Lambertini, James A. DeCaprio, Andrew F. Stewart
×Neuroprotection against ischemic stroke requires a specific class of early responder T cells in mice
Abstract
Immunomodulation holds therapeutic promise against brain injuries, but leveraging this approach requires a precise understanding of mechanisms. We report that CD8+CD122+CD49dlo T regulatory-like cells (CD8+ TRLs) are among the earliest lymphocytes to infiltrate mouse brains after ischemic stroke and temper inflammation; they also confer neuroprotection. TRL depletion worsened stroke outcomes, an effect reversed by CD8+ TRL reconstitution. The CXCR3/CXCL10 axis served as the brain-homing mechanism for CD8+ TRLs. Upon brain entry, CD8+ TRLs were reprogrammed to upregulate leukemia inhibitory factor (LIF) receptor, epidermal growth factor–like transforming growth factor (ETGF), and interleukin 10 (IL-10). LIF/LIF receptor interactions induced ETGF and IL-10 production in CD8+ TRLs. While IL-10 induction was important for the antiinflammatory effects of CD8+ TRLs, ETGF provided direct neuroprotection. Poststroke intravenous transfer of CD8+ TRLs reduced infarction, promoting long-term neurological recovery in young males or aged mice of both sexes. Thus, these unique CD8+ TRLs serve as early responders to rally defenses against stroke, offering fresh perspectives for clinical translation.
Authors
Wei Cai, Ligen Shi, Jingyan Zhao, Fei Xu, Connor Dufort, Qing Ye, Tuo Yang, Xuejiao Dai, Junxuan Lyu, Chenghao Jin, Hongjian Pu, Fang Yu, Sulaiman Hassan, Zeyu Sun, Wenting Zhang, T. Kevin Hitchens, Yejie Shi, Angus W. Thomson, Rehana K. Leak, Xiaoming Hu, Jun Chen
×Abstract
BACKGROUND Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has achieved remarkable clinical efficacy in metastatic cancers such as melanoma and cervical cancer (CC). Here, we explored the safety, feasibility, and preliminary tumor response and performed translational investigations of adjuvant immunotherapy using infusion of autogenous TILs (auto-TILs) following concurrent chemoradiotherapy (CCRT) in patients with CC who had locally advanced disease.METHODS Twenty-seven patients with CC with stage III–IV disease were recruited in this single-center, phase I study. TILs were isolated from lesions in the uterine cervix and generated under good manufacturing practice (GMP) conditions and then infused after CCRT plus i.m. IL-2 injections.RESULTS TILs from 20 of the 27 patients were successfully expanded, with a feasibility of 74.1%. Twelve patients received TILs following CCRT. Adverse events (AEs) were primarily attributable to CCRT. Only 1 (8.3%) patient experienced severe toxicity with a grade 3 hypersensitivity reaction after TIL infusion. No autoimmune AEs, such as pneumonitis, hepatitis, or myocarditis, occurred, and there were no treatment-related mortalities. Nine of 12 patients (75.0%) attained a complete response, with a disease control duration of 9–22 months. Translational investigation showed that the transcriptomic characteristics of the infused TIL products and some immune biomarkers in the tumor microenvironment and serum of patients with CC at baseline were correlated with the clinical response.CONCLUSION TIL-based ACT following CCRT was safe in an academic center setting, with potentially effective responses in patients with locally advanced CC. “Hot” inflammatory immune environments were beneficial to the clinical efficacy of TIL-based ACT as adjuvant therapy.TRIAL REGISTRATION ClinicalTrials.gov NCT04443296.FUNDING National Key R&D Program; Sci-Tech Key Program of the Guangzhou City Science Foundation; the Guangdong Province Sci-Tech International Key Program; the National Natural Science Foundation of China.
Authors
He Huang, Cai-ping Nie, Xiu-feng Liu, Bin Song, Jian-hui Yue, Jing-xiao Xu, Jia He, Kui Li, Yan-ling Feng, Ting Wan, Min Zheng, Yan-Na Zhang, Wei-Jun Ye, Jun-Dong Li, Yan-Fang Li, Jun-yun Li, Xin-Ping Cao, Zhi-min Liu, Xiao-shi Zhang, Qing Liu, Xi Zhang, Ji-Hong Liu, Jiang Li
×Abstract
Over the last 2 decades, omalizumab is the only anti-IgE antibody that has been approved for asthma and chronic spontaneous urticaria (CSU). Ligelizumab, a higher-affinity anti-IgE mAb and the only rival viable candidate in late-stage clinical trials, showed anti-CSU efficacy superior to that of omalizumab in phase IIb but not in phase III. This report features the antigenic-functional characteristics of UB-221, an anti-IgE mAb of a newer class that is distinct from omalizumab and ligelizumab. UB-221, in free form, bound abundantly to CD23-occupied IgE and, in oligomeric mAb-IgE complex forms, freely engaged CD23, while ligelizumab reacted limitedly and omalizumab stayed inert toward CD23; these observations are consistent with UB-221 outperforming ligelizumab and omalizumab in CD23-mediated downregulation of IgE production. UB-221 bound IgE with a strong affinity to prevent FcԑRI-mediated basophil activation and degranulation, exhibiting superior IgE-neutralizing activity to that of omalizumab. UB-221 and ligelizumab bound cellular IgE and effectively neutralized IgE in sera of patients with atopic dermatitis with equal strength, while omalizumab lagged behind. A single UB-221 dose administered to cynomolgus macaques and human IgE (ε, κ)–knockin mice could induce rapid, pronounced serum-IgE reduction. A single UB-221 dose administered to patients with CSU in a first-in-human trial exhibited durable disease symptom relief in parallel with a rapid reduction in serum free-IgE level.
Authors
Be-Sheng Kuo, Chao-Hung Li, Jiun-Bo Chen, Yu-Yu Shiung, Chia-Yu Chu, Chih-Hung Lee, Yaw-Jen Liu, Je-Hung Kuo, Cindy Hsu, Hsiao-Wen Su, Ywan-Feng Li, Annie Lai, Yueh-Feng Ho, Yi-Ning Cheng, Hong-Xuan Huang, Meng-Chung Lung, Ming-Syue Wu, Fu-Hong Yang, Chen-Han Lin, William Tseng, Jasper Yang, Chia-Yin Lin, Pei-Hua Tsai, Heng-Kwei Chang, Yi-Jen Wang, Techeng Chen, Shugene Lynn, Mei-June Liao, Chang Yi Wang
×Abstract
A prophylactic hepatitis C virus (HCV) vaccine that elicits neutralizing antibodies could be key to HCV eradication. However, the genetic and antigenic properties of HCV envelope (E1E2) proteins capable of inducing anti-HCV broadly neutralizing antibodies (bNAbs) in humans have not been defined. Here, we investigated the development of bNAbs in longitudinal plasma of HCV-infected persons with persistent infection or spontaneous clearance of multiple reinfections. By measuring plasma antibody neutralization of a heterologous virus panel, we found that the breadth and potency of the antibody response increased upon exposure to multiple genetically distinct infections and with longer duration of viremia. Greater genetic divergence between infecting strains was not associated with enhanced neutralizing breadth. Rather, repeated exposure to antigenically related, antibody-sensitive E1E2s was associated with potent bNAb induction. These data reveal that a prime-boost vaccine strategy with genetically distinct, antibody-sensitive viruses is a promising approach to inducing potent bNAbs in humans.
Authors
Nicole Frumento, Alexis Figueroa, Tingchang Wang, Muhammad N. Zahid, Shuyi Wang, Guido Massaccesi, Georgia Stavrakis, James E. Crowe Jr, Andrew I. Flyak, Hongkai Ji, Stuart C. Ray, George M. Shaw, Andrea L. Cox, Justin R. Bailey
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Abstract
Vessel co-option has been demonstrated to mediate colorectal cancer liver metastasis (CRCLM) resistance to anti-angiogenic therapy. The current mechanisms underlying vessel co-option have mainly focused on the "hijacker" tumor cells, whereas the function of the “hijackee” sinusoidal blood vessels has not been explored. Here, we found that the occurrence of vessel co-option in bevacizumab-resistant CRCLM xenografts was associated with increased expression of fibroblast activation protein alpha (FAPα) in the co-opted hepatic stellate cells (HSCs), which was dramatically attenuated in HSC-specific conditional Fap-knockout mice bearing CRCLM allografts. Mechanistically, bevacizumab treatment induced hypoxia to upregulate the expression of fibroblast growth factor-binding protein 1 (FGFBP1) in tumor cells. Gain- or loss-of-function experiments revealed that the bevacizumab-resistant tumor cell-derived FGFBP1 induced FAPα expression by enhancing the paracrine FGF2-FGFR1-ERK1/2-EGR1 signaling pathway in HSCs. FAPα promoted CXCL5 secretion in HSCs, which activated CXCR2 to promote the epithelial-mesenchymal transition of tumor cells and the recruitment of myeloid-derived suppressor cells. These findings were further validated in CRCLM patient-derived tumor tissues. Targeting FAPα+ HSCs effectively disrupted the co-opted sinusoidal blood vessels and overcame bevacizumab resistance. Our study highlights the role of FAPα+ HSCs in vessel co-option and provides an effective strategy to overcome the vessel co-option-mediated bevacizumab resistance.
Authors
Ming Qi, Shuran Fan, Maohua Huang, Jinghua Pan, Yong Li, Qun Miao, Wenyu Lyu, Xiaobo Li, Lijuan Deng, Shenghui Qiu, Tongzheng Liu, Weiqing Deng, Xiaodong Chu, Chang Jiang, Wenzhuo He, Liangping Xia, Yunlong Yang, Jian Hong, Qi Qi, Wenqian Yin, Xiangning Liu, Changzheng Shi, Minfeng Chen, Wencai Ye, Dongmei Zhang
Abstract
Accidental injury to the cardiac conduction system (CCS), a network of specialized cells embedded within the heart and indistinguishable from the surrounding heart muscle tissue, is a major complication in cardiac surgeries. Here, we addressed this unmet need by engineering targeted antibody-dye conjugates directed against CCS, allowing for the visualization of the CCS in vivo following a single intravenous injection in mice. These optical imaging tools showed high sensitivity, specificity, and resolution, with no adverse effects to CCS function. Further, with the goal of creating a viable prototype for human use, we generated a fully human monoclonal Fab, that similarly targets the CCS with high specificity. We demonstrate that, when conjugated to an alternative cargo, this Fab can also be used to modulate CCS biology in vivo providing a proof-of-principle for targeted cardiac therapeutics. Finally, in performing differential gene expression analyses of the entire murine CCS at single-cell resolution, we uncovered and validated a suite of additional cell surface markers that can be used to molecularly target the distinct subcomponents of the CCS, each prone to distinct life-threatening arrhythmias. These findings lay the foundation for translational approaches targeting the CCS for visualization and therapy in cardiothoracic surgery, cardiac imaging and arrhythmia management.
Authors
William R. Goodyer, Benjamin M. Beyersdorf, Lauren Duan, Nynke S. van den Berg, Sruthi Mantri, Francisco X. Galdos, Nazan Puluca, Jan W. Buikema, Soah Lee, Darren Salmi, Elise R. Robinson, Stephan Rogalla, Dillon P. Cogan, Chaitan Khosla, Eben L. Rosenthal, Sean M. Wu
Abstract
To understand how kidney donation leads to excess preeclampsia risk, we studied pregnant outbred mice with prior uninephrectomy and compared them to sham-treated littermates carrying both kidneys. During pregnancy, uninephrectomized mice failed to achieve physiological increase of glomerular filtration rate, and during late gestation developed hypertension, albuminuria, glomerular endothelial damage, and excess placental production of soluble fms-like tyrosine kinase 1 (sFLT1), an anti-angiogenic protein implicated in the pathogenesis of preeclampsia. Maternal hypertension in uninephrectomized mice was associated with low plasma volumes, increased rate of fetal resorption, impaired spiral artery remodeling and placental ischemia. To evaluate potential mechanisms, we studied plasma metabolite changes using mass spectrometry and noted that L-kynurenine, a metabolite of L-tryptophan, was upregulated ~3 fold during pregnancy when compared to pre-pregnant concentrations in the same animals, consistent with prior reports suggesting a protective role for L-kynurenine in placental health. However, uninephrectomized mice failed to upregulate L-kynurenine during pregnancy; furthermore, when uninephrectomized mice were fed L-kynurenine in drinking water throughout pregnancy, their preeclampsia-like state was rescued, including reversal of placental ischemia and normalization of sFLT1 levels. In aggregate, we provide a mechanistic basis for how impaired renal reserve and resulting failure to upregulate L-kynurenine during pregnancy can lead to impaired placentation, placental hypoperfusion, anti-angiogenic state and subsequent preeclampsia.
Authors
Vincent Dupont, Anders H. Berg, Michifumi Yamashita, Chengqun Huang, Ambart E. Covarrubias, Shafat Ali, Aleksandr Stotland, Jennifer E. Van Eyk, Belinda Jim, Ravi Thadhani, S. Ananth Karumanchi
Abstract
NVX-CoV2373 is an adjuvanted recombinant full-length SARS-CoV-2 spike trimer protein vaccine demonstrated to be protective against COVID-19 in efficacy trials. Here we demonstrate that vaccinated subjects made CD4+ T cell responses after one and two doses of NVX-CoV2373, and a subset of individuals made CD8+ T cell responses. Characterization of the vaccine-elicited CD8+ T cells demonstrated IFN𝛾 production. Characterization of the vaccine-elicited CD4+ T cells revealed both circulating T follicular helper cells (cTFH) and TH1 cells (IFN𝛾, TNFa, and IL-2) were detectable within 7 days of the primary immunization. Spike-specific CD4+ T cells were correlated with the magnitude of the later SARS-CoV-2 neutralizing antibody titers, indicating that robust generation of CD4+ T cells, capable of supporting humoral immune responses, may be a key characteristic of NVX-CoV2373 which utilizes Matrix-M™ adjuvant.
Authors
Carolyn Rydyznski Moderbacher, Christina J. Kim, Jose Mateus, Joyce S. Plested, Mingzhu Zhu, Shane Cloney-Clark, Daniela Weiskopf, Alessandro Sette, Louis Fries, Gregory Glenn, Shane Crotty
Abstract
Infantile (fetal and neonatal) megakaryocytes have a distinct phenotype consisting of hyperproliferation, limited morphogenesis, and low platelet production capacity. These properties contribute to clinical problems that include thrombocytopenia in neonates, delayed platelet engraftment in recipients of cord blood stem cell transplants, and inefficient ex vivo platelet production from pluripotent stem cell-derived megakaryocytes. The infantile phenotype results from deficiency of the actin-regulated coactivator, MKL1, which programs cytoskeletal changes driving morphogenesis. As a strategy to complement this molecular defect, we screened pathways with potential to affect MKL1 function and found that Dyrk1a kinase inhibition dramatically enhanced megakaryocyte morphogenesis in vitro and in vivo. Dyrk1 inhibitors rescued enlargement, polyploidization, and thrombopoiesis in human neonatal megakaryocytes. Megakaryocytes derived from induced pluripotent stem cells responded in a similar manner. Progenitors undergoing Dyrk1 inhibition demonstrated filamentous actin assembly, MKL1 nuclear translocation, and modulation of MKL1 target genes. Loss of function studies confirmed MKL1 involvement in this morphogenetic pathway. Ablim2, a stabilizer of filamentous actin, increased with Dyrk1 inhibition, and Ablim2 knockdown abrogated the actin, MKL1, and morphogenetic responses to Dyrk1 inhibition. These results thus delineate a pharmacologically tractable morphogenetic pathway whose manipulation may alleviate clinical problems associated with the limited thrombopoietic capacity of infantile megakaryocytes.
Authors
Kamaleldin E. Elagib, Ashton Brock, Cara M. Clementelli, Gohar Mosoyan, Lorrie L. Delehanty, Ranjit K. Sahu, Alexandra Pacheco-Benichou, Corinne Fruit, Thierry Besson, Stephan W. Morris, Koji Eto, Chintan Jobaliya, Deborah L. French, Paul Gadue, Sandeep Singh, Xinrui Shi, Fujun Qin, Robert Cornelison, Hui Li, Camelia Iancu-Rubin, Adam N. Goldfarb
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August 2022 JCI This Month
JCI This Month is a digest of the research, reviews, and other features published each month.
Review Series - More
Series edited by James L. Kirkland
Aging
Series edited by James L. Kirkland
Aging plays a central role in many chronic diseases affecting all systems of the body. Nine hallmarks of aging have been identified: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. This new review series on Aging closely examines how these hallmarks contribute to the initiation and progression of disease. Curated by series editor Dr. James Kirkland, topics span aging’s role in immune system function, cancer, cognitive decline and neurodegenerative disease, and metabolism. The reviews also discuss the latest developments in senotherapeutic strategies that destroy senescent cells, reverse senescence, or target specific aging hallmarks with a critical eye.
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Copyright © 2022 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)