In-Press Preview
Abstract
Dear Editor, We appreciate Albuquerque, et al.’s interest in our paper [1,2], who raised the concern that we did not accurately interpret the interaction test, noting that “one should directly compare the estimates (interaction test)” and “the authors concluded that the association was only present in the AA population, which is not compatible with their analysis.” We would like to clarify that our primary clinical question is whether ACE-I/ARB use is associated with the COVID-19 outcomes in each sub-group. We used stratified analysis to answer the question because when race/ethnicity serves as a non-specific proxy for numerous (confounding) factors, these can be (partially) controlled for through stratification [3]. Joint modeling of multiple groups is often used to gain power, but one needs to assume certain coherent distributions across different groups, which is not always true. Additionally, testing the interaction term is to assess association heterogeneity between groups, but it does not directly address whether the treatment is effective in each group. Specifically, we would like to elaborate on the following: 1) Our conclusion: “the use of ARB was associated with a significant reduction in in-hospital mortality among African American (AA) patients but not non-AA patients” was based on results from the stratified analysis. We reported that ARB in-hospital use was associated with reduced mortality in the AA stratum (OR=0.196; 95%CI:0.074-0.516; P=0.001) with statistical significance. On the other hand, the association in the non-AA stratum is not statistically significant (OR=0.687; 95%CI:0.427-1.106; P=0.122). As stated previously, our primary objective is to assess whether ACE-I/ARB use among AA patients is associated with COVID-19 mortality, rather than the difference between AA and non-AA patients. We were also aware that the estimated ORs across different stratum were not comparable as noted in [4-6]. 2) We performed the joint modeling of AA and non-AA patients as suggested by [6]. Here, ARB in-hospital use was associated with reduced mortality in entire study population (OR=0.560; 95%CI:0.371-0.846; P=0.006). The interaction term added to the model was not significant (95%CI:0.185-1.292; P=0.149). Interpreting interaction terms in logistic regression is complex and a significant interaction term in log-odds may not be significant in difference-in-differences for probability[7]. Furthermore, the assumption of the additive effects and imbalanced sample sizes could impact the inference. We believe these results and the interpretation are appropriate. We acknowledge that there are cases where comparing the interaction term in greater detail would be an important next step for understanding the association between COVID-19 mortality and race/ethnicity.
Authors
Shilong Li, Pei Wang, Li Li
Abstract
Studies using the nonhuman primate model of M. tuberculosis /Simian Immunodeficiency Virus co-infection have revealed protective CD4+ T cell-independent immune responses that suppress LTBI reactivation. In particular, chronic immune activation rather than the mere depletion of CD4+ T cells correlates with reactivation due to SIV co-infection. Here, we administered cART at 2 weeks post-SIV co-infection to study if restoration of CD4+ T cell immunity occurred more broadly, and if this prevented reactivation of LTBI compared to cART initiated at 4 weeks post-SIV. Earlier initiation of cART enhanced survival, led to better control of viral replication and reduced immune activation in the periphery and lung vasculature thereby reducing the rate of SIV-induced reactivation. We observed robust CD8+ T effector memory responses and significantly reduced macrophage turnover in the lung tissue. However, skewed CD4+ T effector memory responses persisted and new TB lesions formed post SIV co-infection. Thus, reactivation of LTBI is governed by very early events of SIV infection. Timing of cART is critical in mitigating chronic immune activation. The novelty of these findings mainly relates to the development of a robust animal model of human Mtb/HIV co-infection that allows the testing of underlying mechanisms.
Authors
Riti Sharan, Shashank R. Ganatra, Allison N. Bucsan, Journey Cole, Dhiraj K. Singh, Xavier Alvarez, Maya Gough, Cynthia Alvarez, Alyssa Blakley, Justin Ferdin, Rajesh Thippeshappa, Bindu Singh, Ruby Escobedo, Vinay Shivanna, Edward J. Dick, Jr., Shannan Hall-Ursone, Shabaana A. Khader, Smriti Mehra, Jyothi Rengarajan, Deepak Kaushal
Abstract
Mutations in Dyrk1b are associated with metabolic syndrome and non-alcoholic fatty liver disease in humans. Our investigations showed that DYRK1B levels are increased in the liver of patients with non-alcoholic liver steatohepatitis (NASH) and in mice fed with a high fat/sucrose diet. Increasing Dyrk1b levels in the mouse liver enhanced de novo lipogenesis (DNL), fatty-acid uptake, and TAG secretion and caused NASH and hyperlipidemia. Conversely, knockdown of Dyrk1b was protective against high-calorie induced hepatic steatosis and fibrosis and hyperlipidemia. Mechanistically, Dyrk1b increased DNL by activating mTORC2 in a kinase independent fashion. Accordingly, the Dyrk1b-induced NASH was fully rescued when mTORC2 was genetically disrupted. The elevated DNL was associated with increased plasma membrane sn-1,2-diacylglyerol levels and increased PKCε-mediated IRKT1150 phosphorylation, which resulted in impaired activation of hepatic insulin signaling and reduced hepatic glycogen storage. These findings provide new insights into the mechanisms that underlie Dyrk1b-induced hepatic lipogenesis and hepatic insulin resistance and identify Dyrk1b as a therapeutic target for NASH and insulin resistance in the liver.
Authors
Neha Bhat, Anand Narayanan, Mohsen Fathzadeh, Mario Kahn, Dongyan Zhang, Leigh Goedeke, Arpita Neogi, Rebecca L. Cardone, Richard G. Kibbey, Carlos Fernandez-Hernando, Henry N. Ginsberg, Dhanpat Jain, Gerald Shulman, Arya Mani
Abstract
The dysregulation of energy homeostasis in obesity involves multi-hormone resistance. Although leptin and insulin resistance have been well characterized, catecholamine resistance remains largely unexplored. Murine β3-adrenergic receptor expression in adipocytes is orders of magnitude higher compared to other isoforms. While resistant to classical desensitization pathways, its mRNA (Adrb3) and protein expression are dramatically downregulated after ligand exposure (homologous desensitization). β3-adrenergic receptor downregulation also occurs after high fat diet feeding, concurrent with catecholamine resistance and elevated inflammation. This downregulation is recapitulated in vitro by TNFα treatment (heterologous desensitization). Both homologous and heterologous desensitization of Adrb3 were triggered by induction of the pseudokinase TRIB1 downstream of the EPAC/RAP2A/PI-PLC pathway. TRIB1 in turn degraded the primary transcriptional activator of Adrb3, CEBPα. EPAC/RAP inhibition enhanced catecholamine-stimulated lipolysis and energy expenditure in obese mice. Moreover, adipose tissue expression of genes in this pathway correlated with body weight extremes in a cohort of genetically diverse mice, and with BMI in two independent cohorts of humans. These data implicate a new signaling axis that may explain reduced hormone-stimulated lipolysis in obesity and resistance to therapeutic interventions with β3-adrenergic receptor agonists.
Authors
Joseph M. Valentine, Maryam Ahmadian, Omer Keinan, Mohammad Abu-Odeh, Peng Zhao, Xin Zhou, Mark P. Keller, Hui Gao, Ruth T. Yu, Christopher Liddle, Michael Downes, Jin Zhang, Aldons J. Lusis, Alan D. Attie, Ronald M. Evans, Mikael Rydén, Alan R. Saltiel
Abstract
BACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans are currently beyond the reach of even the most modern ocular imaging modalities. METHODS. We present a compact fluorescence scanning laser ophthalmoscope (TPEF-SLO) and spectrally resolved images of the human retina based on two-photon excitation (TPE) with near-infrared (IR) light. A custom Er:fiber laser with integrated pulse selection, along with intelligent post-processing of data, enables excitation with low laser power and precise measurement of weak signals. RESULTS. We demonstrate spectrally resolved TPE fundus images of human subjects. Comparison of TPE data between human and mouse models of retinal diseases revealed similarity with mouse models that rapidly accumulate bisretinoid condensation products. Thus, visual cycle intermediates and toxic byproducts of this metabolic pathway can be measured and quantified by TPE imaging. CONCLUSION. Our work establishes a TPE instrument and measurement method for noninvasive metabolic assessment of the human retina. This approach opens the possibility for monitoring eye diseases in the earliest stages before structural damage to the retina occurs. FUNDING. NIH, Research to Prevent Blindness, Foundation for Polish Science, European Regional Development Fund, Polish National Agency for Academic Exchange and Polish Ministry of Science and Higher Education.
Authors
Jakub Boguslawski, Grazyna Palczewska, Slawomir Tomczewski, Jadwiga Milkiewicz, Piotr Kasprzycki, Dorota Stachowiak, Katarzyna Komar, Marcin J. Marzejon, Bartosz L. Sikorski, Arkadiusz Hudzikowski, Aleksander Głuszek, Zbigniew Łaszczych, Karol Karnowski, Grzegorz Soboń, Krzysztof Palczewski, Maciej Wojtkowski
Abstract
Autophagy selectively degrades aggregation-prone misfolded proteins caused by defective cellular proteostasis. However, the complexity of autophagy may prevent the full appreciation of how its modulation could be used as a therapeutic strategy in disease management. Here we define a molecular pathway through which recombinant interleukin-1 receptor antagonist (IL-1Ra, anakinra) affects cellular proteostasis independently from the IL-1 receptor (IL-1R1). Anakinra promoted H2O2-driven autophagy through a xenobiotic sensing pathway involving the aryl hydrocarbon receptor that, activated through the indoleamine 2,3-dioxygenase 1-kynurenine pathway, transcriptionally activates NADPH Oxidase 4 independent of the IL-1R1. By coupling the mitochondrial redox balance to autophagy, anakinra improved the dysregulated proteostasis network in murine and human cystic fibrosis. We anticipate that anakinra may represent a therapeutic option in addition to its IL-1R1 dependent anti-inflammatory properties by acting at the intersection of mitochondrial oxidative stress and autophagy with the capacity to restore conditions in which defective proteostasis leads to human disease.
Authors
Frank L. van de Veerdonk, Giorgia Renga, Marilena Pariano, Marina M. Bellet, Giuseppe Servillo, Francesca Fallarino, Antonella De Luca, Rossana G. Iannitti, Danilo Piobbico, Marco Gargaro, Giorgia Manni, Fiorella D’Onofrio, Claudia Stincardini, Luigi Sforna, Monica Borghi, Marilena Castelli, Stefania Pieroni, Vasileios Oikonomou, Valeria R. Villella, Matteo Puccetti, Stefano Giovagnoli, Roberta Galarini, Carolina Barola, Luigi Maiuri, Della-Fazia Maria Agnese, Barbara Cellini, Vincenzo Talesa, Charles A. Dinarello, Claudio Costantini, Luigina Romani
Abstract
Functional gastrointestinal disorders (FGIDs) have prominent sex differences in incidence, symptoms, and treatment response that are not well understood. Androgens are steroid hormones present at much higher levels in males than females and could be involved in these differences. In adults with irritable bowel syndrome (IBS), a FGID that affects 5-10% of the population worldwide, we found that free testosterone levels were lower than those in healthy controls and inversely correlated with symptom severity. To determine how this diminished androgen signaling could contribute to bowel dysfunction, we depleted gonadal androgens in adult mice and found that this caused a profound deficit in gastrointestinal transit. Restoring a single androgen hormone was sufficient to rescue this deficit, suggesting that circulating androgens are essential for normal bowel motility in vivo. To determine the site of action, we probed androgen receptor expression in the intestine and discovered, unexpectedly, that a large subset of enteric neurons became androgen-responsive upon puberty. Androgen signaling to these neurons was required for normal colonic motility in adult mice. Taken together, these observations establish a role for gonadal androgens in the neural regulation of bowel function and link altered androgen levels with a common digestive disorder.
Authors
Daniella Rastelli, Ariel Robinson, Valentina N. Lagomarsino, Lynley T. Matthews, Rafla Hassan, Kristina Perez, William Dan, Peter D. Yim, Madison Mixer, Aleksandra Prochera, Amy Shepherd, Liang Sun, Kathryn Hall, Sarah Ballou, Anthony Lembo, Judy Nee, Meenakshi Rao
RSPO2/RANKL-LGR4 signaling regulates osteoclastic pre-metastatic niche formation and bone metastasis
Abstract
Therapeutics targeting osteoclasts are commonly used treatments for bone metastasis; however, whether and how osteoclasts regulate pre-metastatic niche and bone tropism is largely unknown. In this study, we report that osteoclast precursors (OPs) can function as a pre-metastatic niche component that facilitates breast cancer (BCa) bone metastasis at early stages. At the molecular level, unbiased GPCR ligand/agonist screening in BCa cells suggested that R-spondin 2 (RSPO2) and RANKL, through interacting with their receptor LGR4, promoted osteoclastic pre-metastatic niche formation and enhanced BCa bone metastasis. This was achieved by RSPO2/RANKL-LGR4 signal modulating WNT inhibitor DKK1 through Gαq and β-catenin signaling. DKK1 directly facilitated OP recruitment through suppressing its receptor low-density lipoprotein-related receptors 5 (LRP5) but not LRP6, upregulating Rnasek expression via inhibiting canonical WNT signaling. In clinical samples, RSPO2, LGR4 and DKK1 expression showed positive correlation with BCa bone metastasis. Furthermore, soluble LGR4 extracellular domain (ECD) protein, acting as a decoy receptor for RSPO2 and RANKL, significantly alleviated bone metastasis and osteolytic lesions in mouse bone metastasis model. These findings provide unique insights into the functional role of OPs as key components of pre-metastatic niche for BCa bone metastasis, indicate RSPO2/RANKL-LGR4 signaling as a promising target for inhibiting BCa bone metastasis.
Authors
Zhiying Yue, Xin Niu, Zengjin Yuan, Qin Qin, Wenhao Jiang, Liang He, Jingduo Gao, Yi Ding, Yanxi Liu, Ziwei Xu, Zhenxi Li, Zhengfeng Yang, Rong Li, Xiwen Xue, Yankun Gao, Fei Yue, Xiang H.-F. Zhang, Guohong Hu, Yi Wang, Yi Li, Geng Chen, Stefan Siwko, Alison Gartland, Ning Wang, Jianru Xiao, Mingyao Liu, Jian Luo
Abstract
Ulcerating skin lesions are manifestations of human ISG15 deficiency, a type I interferonopathy. However, chronic inflammation may not be their exclusive cause. We describe two siblings with recurrent skin ulcers that healed with scar formation upon corticosteroid treatment. Both had a homozygous nonsense mutation in the ISG15 gene, leading to unstable ISG15 protein lacking the functional domain. We characterized ISG15-/- dermal fibroblasts, HaCaT keratinocytes, and human induced pluripotent stem cell-derived vascular endothelial cells. ISG15-deficient cells exhibited the expected hyperinflammatory phenotype, but also dysregulated expression of molecules critical for connective tissue and epidermis integrity, including reduced collagens and adhesion molecules, but increased matrix metalloproteases. ISG15-/- fibroblasts exhibited elevated ROS levels and reduced ROS scavenger expression. As opposed to hyperinflammation, defective collagen and integrin synthesis was not rescued by conjugation-deficient ISG15. Cell migration was retarded in ISG15-/- fibroblasts and HaCaT keratinocytes, but normalized under ruxolitinib treatment. Desmosome density was reduced in an ISG15-/- 3D epidermis model. Additionally, there were loose architecture and reduced collagen and desmoglein expression, which could be reversed by treatment with ruxolitinib/doxycycline/TGF-β1. These results reveal critical roles of ISG15 in maintaining cell migration and epidermis and connective tissue homeostasis, whereby the latter likely requires its conjugation to yet unidentified targets.
Authors
Muhammad Nasir Hayat Malik, Syed F. Hassnain Waqas, Jana Zeitvogel, Jingyuan Cheng, Robert Geffers, Zeinab Abu-Elbaha Gouda, Ahmed Mahrous Elsaman, Ahmed R. Radwan, Matthias Schefzyk, Peter Braubach, Bernd Auber, Ruth Olmer, Mathias Müsken, Lennart M. Roesner, Gisa Gerold, Sven Schuchardt, Sylvia Merkert, Ulrich Martin, Felix Meissner, Thomas Werfel, Frank Pessler
Abstract
Memory B cells (MBC) can provide a recall response able to supplement waning antibodies with an affinity-matured response better able to neutralise variant viruses. We studied a cohort of elderly care home residents and younger staff (median age 87yrs and 56yrs respectively) who had survived COVID-19 outbreaks with only mild/asymptomatic infection. The cohort was selected to enrich for a high proportion who had lost neutralising antibodies (nAb), to specifically investigate the reserve immunity from SARS-CoV-2-specific MBC in this setting. Class-switched spike and RBD-tetramer-binding MBC persisted five months post-mild/asymptomatic SARS-CoV-2 infection, irrespective of age. The majority of spike/RBD-specific MBC had a classical phenotype but activated memory B cells, that may indicate ongoing antigenic stimulation or inflammation, were expanded in the elderly. Spike/RBD-specific MBC remained detectable in the majority who had lost nAb, although at lower frequencies and with a reduced IgG/IgA isotype ratio. Functional spike/S1/RBD-specific recall was also detectable by ELISpot in some who had lost nAb, but was significantly impaired in the elderly. Our findings demonstrate a reserve of SARS-CoV-2-specific MBC persists beyond loss of nAb, but highlight the need for careful monitoring of functional defects in spike/RBD-specific B cell immunity in the elderly.
Authors
Anna Jeffery-Smith, Alice R. Burton, Sabela Lens, Chloe Rees-Spear, Jessica Davies, Monika Patel, Robin Gopal, Luke Muir, Felicity Aiano, Katie J. Doores, J. Yimmy Chow, Shamez N. Ladhani, Maria Zambon, Laura E. McCoy, Mala K. Maini.
No posts were found with this tag.
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)