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Abstract
Glomerular inflammation and podocyte loss are the hallmarks of chronic kidney disease (CKD) progression. Understanding how podocytes and their microenvironment regulate inflammation is critical for developing effective therapies. In this study, we identified C-C chemokine ligand 5 (CCL5) as an inflammatory mediator elevated in injured podocytes, based on analyses of both human kidney biopsies and mouse models of CKD. We discovered that CCL5 exerts paradoxical effects in nephropathy: while it protects podocytes in vitro, it exacerbates glomerular injury in vivo. Recombinant CCL5 and podocyte-specific CCL5 overexpression promoted cell survival and reduced apoptosis in cultured podocytes. However, in Adriamycin-induced nephropathy, CCL5 worsened glomerular injury, increasing proteinuria, glomerulosclerosis, and podocyte loss. Bone marrow (BM) transplantation experiments revealed that CCL5 in BM-derived cells—not kidney-resident cells—drove disease progression. CCL5 deficiency in BM-derived cells conferred protection by increasing reparative M2 macrophages, whereas endogenous CCL5 promoted M1 polarization, inhibited M2 differentiation, and triggered M2-to-M1 transition. These findings demonstrate that while CCL5 supports podocyte survival, its expression in BM-derived cells promotes inflammatory macrophage phenotypes and glomerular injury. The harmful immune effects of CCL5 in BM-derived cells outweigh its podocyte-protective role, highlighting the importance of cell-targeted strategies to mitigate kidney damage.
Authors
Ika N. Kadariswantiningsih, Issei Okunaga, Kaho Yamasaki, Maulana A. Empitu, Hiroyuki Yamada, Shin-ichi Makino, Akitsu Hotta, Hideo Yagita, Masashi Aizawa, Ryo Koyama-Nasu, Motoko Y. Kimura, Narihito Tatsumoto, Katsuhiko Asanuma
Abstract
Matrix remodeling by metalloproteinases (MMPs) is essential for maintaining muscle homeostasis; however, their dysregulation can drive degenerative processes. By interrogating biopsy RNA-seq data, we show that MMP expression correlates with disease severity in facioscapulohumeral muscular dystrophy (FSHD). In the iDUX4pA FSHD mouse model, MMP levels also progressively increase in response to DUX4-induced muscle degeneration. Single-cell RNA-seq further identifies fibroadipogenic progenitors (FAPs) and macrophages as the primary sources of MMPs, particularly MMP2, MMP14, and MMP19, in dystrophic muscle. Treatment with the pan-MMP inhibitor Batimastat alleviates inflammation and fibrosis, improves muscle structure, and decreases the number of FAPs and infiltrating macrophages. These findings underscore the role of MMPs in driving muscle degeneration in FSHD, highlight MMPs as functional biomarkers of disease, and support MMP inhibitors as a DUX4-independent therapeutic approach to limit fibroadipogenesis and promote muscle regeneration.
Authors
Usuk Jung, Erdong Wei, Haseeb Ahsan, Ana Mitanoska, Kenric Chen, Michael Kyba, Darko Bosnakovski
Abstract
Bowel smooth muscle experiences mechanical stress constantly during normal function, and pathologic mechanical stressors in disease states. We tested the hypothesis that pathologic mechanical stress could alter transcription to induce smooth muscle phenotypic class switching. To test this hypothesis, primary human intestinal smooth muscle cells (HISMCs), seeded on electrospun aligned poly-ε-caprolactone nano-fibrous scaffolds, were subjected to pathologic, high frequency (1 Hz) uniaxial 3% cyclic stretch (loaded) or kept unloaded in culture for 6 hours. RNA sequencing, qRT-PCR, and quantitative immunohistochemistry defined loading-induced changes in gene expression. NicheNet predicted how differentially expressed genes might impact HISMCs and other bowel cells. These studies showed loading induced differential expression of 4537 HISMC genes. Loaded HISMCs had a less contractile phenotype, with increased expression of synthetic SMC genes, proinflammatory cytokines, and altered expression of axon guidance molecules, growth factors, and morphogens. Many differentially expressed genes encode secreted ligands that could act cell-autonomously on smooth muscle and on other cells in the bowel wall. These data show HISMCs undergo remarkably rapid phenotypic plasticity in response to mechanical stress that may convert contractile HISMCs into proliferative, fibroblast-like cells or proinflammatory cells. These mechanical stress-induced changes in HISMC gene expression may be relevant for human bowel disease.
Authors
Sharon M. Wolfson, Katherine Beigel, Sierra E. Anderson, Brooke Deal, Molly Weiner, Se-Hwan Lee, Deanne M. Taylor, Su Chin Heo, Robert O. Heuckeroth, Sohaib K. Hashmi
Abstract
Wiedemann-Steiner syndrome (WDSTS) is a rare genetic cause of intellectual disability that is primarily caused by heterozygous loss of function variants in the gene encoding the histone lysine methyltransferase 2A (KMT2A). Prior studies have shown successful postnatal amelioration of disease phenotypes for Rett, Rubinstein-Taybi and Kabuki syndromes, which are related Mendelian disorders of the epigenetic machinery. To explore whether the neurological phenotype in WDSTS is treatable in-utero, we created a mouse model carrying a loss of function variant placed between two loxP sites. Kmt2a+/LSL mice demonstrated core features of WDSTS including growth retardation, craniofacial abnormalities, and hypertrichosis as well as hippocampal memory defects. The neurological phenotypes were rescued upon restoration of KMT2A in-utero following breeding to a nestin-Cre. Together, our data provided a mouse model to explore the potential therapeutic window in WDSTS. Our work suggested that WDSTS has a window of opportunity extending at least until the mid-point of in-utero development, making WDSTS an ideal candidate for future therapeutic strategies.
Authors
Tinna Reynisdottir, Kimberley J. Anderson, Katrin Möller, Stefán Pétursson, Andrew Brinn, Katheryn P. Franklin, Juan Ouyang, Asbjorg O. Snorradottir, Cathleen M. Lutz, Aamir R. Zuberi, Valerie B. DeLeon, Hans T. Bjornsson
Abstract
Acute lower respiratory infections are the primary cause of global mortality in post-neonatal children. Most respiratory viruses primarily involve upper airway infection and inflammation, yet nasal responses are poorly characterized. Using a mouse model of human metapneumovirus (HMPV), we found viral burden was higher in nasal airways and exhibited delayed clearance. Despite high burden, there was low nasal expression of type I and III interferon (IFN). Single-cell RNA-sequencing (scRNA-seq) from HMPV-infected mice showed lower nasal interferon-stimulated gene (ISG) expression and nasal enrichment of genes negatively regulating IFN. scRNA-seq of COVID-19 patients confirmed lower ISG expression in upper airways. HMPV infection downregulated nasal expression of interferon regulatory factor-3, suggesting a mechanism for limited response. To rescue the quiescent environment, we administered type I or III IFN to upper airways early post-infection, leading to lower nasal HMPV titer and virus-specific CD8+ T-cell upregulation. Intranasal immunization adjuvanted with type I or III IFN improved immune response, reduced clinical disease, and enhanced viral clearance in HMPV and influenza infection. IFN adjuvant increased recruitment of dendritic cells, resident-memory T-cells, and neutralizing antibodies. These findings reveal locally suppressed IFN production contributes to a quiescent nasal immune landscape that delays viral clearance and impairs mucosal vaccine responses.
Authors
Jorna Sojati, Olivia B. Parks, Taylor Eddens, Jie Lan, Monika Johnson, John V. Williams
Abstract
The intestinal mucosal epithelium forms a barrier between luminal contents and the body. microRNAs (miRNAs) regulate mucosal homeostasis by controlling inflammatory responses and structural integrity. Here, we discovered a protective role for miR147 in intestinal inflammation using a miR147tdTomato reporter mouse. miR147 was enriched in the intestines, with the highest expression in the colonic epithelial cells at the luminal surface, with prominent expression in differentiated enterocytes. Mice with general or intestinal epithelial deletion of miR147 showed increased intestinal inflammation and diminished mucosal healing during colitis. RNA sequencing of miR147-deficient cells showed dysregulated immune signaling, with upregulated pro-inflammatory cytokine pathways and reduced type I interferon responses and revealed Ndufa4 as a likely miR147 target. Ndufa4, a mitochondrial protein regulating energy metabolism and inflammation, is elevated at the crypt base, inversely correlating with miR147. Mice lacking the miR147 binding site in Ndufa4’s 3′ untranslated region phenocopied miR147-deficient mice during colitis. Spatial and single-cell transcriptomic analyses in murine and human colons showed mutually exclusive miR147 and Ndufa4 expression, consistent with a regulatory relationship in epithelial differentiation and metabolism. These findings underscore miR147’s role in intestinal homeostasis and mucosal healing, suggesting it as a therapeutic target for inflammatory bowel disease.
Authors
Agnieszka K. Czopik, Arash Dabiri, Chia-Hao Tung, Victoria Vaughn, Xiangsheng Huang, Jinlian Wang, Hui Li, Nicolas F. Moreno, Natalia V. Piwko, Katherine Figarella, Hongfang Liu, Zhongming Zhao, Xiaoyi Yuan, Holger K. Eltzschig
Abstract
Fibroblast Growth Factor Receptors (FGFRs) are tyrosine kinase receptors critical for organogenesis and tissue maintenance, including in the adrenal gland. Here we delineate the role of FGFR2 in the morphogenesis, maintenance and function of the adrenal cortex with a focus on the zona Glomerulosa (zG). zG-specific Fgfr2 deletion (Fgfr2-cKO) resulted in impaired zG cell identity, proliferation and transdifferentiation into zona Fasciculata (zF) cells during postnatal development. In adult mice, induced deletion of Fgfr2 led to loss of mature zG cell identity, highlighting the importance of FGFR2 for the maintenance of a differentiated zG state. Strikingly, Fgfr2-cKO was sufficient to fully abrogate β-Catenin-induced zG hyperplasia and to reduce aldosterone levels. Finally, short-term treatment with pan-FGFR small molecule inhibitors suppressed aldosterone production in both wild-type and β-Catenin gain-of-function mice. These results demonstrate a critical role for FGFR signaling in adrenal morphogenesis, maintenance and function and suggest that targeting FGFR signaling may benefit patients with aldosterone excess and/or adrenal hyperplasia.
Authors
Vasileios Chortis, Dulanjalee Kariyawasam, Mesut Berber, Nick A. Guagliardo, Sining Leng, Betul Haykir, Claudio Ribeiro, Manasvi S. Shah, Emanuele Pignatti, Brenna Jorgensen, Lindsey Gaston, Paula Q. Barrett, Diana L. Carlone, Kleiton Silva Borges, David T. Breault
Abstract
About one-third of neonatal seizures do not respond to the first-line anticonvulsant phenobarbital, which activates phasic inhibition and whose effectiveness decreases over time. Whether enhancing tonic inhibition can treat refractory seizures or status epilepticus in neonates remains uncertain. We evaluated the effect of recurrent seizure-like events (SLE) on α5- and δ-GABAAR subunit expression and tonic inhibition in neonatal C57BL/6J mice (P6-P9, both sexes) using acute brain slices. We investigated the impact of THIP (gaboxadol) on neonatal behavioral seizures, neuronal apoptosis, and neurodegeneration in vivo. We found neonatal neocortical expression of α5- and δ-GABAA receptor (GABAAR) subunits. Blocking α5-GABAARs with L-655,708 did not affect acute neonatal SLE, whereas enhancing δ-GABAARs with THDOC, a neurosteroid, reduced them. The α5- and δ-GABAAR membrane expression increased after 8 hours of neonatal SLE, and correlated with increased δ-mediated conductance, but not α5-mediated one. Enhancing tonic inhibition was more effective in reducing recurrent neonatal SLE (8 hours) compared to early treatment. Increasing tonic inhibition reduced the duration, severity, and number of kainic acid-induced in vivo neonatal behavioral seizures without increasing neurodegeneration or apoptosis. We conclude that recurrent neonatal seizures increase tonic inhibition. Therefore, enhancing tonic inhibition may be a treatment strategy for prolonged neonatal status epilepticus.
Authors
Gage T. Liddiard, Gordon F. Buchanan, Mark L. Schultz, Joseph Glykys
Abstract
Glutaminolysis is enhanced in T cells of lupus patients and in follicular helper T (Tfh) cells, a critical subset of CD4+ T cells that provide help to autoreactive B cells, in lupus mice. Glutaminolysis inhibitors reduced lupus activity in association with a decreased frequency of Th17 cells in mice. Here, we thought to determine the role of glutaminolysis in murine Tfh cells. The pharmacological inhibition of glutaminolysis with DON reduced the expression of the critical costimulatory molecule ICOS on lupus Tfh cells, in association with a reduction of autoantibody production and B cell differentiation markers. Accordingly, profound transcriptomic and metabolic changes, including a reduction of glycolysis, were induced by DON in lupus Tfh cells, whereas healthy Tfh cells showed minor changes. The T cell-specific genetic inhibition of glutaminolysis largely phenocopied the effects of DON on Tfh cells and B cells in an autoimmune genetic background with minor changes in Tfh and B cells in healthy controls. Furthermore, we showed that T cell-specific glutaminolysis inhibition impaired T-dependent humoral responses in autoimmune mice as well as their Tfh response to a viral infection. Overall, these results suggest that lupus Tfh cells have a greater intrinsic requirement of glutaminolysis for their helper functions.
Authors
Seung-Chul Choi, Yong Ge, Milind V. Joshi, Damian Jimenez, Abigail Castellanos Garcia, Cassandra LaPlante, Lauren T. Padilla, Chaoyu Ma, Nu Zhang, Jeffrey C. Rathmell, Mansour Mohamadzadeh, Laurence Morel
Abstract
The phosphorylation of the ribosomal protein S6 (RPS6), was reported to be increased in myeloid cell subsets after stimulation with peanut extract in peanut-allergic individuals or with anti-IgE antibodies in both allergic and non-allergic donors. The mechanisms driving this increase of RPS6 phosphorylation (pS6) and its clinical impacts remain to be elucidated. Therefore, we investigated the mechanism of pS6 induction in plasmacytoid (pDCs) and conventional dendritic cells (cDCs) using whole blood stimulated with peanut extract or anti-IgE antibodies. This approach included in vitro basophil depletion and the application of receptor antagonists. Clinical associations with differential RPS6 phosphorylation were performed with data from a well-defined cohort of peanut-allergic individuals participating in the food intervention trial TINA. Our findings reveal an increase of pS6 in pDCs and cDCs via histamine receptor 2 (H2R) signalling after IgE-dependent basophil degranulation and histamine release. In adults – but not in children – RPS6 phosphorylation in cDCs was positively associated with food allergy severity, as determined by titrated oral food challenges. The association of RPS6 phosphorylation in cDCs with food allergy severity in an age-dependent manner suggests a novel functional mechanism, which may contribute to the course of food allergy, e.g. via increased antigen presentation.
Authors
Florent Fauchère, Andreas Thiel, Margitta Worm, Julian Braun
Abstract
Background. The SARS-CoV-2 virus has evolved subvariants since the emergence of the omicron variant in 2021. Whether these changes impact viral shedding and transmissibility is not known. Methods. POSITIVES is a prospective longitudinal cohort of individuals with mild SARS-CoV-2 infection. Ambulatory, immunocompetent participants who did not receive antivirals self-administered 6 anterior nasal swabs over 15 days. Samples were analyzed by qPCR to quantify viral RNA, semi-quantitative viral culture to detect shedding of replication-competent virus, and whole genome sequencing to classify subvariants. Our predictor of interest was omicron subvariant: BA.1x, BA.2x, BA.4/5x, XBB.x and JN.x. Outcomes included RNA levels and duration of shedding replication-competent virus. We additionally explored whether the duration and severity of symptom correlated with duration of viral shedding and whether symptoms are a valid marker for ending isolation. Results. The median peak nasal SARS-CoV-2 RNA (6.0-6.3 log10 RNA copies/mL), median days to peak RNA (4-5 days), median days to undetectable viral RNA (10-12 days) and median days to negative viral culture (3.5-6 days) was similar across omicron subvariants. Number and severity of symptoms were also similar. For all subvariants, a sizeable percentage (range 28.2-52.0%) shed replication-competent virus after fever resolution and improvement of symptoms. Conclusion. Despite ongoing viral evolution, key aspects of viral dynamics of SARS-CoV-2 infection, including the duration of shedding replication-competent virus, have not substantially changed across omicron subvariants. Replication-competent shedding of these subvariants is detected for a large proportion of people who meet criteria for ending isolation. Funding. This work was supported by the National Institutes of Health (NIH), the Massachusetts Consortium on Pathogen Readiness, and the Massachusetts General Hospital Department of Medicine.
Authors
Julie Boucau, Owen T. Glover, Caitlin Marino, Gregory E. Edelstein, Manish C. Choudhary, Yijia Li, Brooke M. Leeman, Zahra Reynolds, Karry Su, Dessie Tien, Chase B. Mandell, Eliza Passell, Andrew Alexandrescu, Emory Abar, Mamadou Barry, Dibya Ghimire, Tammy D. Vyas, Jatin M. Vyas, Jacob E. Lemieux, Jonathan Z. Li, Mark J. Siedner, Amy K. Barczak
Bcl6 reactivity is associated with a distinct immune landscape and spatial transcriptome in COVID-19
Abstract
The regulation of follicular (F) and germinal center (GC) immune reactivity in human lymph nodes (LNs), particularly during the acute stages of viral infection, remains poorly understood: We have analyzed lung-draining lymph nodes (LD-LNs) from COVID-19 autopsies using multiplex imaging and spatial transcriptomics to examine the immune landscape with respect to follicular immune reactivity. We identified three groups of donors based on the Bcl6 prevalence of their Reactive Follicles (RFs): RF-Bcl6no/low, RF-Bcl6int, and RF-Bcl6high. A distinct B/TFH immune landscape, associated with increased prevalence of proliferating B-cell and TFH-cell subsets, was found in RF-Bcl6high LD-LNs. The comparison between LD-LNs and subdiaphragmatic (SD) LNs from the same donor revealed a divergent Bcl6 expression between the two anatomical sites. LD-LN Bcl6 expression was also associated with a distinct spatial transcriptomic profile. TH1-associated genes/pathways (e.g., CXCR3, STAT5, TNF-signaling) were significantly up-regulated in RF-Bcl6no/low tissues, while the RF-Bcl6high tissues exhibited significant up-regulation of GC-promoting genes/pathways (e.g., CXCL13, B-cell receptor signaling). Our findings reveal a heterogeneous F/GC landscape in COVID-19 LD-LNs, highlighting specific molecular targets and pathways that could regulate human F/GC immune dynamics during acute viral infections.
Authors
Cloé Brenna, Bernat Bramon Mora, Kalliopi Ioannidou, Julien Bodelet, Mia L. Siebmanns, Simon Burgermeister, Spiros Georgakis, Michail Orfanakis, Yannick D. Muller, Nazanin Sédille, Matthew J. Feinstein, Jon W. Lomasney, Oliver Y. Chén, Giuseppe Pantaleo, Sabina Berezowska, Laurence de Leval, Raphael Gottardo, Constantinos Petrovas
Abstract
Cardiac hypertrophy is a common adaptation to cardiovascular stress and often a prelude to heart failure. We examined how S-palmitoylation of the small GTPase, Ras-related C3 botulinum toxin substrate 1 (Rac1), impacts cardiomyocyte stress signaling. Mutation of the cysteine-178 palmitoylation site impaired activation of Rac1 when overexpressed in cardiomyocytes. Cardiomyocyte-specific Rac1 conditional knock-in (Rac1cKI) mice expressing a Rac1C178S mutant protein exhibit normal cardiac structure-function but develop more severe cardiac hypertrophy in response to angiotensin-II (AngII) infusion, cardiomyocyte-specific overexpression of AngII type-I receptor (AT1R), and cardiac pressure overload. Moreover, pressure overload and AT1R overexpression evoked cardiac failure phenotypes in Rac1cKI mice not observed in controls. Mechanistically, Rac1cKI hearts and cardiomyocytes genetically-resistant to Rac1 S-palmitoylation have a profound increase in protein kinase A (PKA) substrate phosphorylation in response to acute β-adrenergic stimulation, as do Rac1cKI hearts subjected to chronic AngII treatment, AT1R overexpression, or pressure overload that correlates with more advanced heart failure phenotypes. This is not associated with increased PKA enzymatic activity, suggesting potential deficits in phosphatase activity at PKA-regulated phospho-sites. Taken together, this study suggests Rac1 S-palmitoylation dampens adrenergic drive and PKA-dependent modulation of the phospho-proteome in response to cardiovascular stress, revealing essential functions for S-acylated Rac1 in cardiac adaptation.
Authors
James P. Teuber, Rachel E. Scissors, Arasakumar Subramani, Nageswara Madamanchi, Matthew J. Brody
Abstract
Dravet syndrome (DS) is an early-onset epilepsy caused by loss of function mutations in the SCN1A gene, which encodes Nav1.1 channels that preferentially regulate activity of inhibitory neurons early in development. DS is associated with a high incidence of sudden unexpected death in epilepsy (SUDEP) by a mechanism that may involve respiratory failure. Evidence also shows that loss of Scn1a impaired activity of neurons in the retrotrapezoid nucleus (RTN) that regulate breathing in response to CO2/H+, suggesting breathing problems precede seizures and serve as a biomarker of SUDEP. Consistent with this, we showed that Scn1a+/- mice exhibited a blunted ventilatory response to CO2/H+ prior to overt seizure activity that worsened with disease progression. Later in development, some Scn1a+/- mice also showed a blunted ventilatory response to hypoxia. Importantly, the severity of respiratory problems correlated with mortality. We also found that pharmacological activation of Nav1.1 rescued activity deficits of RTN neurons in Scn1a+/- mice. We conclude that disordered breathing may be an early biomarker of SUDEP in DS, and at the cellular level loss of Scn1a disrupts RTN neurons by mechanisms involving disinhibition and pharmacological activation of Nav1.1 re-establish inhibitory control of RTN neurons and rescue activity deficits.
Authors
Brenda M, Milla, Eliandra Silva, Cleyton R. Sobrinho, Monica Strain, Daniel K. Mulkey
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease caused by low levels of SMN protein. Several therapeutic approaches boosting SMN are approved for human patients, delivering remarkable improvements in lifespan and symptoms. However, emerging phenotypes, including neurodevelopmental comorbidities, are being reported in some treated SMA patients, indicative of alterations in brain development. Here, using a mouse model of severe SMA, we revealed an underlying neurodevelopmental phenotype in SMA where prenatal SMN-dependent defects in translation drove disruptions in non-motile primary cilia across the central nervous system (CNS). Low levels of SMN caused widespread perturbations in translation at embryonic day (E) 14.5 targeting genes associated with primary cilia. The density of primary cilia in vivo, as well as cilial length in vitro, was significantly decreased in prenatal SMA mice. Proteomic analysis revealed downstream perturbations in primary cilia-regulated signalling pathways, including Wnt signalling. Cell proliferation was concomitantly reduced in the hippocampus of SMA mice. Prenatal transplacental therapeutic intervention with SMN-restoring risdiplam rescued primary cilia defects in SMA mouse embryos. Thus, SMN protein is required for normal cellular and molecular development of primary cilia in the CNS. Early, systemic treatment with SMN-restoring therapies can successfully target neurodevelopmental comorbidities in SMA.
Authors
Federica Genovese, Yu-Ting Huang, Anna A.L. Motyl, Martina Paganin, Gaurav Sharma, Ilaria Signoria, Deborah Donzel, Nicole C.H. Lai, Marie Pronot, Rachel A. Kline, Helena Chaytow, Kimberley J. Morris, Kiterie M.E. Faller, Thomas M. Wishart, Ewout J.N. Groen, Michael A. Cousin, Gabriella Viero, Thomas H. Gillingwater
Abstract
BACKGROUND. Active vitamin D metabolites, including 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D), have potent immunomodulatory effects that attenuate acute kidney injury (AKI) in animal models. METHODS. We conducted a phase 2, randomized, double-blind, multiple-dose, 3-arm clinical trial comparing oral calcifediol (25D), calcitriol (1,25D), and placebo among 150 critically ill adult patients at high-risk of moderate-to-severe AKI. The primary endpoint was a hierarchical composite of death, kidney replacement therapy (KRT), and kidney injury (baseline-adjusted mean change in serum creatinine), each assessed within 7 days following enrollment using a rank-based procedure. Secondary endpoints included new or progressive AKI and a composite of KRT or death. Hypercalcemia was the key safety endpoint. We also performed RNA sequencing on circulating CD14+ monocytes collected immediately prior to randomization and two days later. RESULTS. The global rank score for the primary endpoint was similar among calcifediol (n = 51) vs. placebo (n = 49) treated patients (P = 0.85) and for calcitriol (n = 50) versus placebo-treated patients (P = 0.58). Secondary endpoints also occurred at similar rates across groups. Hypercalcemia occurred in one patient in the calcifediol group (1.7%), one patient in the calcitriol group (2.0%), and none of the patients in the placebo group. Compared to placebo, calcitriol upregulated more individual genes and pathways in circulating monocytes than did calcifediol, including pathways involving interferon (IFN)-α, IFN-γ, oxidative phosphorylation, DNA repair, and heme metabolism. CONCLUSION. Treatment with calcifediol or calcitriol in critically ill adults upregulated multiple genes and pathways involving immunomodulation, DNA repair, and heme metabolism, but did not attenuate AKI. TRIAL REGISTRATION. ClinicalTrials.gov (NCT02962102). FUNDING. NIH/NIDDK grant K23DK106448 (Leaf) and NIH/NHLBI grant R01HL16687 (Kim)
Authors
David E. Leaf, Tushar Shenoy, Kevin Zinchuk, Shruti Gupta, Julie-Alexia Dias, Daniel Sanchez-Almanzar, Adit A. Ginde, Humra Athar, Changde Cheng, Tomoyoshi Tamura, Edy Y. Kim, Sushrut S. Waikar
Abstract
Impaired muscle regrowth in aging is underpinned by reduced pro-inflammatory macrophage function and subsequently impaired muscle cellular remodeling. Macrophage phenotype is metabolically controlled through TCA intermediate accumulation and activation of HIF1A. We hypothesized that transient hypoxia following disuse in old mice would enhance macrophage metabolic inflammatory function thereby improving muscle cellular remodeling and recovery. Old (20 months) and young adult mice (4 months) were exposed to acute (24h) normobaric hypoxia immediately following 14-days of hindlimb unloading and assessed during early re-ambulation (4- and 7-days) compared to age-matched controls. Treated aged mice had improved pro-inflammatory macrophage profiles, muscle cellular remodeling, and functional muscle recovery to the levels of young control mice. Likewise, young adult mice had enhanced muscle remodeling and functional recovery when treated with acute hypoxia. Treatment in aged mice restored the muscle molecular fingerprint and biochemical spectral patterns (Raman Spectroscopy) observed in young mice and strongly correlated to improved collagen remodeling. Finally, intramuscular delivery of hypoxia-treated macrophages recapitulated the muscle remodeling and recovery effects of whole-body hypoxic exposure in old mice. These results emphasize the role of pro-inflammatory macrophages during muscle regrowth in aging and highlight immunometabolic approaches as a route to improve muscle cellular dynamics and regrowth.
Authors
Zachary J. Fennel, Negar Kosari, Paul-Emile Bourrant, Elena M. Yee, Robert J. Castro, Anu S. Kurian, Jonathan Palmer, Morgan Christensen, Katsuhiko Funai, Ryan M. O'Connell, Anhong Zhou, Micah J. Drummond
Abstract
Authors
Jayanta Mondal, Patrick Nylund, Prit Benny Malgulwar, William E. Johnson, Jason T. Huse
Abstract
We conceived of a type of antitumor mechanism of action by which a soluble target in the tumor microenvironment, such as a tumor-driving growth factor, can be phagocytized along with cancer cells via antibody-dependent cellular phagocytosis (ADCP) using an antibody bispecific for the soluble target and a solid target overexpressed on the cancer cell surface. We explored this concept through engineering bispecific antibodies (BsAbs) co-targeting human epidermal growth factor receptor-2 (HER2) and vascular endothelial growth factor A (VEGFA) in an scFv-IgG format (VHS). We showed that the HER2-VEGFA BsAbs but not the parental antibodies alone or in combination induced co-phagocytosis of VEGFA and HER2-overexpressing cancer cells by tumor-associated macrophages via ADCP. In both immunocompromised and immunocompetent mice with aggressive tumors, the BsAbs demonstrated greater anti-metastasis activity and produced a greater survival benefit than the parental antibodies alone or in combination, in a manner dependent on Fcγ receptors on the macrophages. Our results provide proof of the concept that HER2-VEGFA BsAbs achieve enhanced antitumor activity by leveraging HER2 overexpressed on the cancer cell surface to induce co-phagocytosis of VEGFA. Our findings warrant clinical testing of the strategy to treat metastasis and recurrence of HER2-overexpressing solid tumors that respond to anti-VEGFA therapy.
Authors
Yang Lu, Songbo Qiu, Zhen Fan
Abstract
BACKGROUND. Understanding age-associated differences in acute and memory adaptive immunity to SARS-CoV-2 and how this contributes to more favorable outcomes in children is critically important. METHODS. We evaluated SARS-CoV-2–specific T cell, B cell, and antibody responses in 329 peripheral blood samples collected from non-hospitalized children, adolescents, and adults at three timepoints, including acute and memory timepoints. RESULTS. Most children produced robust CD4+ T cell responses during infection and developed memory CD4+ T cells; however, young children <4 years old often had undetectable CD4+ T cell responses compared to older children and adults. Young children also generated reduced frequencies of memory B cells; despite this, they mounted substantial and durable neutralizing antibody responses. CD4+ T cell responses in children were biased towards non-spike epitopes, especially in asymptomatic cases. Memory B cells in children were preferentially classical memory or, paradoxically, CXCR3+. CONCLUSION. These findings support the concept that the kinetics and composition of T and B cell responses shift across age groups and may be associated with milder COVID-19 outcomes in children.
Authors
L. Benjamin Hills, Numana Bhat, Jillian H. Hurst, Amber Myers, Thomas W. Burke, Micah T. McClain, Elizabeth Petzold, Alexandre T. Rotta, Nicholas A. Turner, Alba Grifoni, Daniela Weiskopf, Yvonne Dogariu, Genevieve G. Fouda, Sallie R. Permar, Alessandro Sette, Christopher W. Woods, Matthew S. Kelly, Shane Crotty
