The homeostasis of immunoglobulin G (IgG) is maintained by the neonatal Fc receptor, FcRn. Consequently, antagonism of FcRn to reduce endogenous IgG levels is an emerging strategy for treating antibody-mediated autoimmune disorders using either FcRn-specific antibodies or an engineered Fc fragment. For certain FcRn-specific antibodies, this approach has resulted in reductions in the levels of serum albumin, the other major ligand transported by FcRn. Cellular and molecular analyses of a panel of FcRn antagonists have been carried out to elucidate the mechanisms leading to their differential effects on albumin homeostasis. These analyses have identified two processes underlying decreases in albumin levels during FcRn blockade: increased degradation of FcRn and competition between antagonist and albumin for FcRn binding. These findings have potential implications for the design of drugs to modulate FcRn function.
Guanglong Ma, Andrew R. Crowley, Liesbeth Heyndrickx, Ilse Rogiers, Eef Parthoens, Jolien Van Santbergen, Raimund J. Ober, Vladimir Bobkov, Hans de Haard, Peter Ulrichts, Erik Hofman, Els Louagie, Bianca Balbino, E. Sally Ward
Activation of brown adipose tissue (BAT) thermogenesis increases energy expenditure and alleviates obesity. Here we discover that histone methyltransferase suppressor of variegation 4-20 homolog 2 (Suv420h2) expression parallels that of Ucp1 in brown and beige adipocytes and that Suv420h2 knockdown significantly reduces, whereas Suv420h2 overexpression significantly increases Ucp1 levels in brown adipocytes. Suv420h2 knockout (H2KO) mice exhibit impaired cold-induced thermogenesis and are prone to diet-induced obesity. In contrast, mice with specific overexpression of Suv420h2 in adipocytes display enhanced cold-induced thermogenesis and are resistant to diet-induced obesity. Further study shows that Suv420h2 catalyzes H4K20 trimethylation at eukaryotic translation initiation factor 4E-binding protein 1 (4e-bp1) promoter, leading to down-regulated expression of 4e-bp1, a negative regulator of the translation initiation complex. This in turn up-regulates PGC1α protein levels, which is associated with increased expression of thermogenic program. We conclude that Suv420h2 is a key regulator of brown/beige adipocyte development and thermogenesis.
Xin Cui, Qiang Cao, Fenfen Li, Jia Jing, Zhixue liu, Xiaosong Yang, Gary J. Schwartz, Liqing Yu, Huidong Shi, Hang shi, Bingzhong Xue
Clinical trials delivering high doses of adeno-associated viruses (AAVs) expressing truncated dystrophin molecules (micro-dystrophins) are underway for individuals with Duchenne muscular dystrophy (DMD). We examined the efficiency and efficacy of this strategy with four micro-dystrophin constructs (three in clinical trials and a variant of the largest clinical construct), in a severe mouse model of DMD, using doses of AAV comparable to those used in the clinical trials. We achieved high levels of micro-dystrophin expression in striated muscle with cardiac expression ~10 fold higher than that observed in skeletal muscle. Significant, albeit incomplete, correction of the skeletal muscle disease was observed. Surprisingly, a lethal acceleration of cardiac disease progression occurred with two of the micro-dystrophins. The detrimental impact on the heart appears to be caused by the high levels of micro-dystrophin resulting in variable competition (dependent on the design of the micro-dystrophin) between micro-dystrophin and utrophin at the cardiomyocyte membrane. There may also be a contribution from an overloading of protein degradation. The significance of these observations for patients currently being treated with AAV-micro-dystrophin therapies is unclear since the levels of expression being achieved in the DMD hearts are unknown. However, it suggests that micro-dystrophin treatments need to avoid excessively high levels of expression in the heart and cardiac function should be carefully monitored in these patients.
Cora C. Hart, Young il Lee, Jun Xie, Guangping Gao, Brian L. Lin, David W. Hammers, H. Lee Sweeney
Portal hypertension (PHTN) is a severe complication of liver cirrhosis and is associated with intrahepatic sinusoidal remodeling induced by sinusoidal resistance and angiogenesis. Collagen type IV (COL4), a major component of basement membrane, forms in liver sinusoids upon chronic liver injury. However, the role, the cellular source and expression regulation of COL4 in liver diseases is unknown. Here, we examined how COL4 is produced and how it regulates sinusoidal remodeling in fibrosis and PHTN. Human cirrhotic liver sample RNA-sequencing showed increased COL4 expression, which was further confirmed via immunofluorescence staining. scRNA-sequencing identified liver sinusoidal endothelial cells (LSECs) as the predominant source of COL4 upregulation in mouse fibrotic liver. In addition, COL4 was upregulated in a tumor necrosis factor α–nuclear factor–κB dependent manner through an epigenetic mechanism in liver sinusoidal endothelial cells in vitro. Indeed, by utilizing a CRISPRi-dCas9-KRAB-mediated epigenome editing approach, epigenetic repression of the enhancer-promoter interaction showed silencing of COL4 gene expression. LSEC-specific COL4 gene mutation or repression in vivo abrogated sinusoidal resistance and angiogenesis, which thereby alleviated sinusoidal remodeling and PHTN. Our findings reveal that LSECs promote sinusoidal remodeling and PHTN during liver fibrosis through COL4 deposition.
Can Gan, Usman Yaqoob, Jianwen Lu, Man Xie, Abid A. Anwar, Nidhi Jalan-Sakrikar, Sofia Jerez, Tejasav Sehrawat, Amaia Navarro-Corcuera, Enis Kostallari, Nawras W. Habash, Sheng Cao, Vijay H. Shah
A systems analysis was conducted to determine the potential molecular mechanisms underlying differential immunogenicity and protective efficacy results of a clinical trial of the radiation-attenuated whole sporozoite PfSPZ Vaccine in African infants. Innate immune activation and myeloid signatures at pre-vaccination baseline correlated with protection from Pf parasitemia in placebo controls. These same signatures were associated with susceptibility to parasitemia among infants who received the highest and most protective PfSPZ Vaccine dose. Machine learning identified spliceosome, proteosome, and resting dendritic cell signatures as pre-vaccination features predictive of protection after highest-dose PfSPZ vaccination, whereas baseline CSP-specific IgG predicted non-protection. Pre-vaccination innate inflammatory and myeloid signatures were associated with higher sporozoite-specific IgG Ab response but undetectable PfSPZ-specific CD8+ T-cell responses post-vaccination. Consistent with these human data, innate stimulation in vivo conferred protection against infection by sporozoite injection in malaria-naïve mice while diminishing the CD8+ T-cell response to radiation-attenuated sporozoites. These data suggest a dichotomous role of innate stimulation for malaria protection and induction of protective immunity of whole-sporozoite malaria vaccines. The uncoupling of vaccine-induced protective immunity achieved by Abs from more protective CD8+ T cell responses suggest that PfSPZ Vaccine efficacy in malaria-endemic settings may be constrained by opposing antigen presentation pathways.
Leetah Senkpeil, Jyoti Bhardwaj, Morgan R. Little, Prasida Holla, Aditi Upadhye, Elizabeth M. Fusco, Phillip A. Swanson II, Ryan E. Wiegand, Michael D. Macklin, Kevin Bi, Barbara J. Flynn, Ayako Yamamoto, Erik L. Gaskin, D. Noah Sather, Adrian L. Oblak, Edward Simpson, Hongyu Gao, W. Nicholas Haining, Kathleen B. Yates, Xiaowen Liu, Tooba Murshedkar, Thomas L. Richie, B. Kim Lee Sim, Kephas Otieno, Simon Kariuki, Xiaoling Xuei, Yunlong Liu, Rafael B. Polidoro, Stephen L. Hoffman, Martina Oneko, Laura C. Steinhardt, Nathan W. Schmidt, Robert A. Seder, Tuan M. Tran
Fetuses with growth restriction (FGR) have an early activation of hepatic glucose production (HGP), a hallmark of type 2 diabetes (T2D). Here we used fetal hepatic catheterization to directly measure HGP and substrate flux in an FGR sheep model. We hypothesized that FGR fetuses would have increased hepatic lactate and amino acid uptake to support increased HGP. Indeed, FGR compared to normal (CON) fetuses had increased HGP and activation of gluconeogenic genes. Unexpectedly, hepatic pyruvate output was increased while hepatic lactate and gluconeogenic amino acid uptake rates were decreased in FGR fetal liver. Hepatic oxygen consumption and total substrate uptake rates were lower. In FGR liver tissue, metabolite abundance, 13C-metabolite labeling, enzyme activity, and gene expression support decreased pyruvate oxidation and increased lactate production. Isolated hepatocytes from FGR fetuses had greater intrinsic capacity for lactate-fueled glucose production. FGR livers also had lower energy (ATP) and redox state (NADH:NAD+). Thus, reduced hepatic oxidative metabolism may make carbons available for increased HGP but also produces nutrient and energetic stress in FGR fetal liver. Intrinsic programming of these pathways regulating HGP in the FGR fetus may underlie increased HGP and T2D risk postnatally.
Laura D. Brown, Paul J. Rozance, Dong Wang, Evren C. Eroglu, Randall B. Wilkening, Ashley Solmonson, Stephanie R. Wesolowski
Manganese is an essential yet potentially toxic metal. Initially reported in 2012, mutations in SLC30A10 are the first known inherited cause of manganese excess. SLC30A10 is an apical membrane protein that exports manganese from hepatocytes into bile and from enterocytes into the lumen of the gastrointestinal tract. SLC30A10 deficiency results in impaired gastrointestinal manganese excretion, leading to manganese excess, neurologic deficits, liver cirrhosis, polycythemia, and erythropoietin excess. Neurologic and liver disease are attributed to manganese toxicity. Polycythemia is attributed to erythropoietin excess. The goal of this study was to determine the basis of erythropoietin excess in SLC30A10 deficiency. Here we demonstrate that transcription factors hypoxia-inducible factor 1a (Hif1a) and 2a (Hif2a), key mediators of the cellular response to hypoxia, are both upregulated in livers of Slc30a10-deficient mice. Hepatic Hif2a deficiency corrected erythropoietin expression and polycythemia and attenuated aberrant hepatic gene expression in Slc30a10-deficient mice, while hepatic Hif1a deficiency had no discernible impact. Hepatic Hif2a deficiency also attenuated manganese excess, although the underlying cause of this is not clear at this time. Overall, our results indicate that hepatic HIF2 is a key determinant of pathophysiology in SLC30A10 deficiency and expand our understanding of the contribution of HIFs to human disease.
Milankumar Prajapati, Jared Z. Zhang, Lauren Chiu, Grace S. Chong, Courtney J. Mercadante, Heather L. Kowalski, Bradley S. Delaney, Jessica A Anderson, Shuling Guo, Mariam Aghajan, Thomas B. Bartnikas
Chronic kidney disease (CKD) causes an accumulation of uremic metabolites that negatively impact skeletal muscle function. Tryptophan-derived uremic metabolites are agonists of the aryl hydrocarbon receptor (AHR) which has been shown to be activated in the blood of CKD patients. This study investigated the role of the AHR in skeletal muscle pathology of CKD. Compared to control participants with normal kidney function, AHR-dependent gene expression (CYP1A1 and CYP1B1) was significantly upregulated in skeletal muscle of patients with CKD (P=0.032) and the magnitude of AHR activation was inversely correlated with mitochondrial respiration (P<0.001). In mice with CKD, muscle mitochondrial oxidative phosphorylation (OXPHOS) was significantly impaired and strongly correlated with both the serum level of tryptophan-derived uremic metabolites and AHR activation. Muscle-specific deletion of the AHR significantly improved mitochondrial OXPHOS in male mice with the greatest uremic toxicity (CKD+probenecid) and abolished the relationship between uremic metabolites and OXPHOS. The uremic metabolite-AHR-mitochondrial axis in skeletal muscle was further confirmed using muscle-specific AHR knockdown in C57BL6J that harbour a high-affinity AHR allele, as well as ectopic viral expression of constitutively active mutant AHR in mice with normal renal function. Notably, OXPHOS changes in AHRmKO mice were only present when mitochondria were fueled by carbohydrates. Further analyses revealed that AHR activation in mice led to significant increases in Pdk4 expression (P<0.05) and phosphorylation of pyruvate dehydrogenase enzyme (P<0.05). These findings establish a uremic metabolite-AHR-Pdk4 axis in skeletal muscle that governs mitochondrial deficits in carbohydrate oxidation during CKD.
Trace Thome, Nicholas A. Vugman, Lauren E. Stone, Keon Wimberly, Salvatore T. Scali, Terence E. Ryan
BACKGROUND Persistent cough and dyspnea are prominent features of post-acute sequelae of SARS-CoV-2 (also termed ’Long COVID’); however, physiologic measures and clinical features associated with these pulmonary symptoms remain poorly defined. Using longitudinal pulmonary function testing (PFTs) and CT imaging, this study aimed to identify the characteristics and determinants of pulmonary Long COVID. METHODS This single-center retrospective study included 1,097 patients with clinically defined Long COVID characterized by persistent pulmonary symptoms (dyspnea, cough, and chest discomfort) lasting for ≥1 month after resolution of primary COVID infection. RESULTS After exclusion, a total of 929 patients with post-COVID pulmonary symptoms and PFTs were stratified diffusion impairment and restriction as measured by percent predicted diffusion capacity for carbon monoxide (DLCO) and total lung capacity (TLC). Dyspnea was the predominant symptom in the cohort (78%) and had similar prevalence regardless of degree of diffusion impairment or restriction. Longitudinal evaluation revealed diffusion impairment (DLCO ≤80%) and pulmonary restriction (TLC ≤80%) in 51% of the cohort overall (n=479). In multivariable logistic regression analysis (adjusted odds ratio; aOR, 95% confidence interval [CI]), invasive mechanical ventilation during primary infection conferred the greatest increased odds of developing pulmonary Long COVID with diffusion impairment and restriction (aOR=10.9 [4.09-28.6]). Finally, a sub-analysis of CT imaging identified radiographic evidence of fibrosis in this patient population. CONCLUSIONS Longitudinal PFT measurements in patients with prolonged pulmonary symptoms after SARS-CoV-2 infection revealed persistent diffusion impaired restriction as a key feature of pulmonary Long COVID. These results emphasize the importance of incorporating PFTs into routine clinical practice for evaluation of patients with prolonged pulmonary symptoms after resolution of SARS-CoV-2. Subsequent clinical trials should leverage combined symptomatic and quantitative PFT measurements for more targeted enrollment of pulmonary Long COVID patients. FUNDING This work was supported by the National Institute of Allergy and Infectious Diseases (AI156898, K08AI129705), the National Heart, Lung, and Blood Institute (HL153113, OTA21-015E, HL149944), and the COVID-19 Urgent Research Response Fund established by the Hugh Kaul Precision Medicine Network at the University of Alabama at Birmingham.
Michael John Patton, Donald Benson, Sarah W. Robison, Dhaval Raval, Morgan L. Locy, Kinner Patel, Scott Grumley, Emily B. Levitan, Peter Morris, Matthew Might, Amit Gaggar, Nathaniel Erdmann
Mesenchymal stem cells (MSCs) have demonstrated potent immunomodulatory properties that have shown promise in the treatment of autoimmune diseases, including rheumatoid arthritis (RA). However, the inherent heterogeneity of MSCs triggered conflicting therapeutic outcomes, raising safety concerns and limiting their clinical application. This study aimed to investigate the potential of extracellular vesicles derived from human gingival mesenchymal stem cells (GMSC-EVs) as a therapeutic strategy for RA. Through in vivo experiments using an experimental RA model, our results demonstrated that GMSC-EVs selectively homed to inflamed joints and recovered Treg and Th17 cells balance, resulting in the reduction of arthritis progression. Our investigations also uncovered miR-148a-3p as a critical contributor to the Treg/Th17 balance modulation via IKKB/NF-κB signaling orchestrated by GMSC-EVs, which was subsequently validated in a model of human xenograft versus host disease (xGvHD). Furthermore, we successfully developed a humanized animal model by utilizing synovial fibroblasts obtained from patients with RA (RASFs). We found that GMSC-EVs impeded the invasiveness of RASFs and minimized cartilage destruction, indicating their potential therapeutic efficacy in the context of RA patients. Overall, the unique characteristics, including reduced immunogenicity, simplified administration, and inherent ability to target inflamed tissues, position GMSC-EVs as a viable alternative for RA and other autoimmune diseases.
Jingrong Chen, Xiaoyi Shi, Yanan Deng, Junlong Dang, Yan Liu, Jun Zhao, Liang Rongzhen, Donglan Zeng, Wenbin Wu, Yiding Xiong, Jia Yuan, Ye Chen, Julie Wang, Weidong Lin, Xiangfang Chen, Weishan Huang, Nancy Olsen, Yunfeng Pan, Qing-Ling Fu, Song Guo Zheng
Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal cancer and is characterized by an unfavorable prognosis. To elucidate the distinct molecular alterations in ESCC and investigate therapeutic targets, we performed a comprehensive analysis of transcriptomic, proteomic, and phosphoproteomic data derived from 60 paired treatment-naive ESCC and adjacent non-tumor tissue samples. Additionally, we conducted a correlation analysis to describe the regulatory relationship between transcriptomic and proteomic processes, revealing alterations in key metabolic pathways. Unsupervised clustering analysis of the proteomic data stratified ESCC patients into three subtypes with different molecular characteristics and clinical outcomes. Notably, subtype III exhibited the worst prognosis and enrichment in proteins associated with malignant processes, including glycolysis and DNA repair pathways. Furthermore, translocase of inner mitochondrial membrane domain containing 1 (TIMMDC1) was validated as a potential prognostic molecule for ESCC. Moreover, integrated kinase-substrate network analysis using the phosphoproteome nominated candidate kinases as potential targets. In vitro and in vivo experiments further confirmed casein kinase II subunit alpha (CSNK2A1) as a potential kinase target for ESCC. These underlying data represent a valuable resource for researchers, which may provide better insights into the biology and treatment of ESCC.
Dengyun Zhao, Yaping Guo, Huifang Wei, Xuechao Jia, Yafei Zhi, Guiliang He, Wenna Nie, Limeng Huang, Penglei Wang, Kyle Vaughn Laster, Zhicai Liu, Jinwu Wang, Mee-Hyun Lee, Zigang Dong, Kangdong Liu
Mechanisms underlying maintenance of pathological vascular hypermuscularization are poorly delineated. Herein, we investigated retention of smooth muscle cells (SMCs) coating normally unmuscularized distal pulmonary arterioles in pulmonary hypertension (PH) mediated by chronic hypoxia ± Sugen 5416, and reversal of this pathology. With hypoxia in mice or culture, lung endothelial cells (ECs) upregulated hypoxia-inducible factor (Hif)-1a and 2a which induce platelet-derived growth factor-B (PDGF-B), and these factors reduced to normoxic levels with re-normoxia. Re-normoxia reversed hypoxia-induced pulmonary vascular remodeling, but with EC HIFα over-expression during re-normoxia, pathological changes persisted. Conversely, after establishment of distal muscularization and PH, EC-specific deletion of Hif1a, Hif2a, or Pdgfb induced reversal. In human idiopathic pulmonary artery hypertension, HIF1A, HIF2A, PDGFB and autophagy-mediating gene products, including Beclin1, were upregulated in pulmonary artery SMCs and/or lung lysates. Furthermore, in mice, hypoxia-induced EC-derived PDGF-B upregulated Beclin1 in distal arteriole SMCs, and after distal muscularization was established, re-normoxia, EC Pdgfb deletion or treatment with STI571 (which inhibits PDGF receptors) downregulated SMC Beclin1 and other autophagy products. Finally, SMC-specific Becn1 deletion induced apoptosis, reversing distal muscularization and PH mediated by hypoxia ± Sugen 5416. Thus, chronic hypoxia induction of HIFα-to-PDGF-B axis in ECs is required for non-cell autonomous Beclin1-mediated survival of pathological distal arteriole SMCs.
Fatima Z. Saddouk, Andrew P. Kuzemczak, Junichi Saito, Daniel M. Greif
NKX2-5 is a member of the homeobox-containing transcription factors critical in regulating tissue differentiation in development. Here, we report a role for NKX2-5 in vascular smooth muscle cell phenotypic modulation in vitro and in vascular remodelling in vivo. NKX2-5 is up-regulated in scleroderma (SSc) patients with pulmonary arterial hypertension. Suppression of NKX2-5 expression in smooth muscle cells, halted vascular smooth muscle proliferation and migration, enhanced contractility and blocked the expression of the extracellular matrix genes. Conversely, overexpression of NKX2-5 suppressed the expression of contractile genes (ACTA2, TAGLN, CNN1) and enhanced the expression of matrix genes (COL1) in vascular smooth muscle cells. In vivo, conditional deletion of NKX2-5 attenuated blood vessel remodelling and halted the progression to hypertension in the mouse chronic hypoxia mouse model. This study revealed that signals related to injury such as serum and low confluence, which induce NKX2-5 expression in cultured cells, is potentiated by TGFβ and further enhanced by hypoxia. The effect of TGFβ was sensitive to ERK5 and PI3K inhibition. Our data suggest a pivotal role for NKX2-5 in the phenotypic modulation of smooth muscle cells during pathological vascular remodelling and provide proof of concept for therapeutic targeting of NKX2-5 in vasculopathies.
Ioannis Papaioannou, Athina Dritsoula, Ping Kang, Reshma S. Baliga, Sarah L. Trinder, Emma Cook, Shiwen Xu, Adrian Hobbs, Christopher P. Denton, David J. Abraham, Markella Ponticos
Dysregulated lipid homeostasis is emerging as a potential cause of neurodegenerative disorders. However, evidence of errors in lipid homeostasis as a pathogenic mechanism of neurodegeneration remains limited. Here, we show that cerebellar neurodegeneration caused by Sorting Nexin 14 (SNX14) deficiency is associated with lipid homeostasis defects. Recent studies indicate that SNX14 is an inter-organelle lipid transfer protein that regulates lipid transport, lipid droplet (LD) biogenesis, and fatty acid desaturation, suggesting that human SNX14 deficiency belongs to an expanding class of cerebellar neurodegenerative disorders caused by altered cellular lipid homeostasis. To test this hypothesis, we generated a mouse model that recapitulates human SNX14 deficiency at a genetic and phenotypic level. We demonstrate that cerebellar Purkinje cells (PCs) are selectively vulnerable to SNX14 deficiency while forebrain regions preserve their neuronal content. Ultrastructure and lipidomic studies reveal widespread lipid storage and metabolism defects in SNX14 deficient mice. However, pre-degenerating SNX14 deficient cerebella show a unique accumulation of acylcarnitines and depletion of triglycerides. Furthermore, defects in LD content and telolysosome enlargement in pre-degenerating PCs, suggest lipotoxicity as a pathogenic mechanism of SNX14 deficiency. Our work shows a selective cerebellar vulnerability to altered lipid homeostasis and provides a mouse model for future therapeutic studies.
Yijing Zhou, Vanessa B. Sanchez, Peining Xu, Thomas Roule, Marco Flores-Mendez, Brianna Ciesielski, Donna Yoo, Hiab Teshome, Teresa Jimenez, Shibo Liu, Mike Henne, Tim O’Brien, Ye He, Clementina Mesaros, Naiara Akizu
Background. Upper body obesity (UBO) results in insulin resistance with regards to free fatty acid (FFA) release; how this differs by fat depot and sex between UBO and lean adults is unknown. We tested the hypothesis that insulin suppression of FFA release from the splanchnic bed, leg fat and upper body non-splanchnic (UBNS) adipose tissue would be impaired in UBO. Methods. Fourteen UBO (7 men, 7 women) and 14 healthy, normal weight (7 men, 7 women) volunteers participated in studies that included femoral artery, femoral vein and hepatic vein catheterization. We then measured leg and splanchnic plasma flow as well as FFA kinetics (using isotopic tracers) under overnight fasting, low- and high-dose insulin infusion using the insulin clamp technique. Results. We found the expected insulin resistance in UBO; the most quantitatively important difference between UBO and lean adults was greater FFA release from UBNS adipose tissue when plasma insulin concentrations are in the post-prandial, physiological range. There were obesity, but not sex differences in the regulation of splanchnic FFA release and sex differences in the regulation of leg FFA release. Conclusion. Reversing the defects in insulin-regulated UBNS adipose tissue FFA release would have the greatest impact on systemic FFA abnormalities in UBO. Trial Registration: (not applicable) Funding: These studies were supported by grants DK45343 and DK40484 from the U.S. Public Health Service, and the Novo Nordic Foundation (grant numbers NNF18OC0031804 and NNF16OC0021406) and the Independent Research Fund Denmark (grant number 8020-00420B).
Søren Nielsen, Michael D. Jensen
Allogeneic hematopoietic stem cell transplantation (aHSCT) can cure patients with otherwise fatal leukemias and lymphomas. However, the benefits of aHSCT are limited by graft-versus-host disease (GVHD). Minnelide, a water-soluble analog of triptolide, has demonstrated potent anti-inflammatory and anti-tumor activity in several pre-clinical models and has proven both safe and efficacious in clinical trials for advanced gastro-intestinal malignancies. Here, we tested the effectiveness of Minnelide in preventing acute GVHD as compared to cyclophosphamide post-aHSCT (PTCy). Strikingly, we found Minnelide improved survival, weight loss and clinical scores in an MHC-mismatched model of aHSCT. These benefits were also apparent in minor MHC-matched aHSCT and xenogeneic HSCT models. Minnelide was comparable to PTCy in terms of survival, GVHD clinical score and colonic length. Notably, in addition to decreased donor T cell infiltration early post-HSCT, several regulatory cell populations including Tregs, ILC2s and MDSCs in the colon were increased which together may account for Minnelide’s GVHD suppression post-HSCT. Importantly, Minnelide GVHD prevention was accompanied by preservation of graft-versus-tumor (GVT) activity. As Minnelide possesses anti-AML activity and is being applied in clinical trials, together with the present findings, we conclude that this compound might provide a new approach for AML patients undergoing aHSCT.
Sabrina N. Copsel, Vanessa T. Garrido, Henry Barreras, Cameron S. Bader, Brent Pfeiffer, Beatriz Mateo-Victoriano, Dietlinde Wolf, Miguel Gallardo, Sophie Paczesny, Krishna V. Komanduri, Cara L. Benjamin, Alejandro Villarino, Ashok K. Saluja, Robert B. Levy
Background. Disease of the aorta varies from atherosclerosis to aneurysms with complications including rupture, dissection, and poorly characterized limited tears. We studied limited tears without any mural hematoma, termed intimomedial tears to gain insight into aortic vulnerability to excessive wall stresses. Our premise is that minimal injuries in aortas with sufficient medial resilience to prevent tear progression correspond to initial mechanisms leading to complete structural failure in aortas with significantly compromised medial resilience. Methods. Intimomedial tears were macroscopically identified in 9 of 108 ascending aortas after surgery and analyzed by histology and immunofluorescence confocal microscopy. Results. Non-hemorrhagic, non atheromatous tears correlated with advanced aneurysmal disease and most lacked distinctive symptoms or radiological signs. Tears traversed the intima and part of the subjacent media, while the resultant defects were partially or completely filled with neointima characterized by differentiated smooth muscle cells, scattered leukocytes, dense fibrosis, and absent elastic laminae despite tropoelastin synthesis. Healed lesions contained organized fibrin at tear edges without evidence of plasma and erythrocyte extravasation or lipid accumulation. Conclusion. These findings suggest a multiphasic model of aortic wall failure in which primary lesions of intimomedial tears either heal if the media is sufficiently resilient or progress as dissection or rupture by medial delamination and tear completion, respectively. Moreover, mural incorporation of thrombus and cellular responses to injury, two historically important concepts in atheroma pathogenesis, contribute to vessel wall repair with adequate conduit function but even together are not sufficient to induce atherosclerosis. Funding. R01-HL146723, R01-HL168473, and Yale Department of Surgery.
Abdulrahman H.M. Hassab, David J. Hur, Prashanth Vallabhajosyula, George Tellides, Roland Assi
Recent studies have uncovered that non-coding sequence variants may relate to Axenfeld-Rieger syndrome (ARS), a rare developmental anomaly with genetic heterogeneity. However, how these genomic regions are functionally and structurally associated with ARS is still unclear. In this study, we performed genome-wide linkage analysis and whole-genome sequencing in a Chinese ARS family and identified a heterozygous deletion of about 570 kb (termed LOH-1) in the intergenic sequence between PITX2 and FAM241A. Knockout of LOH-1 homologous sequences caused ARS phenotypes in mice. RNA-seq and RT-qPCR revealed a significant reduction in Pitx2 gene expression in LOH-1–/– mice, while Foxc1 expression remained unchanged. ChIP-seq and bioinformatics analysis identified a potential enhancer region (LOH-E1) within LOH-1. Deletion of LOH-E1 led to a significant downregulation of the PITX2 gene. Mechanistically, we found a sequence (hg38 chr4:111,399,594-111,399,691) which is on LOH-E1 could regulate PITX2 by binding to RAD21, a critical component of the cohesin complex. Knockdown of RAD21 resulted in reduced PITX2 expression. Collectively, our findings indicate that a potential enhancer sequence which is within LOH-1 may regulate PITX2 expression remotely through cohesin-mediated loop domains, leading to ARS when absent. 2
Yizheng Jiang, Yu Peng, Qi Tian, Zhe Cheng, Bei Feng, Junping Hu, Lu Xia, Hui Guo, Kun Xia, Liang Zhou, Zhengmao Hu
The viral kinetics of documented SARS-CoV-2 infections exhibit a high degree of inter-individual variability. We identified six distinct viral shedding patterns, which differed according to peak viral load, duration, expansion rate and clearance rate, by clustering data from 768 infections in the National Basketball Association cohort. Omicron variant infections in previously vaccinated individuals generally led to lower cumulative shedding levels of SARS-CoV-2 than other scenarios. We then developed a mechanistic mathematical model that recapitulated 1510 observed viral trajectories, including viral rebound and cases of reinfection. Lower peak viral loads were explained by a more rapid and sustained transition of susceptible cells to a refractory state during infection, as well as an earlier and more potent late, cytolytic immune response. Our results suggest that viral elimination occurs more rapidly during omicron infection, following vaccination, and following re-infection due to enhanced innate and acquired immune responses. Because viral load has been linked with COVID-19 severity and transmission risk, our model provides a framework for understanding the wide range of observed SARS-CoV-2 infection outcomes.
Katherine Owens, Shadisadat Esmaeili, Joshua Schiffer
Diagnostic challenges continue to impede development of effective therapies for successful management of alcohol-associated hepatitis (AH), thus creating an unmet need to identify and develop non-invasive biomarkers for AH. In murine models of ethanol-induced liver injury, complement activation contributes to hepatic inflammation and injury. Therefore, we hypothesized that complement proteins could be rational diagnostic/prognostic biomarkers in AH. Here, we performed a comparative analysis of data derived from the human hepatic and serum proteome to identify and characterize complement protein signatures in severe AH (sAH). The quantity of multiple complement proteins was perturbed in liver and serum proteome of patients with sAH. Multiple complement proteins differentiated patients with sAH from those with alcohol cirrhosis (AC), alcohol use disorder (AUD) and healthy controls (HCs). Notably, serum collectin 11 and C1q binding protein were strongly associated with sAH and exhibited good discriminatory performance amongst patients with sAH, AC, AUD, and HCs. Furthermore, complement component receptor 1-like protein (CR1L) was negatively associated with pro-inflammatory cytokines. Additionally, lower serum mannose-binding lectin associated serine protease 1 and coagulation factor II were associated with and independently predicted 90-day mortality. In summary, meta-analysis of proteomic profiles from liver and circulation revealed complement protein signatures of sAH, highlighting a complex perturbation of complement and identifying potential diagnostic and prognostic biomarkers for patients with sAH.
Moyinoluwa T. Taiwo, Emily Huang, Vai Pathak, Annette Bellar, Nicole Welch, Jaividhya Dasarathy, David Streem, Craig J. McClain, Mack C. Mitchell, Bruce A. Barton, Gyongyi Szabo, Srinivasan Dasarathy, Esperance A. Schaefer, Jay Luther, Le Z. Day, Xinshou Ouyang, Suyavaran Arumugam, Wajahat Z. Mehal, Jon M. Jacobs, Russell P. Goodman, Daniel M. Rotroff, Laura E. Nagy