The SNP rs755622 is associated with immune activation in glioblastoma

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Abstract

Intratumoral heterogeneity is a defining hallmark of glioblastoma, driving drug resistant and ultimately recurrence. Many somatic drivers of microenvironmental change have been shown to affect this heterogeneity and ultimately treatment response. However, little is known about how germline mutations effect the tumoral microenvironment. Here, we find that the single-nucleotide polymorphism (SNP) rs755622 in promoter of the cytokine macrophage migration inhibitory factor (MIF), is associated with increased leukocyte infiltration in glioblastoma. Furthermore, we identified an association between rs755622 and lactotransferrin expression, which could also be used as a biomarker for immune-infiltrated tumors. These findings demonstrate that a germline SNP in the promoter region of MIF may impact the immune microenvironment and further reveals a link between lactotransferrin and immune activation.

Authors

Tyler J. Alban, Matthew M. Grabowski, Balint Otvos, Defne Bayik, Wesley Wang, Ajay H. Zalavadia, Vladimir Makarav, Katie M. Troike, Mary McGraw, Anja Rabljenovic, Adam Lauko, Chase K.A. Neumann, Gustavo Roversi, Kristin A. Waite, Gino Cioffi, Nirav Patil, Thuy T. Tran, Kathleen McCortney, Alicia Steffens, C. Marcela Diaz-Montero, J. Mark Brown, Kathleen M. Egan, Craig Horbinski, Jill S. Barnholtz-Sloan, Prajwal Rajappa, Michael A. Vogelbaum, Richard Bucala, Timothy A. Chan, Manmeet S. Ahluwalia, Justin D. Lathia

Ablation of C-type natriuretic peptide/cGMP signaling in fibroblasts exacerbates adverse cardiac remodeling in mice

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Abstract

Excessive activation of cardiac fibroblasts (CFs) in response to injury provokes cardiac fibrosis, stiffness, and failure. The local mediators counter-regulating this response remain unclear. Exogenous C-type natriuretic peptide (CNP) exerted antifibrotic effects in preclinical models. To unravel the role of the endogenous hormone, we generated mice with fibroblast-restricted deletion (KO) of guanylyl cyclase-B (GC-B), the cGMP-synthesizing CNP receptor.CNP activated GC-B/cGMP signaling in human and murine CFs, preventing proliferative and promigratory effects of AngiotensinII (AngII) and TGF-β. Fibroblast-specific GC-B-KO mice showed enhanced fibrosis in response to AngII infusions. Moreover, after two weeks of mild pressure-overload induced by transverse aortic constriction (TAC), such KO mice had augmented cardiac fibrosis and hypertrophy, together with systolic and diastolic contractile dysfunction. This was associated with increased expression of the profibrotic genes collagen I, III and periostin. Notably, such responses to AngII and TAC were greater in female as compared to male KO mice. Enhanced AngII-induced CNP expression in female hearts and augmented GC-B expression and activity in female CFs may contribute to this sex disparity. The results show that paracrine CNP signaling in CFs has antifibrotic and antihypertrophic effects. The CNP/GC-B/cGMP pathway might be a target for therapies combating pathological cardiac remodeling.

Authors

Franziska Werner, Estefania Prentki Santos, Konstanze Michel, Hanna Schrader, Katharina Völker, Tamara Potapenko, Lisa Krebes, Marco Abesser, Dorothe Möllmann, Martin Schlattjan, Hannes Schmidt, Boris V. Skryabin, Katarina Špiranec Spes, Kai Schuh, Christopher P. Denton, Hideo A. Baba, Michaela Kuhn

Orai1 calcium channel inhibition prevents progression of chronic pancreatitis

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Abstract

Patients with recurrent acute pancreatitis (RAP) are at significant risk of developing early chronic pancreatitis (CP), which progresses into irreversible, end-stage CP with severe symptoms. There is no specific therapy in RAP or in early CP that may hinder disease progression. The pathogenesis of CP is complex and involves interactions among multiple cell types, including pancreatic acinar, ductal, and stellate cells (PSC). Therefore, it is pivotal to identify common pathogenic pathways in these cells that could be targeted pharmacologically. The Orai1-mediated store-operated Ca2+ entry (SOCE) is a ubiquitous signaling mechanism, which may become overactivated in pathological states resulting intracellular Ca2+ overload. In this study, we used ex vivo and in vivo preclinical disease models to demonstrate that Orai1 inhibition prevents progression of RAP and early CP. The selective Orai1 inhibitor CM5480 restored the expression of SOCE-associated regulatory factor in acinar cells, prevented uncontrolled Ca2+ elevation, protected acinar and ductal functions, mitigated immune cell infiltration, and diminished PSC activation, proliferation and migration. We suggest that the overactivation of Orai1 is a crucial pathogenetic event in the progression of early CP, and inhibition of Orai1 could prevent the development of end-stage CP.

Authors

Viktória Szabó, Noémi Csákány-Papp, Marietta Görög, Tamara Madacsy, Árpád Varga, Aletta Kiss, Balint Tel, Boldizsár Jójárt, Tim Crul, Krisztina Dudás, Mária Bagyánszki, Nikolett Bódi, Ferhan Ayaydin, Shyam Jee, Laszlo Tiszlavicz, Kenneth A. Stauderman, Sudarshan Hebbar, Petra Pallagi, József Maléth

Eculizumab treatment alters the proteometabolome beyond the inhibiton of complement

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Abstract

Therapeutic strategies targeting complement have revolutionized the treatment of myasthenia gravis (MG). However, a deeper understanding of complement modulation in the human system is required to improve treatment responses and identify “off-target effects” shaping long-term outcomes. For this purpose, we studied a cohort of MG patients treated with either eculizumab (n = 10) or azathioprine (n = 10) as well as treatment-naïve (n = 10) patients using a combined proteomics and metabolomics approach. This strategy confirmed known effects of eculizumab on the terminal complement cascade. Beyond that, eculizumab modulated the serum proteometabolome as distinct pathways were altered in eculizumab-treated patients including the oxidative stress response, mitogen-activated protein kinase signaling and lipid metabolism with particular emphasis on arachidonic acid signaling. We detected reduced levels of arachidonate 5-lipoxygenase (ALOX5) and leukotriene A4 (LTA4) in eculizumab-treated patients. Mechanistically, ligation of the C5a receptor (C5aR) is needed for ALOX5 metabolism and generation of downstream leukotrienes. As eculizumab prevents cleavage of C5 into C5a, decreased engagement of C5aR may inhibit ALOX5-mediated synthesis of pro-inflammatory leukotrienes. These findings indicate distinct “off-target effects” induced by eculizumab, illuminating potential mechanisms of action that may be harnessed to improve treatment outcomes.

Authors

Christopher Nelke, Christina B. Schroeter, Frauke Stascheit, Niklas Huntemann, Marc Pawlitzki, Alice G. Willison, Saskia Räuber, Nico Melzer, Ute Distler, Stefan Tenzer, Kai Stühler, Andreas Roos, Andreas Meisel, Sven G. Meuth, Tobias Ruck

The TLR7-IRF-5 axis sensitizes memory CD4⁺ T cells to Fas-mediated apoptosis during HIV-1 infection

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Abstract

HIV-1 infection is characterized by a strong inflammatory environment, tissue disruption, and a progressive decline in CD4+ T cell count. Despite treatment with antiretroviral therapy (ART), the majority of persons living with HIV (PLWH) maintain residual levels of inflammation, low degree of immune activation, and higher sensitivity to cell death in their memory CD4+ T-cell compartment. To date, the mechanisms responsible for this high sensitivity remain elusive. We have identified the transcription factor IRF-5 to be involved in impairing the maintenance of murine CD4+ T cells in a chronic inflammatory environment. Here, we investigate whether IRF-5 also contributes to memory CD4+ T cell loss during HIV-1 infection. We show that TLR7 and IRF-5 were upregulated in memory CD4+ T cells from PLWH, when compared with naturally protected elite controllers and HIVfree participants. TLR7 was upstream of IRF-5, promoting Caspase 8 expression in CD4+ T cells from ART HIV-1+ but not from HIVfree participants. Moreover, IRF-5 and TLR7 expression inversely correlated with CD4+ T cell counts in primary HIV infection. Interestingly, the TLR7-IRF-5 axis acted synergistically with the Fas/FasL pathway, suggesting that TLR7 and IRF-5 expression in ART HIV-1+ memory CD4+ T cells represents an imprint that predisposes cells to Fas-mediated apoptosis. This predisposition could be blocked using IRF-5 inhibitory peptides. Thus, we propose IRF-5 blockade as a possible therapy to prevent memory CD4+ T cell loss in PLWH.

Authors

Liseth Carmona-Perez, Xavier Dagenais-Lussier, Linh Thuy Mai, Tanja Stögerer, Sharada Swaminathan, Stephane Isnard, Matthew R. Rice, Betsy J. Barnes, Jean Pierre Routy, Julien van Grevenynghe, Simona Stager

Disruption of the nuclear localization signal in RBM20 is causative in dilated cardiomyopathy

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Abstract

Human patients carrying genetic mutations in RNA binding motif 20 (RBM20) develop a clinically aggressive dilated cardiomyopathy (DCM). Genetic mutation knock-in (KI) animal models imply that altered function of the arginine-serine-rich (RS) domain is crucial for severe DCM. To test this hypothesis, we generated an RS domain deletion mouse model (Rbm20ΔRS). We show that Rbm20ΔRS mice manifest DCM with mis-splicing of RBM20 target transcripts. We found that RBM20 is mis-localized to the sarcoplasm in Rbm20ΔRS mice, which led to the formation of RBM20 granules similar to those detected in mutation KI animals. In contrast, mice lacking the RNA recognition motif (RRM) show similar mis-splicing of RBM20 target genes, but do not develop DCM or exhibit RBM20 granule formation. Using in vitro studies with immunocytochemical staining, we demonstrate that only DCM-associated mutations in the RS domain facilitate RBM20 nucleocytoplasmic transport and promote granule assembly. Further, we defined the core nuclear localization signal (NLS) within the RS domain. Mutation analysis of phosphorylation sites in the RS domain indicate that this modification is dispensable for RBM20 nucleocytoplasmic transport. Collectively, our findings revealed that disruption of RS domain-mediated nuclear localization is crucial for severe DCM caused by NLS mutations.

Authors

Yanghai Zhang, Zachery R. Gregorich, Yujuan Wang, Camila U. Braz, Jibin Zhang, Yang Liu, Peiheng Liu, Jiaxi Shen, Nanyumuzi Aori, Timothy A. Hacker, Henk Granzier, Wei Guo

Specific regulation of mechanical nociception by Gβ5 involves GABA-B receptors

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Abstract

Mechanical, thermal, and chemical pain sensation is conveyed by primary nociceptors, a subset of sensory afferent neurons. The intracellular regulation of the primary nociceptive signal is an area of active study. We report here the discovery of a Gβ5-dependent regulatory pathway within mechanical nociceptors that restrains anti-nociceptive input from metabotropic GABA-B receptors. In mice with conditional knockout (cKO) of Gnb5 targeted to peripheral sensory neurons, we demonstrate the impairment of mechanical, thermal, and chemical nociception. We further report the specific loss of mechanical nociception in Rgs7-Cre+/-; Gnb5fl/fl mice but not in Rgs9-Cre+/-; Gnb5fl/fl mice, suggesting that Gβ5 might specifically regulate mechanical pain in Rgs7+ cells. Additionally, Gβ5-dependent and Rgs7-associated mechanical nociception is dependent upon GABA-B receptor signaling since both were abolished by treatment with a GABA-B receptor antagonist and since cKO of Gβ5 from sensory cells or from Rgs7+ cells potentiated the analgesic effects of GABA-B agonists. Following activation by the Mrgprd agonist β-alanine, enhanced sensitivity to inhibition by baclofen was observed in primary cultures of Rgs7+ sensory neurons harvested from Rgs7-Cre+/-; Gnb5fl/fl mice. Taken together, these results suggest that the targeted inhibition of Gβ5 function in Rgs7+ sensory neurons might provide specific relief for mechanical allodynia, including that contributing to chronic neuropathic pain, without reliance on exogenous opioids.

Authors

Mritunjay Pandey, Jian-Hua Zhang, Poorni R. Adikaram, Claire M. Kittock, Nicole Lue, Adam M. Awe, Katherine N. Degner, Nirmal Jacob, Jenna N. Staples, Rachel Thomas, Allison B. Kohnen, Sundar Ganesan, Juraj Kabat, Ching-Kang Chen, William F. Simonds

TIAM1 acts as an actin organization regulator to control adipose-derived pericyte cell fate

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Abstract

Pericytes are multipotent mesenchymal precursor cells that demonstrate tissue-specific properties. In this study, by comparing human adipose and periosteal-derived pericyte microarrays, we identified TIAM1 as a key regulator of cell morphology and differentiation decisions. TIAM1 represents a tissue-specific determinant between predispositions for adipocytic versus osteoblastic differentiation in human pericytes. TIAM1 overexpression promotes an adipogenic phenotype, whereas its downregulation amplifies osteogenic differentiation. These results were replicated in vivo xenograft animal model, in which TIAM1 misexpression altered bone or adipose tissue generation in an intramuscular xenograft animal model. Changes in pericyte differentiation potential induced by TIAM1 misexpression correlated with actin organization and altered cytoskeletal morphology. Small molecule inhibitors of either Rac1 or RhoA/ROCK signaling reversed TIAM1-induced morphology and differentiation in pericytes. Finally, pericytes within calcified vessels demonstrated decreased TIAM1 expression in the diseased area compared to the healthy tissue. In summary, our results demonstrate that TIAM1 regulates the cellular morphology and differentiation potential of human pericytes, representing a molecular switch between osteogenic and adipogenic cell fates.

Authors

Ginny Ching-Yun Hsu, Yiyun Wang, Amy Z. Lu, Mario A. Gomez-Salazar, Jiajia Xu, Dongqing Li, Carolyn Meyers, Stefano Negri, Sintawat Wangsiricharoen, Kristen P. Broderick, Bruno Peault, Carol D. Morris, Aaron W. James

High-fat diet plus HNF1A variant promotes polyps by activating β-catenin in early onset colorectal cancer

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Abstract

The incidence of early onset colorectal cancer (EO-CRC) is rising and is poorly understood. Lifestyle factors and altered genetic background possibly contribute. Here we performed targeted exon sequencing of archived leukocyte DNA from 158 EO-CRC participants, which identified a missense mutation at p.A98V within the proximal DNA binding domain of Hepatic Nuclear Factor 1 alpha (HNF1AA98V, Rs1800574). The HNF1AA98V exhibited reduced DNA binding. To test function, the HNF1A variant was introduced into the mouse genome by CRISPR/Cas9 and the mice were placed on either a high fat (HFD) or high sugar diet (HSD). Only 1% of the HNF1A mutant mice developed polyps on normal chow; however,19% and 3% developed polyps on the HFD and HSD, respectively. RNA-Seq revealed an increase in metabolic, immune, lipid biogenesis genes and Wnt/β-catenin signaling components in the HNF1A mutant relative to the wildtype mice. Mouse polyps and colon cancers from subjects carrying the HNF1AA98V variant exhibited reduced CDX2 and elevated β-catenin proteins. We further demonstrated decreased occupancy of HNF1AA98V at the Cdx2 locus and reduced Cdx2 promoter activity compared to wildtype HNF1A. Collectively, our study shows that the HNF1AA98V variant plus HFD promotes the formation of colonic polyps by activating β-catenin via decreasing Cdx2 expression.

Authors

Heyu Song, Ricky A. Sontz, Matthew J. Vance, Julia M. Morris, Sulaiman Sheriff, Songli Zhu, Suzann Duan, Jiping Zeng, Erika Koeppe, Ritu Pandey, Curtis A. Thorne, Elena M. Stoffel, Juanita L. Merchant

Gastric vagal afferent signaling to the basolateral amygdala mediates anxiety-like behaviors in experimental colitis mice

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Abstract

Inflammatory bowel disease (IBD) is a relapsing-remitting disorder characterized by chronic inflammation of the gastrointestinal (GI) tract. Anxiety symptoms are commonly observed in IBD patients, but the mechanistic link between IBD and anxiety remains elusive. Here, we sought to characterize gut-to-brain signaling and brain circuitry responsible for the pathological expression of anxiety-like behaviors in male dextran sulfate sodium (DSS)-induced experimental colitis mice. We found that DSS-treated mice displayed increased anxiety-like behaviors, which were prevented by bilateral GI vagal afferent ablation. The locus coeruleus (LC) is a relay center connecting the nucleus tractus solitarius to the basolateral amygdala (BLA) in controlling anxiety-like behaviors. Chemogenetic silencing of noradrenergic LC projections to the BLA reduced anxiety-like behaviors in DSS-treated mice. This work expands our understanding of the neural mechanisms by which IBD leads to comorbid anxiety and emphasizes a critical role of gastric vagal afferent signaling in gut-to-brain regulation of emotional states.

Authors

Chin-Hao Chen, Tsung-Chih Tsai, Yi-Jen Wu, Kuei-Sen Hsu