Diabetes elevates the risk for neurological diseases, but little is known about the underlying mechanisms. Brain-derived neurotrophic factor (BDNF) is secreted by microvascular endothelial cells (ECs) in the brain, functioning as a neuroprotectant through the activation of the neurotrophic tyrosine kinase receptor TRKB. In a rat model of streptozotocin-induced hyperglycemia, we found that endothelial activation of MMP9 altered TRKB-dependent trophic pathways by degrading TRKB in neurons. Treatment of brain microvascular ECs with advanced glycation endproducts (AGE), a metabolite commonly elevated in diabetic patients, increased MMP9 activation, similar to in vivo findings. Recombinant human MMP9 degraded the TRKB ectodomain in primary neuronal cultures, suggesting that TRKB could be a substrate for MMP9 proteolysis. Consequently, AGE-conditioned endothelial media with elevated MMP9 activity degraded the TRKB ectodomain and simultaneously disrupted the ability of endothelium to protect neurons against hypoxic injury. Our findings demonstrate that neuronal TRKB trophic function is ablated by MMP9-mediated degradation in the diabetic brain, disrupting cerebrovascular trophic coupling and leaving the brain vulnerable to injury.
Deepti Navaratna, Xiang Fan, Wendy Leung, Josephine Lok, Shuzhen Guo, Changhong Xing, Xiaoying Wang, Eng H. Lo
Brown adipose tissue (BAT) burns fat to produce heat when the body is exposed to cold and plays a role in energy metabolism. Using fluorodeoxyglucose-positron emission tomography and computed tomography, we previously reported that BAT decreases with age and thereby accelerates age-related accumulation of body fat in humans. Thus, the recruitment of BAT may be effective for body fat reduction. In this study, we examined the effects of repeated stimulation by cold and capsinoids (nonpungent capsaicin analogs) in healthy human subjects with low BAT activity. Acute cold exposure at 19°C for 2 hours increased energy expenditure (EE). Cold-induced increments of EE (CIT) strongly correlated with BAT activity independently of age and fat-free mass. Daily 2-hour cold exposure at 17°C for 6 weeks resulted in a parallel increase in BAT activity and CIT and a concomitant decrease in body fat mass. Changes in BAT activity and body fat mass were negatively correlated. Similarly, daily ingestion of capsinoids for 6 weeks increased CIT. These results demonstrate that human BAT can be recruited even in individuals with decreased BAT activity, thereby contributing to body fat reduction.
Takeshi Yoneshiro, Sayuri Aita, Mami Matsushita, Takashi Kayahara, Toshimitsu Kameya, Yuko Kawai, Toshihiko Iwanaga, Masayuki Saito
Numerous common genetic variants have been linked to blood pressure, but no underlying mechanism has been elucidated. Population studies have revealed that the variant rs5068 (A/G) in the 3′ untranslated region of
Pankaj Arora, Connie Wu, Abigail May Khan, Donald B. Bloch, Brandi N. Davis-Dusenbery, Anahita Ghorbani, Ester Spagnolli, Andrew Martinez, Allicia Ryan, Laurel T. Tainsh, Samuel Kim, Jian Rong, Tianxiao Huan, Jane E. Freedman, Daniel Levy, Karen K. Miller, Akiko Hata, Federica del Monte, Sara Vandenwijngaert, Melissa Swinnen, Stefan Janssens, Tara M. Holmes, Emmanuel S. Buys, Kenneth D. Bloch, Christopher Newton-Cheh, Thomas J. Wang
Amélie Bonnefond, Anne Raimondo, Fanny Stutzmann, Maya Ghoussaini, Shwetha Ramachandrappa, David C. Bersten, Emmanuelle Durand, Vincent Vatin, Beverley Balkau, Olivier Lantieri, Violeta Raverdy, François Pattou, Wim Van Hul, Luc Van Gaal, Daniel J. Peet, Jacques Weill, Jennifer L. Miller, Fritz Horber, Anthony P. Goldstone, Daniel J. Driscoll, John B. Bruning, David Meyre, Murray L. Whitelaw, Philippe Froguel
Adenoid cystic carcinoma (ACC) is a rare malignancy that can occur in multiple organ sites and is primarily found in the salivary gland. While the identification of recurrent fusions of the
Philip J. Stephens, Helen R. Davies, Yoshitsugu Mitani, Peter Van Loo, Adam Shlien, Patrick S. Tarpey, Elli Papaemmanuil, Angela Cheverton, Graham R. Bignell, Adam P. Butler, John Gamble, Stephen Gamble, Claire Hardy, Jonathan Hinton, Mingming Jia, Alagu Jayakumar, David Jones, Calli Latimer, Stuart McLaren, David J. McBride, Andrew Menzies, Laura Mudie, Mark Maddison, Keiran Raine, Serena Nik-Zainal, Sarah O’Meara, Jon W. Teague, Ignacio Varela, David C. Wedge, Ian Whitmore, Scott M. Lippman, Ultan McDermott, Michael R. Stratton, Peter J. Campbell, Adel K. El-Naggar, P. Andrew Futreal
Hippocampal development is coordinated by both extracellular factors like GABA neurotransmission and intracellular components like DISC1. We previously reported that SLC12A2-dependent GABA depolarization and DISC1 coregulate hippocampal neuronal development, and 2 SNPs in these genes linked to mRNA expression interactively increase schizophrenia risk. Using functional MRI, we now confirm this biological interaction in vivo by showing in 2 independent samples of healthy individuals (total
Joseph H. Callicott, Emer L. Feighery, Venkata S. Mattay, Michael G. White, Qiang Chen, David A.A. Baranger, Karen F. Berman, Bai Lu, Hongjun Song, Guo-li Ming, Daniel R. Weinberger
Multiple sclerosis (MS) is a genetically mediated autoimmune disease of the central nervous system. B cells have recently emerged as major contributors to disease pathogenesis, but the mechanisms responsible for the loss of B cell tolerance in patients with MS are largely unknown. In healthy individuals, developing autoreactive B cells are removed from the repertoire at 2 tolerance checkpoints during early B cell development. Both of these central and peripheral B cell tolerance checkpoints are defective in patients with rheumatoid arthritis (RA) and type 1 diabetes (T1D). Here, we found that only the peripheral, but not the central, B cell tolerance checkpoint is defective in patients with MS. We show that this specific defect is accompanied by increased activation and homeostatic proliferation of mature naive B cells. Interestingly, all of these MS features parallel defects observed in FOXP3-deficient IPEX patients, who harbor nonfunctional Tregs. We demonstrate that in contrast to patients with RA or T1D, bone marrow central B cell selection in MS appears normal in most patients. In contrast, patients with MS suffer from a specific peripheral B cell tolerance defect that is potentially attributable to impaired Treg function and that leads to the accumulation of autoreactive B cell clones in their blood.
Tuure Kinnunen, Nicolas Chamberlain, Henner Morbach, Tineke Cantaert, Megan Lynch, Paula Preston-Hurlburt, Kevan C. Herold, David A. Hafler, Kevin C. O’Connor, Eric Meffre
The ELR+-CXCL chemokines have been described typically as potent chemoattractants and activators of neutrophils during the acute phase of inflammation. Their role in atherosclerosis, a chronic inflammatory vascular disease, has been largely unexplored. Using a mouse model of atherosclerosis, we found that CXCL5 expression was upregulated during disease progression, both locally and systemically, but was not associated with neutrophil infiltration. Unexpectedly, inhibition of CXCL5 was not beneficial but rather induced a significant macrophage foam cell accumulation in murine atherosclerotic plaques. Additionally, we demonstrated that CXCL5 modulated macrophage activation, increased expression of the cholesterol efflux regulatory protein ABCA1, and enhanced cholesterol efflux activity in macrophages. These findings reveal a protective role for CXCL5, in the context of atherosclerosis, centered on the regulation of macrophage foam cell formation.
Anthony Rousselle, Fatimunnisa Qadri, Lisa Leukel, Rüstem Yilmaz, Jean-Fred Fontaine, Gabin Sihn, Michael Bader, Amrita Ahluwalia, Johan Duchene
Milk fat globule-EGF 8 (MFGE8) plays important, nonredundant roles in several biological processes, including apoptotic cell clearance, angiogenesis, and adaptive immunity. Several recent studies have reported a potential role for MFGE8 in regulation of the innate immune response; however, the precise mechanisms underlying this role are poorly understood. Here, we show that MFGE8 is an endogenous inhibitor of inflammasome-induced IL-1β production. MFGE8 inhibited necrotic cell–induced and ATP-dependent IL-1β production by macrophages through mediation of integrin β3 and P2X7 receptor interactions in primed cells.
Nicolas Deroide, Xuan Li, Dominique Lerouet, Emily Van Vré, Lauren Baker, James Harrison, Marine Poittevin, Leanne Masters, Lina Nih, Isabelle Margaill, Yoichiro Iwakura, Bernhard Ryffel, Marc Pocard, Alain Tedgui, Nathalie Kubis, Ziad Mallat
iRHOM2, encoded by the gene
Priya Darshinee A. Issuree, Thorsten Maretzky, David R. McIlwain, Sébastien Monette, Xiaoping Qing, Philipp A. Lang, Steven L. Swendeman, Kyung-Hyun Park-Min, Nikolaus Binder, George D. Kalliolias, Anna Yarilina, Keisuke Horiuchi, Lionel B. Ivashkiv, Tak W. Mak, Jane E. Salmon, Carl P. Blobel
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