The mechanisms of pain induction by inflammation have been extensively studied. However, the mechanisms of pain resolution are not fully understood. Here, we report that GPR37, expressed by macrophages (MΦs) but not microglia, contributes to the resolution of inflammatory pain. Neuroprotectin D1 (NPD1) and prosaptide TX14 increase intracellular Ca2+ (iCa2+) levels in GPR37-transfected HEK293 cells. NPD1 and TX14 also bind to GPR37 and cause GPR37-dependent iCa2+ increases in peritoneal MΦs. Activation of GPR37 by NPD1 and TX14 triggers MΦ phagocytosis of zymosan particles via calcium signaling. Hind paw injection of pH-sensitive zymosan particles not only induces inflammatory pain and infiltration of neutrophils and MΦs, but also causes GPR37 upregulation in MΦs, phagocytosis of zymosan particles and neutrophils by MΦs in inflamed paws, and resolution of inflammatory pain in WT mice. Mice lacking Gpr37 display deficits in MΦ phagocytic activity and delayed resolution of inflammatory pain. Gpr37-deficient MΦs also show dysregulations of proinflammatory and antiinflammatory cytokines. MΦ depletion delays the resolution of inflammatory pain. Adoptive transfer of WT but not Gpr37-deficient MΦs promotes the resolution of inflammatory pain. Our findings reveal a previously unrecognized role of GPR37 in regulating MΦ phagocytosis and inflammatory pain resolution.
Sangsu Bang, Ya-Kai Xie, Zhi-Jun Zhang, Zilong Wang, Zhen-Zhong Xu, Ru-Rong Ji
Mutations in superoxide dismutase 1 (SOD1) are responsible for 20% of familial ALS. Given the gain of toxic function in this dominantly inherited disease, lowering SOD1 mRNA and protein is predicted to provide therapeutic benefit. An early generation antisense oligonucleotide (ASO) targeting SOD1 was identified and tested in a phase I human clinical trial, based on modest protection in animal models of SOD1 ALS. Although the clinical trial provided encouraging safety data, the drug was not advanced because there was progress in designing other, more potent ASOs for CNS application. We have developed next-generation SOD1 ASOs that more potently reduce SOD1 mRNA and protein and extend survival by more than 50 days in SOD1G93A rats and by almost 40 days in SOD1G93A mice. We demonstrated that the initial loss of compound muscle action potential in SOD1G93A mice is reversed after a single dose of SOD1 ASO. Furthermore, increases in serum phospho-neurofilament heavy chain levels, a promising biomarker for ALS, are stopped by SOD1 ASO therapy. These results define a highly potent, new SOD1 ASO ready for human clinical trial and suggest that at least some components of muscle response can be reversed by therapy.
Alex McCampbell, Tracy Cole, Amy J. Wegener, Giulio S. Tomassy, Amy Setnicka, Brandon J. Farley, Kathleen M. Schoch, Mariah L. Hoye, Mark Shabsovich, Linhong Sun, Yi Luo, Mingdi Zhang, Sai Thankamony, David W. Salzman, Merit Cudkowicz, Danielle L. Graham, C. Frank Bennett, Holly B. Kordasiewicz, Eric E. Swayze, Timothy M. Miller
Purinergic receptor-7 (P2X7R) signaling controls Th17 and Th1 generation/differentiation, while NOD-like receptor P3 (NLRP3) acts as a Th2 transcriptional factor. Here, we demonstrated the existence of a P2X7R/NLRP3 pathway in T cells that is dysregulated by a P2X7R intracellular region loss-of-function mutation, leading to NLRP3 displacement and to excessive Th17 generation due to abrogation of the NLRP3-mediated Th2 program. This ultimately resulted in poor outcomes in cardiac-transplanted patients carrying the mutant allele, who showed abnormal Th17 generation. Transient NLRP3 silencing in nonmutant T cells or overexpression in mutant T cells normalized the Th profile. Interestingly, IL-17 blockade reduced Th17 skewing of human T cells in vitro and abrogated the severe allograft vasculopathy and abnormal Th17 generation observed in preclinical models in which P2X7R was genetically deleted. This P2X7R intracellular region mutation thus impaired the modulatory effects of P2X7R on NLRP3 expression and function in T cells and led to NLRP3 dysregulation and Th17 skewing, delineating a high-risk group of cardiac-transplanted patients who may benefit from personalized therapy.
Francesca D’Addio, Andrea Vergani, Luciano Potena, Anna Maestroni, Vera Usuelli, Moufida Ben Nasr, Roberto Bassi, Sara Tezza, Sergio Dellepiane, Basset El Essawy, Maria Iascone, Attilio Iacovoni, Laura Borgese, Kaifeng Liu, Gary Visner, Sirano Dhe-Paganon, Domenico Corradi, Reza Abdi, Randall C. Starling, Franco Folli, Gian Vincenzo Zuccotti, Mohamed H. Sayegh, Peter S. Heeger, Anil Chandraker, Francesco Grigioni, Paolo Fiorina
Chromatin remodeler Brahma related gene 1 (BRG1) is silenced in approximately 10% of human pancreatic ductal adenocarcinomas (PDAs). We previously showed that BRG1 inhibits the formation of intraductal pancreatic mucinous neoplasm (IPMN) and that IPMN-derived PDA originated from ductal cells. However, the role of BRG1 in pancreatic intraepithelial neoplasia–derived (PanIN-derived) PDA that originated from acinar cells remains elusive. Here, we found that exclusive elimination of Brg1 in acinar cells of Ptf1a-CreER; KrasG12D; Brg1fl/fl mice impaired the formation of acinar-to-ductal metaplasia (ADM) and PanIN independently of p53 mutation, while PDA formation was inhibited in the presence of p53 mutation. BRG1 bound to regions of the Sox9 promoter to regulate its expression and was critical for recruitment of upstream regulators, including PDX1, to the Sox9 promoter and enhancer in acinar cells. SOX9 expression was downregulated in BRG1-depleted ADMs/PanINs. Notably, Sox9 overexpression canceled this PanIN-attenuated phenotype in KBC mice. Furthermore, Brg1 deletion in established PanIN by using a dual recombinase system resulted in regression of the lesions in mice. Finally, BRG1 expression correlated with SOX9 expression in human PDAs. In summary, BRG1 is critical for PanIN initiation and progression through positive regulation of SOX9. Thus, the BRG1/SOX9 axis is a potential target for PanIN-derived PDA.
Motoyuki Tsuda, Akihisa Fukuda, Nilotpal Roy, Yukiko Hiramatsu, Laura Leonhardt, Nobuyuki Kakiuchi, Kaja Hoyer, Satoshi Ogawa, Norihiro Goto, Kozo Ikuta, Yoshito Kimura, Yoshihide Matsumoto, Yutaka Takada, Takuto Yoshioka, Takahisa Maruno, Yuichi Yamaga, Grace E. Kim, Haruhiko Akiyama, Seishi Ogawa, Christopher V. Wright, Dieter Saur, Kyoichi Takaori, Shinji Uemoto, Matthias Hebrok, Tsutomu Chiba, Hiroshi Seno
The biological activity of 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3] remains controversial, but it has been suggested that it contributes to fracture healing. Cyp24a1–/– mice, synthesizing no 24R,25(OH)2D3, show suboptimal endochondral ossification during fracture repair, with smaller callus and reduced stiffness. These defects were corrected by 24R,25(OH)2D3 treatment, but not by 1,25-dihydroxyvitamin D3. Microarrays with Cyp24a1–/– callus mRNA identified FAM57B2 as a mediator of the 24R,25(OH)2D3 effect. FAM57B2 produced lactosylceramide (LacCer) upon specific binding of 24R,25(OH)2D3. Fam57b inactivation in chondrocytes (Col2-Cre Fam57bfl/fl) phenocopied the callus formation defect of Cyp24a1–/– mice. LacCer or 24R,25(OH)2D3 injections restored callus volume, stiffness, and mineralized cartilage area in Cyp24a1-null mice, but only LacCer rescued Col2-Cre Fam57bfl/fl mice. Gene expression in callus tissue suggested that the 24R,25(OH)2D3/FAM57B2 cascade affects cartilage maturation. We describe a previously unrecognized pathway influencing endochondral ossification during bone repair through LacCer production upon binding of 24R,25(OH)2D3 to FAM57B2. Our results identify potential new approaches to ameliorate fracture healing.
Corine Martineau, Roy Pascal Naja, Abdallah Husseini, Bachar Hamade, Martin Kaufmann, Omar Akhouayri, Alice Arabian, Glenville Jones, René St-Arnaud
Podocyte malfunction occurs in autoimmune and nonautoimmune kidney disease. Calcium signaling is essential for podocyte injury, but the role of Ca2+/calmodulin–dependent kinase (CaMK) signaling in podocytes has not been fully explored. We report that podocytes from patients with lupus nephritis and focal segmental glomerulosclerosis and lupus-prone and lipopolysaccharide- or adriamycin-treated mice display increased expression of CaMK IV (CaMK4), but not CaMK2. Mechanistically, CaMK4 modulated podocyte motility by altering the expression of the GTPases Rac1 and RhoA and suppressed the expression of nephrin, synaptopodin, and actin fibers in podocytes. In addition, it phosphorylated the scaffold protein 14-3-3β, which resulted in the release and degradation of synaptopodin. Targeted delivery of a CaMK4 inhibitor to podocytes preserved their ultrastructure, averted immune complex deposition and crescent formation, and suppressed proteinuria in lupus-prone mice and proteinuria in mice exposed to lipopolysaccharide-induced podocyte injury by preserving nephrin/synaptopodin expression. In animals exposed to adriamycin, podocyte-specific delivery of a CaMK4 inhibitor prevented and reversed podocyte injury and renal disease. We conclude that CaMK4 is pivotal in immune and nonimmune podocyte injury and that its targeted cell-specific inhibition preserves podocyte structure and function and should have therapeutic value in lupus nephritis and podocytopathies, including focal segmental glomerulosclerosis.
Kayaho Maeda, Kotaro Otomo, Nobuya Yoshida, Mones S. Abu-Asab, Kunihiro Ichinose, Tomoya Nishino, Michihito Kono, Andrew Ferretti, Rhea Bhargava, Shoichi Maruyama, Sean Bickerton, Tarek M. Fahmy, Maria G. Tsokos, George C. Tsokos
Myocardial infarction (MI) arising from obstruction of the coronary circulation engenders massive cardiomyocyte loss and replacement by non-contractile scar tissue, leading to pathological remodeling, dysfunction, and ultimately heart failure. This is presently a global health problem for which there is no effective cure. Following MI, the innate immune system directs the phagocytosis of dead cell debris in an effort to stimulate cell repopulation and tissue renewal. In the mammalian adult heart, however, the persistent influx of immune cells, coupled with the lack of an inherent regenerative capacity, results in cardiac fibrosis. Here, we reveal that stimulation of cardiac lymphangiogenesis with VEGF-C improves clearance of the acute inflammatory response after MI by trafficking immune cells to draining mediastinal lymph nodes (MLNs) in a process dependent on lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1). Deletion of Lyve1 in mice, preventing docking and transit of leukocytes through the lymphatic endothelium, results in exacerbation of chronic inflammation and long-term deterioration of cardiac function. Our findings support targeting of the lymphatic/immune cell axis as a therapeutic paradigm to promote immune modulation and heart repair.
Joaquim Miguel Vieira, Sophie Norman, Cristina Villa del Campo, Thomas J. Cahill, Damien N. Barnette, Mala Gunadasa-Rohling, Louise A. Johnson, David R. Greaves, Carolyn A. Carr, David G. Jackson, Paul R. Riley
T cells play a key role in immune-mediated glomerulonephritis, but how cytotoxic T cells interact with podocytes remains unclear. To address this, we injected EGFP-specific CD8+ T cells from just EGFP death inducing (Jedi) mice into transgenic mice with podocyte-specific expression of EGFP. In healthy mice, Jedi T cells could not access EGFP+ podocytes. Conversely, when we induced nephrotoxic serum nephritis (NTSN) and injected Jedi T cells, EGFP+ podocyte transgenic mice showed enhanced proteinuria and higher blood urea levels. Morphometric analysis showed greater loss of EGFP+ podocytes, which was associated with severe crescentic and necrotizing glomerulonephritis. Notably, only glomeruli with disrupted Bowman’s capsule displayed massive CD8+ T cell infiltrates that were in direct contact with EGFP+ podocytes, causing their apoptosis. Thus, under control conditions with intact Bowman’s capsule, podocytes are not accessible to CD8+ T cells. However, breaches in Bowman’s capsule, as also noted in human crescentic glomerulonephritis, allow access of CD8+ T cells to the glomerular tuft and podocytes, resulting in their destruction. Through these mechanisms, a potentially reversible glomerulonephritis undergoes an augmentation process to a rapidly progressive glomerulonephritis, leading to end-stage kidney disease. Translating these mechanistic insights to human crescentic nephritis should direct future therapeutic interventions at blocking CD8+ T cells, especially in progressive stages of rapidly progressive glomerulonephritis.
Anqun Chen, Kyung Lee, Vivette D. D’Agati, Chengguo Wei, Jia Fu, Tian-Jun Guan, John Cijiang He, Detlef Schlondorff, Judith Agudo
Clarin-1, a tetraspan-like membrane protein defective in Usher syndrome type IIIA (USH3A), is essential for hair bundle morphogenesis in auditory hair cells. We report a new synaptic role for clarin-1 in mouse auditory hair cells elucidated by characterization of Clrn1 total (Clrn1ex4–/–) and postnatal hair cell–specific conditional (Clrn1ex4fl/fl Myo15-Cre+/–) knockout mice. Clrn1ex4–/– mice were profoundly deaf, whereas Clrn1ex4fl/fl Myo15-Cre+/– mice displayed progressive increases in hearing thresholds, with, initially, normal otoacoustic emissions and hair bundle morphology. Inner hair cell (IHC) patch-clamp recordings for the 2 mutant mice revealed defective exocytosis and a disorganization of synaptic F-actin and CaV1.3 Ca2+ channels, indicative of a synaptopathy. Postsynaptic defects were also observed, with an abnormally broad distribution of AMPA receptors associated with a loss of afferent dendrites and defective electrically evoked auditory brainstem responses. Protein-protein interaction assays revealed interactions between clarin-1 and the synaptic CaV1.3 Ca2+ channel complex via the Cavβ2 auxiliary subunit and the PDZ domain–containing protein harmonin (defective in Usher syndrome type IC). Cochlear gene therapy in vivo, through adeno-associated virus–mediated Clrn1 transfer into hair cells, prevented the synaptic defects and durably improved hearing in Clrn1ex4fl/fl Myo15-Cre+/– mice. Our results identify clarin-1 as a key organizer of IHC ribbon synapses, and suggest new treatment possibilities for USH3A patients.
Didier Dulon, Samantha Papal, Pranav Patni, Matteo Cortese, Philippe F.Y. Vincent, Margot Tertrais, Alice Emptoz, Aziz Tlili, Yohan Bouleau, Vincent Michel, Sedigheh Delmaghani, Alain Aghaie, Elise Pepermans, Olinda Allegria-Prevot, Omar Akil, Lawrence Lustig, Paul Avan, Saaid Safieddine, Christine Petit, Aziz El-Amraoui
High-risk neuroblastoma is a devastating malignancy with very limited therapeutic options. Here, we identify withaferin A (WA) as a natural ferroptosis-inducing agent in neuroblastoma, which acts through a novel double-edged mechanism. WA dose-dependently either activates the nuclear factor–like 2 pathway through targeting of Kelch-like ECH-associated protein 1 (noncanonical ferroptosis induction) or inactivates glutathione peroxidase 4 (canonical ferroptosis induction). Noncanonical ferroptosis induction is characterized by an increase in intracellular labile Fe(II) upon excessive activation of heme oxygenase-1, which is sufficient to induce ferroptosis. This double-edged mechanism might explain the superior efficacy of WA as compared with etoposide or cisplatin in killing a heterogeneous panel of high-risk neuroblastoma cells, and in suppressing the growth and relapse rate of neuroblastoma xenografts. Nano-targeting of WA allows systemic application and suppressed tumor growth due to an enhanced accumulation at the tumor site. Collectively, our data propose a novel therapeutic strategy to efficiently kill cancer cells by ferroptosis.
Behrouz Hassannia, Bartosz Wiernicki, Irina Ingold, Feng Qu, Simon Van Herck, Yulia Y. Tyurina, Hülya Bayır, Behnaz A. Abhari, Jose Pedro Friedmann Angeli, Sze Men Choi, Eline Meul, Karen Heyninck, Ken Declerck, Chandra Sekhar Chirumamilla, Maija Lahtela-Kakkonen, Guy Van Camp, Dmitri V. Krysko, Paul G. Ekert, Simone Fulda, Bruno G. De Geest, Marcus Conrad, Valerian E. Kagan, Wim Vanden Berghe, Peter Vandenabeele, Tom Vanden Berghe