Rationale. RNA binding protein 47 (RBM47) is required for embryonic endoderm development but a role in adult intestine is unknown. Objective. We studied intestine-specific Rbm47 knockout mice (Rbm47-IKO) following intestinal injury and made crosses into Apcmin/+ mice to examine alterations in intestinal proliferation, response to injury and tumorigenesis. We also interrogated human colorectal polyps and colon carcinoma tissue. Findings. Rbm47-IKO mice exhibit increased proliferation, abnormal villus morphology and cellularity, with corresponding changes in Rbm47-IKO organoids. Rbm47-IKO mice adapt to radiation injury and are protected against chemical-induced colitis, with Rbm47-IKO intestine showing upregulation of antioxidant and Wnt signaling pathways as well as stem cell and developmental genes. Furthermore, Rbm47-IKO mice are protected against colitis-associated cancer. By contrast, aged Rbm47-IKO mice develop spontaneous polyposis and Rbm47-IKO, Apcmin/+ mice manifest an increased intestinal polyp burden. RBM47 mRNA was decreased in human colorectal cancer versus paired normal tissue along with alternative splicing of TJP1 mRNA. Public databases revealed stage-specific reduction in RBM47 expression in colorectal cancer, associated independently with decreased overall survival. Conclusions. These findings implicate RBM47 as a cell-intrinsic modifier of intestinal growth, inflammatory and tumorigenic pathways.
Saeed Soleymanjahi, Valerie Blanc, Elizabeth A. Molitor, David M. Alvarado, Yan Xie, Vered Gazit, Jeffrey W. Brown, Kathleen Byrnes, Ta-Chiang Liu, Jason C. Mills, Matthew A. Ciorba, Deborah C. Rubin, Nicholas O. Davidson
Although the expression of Mex3 RNA binding family member B (MEX3B) is upregulated in human nasal epithelial cells (HENCs) predominately in the eosinophilic chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) subtype, its functions as an RNA binding protein in airway epithelial cells remain unknown. Here, we revealed the role of MEX3B based on different subtypes of CRS, and demonstrated that MEX3B decreased TGF-β receptor III (TGFBR3) mRNA level by binding to its 3’ UTR and reducing its stability in HNECs. TGF-βR3 was found to be a TGF-β2 specific coreceptor in HNECs. Knocking down or overexpressing MEX3B promoted or inhibited TGF-β2-induced phosphorylation of Smad2 in HNECs, respectively. TGF-βR3 and p-Smad2 levels were downregulated in CRSwNP compared with controls and CRS without nasal polyps (CRSsNP), with a more prominent downregulation in the eosinophilic CRSwNP. TGF-β2 promoted collagen production in HNECs. Collagen abundance decreased and edema scores increased in CRSwNP compared to control, again more prominently in the eosinophilic type. Collagen expression in eosinophilic CRSwNP was negatively correlated with MEX3B but positively correlated with TGF-βR3. These results suggest that MEX3B inhibits tissue fibrosis in eosinophilic CRSwNP by downregulating epithelial cell TGFBR3 expression; consequently, MEX3B might be a valuable therapeutic target against eosinophilic CRSwNP.
Jin-Xin Liu, Chen Ao-Nan, Qihong Yu, Ke-Tai Shi, Yi-Bo Liu, Cui-Lian Guo, Zhe-Zheng Wang, Yin Yao, Li Pan, Xiang Lu, Kai Xu, Heng Wang, Ming Zeng, Chaohong Liu, Robert P. Schleimer, Ning Wu, Bo Liao, Zheng Liu
BACKGROUND. Due to their immunoregulatory and tissue regenerative features, mesenchymal stromal cells (MSCs) are a promising novel tool for the management of ulcerative proctitis (UP). Here we report on a phase IIa clinical study to evaluate the impact of local MSC therapy in UP. METHODS. Thirteen refractory UP patients, with endoscopic Mayo score (EMS) 2 or 3, were included. Seven patients received 20-40 x 106 allogeneic MSCs (cohort 1), while six patients received 40-80 x 106 MSCs (cohort 2). Adverse events (AEs) were assessed at baseline and week 2, 6, 12, and 24. Clinical, endoscopic, and biochemical parameters were assessed at baseline, week 2 and 6. Furthermore, we evaluated the engraftment of MSCs, presence of donor-specific human leukocyte antigen (HLA) antibodies (DSAs), and we determined the impact of MSC therapy on the local immune compartment. RESULTS. No serious AEs were observed. The clinical Mayo score was significantly improved at week 2 and 6, and the EMS was significantly improved at week 6, compared to baseline. At week 6, donor MSCs were still detectable in rectum biopsies of 4/9 patients and DSAs against both HLA-class I and -class II were found. Mass cytometry showed a reduction of activated CD8+ T cells and CD16+ monocytes and an enrichment in mononuclear phagocytes and natural killer cells in biopsies after local MSC therapy. CONCLUSION. Local administration of allogeneic MSCs is safe, tolerable, and feasible for treatment of refractory UP and shows encouraging signs of clinical efficacy and modulation of local immune responses. This sets the stage for larger clinical trials. TRIAL REGISTRATION. clinicaltrialsregister.eu, EudraCT: 2017-003524-75, Dutch Trial register: NTR7205. FUNDING. ECCO grant 2020.
Laura F. Ouboter, Marieke C. Barnhoorn, Hein W. Verspaget, Leonie Plug, Emma S. Pool, Karoly Szuhai, Lukas J.A.C. Hawinkels, Melissa van Pel, Jaap Jan Zwaginga, Dave Roelen, Frits Koning, M. Fernanda Pascutti, Andrea van der Meulen - de Jong
Necrotizing enterocolitis (NEC) is a deadly gastrointestinal disease of premature infants that is associated with an exaggerated inflammatory response, dysbiosis of the gut microbiome, decreased epithelial cell proliferation, and gut barrier disruption. We describe an in vitro model of human neonatal small intestinal epithelium (Neonatal-Intestine-on-a-Chip) that mimics key features of intestinal physiology. This model utilizes premature infant intestinal enteroids grown from surgically harvested intestinal tissue and co-cultured with human intestinal microvascular endothelial cells within a microfluidic device. We used our Neonatal-Intestine-on-a-Chip to recapitulate NEC pathophysiology by adding infant-derived microbiota. This model, named NEC-on-a-Chip, recapitulates the predominant features of NEC including significant upregulation of pro-inflammatory cytokines, decreased intestinal epithelial cell markers, reduced epithelial proliferation, and disrupted epithelial barrier integrity. NEC-on-a-Chip provides an improved preclinical model of NEC that facilitates comprehensive analysis of the pathophysiology of NEC using precious clinical samples. This model is an advance towards a personalized medicine approach to test new therapeutics for this devastating disease.
Wyatt E. Lanik, Cliff J. Luke, Lila S. Nolan, Qingqing Gong, Lauren C. Frazer, Jamie M. Rimer, Sarah E. Gale, Raymond Luc, Shay S. Bidani, Carrie A. Sibbald, Angela N. Lewis, Belgacem Mihi, Pranjal Agrawal, Martin Goree, Marlie M. Maestas, Elise Hu, David G. Peters, Misty Good
Patients with neovascular AMD (nAMD) suffer vision loss from destructive angiogenesis, termed choroidal neovascularization (CNV). Macrophages are found in CNV lesions from nAMD patients. Additionally, Ccr2-/- mice, which lack classical monocyte-derived macrophages, show reduced CNV size. However, macrophages are highly diverse cells that can perform multiple functions. We performed single-cell RNA-sequencing on immune cells from wildtype and Ccr2-/- eyes to uncover macrophage heterogeneity during the laser-induced CNV mouse model of nAMD. We identified 12 macrophage clusters, including Spp1+ macrophages. Spp1+ macrophages were enriched from wildtype lasered eyes and expressed a pro-angiogenic transcriptome via multiple pathways, including vascular endothelial growth factor signaling, endothelial cell sprouting, cytokine signaling, and fibrosis. Additionally, Spp1+ macrophages expressed the marker CD11c, and CD11c+ macrophages were increased by laser and present in CNV lesions. Finally, CD11c+ macrophage depletion reduced CNV size by 40%. These findings broaden our understanding of ocular macrophage heterogeneity and implicate CD11c+ macrophages as a potential therapeutic target for treatment-resistant nAMD patients.
Steven Droho, Amrita Rajesh, Carla M. Cuda, Harris Perlman, Jeremy A. Lavine
Cholesterol-25-hydroxylase (CH25H), the biosynthetic enzyme for 25-hydroxycholesterol (25HC), is most highly expressed in the lung, but its role in lung biology is poorly defined. Recently, we reported that Ch25h is induced in monocyte-derived macrophages recruited to the airspace during resolution of lung inflammation and that 25HC promotes Liver X Receptor (LXR)-dependent clearance of apoptotic neutrophils by these cells. Ch25h and 25HC are, however, also robustly induced by lung-resident cells during the early hours of lung inflammation, suggesting additional cellular sources and targets. Here, using Ch25h-/- mice and exogenous 25HC in lung injury models, we provide evidence that 25HC sustains pro-inflammatory cytokines in the airspace and augments lung injury, at least in part, by inducing LXR-independent endoplasmic reticulum stress and endothelial leak. Suggesting an autocrine effect in endothelium, inhaled LPS upregulates pulmonary endothelial Ch25h and non-hematopoietic Ch25h deletion is sufficient to confer lung protection. In acute respiratory distress syndrome patients, airspace 25HC and alveolar macrophage CH25H were associated with markers of microvascular leak, endothelial activation, endoplasmic reticulum stress, inflammation, and clinical severity. Taken together, our findings suggest that 25HC deriving from and acting upon different cell types in the lung communicates distinct, temporal LXR-independent and -dependent signals to regulate inflammatory homeostasis.
Jennifer H. Madenspacher, Eric D. Morrell, Jeffrey G. McDonald, Bonne M. Thompson, Yue Li, Konstantin G. Birukov, Anna A. Birukova, Renee D. Stapleton, Aidin Alejo, Peer W. Karmaus, Julie M. Meacham, Prashant Rai, Carmen Mikacenic, Mark M. Wurfel, Michael B. Fessler
The inability of mature retinal ganglion cells (RGCs) to regenerate axons after optic nerve injury can be partially reversed by manipulating cell-autonomous and/or -non-autonomous factors. Although manipulations of cell-non-autonomous factors could have higher translational potential than genetic manipulations of RGCs, they have generally produced lower levels of optic nerve regeneration. Here we report that preconditioning resulting from mild lens injury (conditioning LI, cLI) prior to optic nerve damage induces far greater regeneration than LI after nerve injury or the pro-inflammatory agent zymosan given either before or after nerve damage. Unlike zymosan-induced regeneration, cLI is unaltered by depleting mature neutrophils or T cells or blocking receptors for known inflammation-derived growth factors (Oncomodulin, SDF1, CCL5), and is only partly diminished by suppressing CCR2+ monocyte recruitment. Repeated episodes of LI lead to full-length optic nerve regeneration, and pharmacological removal of local resident macrophages with the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 enables some axons to re-innervate the brain in just 6 weeks, comparable to the results obtained with the most effective genetic manipulations of RGCs. Thus, cell-non-autonomous interventions can induce high levels of optic nerve regeneration, paving the way to uncover potent, translatable therapeutic targets for CNS repair.
Qian Feng, Kimberly A. Wong, Larry I. Benowitz
Macrophages intimately interact with intestinal epithelial cells, but the consequences of defective macrophage–epithelial cell interactions for protection against enteric pathogens are poorly understood. Here, we show that in mice with a deletion in protein tyrosine phosphatase nonreceptor type 2 (PTPN2) in macrophages, infection with Citrobacter rodentium, a model of enteropathogenic and enterohemorrhagic E. coli infection in humans, promoted a strong type 1/IL-22–driven immune response, culminating in accelerated disease but also faster clearance of the pathogen. In contrast, deletion of PTPN2 specifically in epithelial cells rendered the epithelium unable to upregulate antimicrobial peptides and consequently resulted in a failure to eliminate the infection. The ability of PTPN2-deficient macrophages to induce faster recovery from C. rodentium was dependent on macrophage-intrinsic IL-22 production, which was highly increased in macrophages deficient in PTPN2. Our findings demonstrate the importance of macrophage-mediated factors, and especially macrophage-derived IL-22, for the induction of protective immune responses in the intestinal epithelium, and show that normal PTPN2 expression in the epithelium is crucial to allow for protection against enterohemorrhagic E. coli and other intestinal pathogens.
Marianne R. Spalinger, Vinicius Canale, Anica Becerra, Ali Shawki, Meli’sa Crawford, Alina N. Santos, Pritha Chatterjee, Jiang Li, Meera G. Nair, Declan F. McCole
As a hallmark for inflammatory bowel disease (IBD), elevated intestinal epithelial cell (IEC) death compromises the gut barrier, activating inflammatory response and triggering more IEC death. However, the precise intracellular machinery that prevents IEC death and break this vicious feedback remains largely unknown. Here, we report that Gab1 expression is decreased in patients with IBD and inversely correlated with IBD severity. Gab1 deficiency in intestinal epithelial cells accounts for the exacerbated colitis induced by dextran sodium sulfate (DSS) owing to sensitizing IECs to RIPK3-mediated necroptosis, which irreversibly disrupted homeostasis of the epithelial barrier and promoted intestinal inflammation. Mechanistically, Gab1 negatively regulates necroptosis signaling through inhibiting the formation of RIPK1/RIPK3 complex in response to TNF-α. Importantly, administration of RIPK3 inhibitor reveals a curative effect in epithelial Gab1-deficient mice. Further analysis indicates mice with Gab1 deletion are prone to inflammation associated colorectal tumorigenesis. Collectively, our study defines a protective role for Gab1 in colitis and colitis-driven colorectal cancer through negatively regulating RIPK3-dependent necroptosis, in which may serve as an important target to fine-tune necroptosis and intestinal inflammation-related disease.
Jiaqi Xu, Shihao Li, Wei Jin, Hui Zhou, Tingting Zhong, Xiaoqing Cheng, Yujuan Fu, Peng Xiao, Hongqiang Cheng, Di Wang, Yuehai Ke, Zhinong Jiang, Xue Zhang
Low CC16 plasma levels are linked to accelerated lung function decline in COPD patients. Cigarette smoke (CS)-exposed Cc16-/- mice have exaggerated COPD-like disease associated with increased NF-kB activation in their lungs. It is unclear whether CC16 augmentation can reverse exaggerated COPD in CS-exposed Cc16-/- mice and whether increased NF-kB activation contributes to the exaggerated COPD in CS-exposed Cc16-/- lungs. CS-exposed WT and Cc16-/- mice were treated with recombinant human CC16 protein solution (rhCC16) or a NF-kB inhibitor (IMD0354) versus vehicle beginning at the mid-point of the exposures. COPD-like disease and NF-kB activation were measured in the lungs. RhCC16 limited the progression of emphysema, small airway fibrosis, and chronic-bronchitis-like disease in WT and Cc16-/- mice partly by reducing pulmonary inflammation (reducing myeloid leukocytes and/or increasing regulatory T and/or B cells) and alveolar septal cell apoptosis, reducing NF-kB activation in CS-exposed Cc16-/- lungs, and rescuing the reduced Foxj1 expression in CS-exposed Cc16-/- lungs. IMD0354 treatment reduced exaggerated lung inflammation and rescued the reduced Foxj1 expression in CS-exposed Cc16-/- mice. rhCC16 treatment reduced NF-kB activation in luciferase reporter A549 cells. Thus, rhCC16 treatment limits COPD progression in CS-exposed Cc16-/- mice partly by inhibiting NF-kB activation and represents a novel therapeutic approach for COPD.
Joselyn Rojas-Quintero, Maria E. Laucho-Contreras, Xiaoyun Wang, Quynh-Anh Fucci, Patrick R. Burkett, Se-Jin Kim, Duo Zhang, Yohannes Tesfaigzi, Yuhong Li, Abhiram R. Bhashyam, Li Zhang, Haider Khamas, Bartolome Celli, Aprile L. Pilon, Francesca Polverino, Caroline A. Owen
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