Gastroenterology
Abstract
Epigenetic regulatory mechanisms are underappreciated, yet are critical for enteric nervous system (ENS) development and maintenance. We discovered that fetal loss of the epigenetic regulator Bap1 in the ENS lineage caused severe postnatal bowel dysfunction and early death in Tyrosinase-Cre Bap1fl/fl mice. Bap1-depleted ENS appeared normal in neonates; however, by P15, Bap1-deficient enteric neurons were largely absent from the small and large intestine of Tyrosinase-Cre Bap1fl/fl mice. Bowel motility became markedly abnormal with disproportionate loss of cholinergic neurons. Single-cell RNA sequencing at P5 showed that fetal Bap1 loss in Tyrosinase-Cre Bap1fl/fl mice markedly altered the composition and relative proportions of enteric neuron subtypes. In contrast, postnatal deletion of Bap1 did not cause enteric neuron loss or impaired bowel motility. These findings suggest that BAP1 is critical for postnatal enteric neuron differentiation and for early enteric neuron survival, a finding that may be relevant to the recently described human BAP1-associated neurodevelopmental disorder.
Authors
Sabine Schneider, Jessica B. Anderson, Rebecca P. Bradley, Katherine Beigel, Christina M. Wright, Beth A. Maguire, Guang Yan, Deanne M. Taylor, J. William Harbour, Robert O. Heuckeroth
Abstract
Bacterial translocation from the gut microbiota is a source of sepsis in susceptible patients. Previous work suggests that overgrowth of gut pathobionts, including Klebsiella pneumoniae, increases the risk of disseminated infection. Our data from a human dietary intervention study found that in the absence of fiber, K. pneumoniae bloomed during microbiota recovery from antibiotic treatment. We thus hypothesized that dietary nutrients directly support or suppress colonization of this gut pathobiont in the microbiota. Consistent with our human subject study, complex carbohydrates in dietary fiber suppressed colonization of K. pneumoniae and allowed for recovery of competing commensals in mouse modeling. In contrast, through ex-vivo and in vivo modeling, we identify simple carbohydrates as a limiting resource for K. pneumoniae in the gut. As proof of principle, supplementation with lactulose, a non-absorbed simple carbohydrate and an FDA approved therapy, increased colonization of K. pneumoniae. Disruption of the intestinal epithelium led to dissemination of K. pneumoniae into the bloodstream and liver, which was prevented by dietary fiber. Our results show that dietary simple and complex carbohydrates are critical not only in the regulation of pathobiont colonization but also disseminated infection, suggesting that targeted dietary interventions may offer a preventative strategy in high-risk patients.
Authors
Aaron L. Hecht, Lisa C. Harling, Elliot S. Friedman, Ceylan Tanes, Junhee Lee, Jenni Firrman, Fuhua Hao, Vincent Tu, LinShu Liu, Andrew D. Patterson, Kyle Bittinger, Mark Goulian, Gary D. Wu
Abstract
Neutrophil (PMN) tissue accumulation is an established feature of ulcerative colitis (UC) lesions and colorectal cancer (CRC). To assess the PMN phenotypic and functional diversification during inflammatory ulceration to CRC transition we analyzed the transcriptomic landscape of blood and tissue PMNs. Transcriptional programs effectively separated PMNs based on their localization to peripheral blood, inflamed colon, and tumors. In silico pathway overrepresentation analysis, protein-network mapping, gene signature identification, and gene-ontology scoring revealed unique enrichment of angiogenic and vasculature development pathways in tumor-associated neutrophils (TANs). Functional studies utilizing ex vivo cultures, colitis-induced murine CRC, and patient-derived xenograft models demonstrated a critical role for TANs in promoting tumor vascularization. Spp1 (OPN) and Mmp14 (MT1-MMP) were identified by unbiased -omics and mechanistic studies to be highly induced in TANs, acting to critically regulate endothelial cell chemotaxis and branching. TCGA dataset and clinical specimens confirmed enrichment of SPP1 and MMP14 in high-grade CRC but not in UC patients. Pharmacological inhibition of TAN trafficking or MMP14 activity effectively reduced tumor vascular density, leading to CRC regression. Our findings, demonstrate a niche-directed PMN functional specialization, and identify TAN contributions to tumor vascularization, delineating a new therapeutic framework for CRC treatment focused on TAN angiogenic properties.
Authors
Triet M. Bui, Lenore K. Yalom, Edward Ning, Jessica M. Urbanczyk, Xingsheng Ren, Caroline J. Herrnreiter, Jackson A. DiSario, Brian Wray, Matthew J. Schipma, Yuri S. Velichko, David P. Sullivan, Kouki Abe, Shannon M. Lauberth, Guang-Yu Yang, Parambir S. Dulai, Stephen B. Hanauer, Ronen Sumagin
Abstract
BACKGROUND. The tumor immune microenvironment can provide prognostic and therapeutic information. We aimed to develop noninvasive imaging biomarkers from computed tomography (CT) for comprehensive evaluation of immune context, and investigate their associations with prognosis and immunotherapy response in gastric cancer (GC). METHODS. This study involved 2,600 GC patients of nine independent cohorts. We developed and validated two CT imaging biomarkers [lymphoid radiomics score (LRS) and myeloid radiomics score (MRS)] for evaluating the immunohistochemistry (IHC)-derived lymphoid and myeloid immune context respectively, and then integrated them into a combined imaging biomarker [LRS/MRS: low(−) or high(+)] with four radiomics immune subtypes: 1(−/−), 2(+/−), 3(−/+), and 4(+/+). We further evaluated the imaging biomarkers' predictive values on prognosis and immunotherapy response. RESULTS. The developed imaging biomarkers (LRS and MRS) had a high accuracy in predicting lymphoid (AUC range: 0.765-0.773) and myeloid (AUC range: 0.736-0.750) immune context. Furthermore, same as IHC-derived immune context, two imaging biomarkers (HR range: 0.240-0.761 for LRS; 1.301-4.012 for MRS) and the combined biomarker were independent predictors for disease-free and overall survival in the training and all validation cohorts (all P<0.05). In addition, patient with high LRS or low MRS may benefit more from immunotherapy (P<0.001). Furthermore, a highly heterogeneous outcome on objective response rate was observed in four imaging subtypes: 1(−/−) with 27.3%, 2(+/−) with 53.3%, 3(−/+) with 10.2%, and 4(+/+) with 30.0% (P<0.0001). CONCLUSION. The noninvasive imaging biomarkers could accurately evaluate the immune context, and provide information regarding prognosis and immunotherapy for GC. FUNDING. None
Authors
Zepang Sun, Taojun Zhang, M. Usman Ahmad, Zixia Zhou, Liang Qiu, Kangneng Zhou, Wenjun Xiong, Jingjing Xie, Zhicheng Zhang, Chuanli Chen, Qingyu Yuan, Yan Chen, Wanying Feng, Yikai Xu, Lequan Yu, Wei Wang, Jiang Yu, Guoxin Li, Yuming Jiang
Abstract
BACKGROUND. Improving and predicting tumor response to immunotherapy remains challenging. Combination therapy with a transforming growth factor-β receptor (TGF-βR) inhibitor that targets cancer associated fibroblasts (CAFs) is promising to enhance efficacy of immunotherapies. However, the effect of this approach in clinical trials is limited, requiring in vivo methods to better assess tumor responses to combination therapy. METHODS. We measure CAFs in vivo using 68Ga-labeled fibroblast activation protein inhibitor (68Ga-FAPI)-04 for PET/CT imaging to guide combination of TGF-β inhibition and immunotherapy. 131 patients with metastatic colorectal cancer (CRC) underwent 68Ga-FAPI and 18F-fludeoxyglucose (18F-FDG) PET/CT imaging. Relationship between uptake of 68Ga-FAPI and tumor immunity was analyzed in patients. Mouse cohorts of metastatic CRC were treated with TGF-βR inhibitor combined with KN046 which blocks PD-L1 and CTLA4, followed with 68Ga-FAPI and 18F-FDG micro-PET/CT imaging to assess tumor responses. RESULTS. Patients with metastatic CRC demonstrated high uptakes of 68Ga-FAPI, along with suppressive tumor immunity and poor prognosis. TGF-βR inhibitor enhanced tumor infiltrating T cells and significantly sensitized metastatic CRC to KN046. 68Ga-FAPI PET/CT imaging accurately monitored the dynamical changes of CAFs and tumor response to combined TGF-βR inhibitor with immunotherapy. CONCLUSION. 68Ga-FAPI PET/CT imaging is powerful in assessing tumor immunity and response to immunotherapy in metastatic CRC. This study supports future clinical application of 68Ga-FAPI PET/CT to guide CRC patients for precise TGF-β inhibition plus immunotherapy, recommending 68Ga-FAPI and 18F-FDG dual PET/CT for CRC management. TRIAL REGISTRATION. CFFSTS Trial, ChiCTR2100053984, Chinese Clinical Trial Registry. FUNDING. National Natural Science Foundation of China (82072695, 32270767, 82272035,81972260).
Authors
Ke Li, Wei Liu, Hang Yu, Jiwei Chen, Wenxuan Tang, Jianpeng Wang, Ming Qi, Yuyun Sun, Xiaoping Xu, Ji Zhang, Xinxiang Li, Weijian Guo, Xiaoling Li, Shaoli Song, Shuang Tang
Abstract
Targeted metagenomic sequencing is an emerging strategy to survey disease- specific microbiome biomarkers for clinical diagnosis and prognosis. However, this approach often yields inconsistent or conflicting results due to inadequate study power and sequencing bias. We introduce Taxa4Meta, a bioinformatics pipeline explicitly designed to compensate for technical and demographic bias. We designed and validated Taxa4Meta for accurate taxonomic profiling of 16S rRNA amplicon data acquired from different sequencing strategies. Taxa4Meta offers significant potential in identifying clinical dysbiotic features that can reliably predict human disease, validated comprehensively via re-analysis of individual patient 16S datasets. We leveraged the power of Taxa4Meta's pan-microbiome profiling to generate 16S-based classifiers that exhibited excellent utility for stratification of diarrheal patients with Clostridioides difficile infection, irritable bowel syndrome or inflammatory bowel diseases, which represent common misdiagnoses and pose significant challenges for clinical management. We believe that Taxa4Meta represents a new "best practices" approach to individual microbiome surveys that can be used to define gut dysbiosis at a population-scale level.
Authors
Qinglong Wu, Shyam Badu, Sik Yu So, Todd J. Treangen, Tor C. Savidge
Abstract
Cronkhite-Canada Syndrome (CCS) is a rare, noninherited polyposis syndrome affecting 1 in every million individuals. Despite over 50 years of CCS cases, the etiopathogenesis and optimal treatment for CCS remains unknown due to the rarity of the disease and lack of model systems. To better understand the etiology of CCS, we generated human intestinal organoids (HIOs) from intestinal stem cells isolated from 2 patients. We discovered that CCS HIOs are highly proliferative and have increased numbers of enteroendocrine cells producing serotonin (also known as 5-hydroxytryptamine or 5HT). These features were also confirmed in patient tissue biopsies. Recombinant 5HT increased proliferation of non-CCS donor HIOs and inhibition of 5HT production in the CCS HIOs resulted in decreased proliferation, suggesting a link between local epithelial 5HT production and control of epithelial stem cell proliferation. This link was confirmed in genetically engineered HIOs with an increased number of enteroendocrine cells. This work provides a new mechanism to explain the pathogenesis of CCS and illustrates the important contribution of HIO cultures to understanding disease etiology and in the identification of novel therapies. Our work demonstrates the principle of using organoids for personalized medicine and sheds light on how intestinal hormones can play a role in intestinal epithelial proliferation.
Authors
Victoria Poplaski, Carolyn Bomidi, Amal Kambal, Hoa Nguyen-Phuc, Sara C. Di Rienzi, Heather A. Danhof, Xi-Lei Zeng, Linda A. Feagins, Nan Deng, Eduardo Vilar, Florencia McAllister, Cristian Coarfa, Soyoun Min, Hyun Jung Kim, Richa Shukla, Robert Britton, Mary K. Estes, Sarah E. Blutt
Abstract
Inflammatory bowel disease (IBD) patients are susceptible to colitis-associated cancer (CAC). Chronic inflammation promotes the risk for CAC. In contrast, mucosal healing predicts improved prognosis in IBD and reduced risk of CAC. However, molecular integration between colitis, mucosal healing and CAC remains poorly understood. Claudin-2 (CLDN2) expression is upregulated in IBD, however, its role in CAC is not known. The current study was undertaken to examine the role for CLDN2 in CAC. The AOM/DSS-induced CAC model was used with wild type (WT), and CLDN2 modified mice. High-throughput expression analyses, murine models of colitis/recovery, chronic colitis, ex-vivo crypt culture and pharmacological manipulations were employed for mechanistic understanding. The Cldn2KO mice showed significant inhibition of CAC despite severe colitis compared to WT-littermates. Cldn2 loss also resulted in impaired recovery from colitis and increased injury when subjected to intestinal injury by other methods. Mechanistic studies demonstrated a novel role of CLDN2 in promoting mucosal healing downstream of EGFR-signaling and by regulating Survivin expression. An upregulated CLDN2 expression protected from CAC and associated positively with crypt regeneration and Survivin expression in IBD patients. We demonstrate a novel role of CLDN2 in promoting mucosal healing in IBD patients, and thus regulating vulnerability to colitis severity and CAC, which can be exploited for improved clinical management.
Authors
Rizwan Ahmad, Balawant Kumar, Ishwor Thapa, Raju Lama Tamang, Santosh Kumar Yadav, Mary K. Washington, Geoffrey A. Talmon, Alan S. Yu, Dhundy K. Bastola, Punita Dhawan, Amar B. Singh
Abstract
RECK is downregulated in various human cancers; however, how RECK inactivation affects carcinogenesis remains unclear. We addressed this issue in a pancreatic ductal adenocarcinoma (PDAC) mouse model and found that pancreatic Reck deletion dramatically augmented the spontaneous development of PDAC with a mesenchymal phenotype, which was accompanied by increased liver metastases and decreased survival. Lineage tracing revealed that pancreatic Reck deletion induced epithelial-mesenchymal transition (EMT) in PDAC cells, giving rise to inflammatory cancer-associated fibroblast–like cells in mice. Splenic transplantation of Reck-null PDAC cells resulted in numerous liver metastases with a mesenchymal phenotype, whereas reexpression of RECK markedly reduced metastases and changed the PDAC tumor phenotype into an epithelial one. Consistently, low RECK expression correlated with low E-cadherin expression, poor differentiation, metastasis, and poor prognosis in human PDAC. RECK reexpression in the PDAC cells was found to downregulate MMP2 and MMP3, with a concomitant increase in E-cadherin and decrease in EMT-promoting transcription factors. An MMP inhibitor recapitulated the effects of RECK on the expression of E-cadherin and EMT-promoting transcription factors and invasive activity. These results establish the authenticity of RECK as a pancreatic tumor suppressor, provide insights into its underlying mechanisms, and support the idea that RECK could be an important therapeutic effector against human PDAC.
Authors
Tomonori Masuda, Akihisa Fukuda, Go Yamakawa, Mayuki Omatsu, Mio Namikawa, Makoto Sono, Yuichi Fukunaga, Munemasa Nagao, Osamu Araki, Takaaki Yoshikawa, Satoshi Ogawa, Kenji Masuo, Norihiro Goto, Yukiko Hiramatsu, Yu Muta, Motoyuki Tsuda, Takahisa Maruno, Yuki Nakanishi, Toshihiko Masui, Etsuro Hatano, Tomoko Matsuzaki, Makoto Noda, Hiroshi Seno
Abstract
The metastasis of cancer cells is the main cause of death for patients with gastric cancer (GC). Mounting evidence has demonstrated the vital importance of tumor-associated macrophages in promoting tumor invasion and metastasis; however, the interaction between tumor cells and macrophages in GC is largely unknown. In this study, we demonstrated that cyclase-associated protein 2 (CAP2) was upregulated in GC, especially in cases with lymph node metastasis, and was correlated with a poorer prognosis. The transcription factor JUN directly bound to the promoter region of CAP2 and activated CAP2 transcription. The N-terminal domain of CAP2 bound to the WD5-7 domain of receptor for activated C kinase 1 (RACK1) and induced M2 macrophage polarization by activating the SRC/focal adhesion kinase (FAK)/ ERK signaling pathway, which resulted in interleukin-4 (IL4) and IL10 secretion. Polarized M2 macrophages induced premetastatic niche formation and promoted GC metastasis by secreting transforming growth factor beta (TGFB1), which created a TGFB1/JUN/CAP2-positive feedback loop to activate CAP2 expression continuously. Furthermore, we identified Salvianolic acid B as an inhibitor of CAP2, which effectively inhibited GC cell invasion capabilities by suppressing the SRC/FAK/ERK signaling pathway. Our data suggest that CAP2, a key molecule mediating the interaction between GC cells and tumor-associated macrophages, may be a promising therapeutic target for suppressing tumor metastasis in GC.
Authors
Guohao Zhang, Zhaoxin Gao, Xiangyu Guo, Ranran Ma, Xiaojie Wang, Pan Zhou, Chunlan Li, Zhiyuan Tang, Ruinan Zhao, Peng Gao
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)