Gastroenterologies
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
Abstract
Microvillus Inclusion Disease (MVID), caused by loss-of-function mutations in the motor protein Myosin Vb (MYO5B), is a severe infantile disease characterized by diarrhea, malabsorption, and acid-base instability, requiring intensive parenteral support for nutritional and fluid management. Human patient-derived enteroids represent a model for investigation of monogenic epithelial disorders but are a rare resource from MVID patients. We developed human enteroids with different loss-of function MYO5B variants and showed that they recapitulated the structural changes found in native MVID enterocytes. Multiplex Immunofluorescence imaging of patient duodenal tissues revealed patient-specific changes in localization of brush border transporters. Functional analysis of electrolyte transport revealed profound loss of Na+/H+ exchange (NHE) activity in MVID patient enteroids with near-normal chloride secretion. The chloride channel-blocking anti-diarrheal drug, Crofelemer, dose-dependently inhibited agonist-mediated fluid secretion. MVID enteroids exhibited altered differentiation and maturation versus healthy enteroids. Gamma-secretase inhibition with DAPT recovered apical brush border structure and functional Na+/H+ exchange activity in MVID enteroids. Transcriptomic analysis revealed potential pathways involved in the rescue of MVID cells including serum- and glucocorticoid-induced protein kinase 2 (SGK2), and NHE regulatory factor 3 (NHERF3). These results demonstrate the utility of patient-derived enteroids for developing therapeutic approaches to MVID.
Authors
Meri Kalashyan, Krishnan Raghunathan, Haley Oller, Marie-Theres Bayer, Lissette Jimenez, Joseph T. Roland, Elena Kolobova, Susan J. Hagen, Jeffrey D. Goldsmith, Mitchell D. Shub, James R. Goldenring, Izumi Kaji, Jay R. Thiagarajah
Abstract
The gastrointestinal tract relies on the production, maturation, and transit of mucin to protect against pathogens and to lubricate the epithelial lining. Although the molecular and cellular mechanisms that regulate mucin production and movement are beginning to be understood, the upstream epithelial signals that contribute to mucin regulation remain unclear. Here, we report that the inflammatory cytokine tumor necrosis factor (TNF), generated by the epithelium, contributes to mucin homeostasis by regulating both cell differentiation and cystic fibrosis transmembrane conductance regulator (CFTR) activity. We used genetic mouse models and non-inflamed samples from Inflammatory Bowel Disease (IBD) patients undergoing anti-TNF therapy to assess the effect of in vivo perturbation of TNF. We found that inhibition of epithelial TNF promotes the differentiation of secretory progenitor cells into mucus-producing goblet cells. Furthermore, TNF treatment and CFTR inhibition in intestinal organoids demonstrated that TNF promotes ion transport and luminal flow via CFTR. The absence of TNF led to slower gut transit times, which we propose results from increased mucus accumulation coupled with decreased luminal fluid pumping. These findings point to a TNF-CFTR signaling axis in the adult intestine and identify epithelial-derived TNF as an upstream regulator of mucin homeostasis.
Authors
Efren A. Reyes, David Castillo-Azofeifa, Jérémie Rispal, Tomas Wald, Rachel K. Zwick, Brisa Palikuqi, Angela Mujukian, Shervin Rabizadeh, Alexander R. Gupta, James M. Gardner, Dario Boffelli, Zev J. Gartner, Ophir D. Klein
Abstract
Colorectal cancer (CRC) at advanced stages is rarely curable, underscoring the importance of exploring the mechanism of CRC progression and invasion. NOD-like receptor family member NLRP12 was shown to suppress colorectal tumorigenesis, but the precise mechanism was unknown. Here we demonstrate that invasive adenocarcinoma development in Nlrp12-deficient mice is associated with elevated expression of genes involved in proliferation, matrix degradation, and epithelial-to-mesenchymal transition (EMT). Signaling pathway analysis revealed higher activation of the Wnt/β-catenin pathway, but not NF-kB and MAPK pathways, in the Nlrp12-deficient tumors. Using Nlrp12 conditional knockout mice, we confirmed that NLRP12 regulates tumorigenesis, invasiveness, and β-catenin activation in an intestinal epithelial cell-specific manner. In corroboration, NLRP12 deficiency made CRC cells or organoids hyperproliferative. With proteomic studies, we identified STK38 as a novel interacting partner of NLRP12 involved in the inhibition of phosphorylation of GSK3β, leading to the degradation of β-catenin. Consistently, the expression of NLRP12 was significantly reduced while phospho-GSK3β and β-catenin were upregulated in mouse and human colorectal tumor tissues. In summary, NLRP12 is a potent negative regulator of the Wnt/β-catenin pathway, and the NLRP12-STK38-GSK3β signaling axis could be a promising therapeutic target for CRC.
Authors
Shahanshah Khan, Youn-Tae Kwak, Lan Peng, Shuiqing Hu, Brandi L. Cantarel, Cheryl M. Lewis, Yunpeng Gao, Ram S. Mani, Thirumala-Devi Kanneganti, Hasan Zaki
Abstract
The liver can fully regenerate after partial resection and its underlying mechanisms have been extensively studied. The liver can also rapidly regenerate after injury with most studies focusing on hepatocyte proliferation; however, how hepatic necrotic lesions during acute or chronic liver diseases are eliminated and repaired remains obscure. Here we demonstrated that monocyte-derived macrophages (MoMFs) were rapidly recruited to and encapsulate necrotic areas during immune-mediated liver injury, and this feature was essential in repairing necrotic lesions. At the early stage of injury, infiltrating MoMFs activated the JAG1-NOTCH2 axis to induce cell death-resistant SOX9+ hepatocytes near the necrotic lesions, which acted as a barrier from further injury. Subsequently, necrotic environment (hypoxia and dead cells) induced a cluster of C1q+MoMFs that promoted necrotic removal and liver repair, while Pdgfb+MoMFs activated hepatic stellate cells (HSCs) to express -smooth muscle actin and induce a strong contraction signal (YAP, pMLC) to squeeze and finally eliminate the necrotic lesions. In conclusion, MoMFs play a key role in repairing the necrotic lesions not only by removing necrotic tissues but also by inducing cell death resistant hepatocytes to form a perinecrotic capsule and by activating α-smooth actin expressing HSCs to facilitate necrotic lesion resolution.
Authors
Dechun Feng, Xiaogang Xiang, Yukun Guan, Adrien Guillot, Hongkun Lu, Chingwen Chang, Yong He, Hua Wang, Hongna Pan, Cynthia Ju, Sean P. Colgan, Frank Tacke, Xin Wei Wang, George Kunos, Bin Gao
Abstract
Although selenium deficiency correlates with colorectal cancer (CRC) risk, the roles of the selenium-rich antioxidant selenoprotein P (SELENOP) in CRC remain unclear. In this study, we defined SELENOP’s contributions to sporadic colorectal carcinogenesis. In human scRNA-seq datasets, we discovered that SELENOP expression rises as normal colon stem cells transform into adenomas that progress into carcinomas. We next examined the effects of Selenop KO in a mouse adenoma model that involves conditional, intestinal epithelial-specific deletion of the tumor suppressor adenomatous polyposis coli (Apc) and found that Selenop KO decreased colon tumor incidence and size. We mechanistically interrogated SELENOP-driven phenotypes in tumor organoids as well as CRC and noncancer cell lines. Selenop KO tumor organoids demonstrated defects in organoid formation and decreases in WNT target gene expression, which could be reversed by SELENOP restoration. Moreover, SELENOP increased canonical WNT signaling activity in noncancer and CRC cell lines. In defining SELENOP’s mechanism of action, we mapped protein-protein interactions between SELENOP and the WNT co-receptor low-density lipoprotein receptor-related protein 5/6 (LRP5/6). Lastly, we confirmed that SELENOP:LRP5/6 interactions contributed to SELENOP’s effects on WNT activity. Overall, our results position SELENOP as a modulator of the WNT signaling pathway in sporadic CRC.
Authors
Jennifer M. Pilat, Rachel E. Brown, Zhengyi Chen, Nathaniel J. Berle, Adrian P. Othon, M. Washington, Shruti A. Anant, Suguru Kurokawa, Victoria H. Ng, Joshua J. Thompson, Justin Jacobse, Jeremy A. Goettel, Ethan Lee, Yash A. Choksi, Ken S. Lau, Sarah P. Short, Christopher S. Williams
Copyright © 2023 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)