Wei X, Zhang L, Zhou Z, Kwon OJ, Zhang Y, Nguyen H, Dumpit R, True L, Nelson P, Dong B, Xue W, Birchmeier W, Taketo MM, Xu F, Creighton CJ, Ittmann MM, Xin L.
PMID: 30982770 | DOI: 10.1016/j.stem.2019.03.010
Cell-autonomous Wnt signaling has well-characterized functions in controlling stem cell activity, including in the prostate. While niche cells secrete Wnt ligands, the effects of Wnt signaling in niche cells per se are less understood. Here, we show that stromal cells in the proximal prostatic duct near the urethra, a mouse prostate stem cell niche, not only produce multiple Wnt ligands but also exhibit strong Wnt/β-catenin activity. The non-canonical Wnt ligand Wnt5a, secreted by proximal stromal cells, directly inhibits proliefration of prostate epithelial stem or progenitor cells whereas stromal cell-autonomous canonical Wnt/β-catenin signaling indirectly suppresses prostate stem or progenitor activity via the transforming growth factor β (TGFβ) pathway. Collectively, these pathways restrain the proliferative potential of epithelial cells in the proximal prostatic ducts. Human prostate likewise exhibits spatially restricted distribution of stromal Wnt/β-catenin activity, suggesting a conserved mechanism for tissue patterning. Thus, this study shows how distinct stromal signaling mechanisms within the prostate cooperate to regulate tissue homeostasis.
Walter, RJ;Sonnentag, SJ;Munoz-Sagredo, L;Merkel, M;Richert, L;Bunert, F;Heneka, YM;Loustau, T;Hodder, M;Ridgway, RA;Sansom, OJ;Mely, Y;Rothbauer, U;Schmitt, M;Orian-Rousseau, V;
PMID: 35190527 | DOI: 10.1038/s41419-022-04607-0
Enhancement of Wnt signaling is fundamental for stem cell function during intestinal regeneration. Molecular modules control Wnt activity by regulating signal transduction. CD44 is such a positive regulator and a Wnt target gene. While highly expressed in intestinal crypts and used as a stem cell marker, its role during intestinal homeostasis and regeneration remains unknown. Here we propose a CD44 positive-feedback loop that boosts Wnt signal transduction, thus impacting intestinal regeneration. Excision of Cd44 in Cd44fl/fl;VillinCreERT2 mice reduced Wnt target gene expression in intestinal crypts and affected stem cell functionality in organoids. Although the integrity of the intestinal epithelium was conserved in mice lacking CD44, they were hypersensitive to dextran sulfate sodium, and showed more severe inflammation and delayed regeneration. We localized the molecular function of CD44 at the Wnt signalosome, and identified novel DVL/CD44 and AXIN/CD44 complexes. CD44 thus promotes optimal Wnt signaling during intestinal regeneration.
A cellular and spatial map of the choroid plexus across brain ventricles and ages
Dani, N;Herbst, RH;McCabe, C;Green, GS;Kaiser, K;Head, JP;Cui, J;Shipley, FB;Jang, A;Dionne, D;Nguyen, L;Rodman, C;Riesenfeld, SJ;Prochazka, J;Prochazkova, M;Sedlacek, R;Zhang, F;Bryja, V;Rozenblatt-Rosen, O;Habib, N;Regev, A;Lehtinen, MK;
PMID: 33932339 | DOI: 10.1016/j.cell.2021.04.003
The choroid plexus (ChP) in each brain ventricle produces cerebrospinal fluid (CSF) and forms the blood-CSF barrier. Here, we construct a single-cell and spatial atlas of each ChP in the developing, adult, and aged mouse brain. We delineate diverse cell types, subtypes, cell states, and expression programs in epithelial and mesenchymal cells across ages and ventricles. In the developing ChP, we predict a common progenitor pool for epithelial and neuronal cells, validated by lineage tracing. Epithelial and fibroblast cells show regionalized expression by ventricle, starting at embryonic stages and persisting with age, with a dramatic transcriptional shift with maturation, and a smaller shift in each aged cell type. With aging, epithelial cells upregulate host-defense programs, and resident macrophages upregulate interleukin-1β (IL-1β) signaling genes. Our atlas reveals cellular diversity, architecture and signaling across ventricles during development, maturation, and aging of the ChP-brain barrier.
Gastrointestinal Pathology in Samples from Coronavirus Disease 2019 (COVID-19)-Positive Patients
Archives of pathology & laboratory medicine
Westerhoff, M;Jones, D;Hrycaj, SM;Chan, MP;Pantanowitz, L;Tu, H;Choi, K;Greenson, J;Lamps, L;
PMID: 33961007 | DOI: 10.5858/arpa.2021-0137-SA
-Although primarily considered a respiratory illness, coronavirus disease 2019 (COVID-19) can cause gastrointestinal manifestations. -To evaluate histopathology and in situ hybridization for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in gastrointestinal samples from patients with recent and remote COVID-19. -Patients with positive SARS-CoV-2 nasopharyngeal tests and a gastrointestinal tissue specimen were included. SARS-CoV-2 in situ hybridization (ISH) was performed on each sample. A subset had SARS-CoV-2 next generation sequencing (NGS) performed. -Twenty-five patients met inclusion criteria. Five had positive SARS-CoV-2 nasopharyngeal tests within 7 days of their gastrointestinal procedure. Two were ulcerative colitis patients on steroid therapy who lacked typical COVID-19 symptoms. Their colectomies showed severe ulcerative colitis; one demonstrated SARS-CoV-2 by NGS but a negative ISH. Another had an ischemic colon resected as a complication of the COVID-19 course; however, both ISH and NGS were negative. A fourth had a normal-appearing terminal ileum but positive ISH and NGS. The fifth patient had ileal ulcers with SARS-CoV-2 negativity by both modalities. The remaining 20 patients had positive nasopharyngeal tests an average of 53 days prior to procedure. None of their samples demonstrated SARS-CoV-2 ISH positivity, but one was positive on NGS despite a negative nasopharyngeal test. -Gastrointestinal findings from SARS-CoV-2-infected patients ranged from normal with virus detected by ISH and NGS, to bowel ischemia secondary to systemic viral effects, without evidence of virus in the tissue. No distinct histologic finding was identified in those with gastrointestinal tissue specimens demonstrating SARS-CoV-2 positivity in this cohort.
Cell fate analysis of zone 3 hepatocytes in liver injury and tumorigenesis
Kurosaki, S;Nakagawa, H;Hayata, Y;Kawamura, S;Matsushita, Y;Yamada, T;Uchino, K;Hayakawa, Y;Suzuki, N;Hata, M;Tsuboi, M;Kinoshita, H;Tanaka, Y;Nakatsuka, T;Hirata, Y;Tateishi, K;Koike, K;
| DOI: 10.1016/j.jhepr.2021.100315
Background and aims Liver lobules are typically subdivided into three metabolic zones: zones 1, 2, and 3. However, the contribution of zonal differences in hepatocytes to liver regeneration, as well as to carcinogenic susceptibility, remains unclear. Methods We developed a new method for sustained genetic labeling of zone 3 hepatocytes and performed fate tracing to monitor these cells in multiple mouse liver tumor models. Results We first examined changes in the zonal distribution of the Wnt target gene Axin2 over time using Axin2-CreERT2;Rosa26-Lox-Stop-Lox-tdTomato mice (Axin2;tdTomato). We found that following tamoxifen administration at 3 weeks of age, approximately one-third of total hepatocytes that correspond to zone 3 were labeled in Axin2;tdTomato mice; the tdTomato+ cell distribution closely matched that of the zone 3 marker CYP2E1. Cell fate analysis revealed that zone 3 hepatocytes maintained their own lineage but rarely proliferated beyond their liver zonation during homeostasis; this indicated that our protocol enabled persistent genetic labeling of zone 3 hepatocytes. Using this system, we found that zone 3 hepatocytes generally had high neoplastic potential, which was promoted by constitutive activation of Wnt/β-catenin signaling in the pericentral area. However, the frequency of zone 3 hepatocyte-derived tumors varied depending on the regeneration pattern of the liver parenchyma in response to liver injury. Notably, Axin2-expressing hepatocytes undergoing chronic liver injury significantly contributed to liver regeneration and possessed high neoplastic potential. Additionally, we revealed that the metabolic phenotypes of liver tumors were acquired during tumorigenesis, irrespective of their spatial origin. Conclusions Hepatocytes receiving Wnt/β-catenin signaling from their microenvironment have high neoplastic potential, and Wnt/β-catenin signaling is a potential drug target for the prevention of hepatocellular carcinoma.
Signal transduction and targeted therapy
Song, Z;Bao, L;Deng, W;Liu, J;Ren, E;Lv, Q;Liu, M;Qi, F;Chen, T;Deng, R;Li, F;Liu, Y;Wei, Q;Gao, H;Yu, P;Han, Y;Zhao, W;Zheng, J;Liang, X;Yang, F;Qin, C;
PMID: 35091528 | DOI: 10.1038/s41392-022-00891-6
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted on mink farms between minks and humans in many countries. However, the systemic pathological features of SARS-CoV-2-infected minks are mostly unknown. Here, we demonstrated that minks were largely permissive to SARS-CoV-2, characterized by severe and diffuse alveolar damage, and lasted at least 14 days post inoculation (dpi). We first reported that infected minks displayed multiple organ-system lesions accompanied by an increased inflammatory response and widespread viral distribution in the cardiovascular, hepatobiliary, urinary, endocrine, digestive, and immune systems. The viral protein partially co-localized with activated Mac-2+ macrophages throughout the body. Moreover, we first found that the alterations in lipids and metabolites were correlated with the histological lesions in infected minks, especially at 6 dpi, and were similar to that of patients with severe and fatal COVID-19. Particularly, altered metabolic pathways, abnormal digestion, and absorption of vitamins, lipids, cholesterol, steroids, amino acids, and proteins, consistent with hepatic dysfunction, highlight metabolic and immune dysregulation. Enriched kynurenine in infected minks contributed to significant activation of the kynurenine pathway and was related to macrophage activation. Melatonin, which has significant anti-inflammatory and immunomodulating effects, was significantly downregulated at 6 dpi and displayed potential as a targeted medicine. Our data first illustrate systematic analyses of infected minks to recapitulate those observations in severe and fetal COVID-19 patients, delineating a useful animal model to mimic SARS-CoV-2-induced systematic and severe pathophysiological features and provide a reliable tool for the development of effective and targeted treatment strategies, vaccine research, and potential biomarkers.
Vanderheiden, A;Thomas, J;Soung, AL;Davis-Gardner, ME;Floyd, K;Jin, F;Cowan, DA;Pellegrini, K;Shi, PY;Grakoui, A;Klein, RS;Bosinger, SE;Kohlmeier, JE;Menachery, VD;Suthar, MS;
PMID: 34749524 | DOI: 10.1128/mBio.02749-21
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a historic pandemic of respiratory disease (coronavirus disease 2019 [COVID-19]), and current evidence suggests that severe disease is associated with dysregulated immunity within the respiratory tract. However, the innate immune mechanisms that mediate protection during COVID-19 are not well defined. Here, we characterize a mouse model of SARS-CoV-2 infection and find that early CCR2 signaling restricts the viral burden in the lung. We find that a recently developed mouse-adapted SARS-CoV-2 (MA-SARS-CoV-2) strain as well as the emerging B.1.351 variant trigger an inflammatory response in the lung characterized by the expression of proinflammatory cytokines and interferon-stimulated genes. Using intravital antibody labeling, we demonstrate that MA-SARS-CoV-2 infection leads to increases in circulating monocytes and an influx of CD45+ cells into the lung parenchyma that is dominated by monocyte-derived cells. Single-cell RNA sequencing (scRNA-Seq) analysis of lung homogenates identified a hyperinflammatory monocyte profile. We utilize this model to demonstrate that mechanistically, CCR2 signaling promotes the infiltration of classical monocytes into the lung and the expansion of monocyte-derived cells. Parenchymal monocyte-derived cells appear to play a protective role against MA-SARS-CoV-2, as mice lacking CCR2 showed higher viral loads in the lungs, increased lung viral dissemination, and elevated inflammatory cytokine responses. These studies have identified a potential CCR2-monocyte axis that is critical for promoting viral control and restricting inflammation within the respiratory tract during SARS-CoV-2 infection. IMPORTANCE SARS-CoV-2 has caused a historic pandemic of respiratory disease (COVID-19), and current evidence suggests that severe disease is associated with dysregulated immunity within the respiratory tract. However, the innate immune mechanisms that mediate protection during COVID-19 are not well defined. Here, we characterize a mouse model of SARS-CoV-2 infection and find that early CCR2-dependent infiltration of monocytes restricts the viral burden in the lung. We find that SARS-CoV-2 triggers an inflammatory response in the lung characterized by the expression of proinflammatory cytokines and interferon-stimulated genes. Using RNA sequencing and flow cytometry approaches, we demonstrate that SARS-CoV-2 infection leads to increases in circulating monocytes and an influx of CD45+ cells into the lung parenchyma that is dominated by monocyte-derived cells. Mechanistically, CCR2 signaling promoted the infiltration of classical monocytes into the lung and the expansion of monocyte-derived cells. Parenchymal monocyte-derived cells appear to play a protective role against MA-SARS-CoV-2, as mice lacking CCR2 showed higher viral loads in the lungs, increased lung viral dissemination, and elevated inflammatory cytokine responses. These studies have identified that the CCR2 pathway is critical for promoting viral control and restricting inflammation within the respiratory tract during SARS-CoV-2 infection.
Am J Respir Crit Care Med. 2018 Dec 15.
Reyfman PA, Walter JM, Joshi N, Anekalla KR, McQuattie-Pimentel AC, Chiu S, Fernandez R, Akbarpour M, Chen CI, Ren Z, Verma R, Abdala-Valencia H, Nam K, Chi M, Han S, Gonzalez-Gonzalez FJ, Soberanes S, Watanabe S, Williams KJN, Flozak AS, Nicholson TT, Morgan VK, Winter DR, Hinchcliff M, Hrusch CL, Guzy RD, Bonham CA, Sperling AI, Bag R, Hamanaka RB, Mutlu GM, Yeldandi AV, Marshall SA, Shilatifard A, Amaral LAN, Perlman H, Sznajder JI, Argento AC, Gillespie CT, Dematte J, Jain M, Singer BD, Ridge KM, Lam AP, Bharat A, Bhorade SM, Gottardi CJ, Budinger GRS, Misharin AV.
PMID: 30554520 | DOI: 10.1164/rccm.201712-2410OC
Abstract RATIONALE: The contributions of diverse cell populations in the human lung to pulmonary fibrosis pathogenesis are poorly understood. Single-cell RNA sequencing can reveal changes within individual cell populations during pulmonary fibrosis that are important for disease pathogenesis. OBJECTIVES: To determine whether single-cell RNA sequencing can reveal disease-related heterogeneity within alveolar macrophages, epithelial cells or other cell types in lung tissue from subjects with pulmonary fibrosis compared with controls. METHODS: We performed single-cell RNA sequencing on lung tissue obtained from eight transplant donors and eight recipients with pulmonary fibrosis and on one bronchoscopic cryobiospy sample from a patient with idiopathic pulmonary fibrosis. We validated these data in using in situ RNA hybridization, immunohistochemistry, and bulk RNA-sequencing on flow-sorted cells from 22 additional subjects. MEASUREMENTS AND MAIN RESULTS: We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to non-overlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. We developed a web-based tool to explore these data. CONCLUSIONS: We generated a single cell atlas of pulmonary fibrosis. Using this atlas we demonstrated heterogeneity within alveolar macrophages and epithelial cells from subjects with pulmonary fibrosis. These results support the feasibility of discovery-based approaches using next generation sequencing technologies to identify signaling pathways for targeting in the development of personalized therapies for patients with pulmonary fibrosis.
Hou Z, Wu Q, Sun X, Chen H, Li Y, Zhang Y, Mori M, Yang Y, Que J, Jiang M.
PMID: 30696710 | DOI: 10.1242/dev.171496
Basal progenitor cells are critical for the establishment and maintenance of the tracheal epithelium. However, it remains unclear how these progenitor cells are specified during foregut development. Here, we found that ablation of the Wnt chaperon protein Gpr177 (also known as Wntless) in the epithelium causes the significant reduction in the numbers of basal progenitor cells accompanied by cartilage loss in Shh-Cre;Gpr177 loxp/loxp mutants. Consistent with the association between cartilage and basal cell development, Nkx2.1+p63+ basal cells are co-present with cartilage nodules in Shh-Cre;Ctnnb1 DM/loxp mutants which keep partial cell-cell adhesion but not the transcription regulation function of ß-catenin. More importantly, deletion of Ctnnb1 in the mesenchyme leads to the loss of basal cells and cartilage concomitant with the reduced transcript levels of Fgf10 in Dermo1-Cre;Ctnnb1 loxp/loxp mutants. Furthermore, deletion of Fgf receptor 2 (Fgfr2) in the epithelium also leads to significantly reduced numbers of basal cells, supporting the importance of the Wnt/Fgf crosstalk in early tracheal development.
Pepe-Mooney BJ, Dill MT, Alemany A, Ordovas-Montanes J, Matsushita Y, Rao A, Sen A, Miyazaki M, Anakk S, Dawson PA, Ono N, Shalek AK, van Oudenaarden A, Camargo FD.
PMID: 31080134 | DOI: 10.1016/j.stem.2019.04.004
The liver can substantially regenerate after injury, with both main epithelial cell types, hepatocytes and biliary epithelial cells (BECs), playing important roles in parenchymal regeneration. Beyond metabolic functions, BECs exhibit substantial plasticity and in some contexts can drive hepatic repopulation. Here, we performed single-cell RNA sequencing to examine BEC and hepatocyte heterogeneity during homeostasisand after injury. Instead of evidence for a transcriptionally defined progenitor-like BEC cell, we found significant homeostatic BEC heterogeneity that reflects fluctuating activation of a YAP-dependent program. This transcriptional signature defines a dynamic cellular state during homeostasis and is highly responsive to injury. YAP signaling is induced by physiological bile acids (BAs), required for BEC survival in response to BA exposure, and is necessary for hepatocyte reprogramming into biliary progenitors upon injury. Together, these findings uncover molecular heterogeneity within the ductal epithelium and reveal YAP as a protective rheostat and regenerative regulator in the mammalian liver.
Wilson DH, Jarman EJ, Mellin RP, Wilson ML, Waddell SH, Tsokkou P, Younger NT, Raven A, Bhalla SR, Noll ATR, Olde Damink SW, Schaap FG, Chen P, Bates DO, Banales JM, Dean CH, Henderson DJ, Sansom OJ, Kendall TJ, Boulter L
PMID: 31974352 | DOI: 10.1038/s41467-020-14283-3
The number of patients diagnosed with chronic bile duct disease is increasing and in most cases these diseases result in chronic ductular scarring, necessitating liver transplantation. The formation of ductular scaring affects liver function; however, scar-generating portal fibroblasts also provide important instructive signals to promote the proliferation and differentiation of biliary epithelial cells. Therefore, understanding whether we can reduce scar formation while maintaining a pro-regenerative microenvironment will be essential in developing treatments for biliary disease. Here, we describe how regenerating biliary epithelial cells express Wnt-Planar Cell Polarity signalling components following bile duct injury and promote the formation of ductular scars by upregulating pro-fibrogenic cytokines and positively regulating collagen-deposition. Inhibiting the production of Wnt-ligands reduces the amount of scar formed around the bile duct, without reducing the development of the pro-regenerative microenvironment required for ductular regeneration, demonstrating that scarring and regeneration can be uncoupled in adult biliary disease and regeneration
Röltgen, K;Nielsen, S;Silva, O;Younes, S;Maxim Zaslavsky, ;Costales, C;Yang, F;Wirz, O;Solis, D;Hoh, R;Wang, A;Arunachalam, P;Colburg, D;Zhao, S;Haraguchi, E;Lee, A;Shah, M;Manohar, M;Chang, I;Gao, F;Mallajosyula, V;Li, C;Liu, J;Shoura, M;Sindher, S;Parsons, E;Dashdorj, N;Dashdorj, N;Monroe, R;Serrano, G;Beach, T;Chinthrajah, R;Charville, G;Wilbur, J;Wohlstadter, J;Davis, M;Pulendran, B;Troxell, M;Sigal, G;Natkunam, Y;Pinsky, B;Nadeau, K;Boyd, S;
| DOI: 10.1016/j.cell.2022.01.018
During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including 3rd dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is less after infection compared to all vaccines evaluated, but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks post-vaccination in some cases. SARS-CoV-2 antibody specificity, breadth and maturation are affected by imprinting from exposure history, and distinct histological and antigenic contexts in infection compared to vaccination.
