Spatially organized multicellular immune hubs in human colorectal cancer
Pelka, K;Hofree, M;Chen, JH;Sarkizova, S;Pirl, JD;Jorgji, V;Bejnood, A;Dionne, D;Ge, WH;Xu, KH;Chao, SX;Zollinger, DR;Lieb, DJ;Reeves, JW;Fuhrman, CA;Hoang, ML;Delorey, T;Nguyen, LT;Waldman, J;Klapholz, M;Wakiro, I;Cohen, O;Albers, J;Smillie, CS;Cuoco, MS;Wu, J;Su, MJ;Yeung, J;Vijaykumar, B;Magnuson, AM;Asinovski, N;Moll, T;Goder-Reiser, MN;Applebaum, AS;Brais, LK;DelloStritto, LK;Denning, SL;Phillips, ST;Hill, EK;Meehan, JK;Frederick, DT;Sharova, T;Kanodia, A;Todres, EZ;Jané-Valbuena, J;Biton, M;Izar, B;Lambden, CD;Clancy, TE;Bleday, R;Melnitchouk, N;Irani, J;Kunitake, H;Berger, DL;Srivastava, A;Hornick, JL;Ogino, S;Rotem, A;Vigneau, S;Johnson, BE;Corcoran, RB;Sharpe, AH;Kuchroo, VK;Ng, K;Giannakis, M;Nieman, LT;Boland, GM;Aguirre, AJ;Anderson, AC;Rozenblatt-Rosen, O;Regev, A;Hacohen, N;
PMID: 34450029 | DOI: 10.1016/j.cell.2021.08.003
Immune responses to cancer are highly variable, with mismatch repair-deficient (MMRd) tumors exhibiting more anti-tumor immunity than mismatch repair-proficient (MMRp) tumors. To understand the rules governing these varied responses, we transcriptionally profiled 371,223 cells from colorectal tumors and adjacent normal tissues of 28 MMRp and 34 MMRd individuals. Analysis of 88 cell subsets and their 204 associated gene expression programs revealed extensive transcriptional and spatial remodeling across tumors. To discover hubs of interacting malignant and immune cells, we identified expression programs in different cell types that co-varied across tumors from affected individuals and used spatial profiling to localize coordinated programs. We discovered a myeloid cell-attracting hub at the tumor-luminal interface associated with tissue damage and an MMRd-enriched immune hub within the tumor, with activated T cells together with malignant and myeloid cells expressing T cell-attracting chemokines. By identifying interacting cellular programs, we reveal the logic underlying spatially organized immune-malignant cell networks.
Yap Promotes Noncanonical Wnt Signals from Cardiomyocytes for Heart Regeneration
Liu, S;Tang, L;Zhao, X;Nguyen, B;Heallen, TR;Li, M;Wang, J;Wang, J;Martin, JF;
PMID: 34424032 | DOI: 10.1161/CIRCRESAHA.121.318966
Rationale: During neonatal heart regeneration, the fibrotic response, which is required to prevent cardiac rupture, resolves via poorly understood mechanisms. Deletion of the Hippo pathway gene Sav in adult CMs increases Yap activity and promotes cardiac regeneration, partly by inducing fibrosis resolution. Deletion of Yap in neonatal cardiomyocytes (CMs) leads to increased fibrosis and loss of neonatal heart regeneration, suggesting that Yap inhibits fibrosis by regulating intercellular signaling from CMs to cardiac fibroblasts (CFs). Objective: We investigated the role of Wntless (Wls), which is a direct target gene of Yap, in communication between CMs and CFs during neonatal heart regeneration. Methods and Results: We generated two mouse models to delete Wls specifically in CMs (Myh6-Cas9 combined with AAV9-Wls-gRNAs, and Myh6cre-ERT2/+; Wlsflox/flox mouse). Reanalysis of single-cell RNA-sequencing data revealed that Wnt ligands are expressed in CMs, whereas Wnt receptors are expressed in CFs, suggesting that Wnt signaling is directional from CMs to CFs during neonatal heart regeneration. Wls deletion in neonatal hearts disrupted Wnt signaling, showing as reduced noncanonical Wnt signaling in non-CMs. Four weeks after neonatal heart infarction, heart function was measured by echocardiography. Wls deletion in neonatal hearts after myocardial infarction impairs neonatal heart regeneration, marked by decreased contractile function and increased fibrosis. Wls mutant hearts display CF activation, characterized by increased extracellular matrix secretion, inflammation, and CF proliferation. Conclusions: These data indicate that during neonatal heart regeneration, intercellular signaling from CMs to CFs occurs via noncanonical Wnt signaling to rebuild cardiac architecture after myocardial infarction.
Delta-like1-expressing cells at the gland base promote proliferation of gastric antral stem cells in mouse
Cellular and molecular gastroenterology and hepatology
Horita, N;Keeley, TM;Hibdon, ES;Delgado, E;Lafkas, D;Siebel, CW;Samuelson, LC;
PMID: 34438113 | DOI: 10.1016/j.jcmgh.2021.08.012
Notch pathway signaling maintains gastric epithelial cell homeostasis by regulating stem cell proliferation and differentiation. We previously identified NOTCH1 and NOTCH2 as the key Notch receptors controlling gastric stem cell function. Here, we identify the niche cells and critical Notch ligand responsible for regulating stem cell proliferation in the distal mouse stomach.Expression of Notch ligands in the gastric antrum was determined by qRT-PCR and cellular localization was determined by in situ hybridization and immunostaining. The contribution of specific Notch ligands to regulate epithelial cell proliferation in adult mice was determined by inducible gene deletion, or by pharmacologic inhibition using antibodies directed against specific Notch ligands. Mouse gastric organoid cultures were used to confirm that Notch ligand signaling was epithelial specific.DLL1 and JAG1 were the most abundantly expressed Notch ligands in the adult mouse stomach, with DLL1 restricted to the antral gland base, and JAG1 localized to the upper gland region. Inhibition of DLL1 alone or in combination with other Notch ligands significantly reduced epithelial cell proliferation and the growth of gastric antral organoids, while inhibition of the other Notch ligands, DLL4, JAG1 and JAG2, did not affect proliferation or organoid growth. Similarly, DLL1, and not DLL4, regulated proliferation of LGR5+ antral stem cells, which express the NOTCH1 receptor.DLL1 is the key Notch ligand regulating epithelial cell proliferation in the gastric antrum. We propose that DLL1-expressing cells at the gland base are Notch niche cells which signal to adjacent LGR5+ antral stem cells to regulate stem cell proliferation and epithelial homeostasis.
Activation of proneuronal transcription factor Ascl1 in maternal liver ensures a healthy pregnancy
Cellular and molecular gastroenterology and hepatology
Lee, J;Garcia, V;Nambiar, SM;Jiang, H;Dai, G;
PMID: 34438112 | DOI: 10.1016/j.jcmgh.2021.08.009
Maternal liver exhibits robust adaptations to pregnancy to accommodate the metabolic needs of developing and growing placenta and fetus by largely unknown mechanisms. We found that achaete-scute homolog-like 1 (Ascl1), a gene encoding a basic helix-loop-helix transcription factor essential for neuronal development, is highly activated in maternal hepatocytes during the second half of gestation in mice.To investigate whether and how Ascl1 plays a pregnancy-dependent role, we deleted the Ascl1 gene specifically in maternal hepatocytes from mid-gestation until term.As a result, we identified multiple Ascl1-dependent phenotypes. Maternal livers lacking Ascl1 exhibited aberrant hepatocyte structure, increased hepatocyte proliferation, enlarged hepatocyte size, reduced albumin production, and elevated release of liver enzymes, indicating maternal liver dysfunction. Simultaneously, maternal pancreas and spleen and the placenta displayed marked overgrowth; and the maternal ceca microbiome showed alterations in relative abundance of several bacterial subpopulations. Moreover, litters born from maternal hepatic Ascl1-deficient dams experienced abnormal postnatal growth after weaning, implying an adverse pregnancy outcome. Mechanistically, we found that maternal hepatocytes deficient for Ascl1 exhibited robust activation of insulin-like growth factor 2 expression, which may contribute to the Ascl1-dependent phenotypes widespread in maternal and uteroplacental compartments.In summary, we demonstrate that maternal liver, via activating Ascl1 expression, modulates the adaptations of maternal organs and the growth of the placenta to maintain a healthy pregnancy. Our studies reveal Ascl1 as a novel and critical regulator of the physiology of pregnancy.
Loss of Sprouty produces a ciliopathic skeletal phenotype in mice through upregulation of Hedgehog signaling
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
Hruba, E;Kavkova, M;Dalecka, L;Macholan, M;Zikmund, T;Varecha, M;Bosakova, M;Kaiser, J;Krejci, P;Hovorakova, M;Buchtova, M;
PMID: 34423857 | DOI: 10.1002/jbmr.4427
The Sprouty family is a highly conserved group of intracellular modulators of receptor tyrosine kinase (RTK)-signaling pathways, which have been recently linked to primary cilia. Disruptions in the structure and function of primary cilia cause inherited disorders called ciliopathies. We aimed to evaluate Sprouty2 and Sprouty4 gene dependent alterations of ciliary structure and to focus on the determination of its association with Hedgehog signaling defects in chondrocytes. Analysis of the transgenic mice phenotype with Sprouty2 and Sprouty4 deficiency revealed several defects, including improper endochondral bone formation and digit patterning, or craniofacial and dental abnormalities. Moreover, reduced bone thickness and trabecular bone mass, skull deformities, or chondroma-like lesions were revealed. All these pathologies might be attributed to ciliopathies. Elongation of the ciliary axonemes in embryonic and postnatal growth plate chondrocytes was observed in Sprouty2-/- and Sprouty2+/- ;Sprouty4-/- mutants compared with corresponding littermate controls. Also, cilia-dependent Hedgehog signaling was upregulated in Sprouty2/4 mutant animals. Ptch1 and Ihh expression were upregulated in the autopodium and the proximal tibia of Sprouty2-/- ;Sprouty4-/- mutants. Increased levels of the GLI3 repressor (GLI3R) form were detected in Sprouty2/4 mutant primary fibroblast embryonic cell cultures and tissues. These findings demonstrate that mouse lines deficient in Sprouty proteins manifest phenotypic features resembling ciliopathic phenotypes in multiple aspects and may serve as valuable models to study the association between overactivation of RTK and dysfunction of primary cilia during skeletogenesis. This article is protected by
TNF-Related Apoptosis-Inducing Ligand (TRAIL) Loss in Canine Mammary Carcinoma
Veterinary and comparative oncology
Kim, SH;Seung, BJ;Bae, MK;Lim, HY;Cho, SH;Sur, JH;
PMID: 34423555 | DOI: 10.1111/vco.12767
Escaping apoptosis is a hallmark of cancer. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a central molecule that regulates the extrinsic apoptotic pathway, has been widely investigated in human oncology; however, investigations focusing on the endogenous expression of TRAIL in canine tumors are lacking. Therefore, we aimed to examine the expression of endogenous TRAIL in canine mammary tumors and analyzed its correlation to downstream molecules Fas-associated death domain protein (FADD) and caspase-3, and to the apoptotic index. A total of 147 samples, classified as normal mammary gland (n = 9), mammary adenoma (n = 30), low-grade carcinoma (n = 42), and high-grade carcinoma (n = 66) were included in the immunohistochemical analyses, and 43 samples with sufficient levels of RNA were analyzed via RNA in situ hybridization and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. In immunohistochemistry, TRAIL protein expression was significantly decreased in high-grade carcinoma compared to those in normal mammary gland and adenoma, with similar downregulation of TRAIL mRNA expression. Also, FADD and caspase-3 expression positively correlated with TRAIL expression. However, the apoptotic index was paradoxically elevated in high-grade tumors. Overall, these results suggest that loss of TRAIL accompanied by dysregulation of TRAIL-induced extrinsic apoptotic pathway molecules could affect malignant progression of canine mammary tumors.This article is protected by
The rostromedial tegmental (RMTg) \"brake\" on dopamine and behavior: A decade of progress but also much unfinished work
Jhou, T;
PMID: 34433088 | DOI: 10.1016/j.neuropharm.2021.108763
Between 2005-2009, several research groups identified a strikingly dense inhibitory input to midbrain dopamine neurons in a previously uncharted region posterior to the ventral tegmental area (VTA). This region is now denoted as either the rostromedial tegmental nucleus (RMTg) or the "tail of the VTA" (tVTA), and is recognized to express distinct genetic markers, encode negative "prediction errors" (inverse to dopamine neurons), and play critical roles in behavioral inhibition and punishment learning. RMTg neurons are also influenced by many categories of abused drugs, and may drive some aversive responses to such drugs, particularly cocaine and alcohol. However, despite much progress, many important questions remain about RMTg molecular/genetic properties, diversity of projection targets, and applications to addiction, depression, and other neuropsychiatric disorders.
Retinal Ganglion Cell Axon Regeneration Requires Complement and Myeloid Cell Activity within the Optic Nerve
The Journal of neuroscience : the official journal of the Society for Neuroscience
Peterson, SL;Li, Y;Sun, CJ;Wong, KA;Leung, KS;de Lima, S;Hanovice, NJ;Yuki, K;Stevens, B;Benowitz, LI;
PMID: 34417332 | DOI: 10.1523/JNEUROSCI.0555-21.2021
Axon regenerative failure in the mature CNS contributes to functional deficits following many traumatic injuries, ischemic injuries and neurodegenerative diseases. The complement cascade of the innate immune system responds to pathogen threat through inflammatory cell activation, pathogen opsonization, and pathogen lysis, and complement is also involved in CNS development, neuroplasticity, injury, and disease. Here, we investigated the involvement of the classical complement cascade and microglia/monocytes in CNS repair using the mouse optic nerve injury (ONI) model, in which axons arising from retinal ganglion cells (RGCs) are disrupted. We report that central complement C3 protein and mRNA, classical complement C1q protein and mRNA, and microglia/monocyte phagocytic complement receptor CR3 all increase in response to ONI, especially within the optic nerve itself. Importantly, genetic deletion of C1q, C3, or CR3 attenuates RGC axon regeneration induced by several distinct methods, with minimal effects on RGC survival. Local injections of C1q function-blocking antibody revealed that complement acts primarily within the optic nerve, not retina, to support regeneration. Moreover, C1q opsonizes and CR3+ microglia/monocytes phagocytose growth-inhibitory myelin debris after optic nerve injury, a likely mechanism through which complement and myeloid cells support axon regeneration. Collectively, these results indicate that local optic nerve complement-myeloid phagocytic signaling is required for CNS axon regrowth, emphasizing the axonal compartment and highlighting a beneficial neuro-immune role for complement and microglia/monocytes in CNS repair.SIGNIFICANCE STATEMENTDespite the importance of achieving axon regeneration after CNS injury and the inevitability of inflammation after such injury, the contributions of complement and microglia to CNS axon regeneration are largely unknown. Whereas inflammation is commonly thought to exacerbate the effects of CNS injury, we find that complement proteins C1q and C3 and microglia/monocyte phagocytic complement receptor CR3 are each required for retinal ganglion cell axon regeneration through the injured mouse optic nerve. Also, whereas studies of optic nerve regeneration generally focus on the retina, we show that the regeneration-relevant role of complement and microglia/monocytes likely involves myelin phagocytosis within the optic nerve. Thus, our results point to the importance of the innate immune response for CNS repair.
Neuroinflammatory astrocyte subtypes in the mouse brain
Hasel, P;Rose, IVL;Sadick, JS;Kim, RD;Liddelow, SA;
PMID: 34413515 | DOI: 10.1038/s41593-021-00905-6
Astrocytes undergo an inflammatory transition after infections, acute injuries and chronic neurodegenerative diseases. How this transition is affected by time and sex, its heterogeneity at the single-cell level and how sub-states are spatially distributed in the brain remains unclear. In this study, we investigated transcriptome changes of mouse cortical astrocytes after an acute inflammatory stimulus using the bacterial cell wall endotoxin lipopolysaccharide. We identified fast transcriptomic changes in astrocytes occurring within hours that drastically change over time. By sequencing ~80,000 astrocytes at single-cell resolution, we show that inflammation causes a widespread response with subtypes of astrocytes undergoing distinct inflammatory transitions with defined transcriptomic profiles. We also attribute key sub-states of inflammation-induced reactive astrocytes to specific brain regions using spatial transcriptomics and in situ hybridization. Together, our datasets provide a powerful resource for profiling astrocyte heterogeneity and will be useful for understanding the biological importance of regionally constrained reactive astrocyte sub-states.
A human forebrain organoid model of fragile X syndrome exhibits altered neurogenesis and highlights new treatment strategies
Kang, Y;Zhou, Y;Li, Y;Han, Y;Xu, J;Niu, W;Li, Z;Liu, S;Feng, H;Huang, W;Duan, R;Xu, T;Raj, N;Zhang, F;Dou, J;Xu, C;Wu, H;Bassell, GJ;Warren, ST;Allen, EG;Jin, P;Wen, Z;
PMID: 34413513 | DOI: 10.1038/s41593-021-00913-6
Fragile X syndrome (FXS) is caused by the loss of fragile X mental retardation protein (FMRP), an RNA-binding protein that can regulate the translation of specific mRNAs. In this study, we developed an FXS human forebrain organoid model and observed that the loss of FMRP led to dysregulated neurogenesis, neuronal maturation and neuronal excitability. Bulk and single-cell gene expression analyses of FXS forebrain organoids revealed that the loss of FMRP altered gene expression in a cell-type-specific manner. The developmental deficits in FXS forebrain organoids could be rescued by inhibiting the phosphoinositide 3-kinase pathway but not the metabotropic glutamate pathway disrupted in the FXS mouse model. We identified a large number of human-specific mRNAs bound by FMRP. One of these human-specific FMRP targets, CHD2, contributed to the altered gene expression in FXS organoids. Collectively, our study revealed molecular, cellular and electrophysiological abnormalities associated with the loss of FMRP during human brain development.
Microglial transcriptome analysis in the rNLS8 mouse model of TDP-43 proteinopathy reveals discrete expression profiles associated with neurodegenerative progression and recovery
Acta neuropathologica communications
Hunter, M;Spiller, KJ;Dominique, MA;Xu, H;Hunter, FW;Fang, TC;Canter, RG;Roberts, CJ;Ransohoff, RM;Trojanowski, JQ;Lee, VM;
PMID: 34412701 | DOI: 10.1186/s40478-021-01239-x
The microglial reaction is a hallmark of neurodegenerative conditions, and elements thereof may exert differential effects on disease progression, either worsening or ameliorating severity. In amyotrophic lateral sclerosis (ALS), a syndrome characterized by cytoplasmic aggregation of TDP-43 protein and atrophy of motor neurons in the cortex and spinal cord, the transcriptomic signatures of microglia during disease progression are incompletely understood. Here, we performed longitudinal RNAseq analysis of cortical and spinal cord microglia from rNLS8 mice, in which doxycycline-regulatable expression of human TDP-43 (hTDP-43) in the cytoplasm of neurons recapitulates many features of ALS. Transgene suppression in rNLS8 mice leads to functional, anatomical and electrophysiological resolution that is dependent on a microglial reaction that is concurrent with recovery rather than disease onset. We identified basal differences between the gene expression profiles of microglia dependent on localization in spinal cord or cortex. Microglia subjected to chronic hTDP-43 overexpression demonstrated transcriptomic changes in both locations. We noted strong upregulation of Apoe, Axl, Cd63, Clec7a, Csf1, Cst7, Igf1, Itgax, Lgals3, Lilrb4, Lpl and Spp1 during late disease and recovery. Importantly, we identified a distinct suite of differentially expressed genes associated with each phase of disease progression and recovery. Differentially expressed genes were associated with chemotaxis, phagocytosis, inflammation, and production of neuroprotective factors. These data provide new insights into the microglial reaction in TDP-43 proteinopathy. Genes differentially expressed during progression and recovery may provide insight into a unique instance in which the microglial reaction promotes functional recovery after neuronal insult.
Mucosal and faecal neutrophil gelatinase-associated lipocalin as potential biomarkers for collagenous colitis
Journal of gastroenterology
Bakke, I;Walaas, GA;Bruland, T;Røyset, ES;van Beelen Granlund, A;Escudero-Hernández, C;Thorsvik, S;Münch, A;Sandvik, AK;Østvik, AE;
PMID: 34414506 | DOI: 10.1007/s00535-021-01814-y
Collagenous colitis (CC) is an inflammatory bowel disease where chronic diarrhoea is the main symptom. Diagnostic markers distinguishing between CC and other causes of chronic diarrhoea remain elusive. This study explores neutrophil gelatinase-associated lipocalin (NGAL) and its mRNA lipocalin2 (LCN2) as histological and faecal disease markers in CC.NGAL/LCN2 were studied in colonic biopsies from CC patients before and during budesonide treatment using RNA sequencing (n = 9/group), in situ hybridization (ISH) (n = 13-22/group) and immunohistochemistry (IHC) (n = 14-25/group). Faecal samples from CC (n = 3-28/group), irritable bowel syndrome diarrhoea (IBS-D) (n = 14) and healthy controls (HC) (n = 15) were assayed for NGAL and calprotectin.NGAL/LCN2 protein and mRNA expression were upregulated in active CC vs HC, and vs paired samples of treated CC in clinical remission. IHC and ISH localized increased NGAL/LCN2 mainly to epithelium of active CC, compared to almost absence in HC and treated CC. In contrast, calprotectin was solely expressed in immune cells. Despite great individual differences, faecal NGAL was significantly increased in active CC compared to HC, IBS-D and treated CC and had high test sensitivity. Faecal calprotectin levels were variably increased in active CC, but the values remained below usual clinical cut-offs.NGAL/LCN2 is upregulated in the epithelium of active CC and reduced during budesonide-induced clinical remission to the level of HC and IBD-S. This was reflected in NGAL faecal concentrations. We propose NGAL as an IHC marker for disease activity in CC and a potential faecal biomarker discriminating CC from HC and IBS-D.