Succinate‐Induced Tuft Cell Hyperplasia Enhances FFA2/5‐HT Mediated Anion Secretion in Mouse Duodenum

A transitory, interleukin-25 (IL-25)–responsive, group 2 innate lymphoid cell (ILC2) subset induced during type 2 inflammation was recently identified as iILC2s. This study focuses on understanding the significance of this population in relation to tissue-resident nILC2s in the lung and intestine. RNA-sequencing and pathway analysis revealed the AP-1 superfamily transcription factor BATF (basic leucine zipper transcription factor, activating transcription factor–like) as a potential modulator of ILC2 cell fate. Infection of BATF-deficient mice with Nippostrongylus brasiliensis showed a selective defect in IL-25–mediated helminth clearance and a corresponding loss of iILC2s in the lung characterized as IL-17RBhigh, KLRG1high, BATFhigh, and Arg1low. BATF deficiency selectively impaired iILC2s because it had no impact on tissue-resident nILC2 frequency or function. Pulmonary-associated iILC2s migrated to the lung after infection, where they represented an early source of IL-4 and IL-13. Although the composition of ILC2s in the small intestine was distinct from those in the lung, their frequency and IL-13 expression remained dependent on BATF, which was also required for optimal goblet and tuft cell hyperplasia. Findings support IL-25–responsive ILC2s as early sentinels of mucosal barrier integrity.

Download Full-text

Commensal-derived succinate enhances tuft cell specification and suppresses ileal inflammation

10.1101/776724 ◽

2019 ◽

Author(s):

Amrita Banerjee ◽

Charles A. Herring ◽

Hyeyon Kim ◽

Bob Chen ◽

Alan J. Simmons ◽

...

Keyword(s):

Intestinal Inflammation ◽

Genetic Model ◽

Cell Lineage ◽

Inverse Correlation ◽

Tca Cycle ◽

Cell Hyperplasia ◽

Cell Specification ◽

Tuft Cell ◽

Chronic Intestinal Inflammation

Longitudinal analysis of Crohn's disease (CD) incidence has identified an inverse correlation with helminth infestation and recent studies have revealed that intestinal tuft cell hyperplasia is critical for helminth response. Tuft cell frequency was decreased in the inflamed ilea of CD patients and a mouse model of TNFα-induced Crohn's-like ileitis (TNFΔARE). Single-cell RNA sequencing paired with unbiased differential trajectory analysis of the tuft cell lineage in a genetic model of tuft cell hyperplasia (AtohKO) demonstrated that the tuft cell lineage had increased tricarboxylic acid (TCA) cycle gene signatures. Commensal microbiome-derived succinate was detected in the ileal lumen of these animals while microbiome depletion suppressed tuft cell hyperplasia. Therapeutic succinate treatment in TNFΔARE animals reduced pathology in correlation with induced tuft cell specification. We provide evidence implicating the modulatory role of intestinal tuft cells in chronic intestinal inflammation, which could facilitate leveraging this rare and elusive cell type for CD treatment.

Download Full-text

Activation of intestinal tuft cell-expressed Sucnr1 triggers type 2 immunity in the mouse small intestine

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1720758115 ◽

2018 ◽

Vol 115 (21) ◽

pp. 5552-5557 ◽

Cited By ~ 61

Author(s):

Weiwei Lei ◽

Wenwen Ren ◽

Makoto Ohmoto ◽

Joseph F. Urban ◽

Ichiro Matsumoto ◽

...

Keyword(s):

Goblet Cell ◽

Mucosal Immunity ◽

Cell Activation ◽

Nippostrongylus Brasiliensis ◽

Infectious Agents ◽

Cell Hyperplasia ◽

Type 2 Immunity ◽

Tuft Cell ◽

Tuft Cells

The hallmark features of type 2 mucosal immunity include intestinal tuft and goblet cell expansion initiated by tuft cell activation. How infectious agents that induce type 2 mucosal immunity are detected by tuft cells is unknown. Published microarray analysis suggested that succinate receptor 1 (Sucnr1) is specifically expressed in tuft cells. Thus, we hypothesized that the succinate–Sucnr1 axis may be utilized by tuft cells to detect certain infectious agents. Here we confirmed that Sucnr1 is specifically expressed in intestinal tuft cells but not in other types of intestinal epithelial cells, and demonstrated that dietary succinate induces tuft and goblet cell hyperplasia via Sucnr1 and the tuft cell-expressed chemosensory signaling elements gustducin and Trpm5. Conventional mice with a genetic Sucnr1 deficiency (Sucnr1−/−) showed diminished immune responses to treatment with polyethylene glycol and streptomycin, which are known to enhance microbiota-derived succinate, but responded normally to inoculation with the parasitic worm Nippostrongylus brasiliensis that also produces succinate. Thus, Sucnr1 is required for microbiota-induced but not for a generalized worm-induced type 2 immunity.

Download Full-text

A47 ENTERIC TUFT CELL HYPERPLASIA FOLLOWING INFECTION WITH THE TAPEWORM HYMENOLEPIS DIMINUTA IS AFFECTED BY NEURONAL BUT NOT BACTERIAL FACTORS

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwz047.046 ◽

2020 ◽

Vol 3 (Supplement_1) ◽

pp. 55-56

Author(s):

S Rajeev ◽

M Defaye ◽

A J Shute ◽

A Wang ◽

S J Wang ◽

...

Keyword(s):

Post Infection ◽

Nerve Fibers ◽

Hymenolepis Diminuta ◽

Sensory Nerves ◽

Parasitic Nematodes ◽

Wild Type ◽

Cell Hyperplasia ◽

Germ Free ◽

Tuft Cell ◽

Rag 1

Abstract Background Tuft cells are a rare chemosensory population of the intestinal epithelium that detect intestinal parasitic nematodes and release IL-25 to mobilize innate lymphoid type 2 cells (ILC2), which then drive a Th2- dominant nematode expulsion response. Immunocompetent mice develop tuft cell hyperplasia in the small intestine during infection with Hymenolepis diminuta, a non-abrasive lumen dwelling small intestinal cestode parasite. Helminth infections are accompanied by alterations in sensory motor functions of the gut as well as the composition of the microbiota. It is poorly understood if tuft cell hyperplasia is regulated by these immunomodulatory influences. Aims To test if mice lacking (1) a functional adaptive immune system, (2) TRPV1+ gut-innervating sensory nerves and (3) a microbiome, display enteric tuft cell hyperplasia following infection with H. diminuta. Methods RAG-1-/- (male and female) and germ-free mice (n=3–6) were infected with 5 cysticercoids of H. diminuta and age matched non-infected mice served as control groups. Male C57BL/6j mice were treated with resiniferatoxin (RTX) to ablate TRPV1 +sensory neurons before infection. Mid-jejunum cryostat or paraffin embedded sections immunostained against doublecortin-like kinase -1 (DCLK-1) were blindly scored for tuft cell enumeration at 5–14 days post-infection. Results Tuft cell hyperplasia (~10-15-fold increase) was observed in the jejunum of wild-type mice at 11 days post infection with H. diminuta, by which time worms are expelled. Infected RAG-1-/- mice develop tuft cell hyperplasia of lesser magnitude than wild-type mice. Germ-free mice displayed tuft cell hyperplasia and kinetics of worm expulsion that were not different from wild-type mice. RTX-treated mice with confirmed loss of TRPV1+ nerve fibers in the gut and their cell soma in the dorsal root and nodose ganglia, had a greater increase (~2-fold) in tuft cell numbers compared to H. diminuta-only mice at 11 days post-infection. Conclusions Knowledge of how the host senses helminths in the gut lumen is central to the host-parasite interaction. Using the H. diminuta-mouse model system we find that tuft cell hyperplasia is largely, but not entirely dependent on adaptive immunity, occurs independent of the gut microbiota, and, intriguingly, TRPV1+ sensory nerves appear to act as a brake on the system, limiting the magnitude of the hyperplasia. Funding Agencies CIHRNSERC, Henry Koopman’s Memorial scholarship

Download Full-text

Factors Regulating Murine Tuft cell Hyperplasia in the Small Intestine during Infection with Hymenolepis Diminuta

The FASEB Journal ◽

10.1096/fasebj.2020.34.s1.03739 ◽

2020 ◽

Vol 34 (S1) ◽

pp. 1-1

Author(s):

Sruthi Rajeev ◽

Manon Defaye ◽

Adam Shute ◽

Arthur Wang ◽

Susan Wang ◽

...

Keyword(s):

Small Intestine ◽

Hymenolepis Diminuta ◽

Cell Hyperplasia ◽

Tuft Cell

Download Full-text

Developmental pathways regulate cytokine-driven effector and feedback responses in the intestinal epithelium

10.1101/2020.06.19.160747 ◽

2020 ◽

Cited By ~ 1

Author(s):

Håvard T. Lindholm ◽

Naveen Parmar ◽

Claire Drurey ◽

Jenny Ostrop ◽

Alberto Díez-Sanchez ◽

...

Keyword(s):

Intestinal Epithelium ◽

Goblet Cells ◽

Developmental Pathways ◽

Intestinal Epithelial ◽

Cell Hyperplasia ◽

Tuft Cell ◽

Infection Models ◽

Bmp Signalling

AbstractThe intestinal tract is a common site for infection, and it relies on an appropriate immune response to defend against pathogens. The intestinal epithelium has an important role in effector responses, which is coordinated by immune-type specific cytokines. It is incompletely understood how cytokines drive epithelial responses. Here, using organoid-cytokine co-cultures, we provide a comprehensive analysis of how key cytokines affect the intestinal epithelium, and relate this to in vivo infection models. We use imaging, based on a convolutional neural network, and transcriptomic analysis to reveal that cytokines use developmental pathways to define intestinal epithelial effector responses. For example, we find IL-22 and IL-13 dichotomously induce goblet cells, in which only IL-13 driven goblet cells are associated with NOTCH signaling. We further show that IL-13 induces BMP signalling to act as a negative feedback loop in IL-13 induced tuft cell hyperplasia, an important aspect of type 2 immunity. Together, we show that targeting developmental pathways may be a useful tool to tailor epithelial effector responses that are necessary for immunity to infection.

Download Full-text

Sox4 drives Atoh1-independent intestinal secretory differentiation toward tuft and enteroendocrine fates

10.1101/183400 ◽

2017 ◽

Author(s):

Adam D Gracz ◽

Leigh Ann Samsa ◽

Matthew J Fordham ◽

Danny C Trotier ◽

Bailey Zwarycz ◽

...

Keyword(s):

Single Cell ◽

Parasitic Infection ◽

Rna Seq ◽

Wild Type ◽

Cell Hyperplasia ◽

Tuft Cell ◽

Tuft Cells ◽

Secretory Differentiation

Background & AimsThe intestinal epithelium is maintained by intestinal stem cells (ISCs), which produce post-mitotic absorptive and secretory epithelial cells. Initial fate specification toward enteroendocrine, goblet, and Paneth cell lineages is dependent on Atoh1, a master regulator of secretory differentiation. However, the origin of tuft cells, which participate in Type II immune responses to parasitic infection, is less clear and appears to occur in an Atoh1-independent manner. Here we examine the role of Sox4 in ISC proliferation and differentiation.MethodsWe used mice with intestinal epithelial-specific conditional knockout of Sox4 (Sox4fl/fl:vilCre; Sox4cKO) to study the role of Sox4 in the small intestine. Crypt- and single cell-derived organoids were used to assay proliferation and ISC potency between control and Sox4cKO mice. Lineage allocation and genetic consequences of Sox4 ablation were studied by immunofluorescence, RT-qPCR, and RNA-seq. In vivo infection with helminths and in vitro cytokine treatment in primary intestinal organoids were used to assess tuft cell hyperplasia in control and Sox4cKO samples. Atoh1GFP reporter mice and single cell RNA-seq (scRNA-seq) were used to determine co-localization of SOX4 and Atoh1. Wild-type and inducible Atoh1 knockout (Atoh1fl/fl:vilCreER; Atoh1iKO) organoids carrying an inducible Sox4 overexpression vector (Sox4OE) were used to determine the role of Atoh1 in Sox4 driven secretory differentiation.ResultsLoss of Sox4 impairs ISC function and secretory differentiation, resulting in decreased numbers of enteroendocrine and tuft cells. In wild-type mice, SOX4+ cells are significantly upregulated following helminth infection coincident with tuft cell hyperplasia. Sox4 is activated by IL13 in vitro and Sox4cKO knockout mice demonstrate impaired tuft cell hyperplasia and parasite clearance following infection with helminths. A subset of Sox4-expressing cells colocalize with Atoh1 and enteroendocrine markers by scRNA-seq, while Sox4+/Atoh1-cells correlate strongly with tuft cell populations. Gain-of-function studies in primary organoids demonstrate that Sox4 is sufficient to drive both enteroendocrine and tuft cell differentiation, and can do so in the absence of Atoh1.ConclusionOur data demonstrate that Sox4 promotes enteroendocrine and tuft cell lineage allocation independently of Atoh1. These results challenge long-standing views of Atoh1 as the sole regulator of secretory differentiation in the intestine and are relevant for understanding host epithelial responses to parasitic infection.

Download Full-text

The effect of bromocriptine on mammary-gland ultrastructure of hyperprolactinemic rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111136 ◽

1984 ◽

Vol 42 ◽

pp. 204-205

Author(s):

I.C. Murray

Keyword(s):

Mammary Gland ◽

Dopamine Agonist ◽

Alveolar Epithelium ◽

Mammary Glands ◽

Female Rats ◽

Control Group ◽

Cell Hyperplasia ◽

Once Daily ◽

Long Evans

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.

Download Full-text

Adrenocortical Ultrastructure in Ectopic Acth Syndrome

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091172 ◽

1976 ◽

Vol 34 ◽

pp. 238-239

Author(s):

K. Kovacs ◽

E. Horvath ◽

W. Singer

Keyword(s):

Adrenal Cortex ◽

Zona Glomerulosa ◽

Ectopic Acth Syndrome ◽

Pituitary Neoplasms ◽

Electron Microscopic ◽

Adrenocortical Cells ◽

Cell Hyperplasia ◽

Ectopic Acth ◽

Ectopic Acth Production ◽

Microscopic Findings

Secretion of ACTH by non-pituitary neoplasms is recognized with increasing frequency. While the clinical and biochemical changes associated with ectopic ACTH production have been extensively studied recently, relatively little attention was focused on the morphology of the adrenal cortex and, to our knowledge, the fine structure of the adrenocortical cells in cases of ectopic ACTH syndrome has not been described so far. We report here the electron microscopic findings in the adrenal cortex of a 50-year-old man with a pancreatic apudoma. The patient showed the characteristic clinical and biochemical features of ectopic ACTH syndrome and because of extensive hypercorticism, underwent bilateral adrenalectomy.By light microscopy, the adrenal cortices showed extensive compact cell hyperplasia and lipid depletion. The zona glomerulosa was present in small foci and, except for a few places, fasciculata cells were noted under the fibrous capsule.

Download Full-text

Association of pituitary adenoma with neuronal christoma: A TEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016889x ◽

1994 ◽

Vol 52 ◽

pp. 232-233

Author(s):

Eva Horvath ◽

Kalman Kovacs ◽

B. W. Scheithauer ◽

R. V. Lloyd ◽

H. S. Smyth

Keyword(s):

Growth Hormone ◽

Pituitary Adenoma ◽

Pituitary Tumor ◽

Nervous Tissue ◽

Alternative Explanation ◽

Growth Hormone Releasing Hormone ◽

Cell Hyperplasia ◽

Releasing Hormone ◽

Secretory Neurons

The association of a pituitary adenoma with nervous tissue consisting of neuron-like cells and neuropil is a rare abnormality. In the majority of cases, the pituitary tumor is a chromophobic adenoma, accompanied by acromegaly. Histology reveals widely variable proportions of endocrine and nervous tissue in alternating or intermingled patterns. The lesion is perceived as a composite one consisting of two histogenetically distinct parts. It has been suggested that the neuronal component, morphologically similar to secretory neurons of the hypothalamus, may initiate adenoma formation by releasing stimulatory substances. Immunoreactivity for growth hormone releasing hormone (GRH) in the neuronal component of some cases supported this view, whereas other findings such as consistent lack of growth hormone (GH) cell hyperplasia in the lesions called for alternative explanation.Fifteen tumors consisting of a pituitary adenoma and a neuronal component have been collected over a 20 yr. period. Acromegaly was present in 11 patients, was equivocal in one, and absent in 3.

Download Full-text