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

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

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

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

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

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.

Abstract MP45: Deletion Of The Transient Receptor Vanilloid-1 (TRPV1) Channel In Rats Attenuates 2 Kidney 1 Clip Hypertension

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Sean D Stocker ◽  
Leon J DeLalio
Keyword(s):  
Heart Rate ◽  
Renovascular Hypertension ◽  
Sensory Nerve ◽  
Experimental Models ◽  
Sensory Nerves ◽  
Male Rats ◽  
Wild Type ◽  
Renal Nerve ◽  
Trpv1 Channels ◽  
Arterial Blood

Renal denervation lowers arterial blood pressure (ABP) in both clinical populations and multiple experimental models of hypertension. This therapeutic effect is partly attributed to the removal of overactive renal sensory nerves that increase sympathetic efferent activity and ABP. Renal sensory nerves highly express TRPV1 channels, and administration of the TRPV1 agonist capsaicin increases renal sensory nerve activity. However, the extent by which TRPV1 channels directly contribute to renal nerve dependent models of hypertension has not been tested. To test this hypothesis, we generated a novel TRPV1 -/- rat using CRISPR/Cas9 and deletion of exon 3. Male and female TRPV1 -/- and wild-type littermates (8-12 weeks) were instrumented with telemetry. At 2 weeks later, renovascular hypertension via renal stenosis was produced by placement of a PTFE cuff (0.16 x 0.22 inches, 1mm long) around the right renal artery. Male TRPV1 -/- and wild-type rats had no differences in baseline mean ABP (99±2 vs 98±3 mmHg, respectively; n=7-9) or heart rate (390±7 vs 400±8 bpm, respectively). Renal stenosis significantly increased mean ABP in both groups; however, mean ABP was significantly lower at Day 28 in male TRPV1 -/- versus wild-type rats (125±8 vs 155±2 mmHg, respectively: P<0.01). Ganglionic blockade with chlorisondamine (2.5mg/kg, sc) at Day 28 produced a smaller fall in mean ABP of male TRPV1 -/- versus wild-type rats (-53±4 vs -86±3 mmHg, respectively; P<0.001). On the other hand, female TRPV1 -/- and wild-type rats had no differences in baseline mean ABP (102±2 vs 104±1 mmHg, respectively; n=6-9) or heart rate (419±8 vs 410±7 bpm, respectively). Renal stenosis significantly increased mean ABP in both groups; however, there were no differences at Day 28 between female TRPV1 -/- versus wild-type rats (117±8 vs 122±6 mmHg, respectively). Moreover, the increase in mean ABP was smaller in females versus males. The ganglionic blocker chlorisondamine produced similar depressor responses in female TRPV1 -/- versus wild-type rats (-64±7 vs -65±7 mmHg, respectively). These findings illustrate a sex difference in renovascular hypertension in rats, but importantly indicate that TRPV1 channels contribute to the established phase of renovascular hypertension in male rats.

Hymenolepis diminuta: metacestode-induced reduction in the synthesis of the yolk protein, vitellogenin, in the fat body of Tenebrio molitor

Parasitology ◽  
1996 ◽  
Vol 112 (4) ◽  
pp. 429-436 ◽  
Author(s):  
T. J. Webb ◽  
H. Hurd
Keyword(s):  
Post Infection ◽  
Fat Body ◽  
Potent Inhibitor ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Vitellogenin Synthesis ◽  
Specific Stage ◽  
Fat Bodies ◽  
Do So

SUMMARYVitellogenin synthesis by the fat body has been monitored using in vitro culture and immunoprecipitation. This system was found to be efficient for measuring vitellogenin production in both non-infected Tenebrio molitor and those infected with Hymenolepis diminuta. In fat bodies from infected beetles, vitellogenin production was decreased by up to 75% (day 24 post-infection) and, at all times investigated, vitellogenin synthesis was significantly below control levels (days 3–30 post-infection). Incubating fat bodies from control insects with isolated metacestodes indicated that this may be a direct effect by the parasite which is developmental stage-specific. Stage II, but not stage III–IV, nor heat-killed parasites could bring about this decrease in vitellogenin. In addition, these effects may be density dependent within the range of 2–20 parasites per fat body; only 2 metacestodes were necessary to cause a significant decrease. Since metacestodes do not take up vitellogenin, nor limit the amount of [14C] leucine available to the fat body for vitellogenin production, it is conceivable that the parasite produces a potent inhibitor of vitellogenin synthesis, or a molecule which induces cells within the fat body to do so.

scholarly journals IgA dysfunction induced by the early-lifetime disruption of gut microbiota aggravates diet–induced metabolic syndrome in mice

2021 ◽  
Author(s):  
Jielong Guo ◽  
Xue Han ◽  
Yilin You ◽  
Weidong Huang ◽  
Zhan Jicheng
Keyword(s):  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Early Life ◽  
Low Dose ◽  
Dependent Manner ◽  
Wild Type ◽  
Bacterial Composition ◽  
Germ Free ◽  
Iga Response ◽  
Intestinal Iga

Abstract BackgroundLow-dose antibiotic contamination in animal food is still a severe food safety problem worldwide. Penicillin is one of the main classes of antibiotics being detected in food. Previous studies have shown that transient exposure of low-dose penicillin (LDP) during early life resulted in metabolic syndrome (MetS) in mice. However, the underlying mechanism(s) and efficient approaches to counteracting this are largely unknown.MethodsWild-type (WT) or secretory IgA (SIgA)-deficient (Pigr-/-) C57BL/6 mice were exposed to LDP or not from several days before birth to 30 d of age. Five times of FMT or probiotics (a mixture of Lactobacillus bulgaricus and L. rhamnosus GG) treatments were applied to parts of these LDP-treated mice from 12 d to 28 d of life. Bacterial composition from different regions (mucosa and lumen) of the colon and ileum were analyzed through 16S rDNA sequencing. Intestinal IgA response was analyzed. Multiple parameters related to MetS were also determined. In addition, germ-free animals and in vitro tissue culture were also used to determine the correlations between LDP, gut microbiota (GM) and intestinal IgA response.ResultsLDP disturbed the intestinal bacterial composition, especially for ileal mucosa, the main inductive and effective sites of IgA response, in 30-d-old mice. The alteration of early GM resulted in a persistent inhibition of the intestinal IgA response, leading to a constant reduction of fecal and caecal SIgA levels throughout the 25-week experiment, which is early life-dependent, as transfer of LDP-GM to 30 d germ-free mice only resulted in a transient reduction in fecal SIgA. LDP-induced reduction in SIgA led to a decrease in IgA+ bacteria and a dysbiosis in the ileal mucosal samples of 25 week wild-type but not Pigr-/- mice. Moreover, LDP also resulted in increases in ileal bacterial encroachment and adipose inflammation, along with an enhancement of diet-induced MetS in an intestinal SIgA-dependent manner. Furthermore, several times of FMT or probiotic treatments during LDP treatment are efficient to fully (for FMT) or partially (for probiotics) counteract the LDP-effect on both GM and metabolism.ConclusionsEarly-life LDP-induced enhancement of diet-induced MetS is mediated by intestinal SIgA, which could be (partially) restored by FMT or probiotics treatment.

scholarly journals BATF acts as an essential regulator of IL-25–responsive migratory ILC2 cell fate and function

2020 ◽  
Vol 5 (43) ◽  
pp. eaay3994 ◽  
Author(s):  
Mindy M. Miller ◽  
Preeyam S. Patel ◽  
Katherine Bao ◽  
Thomas Danhorn ◽  
Brian P. O’Connor ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Leucine Zipper ◽  
Mucosal Barrier ◽  
Nippostrongylus Brasiliensis ◽  
Cell Hyperplasia ◽  
Basic Leucine Zipper ◽  
Tuft Cell ◽  
Group 2 ◽  
And Function

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.

scholarly journals ILC2s mediate systemic innate protection by priming mucus production at distal mucosal sites

2019 ◽  
Vol 216 (12) ◽  
pp. 2714-2723 ◽  
Author(s):  
Laura Campbell ◽  
Matthew R. Hepworth ◽  
Jayde Whittingham-Dowd ◽  
Seona Thompson ◽  
Allison J. Bancroft ◽  
...  
Keyword(s):  
Goblet Cell ◽  
Helminth Infection ◽  
Host Immunity ◽  
Mucosal Barrier ◽  
Parasitic Nematodes ◽  
Cell Hyperplasia ◽  
Mucus Production ◽  
Mucin Production ◽  
Helminth Infections

Host immunity to parasitic nematodes requires the generation of a robust type 2 cytokine response, characterized by the production of interleukin 13 (IL-13), which drives expulsion. Here, we show that infection with helminths in the intestine also induces an ILC2-driven, IL-13–dependent goblet cell hyperplasia and increased production of mucins (Muc5b and Muc5ac) at distal sites, including the lungs and other mucosal barrier sites. Critically, we show that type 2 priming of lung tissue through increased mucin production inhibits the progression of a subsequent lung migratory helminth infection and limits its transit through the airways. These data show that infection by gastrointestinal-dwelling helminths induces a systemic innate mucin response that primes peripheral barrier sites for protection against subsequent secondary helminth infections. These data suggest that innate-driven priming of mucus barriers may have evolved to protect from subsequent infections with multiple helminth species, which occur naturally in endemic areas.

scholarly journals Angptl4 does not control hyperglucagonemia or α-cell hyperplasia following glucagon receptor inhibition

2017 ◽  
Vol 114 (10) ◽  
pp. 2747-2752 ◽  
Author(s):  
Haruka Okamoto ◽  
Katie Cavino ◽  
Erqian Na ◽  
Elizabeth Krumm ◽  
Steven Kim ◽  
...  
Keyword(s):  
Cell Mass ◽  
Plasma Triglyceride ◽  
Plasma Glucagon ◽  
Wild Type ◽  
Cell Hyperplasia ◽  
Glucagon Receptor ◽  
Blocking Antibody ◽  
Receptor Inhibition ◽  
Amino Acid Levels ◽  
Pharmacologic Inhibition

Genetic disruption or pharmacologic inhibition of glucagon signaling effectively lowers blood glucose but results in compensatory glucagon hypersecretion involving expansion of pancreatic α-cell mass. Ben-Zvi et al. recently reported that angiopoietin-like protein 4 (Angptl4) links glucagon receptor inhibition to hyperglucagonemia and α-cell proliferation [Ben-Zvi et al. (2015)Proc Natl Acad Sci USA112:15498–15503]. Angptl4 is a secreted protein and inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. We report thatAngptl4−/−mice treated with an anti-glucagon receptor monoclonal antibody undergo elevation of plasma glucagon levels and α-cell expansion similar to wild-type mice. Overexpression of Angptl4 in liver of mice caused a 8.6-fold elevation in plasma triglyceride levels, but did not alter plasma glucagon levels or α-cell mass. Furthermore, administration of glucagon receptor-blocking antibody to healthy individuals increased plasma glucagon and amino acid levels, but did not change circulating Angptl4 concentration. These data show that Angptl4 does not link glucagon receptor inhibition to compensatory hyperglucagonemia or expansion of α-cell mass, and that it cannot be given to induce such secretion and growth. The reduction of plasma triglyceride levels inAngptl4−/−mice and increase following Angptl4 overexpression suggest that changes in plasma triglyceride metabolism do not regulate α-cells in the pancreas. Our findings corroborate recent data showing that increased plasma amino acids and their transport into α-cells link glucagon receptor blockage to α-cell hyperplasia.

scholarly journals Early postnatal exposure of mice to side-steam tobacco smoke increases neuropeptide Y in lung

2012 ◽  
Vol 302 (1) ◽  
pp. L152-L159 ◽  
Author(s):  
Z.-X. Wu ◽  
K. B. Benders ◽  
D. D. Hunter ◽  
R. D. Dey
Keyword(s):  
Smooth Muscle ◽  
Neuropeptide Y ◽  
Tobacco Smoke ◽  
Early Life ◽  
Nerve Fibers ◽  
Sensory Nerves ◽  
Sensory Innervation ◽  
Tracheal Smooth Muscle ◽  
Exposure Group ◽  
Postnatal Exposure

Our recent study showed that prenatal and early postnatal exposure of mice to side-steam tobacco smoke (SS), a surrogate to environmental tobacco smoke (ETS), leads to increased airway responsiveness and sensory innervation later in life. However, the underlying mechanism initiated in early life that affects airway responses later in life remains undefined. The concomitant increase in nerve growth factor (NGF) after exposures suggests that NGF may be involved the regulation of airway innervation. Since NGF regulates sympathetic nerve responses, as well as sensory nerves, we extended previous studies by examining neuropeptide Y (NPY), a neuropeptide associated with sympathetic nerves. Different age groups of mice, postnatal day (PD) 2 and PD21, were exposed to either SS or filtered air (FA) for 10 consecutive days. The level of NPY protein in lung and the density of NPY nerve fibers in tracheal smooth muscle were significantly increased in the PD2–11SS exposure group compared with PD2–11FA exposure. At the same time, the level of NGF in lung tissue was significantly elevated in the PD2–11SS exposure groups. However, neither NPY (protein or nerves) nor NGF levels were significantly altered in PD21–30SS exposure group compared with the PD21–30FA exposure group. Furthermore, pretreatment with NGF antibody or K252a, which inhibits a key enzyme (tyrosine kinase) in the transduction pathway for NGF receptor binding, significantly diminished SS-enhanced NPY tracheal smooth muscle innervation and the increase in methacholine-induced airway resistance. These findings show that SS exposure in early life increases NPY tracheal innervation and alters pulmonary function and that these changes are mediated through the NGF.

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