Acidic chitinase primes the protective immune response to gastrointestinal nematodes.

Acidic mammalian chitinase (AMCase) is known to be induced by allergens and helminths, yet its role in immunity is unclear. Using AMCase-deficient mice, we show that AMCase deficiency reduced the number of group 2 innate lymphoid cells during allergen challenge but was not required for establishment of type 2 inflammation in the lung in response to allergens or helminths. In contrast, AMCase-deficient mice showed a profound defect in type 2 immunity following infection with the chitin-containing gastrointestinal nematodes Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. The impaired immunity was associated with reduced mucus production and decreased intestinal expression of the signature type 2 response genes Il13, Chil3, Retnlb, and Clca1. CD103(+) dendritic cells, which regulate T cell homing, were also reduced in mesenteric lymph nodes of infected AMCase-deficient mice. Thus, AMCase functions as a critical initiator of protective type 2 responses to intestinal nematodes but is largely dispensable for allergic responses in the lung.

Resistin-like molecule ß acts as a mitogenic factor in hypoxic pulmonary hypertension via the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK signaling pathways.

BACKGROUND: Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule ß (RELM-ß) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-ß has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-ß in HPH remain unclear. METHODS: We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-ß in a rat HPH model and in hPASMCs. RESULTS: Overexpression of RELM-ß caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-ß partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-ß gene overexpression or silencing, respectively. Recombinant RELM-ß protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-ß on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor. CONCLUSIONS: Our findings suggest that RELM-ß acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-ß are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.

Pathological Type-2 Immune Response, Enhanced Tumor Growth, and Glucose Intolerance in Retnlß (RELMß) Null Mice: A Model of Intestinal Immune System Dysfunction in Disease Susceptibility.

Resistin, and its closely related homologs, the resistin-like molecules (RELMs) have been implicated in metabolic dysregulation, inflammation, and cancer. Specifically, RELMß, expressed predominantly in the goblet cells in the colon, is released both apically and basolaterally, and is hence found in both the intestinal lumen in the mucosal layer as well as in the circulation. RELMß has been linked to both the pathogenesis of colon cancer and type 2 diabetes. RELMß plays a complex role in immune system regulation, and the impact of loss of function of RELMß on colon cancer and metabolic regulation has not been fully elucidated. We therefore tested whether Retnlß (mouse ortholog of human RETNLß) null mice have an enhanced or reduced susceptibility for colon cancer as well as metabolic dysfunction. We found that the lack of RELMß leads to increased colonic expression of T helper cell type-2 cytokines and IL-17, associated with a reduced ability to maintain intestinal homeostasis. This defect leads to an enhanced susceptibility to the development of inflammation, colorectal cancer, and glucose intolerance. In conclusion, the phenotype of the Retnlß null mice unravels new aspects of inflammation-mediated diseases and strengthens the notion that a proper intestinal barrier function is essential to sustain a healthy phenotype.

Comparison of RELMα and RELMß Single- and Double-Gene-Deficient Mice Reveals that RELMα Expression Dictates Inflammation and Worm Expulsion in Hookworm Infection.

Resistin-like molecules (RELMs) are highly expressed following helminth infection, where they impact both the host and helminth. While RELMα (Retnla) impairs helminth expulsion by inhibiting protective Th2 immunity, RELMß (Retnlb) can promote its expulsion. We employed Retnla(-/-) and Retnlb(-/-) mice to delineate the function of both proteins following infection with Nippostrongylus brasiliensis, a hookworm that infects the lung and intestine. Whereas wild-type (WT) and Retnlb(-/-)mice exhibited equivalent infection-induced inflammation, Retnla(-/-) mice suffered a heightened inflammatory response, including increased mortality, weight loss, and lung inflammation. In the intestine, Retnla(-/-)mice had low parasite egg burdens compared to those of WT mice, while Retnlb(-/-) mice exhibited high egg burdens, suggesting that RELMα and RELMß have functionally distinct effects on immunity and inflammation to N. brasiliensis To test the importance of both proteins, we generated Retnla(-/-) Retnlb(-/-) mice. Infected Retnla(-/-)Retnlb(-/-) mice exhibited similar responses to Retnla(-/-) mice, including increased mortality and lung inflammation. This inflammatory response in Retnla(-/-) Retnlb(-/-) mice negatively impacted N. brasiliensis fitness, as demonstrated by significantly lower worm ATP levels and decreased intestinal worm burden and fecundity. Lung cytokine analysis revealed that Retnla(-/-) and Retnla(-/-) Retnlb(-/-) mice expressed significantly increased levels of interleukin-4 (IL-4). Finally, we generated Retnla(-/-) mice on the Rag(-/-) background and observed that the effects of RELMα were abrogated in the absence of adaptive immunity. Together, these data demonstrate that RELMα but not RELMß significantly impacts the immune response toN. brasiliensis infection by downregulating the Th2 adaptive immune response in the lung, which protects the host but allows improved parasite fitness.

Critical Role for Interleukin-25 in Host Protective Th2 Memory Response against Heligmosomoides polygyrus bakeri.

Infection with parasitic nematodes, especially gastrointestinal geohelminths, affects hundreds of millions of people worldwide and thus poses a major risk to global health. The host mechanism of defense against enteric nematode infection remains to be fully understood, but it involves a polarized type 2 immunity leading to alterations in intestinal function that facilitate worm expulsion. We investigated the role of interleukin-25 (IL-25) in host protection against Heligmosomoides polygyrus bakeri infection in mice. Our results showed that Il25 and its receptor subunit, Il17rb, were upregulated during a primary infection and a secondary challenge infection with H. polygyrus bakeri Genetic deletion of IL-25 (IL-25-/-) led to an attenuated type 2 cytokine response and increased worm fecundity in mice with a primary H. polygyrus bakeri infection. In addition, the full spectrum of the host memory response against a secondary infection with H. polygyrus bakeri was severely impaired in IL-25-/- mice, including delayed type 2 cytokine responses, an attenuated functional response of the intestinal smooth muscle and epithelium, diminished intestinal smooth muscle hypertrophy/hyperplasia, and impaired worm expulsion. Furthermore, exogenous administration of IL-25 restored the host protective memory response against H. polygyrus bakeri infection in IL-25-/- mice. These data demonstrate that IL-25 is critical for host protective immunity against H. polygyrus bakeri infection, highlighting its potential application as a therapeutic agent against parasitic nematode infection worldwide.

Resistin-like molecule ß is abundantly expressed in foam cells and is involved in atherosclerosis development.

OBJECTIVE: Resistin-like molecule (RELM) ß is a secretory protein homologous to resistin and reportedly contributes to local immune response regulation in gut and bronchial epithelial cells. However, we found that activated macrophages also express RELMß and thus investigated the role of RELMß in the development of atherosclerosis. APPROACH AND RESULTS: It was demonstrated that foam cells in atherosclerotic lesions of the human coronary artery abundantly express RELMß. RELMß knockout ((-/-)) and wild-type mice were mated with apolipoprotein E-deficient background mice. RELMß(-/-) apolipoprotein E-deficient mice exhibited less lipid accumulation in the aortic root and wall than RELMß(+/+) apolipoprotein E-deficient mice, without significant changes in serum lipid parameters. In vitro, RELMß(-/-) primary cultured peritoneal macrophages (PCPMs) exhibited weaker lipopolysaccharide-induced nuclear factor-κB classical pathway activation and inflammatory cytokine secretion than RELMß(+/+), whereas stimulation with RELMß upregulated inflammatory cytokine expressions and increased expressions of many lipid transporters and scavenger receptors in PCPMs. Flow cytometric analysis revealed inflammatory stimulation-induced RELMß in F4/80(+) CD11c(+) PCPMs. In contrast, the expressions of CD11c and tumor necrosis factor were lower in RELMß(-/-) PCPMs, but both were restored by stimulation with recombinant RELMß. CONCLUSIONS: RELMß is abundantly expressed in foam cells within plaques and contributes to atherosclerosis development via lipid accumulation and inflammatory facilitation.

FIZZ2/RELM-ß induction and role in pulmonary fibrosis.

Found in inflammatory zone (FIZZ) 2, also known as resistin-like molecule (RELM)-ß, belongs to a novel cysteine-rich secreted protein family named FIZZ/RELM. Its function is unclear, but a closely related family member, FIZZ1, has profibrotic activities. The human ortholog of rodent FIZZ1 has not been identified, but human FIZZ2 has significant sequence homology to both rodent FIZZ2 (59%) and FIZZ1 (50%). Given the greater homology to rodent FIZZ2, analyzing the role of FIZZ2 in a rodent model of bleomycin-induced pulmonary fibrosis would be of greater potential relevance to human fibrotic lung disease. The results showed that FIZZ2 was highly induced in lungs of rodents with bleomycin-induced pulmonary fibrosis and of human patients with idiopathic pulmonary fibrosis. FIZZ2 expression was induced in rodent and human lung epithelial cells by Th2 cytokines, which was mediated via STAT6 signaling. The FIZZ2 induction in murine lungs was found to be essential for pulmonary fibrosis, as FIZZ2 deficiency significantly suppressed pulmonary fibrosis and associated enhanced extracellular matrix and cytokine gene expression. In vitro analysis indicated that FIZZ2 could stimulate type I collagen and α-smooth muscle actin expression in lung fibroblasts. Furthermore, FIZZ2 was shown to have chemoattractant activity for bone marrow (BM) cells, especially BM-derived CD11c(+) dendritic cells. Notably, lung recruitment of BM-derived cells was impaired in FIZZ2 knockout mice. These findings suggest that FIZZ2 is a Th2-associated multifunctional mediator with potentially important roles in the pathogenesis of fibrotic lung diseases.

Goblet cell-derived resistin-like molecule beta augments CD4+ T cell production of IFN-gamma and infection-induced intestinal inflammation.

The secreted goblet cell-derived protein resistin-like molecule beta (RELMbeta) has been implicated in divergent functions, including a direct effector function against parasitic helminths and a pathogenic function in promoting inflammation in models of colitis and ileitis. However, whether RELMbeta influences CD4(+) T cell responses in the intestine is unknown. Using a natural model of intestinal inflammation induced by chronic infection with gastrointestinal helminth Trichuris muris, we identify dual functions for RELMbeta in augmenting CD4(+) Th1 cell responses and promoting infection-induced intestinal inflammation. Following exposure to low-dose Trichuris, wild-type C57BL/6 mice exhibit persistent infection associated with robust IFN-gamma production and intestinal inflammation. In contrast, infected RELMbeta(-/-) mice exhibited a significantly reduced expression of parasite-specific CD4(+) T cell-derived IFN-gamma and TNF-alpha and failed to develop Trichuris-induced intestinal inflammation. In in vitro T cell differentiation assays, recombinant RELMbeta activated macrophages to express MHC class II and secrete IL-12/23p40 and enhanced their ability to mediate Ag-specific IFN-gamma expression in CD4(+) T cells. Taken together, these data suggest that goblet cell-macrophage cross-talk, mediated in part by RELMbeta, can promote adaptive CD4(+) T cell responses and chronic inflammation following intestinal helminth infection.

Absence of bacterially induced RELMbeta reduces injury in the dextran sodium sulfate model of colitis.

Although inflammatory bowel disease (IBD) is the result of a dysregulated immune response to commensal gut bacteria in genetically predisposed individuals, the mechanism(s) by which bacteria lead to the development of IBD are unknown. Interestingly, deletion of intestinal goblet cells protects against intestinal injury, suggesting that this epithelial cell lineage may produce molecules that exacerbate IBD. We previously reported that resistin-like molecule beta (RELMbeta; also known as FIZZ2) is an intestinal goblet cell-specific protein that is induced upon bacterial colonization whereupon it is expressed in the ileum and colon, regions of the gut most often involved in IBD. Herein, we show that disruption of this gene reduces the severity of colitis in the dextran sodium sulfate (DSS) model of murine colonic injury. Although RELMbeta does not alter colonic epithelial proliferation or barrier function, we show that recombinant protein activates macrophages to produce TNF-alpha both in vitro and in vivo. RELMbeta expression is also strongly induced in the terminal ileum of the SAMP1/Fc model of IBD. These results suggest a model whereby the loss of epithelial barrier function by DSS results in the activation of the innate mucosal response by RELMbeta located in the lumen, supporting the hypothesis that this protein is a link among goblet cells, commensal bacteria, and the pathogenesis of IBD.

Mechanism of benzo(a)pyrene induction of alpha-human chorionic gonadotropin gene expression in human lung tumor cells.

Human lung cells (ChaGo) derived from a bronchogenic carcinoma synthesize and secrete in the culture medium the alpha subunit of the glycoprotein hormone, human chorionic gonadotropin (alpha-hCG). The synthesis of alpha-hCG by ChaGo cells could be further stimulated by treatment with sublethal concentrations of the polycyclic aromatic hydrocarbons (PAHs), benzo(a)pyrene (BaP), or dimethylbenzanthracene. The production of alpha-hCG could be correlated to the levels of alpha-hCG-specific mRNA sequences in control and PAH-treated cells. Further analysis of the RNA species (Northern blot) revealed that the level of the mature (approximately 1.0 kb) and the high molecular weight alpha-hCG specific nuclear RNA sequences (approximately 2.2 and 5 kb) were all greater in PAH-treated cells. Addition of [3H]BaP (0.25 microgram/ml) in the culture medium of ChaGo cells led to immediate uptake of the radioactive compound apparently by simple diffusion. SDS PAGE and subsequent fluorography revealed that the radioactive compound interacted and formed covalent complexes with cytoplasmic and nuclear proteins. This covalent interaction of the [3H]BaP molecule with cellular proteins could be significantly inhibited by either inhibiting the activity of the enzyme aryl hydrocarbon hydroxylase with 7,8-benzoflavone or by reducing the cellular concentration of the enzyme by simultaneous incubation with cycloheximide. These results suggested that in ChaGo cells, the observed covalent complexes were formed by the interaction of the BaP metabolites with cellular proteins. The concentrations at which 7,8-benzoflavone or cycloheximide inhibited formation of metabolites from [3H]BaP and their covalent interaction with cell protein did not affect the BaP-induced stimulation of alpha-hCG gene expression. However, the cytotoxic effects of BaP in ChaGo cells seemed to be exerted by the metabolism of the compounds. Results presented in this report suggest that BaP metabolism and the interaction of the metabolites with cell proteins were not essential for the BaP-induced modulation of alpha-hCG gene expression.

Ectopic pro-opiolipomelanocortin: sequence of cDNA coding for beta-melanocyte-stimulating hormone and beta-endorphin.

A recombinant bacterial plasmid, pMS1, was constructed that contains 318 nucleotides complementary to a portion of pro-opiolipomelanocortin (proOLMC) messenger RNA from an ectopic adrenocorticotropin-producing tumor. The cloned complementary DNA insert, which contains the sequence that codes for all of the beta-melanocyte-stimulating hormone and beta-endorphin portions of proOLMC, as well as the 3' nontranslated section, is identical to the genomic sequence. Hybridization of tumor proOLMC complementary DNA to RNA subjected to electrophoresis and transferred to a nitrocellulose filter revealed two proOLMC messenger RNA species in the tumor polyadenylated RNA, but only one in pituitary polyadenylated RNA. At least one of the tumor proOLMC messenger RNA's is similar, if not identical, to human pituitary proOLMC messenger RNA.

Chronic features of allergic asthma are enhanced in the absence of resistin-like molecule-beta.

Asthma is characterized by inflammation and architectural changes in the lungs. A number of immune cells and mediators are recognized as initiators of asthma, although therapeutics based on these are not always effective. The multifaceted nature of this syndrome necessitate continued exploration of immunomodulators that may play a role in pathogenesis. We investigated the role of resistin-like molecule-beta (RELM-ß), a gut antibacterial, in the development and pathogenesis of Aspergillus-induced allergic airways disease. Age and gender matched C57BL/6J and Retnlb-/- mice rendered allergic to Aspergillus fumigatus were used to measure canonical markers of allergic asthma at early and late time points. Inflammatory cells in airways were similar, although Retnlb-/- mice had reduced tissue inflammation. The absence of RELM-ß elevated serum IgA and pro-inflammatory cytokines in the lungs at homeostasis. Markers of chronic disease including goblet cell numbers, Muc genes, airway wall remodelling, and hyperresponsiveness were greater in the absence RELM-ß. Specific inflammatory mediators important in antimicrobial defence in allergic asthma were also increased in the absence of RELM-ß. These data suggest that while characteristics of allergic asthma develop in the absence of RELM-ß, that RELM-ß may reduce the development of chronic markers of allergic airways disease.

Altered proopiomelanocortin gene expression in adrenocorticotropin-producing nonpituitary tumors. Comparative studies with corticotropic adenomas and normal pituitaries.

In order to assess the mechanisms of proopiomelanocortin (POMC) gene expression in human ACTH-producing tumors, we performed the simultaneous evaluation of POMC products and messenger RNA (mRNA) in tissue fragments obtained from two corticotropic adenomas, five nonpituitary tumors, and two normal human pituitaries. The POMC products were examined using a combination of gel exclusion chromatography and four different radioimmunoassays directed against gamma 3 melanocyte stimulating hormone (gamma 3MSH), ACTH, gamma-lipotropin (gamma LPH), and beta-endorphin. The POMCmRNA was detected and analyzed by dot and northern blot hybridization using a single-stranded genomic DNA probe corresponding to the coding region of the human POMC gene. Tissue concentrations of POMC products and mRNA showed parallel distributions. Immunoreactive gamma 3MSH and gamma LPH patterns revealed only 16-kD fragment- and gamma LPH-like peptides in normal and tumoral pituitaries; additional gamma 3MSH- and/or beta MSH-like peptides were found in all five nonpituitary tumors. A single POMCmRNA of approximately 1,200 bases (b) was detected in normal and tumoral pituitaries; a single identical POMCmRNA was also found in four nonpituitary tumors. A thymic carcinoid tumor, in addition to the 1,200-b POMCmRNA, contained equal amounts of a second larger POMCmRNA of approximately 1,450 b. It is concluded that POMC gene expression appears qualitatively unaltered in corticotropic adenomas. In nonpituitary tumors, in contrast, abnormal POMC processing is frequent; in addition, an extra POMCmRNA was detected in a thymic tumor with a greater length than the normal mRNA; the mechanisms and pathophysiological implications of these modifications remain to be elucidated.

Adenovirus-mediated chronic "hyper-resistinemia" leads to in vivo insulin resistance in normal rats.

We investigated the chronic in vivo effect of resistin on insulin sensitivity and glucose metabolism by overexpressing resistin protein in male Wistar rats using intravenous administration of an adenovirus encoding mouse resistin. After 7 days of elevated resistin levels at a supraphysiological concentration, the animals displayed glucose intolerance and hyperinsulinemia during glucose tolerance tests, and insulin tolerance tests demonstrated an impaired glucose-lowering effect of insulin. The glucose clamp studies were performed at submaximal (4 mU/kg/min) and maximal (25 mU/kg/min) insulin infusion rates and demonstrated the presence of insulin resistance induced by elevated resistin levels. Indeed, the insulin-stimulated glucose infusion rate was decreased by 12-31%; suppression of hepatic glucose output was attenuated by 28-55%; and insulin suppression of circulating FFA levels was inhibited by 7%. Insulin receptor substrate-1 and -2 phosphorylation and Akt activation were impaired in muscle and adipose tissue. Interestingly, activation of AMP-activated protein kinase in skeletal muscle, liver, and adipose tissue was also significantly downregulated. Together, these results indicate that chronic "hyper-resistinemia" leads to whole-body insulin resistance involving impaired insulin signaling in skeletal muscle, liver, and adipose tissue, resulting in glucose intolerance, hyperinsulinemia, and hypertriglyceridemia. Thus elevated resistin levels in normal rats fed a regular chow diet produce many of the features of human syndrome X.

Role of resistin in diet-induced hepatic insulin resistance.

Resistin is an adipose-derived hormone postulated to link adiposity to insulin resistance. To determine whether resistin plays a causative role in the development of diet-induced insulin resistance, we lowered circulating resistin levels in mice by use of a specific antisense oligodeoxynucleotide (ASO) directed against resistin mRNA and assessed in vivo insulin action by the insulin-clamp technique. After 3 weeks on a high-fat (HF) diet, mice displayed severe insulin resistance associated with an approximately 80% increase in plasma resistin levels. In particular, the rate of endogenous glucose production (GP) increased more than twofold compared with that in mice fed a standard chow. Treatment with the resistin ASO for 1 week normalized the plasma resistin levels and completely reversed the hepatic insulin resistance. Importantly, in this group of mice, the acute infusion of purified recombinant mouse resistin, designed to acutely elevate the levels of circulating resistin up to those observed in the HF-fed mice, was sufficient to reconstitute hepatic insulin resistance. These results provide strong support for a physiological role of resistin in the development of hepatic insulin resistance in this model.

Localization of RELM-ß/FIZZ2 Is Associated with Cementum Formation.

Resistin-like molecule-ß/found in inflammatory zone 2 (RELM-ß/FIZZ2) is a cysteine-rich secretory protein that is localized in the epithelium of the gastrointestinal tract and lung alveoli. Previous reports have suggested that this protein regulates glucose metabolism and inflammation. In the present study, to analyze the involvement of RELM-ß/FIZZ2 in tooth development, we immunohistochemically examined the localization of RELM-ß/FIZZ2 in tooth germs of embryonic days (E) 15-20 and postnatal days (P) 7-42 rats. RELM-ß/FIZZ2 was hardly detected in the tooth germ at the bud (E15) stage. However, at the cap (E17) and bell (E20) stages, this protein was detectable in the inner enamel epithelium; whereas cells in the other parts of the enamel organ including the outer enamel epithelium and stellate reticulum did not show the immunoreactivity. During the root formation stage (P14-28), cells in Hertwig's epithelial root sheath (HERS) localized RELM-ß/FIZZ2. Intense immunoreactivity was also seen in the matrix of the root dentin facing the HERS and the dental follicle. This reactivity was not present on the more upwardly located dentin surface. In contrast, cementum matrix positive for osteopontin and bone sialoprotein was observed on the dentin instead of immunoreactivity for RELM-ß/FIZZ2. Osterix-positive cells, indicating cementoblast progenitors, were also detected in the dental follicle near the matrix positive for RELM-ß/FIZZ2. These results suggest that RELM-ß/FIZZ2 secreted by the inner enamel epithelium was mainly localized in the matrix at the surface of the apical root dentin and might be involved in cementogenesis. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1865-1874, 2017. © 2017 Wiley Periodicals, Inc.

Altered expression of goblet cell- and mucin glycosylation-related genes in the intestinal epithelium during infection with the nematode Nippostrongylus brasiliensis in rat.

Intestinal nematode infection induces marked goblet cell hyperplasia and mucus secretion, but the mechanisms of regulation of the changes still remain to be elucidated. In the present study, epithelial cells were isolated from the rat small intestine at various times after Nippostrongylus brasiliensis infection, and the levels of expression of goblet cell- and mucin glycosylation-related genes were estimated by semi-quantitative reverse transcription (RT)-PCR. Among the genes investigated, mucin core peptide (MUC) 2, sialyltransferase (Siat) 4c and trefoil factor family (TFF) 3 were upregulated as early as 2-4 days post-infection, suggesting that they are associated with an early innate protective response. Seven days post-infection and thereafter, when the nematodes reached maturity, significant upregulation of MUC3, MUC4, resistin-like molecule beta (Relmbeta) and 3O-sulfotransferase (3ST)1 was observed, while 3ST2 expression levels increased after the majority of the worms were expelled from the intestine. Similar alterations of glycosylation-related gene expression were also observed in mast-cell-deficient Ws/Ws rats, suggesting that mast cells in the epithelium are not relevant to the upregulation of these genes. The present finding that the expression level of each goblet cell- or glycosylation-related gene was altered differently during the time course of infection indicates the progression of sequential qualitative changes in the mucus layer after infection.

Expression of the atrial natriuretic factor gene in small cell lung cancer tumors and tumor cell lines.

Hyponatremia in patients with small cell lung cancer can be caused by tumor production of arginine vasopressin (AVP) and result in the syndrome of inappropriate antidiuretic hormone. In evaluating the expression of AVP mRNA from tumor and tumor cell line specimens from five patients with small cell lung cancer and hyponatremia (presumed to have the syndrome of inappropriate antidiuretic hormone), we found that the tumors and tumor cell lines from two of these five patients expressed AVP mRNA. The RNA samples from the three patients with undetectable AVP mRNA expressed abundant atrial natriuretic factor (ANF) mRNA. Analysis of specimens from three patients with small cell lung cancer and normal serum sodium levels revealed no detectable AVP mRNA expression, and samples from only one of these three patients' specimens expressed detectable ANF mRNA. The AVP and ANF peptide levels in lysate preparations of the tumor cell lines from four of these patients were tested by radioimmunoassay and confirmed the gene expression data. These studies demonstrate ectopic production of ANF mRNA in small cell lung cancer specimens from patients with this cancer and the syndrome of inappropriate antidiuretic hormone. These findings will be of particular interest if future studies demonstrate that ectopic ANF production can cause sodium abnormalities in patients with small cell lung cancer.

Involvement of resistin-like molecule ß in the development of methionine-choline deficient diet-induced non-alcoholic steatohepatitis in mice.

Resistin-like molecule ß (RELMß) reportedly has multiple functions including local immune responses in the gut. In this study, we investigated the possible contribution of RELMß to non-alcoholic steatohepatitis (NASH) development. First, RELMß knock-out (KO) mice were shown to be resistant to methionine-choline deficient (MCD) diet-induced NASH development. Since it was newly revealed that Kupffer cells in the liver express RELMß and that RELMß expression levels in the colon and the numbers of RELMß-positive Kupffer cells were both increased in this model, we carried out further experiments using radiation chimeras between wild-type and RELMß-KO mice to distinguish between the contributions of RELMß in these two organs. These experiments revealed the requirement of RELMß in both organs for full manifestation of NASH, while deletion of each one alone attenuated the development of NASH with reduced serum lipopolysaccharide (LPS) levels. The higher proportion of lactic acid bacteria in the gut microbiota of RELMß-KO than in that of wild-type mice may be one of the mechanisms underlying the lower serum LPS level the former. These data suggest the contribution of increases in RELMß in the gut and Kupffer cells to NASH development, raising the possibility of RELMß being a novel therapeutic target for NASH.

The goblet cell-derived mediator RELM-ß drives spontaneous colitis in Muc2-deficient mice by promoting commensal microbial dysbiosis.

Intestinal goblet cells are potentially key players in controlling susceptibility to ulcerative colitis (UC). Although impaired mucin (Muc2) production by goblet cells increases microbial stimulation of the colonic mucosa, goblet cells secrete other mediators that may influence or promote UC development. Correspondingly, Muc2-deficient ((-/-)) mice develop spontaneous colitis, concurrent with the dramatic upregulation of the goblet cell mediator, resistin-like molecule-beta (RELM-ß). Testing RELM-ß's role, we generated Muc2(-/-)/Retnlb(-/-) mice, finding that RELM-ß deficiency significantly attenuated colitis development and symptoms compared with Muc2(-/-) mice. RELM-ß expression in Muc2(-/-) mice strongly induced the production/secretion of the antimicrobial lectin RegIIIß, that exerted its microbicidal effect predominantly on Gram-positive Lactobacillus species. Compared with Muc2(-/-)/Retnlb(-/-) mice, this worsened intestinal microbial dysbiosis with a selective loss of colonic Lactobacilli spp. in Muc2(-/-) mice. Orally replenishing Muc2(-/-) mice with murine Lactobacillus spp., but not with a probiotic formulation containing several human Lactobacillus spp. (VSL#3), ameliorated their spontaneous colitis in concert with increased production of short-chain fatty acids. These studies demonstrate that the goblet cell mediator RELM-ß drives colitis in Muc2(-/-) mice by depleting protective commensal microbes. The ability of selective commensal microbial replacement to ameliorate colitis suggests that personalized bacterial therapy may prove beneficial for treatment of UC.