Cellular Plasticity of Defa4Cre-Expressing Paneth Cells in Response to Notch Activation and Intestinal Injury.

BACKGROUND & AIMS: Loss of leucine-rich repeat-containing G-protein-coupled receptor 5-positive crypt base columnar cells provides permissive conditions for different facultative stem cell populations to dedifferentiate and repopulate the stem cell compartment. In this study, we used a defensin α4-Cre recombinase (Defa4Cre) line to define the potential of Paneth cells to dedifferentiate and contribute to intestinal stem cell (ISC) maintenance during normal homeostasis and after intestinal injury. METHODS: Small intestine and enteroids from Defa4Cre;Rosa26 tandem dimer Tomato (tdTomato), a red fluoresent protein, (or Rosa26 Enhanced Yellow Fluorescent Protein (EYFP)) reporter, Notch gain-of-function (Defa4Cre;Rosa26 Notch Intracellular Domain (NICD)-ires-nuclear Green Fluorescent Protein (nGFP) and Defa4Cre;Rosa26reverse tetracycline transactivator-ires Enhanced Green Fluorescent Protein (EGFP);TetONICD), A Disintegrin and Metalloproteinase domain-containing protein 10 (ADAM10) loss-of-function (Defa4Cre;ADAM10flox/flox), and Adenomatous polyposis coli (APC) inactivation (Defa4Cre;APCflox/flox) mice were analyzed. Doxorubicin treatment was used as an acute intestinal injury model. Lineage tracing, proliferation, and differentiation were assessed in vitro and in vivo. RESULTS: Defa4Cre-expressing cells are fated to become mature Paneth cells and do not contribute to ISC maintenance during normal homeostasis in vivo. However, spontaneous lineage tracing was observed in enteroids, and fluorescent-activated cell sorter-sorted Defa4Cre-marked cells showed clonogenic enteroid growth. Notch activation in Defa4Cre-expressing cells caused dedifferentiation to multipotent ISCs in vivo and was required for adenoma formation. ADAM10 deletion had no significant effect on crypt homeostasis. However, after acute doxorubicin-induced injury, Defa4Cre-expressing cells contributed to regeneration in an ADAM10-Notch-dependent manner. CONCLUSIONS: Our studies have shown that Defa4Cre-expressing Paneth cells possess cellular plasticity, can dedifferentiate into multipotent stem cells upon Notch activation, and can contribute to intestinal regeneration in an acute injury model.

Interaction between smoking and ATG16L1T300A triggers Paneth cell defects in Crohn's disease.

It is suggested that subtyping of complex inflammatory diseases can be based on genetic susceptibility and relevant environmental exposure (G+E). We propose that using matched cellular phenotypes in human subjects and corresponding preclinical models with the same G+E combinations is useful to this end. As an example, defective Paneth cells can subtype Crohn's disease (CD) subjects; Paneth cell defects have been linked to multiple CD susceptibility genes and are associated with poor outcome. We hypothesized that CD susceptibility genes interact with cigarette smoking, a major CD environmental risk factor, to trigger Paneth cell defects. We found that both CD subjects and mice with ATG16L1T300A (T300A; a prevalent CD susceptibility allele) developed Paneth cell defects triggered by tobacco smoke. Transcriptional analysis of full-thickness ileum and Paneth cell-enriched crypt base cells showed the T300A-smoking combination altered distinct pathways, including proapoptosis, metabolic dysregulation, and selective downregulation of the PPARγ pathway. Pharmacologic intervention by either apoptosis inhibitor or PPARγ agonist rosiglitazone prevented smoking-induced crypt apoptosis and Paneth cell defects in T300A mice and mice with conditional Paneth cell-specific knockout of Atg16l1. This study demonstrates how explicit G+E can drive disease-relevant phenotype and provides rational strategies for identifying actionable targets.

Loss of Paneth Cell Autophagy Causes Acute Susceptibility to Toxoplasma gondii-Mediated Inflammation.

The protozoan parasite Toxoplasma gondii triggers severe small intestinal immunopathology characterized by IFN-γ- and intestinal microbiota-mediated inflammation, Paneth cell loss, and bacterial dysbiosis. Paneth cells are a prominent secretory epithelial cell type that resides at the base of intestinal crypts and releases antimicrobial peptides. We demonstrate that the microbiota triggers basal Paneth cell-specific autophagy via induction of IFN-γ, a known trigger of autophagy, to maintain intestinal homeostasis. Deletion of the autophagy protein Atg5 specifically in Paneth cells results in exaggerated intestinal inflammation characterized by complete destruction of the intestinal crypts resembling that seen in pan-epithelial Atg5-deficient mice. Additionally, lack of functional autophagy in Paneth cells within intestinal organoids and T. gondii-infected mice causes increased sensitivity to the proinflammatory cytokine TNF along with increased intestinal permeability, leading to exaggerated microbiota- and IFN-γ-dependent intestinal immunopathology. Thus, Atg5 expression in Paneth cells is essential for tissue protection against cytokine-mediated immunopathology during acute gastrointestinal infection.

Therapeutic Endoscopy for the Control of Nonvariceal Upper Gastrointestinal Bleeding in Children: A Case Series.

OBJECTIVES: Gastrointestinal bleeding is one of the most common indications for urgent endoscopy in the pediatric setting. The majority of these procedures are performed for control of variceal bleeding, with few performed for nonvariceal upper gastrointestinal (NVUGI) bleeding. The data on therapeutic endoscopy for NVUGI are sparse. The aims of our study were to review our experience with NVUGI bleeding, describe technical aspects and outcomes of therapeutic endoscopy, and determine gastroenterology fellows' training opportunities according to the national training guidelines. METHODS: We performed a retrospective review of endoscopy database (Endoworks, Olympus Inc, Center Valley, PA) from January 2009 to December 2014. The search used the following keywords: bleeding, hematemesis, melena, injection, epinephrine, cautery, clip, and argon plasma coagulation. The collected data included demographics, description of bleeding lesion and medical/endoscopic therapy, rate of rebleeding, relevant laboratories, physical examination, and need for transfusion and surgery. The study was approved by the institutional review board. RESULTS: During the study period 12,737 upper endoscopies (esophagogastroduodenoscopies) were performed. A total of 15 patients underwent 17 esophagogastroduodenoscopies that required therapeutic intervention to control bleeding (1:750 procedures). The mean ±â€Šstandard deviation (median) age of patients who required endoscopic intervention was 11.6 ±â€Š6.0 years (14.0 years). Seven out of 17 patients received dual therapy to control the bleeding lesions. All but 3 patients received medical therapy with intravenous proton pump inhibitor, and 3 received octreotide infusions. Six of the patients experienced rebleeding (40%), with 4 out of 6 initially only receiving single modality therapy. Two of these patients eventually required surgical intervention to control bleeding and both patients presented with bleeding duodenal ulcers. There were no cases of aspiration, perforation, or deaths. There were a total of 24 fellows trained in our program during the study period. Less than 1 therapeutic endoscopy per fellow for NVUGI bleeding was performed. CONCLUSIONS: NVUGI bleeding requiring therapeutic endoscopic intervention is rare in pediatrics. A high rate (40%) of rebleeding was noted with a large proportion (66%) of patients receiving single modality therapy. Two patients required surgical intervention to control bleeding and both presented with bleeding duodenal ulcers. An insufficient number of therapeutic procedures is available for adequate fellow training requiring supplemental simulator and hands-on animal model, or adult endoscopy unit training.

Tips and Tricks on How to Optimally Manage Patients with Upper Gastrointestinal Bleeding.

Effective endoscopic therapy for upper gastrointestinal (GI) bleeding has been shown to reduce rebleeding, need for surgery, and mortality. Effective endoscopic management of acute upper GI bleeding can be challenging and worrying. This article provides advice that is complementary to the in-depth reviews that accompany it in this issue. Topics include initial management, resuscitation, when and where to scope, benefits and limitations of devices, device selection based on lesion characteristics, improving visualization to localize the lesion, and tips on how to reduce the endoscopist's trepidation about managing these cases.

Leptin acts independently of food intake to modulate gut microbial composition in male mice.

Shifts in the composition of gut bacterial populations can alter host metabolism and may contribute to the pathogenesis of metabolic disorders, including obesity. Mice deficient in leptin action are obese with altered microbiota and increased susceptibility to certain intestinal pathogens. Because antimicrobial peptides (AMPs) secreted by Paneth cells represent a major mechanism by which the host influences the gut microbiome, we examined the mRNA expression of gut AMPs, several of which were decreased in leptin receptor (LepR)-deficient db/db mice, suggesting a potential role for AMP modulation of microbiota composition. To address the extent to which the alterations in gut microbiota and AMP mRNA expression in db/db mice result from increased food intake vs other defects in leptin action, we examined the effects of pair feeding and gut epithelial LepRb ablation on AMP mRNA expression and microbiota composition. We found that the phylum-level changes in fecal microbial content and AMP gene expression persist in pair-fed db/db mice, suggesting that these differences do not stem from hyperphagia alone. In addition, despite recent evidence to support a role for intestinal epithelial LepRb signaling in pathogen susceptibility, ablation of LepRb from the intestinal epithelium fails to alter body weight, composition of the microbiota, or AMP expression, suggesting a role for LepRb elsewhere for this regulation. Indeed, gut LepRb cells are not epithelial but rather constitute a previously uncharacterized population of perivascular cells within the intestinal submucosa. Overall, our data reveal a role for LepRb signaling extrinsic to the intestinal epithelium and independent of food intake in the control of the gut microbiome.

Secretion of the adipocyte-specific secretory protein adiponectin critically depends on thiol-mediated protein retention.

Adiponectin is a secretory protein abundantly secreted from adipocytes. It assembles into a number of different higher-order complexes. Adipocytes maintain tight control over circulating plasma levels, suggesting the existence of a complex, highly regulated biosynthetic pathway. However, the critical mediators of adiponectin maturation within the secretory pathway have not been elucidated. Previously, we found that a significant portion of de novo-synthesized adiponectin is not secreted and retained in adipocytes. Here, we show that there is an abundant pool of properly folded adiponectin in the secretory pathway that is retained through thiol-mediated retention, as judged by the release of adiponectin in response to treatment of adipocytes with reducing agents. Adiponectin is covalently bound to the ER chaperone ERp44. An adiponectin mutant lacking cysteine 39 fails to stably interact with ERp44, demonstrating that this residue is the primary site mediating the covalent interaction. Another ER chaperone, Ero1-Lalpha, plays a critical role in the release of adiponectin from ERp44. Levels of both of these proteins are highly regulated in adipocytes and are influenced by the metabolic state of the cell. While less critical for the secretion of trimers, these chaperones play a major role in the assembly of higher-order adiponectin complexes. Our data highlight the importance of posttranslational events controlling adiponectin levels and the release of adiponectin from adipocytes. One mechanism for increasing circulating levels of specific adiponectin complexes by peroxisome proliferator-activated receptor gamma agonists may be selective upregulation of rate-limiting chaperones.

Mouse and human resistins impair glucose transport in primary mouse cardiomyocytes, and oligomerization is required for this biological action.

The adipocytokine resistin impairs glucose tolerance and insulin sensitivity in rodents. Here, we examined the effect of resistin on glucose uptake in isolated adult mouse cardiomyocytes. Murine resistin reduced insulin-stimulated glucose uptake, establishing the heart as a resistin target tissue. Notably, human resistin also impaired insulin action in mouse cardiomyocytes, providing the first evidence that human and mouse resistin homologs have similar functions. Resistin is a cysteine-rich molecule that circulates as a multimer of a dimeric form dependent upon a single intermolecular disulfide bond, which, in the mouse, involves Cys26; mutation of this residue to alanine (C26A) produces a monomeric molecule that appears to be bioactive in the liver. Remarkably, unlike native resistin, monomeric C26A resistin had no effect on basal or insulin-stimulated glucose uptake in mouse cardiomyocytes. Resistin impairs glucose uptake in cardiomyocytes by mechanisms that involve altered vesicle trafficking. Thus, in cardiomyocytes, both mouse and human resistins directly impair glucose transport; and in contrast to effects on the liver, these actions of resistin require oligomerization.

The hyperglycemia-induced inflammatory response in adipocytes: the role of reactive oxygen species.

Hyperglycemia is a major independent risk factor for diabetic macrovascular disease. The consequences of exposure of endothelial cells to hyperglycemia are well established. However, little is known about how adipocytes respond to both acute as well as chronic exposure to physiological levels of hyperglycemia. Here, we analyze adipocytes exposed to hyperglycemia both in vitro as well as in vivo. Comparing cells differentiated at 4 mm to cells differentiated at 25 mm glucose (the standard differentiation protocol) reveals severe insulin resistance in cells exposed to 25 mm glucose. A global assessment of transcriptional changes shows an up-regulation of a number of mitochondrial proteins. Exposure to hyperglycemia is associated with a significant induction of reactive oxygen species (ROS), both in vitro as well as in vivo in adipocytes isolated from streptozotocin-treated hyperglycemic mice. Furthermore, hyperglycemia for a few hours in a clamped setting will trigger the induction of a pro-inflammatory response in adipose tissue from rats that can effectively be reduced by co-infusion of N-acetylcysteine (NAC). ROS levels in 3T3-L1 adipocytes can be reduced significantly with pharmacological agents that lower the mitochondrial membrane potential, or by overexpression of uncoupling protein 1 or superoxide dismutase. In parallel with ROS, interleukin-6 secretion from adipocytes is significantly reduced. On the other hand, treatments that lead to a hyperpolarization of the mitochondrial membrane, such as overexpression of the mitochondrial dicarboxylate carrier result in increased ROS formation and decreased insulin sensitivity, even under normoglycemic conditions. Combined, these results highlight the importance ROS production in adipocytes and the associated insulin resistance and inflammatory response.

Optimization of protein production in mammalian cells with a coexpressed fluorescent marker.

The expression of mammalian proteins in sufficient abundance and quality for structural studies often presents formidable challenges. Many express poorly in bacterial systems, whereas it can be time consuming and expensive to produce them from cells of higher organisms. Here we describe a procedure for the direct selection of stable mammalian cell lines that express proteins of interest in high yield. Coexpression of a marker protein, such as green fluorescent protein, is linked to that of the desired protein through an internal ribosome entry site in the vector that is transfected into cells in culture. The coexpressed marker is used to select for highly expressing clonal cell lines. Applications are described to a membrane protein, the 5HT2c serotonin receptor, and to a secreted cysteine-rich protein, resistin. Besides providing an expeditious means for producing mammalian proteins for structural work, the resulting cell lines also readily support tests of functional properties and structure-inspired hypotheses.

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.

Regulation of resistin expression and circulating levels in obesity, diabetes, and fasting.

Resistin was originally reported as an adipose tissue-specific hormone that provided a link between obesity and diabetes. Resistin protein level was elevated in obese mice and decreased by insulin-sensitizing thiazolidinediones. Immunoneutralization of resistin improved insulin sensitivity in diet-induced obese mice, while the administration of exogenous resistin induced insulin resistance. More recently, we have shown that ablation of the resistin gene in mice decreased fasting glucose through impairment of gluconeogenesis, while resistin treatment in these knockout mice increased hepatic glucose production. However, the link between resistin and glucose homeostasis has been questioned by studies demonstrating reduced, rather than increased, resistin mRNA expression in obese and diabetic mice. To better understand the regulation of resistin, we developed a sensitive and specific RIA resistin that could accurately measure serum resistin levels in several mouse models. We show that while resistin mRNA is indeed suppressed in obese mice, the circulating resistin level is significantly elevated and positively correlated with insulin, glucose, and lipids. Both resistin mRNA expression and protein levels in Lep(ob/ob) mice are suppressed by leptin treatment in parallel with reductions in glucose and insulin. In wild-type mice, serum resistin increases after nocturnal feeding, concordant with rising levels of insulin. Resistin mRNA and protein levels decline in parallel with glucose and insulin during fasting and are restored after refeeding. We performed clamp studies to determine whether resistin is causally related to insulin and glucose. Adipose resistin expression and serum resistin increased in response to hyperinsulinemia and further in response to hyperglycemia. Taken together, these findings suggest that the nutritional regulation of resistin and changes in resistin gene expression and circulating levels in obesity are mediated, at least in part, through insulin and glucose.

Disulfide-dependent multimeric assembly of resistin family hormones.

Resistin, founding member of the resistin-like molecule (RELM) hormone family, is secreted selectively from adipocytes and induces liver-specific antagonism of insulin action, thus providing a potential molecular link between obesity and diabetes. Crystal structures of resistin and RELMbeta reveal an unusual multimeric structure. Each protomer comprises a carboxy-terminal disulfide-rich beta-sandwich "head" domain and an amino-terminal alpha-helical "tail" segment. The alpha-helical segments associate to form three-stranded coiled coils, and surface-exposed interchain disulfide linkages mediate the formation of tail-to-tail hexamers. Analysis of serum samples shows that resistin circulates in two distinct assembly states, likely corresponding to hexamers and trimers. Infusion of a resistin mutant, lacking the intertrimer disulfide bonds, in pancreatic-insulin clamp studies reveals substantially more potent effects on hepatic insulin sensitivity than those observed with wild-type resistin. This result suggests that processing of the intertrimer disulfide bonds may reflect an obligatory step toward activation.

Regulation of fasted blood glucose by resistin.

The association between obesity and diabetes supports an endocrine role for the adipocyte in maintaining glucose homeostasis. Here we report that mice lacking the adipocyte hormone resistin exhibit low blood glucose levels after fasting, due to reduced hepatic glucose production. This is partly mediated by activation of adenosine monophosphate-activated protein kinase and decreased expression of gluconeogenic enzymes in the liver. The data thus support a physiological function for resistin in the maintenance of blood glucose during fasting. Remarkably, lack of resistin diminishes the increase in post-fast blood glucose normally associated with increased weight, suggesting a role for resistin in mediating hyperglycemia associated with obesity.

Minireview: The adipocyte--at the crossroads of energy homeostasis, inflammation, and atherosclerosis.

Adipose tissue evolved to efficiently store energy for times of caloric restriction. The large caloric excess common in many Western diets has negated the need for this thrifty function, leaving adipose tissue ill-equipped to handle this increased load. An excess of adipose tissue increases risk for a number of conditions including coronary artery disease, hypertension, dyslipidemias, type 2 diabetes, and even cancer. Indeed, the ability of the adipocyte to function properly when engorged with lipid can lead to lipid accumulation in other tissues, reducing their ability to function and respond normally. The role of adipose tissue as an endocrine organ capable of secreting a number of adipose tissue-specific or enriched hormones, known as adipokines, is gaining appreciation. The normal balance of these adipose tissue secretory proteins is perturbed in obesity. Paradoxically, the lack of normal adipose tissue, as seen in cases of lipodystrophy and lipoatrophy, is also associated with pathologic sequelae similar to what is seen with obesity. The pathologic findings associated with lack of adipose tissue, largely due to inability to properly store lipids, may also be due to a lack of adipokines. In this review, we highlight the role of adipose tissue as an endocrine organ focusing on some of the recent advances in the identification and pharmacological characterization of adipokines as well as their regulation in the context of obesity and insulin-resistant states.

Adipose-derived resistin and gut-derived resistin-like molecule-beta selectively impair insulin action on glucose production.

The adipose-derived hormone resistin is postulated to link obesity to insulin resistance and diabetes. Here, the infusion of either resistin or the resistin-like molecule-beta (RELMbeta) rapidly induced severe hepatic but not peripheral insulin resistance. In the presence of physiologic hyperinsulinemia, the infusion of purified recombinant resistin, increasing circulating resistin levels by approximately twofold to 15-fold, inhibited glucose metabolism such that lower rates of glucose infusion were required to maintain the plasma glucose concentration at basal levels. The effects of resistin and RELMbeta on in vivo insulin action were completely accounted for by a marked increase in the rate of glucose production. These results support the notion that a novel family of fat- and gut-derived circulating proteins modulates hepatic insulin action.

Structure-function studies of the adipocyte-secreted hormone Acrp30/adiponectin. Implications fpr metabolic regulation and bioactivity.

Acrp30/adiponectin is an adipocyte-specific secretory protein that has recently been implicated as a mediator of systemic insulin sensitivity with liver and muscle as target organs. Acrp30 is found as two forms in serum, as a lower molecular weight trimer-dimer and a high molecular weight complex. Little is know about the regulation and significance of these Acrp30 complexes in serum and about the events that lead to the generation of the bioactive ligand. Here, we show that there is a profound sexual dimorphism of Acrp30 levels and complex distribution in serum. Female mice display significantly higher levels of the high molecular weight complex in serum than males. In both females and males, levels of the high molecular weight complex are significantly reduced in response to a systemic increase of insulin. The ratio of the two complexes is restored upon normalization of glucose levels. Structurally, we show that oligomer formation of Acrp30 critically depends on disulfide bond formation mediated by Cys-39. Mutation of Cys-39 results in trimers that are subject to proteolytic cleavage in the collagenous domain. Surprisingly, Acrp30(C39S) or wild-type Acrp30 treated with dithiothreitol are significantly more bioactive than the higher order oligomeric forms of the protein with respect to reduction of serum glucose levels. Furthermore, treatment of primary hepatocytes with trimeric and higher order forms of Acrp30 confirms that the increased bioactivity seen in vivo is reflected in an augmented potency to reduce glucose output in the presence of gluconeogenic stimuli. Combined, these results shed new light on the regulation of this complex protein and suggest a new model for in vivo activation of the protein, implicating a serum reductase activity.

Removal of visceral fat prevents insulin resistance and glucose intolerance of aging: an adipokine-mediated process?

Age-dependent changes in insulin action and body fat distribution are risk factors for the development of type 2 diabetes. To examine whether the accumulation of visceral fat (VF) could play a direct role in the pathophysiology of insulin resistance and type 2 diabetes, we monitored insulin action, glucose tolerance, and the expression of adipo-derived peptides after surgical removal of VF in aging (20-month-old) F344/Brown Norway (FBN) and in Zucker Diabetic Fatty (ZDF) rats. As expected, peripheral and hepatic insulin action were markedly impaired in aging FBN rats, and extraction of VF (accounting for approximately 18% of their total body fat) was sufficient to restore peripheral and hepatic insulin action to the levels of young rats. When examined at the mechanistic level, removal of VF in ZDF rats prevented the progressive decrease in insulin action and delayed the onset of diabetes, but VF extraction did not alter plasma free fatty acid levels. However, the expression of tumor necrosis factor-alpha and leptin in subcutaneous (SC) adipose tissue were markedly decreased after VF removal (by approximately three- and twofold, respectively). Finally, extracted VF retained approximately 15-fold higher resistin mRNA compared with SC fat. Our data suggest that insulin resistance and the development of diabetes can be significantly reduced in aging rats by preventing the age-dependent accumulation of VF. This study documents a cause-and-effect relationship between VF and major components of the metabolic syndrome.

Cell type-specific expression and coregulation of murine resistin and resistin-like molecule-alpha in adipose tissue.

Adipocytes are the exclusive or predominant source of several secreted proteins that exert profound effects on systemic carbohydrate and lipid metabolism. Resistin, a 10-kDa adipose tissue specific secretory protein, has recently been implicated in exerting a negative effect on systemic insulin sensitivity. It is, however, not known how resistin mediates this insulin-desensitizing effect or what regulatory mechanisms control resistin expression. Resistin-like molecule-alpha (RELMalpha), a homolog of resistin originally identified by its upregulation in asthmatic lung, is another secreted protein expressed in adipose tissue. The regulation of RELMalpha in adipose tissue and its relationship to resistin expression has not been addressed so far. Here, we demonstrate that the expression of resistin and RELMalpha are similarly regulated in adipose tissue despite the fact that RELMalpha is exclusively expressed in the stromal vascular fraction of adipose tissue and not in adipocytes. Interestingly, this coregulation is limited to adipose tissue as the expression of RELMalpha in lung is independent of metabolic regulation. Additionally, we show that resistin and RELMalpha levels are not subject to regulation by proinflammatory stimuli. Finally, acute hyperglycemia leads to up-regulation of resistin and RELMalpha transcription in various adipose depots.