Previous studies have reported that ST2 is preferentially expressed on Th2 cells and plays a critical part in controlling airway inflammation in murine models of asthma. However, the clinical role of ST2 in patients with bronchial asthma remains unclear. In our study, we examined 56 patients with atopic asthma in a nonattack phase and 200 nonatopic normal volunteers for healthy control, and analyzed the relationship of their serum ST2 levels to asthma severity, pulmonary function, and laboratory data. Of the 56 patients with atopic asthma, 30 exhibited asthmatic exacerbation, and their serum ST2 levels were also analyzed. The serum ST2 levels were low, but a statistical difference was found between patients with nonattack asthma and the healthy control group (p < 0.05). We also found a differential rise of serum ST2 level that correlates well with the severity of asthma exacerbation. Furthermore, the serum ST2 levels during asthma exacerbation statistically correlated with the percentage of predicted peak expiratory flow (r = -0.634, p = 0.004) and Pa(CO(2)) (r = 0.516, p = 0.003). These results suggest that soluble human ST2 protein in sera may be related to Th2-mediated allergic inflammation inducing acute exacerbation in patients with atopic asthma.
Abstract. Current models for nucleotide sugar use in the Golgi apparatus predict a critical role for the lumenal nucleoside diphosphatase. After transfer of sugars to endogenous macromolecular acceptors, the enzyme converts nucleoside diphosphates to nucleoside monophosphates which in turn exit the Golgi lumen in a coupled antiporter reaction, allowing entry of additional nucleotide sugar from the cytosol. To test this model, we cloned the gene for the S. cerevisiae guanosine diphosphatase and constructed a null mutation. This mutation should reduce the concentrations of GDP-mannose and GMP and increase the concentration of GDP in the Golgi lumen. The alterations should in turn decrease mannosylation of proteins and lipids in this compartment. In fact, we found a partial block in O-and N-glycosylation of proteins such as chitinase and carboxypeptidase Y and underglycosylation of invertase. In addition, mannosylinositolphosphorylceramide levels were drastically reduced.
The ST2 gene encodes receptor-like molecules that are very similar to the type I interleukin-1 receptor. Two distinct types of the ST2 gene products, ST2 (a soluble secreted form) and ST2L (a transmembrane form) are produced by alternative splicing. Here we demonstrate that the human ST2 gene has two alternative promoters followed by distinct noncoding first exons, which are located more than 8 kb apart and are spliced to the common exon 2 containing the translation initiation site. Within 1001 bp upstream of the transcription initiation site of the cloned distal promoter, there are four GATA-1. The main promoter used for the expression of the ST2 gene in UT-7, a human leukaemic cell line, is distinct from that in TM12, a human fibroblastic cell line. Although UT-7 cells use both distal and proximal promoters, the distal promoter is used dominantly for expression of both ST2 and ST2L mRNA. On the other hand, almost all transcription in TM12 cells starts from the proximal promoter. These results contrast with those of former studies on the rat system, in which ST2 and ST2L mRNA were generated by use of the proximal and distal promoters, respectively. Furthermore, UT-7 cells use multiple transcription initiation sites in both the proximal and distal promoters, whereas the transcription of the ST2 gene in TM12 cells starts at a unique site. Intriguingly, these results suggest that ST2 and ST2L proteins have distinct functions in different cells within different biological systems, such as those of growth control, differentiation and immunological responses.Keywords: immunoglobulin superfamily; interleukin-1 receptor-related protein; orphan receptor; promoter usage; ST2 gene.The ST2 gene, also designated as T1, Fit-1 or DER4, was cloned as one of the primary response genes in the G 0 /G 1 transitional state of BALB/c-3T3 cells [1], a H-ras oncogeneresponsive gene [2], a Fos-responsive gene [3], and a delayed early serum response gene [4]. Subsequently, ST2L cDNA, encoding a membrane-bound protein the extracellular domain of which is almost identical to the ST2 protein, was cloned [5]. The mRNAs of ST2 and ST2L were produced by alternative 3 H splicing of the primary transcript of the ST2 gene [6]. Based on this discovery of the ST2 gene and its expression in fibroblastic cell lines, our previous studies focused on the function of the ST2 gene in growth control.On the other hand, structural analysis of the ST2 cDNA revealed that the ST2 protein was remarkably similar to the members of the immunoglobulin superfamily, especially to the extracellular portion of the mouse interleukin-1 receptor (IL-1R) [1], and the ST2L protein showed a striking overall similarity to the mouse type I interleukin (IL)-1 receptor (IL-1RI) [5]. Furthermore, the genes encoding ST2 and the two IL-1 receptors, IL-1RI and IL-1RII, were tightly linked on mouse chromosome 1 [7] and human chromosome 2 [8]. The human ST2 gene was assigned to chromosome 2q11.2 [9]. However, IL-1a, b, and receptor antagonist did not bind to the ST2L protein, suggesti...
Atopic dermatitis (AD) is a common inflammatory skin disease associated with the local infiltration of T helper type 2 (Th2) cells. The ST2 gene encodes both membrane-bound ST2L and soluble ST2 (sST2) proteins by alternative splicing. The orphan receptor ST2L is functionally indispensable for Th2 cells. We found a significant genetic association between AD and the -26999G/A single nucleotide polymorphism (SNP) (chi2-test, raw P-value=0.000007, odds ratio 1.86) in the distal promoter region of the ST2 gene (chromosome 2q12) in a study of 452 AD patients and 636 healthy controls. The -26999A allele common among AD patients positively regulates the transcriptional activity of the ST2 gene. In addition, having at least one -26999A allele correlated with high sST2 concentrations and high total IgE levels in the sera from AD patients. Thus, the -26999A allele is correlated with an increased risk for AD. We also found that the -26999G/A SNP predominantly affected the transcriptional activity of hematopoietic cells. Immunohistochemical staining of a skin biopsy specimen from an AD patient in the acute stage showed ST2 staining in the keratinocytes as well as in the infiltrating cells in the dermal layer. Our data show that functional SNPs in the ST2 distal promoter region regulate ST2 expression which induces preferential activation of the Th2 response. Our findings will contribute to the evaluation of one of the genetic risk factors for AD.
In the course of studying the ST2 gene, which was initially found to be expressed specifically at the C&G, transitional state in BALBlc-3T3 cells and was one of the primary response genes, we found another ST2-related mRNA, designated as STZL, in serum-stimulated BALB/c-3T3 cells in the presence of cycloheximide. Nucleotide sequence analysis of the cloned STZL cDNA revealed that it had an open reading frame encoding a polypeptide of 567 amino acids. A 5' region (1,028 nucleotides) of STZL cDNA was identical with the ST2 cDNA, and a unique 3' region encoded 'a putative transmembrane domain of 24 amino acids and a cytoplasmic domain of 201 amino acids. The ST2 gene product is highly similar to the extracellular portion of IL-I receptors type 1 and type 2, and the STZL gene product shows a marked similarity with entire IL-l receptor type I.
Objective. This update of the 2008 American Academy of Otolaryngology-Head and Neck Surgery Foundation cerumen impaction clinical practice guideline provides evidencebased recommendations on managing cerumen impaction. Cerumen impaction is defined as an accumulation of cerumen that causes symptoms, prevents assessment of the ear, or both. Changes from the prior guideline include• a consumer added to the development group;• new evidence (3 guidelines, 5 systematic reviews, and 6 randomized controlled trials); • enhanced information on patient education and counseling; • a new algorithm to clarify action statement relationships;• expanded action statement profiles to explicitly state quality improvement opportunities, confidence in the evidence, intentional vagueness, and differences of opinion; • an enhanced external review process to include public comment and journal peer review; and • 3 new key action statements on managing cerumen impaction that focus on primary prevention, contraindicated intervention, and referral and coordination of care.Purpose. The primary purpose of this guideline is to help clinicians identify patients with cerumen impaction who may benefit from intervention and to promote evidence-based management. Another purpose of the guideline is to highlight needs and management options in special populations or in patients who have modifying factors. The guideline is intended for all clinicians who are likely to diagnose and manage patients with cerumen impaction, and it applies to any setting in which cerumen impaction would be identified, monitored, or managed. The guideline does not apply to patients with cerumen impaction associated with the following conditions: dermatologic diseases of the ear canal; recurrent otitis externa; keratosis obturans; prior radiation therapy affecting the ear; previous tympanoplasty/myringoplasty, canal wall down mastoidectomy, or other surgery affecting the ear canal.Key Action Statements. The panel made a strong recommendation that clinicians should treat, or refer to a clinician who can treat, cerumen impaction, defined as an accumulation of cerumen that is associated with symptoms, prevents needed assessment of the ear, or both.The panel made the following recommendations: (1) Clinicians should explain proper ear hygiene to prevent cerumen impaction when patients have an accumulation of cerumen. (2) Clinicians should diagnose cerumen impaction when an accumulation of cerumen, as seen on otoscopy, is associated with symptoms, prevents needed assessment of the ear, or both. (3) Clinicians should assess the patient with cerumen impaction by history and/or physical examination for factors that modify management, such as ≥1 of the following: anticoagulant therapy, immunocompromised state, diabetes mellitus, prior radiation therapy to the head and neck, ear canal stenosis, exostoses, and nonintact tympanic membrane. (4) Clinicians should not routinely treat cerumen in patients who are asymptomatic and whose ears can be adequately examined. (5) Clinicians s...
Background: The advanced stage of the Maillard reaction, which leads to the formation of advanced glycation end products (AGE), plays an important role in the pathogenesis of angiopathy in diabetic patients and in the aging process. NE-(carboxymethyl)lysine (CML) is thought to be an important epitope for many of currently available AGE antibodies. However, recent findings have indicated that a major source of CML may be by pathways other than glycation. A distinction between CML and non-CML AGE may increase our understanding of AGE formation in vivo. In the present study, we prepared antibodies directed against CML and non-CML AGE.Materials and Methods: AGE-rabbit serum albumin prepared by 4, 8, and 12 weeks of incubation with glucose was used to immunize rabbits, and a high-titer AGE-specific antiserum was obtained without affinity for the carrier protein. To separate CML and non-CML AGE antibodies, the anti-AGE antiserum was subjected to affinity chromatography on a column coupled with AGE-BSA and CML-BSA. Two different antibodies were obtained, one reacting specifically with CML and the other reacting with non-CML AGE. Circulating levels of CML and non-CML AGE were measured in 66 type 2 diabetic patients without uremia by means of the competitive ELISA. Size distribution and dearance by hemodialysis detected by non-CML AGE and CML were assessed in serum from diabetic patients on hemodialysis. Results: The serum non-CML AGE level in type 2 diabetic patients was significantly correlated with the mean fasting blood glucose level over the previous 2 months (r = 0.498, p < 0.0001) or the previous 1 month (r = 0.446, p = 0.0002) and with HbAic (r = 0.375, p = 0.0019), but the CML AGE level was not correlated with these clinical parameters. The CML and non-CML AGE were detected as four peaks with apparent molecular weights of 200, 65, 1.15, and 0.85 kD. The hemodialysis treatment did not affect the high-molecular-weight protein fractions. Although the low-molecular-weight peptide fractions (absorbance at 280 nm and fluorescence) were decreased by hemodialysis, there was no difference before and after dialysis in the non-CML AGE-and CML-peptide fractions (1.15 and 0.85 kD fractions). Conclusions: We propose that both CML and non-CML AGE are present in the blood and that non-CML AGE rather than CML AGE should be more dosely evaluated when investigating the pathophysiology of AGE-related diseases.
Levels of tissue advanced glycation end products (AGEs) that result from nonenzymatic reactions of glucose and proteins are high in both diabetic and aging people. Irreversible AGE formation is based on increases in AGE-derived protein-to-protein cross-linking and is considered to be a factor contributing to the complications of diabetes. A novel inhibitor of advanced glycation, OPB-9195, belongs to a group of thiazolidine derivatives, known as hypoglycemic drugs; however, they do not lower blood glucose levels. We did studies to determine if OPB-9195 would prevent the progression of nephropathy in spontaneous diabetic rats. In vitro inhibitory effects of OPB-9195 on AGE formation and AGE-derived cross-linking were examined by enzyme-linked immunosorbent assay (ELISA) and SDS-PAGE, respectively. Otsuka-LongEvans-Tokushima-Fatty (OLETF) rats, a model of NIDDM, were used to evaluate the therapeutic effect of OPB-9195. Light microscopic findings by periodic acidSchiff (PAS) staining, the extent of AGE accumulation detected by immunohistochemical staining in the kidneys, the levels of serum AGEs by AGE-specific ELISA, and urinary albumin excretion were examined. OPB-9195 effectively inhibited both AGE-derived cross-linking and the formation of AGEs, in a dose-dependent manner in vitro. In addition, the administration of OPB-9195 prevented the progression of glomerular sclerosis and AGE deposition in glomeruli. Elevation of circulating AGE levels and urinary albumin excretion were dramatically prevented in rats, even at 56 weeks of age and with persistent hyperglycemia. We concluded that a novel thiazolidine derivative, OPB-9195, prevented the progression of diabetic glomerular sclerosis in OLETF rats by lowering serum levels of AGEs and attenuating AGE deposition in the glomeruli. Diabetes 46:895-899, 1997
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