Beyond the gluten-free diet:Innovations in celiac disease therapeutics

Celiac disease(CD)is an autoimmune disorder exacerbated by the ingestion of gluten in genetically susceptible individuals,leading to intestinal inflammation and damage.This chronic disease affects approximately 1%of the world’s po-pulation and is a growing health challenge due to its increasing prevalence.The development of CD is a complex interaction between genetic predispositions and environmental factors,especially gluten,culminating in a dysregulated immune response.The only effective treatment at present is a strict,lifelong gluten-free diet.However,adherence to this diet is challenging and often incomplete,so research into alternative therapies has intensified.Recent advances in under-standing the molecular and immunological aspects of CD have spearheaded the development of novel pharmacologic strategies that should provide more effec-tive and manageable treatment options.This review examines the latest inno-vations in CD therapies.The focus is on drugs in advanced clinical phases and targeting specific signaling pathways critical to the disease pathogenesis.We dis-cuss both quantitative strategies such as enzymatic degradation of gluten,and qualitative approaches including immunomodulation and induction of gluten tolerance.Innovative treatments currently under investigation include transglu-taminase inhibitors,which prevent the modification of gluten peptides,and nano-particle-based therapies to recalibrate the immune response.These new therapies not only promise to improve patient outcomes but are also expected to improve quality of life by reducing the burden of dietary restrictions.The integration of these new therapies could revolutionize the treatment of CD and shift the para-digm from strict dietary restrictions to a more flexible and patient-friendly thera-peutic approach.This review provides a comprehensive overview of the future prospects of CD treatment and emphasizes the importance of continued research and multidisciplinary collab-oration to integrate these advances into standard clinical practice.

Autoantibodies related to ataxia and other central nervous system manifestations of gluten enteropathy

Gluten ataxia and other central nervous system disorders could be linked to gluten enteropathy and related autoantibodies.In this narrative review,we focus on the various neuro-logical manifestations in patients with gluten sensitivity/celiac disease,immunological and autoimmune mechanisms of ataxia in connection to gluten sensitivity and the autoantibodies that could be used as a biomarker for diagnosing and following.We focused on the anti-gliadin antibodies,antibodies to different isoforms of tissue transglutaminase(TG)(anti-TG2,3,and 6 antibodies),anti-glycine receptor antibodies,anti-glutamine acid decarboxylase antibodies,anti-deamidated gliadin peptides antibodies,etc.Most studies found a higher prevalence of these antibodies in patients with gluten sensitivity and neurological dysfunction,presented as different neurological disorders.We also discuss the role of a gluten-free diet on the clinical improvement of patients and also on imaging of these disorders.

Transglutaminase 2 serves as a pathogenic hub gene of KRAS mutant colon cancer based on integrated analysis

BACKGROUND Colon cancer is acknowledged as one of the most common malignancies worldwide,ranking third in United States regarding incidence and mortality.Notably,approximately 40%of colon cancer cases harbor oncogenic KRAS mutations,resulting in the continuous activation of epidermal growth factor receptor signaling.AIM To investigate the key pathogenic genes in KRAS mutant colon cancer holds considerable importance.METHODS Weighted gene co-expression network analysis,in combination with additional bioinformatics analysis,were conducted to screen the key factors driving the progression of KRAS mutant colon cancer.Meanwhile,various in vitro experiments were also conducted to explore the biological function of transglutaminase 2(TGM2).RESULTS Integrated analysis demonstrated that TGM2 acted as an independent prognostic factor for progression-free survival.Immunohistochemical analysis on tissue microarrays revealed that TGM2 was associated with an elevated probability of perineural invasion in patients with KRAS mutant colon cancer.Additionally,biological roles of the key gene TGM2 was also assessed,suggesting that the downregulation of TGM2 attenuated the proliferation,invasion,and migration of the KRAS mutant colon cancer cell line.CONCLUSION This study underscores the potential significance of TGM2 in the progression of KRAS mutant colon cancer.This insight not only offers a theoretical foundation for therapeutic approaches but also highlights the need for additional clinical trials and fundamental research to support our preliminary findings.

Autoantibodies in chronic hepatitis C: A clinical perspective

Non-organ-specific autoantibodies and thyroid autoantibodies have been frequently found in chronic carriers of hepatitis C virus(HCV). With respect to endomysial antibodies and tissue transglutaminase, it is controversial whether the prevalence of glutenrelated seromarkers is higher in patients with HCV. In such cases, in addition to acknowledging any currently existing autoimmune disease, recognizing the risk of the patient developing an autoimmune disease during interferon(IFN)-based treatment must be a principle concern. From a clinical point-of-view, the presence of autoantibodies arouses suspicion that an autoimmunedisease may be present or may be precipitated by IFNbased HCV treatment. In this paper, we review the prevalence of autoantibodies in individuals with hepatitis C, the clinical significance of these autoantibodies, and the approach recommended for such situations.

Duodenal biopsy may be avoided when high transglutaminase antibody titers are present

AIM:To evaluate the predictive value of tissue transglutaminase (tTG) antibodies for villous atrophy in adult and pediatric populations to determine if duodenal biopsy can be avoided.METHODS: A total of 324 patients with celiac disease (CD; 97 children and 227 adults) were recruited prospectively at two tertiary centers. Human IgA class anti-tTG antibody measurement and upper gastrointestinal endoscopy were performed at diagnosis. A second biopsy was performed in 40 asymptomatic adults on a gluten-free diet (GFD) and with normal tTG levels.RESULTS: Adults showed less severe histopathology (26% vs 63%, P<0.0001) and lower tTG antibody titers than children. Levels of tTG antibody correlated with Marsh type in both populations (r=0.661, P<0.0001). Multiple logistic regression revealed that only tTG antibody was an independent predictor for Marsh type 3 lesions, but clinical presentation type and age were not. A cut-off point of 30 U tTG antibody yielded the highest area under the receiver operating characteristic curve (0.854). Based on the predictive value of this cut-off point, up to 95% of children and 53% of adults would be correctly diagnosed without biopsy. Despite GFDs and decreased tTG antibody levels, 25% of the adults did not recover from villous atrophy during the second year after diagnosis.CONCLUSION: Strongly positive tTG antibody titers might be sufficient for CD diagnosis in children. However, duodenal biopsy cannot be avoided in adults because disease presentation and monitoring are different.

Pathogenesis of coeliac disease:implications for treatment

INTRODUCTIONCoeliac disease(CD)is an enteropathy ,characterised by villous atrohy ,which occurs in genetically susceptible individuals .It affects mainly the proximal small intestine,and is caused by an intolerance to cereal storage proteins found in wheat ,barley and rye .

Effects of Nicotinamide on Mouse Skin Tumor Development and Its Mode of Action

Nicotinamide (NA), a naturally occuring vitamin and a protease inhibitor, has been shown to be effective in treating some skin ailments. It inhibits cell proiferaion and induces cell differentiation. This report shows the effects of NA on mouse skin tumor development and on the critical events involved in this process. NA reduced tumor growth, inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ornithine decarboxylase activity, but induced the transglutaminare activity which was inhibited by TPA under different experimental conditions.The effects of NA on ornithine decarboxylare (ODC) and transglutaminase (TG) indicated that nicotinamide (NA) probably programmmed the cells for their death in the natural course of time, i.e. programed cell death. This observation indicates that NA might be a better agent for the detailed study and for the better use in prevention of cancer alone or in combination with other drugs.

Transglutaminase inhibition:A therapy to protect cells from death in neurodegeneration?

Transglutaminases(TGs;E.C.2.3.2.13)are ubiquitous enzymes which catalyze post-translational modifications of proteins.TGs and TG-catalyzed post-translational modifications of proteins have been shown to be involved in the molecular mechanisms responsible for several human diseases.In particular,TG activity has been hypothesized to also be involved also in the molecular mechanisms responsible for human neurodegenerative diseases.In support of this hypothesis,Basso et al recently demonstrated that the TG inhibition protects against oxidative stress-induced neuronal death,suggesting that multiple TG isoforms participate in oxidative stress-induced cell death and that nonselective TG isoform inhibitors will be most effective in fighting oxidative death in neurological disorders.In this commentary,we discuss the possible molecular mechanisms by which TG activity could be involved in the pathogenesis of neurological diseases,with particular reference to neurodegenerative diseases,and the possible involvement of multiple TG isoforms expressed simultaneously in the nervous system in these diseases.Moreover,therapeutic strategies based on the use of selective or nonselective TG inhibitors for the amelioration of thesymptoms of patients with neurological diseases,characterized by aberrant TG activity,are also discussed.

Physio-pathological roles of transglutaminase-catalyzed reactions

Transglutaminases(TGs) are a large family of related and ubiquitous enzymes that catalyze post-translational modifications of proteins.The main activity of these enzymes is the cross-linking of a glutaminyl residue of a protein/peptide substrate to a lysyl residue of a protein/peptide co-substrate.In addition to lysyl residues,other second nucleophilic co-substrates may include monoamines or polyamines(to form mono-or bi-substituted/crosslinked adducts) or-OH groups(to form ester linkages) .In the absence of co-substrates,the nucleophile may be water,resulting in the net deamidation of the glutaminyl residue.The TG enzymes are also capable of catalyzing other reactions important for cell viability.The distribution and the physiological roles of TG enzymes have been widely studied in numerous cell types and tissues and their roles in several diseases have begun to be identified."Tissue" TG(TG2) ,a member of the TG family of enzymes,has definitely been shown to be involved in the molecular mechanisms responsible for a very widespread human pathology:i.e.celiac disease(CD) .TG activity has alsobeen hypothesized to be directly involved in the pathogenetic mechanisms responsible for several other human diseases,including neurodegenerative diseases,which are often associated with CD.Neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease,supranuclear palsy,Huntington's disease and other recently identified polyglutamine diseases,are characterized,in part,by aberrant cerebral TG activity and by increased cross-linked proteins in affected brains.In this review,we discuss the physio-pathological role of TG-catalyzed reactions,with particular interest in the molecular mechanisms that could involve these enzymes in the physio-pathological processes responsible for human neurodegenerative diseases.

谷氨酰胺转氨酶热稳定剂优化

谷氨酰胺转氨酶(Transglutaminase,TGase)能够催化蛋白质分子发生交联,被广泛应用于食品、医药和纺织等领域。为提高其热稳定性,研究了糖、盐及醇类等稳定剂对TGase在55℃下的半衰期[t_(1/2)(55℃)]的影响。结果表明,山梨醇、小麦蛋白、Na Cl和葡萄糖能延长TGase的t_(1/2)(55℃)。在此基础上进行正交实验,获得最佳的稳定剂配方:山梨醇50 g/L、小麦蛋白50 g/L、Na Cl 50 g/L、葡萄糖50 g/L。在该复合稳定剂保护下,TGase的t_(1/2)(55℃)和最适反应温度较对照(无稳定剂)分别提高59.73倍和10℃;室温(25℃)储存80 d的残余酶活率为73.84%,较对照提高62.79%。此研究结果将促进TGase的生产改进和应用拓展。

南极磷虾肉糜制作研发

为开发南极磷虾食品,开展南极磷虾肉糜制作研究。研究采用谷氨酰胺转氨酶、组织化植物蛋白与南极磷虾肉糜进行反应,考察NaCl、CaCl2以及反应时间对凝胶的影响;结果表明:添加2%NaCl,4%组织化植物蛋白,0.5%转谷氨酰胺酶、0.1%CaCl2充分混匀,于20℃下放置2h,制备得到的虾肉糜结构紧密,凝胶强度高,同时在外观上色泽红润,并通过食品质量安全检测。综上所述,该研发技术,可以为南极磷虾肉糜开发与生产起到理论指导作用。

Novel method for extracting exosomes of hepatocellular carcinoma cells

AIM: To develop a novel method for the rapid and efficient extraction of exosomes secreted by tumor cells.

Celiac disease serology in patients with different pretest probabilities: Is biopsy avoidable?

AIM: To establish the diagnostic performance of sev-eral serological tests, individually and in combination, for diagnosing celiac disease (CD) in patients with different pretest probabilities, and to explore potential se- rological algorithms to reduce the necessity for biopsy. METHODS: We prospectively performed duodenal biopsy and serology in 679 adults who had either high risk (n = 161) or low risk (n = 518) for CD. Blood samples were tested using six assays (enzyme-linked immunosorbent assay) that detected antibodies to tissue transglutaminase (tTG) and deamidated gliadin peptide (DGP). RESULTS: CD prevalence was 39.1% in the high-risk population and 3.3% in the low-risk group. In high-risk patients, all individual assays had a high diagnostic efficacy [area under receiving operator characteristic curves (AU ROC): 0.968 to 0.999]. In contrast, assays had a lower diagnostic efficacy (AU ROC: 0.835 to 0.972) in the low-risk group. Using assay combinations, it would be possible to reach or rule out diagnosis of CD without biopsy in 92% of cases in both pretest populations. We observed that the new DGP/tTG Screen assay resulted in a surplus compared to more conventional assays in any clinical situation. CONCLUSION: The DGP/tTG Screen assay could be considered as the best initial test for CD. Combinations of two tests, including a DGP/tTG Screen, might be able to diagnose CD accurately in different clinical scenarios making biopsy avoidable in a high proportion of subjects.

Extracellular quality control in the epididymis

The epididymal lumen represents a unique extracellular environment because of the active sperm maturation process that takes place within its confines. Although much focus has been placed on the interaction of epididymal secretory proteins with spermatozoa in the lumen, very little is known regarding how the complex epididymal milieu as a whole is maintained, including mechanisms to prevent or control proteins that may not stay in their native folded state following secretion. Because some misfolded proteins can form cytotoxic aggregate structures known as amyloid, it is likely that control/surveillance mechanisms exist within the epididymis to protect against this process and allow sperm maturation to occur. To study protein aggregation and to identify extracellular quality control mechanisms in the epididymis, we used the cystatin family of cysteine protease inhibitors, including cystatin-related epididymal spermatogenic and cystatin C as molecular models because both proteins have inherent properties to aggregate and form amyloid. In this chapter, we present a brief summary of protein aggregation by the amyloid pathway based on what is known from other organ systems and describe quality control mechanisms that exist intracellularly to control protein misfolding and aggregation. We then present a summary of our studies of cystatinrelated epididymal spermatogenic （CRES） oligomerization within the epididymal lumen, including studies suggesting that transglutaminase cross-linking may be one mechanism of extracellular quality control within the epididymis. （Asian J Androl 2007 July; 9： 500-507）

Calcium Glucarate Prevents Tumor Formation in Mouse Skin

Objective Calcium Glucarate (Cag), Ca salt of D-glucaric acid is a naturally occurring non-toxic compound present in fruits, vegetables and seeds of some plants, and suppress tumor growth in different models. Due to lack of knowledge about its mode of action its uses are limited in cancer chemotherapy thus the objective of the study was to study the mechanism of action of Cag on mouse skin tumorigenesis. Methods We have estimated effect of Cag on DMBA induced mouse skin tumor development following complete carcinogenesis protocol. We measured, epidermal transglutaminase activity (TG), a marker of cell differentiation after DMBA and/or Cag treatment and [3H] thymidine incorporation into DNA as a marker for cell proliferation. Results Topical application of Cag suppressed the DMBA induced mouse skin tumor development. Topical application of Cag significantly modifies the critical events of proliferation and differentiation TG activity was found to be reduced after DMBA treatment. Reduction of the TG activ

Celiac disease

Celiac disease （CD） is a common autoimmune disorder, induced by the intake of gluten proteins present in wheat, barley and rye. Contrary to common belief, this disorder is a protean systemic disease, rather than merely a pure digestive alteration. CD is closely associated with genes that code HLA-Ⅱ antigens, mainly of DQ2 and DQ8 classes. Previously, it was considered to be a rare childhood disorder, but is actually considered a frequent condition, present at any age, which may have multiple complications. Tissue transglutaminase-2 （tTG）, appears to be an important component of this disease, both, in its pathogenesis and diagnosis. Active CD is characterized by intestinal and/or extra-intestinal symptoms, villous atrophy and crypt hyperplasia, and strongly positive tTG auto-antibodies. The duodenal biopsy is considered to be the ＂gold standard＂ for diagnosis, but its practice has significant limitations in its interpretation, especially in adults. Occasionally, it results in a false-negative because of patchy mucosal changes and the presence of mucosal villous atrophy is often more severe in the proximal jejunum, usually not reached by endoscopic biopsies. CD is associated with increased rates of several diseases, such as iron deficiency anemia, osteoporosis, dermatitis herpetiformis, several neurologic and endocrine diseases, persistent chronic hypertransami-nasemia of unknown origin, various types of cancer and other autoimmune disorders. Treatment of CD dictates a strict, life-long gluten-free diet, which results in remission for most individuals, although its effect on some associated extraintestinal manifestations remains to be established.

Gluten sensitive enteropathy in patients with iron deficiency anemia of unknown origin

AIM: To determine the prevalence of gluten sensitive enteropathy (GSE) in a large group of patients with iron deficiency anemia (IDA) of obscure origin. METHODS: In this cross-sectional study, patients with IDA of obscure origin were screened for GSE. Anti- endomysial antibody (EMA) and tissue transglutamin- ase antibody (tTG) levels were evaluated and duodenal biopsies were taken and scored according to the Marsh classification. The diagnosis of GSE was based on a positive serological test and abnormal duodenal histol- ogy. Gluten free diet (GFD) was advised for all the GSE patients. RESULTS: Of the 4120 IDA patients referred to our Hematology departments, 206 (95 male) patients were found to have IDA of obscure origin. Thirty out of 206 patients (14.6%) had GSE. The mean age of GSE pa- tients was 34.6 ± 17.03 (range 10-72 years). The female to male ratio was 1.3:1. Sixteen patients had Marsh 3,12 had Marsh 2, and 2 had Marsh 1 lesions. The sever- ity of anemia was in parallel with the severity of duode- nal lesions. Twenty-two GSE patients (73.3%) had no gastrointestinal symptoms. Fourteen GSE patients who adhered to GFD without receiving iron supplementation agreed to undergo follow up visits. After 6 mo of GFD, their mean hemoglobin levels (Hb) increased from 9.9 ± 1.6 to 12.8 ± 1.0 g/dL (P < 0.01). Interestingly, in 6 out of 14 patients who had Marsh 1/2 lesions (e.g. no villous atrophy) on duodenal biopsy, mean Hb increased from 11.0 ± 1.1 to 13.1 ± 1.0 g/dL (P < 0.01) while they did not receive any iron supplementation. CONCLUSION: There is a high prevalence (e.g. 14.6%) of GSE in patients with IDA of obscure origin. Gluten free diet can improve anemia in GSE patients who have mild duodenal lesions without villous atrophy.

Transglutaminase 3 expression in C57BL/6J mouse embryo epidermis and the correlation with its differentiation

Epidermal-type transglutaminase 3 (TGM3) is involved in the cross-linking of structural proteins to form the cornifiedenvelope in the epidermis. In the present study, we detected the expression of TGM3 in the mouse embryo using RT-PCR.TGM3 mRNA is weakly presented from E11.5 to E14.5 and increases significantly from E15.5 to birth. Then wedetermined the spatial and temporal expression pattern of TGM3 in the skin and other organs by in situ hybridization. Wefound a deprivation of TGM3 in skin at E11.5, while a rich supply in periderm cells and a weak expression in basal cellsfrom E12.5 to E14.5. From the period of E15.5 to E16.5, after keratinization in the epidermis, TGM3 was expressed inthe granular and cornified layers. The electron microscopic observation of the C57BL/6J mouse limb bud skin develop-ment provided several morphological evidences for the epidermal differentiation. The above findings suggest that theexpression of TGM3 plays a important role in the epidermis differentiation in embryogenesis.

Cystamine ameliorates liver fibrosis induced by carbon tetrachloride via inhibition of tissue transglutaminase

AIM： To investigate the anti-fibrosis effect of the tissue transglutarninase （tTG） specific inhibitor cystarnine on liver fibrosis. METHODS： Sixty-eight male Sprague Dawley rats were divided into three groups： normal control, liver fibrosis control and cystamine-treated group. Liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride （CCl4）, and Cystarnine was administrated by intraperitoneal injection starting 2 d before the first administration of CCl4. Animals in each group were further divided into 2 subgroups according to two time points of 4 wk and 8 wk after treatment. Hepatic function, pathological evaluation （semi-quantitative scoring system, SSS） and liver hydroxyproline （Hyp） content were examined. Real-time PCR was used to detect the expression of tTG, smooth muscle alpha actin （α-SMA）, tissue inhibitor of metalloproteinase 1 （TIMP-1） and collagen-1 mRNA. The expressions of tTG and α-SMA protein were detected by Western Blotting. RESULTS： Eight weeks after treatment, the SSS score of liver was significantly less in the cystamine group than that in the fibrosis control group （P 〈 0.01）. The levels of alanine arninotransferase （ALT） and total bile acid （TBA） at the 4 wk and 8 wk time points were decreased in the cystamine group compared with those in fibrosis controls （P 〈 0.01）. Liver hydroxyproline content at the 4 wk and 8 wk time points showed a substantial reduction in the cystamine group compared to fibrosis controls （P 〈 0.01）. The expression of tTG, α-SMA, collagen-1, TIMP-1 mRNA and tTG, as well as α-SMA protein was downregulated in the cystamine group compared to fibrosis controls. CONCLUSION： Cystamine can ameliorate CCl4 induced liver fibrosis and protect hepatic function. The possible mechanism is related to the reduced synthesis of the extracellular matrix （ECM） caused by the inhibition of hepatic stellate cell activation and decreased expression of TIMP-1.

Celiac disease in patients with presumed irritable bowel syndrome:A case-finding study

AIM:To estimate the prevalence of celiac disease(CD) in adult patients with presumed irritable bowel syndrome(IBS) .METHODS:Between March 2005 and December 2008,742 consecutive patients(293 male,median age 43 years,range 18-69 years) fulfilling the Rome Ⅱ criteria for IBS were prospectively enrolled in the study.IBS was diagnosed via self-completed Rome Ⅱ modular questionnaires.Anti-tissue transglutaminase(anti-tTG) serology was checked to initially recognize possible CD cases.Patients with a positive test were offered endoscopic duodenal biopsy to confirm the diagnosis of CD.RESULTS:Thirty two patients(15 male,median age 41 years,range 19-59 years) were found to have organic diseases other than CD.Twenty four patients tested positive for anti-tTG antibodies,and duodenal biopsies confirmed the diagnosis in all of them.Thus,in this patient population with presumed IBS,3.23% actually had CD.CONCLUSION:CD is common in patients with presumed IBS.Routine screening for CD in patients with symptoms of IBS is recommended.